Author Index with Abstracts

Listed below are the papers published in the Journal (or its forerunner, the Australian Computer Journal) since it was first published in 1967. We are extremely grateful to Godfrey Lance, Editor of the Journal 1968-71, for giving his time to enter this data.

We believe this data to be accurate. However, if you spot any errors please let me know at jrpit@cs.flinders.edu.au.

The first page of journal papers and the full-text of most conference papers are available in either PDF or postscript format.

Aa, T. V., Eeckhout, L., Goeman, B., Vandierendonck, H., Achteren, T. V., Lauwereins, R. and Bosschere, K. D. (2002). Optimizing a 3D Image Reconstruction Algorithm: Investigating the Interaction between the High-Level Implementation, the Compiler and the Architecture. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Abel, D. E. and Rout, T. P. (1993). Defining and Specifying the Quality Attributes of Software Products. Australian Computer Journal 25(3): 105-112.

The technique of Software Quality Engineering permit the high level specification of quality requirements of software products, and suggest means by which these specifications can be actualised in terms of engineering attributes. The development of an international standard for Software Product Evaluation has resulted in the definition of a standard suite of quality characteristics of software. This paper demonstrates how these characteristics may be used in the Software Quality Engineering technique, and describes a prototype tool which assists and drives much of the specification process.

Abel, D. J. and Smith, J. L. (1984). A Data Structure and Query Algorithm for a database of Areal Entities. Australian Computer Journal 16(4): 147-154.

Data structures for geometric information systems desirably should support the efficient execution of a number of query types based on spatial relationships. This paper pursues this goal by proposing a data structure for entities of type "area". The approach is based on addressing* an entity by a limited number of subquadrants which together cover it. An algorithm for the rectangle retrieval problem is presented which provides better performance than a reported algorithm. The point inclusion problem is framed as a degenerate case of an extended form of the rectangle retrieval problem and is shown to be solvable with costs proportional to the logarithm of the number of entities in the database.

Abel, D. J. and Smith, J. L. (1984). A Simple Approach to the Nearest-Neighbour Problem. Australian Computer Journal 16(4): 140-146.

The nearest-neighbour problem deals with the identification of the closest point to a given query point. It is a classical problem of computational geometry with a wide range of applications. Many algorithms have been reported but require specialist data structures not supporting solution of other problems. In this paper a simple but efficient approach based on a data structure accommodating a number of problems in computational geometry is presented. The data structure is novel in indexing points by a quadtree-like decomposition, with the search strategy exploiting properties of the decomposition.

Abel, D. J. and Williams, W. T. (1981). NEBALL and FINGRP: New Programs for Multiple Nearest-Neighbour Analyses. Australian Computer Journal 13(1): 24-25.

NEBALL assumes the prior existence, for n elements (n<= 150), of an interelement distance matrix of order n. Each element is then associated with the complete ordered set of its (n-1) matches in successive subsets of r (r=1 to n) is compared with random expectation, and a measure of discrepancy, delta r, is written away. It is shown that delta r is constrained within the limits +- 0.25. Program FINGRP accepts the matrix of delta r values and submits it to a non-heirarchical classificatory procedure at externally-specified levels of similarity, The result is a non-exclusive set of homogeneous groups of elements.

Abel, D. J. and Williams, W. T. (1981). Program INVER Revisited. Australian Computer Journal 13(1): 26.

The original program INVER computed a distance-matrix between attributes of mixed types. Though generally effective, it occasionally encountered difficulties, largely as a result of unusual data-configurations which had not been forseen. These have been identified and a new version written which appears to overcome the problems.

Abel, D. J. and Williams, W. T. (1984). PREPOL: A Method to Convert a Mixed Data Set to All Numeric. Australian Computer Journal 16(1): 33-35.

There are available in the literature classificatory techniques which are attractive for the analysis of problems with large numbers of individuals because their solution times are linearly proportional to the number of individuals. They are, however, restricted to numeric attributes only. This paper presents a procedure to transform the non-numeric attributes in a mixed data set to all numeric, which can then be processed by such techniques. Preliminary experience suggests that this composite algorithm provides solutions whose ease of interpretation is comparable to those generated by a commonly-used agglomerative technique.

Abramson, D. A. and Egan, G. K. (1988). An Overview of the RMIT/CSIRO Parallel Systems Architecture Project. Australian Computer Journal 20(3): 113-121.

This report discusses the RMIT/CSIRO parallel systems architecture project. It presents some important aspects of the architecture of a dataflow machine being constructed. The language systems are briefly described. The structure of a multiprocessor emulation facility is described, as well as some simulation results. This report is intended as an introductory paper on some of the technical aspects of the project.

Abramson, D. A., Ramamohanarao, K. and Ross, M. (1989). A Scalable Cache Coherence Mechanism Using a Selectively Clearable Cache Memory. Australian Computer Journal 21(1): 2-12.

In this paper we propose a scalable solution to the cache coherence problem for write through caches which uses advice from software on when to enforce coherence. The solution removes shared structures from the cache efficiently, and thus forces the subsequent cache misses to proceed to main memory. Shared structures are removed by a novel selectively clearable memory chip. The chip is an extension of already available clearable devices. The shared structures are removed after mutual exclusion has been obtained. This guarantees that the cache cannot hold stale copies of the data. A number of optimisations are described which improve the performance of the scheme. These optimisations allow a write back cache as well as write through. They also increase the selectivity of the clear operation for caches with a large number of sets. Some simulation studies indicate expected performance of the system.

Ahlgren, B., Bjorkman, M. and Gunningberg, P. (1996). Towards Predictable ILP Performance - Controlling Communication Buffer Cache Effects. Australian Computer Journal 28(2): 66-71.

Cache memory behaviour is becoming more and more important as the speed of CPUs is increasing faster than the speed of memories. the operation of caches are statistical which means that the system level performance becomes unpredictable. In this paper we investigate the worst case behaviour of cache line conflicts in the context of communication protocols implemented using Integrated Layer Processing. The goal of our work is to control the cache by placing communications buffers and code in non-conflicting positions in the cache. the result would be higher and more predictable performance. Our first results indicate that the worst case behaviour can be up to almost four times slower than the best case.

Aiken, J. D. (1971). An Introduction to Management Information Systems. Australian Computer Journal 3(3): 98-105.

This paper sets out points for consideration and general guide lines in the development of the Management Information System (MIS) Proposal. It does not purport to give a ready made answer to all the problems involved in MIS but provides a workable framework in which to design MIS.

Akiyama, T., Sakai, S., Umigai, A., Hara, T., Tsukamoto, M. and Nishio, S. (2002). Design and Implementation of DB-MAN Alpha: Does Database Migration Work Well in a Real Environment?. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X. Z., Ed. ACS. Full Text.

Akl, S. G. (1980). The Minimal Directed Spanning Graph for Combinatorial Optimization. Australian Computer Journal 12(4): 132-136.

This paper introduces a graph theoretic structure for combinatorial optimization: the minimal directed spanning graph. The new structure - a generalisation of the minimal spanning tree for directed graphs - is used to design an approximation algorithm for the asymmetric travelling salesman problem. Experiments with the algorithm are described which suggest that the future studies of the applicability of the new structure to the solution of other combinatorial optimization problems might prove worthwhile.

Albacea, E. A. (1995). Basic Parallel Algorithmic Techniques for Shared-Memory Machines. Australian Computer Journal 27(2): 51-61.

Most parallel algorithms have lately been analysed using the Parallel Random Access Machine Model (PRAM). Due to the popularity of the PRAM, several basic PRAM techniques were formulated in order to facilitate the design and analysis of most problems on lists, trees, and graphs. Prefix, list ranking, and tree contraction are three of the most basic of these techniques. In this paper, we survey the existing algorithms and applications of these three basic PRAM techniques. We also show that list ranking can be reduced to tree contraction and vice versa. To make this reduction result useful, a new tree contraction algorithm that does not use list ranking as a subprocedure is introduced. Then, we combine some of these basic techniques to form another higher-level technique called parallel tree-structured computation. Included in tree-structured computation are three types of tree computations, namely: adjacency lists computation, bottom-up computation tree evaluation, and top-down computation tree evaluation. Applications of this higher-level technique are also surveyed.

Allen, J. G. and Jin, J. S. (2002). Enhancing Screen Teleconferencing with Streaming SIMD Extensions. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Allinson, C. (2002). Information Systems Audit Trails; An Australian Government Survey. Journal of Research and Practice in Information Technology 34(1): 47-64. First Page.

Governments have major information holdings on computer systems. This electronically stored information is subject to legislative requirement. However, history has shown that security in relation to the recording of activity against access to information held on Australian government computer systems has been poor and a cause for concern. A brief definition of information systems audit trails is given, with emphasis on national and international standards requirements. Aspects of Australian privacy legislation are discussed. Background, detail and results of an Australia wide survey of all government departments is given and contrasted with particular results of a survey conducted by the Australian Commonwealth Privacy Commission four years previous. It is shown that most organisations studied generate and retain audit trails but the approach is not consistent nor is it comprehensive. Within a four year period there is evidence to suggest that government organisations are increasingly more inclined to generate audit trails. It is also suggested that due to the inadequate and non-compliant security processes and procedures these materials would not withstand a serious legal challenge.

Allison, L. (1993). Applications of Recursively Defined Data Structures. Australian Computer Journal 25(1): 14-20.

A circular program contains a data structure whose definition is self-referential or recursive. The use of such a definition allows efficient functional programs to be written and can avoid repeated evaluations and the creation of intermediate data structures that would have to be garbage collected. This paper uses circular programs in various ways. To implement memo-structures and explicit search-trees to hold solutions to constraint-satisfaction problems.

Allison, L. (2000). Generator and Search Objects in Java. Journal of Research and Practice in Information Technology 32(1): 3-12. First Page.

Generator classes are defined in the object-oriented programming language Java by using continuation-style programming. Generator objects are used to write Prolog-like programs in Java to solve combinatorial constraint satisfaction problems. A collection of generators oriented to world wide web applications is demonstrated on searches for HTML pages.

Altmann, R. A., Hawke, A. N. and Martin, C. D. (1988). An Integrated Programming Environment Based on Multiple Concurrent Views. Australian Computer Journal 20(2): 65-72.

Traditional programming environments typically provide a collection of loosely-connected, separate programme development tools such as text editors, compilers, linkers and debugging aids. Integrated programming environments combine the functions of these separate tools into a single program development system, presenting the user with a single interface to the system. This paper describes progress on an integrated programming environment, called MultiView, which presents the user with a variety of views of the program under development, each of these views being automatically updated when changes are made to the program using any other view. In order to improve performance and to ensure that all displayed views are up to date. MultiView has been implemented as a collection of parallel processes communicating via message passing. MultiView is expected to be one of the first applications for the Leopard multiprocessor workstation, also under development at the University of Adelaide.

An, J., Chen, H., Furuse, K., Ishikawa, M. and Ohbo, N. (2002). The Complex Polyhedra Technique: An Index Structure for High-Dimensional Space. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Anderson, M. and Wallace, C. S. (1988). Some Comments on the Implementation of Capabilities. Australian Computer Journal 20(3): 122-133.

There has been much research on capabilities and the areas to which they can be applied. Various approaches have been proposed and a number of systems have been constructed. This paper examines the two main methods employed for implementing capabilities, i.e. tagging and partitioning, as well as a third method: sparseness. The effects of a capability implementation on revocation, garbage collection and abstract objects are also examined.

Anderssen, R. S. (1968). On the Reliability of Finite Difference Representations. Australian Computer Journal 1(3): 173-177.

For general initial-boundary value problems for the simple heat conduction equation, Osborne (1968) has shown that the solutions of the generalised Crank-Nicholson finite difference representations (f.d.r.) of these initial-boundary value problems behave for large t in the same way as the corresponding exact solutions of these problems. Since this result does not hold for all stable f.d.r. of general initial-boundary-value problems for general second order parabolic equations, the concept of a reliable f.d.r. is introduced and conditions are derived on the basis of this concept which ensure that the above mentioned correspondence between the solutions of the f.d.r. and the exact solutions of the corresponding separable problems is in some sense preserved for large t.

Ang, C. C. and County, E. J. P. (1988). An Experiment in Modelling Communication Protocols using NPNs. Australian Computer Journal 20(2): 73-78.

This paper describes the results of some work done recently in the area of communication protocol modelling using a formal description technique. The communication protocol chosen to be modelled is a section of the yet unfinalised OSI FTAM communication protocol (ISO-DIS 8571) (ISO, 1986). The FTAM communication protocol is specified in three sections - the basic file protocol, the basic bulk data transfer protocol and the error recovery protocol. Due to time limitations, the basic bulk data transfer protocol and the error recovery protocols were not modelled. The part of the FTAM protocol that was modelled is the basic file protocol. The formal description technique used is an extension of Petri Nets (Reisig 1985) known as Numerical Petri Nets (NPN) (Symons, 1978). The NPN model constructed was later verified using the PROTEAN validation tool.

Anh, V. N. and Moffat, A. (2002). Improved Retrieval Effectiveness Through Impact Transformation. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Ardagh, D. (2001). Public Education in Computer Usage: An Ethico-Political Rationale. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Routine provision of computer education and training by public educational institutions for all students at public expense is not the norm in many first world nations. "User pays" and other educational policy norms suggested by economic rationalist assumptions prevail. The paper tries to identify and criticise these from a Neo-Aristotelian point of view, arguing that if politics and policy is suspended from an ethics of equal empowerment to virtue, states in justice have duties to educate and train in vital skills needed by citizens to attain wellbeing. Less affluent citizens have a right to be assisted to exercise their right to knowledge and less affluent nations likewise have strong claims on affluent first world nations.

Arikawa, M. and Kambayashi, Y. (1991). Dynamic Name Placement Functions for Interactive Map Systems. Australian Computer Journal 23(4): 133-147.

Most tedious tasks of generating maps can be done easily by computers, except for placing names on the maps. This seemingly simple task is, in fact, remarkably complex. This paper first defines the name placement problems and their importance. Then it determines the complexity of the problems, and presents some principles of name placement for interactive map systems.

Arora, R. and Subramanian, R. K. (1979). SDMRU - A Paging Algorithm. Australian Computer Journal 11(4): 122-126.

The least recently used paging algorithm is popularly known, yet has the disadvantage of producing continuous page faults when a cyclic reference of m+1 or more pages is made with m pages in the main memory. This paper proposes a semi-dynamic algorithm, SDMRU, which avoids such continuous page faults over relatively high ranges of memory size when tested with constructed programs of characteristic and representative behaviour. The implementation is simple. A suggestion for modifying it into a demand prepaging algorithm is also made. The suitability of SDMRU in a multiprogramming environment is also discussed.

Arora, R. K., Rana, S. P. and Sharma, N. K. (1981). On the Design of Process Assigner for Distributed Computing Systems. Australian Computer Journal 13(3): 77-82.

In distributed operating systems, an important facility to be provided is the process assigner. The assigner maps processes of a distributed program in processors for execution so as to optimize system performance. In this paper we have stated the properties of assigner and formalised its conceptual structure. Three implementation strategies are then presented for the assigner, and their merits and demerits discussed.

Asenjo, P. B. (1997). Internet Ethics' Bibliography. Australian Computer Journal 29(1): 31-34.

Asenjo, P. B. (1997). Key Ethical Concepts for the Internet and for Ethical Codes of Computer Professionals. Australian Computer Journal 29(1): 2-5.

In this research, five hundred letters were sent to computer science professionals to ask for all of the ethical codes of their organisations and enterprises. Fifteen different codes were received. A computerised analysis of the contents of each code was undertaken. Forty ethical principles or rules were identified, and these were listed in decreasing order of quantitative appearance in the codes. Those ethical principles appearing at least 17 times (nearly half of the maximum number of appearances) were compared to four key ethical concepts identified by Mason (1986) as central to the future success of computing. The results of this research and another survey by Berleur and Brunnstein (1996) show that codes of ethics of IS professionals do treat as very important the four ethical issues singled out by Mason. Arguments by Platt and Morrison (1995) indicate that these results provide positive evidence that IS professionals are addressing social and ethical concerns that will advance and support the Internet and future global computer networks.

Ashenden, P. J. and Marlin, C. D. (1988). A Behavioural Specification of Cache Coherence. Australian Computer Journal 20(2): 50-57.

Multiprocessor systems with a shared memory are of increasing interest, because of their flexibility, incremental expandability, and potentially low cost. To reduce bus contention and to improve memory access time, such multiprocessor systems commonly incorporate a memory cache per processor. The use of memory caches leads to the need to ensure that the contents of the caches are coherent with each other and with the shared memory; this is the so-called cache coherence problem. A number of strategies have been proposed to overcome this problem, but little is known about their advantages and disadvantages. This paper contributes to the study of cache strategies by proposing a formal model of cache coherence. This model, which is an information structure model, is described and its application illustrated by outlining how it can be used to describe the cache coherence strategy used in the Futurebus standard.

Ashley, P., Broom, B. and Vaudenwauver, M. (1999). An Implementation of a Secure Version of NFS including REBAC. Australian Computer Journal 31(2): 54-64.

The NFS protocol provides transparent remote access to shared file systems across networks. It is very popular particularly in Unix networks where it is probably the most common distributed file system technology. NFS however is rarely used outside closed protected networks, because its security is notoriously weak. In 1998 Sun Microsystems released what is considered the first attempt at providing comprehensive security to NFS: a security flavour called RPCSEC_GSS based on Kerberos V5 and the GSS-API. The main benefit of this version over previous versions is that for the first time each NFS file access call can be protected. This paper outlines our efforts to secure NFS producing a security solution with even greater functionality. The major new functionality is that users may optionally use an access control system based on role based access control (RBAC). RBAC allows users to log in, be provided with a role, and use this to transparently access their remote files through secure NFS. There are also other advantages provided, for example security for the mount protocol and the option of public-key technology for authentication and key distribution. NFS has been secured with SESAME V4 and the practicality and performance of this mechanism has been demonstrated by modifying the Linux kernel and NFS utilities.

Atkinson, D. and Lam, A. (1999). A Case Study Exploration of Groupware Supported Workflow. Australian Computer Journal 31(4): 124-130.

A medium-sized information technology company was the site for a case study exploration of two workflow systems, a tender assessment system and a services request management system that were developed in the groupware software, Lotus Notes. The main objective of the research was to explore the features of Notes that contributed to or detracted from successful development and implementation of the systems. An additional objective was the exploration of organisational impacts of the workflow systems. Fifteen hours of interviews with developers, managers and users were undertaken. Findings were that Notes is an easy environment in which to develop basic workflow systems.Email is integrated with form-based document databases to provide basic workflow features. More complex workflow systems requiring exception handling via multiple flow paths and/or numeric computation and processing were problematic. The non-relational database structure was also seen as a limitation. In part the limitations may be attributed to the education and training of the developers. Managers were positive about the increased control the systems gave them. Users found the interface easy to use and were positive about the usefulness of the system, however reservations were expressed about the increased managerial control and the dehumanisation of the workplace.

Austin, B. J. (1977). Job Scheduling by a Front End Computer. Australian Computer Journal 9(3): 107-111.

The paper describes a scheduler operating in a front end computer (a Control Data 3600) which selects jobs to be sent to the main processor (a CYBER 76). The scheduler distinguishes between purely computational jobs and those which require disc packs or magnetic tapes (and therefore must wait for operator attention). Computational jobs are selected by an algorithm which aims to produce a mixture of many short and fewer long jobs. Jobs requiring demountable media are selected in an empirically determined "mix" which is intended to utilise all types of tape and disc drive fully. The scheduler is cognisant of the state of job execution within the CYBER 76 via a single status bit. The operators control the throughput of jobs requiring tapes or disc packs, and they can adjust parameters to cater for cases of one or more drives being temporarily unavailable. In spite of the limited nature of these control mechanisms, the scheduler can cope effectively with the many states of the system normally encountered in a day - heavily loaded prime shift, lightly loaded evening shift and the transition between these states.

Austin, B. J. (1978). Port Management in the CYBER76-CSIRONET Interface. Australian Computer Journal 10(3): 98-101.

The paper describes the port management techniques which have been found necessary between CSIRONET and the CYBER76. Contention mechanisms exist between independent halves of CSIRONET, by way of separate PDP11 Host Interfaces. Central processes providing interactive or remote job entry service are provided with separate sets of ports, as are parallel versions under development. Error recovery procedures provide for failure of a central process or a PDP11 Host Interface.

Austin, B. J., Hanlon, P. P. and Russell, J. J. (1974). Job Scheduling in a Monoprogrammed Environment. Australian Computer Journal 6(1): 26-29.

This paper describes an algorithm for the computer selection of jobs for execution. Its application in a monoprogrammed environment is discussed, but the technique could be applied in a multistream system. The aim of the scheduling procedure is generally to run short jobs first, but not to delay long jobs indefinitely. In addition, provision is made for a user-selected higher or lower priority with concomitantly increased or decreased charging rates. The scheduling algorithm is intended to select the next job from all the candidates for execution without undue overhead, in particular where jobs have to be rejected after an initial scan of their control statements has indicated that some essential resources are unavailable. An important special case of this phenomenon relates to jobs requiring named reels of magnetic tape. The scheduling technique has provision for putting such jobs 'to one side' and for informing the operators of tape mounting requirements, without holding up the stream processing.

Austin, B. J. and Holden, T. S. (1969). Recent Developments of the DAD System. Australian Computer Journal 1(4): 201-207.

The paper gives a description of recent developments of and experience with the monitor system of the C.S.I.R.O. computer at Canberra, a Control Data 3600. A summary of the general principles of the monitor is given, but without the detail of a description already published. The validity of various design decisions is discussed, particularly in the areas of job scheduling, and of management of the drum and disc backing stores. A technique which enables the time-sharing of main jobs ("Breakin") is described and its use in connection with the graphical display and keyboard displays is shown. A recent addition to the system is a Digital Equipment PDP-8 computer, with five teletypes. These teletypes have been successfully incorporated into the system alongside the CRT (character) displays. A discussion of the techniques required for the incorporation is given.

Australian Academy of Science and CSIRO (1979). A Survey of Scientific Data Systems in Australia. Australian Computer Journal 11(2): 74-75.

Avison, D. E. (1991). Action Programmes for Teaching and Researching in Information Systems. Australian Computer Journal 23(2): 66-72.

Information systems is a practical discipline and teaching and research should be relevant to the world of the information systems practitioner. Action programmes aim to reflect the pragmatic view of the discipline of information systems, action learning in our teaching and action research in our research. This paper discusses the advantages and problems of these programmes and in each case describes one project in detail.

Avison, D. E. and Wood-Harper, A. T. (1986). Multiview - An Exploration in Information Systems Development. Australian Computer Journal 18(4): 174-179.

This paper presents an overview of conventional and alternative methodologies for developing information systems. It suggests that the search for an ideal methodology is illusory. Information systems development is an area where certain principles, tools and techniques may be appropriate in some situations but not in others. Multiview is a pragmatic approach, developed using action research methods. It has proved useful in a number of situations, frequently in small businesses developing applications using microcomputers. It incorporates many aspects of other methodologies and also attempts to incorporate the views of the many players involved in developing information systems at each stage of their development. It is not offered as a panacea, indeed the paper discusses problems in the approach and reflects on further work that might make it more useful to practitioners.

Avouris, N. M. and Solomos, K. G. (2001). User Interaction with Web-based Agents for Distance Learning. Journal of Research and Practice in Information Technology 33(1): 16-29. First Page.

Design of user interaction of web-based agent systems necessitates new approaches in relation to control, task allocation, transparency and user's privacy protection. This paper investigates interaction of users with multiple agents with special focus on web-based learning systems. A proposed new architecture is described, which allows for adaptive agents' participation in the educational process, while maintaining the user as the principal locus of control in user-system interaction. The issue of user modelling, the characteristics of the conceptual model of the user and the implications of the heterogeneity of resources are also discussed in the frame of an open web-based learning environment.

Bailes, P. A. (1984). A Rational Pascal. Australian Computer Journal 16(4): 155-163.

Even though Pascal is a popular teaching language, it has the disadvantage that it imposes a variety of semantic and syntactic restrictions upon its users. This paper offers a solution to one part of the problem by providing a more helpful syntax. In particular, the new syntax encourages the expression of algorithms in a top-down manner. Implementation by preprocessing into Pascal is straightforward.

Bailes, P. A., Chapman, M., Chia, M. and Peake, I. (1994). Generic Re-Engineering Environment Design Criteria: An Evaluation of the Software Refinery. Australian Computer Journal 26(4): 151-157.

The quality of software re-engineering tools depend on that of the generic environments used in their construction. Because re-engineering is extremely challenging, too much so even for full automation, generic re-engineering environment design criteria emphasise linguistic expressiveness and interaction with persistent repositories for program representations. In our experience, including the development of a generic architecture for re-engineering applications, one enviranment in particular, the Software Refinery, goes a long way to satisfying these criteria. However, there is room for improvement, especially in moving towards an open, truly-persistent multi-accessible repository.

Baker, E. (1990). Communication the Other Half of Office Automation. Australian Computer Journal 17(3): 113-119.

Office automation has been dominated by computers but communication is now having an impact. The paper provides evidence from a recent survey that facsimile and electronic mail are being adopted rapidly in Australia. Also, the latest workstation designs indicate that voice communication, so predominant in offices, is finally being integrated with computers. A model representing integrated voice and computer systems of the near future is presented. The overlap with teleconferencing is noted, and merging of teleconferencing with office automation is predicted. As communication and computers are combined, some behavioural and organisational issues arise. Among those discussed in the paper are (1) electronic reproduction of face-to-face meetings compared to alternative meeting options (2) how user behaviour is affected differently by computer and voice communication systems and (3) opportunities offered by shared-space modes of working.

Baker-Finch, C. A. (1984). Algebraic, Operational and Denotational Semantics of the Lambda Calculus. Australian Computer Journal 16(3): 96-101.

This paper presents a proof of the congruence of an operational and a denotational semantics of the lambda calculus. We adopt an algebraic notion of congruence and use an algebraic style of semantics to unify the two more traditional definitions.

Balicki, J. (2001). Multi-Criterion Optimisation of Distributed System Performance by Evolutionary Task Assignments. Journal of Research and Practice in Information Technology 33(2): 173-185. First Page.

A careful task assignment in a distributed computer system may reduce the workload of a bottleneck computer. It can decrease the cost of computation if the computer sort selection is applied with the task assignment. The total system performance is another measure that can be minimised by the computer sort selection with the task assignment. An extended problem of task allocation can be formulated as a multiobjective combinatorial optimisation question,which is solved by an adaptive evolutionary algorithm. It is applied by finding the subset of Pareto-optimal solutions. Then, a module scheduling is used to maximise the probability of completing tasks with timing correctness.

Banerji, D. K. and Kaushik, S. (1984). On Combinational Logic for Sign Detection in Residue Number Systems. Australian Computer Journal 16(3): 90-95.

This paper is concerned with the algebraic sign detection of a number in a Residue Number System. The proposed solution is applicable only to non-redundant systems. The method utilises a systematic decomposition of the sign function S. Starting with the canonical sum-of-products expression for S, we transform the expression to a form whose realisation is simpler than the minimal sum-of-products realisation. In comparison to minimal sum-of-products realisation, our method provides up to 88 percent saving in the logic complexity for determining the sign of a residue number.

Barney, D., Haley, D. and Nikandros, G. (2001). Calculating Train Braking Distance. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

The paper discusses the development of an IBM PC based tool, for calculating train braking distances for various train classes on a rail network. There is discussion on current industry practice and the limitations of that practice, the concept of the tool itself, including the assumptions made, the strategy adopted to minimise the risk of incorrect calculations, and the results of adopting that strategy.

Barr-David, F. (1971). Computing in the 70's. Australian Computer Journal 3(4): 150-155.

The information explosion is putting new pressures on managers and quick access to detailed business information is becoming essential for effective decision making. The computer industry is responding constructively to this management problem. Computer terminal systems can now link managers to bigger direct access mass data storage facilities. But data base systems present programming problems beyond the resources of most users. Generalised procedure packages developed by computing organisations for specific industries will become increasingly important in this decade. Simulation or modelling on computer problem situations allowing many alternative solutions, is another technique the computing industry is perfecting to help managers in rational decision making.

Barry, J. M. (1974). Application of the Finite Element Method to Elliptic Problems. Australian Computer Journal 6(2): 51-60.

The finite element method is now a well established tool in structural engineering. The more recent applications of this technique to elliptic self-adjoint problems are described with several elements using high order polynomial approximating functions being analysed. Two such rectangular elements are tested on trial problems and consideration is given to efficient determination of a solution. The results support the Finite Element Method as an alternative means of solving the self-adjoint elliptic problem.

Barry, M. W. (1977). Computing in the Printing Industry. Australian Computer Journal 9(1): 39-41.

Printing is one of man's oldest skills, yet one which is still practised most actively - imagine today's world without newspapers, magazines, novels, encyclopedias, directories or catalogues. When Gutenberg invented movable type in the mid-fifteenth century, little did he know that the basic principles he pioneered would remain in common use for five hundred years. Although other communication media such as television and computer displays are making inroads in some areas, the majority of information flow is still via the printed word.

Barter, C. J. (1983). Communications Policy for Composite Processes. Australian Computer Journal 15(1): 9-16.

The paper discusses group composition techniques, and the communications interfaces between processes when they are organised as a group. When a message is sent to a group of processes as a whole, one or more of the component processes may receive it. For each message type and group, a group policy expression determines the disposition of messages within the group, and a notation for group policy expressions is presented. The notation also provides for the encapsulation of one process by another without the use of shared variables. Policy expressions are also shown to provide a measure of control over message sequences, which is useful when specifying extended transactions to transaction processing systems.

Baudet, G. M., Brent, R. P. and Kung, H. T. (1980). Parallel Execution of a Sequence of Tasks on a Asynchronous Multiprocessor. Australian Computer Journal 12(3): 105-112.

Given a sequence of tasks to be performed serially, a parallel algorithm is proposed to accelerate the execution of the tasks on an asynchronous multiprocessor by taking advantage of fluctuations in the execution time of individual tasks. A parallel program requiring no critical section is given to implement the algorithm and its correctness is proved. A spacewise more efficient implementation which requires the use of critical sections is also given. An analysis is presented (for both implementations) to estimate the speed-up achievable with the parallel algorithm, when the execution times are exponentially distributed, and no critical section is used, the algorithm with k processes yields a speed -up of order square-root of k.

Bayes, A. J. (1969). A Network Representation of Serial Code. Australian Computer Journal 1(5): 246-250.

A piece of Fortran code can be represented by a network. The representation is useful in designing a compiler to produce optimised object code. Three examples are given, (1) Optimisation to maximise execution speed in a serial computer, by algebraic manipulation at source code level. (2) Maximising execution speed in a parallel computer. (3) Minimising the number of temporary storage positions required to execute the code. The network can be combined with existing techniques to design an optimising compiler.

Bayes, A. J. (1970). Statistical Techniques for Simulation Models. Australian Computer Journal 2(4): 180-184.

The paper discusses the application of statistical techniques in simulation modelling to estimate the precision of estimates and to increase the precision of estimates for a given run length. Topics discussed are: the effect of the autocorrelation on the precision of estimates; the application of importance sampling in simulation; the changes needed in simulation languages and their compilers to incorporate the techniques. The methods are illustrated with numerical results obtained by applying them to the simulation of a single server queue.

Bayes, A. J. (1973). A Dynamic Programming Algorithm to Optimise Decision Table Code. Australian Computer Journal 5(2): 77-79.

A dynamic programming algorithm is presented which, given a decision table, produces code whose average execution time is a minimum. The algorithm has been coded in Fortran. It solves an eight question decision table in about 18 seconds compute time on a /360 Model 67.

Bayes, A. J. (1975). The Optimum Merging of Accumulating Non-Formatted Data Bases. Australian Computer Journal 7(3): 140-143.

In some enquiry applications using the IBM program STAIRS, data is created on a day-by-day basis, and both old and new data must be available for enquiry. In these circumstances, the daily databases must periodically be merged, to keep the total number of databases low. This paper describes an algorithm for defining the optimum merge strategy, given certain assumptions. Formulae are derived to assist in estimating the computer time required to merge the data bases.

Bayes, A. J., McWhinney, W. and Murry, C. R. (1973). A Program for Process Design and Optimisation. Australian Computer Journal 5(1): 23-28.

This paper describes a program for designing a process plant. The program has the following features: (a) The blocks of the process are specified by Fortran subroutines of very simple structure, (b) The connection between blocks are entered as input data, making the reconfiguration of the plant easy, (c) The program provides a very wide range of solution techniques. A "language" is defined in which the solution algorithm is specified, (d) The program permits parameter estimation from measured stream values. The program is written entirely in Fortran, and is applicable to a wide range of processes.

Beardon, C. E. (1983). Computers and Industrial Relations: The New Zealand Experience. Australian Computer Journal 15(4): 140-144.

To ensure that society receives the maximum benefit we need to study the detailed interaction between the introduction of new technology and social institutions. A detailed examination of the way new technology has been handled by the industrial relations system in New Zealand reveals many attitudes and procedures that give little ground for optimism. It is suggested that professionals need to go beyond a purely passive role in responding to this situation.

Beaumont, W. P. (1982). A Cobol Project Using Minimal Resources. Australian Computer Journal 14(3): 110-114.

Most university graduates in computing science in Australia find employment which involves applications programming in Cobol, so experience in large-scale Cobol programming is of benefit to them. Because this type of programming is far from the mainstream of computing science, and because of their very limited resources, universities cannot always provide such opportunity. This paper describes a project where the time-consuming aspects of project management were automated, allowing a large number of individual projects to be done with minimal staff involvement. Particular attention is given to the manner in which individual problems were allocated and described automatically. The project involved writing an automated library circulation system, and different problems were generated by random selection from a menu of different sub-tasks. Emphasis was placed on systems analysis and description of the project. Students' responses to the project and the problem of assessment are also discussed.

Beaumont, W. P. and Macaskill, J. L. C. (1974). Computer Exercises in Graph Theory with Automatic Marking and Correction. Australian Computer Journal 6(1): 18-25.

This paper is concerned with a set of computer exercises in graph theory and with a program designed to mark and correct the exercises automatically. Emphasis is given to those parts of the exercise and marking program in which the approach is new. The paper starts with an outline of the marking program and a summary of the exercises. Next, selected topics from the exercises are described in more detail and the method of operation of the marking program is considered. This consideration includes detail concerning the checking of students' programming and the reporting of their progress, together with discussion of some of the problems that arose. The paper concludes with an examination of the advantages of using automatic marking of this type and of student reaction to the course. Improvements in services that can be offered by staff when relieved of marking tasks are evaluated.

Beaumont, W. P. and Macaskill, J. L. C. (1975). Studies in the Simulation of Computers. Australian Computer Journal 7(1): 7-11.

The construction and validation of simulation models of computer systems poses problems that vary greatly with the nature of the system being studied. This paper discusses the particular difficulties posed by simulation of a large-scale multiprocessing system and describes methods that have been used to overcome them. The success of these methods is demonstrated by the validation results, which are presented in the paper.

Beckett, P. and Jennings, A. (2002). Towards Nanocomputer Architecture. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Belbin, L. (1987). The Use of Non-Hierarchical Allocation Methods for Clustering Large Sets of Data. Australian Computer Journal 19(1): 32-41.

Requirements for the pattern analysis of increasingly large sets of data have elevated the utility of non-hierarchical methods. While SAHN (hierarchical) techniques are still very much in vogue, they are unable to analyse large sets of data on fast computers, and in many cases represent an inappropriate strategy. A simple allocation algorithm with an enhanced method for representing association is presented and compared with a standard SAHN methodology. Results suggest that non-hierarchical techniques have been under-estimated.

Belbin, L., Marshall, C. and Faith, D. (1983). Representing Relationships by Automatic Assignment of Colour. Australian Computer Journal 15(4).

Principal component analysis, an example of an ordination technique, is applied to the problem of the meaningful allocation of colour to a set of objects. Data consisting of a set of objects defined by a set of attributes may be categorised using numerical taxonomic techniques, however, the display of results of such techniques is uniformly structural in nature. The method proposed enables perception of additional qualities of the data when used with the data alone or in conjunction with other techniques such as cluster analysis. The aim is to assist differentiation of intrinsic qualities by the objective use of colour. An example demonstrates the utility of the technique by exhibiting a correlation of 75% between the intrinsic national characteristics and the derived colour coding.

Bellamy, C. J., Clarke, N., Heale, K., Miller, P. and Treloar, B. (1985). MONET - The Monash University Local Area Network. Australian Computer Journal 17(2): 67-75.

The paper describes the design of a low cost local area network, MONET, developed by the Computer Centre at Monash University to provide connections between computers, terminals and other devices numbering 2,000 or more. MONET provides asynchronous and synchronous interfaces between nodes and devices operating CCITT V.24/V.28 data with modem controls or data only connections using RS232C or RS422. Nodes are connected by 1.5 Mbit/sec CSMA/CD buses, up to a kilometre in length, providing topology aimed at reliability and minimising interruption to service as the network grows. Serial multiplexed data paths provide a means of connecting LANs to form a common network or disjoint networks with a security gateway between them. All addressing is by name to make software on host computers invariant with respect to the network configuration. Control of routine security and channel allocation is fully distributed between the nodes. Network management is aided by a computer program accessing the network through a privileged port.

Bellamy, C. J. and Race, D. (1968). Computers and Medicine. Australian Computer Journal 1(2): 78-81.

The present trend of thinking in the application of computers to hospital and medical practice is towards collection of medical management statistics, the automation of laboratory procedures, the assembly of general administrative information and accounting and payroll procedures. The authors feel that development of this field has now reached a stage when some practical ideas of the type of system to be installed in a hospital can be formulated. It is felt that a centralised system serving several hospitals each of which use a smaller installation for local information handling would achieve an economical but adequate system. The advantages of such a system are: (1) Improvement of collection, retrieval and analysis of medical data leading to increased effectiveness of the doctor and reduced costs of medical record keeping; (2) Intra hospital and inter hospital communication would be improved, delays reduced, bed use improved and clerical costs reduced; (3) Improvement in collection and assessment of management information; (4) Better resource utilisation and planning.

Benedict, C., Bowen, P., Ferguson, C. and Rohde, F. (1997). The Effects of Normalisation on Data Input Satisfaction of Novice End-Users. Australian Computer Journal 29(3): 111-116.

This paper reports the results of an experiment that investigated the effects of different structural characteristics of relational databases have on end-user information satisfaction. The results show that repeating fields and lack of atomicity adversely affect user satisfaction. The results also show that increased fragmentation resulting from higher levels of normalisation significantly improves user satisfaction. Overall results suggest that higher levels of normalisation reduce task complexity when entering data into databases. This reduction in task complexity culminates in greater end-user satisfaction. The study contributes to further development of theories of individual adjustment to information technology in the workplace by alerting organisations and database designers to the effects of structural characteristics of relational databases on data input satisfaction of end-users. These issues are of increasing importance because of growth in end-user design and maintenance of their own databases.

Benke, K. K. and Skinner, D. R. (1987). Segmentation of Visually Similar Textures by Convolution Filtering. Australian Computer Journal 19(3): 134-139.

we describe an approach to texture segmentation designed for the extraction of a textured object from a textured background. The approach assumes that no information is available on the object texture but that a prior analysis of the background texture has been undertaken. The power of the approach is demonstrated on a texture composite for which object extraction and identification is almost impossible by visual inspection.

Benke, K. K. and Skinner, D. R. (1991). A Direct Search Algorithm for Global Optimisation of Multivariate Functions. Australian Computer Journal 23(3): 73-85.

We describe a direct search method for locating the global optimum of a multimodal function. This is an adaptive probabilistic algorithm suitable for any function of many variables subject to arbitrary constraints. The algorithm is based on a simple model for noise reduction and uses an iterative method for averaging random perturbations in the parameter estimates. No prior assumptions are required about the continuity of the search domain, or about the continuity, differentiability and modality of the function. The algorithm is very simple, requiring little preparation and is suitable for application to functions that are non-linear, noisy and of high dimensionality. The performance of the algorithm is demonstrated by a number of numerical examples, including a highly dimensioned problem in pattern recognition.

Bennett, C. (2001). Issues in the Deployment of Digital TV on the Internet. Journal of Research and Practice in Information Technology 33(4): 336-345. First Page.

Bennett, J. M. (1971). Computers and the Visual Arts. Australian Computer Journal 3(4): 171-177.

This article sets out an edited version of the text of a talk given in 1969 and 1970 to students in the department of Fine Arts at Sydney University and to the Victorian Branch of the Australian Computer Society on 23rd September, 1970. The lecture was illustrated with over fifty slides and a film, and was accompanied by demonstrations of holograms, computer plotting, and precision graphics. The text has been edited so that visual material, most of which is available in the references, is not essential for understanding.

Bennett, J. M. (1977). The Australian Computer Society. Australian Computer Journal 9(1): 7-8.

As the Society's foundation President, it is perhaps appropriate for me to begin this short contribution to the tenth anniversary issue of the Australian Computer Journal with some reminiscences of the events which led to its formation.

Bennett, J. M. (1981). A Tale of Two Professions - Civil Engineering and Computing. Australian Computer Journal 13(3): 70-76.

Two of Professor Hawken's interests were the development and public image of engineering as a profession and the analysis of structures. The address is primarily concerned with aspects of these two interests, and their interaction with computing. The role and history of numerical analysis is outlined, as is the development of computing methods used by structural engineers and the effects computers have had on these methods. Project control techniques in engineering construction and large software projects are surveyed. The address concludes with a discussion of the way computing can totally absorb a person's interest.

Bennett, J. M. (1984). Zipf's Law, Structured Programming and Creativity. Australian Computer Journal 16(4): 122-129.

As software projects increase in size, the effort required to implement them increases at a greater rate. The use of higher level languages and adherence to various rules of "good programming practice" appear to help only marginally in reducing the impact of this non-linear effect, and progress can only be made by calling on techniques for managing complexity which have emerged in other fields. Hierarchical structures are discussed with particular reference to software as is the effect which appears to be common to a wide range of human activities, and which is known as Zipf's law. The effects of variation in individual programming skills, the roles of creativity, invention and innovation and lessons to be learned from case studies of past failure are also examined.

Bennett, J. M., Cooley, P. C. and Edward, J. (1968). The Performance of an Integer Programming Algorithm With Test Examples. Australian Computer Journal 1(3): 182-185.

The most widely used algorithms for solving integer programming problems are Gomory or cutting plane methods, and branch and bound methods. This paper discusses cutting plane methods in general, and two branch and bound algorithms. It takes one of these and compares its performance with the performances of several cutting plane methods on a standard set of test problems. The results indicate some important advantages of branch and bound methods for solving integer programming problems.

Bennett, N. W. (1968). ABACUS - A Fast Fortran System For The IBM/360. Australian Computer Journal 1(3): 149-152.

ABACUS is a fast Fortran system for the IBM 360 computer. The U.S.A.S.I. standard Fortran has been implemented without any extensions, to provide a reference point for teaching and programming interchange. A large proportion of the system is devoted to the detection of errors and the production of diagnostics. A simple monitor ensures rapid transition from one job to the next.

Bennett, N. W. and Sanger, P. L. (1973). The Development of the ACL Language and its Implementation ACL-NOVA. Australian Computer Journal 5(3): 105-114.

The development of a one-terminal system ACTIV-8 for the PDP-8 computer is first described. The concepts of the dynamic syntax checking of keyboard input from the terminal and the interruption of stored program execution via the communicate statement are presented. The development of the new conversational language ACL and its implementation as a multi-user conversational interpreter ACL-NOVA is then described. The ACL-NOVA system runs as a stand-alone system and provides a powerful conversational computing facility for many users in a time-sharing environment.

Beresford-Smith, B. and Schroder, H. (1989). Effective Reconfiguration Algorithms in Fault Tolerant Mesh-Connected Networks. Australian Computer Journal 21(2): 79-84.

New algorithms which achieve fault-tolerance through reconfiguration in mesh-connected networks of processors are presented and analysed. Such architectures are of relevant interest in the area of VLSI and WSI, where systolic arrays, instruction systolic arrays and wavefront array processors have been designed to implement a wide range of different algorithms. The reconfiguration algorithms presented aim at guaranteeing cooperation of the surviving elements even after a number of faults. The connection networks on which the reconfiguration algorithms are based consist of local connection only. Thus even for the optimal algorithms there are small clusters of faults that cannot be overcome. The performance of the reconfiguration algorithms can be measured by their probability of getting stuck in a fatal situation, that is they don't find a suitable reconfiguration.

Best, D. J. (1979). Some Easily Programmed Pseudo-Random Normal Generators. Australian Computer Journal 11(2): 60-62.

The virtues of easily programmed algorithms are explained and then, after brief description, a comparison is made of six such algorithms for generating normal deviates. The six algorithms are compared with respect to speed on a CDC 7600 and in terms of the average numbers of random numbers and mathematical functions needed to generate one normal deviate.

Best, P. J., Mohay, G. and Anderson, A. (1997). MIATA: A Machine-Independent Audit Trail Analyser. Australian Computer Journal 29(2): 57-63.

MIATA ia a machine-independent expert system for retrospective audit trail in multi-user computer systems. This paper summarises intrusion methods and the benefits possible from audit trail analysis performed by an expert system. Proar research in this area is outlined. A summary of the current status of the MIATA project is provided, including definition of the normalised audit trail (NAT) record format, summary of intruder profiles used by MIATA's reporting interface, the selection of foreczsting methods and prototype test results.

Biddle, R., Noble, J. and Tempero, E. (2002). Essential Use Cases and Responsibility in Object-Oriented Development. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Biddle, R., Noble, J. and Tempero, E. (2002). Reflections on CRC Cards and OO Design. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Biddle, R., Noble, J. and Tempero, E. (2002). Sokoban: A System Object Case Study. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Bindhammer, T., Gockelmann, R., Marquardt, O., Shottner, M., Wende, M. and Schulthess, P. (2002). Device Driver Programming in a Transactional DSM Operating System. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Bishop, P. F. (2002). Information and Communication Technology and School Leaders. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Blackburn, J. D. (1978). A SNOBOL4 Program to Clean up FORTRAN Source. Australian Computer Journal 10(3).

A computer program written in SNOBOL4 is presented which sequentially renumbers a FORTRAN source program, and improves its legibility.

Blair, A. (1994). Inter-Connection of Software Components in Intelligent Decision Support Systems. Australian Computer Journal 26(1): 11-19.

Intelligent Decision Support Systems (IDSSs) are constructed using software components from areas such as Operations Research, Mathematical Modelling, Simulation, Statistics, Databases and Artificial Intelligence. A major problem in developing these systems is the management of the inter-connection between the software components which comprise the systems. In this paper,an approach is described for effectively inter-connecting heterogeneous software components in IDSSs. The approach uses three special models to model the design of the inter-connection. The three models include the "component model", the "input/output model" and the "component inter-connection model". These three models are used to specify the Intelligent Interface Modules (IIMs) which implement the inter-connection functions. The suitability of this approach is demonstrated using an IDSS which has been constructed using three heterogeneous software components - an Expert System component, a Database component and a 4GL component.

Blatt, J. M. (1975). A Stable Method of Inverse Interpolation. Australian Computer Journal 7(2): 51-57.

The Muller method is modified so as to yield a rapid, yet stable, algorithm for finding a real root of f(x)=0, given two initial values x1 and x2 such that F(x1) and F(x2) have opposite signs.

Boles, W. W. (1999). Recognising 2D Object Contours in 3D Space Using Wavelet Transform. Australian Computer Journal 31(1): 17-26.

A technique is developed to construct a representation describing planar or nearly planar objects in a three-dimensional space, observed by a camera under arbitary orientations. The technique is based upon object contours parameterised by an affine invariant parameter and the dyadic wavelet transform. The role of the wavelet transform is the extraction of multiresolution affine invariant features from the affine invariant contour representation. A dissimilarity function is also developed and used to distinguish among different object representations. This function makes use of the extrema on the representations thus making its computation very efficient. Experimental results show that the performance of the proposed representation is better than that of other existing methods, particularly when objects are corrupted with noise.

Boothroyd, J. (1968). The Symmetric Matrix Eigenproblem - Jacobi's Method Revisited. Australian Computer Journal 1(2): 86-94.

By changing the usual Jacobi formulae and exploiting these in an ingenious manner Rutishauser has evolved a Jacobi algorithm of considerable elegance and precision. This paper discusses the main features of that algorithm and suggests further changes whereby the eigenvalues may be computed with fewer rotations. Other changes designed to yield the roots in order of algebraic magnitude are outlined and both proposals are supported by Algol procedures illustrating the manner in which these changes may be implemented. Detailed results of numerical tests of these procedures are included.

Boothroyd, J. (1970). The QR Algorithm for Symmetric Tridiagonal Matrices Using a Semi-Implicit Shift of Origin. Australian Computer Journal 2(2): 55-60.

The QR Algorithm is now recognised as the most efficient method for computing the eigenvalues of real general matrices. It is also the most effective method for finding all the eigenvalues and eigenvectors of symmetric tridiagonal matrices. Development of the method, since its introduction in 1961, has largely been concerned with improving its speed and attainable precision. The technique of origin shifting is highly effective in improving the rate of convergence though, for some matrices in which the required shift is large compared with some of the matrix elements, this can result in a severe loss of precision. This paper describes a method of origin shifting which minimises the loss of accuracy. The results of comparative tests with other methods are given and an Algol procedure incorporating the method is described in an appendix.

Boothroyd, J. and Hamilton, P. A. (1970). Exactly Reversible Plotter Paths. Australian Computer Journal 2(1): 220-21.

"Mark my footsteps, good my page, Tread thou in them boldly." - how to cause a digital plotter to retrace exactly the path of incremental steps made in moving from one point to another when the movement is made in the opposite direction.

Borthick, A. F., Bowen, P. L., Liu, M. R. and Rohde, F. H. (2001). The Effects of Normalisation on the Ability of Business End-Users to Detect Data Anomalies: An Experimental Evaluation. Journal of Research and Practice in Information Technology 33(3): 239-262. First Page.

With the proliferation of relational database programs for PCs and other platforms, many business end-users are creating,maintaining,and querying their own databases. More importantly, business end-users use the output of these queries as the basis for operational, tactical and strategic decisions. Inaccurate data reduce the expected quality of these decisions. Implementing various input validation controls, including higher levels of normalisation, can reduce the number of data anomalies entering the databases.Even in well-maintained databases, however, data anomalies will still accumulate. To improve the quality of data, databases can be queried periodically to locate and correct anomalies. This paper reports the results of two experiments that investigated the effects of different data structures on business end-users' abilities to detect data anomalies in a relational database. The results demonstrate that both unnormalised and higher levels of normalisation lower the effectiveness and efficiency of queries relative to the first normal form. First normal form databases appear to provide the most effective and efficient data structure for business end-users formulating queries to detect data anomalies.

Boulton, D. M. (1977). High Density Digital Recording on an Audio Recorder. Australian Computer Journal 9(4): 162-168.

By using a novel frequency modulation scheme it has been possible to record digital information reliably on audio cassette tapes using an unmodified audio cassette recorder. The device to be described uses both channels of a stereo recorder and achieves a transmission rate of 1000 9-bit characters per second. The corresponding bit density per channel is 2400bpi. The device has a low cost and is particularly attractive for archiving program and data files.

Braun, T., Chrisment, I., Diot, C., Gagnon, F. and Gautier, L. (1996). ALF/ILP Based Automated Implementation of Distributed Applications. Australian Computer Journal 28(2): 48-54.

This paper describes the design and the prototyping of a compiling tool for the automated implementation of distributed applications.: ALFred. This compiler starts from the formal specification of an application written in ESTEREL, and then integrates end-to-end communication functions tailored to the applications characteristics (described in the specification); it finally produces a high performance implementation.

Brent, R. P. (1987). A Linear Algorithm for Data Compression. Australian Computer Journal 19(2): 64-68.

We describe an efficient algorithm for data compression. The algorithm finds maximal common substrings in the input data using a simple hashing scheme, and repeated substrings are encoded using Huffman coding. Time and space requirements are proportional to the size of the input data. A modification which uses a bounded input buffer is also described. The algorithm is simpler than comparable linear-time algorithms and gives excellent compression ratios on both text and binary files.

Breydon, G. S. (1984). The EDP Auditors Association in Australia. Australian Computer Journal 16(2): 60-62.

This paper provides an overview of the development and role of the EDP Auditors Association (EDPAA) in Australia over the last decade. It outlines the development and content of the Certified Information Systems Auditor (CISA) programme sponsored by the EDPAA and other professional development activities. The relationship of the EDPAA to other professional bodies in the audit, accounting and computing fields is also described including actions to coordinate and develop audit standards, education and academic research in EDP audit.

Briggs, J. R. and Sale, A. H. J. (1989). Fast Fourier Transforms on Multiprocessor Architectures. Australian Computer Journal 21(1): 13-18.

Multiprocessor systems can provide improved performance for many large computations. The Fast Fourier Transform is an example of this class of computation with many important applications. This paper considers several parallel algorithms developed for a multiprocessor architecture with distributed memory. Concurrent algorithms are developed from the Cooley-Tuckey Fast Fourier Transform for hypercube processor network configurations, and from a parallel Good-Thomas Fast Fourier Transform for tree network configurations. Experimental results are presented from the performance evaluation of these fast Fourier Transforms implemented in occam-2 on a transputer network of nine processors.

Broadbent, M., Butler, C., Hansell, A. and Dampney, C. N. G. (1995). Business Value, Quality and Partnerships: Australasian Information Systems Management Issues. Australian Computer Journal 27(1): 17-26.

This paper reports results from the 1992 survey of 100 Australasian Share Guide (ASIG) organisations. Survey findings revealed the pressures of economic and business conditions of the early 1990s, and identified a number of key Information Systems (IS)-related concerns. While investment in technology and systems may have slowed as a result of the current economic climate, business management still have considerable expectations from IS. The top two management issues in the 1992 survey were: gaining business value from current investment in IT, and achieving alignment between business and information strategies. IS executives also indicated strongly that business managers have yet to realise the potential of IT to make a significant contribution to improving client services, did not fully understand the size of the IT investment, and did not believe that IS provided a quality service. Improving these perceptions was regarded as critical for successful performance as an IS manager.

Broadbent, M., Hansell, A., Lloyd, P. and Dampney, C. N. G. (1992). Managing Information Systems in Australia and New Zealand: Requirements for the 1990s. Australian Computer Journal 24(1): 1-11.

Information Systems Managers of over 200 large Australian and New Zealand private and public sector organisations were surveyed in 1990 as part of an ongoing series of studies focusing on information systems needs, processes and priorities. The results of the 1990 study, with a 61% response rate, indicated a considerable growth in end-user processing of data and in the size of information systems groups. Information Systems managers evaluation of the process of the purchase and implementation of software application packages revealed the somewhat unsatisfactory performance of vendors, although participants believed it was still preferable to purchase packages than develop inhouse. The skills levels and requirements of information systems professionals indicated that the biggest 'skills gaps' were in the management and business areas, particularly aligning information and business strategies and the marketing of information services.

Bromley, A. (2001). A Logic MiniTrainer. Journal of Research and Practice in Information Technology 33(4): 325-328. First Page.

Bromley, A. G. (1976). On the Accuracy and Range of Binary Representations of Floating Point Numbers. Australian Computer Journal 8(1): 38-40.

Various representations of floating point numbers are examined for the range and representation accuracy which can be attained. The mean representation error is determined assuming that numbers occurring in physical problems are logarithmically distributed in their most significant digits. It is found that for a given range a base of two provides the best representation error. This is largely due to the ease with which the normalisation bit of the fraction may be hidden to provide an extra bit of accuracy and the relative uniformity of the representation error over the range. Representations which provide improved accuracy over a limited range together with reduced accuracy over an extended range are found to give improved representation error for a useful range of applications. Such a representation which is fairly simple to implement is described.

Bromley, A. G. (1979). Laboratory Experiments with Computer Control Structures. Australian Computer Journal 11(4): 142-150.

LSI modules are described for incorporation in logic trainer equipment to make possible laboratory experiments to familiarise students with digital control structures. Experiments possible with this equipment include the assembly of a simple computer CPU using either conventional or microcoded implementations. These may each be done within a three hour laboratory session by students with some familiarity with digital logic and components but no background in electronics or electrical engineering.

Brookes, C. (1976). The Future of EDP Technology and Impact on Organisations. Australian Computer Journal 8(2): 43-46.

Brookes, C. H. P. (1986). Guidelines for Developing Effective Decision Support Systems. Australian Computer Journal 18(4): 186-190.

All managers face real difficulties in specifying and utilising MIS to help them make effective decisions. In this paper it is proposed that the premises on which many of these MIS designs are based are faulty, resulting in systems which are inflexible, unsuited to individual managerial tasks, unhelpful in assisting the recognition of problems and opportunities, and inadequate in assisting the manager in performing diagnosis and evaluative reasoning. A strategy for the specification of management information systems which are more effective and may truly be called decision support systems is presented. This builds on some of the basic concepts of decision theory and provides an environment which allows systems developers to take advantage of the most recent advances in fourth generation computing software.

Brophy, H. F. (1970). Improving Programming Performance. Australian Computer Journal 2(2): 66-70.

There is relatively little written or discussed about programmers, who represent a large part of the investment in computing. This paper attempts to focus attention on an understanding and evaluation of the programming task, suggesting ways to improve the programmer's lot, and to raise his productivity. It is important to realise that the programmer is involved in human problem solving, and communicating not only with the machine, but with other people. His ultimate product will reflect his creativity, efficiency and ability to communicate. To get more from the programmers, we should provide him with better tools, train him in the use of those tools, and standardise and manage his performance. Several specific ideas and suggestions are given, many of them having been already instituted in a few organisations.

Bukhres, O., Mossman, M. and Morton, S. (1998). Mobile Medical Database Approach for Battlefield Environments. Australian Computer Journal 30(2): 87-95.

With the advent of portable computers and wireless communication systems, much research has been devoted to mobile computing and database query management. The introduction of portable computers into existing database systems requires traditional transaction mechanisms to be adapted to meet the needs of the mobile user. These mobile users utilise hand-held and laptop computers, which are called mobile hosts, that can access the database from any location at any time. Unlike fixed hosts, the mobile hosts can be "disconnected" from the network for long periods of time. Moreover, advancements in cellular and satellite technology have permitted portable computers to communicate with existing distributed computing networks. Users with palm-top computers, known as mobile hosts (MHs), utilise wireless connections to communicate with wired networks from a number of locations at different times. In this paper, we introduce a mobile database approach and an architecture for a medical battlefield environment. When data is stored on mobile hosts, the mobility issue becomes increasingly more complicated. To deal with this issue, we introduce a transaction manager (MTM) that is responsible for all the global transactions created by mobile hosts, which contain a portion of the distributed database. A battlefield is a very unique environment due to the fact that the medical units are susceptible to damage and disconnection from an attack by an enemy force. Prime Time III, which is being supported by the Medical Advanced Technology Management Office, is the operational name for the telemedicine support for the US troop deployment in Bosnia. A distributed patient-soldier database provides patient-soldier medical information in real-time. An application of the patient-soldier database is discussed with respect to transaction management in the medical battlefield environment.

Burke, P. D. (1976). A Case Study in Front-Ending: A Nova 1200 'Front-End' to a CDC 6671 Multiplexor. Australian Computer Journal 8(2): 82-91.

A Data General Nova 1220 mini-computer has been used as a quasi 'front-end' to a 6671 multiplexor serving a CDC 6400 computer system operating under the SCOPE 3.4 operating system with the Intercom 4 time-sharing package. By simulating 16 200 User terminals on a 4800 baud party line to one port of the multiplexor the number of teletype compatible devices handled by the multiplexor has been increased. Apart from savings compared with alternatives such as the purchase of an additional multiplexor the advantages of the approach are to permit higher asynchronous speeds. To provide various special devices with access to the 6400 and to develop local mini-computer and front-end expertise.

Burley, E. S. (1968). Real-Time in Retrospect. Australian Computer Journal 1(3): 137-142.

This article deals with the development and implementation of QANTAM real-time system for the control of Passenger Seat Reservations and Communications Message Switching at Qantas Airways Ltd., Sydney. This system has been operating very satisfactorily for twelve months and the author provides details of the functions performed by the computers and peripheral units, development time involved and plans for future expansion.

Burmeister, O. K. (2000). Applying the ACS Code of Ethics. Journal of Research and Practice in Information Technology 32(2): 107-120. First Page.

The IT professional, unlike professionals in other disciplines, does not have to abide by the strictures of a professional society. In Australia the professional IT association has a Code of Ethics that, while easily accessible, needs clarification to apply it in the real world. Though the ACS code is distinctly Australian in the way it has been formulated, it sits easily within the general tenets espoused by similar associations in other countries. Although cultural issues have influenced the moral philosophy of the ACS code, there are lessons from other countries that apply in the Australian context. Interpreting the code and applying it to one's situation can be facilitated through seeing how others have applied the code and through understanding its underlying tenets. Key Words: code, clients, employers, ethics, profession, public

Burmeister, O. K. (2001). HCI Professionalism: Ethical Concerns in Usability Engineering. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

It has been argued that it is in the best interests of IT professionals, to adopt and enforce professional codes in the work place. Yet applying the Australian Computer Society's Code of Ethics in actual every day situations has been left to individuals. This paper aims to help usability engineers interpret the code. This is achieved by utilising five case studies both directly in terms of the ethical issues involved and in the light of the code. The paper also examines the short-comings of the code in the domain of usability engineering. The paper concludes with suggestions of how the code might be enhanced to better aid the HCI professional in their work.

Burmeister, O. K. (2001). Usability Testing: Revisiting Informed Consent Procedures for Testing Internet Sites. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

This paper explores issues of professional, ethical conduct in usability testing centering around the concept of 'informed consent'. Previous work on informed consent has been in homogeneous geographic locations. With Internet sites being developed at a prodigious rate, these procedures need to be revisited for their applicability to heterogeneous locations, in terms of culture, business practice, language and legal requirements. Some previously valued principles might now be considered discretionary, that is their applicability has situational specificity. Other principles are mandatory.

Burnside, J. W. K. (1990). Copyright and Computer Software - Autodesk Inc v. Dyason and Kelly. Australian Computer Journal 22(4): 140-144.

In 1984 the Commonwealth Parliament amended the Copyright Act by introducing a specific reference to computer programs. Autodesk Inc. v. Dyason and Kelly is the first case in Australia to test the application of the Copyright Act to computer software, since the act was amended. The case raised fundamental questions about the nature of "computer programs" as defined in the Copyright Act, and the nature of the protection given to computer programs. Historically, copyright protection has been granted to the form in which an idea is expressed rather than to the idea itself. The attempt to protect computer programs by including them within the category of "literary works" for the purposes of the Copyright Act, challenges fundamental notions about the application of copyright law, and raises for consideration whether copyright is an appropriate medium for the protection of computer software in any event.

Burr, E. J. (1968). Cluster Sorting with Mixed Character Types, I - Standardization of Character Values. Australian Computer Journal 1(2): 97-99.

When both nominal and metrical characters occur in the same set of data, squared Euclidean distance is a convenient basis for measures of dissimilarity between clusters, provided that a suitable method of standardization is chosen, for both nominal and metrical characters. Examination of the information measure suggests a new method for standardizing nominal characters with three or more states.

Burr, E. J. (1970). Cluster Sorting with Mixed Character Types, II - Fusion Strategies. Australian Computer Journal 2(3): 98-103.

Two new geometrical fusion strategies - increment Sum of Squares, and variance - are introduced and some of their properties derived. Six geometrical strategies and the information statistic are tested on a completely symmetric set of elements, corresponding geometrically to a regular simplex. All except the centroid strategy and information statistic give the "correct" result. In one case the information statistic, although asymptotically correct for large clusters, yields chained reversals.

Burr, J. (1980). Marginal Totals for Multidimensional Arrays. Australian Computer Journal 12(4): 137-139.

Effieient procedures are derived for computing arrays of marginal totals S from any given multidimensional array X, for use when the number of dimensions X or S is unknown at the time of writing the program. Generalized transposition of X is included as a special case.

Burston, A. K. (1984). Logic Synthesis for a Computer Hardware Design Language. Australian Computer Journal 16(4): 130-139.

A logic synthesiser for converting high level descriptions of digital hardware written in a computer hardware description language to an actual logic network is described. The nature of the translation is such that the resulting logic is fast and readily understood for commissioning and maintenance. The synthesiser is placed in the context of a complete logic design system. An example of the translation is given along with figures indicating the performance of the system compared with a hand produced design for the same function.

Busch, P. and Richards, D. (2001). Graphically Defining Articulable Tacit Knowledge. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Busch, P. A., Richards, D. and Dampney, C. N. G. K. (2001). Visual Mapping of Articulable Tacit Knowledge. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Bushell, C. J. (1983). Privacy Versus Policy, Precedent and Expediency. Australian Computer Journal 15(4): 151-153.

The South Australian Cabinet issued a directive to State Government agencies which appeared contrary to the guidelines which assist privacy. The Government then attempted to justify this action on the grounds of policy, precedent and expediency. This paper discusses the case and the position of the ACS in such situations.

Butts, L. and Cockburn, A. (2002). An Evaluation of Mobile Phone Text Input Methods. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Byun, S. and Hong, E. (2000). Increasing Data Availability for Unreliable Mobile Computers. Journal of Research and Practice in Information Technology 32(3/4): 181-199. First Page.

We propose a new replication control scheme for mobile systems. Replicating data at multiple sites could contribute to enhance the availability regarding the distributed data. Replicating data, however, inevitably induces the burden of maintaining replica consistency which requires more complex synchronisation mechanism, especially in the presence of excessive site failures which could lead to global access breakdown. In order for mobile workers to reliably access global replicated databases without global access breakdown, we devised a new scheme called fault-tolerant quorum consensus (FTQC). The main idea behind FTQC is that quorums are allowed to be accessed fault-tolerantly by resilient voting and deferred quorum-update protocols. We enhanced responsiveness of FTQC by dynamic quorum reconfiguration mechanism which minimizes rollbacks. Based on the results of the performance evaluation, we conclude that FTQC schemes outperform the traditional schemes.

Caelli, W. J. (1979). The CODASYL 1978 Data Base Proposals: An Overview and Discussion. Australian Computer Journal 11(2): 48-59.

The recently published Journals of Development of the pertinent CODASYL committees may be seen as containing the latest data base proposals of that organisation. These proposals are an out-growth of the earlier work, particularly from 1969 onwards, in that the data model used is still the network one based upon "record' and CODASYL "set" constructions. A major departure is seen in the adoption of a three schemas approach along the lines suggested by the ANSI/X3/SPARC data base study group as well as in the record "locking" construction for integrity during multiple concurrent update operations. The major changes to previous Journals of Development are noted for schema definition, subschema and data manipulation languages for COBOL and data storage mapping. The proposals are contrasted with more recent work by the ANSI/X3/SPARC group as well as with the developing "co-existence" model and relational data base concepts.

Caelli, W. J. (1985). Privacy and Security in Office Automation Systems. Australian Computer Journal 17(3): 126-130.

This review paper examines current research into systems for the provision of enhanced privacy and security features in office automation systems. Few research papers have been identified on these topics and the overall impression is one of little to no provisions being available for security enforcement in currently available systems. Document ownership, integrity and authenticity are considered as aspects of overall security provisions while access and authorisation control mechanisms are discussed. The parameters affecting security that uniquely identify an office automation system are explained while the legal and ethical considerations in system usage are mentioned. Encryption and computer architecture are seen as key elements in the design of future, secure office automation systems.

Caelli, W. J. (1987). Guidelines for Privacy and Security in Computer Systems. Australian Computer Journal 19(4): 203-205.

With the maturing of the computer industry in the 1980s, the computer professional must now assume that computer and information systems are no longer used or even developed in a secure and safe environment. Into the 1990s the computer professional will be compelled to increasingly consider the privacy, integrity and authenticity problems associated with systems users, workstations, data networks and data bases. These concerns will not only be forthcoming from within the professional associations of computer people themselves but increasingly from society at large, the law, governmental organisations and standards setting bodies. This will impose new codes for professional practice in the overall area of security.

Caelli, W. J. (1988). Electronic Funds Transfer Systems. Australian Computer Journal 20(4): 168-169.

Caelli, W. J., Edmond, D., Knight, E. A. and Tickle, A. B. (1990). Implications of the Tax File Number Legislation for Computer Professionals. Australian Computer Journal 22(1): 11-20.

Schedule 2 of the Privacy Act (Commonwealth) 1988 contains (interim) guidelines concerning the collection, storage, use and security of tax file number information. This paper reviews these guidelines and discusses their implication for computer professionals in the tasks of design implementation and management of information systems containing tax file number information (and therefore which come within the ambit of the legislation). A number of recommendations are included.

Cai, W., Feng, D. and Fulton, R. (2001). A 3D Image Smoothing Method for Dynamic Functional Imaging. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS.

Cameron, D. and Osborn, E. (1982). Security Aspects of a Magnetic Tape Management System. Australian Computer Journal 14(3): 115-116.

a magnetic tape information security system is described as implemented on a Cyber 76, the major host of CSIRONET (the network of the Division of Computing Research). The deficiencies of the original Cyber 76 operating system are outlined, as is the environment is which the new system is embedded. The security system consists of operational procedures, operating system enhancements, and utilities to allow users to nominate security levels of, and control access to, their tape holdings.

Cannon, J. and Havas, G. (1992). Algorithms for Groups. Australian Computer Journal 24(2): 51-60.

Group theory is a particularly fertile field for the design of practical algorithms. Algorithms have been developed across various branches of the subject and they find wide application. Because of its relative maturity, computational group theory may be used to gain insight into the general structure of algebraic algorithms. This paper examines the basic ideas behind some of the more important algorithms for finitely presented groups and permutation groups, and surveys recent developments in these fields.

Cantoni, A. (1971). Improving Transient Response Calculations. Australian Computer Journal 3(4): 156-161.

In the design of systems by classical techniques it is often necessary to evaluate the transient response corresponding to a given frequency response. A method of calculation is described which gives improved accuracy over other methods due to the use of optimal curve fitting to obtain a continuous piecewise linear approximation to the frequency response. The improved accuracy is achieved with only a small increase in computing time and program complexity.

Capon, I. N. (1968). Computing Science Curricula for Australian Universities. Australian Computer Journal 1(3): 130-136.

This paper contains detailed proposals for university courses in computing science. The viewpoint is adopted that course offerings must be coherent and related to the broad structure of computing science, rather than fragmentary offerings of technique. Details are given for a series of units which can be combined to produce graduates in the various sub-specialities of computing while maintaining enough common ground to allow fruitful interchange of ideas. The paper also discusses the use of these units in the context of a four-year honours degree, and in that of a post-graduate diploma.

Capon, I. N. (1969). Fate of Papers Submitted to the 1969 Australian Computer Conference. Australian Computer Journal 1(5): 285-287.

The following notes are intended as an informal report to the members of the Australian Computer Society, following the society's recent conference. They are not intended to be a complete report from the various conference committees, as they concern only one facet of the work, namely the gathering of papers for the technical sessions. The author believes that the figures shown have some interest in themselves, and that a corresponding tabulation for future conferences may show some long term trends. The response to the call for papers issued by the executive committee was very good: a total of 228 submissions was received, excluding enquiries which did not result in at least a statement of intention to submit a paper.

Carrington, D. A. (1986). User Interface Issues in Programming Environments. Australian Computer Journal 18(2): 55-60.

A programming environment is a context in which software is developed. The user interface refers to the interaction between the software developer and the computer and is an important aspect of the programming environment. Technological advances, especially in hardware, are changing the nature of this interface; the current trend is personal workstations. This article reviews some features of modern user interfaces such as bitmap graphics and multiple windows and discusses their consequences.

Casey, L. M. (1980). Distributed Computing and its Competitors. Australian Computer Journal 12(4): 140-145.

With the falling cost of processors and memory modules there has been a rising interest in their interconnection to form larger systems. This paper surveys the factors affecting general performance for the following three architectural options: (i) High speed single' processor. (ii) Multiple processors connected to a common memory. (iii) Multiple computers connected by a high speed (short distance) communication link. Both hardware and software issues are covered.

Casey, L. M. (1981). Decentralised Scheduling. Australian Computer Journal 13(2): 58-63.

Multicomputer systems, including networks, that are going to realise their full potential for fault tolerance combined with cost effectiveness will need to employ decentralised control. In particular scheduling decisions will have to be decentralised decisions. After comparing decentralised scheduling with its alternatives, this paper goes on to survey mechanisms that have been proposed for decentralised scheduling. Details (including some simulation results) are given for a distributed load balancing scheme that employs latest reported status. This scheme minimises bandwidth requirements, while evenly spreading the work load.

Cashin, P. M., Mayson, M. R. and Podmore, R. (1971). LINKNET - A Structure for Computer Representation and Solution of Network Problems. Australian Computer Journal 3(3): 106-113.

LINKNET is an information structure for representing any network of nodes and interconnecting arcs. The structure applies linked lists and enables a list-processing technique for problem solving with networks. The LINKNET structure has provided a concise implementation of algorithms arising in a wide variety of network problem solving, such as power system analysis, game playing programs, minimum cost path finding and the determination of certain trees and meshes in a network.

Cerecke, C. (2002). Repairing Syntax Errors in LR-based Parsers. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Cerone, A. (2002). From Process Algebra to Visual Language. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Cha, S. D. (2000). Pet Formalisms versus Industry-Proven Survivors: Issues on Formal Methods Education. Journal of Research and Practice in Information Technology 32(1): 39-46. First Page.

Formal methods are gaining steady industrial acceptance as a promising approach to developing high quality software. Although educators find it increasingly important to include formal methods in their software engineering curriculum, they face a dilemma: there are too large numbers and diverse flavors of formal methods to cover in a limited time, and little empirical data exists on relative strengths and weaknesses among them. How can we best develop a curriculum on formal methods given several practical constraints? In this paper we describe our approaches, share experiences, and evaluate results. Our goal is to stimulate further discussion among software engineering education communities on how formal methods can be most effectively introduced to current and next generation software engineers.

Chan, C. S. L., Chan, T. K. Y. and Prakash, E. C. (2001). A System for Geographical and Spatial Data Exploration on the Internet. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Chang, D., Dooley, L. and Tuovinen, J. E. (2002). Gestalt Theory in Visual Screen Design - A New Look at an Old Subject. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Chang, Y., Fu, A. M. N. and Yan, H. (2002). A Hierarchical Approach in Multilevel Thresholding Based on Maximum Entropy and Bayes' Formula. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Chang, Y., Fu, A. M. N., Yan, H. and Zhao, M. (2001). Comparison of Five Conditional Probabilities in 2-Level Image Threshold Based on Bayesian Formulation. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Chang, Y.-J., Ruan, S.-J. and Lai, F. (2002). Sentry Tag: An Efficient Filter Scheme for Low Power Cache. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Chaudhuri, P. (1992). Parallel Search Algorithms for Trees and Graphs. Australian Computer Journal 24(2): 61-69.

Tree and graph searching are of fundamental importance, since they form the basis for solving a wide range of other graph theory problems. Parallel algorithms developed for different types of tree and graph searching problems are mainly based on shared memory model of the single-instruction stream, multiple-data stream computer. This computational model may be viewed as a parallel variant of the standard Random Access Machine (RAM) model of sequential computation and is commonly known as parallel-RAM or PRAM in the literature. This paper aims in reviewing the algorithms for tree and graph searching problems on various PRAM models.

Cheek, B. (1980). A Fast and Stable List Sorting Algorithm. Australian Computer Journal 12(2): 64-69.

"QUICKSORT" has wide applicability as a fast exchange sorting technique. The algorithm is not however "stable" with respect to equal keys. The algorithm "LISTSORT" described in this paper is stable but still retains most of the advantages of the "QUICKSORT" method.

Chen, H.-M., Kao, C.-F. and Huang, I.-J. (2002). Analysis of Hardware and Software Approaches to Embedded In-Circuit Emulation of Microprocessors. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Chen, Y.-J., Horng, S.-J., Kao, T.-W. and Tsai, H.-R. (1998). Parallel Algorithm for the Medial Axis Transform of Binary Images. Australian Computer Journal 30(1): 12-19.

The medial axis transform (abbreviated to MAT) represents a region of a digital image as the union of maximal upright squares contained in the region. In this paper, we present an 0(1) step parallel algorithm for the medial axis transform of an nxn binary image on a reconfigurable array of processors (abbreviated to RAP) using 0(n3) processors. Based on the divide-and-conquer technique, we also develop an 0(n/c) step parallel algorithm for the same problem on a RAP using 0(c.n2) processors. Here c is a constant, 1 <= c <= n and n mod c =0.

Chen, Z., Yu, X. and Feng, D. (2001). A Telemedicine System over Internet. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Cheung, K. and Heiser, G. (2002). A Resource Management Framework for Priority-Based Physical-Memory Allocation. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Chmiel, W. F. and Wilson, D. N. (1993). Software Quality Assurance: Now is the Time, Australia. Australian Computer Journal 25(3): 94-97.

This paper reviews the benefits and implications of software quality assurance (SQA) programmes. Despite the accepted benefits, a recent management survey indicates that Australian industry has yet to successfully implement SQA programmes. The paper concludes that Australian industry must begin to implement SQA now if it is to compete internationally.

Cho, S., Lee, J. and Ma, J. (2001). A Meta-Data Update Policy in a Flash Memory File System. Journal of Research and Practice in Information Technology 33(3): 227-238. First Page.

This paper describes a new mechanism for meta-data update in file systems using flash memory. To fulfill flash memory as a stable storage system, one of its main draw-backs, meta-data update, which occupies the majority of write operations, must be reduced.That is,the file system should avoid weaknesses of flash memory, such a limited number of program/erase cycles and its inability of in-place updates. We exploit two types of i-nodes which are allocated in separate flash areas and also introduce a delta logging method to efficiently utilise flash memory space. A trace-driven simulation shows the results that the performance of our system with two workloads is improved in terms of both time and space utilisation.

Chung, H. and Cho, H. (1998). Data Caching with Incremental Update Propagation in Mobile Computing Environments. Australian Computer Journal 30(2): 77-86.

Users of mobile computers will soon have online access to a large number of databases via wireless networks. Because of limited bandwidth, wireless communication is more expensive than wire communication. This implies that caching of frequently accessed data items will be an important technique that will reduce contention on the narrow bandwidth wireless channel. In this paper, we propose a new cache coherency scheme, named CCS-IUP (cache coherency scheme with incremental update propagation), that allows incremental update and use of derived caches. CCS-IUP is novel in the sense that it tries to avoid invalidating cached data; hence, the number of cache misses may be reduced. Furthermore, in CCS-IUP, the server propagates only relevant fractions (increments, of the modifications that affect the cached data, so that it can significantly reduce the amount of data transmission over the wireless network.

Chung, T.-C. and Cho, J.-W. (1988). An And-Parallel Dataflow Model for Logic Programs Based on Mode Prediction. Australian Computer Journal 20(1): 19-26.

Logic programming offers several kinds of parallelism for executing programs. It is natural to associate logic programming with a data flow architecture to cope with the high parallelism. Since the input/output relationships of arguments are not fixed in such programs, run-time support to exploit the AND-parallelism of logic programs in a data flow model requires control of the dynamic token flow, which induces much overhead. In order to remove the run-time reordering of subgoals, that is, to avoid using dynamic arcs, and to exploit AND-parallelism to some extent in a dataflow model, we adopted the method of predicting the dependency relation between subgoals at compile time. Heitherto there has been no evidence that the dataflow model has been successfully employed to exploit AND-parallelism for pure logic programs. In this paper, we propose a model named the "dataflow model for predicted AND-parallelism (DAMPA)" in which dataflow graphs supporting AND-parallelism for logic programs can be produced at compile-time through a refined static data dependency analysis and a graph generation procedure. Although the dataflow graph in the model does not provide optimal AND-parallelism, there is no run-time overhead such as dynamic arcs between the literal nodes and no join operation between the literals. OR- and argument-parallelism are also considered.

Chung, V.-L. and MacDonald, C. S. (2002). The Development of a Distributed Capability System for VLOS. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Churcher, N. and Creek, A. (2001). Building Virtual Worlds with the Big-Bang Model. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Cifuentes, C. and Fitzgerald, A. (1997). Copyright in Shareware Programs Distributed on the Internet. Australian Computer Journal 29(1): 24-30.

The intellectual property of software developers has been protected by copyright since amendments to the Australian Copyright Act in 1984. In the first Australian case to consider copyright in a shareware program distributed on the Internet, the Court held that the Internet service provider OzEmail had infringed Trumpet Software's copyright in Trumpet Winsock 2.OB by arranging for the program and a set of altered data files to be distributed with other software on diskette as a give-away inserted in copies of computer magazines. The implications of this case for software developers, distributors and users are discussed.

Clague, D. J. (1969). Scheduling In Industry, I - Job Shop Scheduling. Australian Computer Journal 1(4): 208-215.

Scheduling, in industry, for a system analogous to that found in a job shop has long been discounted in favour of the more complex techniques required for network scheduling, and these latter techniques have often been applied to the former case. This paper outlines the requirements of an industrial scheduling system, discusses them and then describes their application in a job system of the type defined in Section 2.1. The methods of establishing priorities of jobs in this environment are shown in detail.

Clague, D. J. (1969). Scheduling In Industry, II - Network Scheduling. Australian Computer Journal 1(5): 267-272.

In Part I of this article, we discussed the methods whereby jobs of the type found in job shops could be scheduled to make maximum use of labour and facilities. Here we generalise the techniques applied there to include jobs which must be scheduled by network techniques (i.e. those jobs with distinct contributory steps being carried out concurrently) showing some of the modifications and refinements which must be employed. An outline of criteria for setting priorities is also given.

Clarke, A. P. and Marwood, W. (1984). A Compact Mathematical Function Package. Australian Computer Journal 16(3): 107-114.

A mathematical function evaluation package is presented. The package kernel is the generalised Hypergeometric Function. The use of this kernel is shown to result in a minimal amount of code and yet realise a powerful computer package. The performance of the package in terms of computational accuracy is examined.

Clarke, B. (2002). Corporate Curricula in Schools: Issues and Implementation. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Clarke, B., Czezowski, A. and Strazdins, P. (2002). Implemention Aspects of a SPARC V9 Complete Machine Simulator. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Clarke, R. (1982). Background to Program Generators for Commercial Applications. Australian Computer Journal 14(2): 48-55.

The emergence and key feaatures of program generators are explained. Examples are given of the appearance and use of one particularly advanced product.

Clarke, R. (1982). Teleprocessing Monitors and Program Structure. Australian Computer Journal 14(4): 143-149.

This article discusses teleprocessing monitors, their impact on program structure, and the development of such programs using the DELTA program-generator package.

Clarke, R. (1987). The Computing Professional's Bookshelf. Australian Computer Journal 19(4): 222-223.

In this article Roger Clarke offers us a short list of those books which every information systems practitioner and teacher should have on their bookshelves. He has been assisted in his compilation by many colleagues from Departments around Australia teaching Information Systems.

Clarke, R. (1990). Social Implications of IT - the Professional's Role. Australian Computer Journal 22(2): 27-29.

Clarke, R. (1992). Case Study - Cardomat/Migros - An Open EFT/POS System. Australian Computer Journal 24(1): 25-36.

Electronic Funds Transfer at Point of Sale (EFT/POS) is an application of information technology for which a very bright future has been predicted, but whose growth rate has been subdued. This paper provides a study of a particular approach to EFT/POS which has successfully addressed the factors which have held back progress. Although some aspects of the application may not be transportable due to particular cultural and institutional factors operating in Switzerland, both the technology and the principles are applicable in other countries.

Clarke, R. A. (1985). Impact on Practitioners of the ALRC's Information Privacy Proposals. Australian Computer Journal 17(2): 76-84.

The Australian Law Reform Commission has proposed legislation to regulate information systems in order to protect privacy. Those proposals are summarised and their impact on information professionals assessed.

Clay, H. J. and Williams, W. T. (1981). DOTX: A New Program for the Production of an Ordered Two-way Binary Table. Australian Computer Journal 13(3): 95-96.

After normal and inverse classification of a binary data matrix, it is often desired to combine the two classifications into a "two-way table" which may then be ordered so that the most dense cells are toward the top left-hand corner. A new program DOTX, is now available which, given the data-matrix and classificatory information, carries out the complete procedure.

Cock, G. L. (1980). Computer Aided Design of Printed Circuit Board Layouts. Australian Computer Journal 12(4).

A large percentage of equipment manufactured for industrial and home use containing electronic equipment includes printed circuit boards (PCBs) on which miniature electronic components are mounted. Computer aided layout methods have been developed which avoid the laborious and time-comsuming manual steps that have been necessary to produce these boards and at the same time allow the use of more accurate and more relable production techniques. This paper describes a computer program that will automatically route wiring paths for printed circuit boards. Conductor path determination is a major step in the production of artwork for PCB manufacture.

Cockburn, A., Bell, T. and McKenzie, B. (2001). Death to the Office of the Nineties: An HCI Perspective on Some Problems in Modern Office Information Systems. Journal of Research and Practice in Information Technology 33(1): 68-82. First Page.

There is powerful evidence that office information systems and the information technology revolution are failing to deliver the expected productivity gains. Increased use of user-centred design and the associated methods and techniques of human-computer interaction (HCI) promise to improve on this poor performance. This paper demonstrates how empirical studies can help in understanding the use and efficiency issues of systems within the modern office. Three case studies examine usability problems that arise from different sources. Firstly, a study of the usability of differing email formats shows that the actions of one user can impact on the efficiency of many other users. Secondly, a study of the use of web page bookmarks shows that, even with effective tools, users can create information management problems for themselves. Thirdly, a study of next-generation 3D systems for file and document management shows that the temptations of technology can confuse both designers and users in striving for more efficient tools. Throughout the case studies we illuminate some of the conflicting issues and factors that make HCI a deeply challenging and rewarding area of research.

Cohen, B. L. and Sammut, C. A. (1978). CONFUCIUS: A Structural Concept Learning System. Australian Computer Journal 10(4): 138-144.

This paper describes a general structural object recognition and learning system. It introduces CODE, a structural description language based on boolean logic and set theory. Internal machine representations of concepts and objects are given for these which directly influence the efficiency of the system. In particular, a data structure called "graft", is described. Two concept learning strategies, LS1 and LS2, used in CONFUCIUS are also discussed. Both algorithms are generalisations of the "Conservative Focusing Strategy" developed by Bruner et al. The generalisations consist of using the high level language, CODE and the introduction of an "implication net" which enables CONFUCIUS to work in a more complex environment.

Coldwell, J. (2001). It is possible to teach computer ethics via distance education!. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

The Australian Computer Society (ACS) has mandated, through their core body of knowledge, that computer ethics and professional responsibility should be included in information technology study programmes. However, quite naturally, the ACS do not provide any direction as to how such content should be imparted to students. Many different models are used to good effect. In this paper I describe the framework in which computer ethics is taught in the Bachelor of Computing at Deakin University. This programme is offered in both on- and off-campus mode. I will discuss the innovations that have been incorporated to accommodate the special requirements of distance education students and demonstrate that it is possible to teach computer ethics without face-to-face contact with students.

Coldwell, J. and Wrightson, G. (1998). Analytic Tableaux and Model Elimination. Australian Computer Journal 30(1): 1-11.

That there exist relationships between Model Elimination and Analytic Tableaux has been known for some time. However, the mapping between these procedures has not been shown explicitly to date. In order to define the mapping between the procedures, we need to use two reduction techniques which avoid the generation of duplicate subtrees in tableaux. By identifying the parallels between the ywo procedures, we have been able to develop a technique so that lemmas can be produced as a side-effect of closing branches within the tableau. Further, we have developed a control structure for Model Elimination which bears many similarities to that used for analytic tableau.

Coldwell, R. A. (1987). Non-Professional Practices in Computing: Some Thoughts on the Next Decade or so. Australian Computer Journal 19(4): 215-218.

Computer crime is a favourite topic of newspaper editors but receives little serious attention from professionals or researchers. Information concerning the perpetrators of computer crime, their targets, modus operandi and motivation is scarce. The potential that exists for professionally organised and targeted computer crime has almost never been discussed in the literature. This paper identifies what is known and speculates on business, and might well be used to wield tremendous political power.

Coldwell, R. A. (1990). Some Social Parameters of Computer Crime. Australian Computer Journal 22(2): 43-46.

The general public rates hacking as of similar significance to minor car-related offences. This anomaly generated the exploratory study, reported in this paper, which probed the responses of tertiary students of different disciplines towards hacking and relates these to their ethical standpoints. It finds that relatively few science students regard hacking as criminal and, moreover, that those in the physical sciences are even less concerned about it than their contemporaries in the life sciences. wE conclude athat, although some tertiary courses inm computer science include modules on professional ethics, undergraduates who choose machine-related disciplines may be considerably less concerned in general, about the social consequences of their work than others who choose to work with people.

Collier, P. A. (1986). Simple Compiler Correctness - A Tutorial on the Algebraic Approach. Australian Computer Journal 18(3): 128-135.

A well motivated introduction to compiler correctness using algebraic methods is presented, with emphasis placed on the intuitive notions underlying the algebraic concepts.

Colomb, R. M. (1985). Use of Superimposed Code Words for Partial Match Data Retrieval. Australian Computer Journal 17(4): 181-188.

Superimposed coding is examined as a practical method of partial match data retrieval. Its computation cost and performance under differing information content of search keys is compared with multi-level indexing and hashing techniques. The conclusion is that the small size of index makes it superior for up to about 10,000 records, and that when augmented with a hashing scheme, it is comparable to multilevel indexing for up to 100,000 records. In addition, the small size of the index makes it practical in many cases to index a disk based file from entirely within memory.

Colomb, R. M. (1988). Table Searching Using a Content-Addressable Memory. Australian Computer Journal 20(3): 105-112.

Recent advances in computer hardware have made it possible to perform simple operations on very long bit strings at high speed, thus implementing word parallel bit serial content addressable memory. It becomes possible to perform search operations on tables using bit maps, which are bit strings containing one bit per table entry. This paper shows algorithms for performing various kinds of table searching, including such complex ones as greater than/less than/equal split, proximity search find minimum and a linear time sort, as well as retrieval of spatial information using quadtree indexing and other applications.

Colomb, R. M. (1993). Use of a Personal Workstation to Access Open Network Services. Australian Computer Journal 25(1): 7-13.

Imagine that people have powerful, flexible workstations which can adapt to their work habits, and that they use an open distributed computing environment for information and computing resources. I argue that the user should have a uniform and seamless view of the computing environment. In addition, the user has a large investment in wordprocessors, spreadsheets and other personal productivity tools. It becomes natural then to argue that the network applications should interact with the user employing the user's personal productivity tools. We need to develop an abstract view of the capabilities of a User Interface Management System (UIMS), which is at a much higher level than graphics interface standards like X11, and also standards for the communication of documentation from an application to a UIMS. There must be standards for sharing models of data structures and definitions of the semantics of their various components. This paper sketches some requirements for the solution of these problems, based partly on data base technology and the design of persistent programming languages and access procedures for persistent object stores.

Colomb, R. M. and Jayasooriah (1986). A Clause Indexing system for PROLOG based on Superimposed Coding. Australian Computer Journal 18(1): 18-25.

Superimposed coding, a general method of partial match data retrieval, is adapted to give a general solution to the Prolog clause indexing problem. Two implementations are described, one using a conventional computer and the other using a special purpose attached processor for performing the calculations needed. The conventional implementation is superior to other proposed methods, while with the attached processor, the indexing scheme becomes effectively an associative memory.

Colvin, R., Hayes, I., Hemer, D. and Strooper, P. (2002). Translating Refined Logic Programs to Mercury. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Conmy, P. and McDermid, J. A. (2001). High Level Failure Analysis for Integrated Modular Avionics. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

Integrated Modular Avionics (IMA) is the term used for a common computer network aboard an aircraft. In order to gain full benefit from this technology a strategy is required to allow the separate development and safety analysis of applications and the computing platform. This paper presents the results of high level failure analysis of an IMA computing platform as a separate system and shows how the analysis can be used as part of an overall certification strategy for IMA. For the analysis six high level functions were constructed which described the functionality provided to applications and devices using the IMA platform. Lower level IMA services, such as scheduling and communications, are used to meet one or more of the functions. Deviations in service provision were considered using a number of guide words to suggest possible failure modes. The analysis revealed a number of weaknesses in the design which will require further consideration.

Connaughton, C. and Dampney, C. N. G. (1994). Surviving Paradigm Shifts in Software Development Technology: A Management Case Study of Industrial Experience. Australian Computer Journal 26(4): 114-123.

The case study of industrial experience concerns the evolution of project management methods to cope with changes in development methods. In the projects studied the technical problems which emerged were, in many respects, the most tractable of the issues encountered. Adopting new development methods certainly introduced additional problems, but it was managing the change in project management needed that was the real challenge. As it turned out, the changes required for the development approach were sufficient to require shifting the mind set - which we can now recognise was a paradigm shift. That is, the establishment development methodology was replaced by a new approach requiring new ways of thinking. The essential result from the case studies, and insights from other fields, is that project management concerns in the development process are distinct and must be separated from the technical issues of development method.

Connelly, S., Burmeister, J., MacDonald, A. and Hussey, A. (2001). Extending and Evaluating a Pattern Language for Safety-Critical User Interfaces. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

This paper describes the extension and evaluation of an existing pattern language for safety-critical user interface development. The patterns were updated and new patterns were added by examining existing medical systems. The new patterns were found by generating problem definitions from perceived exemplary solutions. This method of pattern development and its application is described. A qualitative evaluation of the pattern language was performed by designing a safety-critical user interface for a hypothetical radiation therapy machine. Discussion of the design process focuses on the usefulness of our patterns as a design tool for safety-critical user interfaces.

Cook, B. G. (1967). A Computer Representation of Plane Region Boundaries. Australian Computer Journal 1(1): 44-50.

A data structure for the storage of representations of plane region boundaries is described which attempts to exhibit their pictorial structure. The reasons fore adopting this representation are discuss in some detail.

Cook, B. G. (1986). Recording the Computational History of a Research Project. Australian Computer Journal 18(2): 81-86.

In research projects with substantial computational requirements, it is important that a detailed and accurate record be maintained to enable a thorough audit of any part of the conclusion-reaching process. The paper discusses the documentation needs of such projects and describes a prototype project control system which has been used to automatically document the computations of a long-term natural resources research project.

Cook, G. C. and Mayo, K. K. (1977). A Geographic Data Base Using FORDATA. Australian Computer Journal 9(4).

The paper describes the design, establishment and use of a geographic data base using the FORDATA data base management package. The database, established as a research tool in a land use planning study, has been in continuous use for two years.

Coomber, C. J. and Horan, P. (1995). A New Method for Converting Trace Theoretic Specifications to Signal Transition Graphs. Australian Computer Journal 27(2): 62-70.

The specification of delay-insensitive, asynchronous circuits can be undertaken in a variety of ways. Two methods discussed in this paper involve Trace Theory and Signal Transition Graphs. Trace Theory is used to describe the behaviour of circuits in terms of sequences (or traces) of signals. These traces can be composed to express cooperative behaviour. However, the resultant composite often suffers from on explosion of states and transitions, which make it difficult to visualise synchronous and concurrent behaviour. By employing Signal Transition Graphs, which are a kind of Petri net, this problem can be ameliorated. In this paper we summarise both Trace Theory and Special Transition Graphs and describe the advantages we have found in using both interchangeably. The bulk of the paper is devoted to a new technique we have devised for converting Trace Diagrams into Signal Transition Graphs. This technique allows us to readily exploit the benefits of both Trace Theory and Signal Transition Graphs.

Coombes, R. L. (1976). Comprehensive EDP Security Guidelines. Australian Computer Journal 8(1): 25-37.

These guidelines on Security within the EDP environment are produced as a result of meetings of ACS N.S.W. Branch Software Security Special Interest Group. This group was originally formed under the Chairmanship of R.M. Faulkner in 1973, and later revived under its present Chairman R.L. Coombes in 1974. This publication is recognised by the ACS N.S.W. Branch and ACS National Council as an exposure draft which does not necessarily reflect the views of either body. However it is envisaged that when members have considered, criticised and commented on the publication both bodies will then consider endorsing an amended document to reflect the original attitude of the Australian Computer Society Incorporated.

Coote, A. (1972). Apportioning and Rounding. Australian Computer Journal 4(1): 40-41.

A simple method of handling the common commercial task of apportioning figures on a rounded basis is described in non-mathematical terms and illustrated by means of a PL/I program.

Coote, A. (1979). Apportioning on a Working Day Basis. Australian Computer Journal 11(1): 29-34.

A simple method of handling the common budgeting task of apportioning figures over a 12 month period on a working day (or similar) basis is described and illustrated by means of a "structured" COBOL program.

Cottingham, M. S. (1989). Interpolative Hidden Surface Removal Method for Polyhedra. Australian Computer Journal 21(3): 67-70.

All hidden surface removal methods involve sorting facets into some order. This can be time consuming when thousands of facets are involved. These facets can then be processed in different ways. They can be rendered in depth order which requires a lot of drawing time. They can be subdivided into visible and invisible sub-facets with only visible parts being rendered, which requires less drawing time but some time is required for subdividing facets. The image space can be subdivided and the relevant parts of visible facets drawn in each area, but again subdivision takes time. This paper introduces an alternative approach which increases efficiency by ordering at the object level rather than at the facet level. It assumes that facets are stored in a data structure that enables adjoining facets to be easily accessed and uses 'adjoining coherence' to deduce active facets. It utilises interpolation methods for calculating depth values of potentially visible facets.

Craig, M. D. and Green, A. A. (1987). Registration of Distorted Images from Airborne Scanners. Australian Computer Journal 19(3): 148-153.

This paper presents a solution to the problem of co-registering images, one or more of which was acquired by an airborne scanner system. Globally defined transformations of coordinates (e.g. high-order polynomials) may fail to account for the complex, local distortions found within such imagery. But simple, linear transformations suffice, provided the scene is first partitioned into subregions on a scale finer than the distortions. Appropriate software permits large numbers of tie-points to be collected with relative ease. A new algorithm is presented for computing the associated Dirichlet tessellation, which is used in deriving the Delone triangulation. A grey-level-coded image of triangles, in register with the output grid, serves to guide the resampling program at each point in the correct set of pre-computed transformation coefficients, this being the set for the linear mapping based on the vertices of the encompassing triangle.

Cramp, A. and Oudshoorn, M. J. (2002). Employing Hierarchical Federation Communities in the Virtual Ship Architecture. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Crehan, A. C. (2001). Mabo-Style Claims to the Radio Spectrum. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

My concern in this paper is going to be the ways in which various Information Technology (IT) developments can raise ethical issues in seemingly unrelated (ie. non-IT) areas. In particular, I want to show how developments in relation to the Radio Spectrum raise ethical issues about the rights which indigenous Australians have qua indigenous Australians. Along the way, I will illustrate the limits of contemporary Australian approaches to the concept of native rights, and raise the question of whether alternative approaches ought to be preferred.

Croft, B. (2002). The Future of Web Search. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS.

Crossley, J. N., Lim, P. and Stuckey, P. (1989). Interface Logic Programming. Australian Computer Journal 21(2): 49-55.

The Constraint Logic Programming (CLP) scheme generalises the model-theoretic and operational models of logic programming to include constraints over particular problem domains (structures). Languages in the CLP scheme are operationally similar to PROLOG and hence their implementation problems are similar indeed most instances of the CLP scheme contain PROLOG since they use uninterpreted functors for data structures. As this common framework underlies instances of the CLP scheme, a great deal of the implementation of different CLP languages can be contained within a single generic (with respect to structure) implementation. To this end an interface Logic Programming system (ILP) has been produced. Code for each CLP language now requires only the implementation of a solver for the particular structure. The ILP system provides the remaining elements of the language. This significantly reduces the time required to produce new implementations of CLP languages. We have implemented an ILP system and used it to produce a CLP instance in the domain of uninterpreted functors over a free Boolean algebra. CLP(B). This domain was chosen because of its interesting applications in circuit design and other areas. The Boolean constraints allow sound form of negation and provide mechanisms for hypothetical reasoning and default reasoning.

Dale, M. B., Lance, G. N. and Albrecht, L. (1971). Extensions of Information Analysis. Australian Computer Journal 3(1): 29-34.

The polythetic agglomerative method of Information Analysis has proved a useful technique of numerical classification. In this paper, some extensions of the method which permit certain types of quantitative data to be analysed are presented. In addition, consideration is given to some methods of constraining an analysis and to the introduction of weighting based on the topographic distribution of the operational taxonomic units. Details are given of the programmes available to perform such analyses.

Dale, M. B., MacNaughton-Smith, P., Williams, W. T. and Lance, G. N. (1970). Numerical Classification of Sequences. Australian Computer Journal 2(1): 9-13.

The problem of classifying sequential data is reviewed, and a new information-statistic method is described, applicable when the sequences can be treated as homogeneous Markov processes. The elements actually classified are single step transition matrices; two numerical models are available, one of which fails if the matrices contain all zero rows. The system can be extended for use in dissimilarity or canonical procedures. A brief specification is provided of the program TRANSMAT for the Control Data 3600 computer.

Davenport, R. A. (1978). Data Analysis for Database Design. Australian Computer Journal 10(4): 122-137.

The primary purpose of data analysis is to determine the fundamental nature of an organisation's data resources and to organise and document all relevant facts concerning this data. This paper describes a methodology for data analysis which has been applied in a number of actual situations and has been found to provide a very effective means of communication with users and a sound basis for the subsequent database design. The methodology employed is based on representing the environment in terms of entities and their attributes and relationships. The methodology when used in preparation for database design, involves two distinct phases - entity analysis and functional analysis. The inherent nature of the environment and its representation in the form of data, is analysed distinctly (though not independently) from an analysis of the business activities and the ways in which data is employed.

Davenport, R. A. (1979). Logical Database Design - From Entity Model to DBMS Structure. Australian Computer Journal 11(3): 82-97.

Logical database design is the process of mapping the information structure of an organisation into a structure acceptable by a specific database management system to produce a logical database structure. This paper describes a methodology for logical database design which takes into account not only the structuring limitations of the database system but also the effect of design objectives. As an example the methodology is applied to an environment to produce a logical database structure for the TOTAL database management system.

Davoren, A. G. (1972). Effective Programming. Australian Computer Journal 4(3): 112-119.

This paper examines the functions involved in programming. It establishes criteria for effective programming and offers suggestions as to how the criteria may be satisfied. Program testing time is shown to be the significant area for improvement.

Day, J. D. and Kambayashi, Y. (1977). Stability of Serial Hybrid Computer Solution of Linear Parabolic Partial Differential Equations. Australian Computer Journal 9(2): 77-79.

The well known Serial or Continuous Space Discrete (C.S.D.T.) method of solving linear parabolic partial differential equations on a hybrid computer encounters serious error growth problems in both space and time. A method of analysing these instabilities by matrix calculus is described.

de Ferranti, B. and Deane, J. (2001). Early Contributions to IT in Australia from the Basser Department of Computer Science - John Bennett's SILLIAC years. Journal of Research and Practice in Information Technology 33(4): 280-293. First Page.

De Silva, C. J. S., Choong, P. L. and Attikiouzel, Y. (1994). Artificial Neural Networks and Breast Cancer Prognosis. Australian Computer Journal 26(3): 78-81.

The paper describes the application of Artificial Neural Networks (AANs) in the prediction of disease-free survival time of breast cancer patients. A brief introduction to ANNs, which contrasts them with conventional computers, is given. The problem of prognosis in breast cancer is then outlined. The techniques used to predict disease-free survival time using the Multi-Layer Perceptron are described, and results on a particular set of patient data are presented.

De Silva, R., Dairaine, L., Seneviratne, A. and Fry, M. (1996). A Comparison of Automatic Protocol Generation Techniques. Australian Computer Journal 28(2): 55-60.

Due to the increasing complexity of applications and the availability of high speed networks, classical protocols have become the main bottleneck in communication systems. Although tailored protocols are able to respond to the needs of a given application, their development is expensive in terms of time and effort. An automatic protocol generation environment is most desirable. Two approaches currently used are the sub compilation and the runtime adaptive techniques. We have studied these two approaches and the behaviour of the resulting tailored transport protocols. Relative performance comparisons and discussions about these two approaches are presented in this paper.

Debenham, J. K. (1972). Lemma Production with a Binary Resolution Based Theorem-Prover. Australian Computer Journal 4(3): 120-126.

In a binary resolution based theorem proving system functions are introduced to evaluate:- (i) the resolvability of a clause (ii) the distance of a clause from a set of clauses, and (iii) the cost of obtaining a clause. Using these functions it is shown that simple strategies for selecting lemmas may be defined. Various examples from the current literature are quoted to illustrate the application of this method of lemma production to theorem proving problems.

Debenham, J. K. (1985). Knowledge Base Design. Australian Computer Journal 17(1): 42-48.

Some of the major problems in designing knowledge bases and in implementing knowledge bases in logic are discussed. Essential and desirable features of design techniques are noted. A simple case study is used to introduce an approach to knowledge base design.

Debenham, J. K. and McGarth, G. M. (1983). LOFE: A Language for Virtual Relational Data Base. Australian Computer Journal 15(1): 2-8.

A powerful query language for virtual relational data base is described. It is shown that this language has a natural restriction which serves the needs of the low level user.

Deighton, D. M. (1977). Computers in Operations Research. Australian Computer Journal 9(1): 17-20.

Workers in Operations Research (OR) have benefited from most of the advances in computer technology which emerged during the last decade. The paper discusses some of the important ways in which advances such as bigger, faster computers, improved software, multiprocessing and specialised languages have been of assistance. The improved access to data which arose from the increased number of automated information systems and from data transmission has also been of benefit. The impact on OR work of prospective changes in computer technology is expected to be less than, or at least different from, that of changes which occurred during the past decade.

Dekker, A. (2001). Visualisation of Social Networks Using CAVALIER. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Deng, D. D. S. and ElGindy, H. (2002). High-speed Parameterisable Hough Transform Using Reconfigurable Hardware. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Dengate, G., Couger, J. D. and Weber, R. (1990). Motivational Characteristics of Australian Information Systems Personnel. Australian Computer Journal 22(3): 77-87.

Effective human resources management within the information systems (IS) industry has been undermined by two endemic problems. First, widespread shortages of IS personnel exist. Second, employee turnover within the IS industry has been high. To alleviate the effects of these problems management must attempt to ensure that IS personnel are committed, motivated, and satisfied with their current positions and career prospects. To provide a basis for improving the management of IS personnel, a survey of Australian IS professionals was conducted to determine their attitudes toward their jobs and their individual growth needs and social needs. The results obtained were compared with those obtained for IS professionals in the US and Singapore.

Deray, K. (2002). Avatars: A Shifting Interaction. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Dew, R. A. (1992). Determining Maximal Subsets of Enabled Transitions when Simultaneous Conflict Occurs in Petri Nets. Australian Computer Journal 24(3): 152-161.

There are two general strategies for firing transitions of a Petri net. In the first, one enabled transition is selected and fired. This firing produces a Petri net marking which enables another set of transitions. Execution continues by selecting and firing a transition from this new set of enabled transitions. In the second execution strategy all enabled transitions are fired simultaneously, whereby a marking is produced which enables another set of transitions. Execution continues by firing all enabled transitions of this new set. Sometimes, all enabled transitions cannot fire simultaneously because some transitions, when fired, disable other enabled transitions. This is called simultaneous conflict. At simultaneous conflict, in which many transitions are enabled, it is possible to fire any one transition. Furthermore, it is possible to fire one of many subsets of enabled transitions. Of interest are the maximal subsets of enabled transitions. The property of such a subset is that all transitions in the subset can fire simultaneously. In this paper an algorithm to determine all such maximal subsets when simultaneous conflict occurs is described.

Diaconescu, R. E. (2002). Distributed Component Architecture for Scientific Applications. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Diebold, B. and Kaufmann, M. (2001). Usage-based Visualization of Web Locations. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Donohoo, A. and Richards, D. (2002). Layered Earth Inversion Visual Toolkit: A Scientific Visualisation Case Study. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Doran, R. W. (1972). A Computer Organisation with an Explicitly Tree-Structured Machine Language. Australian Computer Journal 4(1): 21-30.

An outline is given of the organisation of a simulated computer which has a tree structured machine language. The structure of programming languages is discussed with regard to the choice of relevant machine language. A mnemonic notation for expressing machine language programs is introduced and the computer (tree machine) which incorporates and extends the addressing techniques of stack machines, is then outlined. To emphasise how close the machine language is to a high level language, a free field assembly language is also introduced. The tree machine is then described in more detail.

Dowling, C. (1999). Minding Our Manners: Public and Private Disclosure Within Electronic Environments. Australian Computer Journal 31(3): 89-93.

With an increasing number of our interpersonal inter-actions both within and outside the workplace taking place online, there is urgent need for a better understanding of the way in which certain qualities of the electronic medium effect communication, particularly in relation to traditional expectations regarding 'good manners'. Evidence suggests that people's verbal behaviour within electronically mediated environments often differs significantly from that which they exhibit in face to face situations. At the same time we should be alert to recognise the nature of any changes to our understanding of acceptable ways of interacting through the written word which are already taking place.

Dowling, C. (2001). Intelligent Agents: Some Ethical Issues and Dilemmas. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Not so long ago, intelligent software agents belonged in the realms of speculation and esoteric research. Today, like it or not, they are an important part of our everyday lives online. Characteristics commonly acknowledged as desirable include a degree of anthropomorphism or personification, the ability to learn from experience and consequently to respond flexibly to new situations, the capacity to interact both with users and with other agents, and a significant measure of autonomy in the pursuit of goals. The widespread implementation of agent based systems raises a number of issues that have clear ethical, even moral dimensions. While the image of an 'agent' may suggest that the technology is under the control of the user, the metaphor is less straightforward than it appears, and the confidence and security it engenders may sometimes be misplaced. Implicit in our understanding of the concept of agency is the notion of delegation. Important ethical aspects of this concept include the balance between autonomy and control, and questions related to trust, responsibility and privacy. While the 'usefulness' of agents in achieving certain outcomes is undeniable, this utility perhaps comes at a certain cost that we may or may not consider acceptable. Through consideration of our experiences of agents both in the physical world and online, this paper explores some of the ethical issues arising from the widespread implementation of intelligent agents within computer based environments.

Dowrick, P. W. (1975). Comparing Computer Usage: A Case Study. Australian Computer Journal 7(1): 12-14.

Manufacturer-supplied timings are too complex to provide a real basis for comparison among data processors. Empirical studies must be performed. There are pitfalls here too, and the consumer must be alive to them. A small scale example is given here in some detail.

Drake, R. W. and Smith, J. L. (1971). Some Techniques for File Recovery. Australian Computer Journal 3(4): 162-170.

As the scope and complexity of computer use grows so the necessity to guarantee the integrity of files in the face of all software and hardware failures becomes more critical. The cost of the potential information loss from particular failures justifies a large investment in recovery procedures which will reproduce files from redundancy designed into the system. The goals of these recovery procedures vary with the size and importance of the files concerned.

Dromey, R. G. (1979). A Fast Algorithm for Text Comparison. Australian Computer Journal 11(2): 63-67.

Two new algorithms for finding the longest unbroken common subsequence in a pair of text files are presented. The algorithms are simple to implement, economical on space requirements and they are highly efficient for comparison of pairs of text files for all ranges of overlap both large and small. For example, it was necessary to make only 1429 comparisons to establish that the largest common overlap between two files of 1024 characters was 26 characters. Larger overlaps require even fewer comparisons.

Duke, D. (2001). Modular Techniques in Information Visualization. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Duke, R., Johnston, D. and Rose, G. A. (1987). Specifying the Static Semantics of Block Structural Languages. Australian Computer Journal 19(2): 99-104.

In this paper we look at how the static semantics of a block structured programming language can be formally specified. These ideas are then illustrated by giving a complete formal specification of the static semantics of a small language using the Z specification notation. Our formal specification of static semantics will deliberately ignore any problems involved in implementing error recovery for the language. Consequently, the specification is short and direct and gives the language user precise rules to follow when creating programs with correct static semantics.

Duke, R. and Smith, G. (1989). Temporal Logic and Z specifications,. Australian Computer Journal 21(2): 62-66.

The Z specification language can be used to capture liveness properties of state transition systems such as those used to specify communications protocols. The specification of such systems involve temporal concepts such as "eventually" and "always". In this paper we extend standard Z to include the temporal logic operators so as to provide a powerful notation for discussing the liveness of state transition systems. By way of illustration of the ideas involved, we look at a state transition model for an alternating bit protocol, and compare the specifications of liveness in standard Z and Z enhanced with the temporal logic notation.

Dunstan, N., Keedy, J. L. and Rosenberg, J. (1993). Support for Concurrent Programming on the MONADS-PC System. Australian Computer Journal 25(1): 1-6.

To support concurrent programming the MONADS-PC instruction set and operating system kernel provide facilities for process creation, synchronisation and scheduling. These facilities are assimilated with the LEIBNIZ programming environment, appearing as module class definitions. They form a small and efficient set of primitives which, when utilised by the modular features of the LEIBNIZ programming language, allow software modules to be constructed to support concurrent programming in a variety of styles. Modules supporting some of the more common styles are described. In addition, the MONADS-PC System's persistent, capability-based programming environment provides some new and very useful possibilities for concurrent programming.

Dwyer, B. (1982). Cobol, Comments and Correctness. Australian Computer Journal 14(2): 42-47.

A tutorial introduction to 'disciplined programming', with suggestions for its use in a COBOL programming environment.

Dwyer, B. (1985). Should Cobol Support Coroutines. Australian Computer Journal 17(2): 62-66.

Coroutines provide a means of structuring programs to express solutions to many application problems in a natural way. ANS Cobol so nearly supports their use that minor changes to the standard would permit them, and make the language more useful.

Dwyer, B. (1986). Kay: A Beginner's Environment. Australian Computer Journal 18(2): 75-80.

Kay is a complete programming environment, designed to teach raw beginners the principles of structured programming. It is an interesting experiment in applying 'learning theory'-specifically 'operant conditioning'. An interactive computer environment is a potent modifier of behaviour. Kay's responses have been designed to emphasise reward rather than punishment, so that is provides a pleasant environment. The same approach could be applied to larger systems, with advantage.

Dwyer, B. and Hutchings, K. (1977). Flowchart Optimisation in COPE a Multi-Choice Decision Table. Australian Computer Journal 9(3): 92-100.

The operation of a processor is described which will convert decision tables to COBOL programs. The notation for decision tables has been extended to allow the expression of arbitrary flowcharts. Multi-choice entry is presented as a convenient alternative to extended-entry notation. The paper describes the conversion of a decision table to a feasible flowchart, the subsequent transformation of the flow chart to minimise storage required by the program, and selection of the sequence in which code is generated.

Dwyer, T. (2001). Three Dimensional UML Using Force Directed Layout. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Eades, P., Lin, X. and Wormald, N. C. (1993). Performance Guarantees for Motion Planning with Temporal Uncertainty. Australian Computer Journal 25(1): 21-28.

Recently, Computational Geometry has contribute many new algorithms for planning the motion of a point mobile robot from its start to its target in a field of obstacles. A typical aim of such an algorithm is to find a shortest path using minimal computation time. Most algorithms assume that the motion planner has complete information, in other words, that the set of obstacles is known to the robot before it leaves the start point. The advantage of the Computational Geometry approach is that the performance of the motion planner may be rigorously analysed using mathematical methods. As such, this approach is popular with theorists who generally believe in the Grand Ideal of Computer Science, that software should be guaranteed by mathematical proof. In practice, the physical constraints of robotics are myriad and seem impossible to define precisely in mathematical terms; thus the methods of Computational Geometry have had limited applicability. From this point of view, it seems that the performance of motion planners must be measured by experience, and the Grand Ideal must be abandoned. In this paper we present recent research which represents a small step toward resolving this dilemma, by considering a robot with the physical constraint of temporal uncertainty. The inputs to the motion planner arrive sequentially, and the robot must act on one input before it receives the next. Specifically, the robot can only perceive an obstacle when it bumps into it. Of course such a robot cannot find a shortest path from its start to its target, and the usual shortest path algorithms from Computational Geometry are of little significance. We show that, however, this constraint does not preclude a rigorous mathematical analysis. Specifically, we present "performance guarantees" for such a robot in a simple environment: we measure the ratio P of the length of the robot's path to the length of the shortest path. The main results are upper and lower bounds for P. The results fall far short of considering all the constraints of a real robot. However, we believe that they show that the gap between the theoretical approach of Computational Geometry and realistic robots can be reduced.

Earle, T. R. and Fitzgerald, E. P. (1983). Professionalism - Its Educational Aspects. Australian Computer Journal 15(3): 86-90.

The majority of decisions of the Australian Computer Society have been concerned with the education and training of computer professionals. Problems may occur when a professional organisation sets educational requirements, for example, credential creep, artificial barriers, stereotyped courses through control of accreditation, and training rather than education. Strategies for overcoming these problems and enhancing future professional standing are discussed.

Edmundson, R. H. and Tery, J. E. (1986). Graphical Data Presentation for Decision Support Systems. Australian Computer Journal 18(4): 191-195.

This paper addresses the effectiveness of the use of interactive graphical techniques in the design of the data interface of decision support systems. It has been shown that the transposition of the previously used hard copy forms design to the screen environment may not lead to an improvement in decision outcome. An improvement may arise from the appropriate use of the interactive capabilities of modern graphics facilities.

Edwards, J. (2001). John Makepeace Bennett - An Inspiration. Journal of Research and Practice in Information Technology 33(4): 273-279. First Page.

Edwards, J. and Kay, J. (2001). A Sorry Tale - A Study of Women's Participation in IT Higher Education in Australia. Journal of Research and Practice in Information Technology 33(4): 329-335. First Page.

El-Qawasmeh, E. (2000). Performance Investigation of Bit-Counting Algorithms with a Speedup to Lookup Table. Journal of Research and Practice in Information Technology 32(3/4): 215-230. First Page.

Bit-counting refers to the operation of counting the number of "1"s in a given computer word or binary vector. Currently there are several algorithms to solve this problem. The simplest one is serial shifting. Many recent algorithms have evolved in the last few years to overcome the slowness of serial shifting. However, their performance behaviour was not studied deeply. In this paper, the performance behaviour of existing algorithms will be investigated with clarifying comments. Moreover, an enhanced lookup table algorithm that is faster than the existing algorithms is presented and evaluated.

Elliot, S. (1993). Formal Computing Education in Australia: Do We Practise What We Teach? Australian Computer Journal 25(2): 49-60.

We teach that the discipline of computing promotes efficiency, effectiveness, and can be applied to increase the level of quality of an organisation's products and services. But do we apply these same principles to formal computing education? The Report of the Discipline Review of Computing Studies and Information Sciences Education, released in 1992, identified a number of principal problem areas. It is the contention of this paper that many of these problem areas would benefit from the application of our discipline. This paper examines the range of technologies applicable to education; considers the results of a survey into the use of Educational Technology in computing courses in Australia; looks at international experience with Educational technologies in computing courses; and draws conclusions about their applicability to address problems identified with computing education in Australia.

Ellison, M. and McGrath, G. M. (1998). Recording and Analysing Business Processes: An Activity Theory Based Approach. Australian Computer Journal 30(4): 146-152.

This paper sets out a conceptual framework for business process modelling based on activity theory and a research program of collaborative research with a high-tech service organisation to validate this framework. This research program includes the construction of an automated system to record the organisation's business processes for later analysis using a knowledge-based system. Particular attention is paid to soft factors such as understandings, norms, beliefs and motives.

Elsum, D. L. (1972). How to Succeed with ADP. Australian Computer Journal 4(4): 157-163.

Organisations using ADP have frequently had to grapple with a range of over-ambitious schemes that have been under-estimated in size and complexity and which have, in short, failed to produce the promised results on time.

Enfield, l. D. (1969). A Note on an Editing Problem Involving Several Data Representations. Australian Computer Journal 1(5): 258-266.

This note describes and evaluates an efficient method of searching and maintaining a data base representation of variable-length items. The method, which has been implemented in a business compiler on a word-processor, involved the application of mapped-, chained-, and partitioned data representations. As far as possible the terminology of the IFIP-ICC Vocabulary of Information Processing (1966) is used throughout the note.

Evered, M. (2002). Bracket Capabilities for Distributed Systems Security. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Evered, M. (2002). Opsis - A Distributed Object Architecture Based on Bracket Capabilities. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Fabre, J., Howard, S. and Smith, R. (2001). Designing the Temporal Aspects of the User Interface: View from the Coal Face. Journal of Research and Practice in Information Technology 33(1): 54-67. First Page.

We aim to support user interface designers in capturing, representing and reasoning about temporal information. We have developed a method to support user interface designers in considering how the temporal aspects of software impact the user. Importantly the method is based on a detailed analysis of data from a set of situated interviews that capture the views of practicing user interface designers. This paper discusses the background research and the motivation for the method.

Farrell, R. (1987). A Guide to Software Quality for the Developer and Unwary User. Australian Computer Journal 19(4): 219-221.

Quality assurance methodologies have been part and parcel of the manufacturing environment for many years, and over the past few years have even greater emphasis. It is now becoming obvious that in order to make better use of limited resources we must apply these disciplines to the software development process. Stowe's R&D experience over the past four years has shown that it is possible to provide users with software with a minimal number of defects and that the cost of doing so is much less than if the techniques are ignored.

Fatoohi, R., Gunwani, V., Wang, Q. and Zheng, C. (2001). Performance Evaluation of Middleware Bridging Technologies. Journal of Research and Practice in Information Technology 33(2): 107-119. First Page.

In today 's market,there are several middleware technologies, including: the Distributed Computing Environment (DCE),the Common Object Request Broker Architecture (CORBA), and the Distributed Component Object Model (DCOM). However,the underlying middleware components are incompatible; and therefore,a high-level heterogeneity problem has been created. Recently, software "bridges" have emerged that enable interoperability between different middleware environments. This paper presents the results of experiments to evaluate bridging technology using two DCOM-CORBA bridges and a DCE-CORBA bridge. Several configurations, depending on the number of machines and location of the bridge,are employed and two languages (C++and Java) are used. The results show that the three bridges perform reasonably well for different configurations and language mappings.

Feng, M.-D. and Yuen, C.-K. (1995). Parallel Lisp Compilation for Distributed Systems. Australian Computer Journal 27(3): 77-91.

The advent of high speed VLSI CMOS chips has made low cost parallel processing feasible. To use parallel computers efficiently for symbolic computing, both an expressively powerful symbolic language, e.g. parallel Lisp or Prolog, and its efficient implementation are required. This paper reports the effort of building a compiler for BaLinda Lisp, a parallel Lisp dialect, on distributed-memory multiprocessors. BaLinda Lisp supports the construct to initiate parallel execution threads, speculative computation to spawn parallel tasks for results that may be required, and Linda tuplespace operations to enforce proper communication and synchronisation. The compiling of BaLinda Lisp consists of several passes and generates code for an intermediate abstract machine. We will show how the salient features of BaLinda Lisp could be fully, described by lower-level abstract machine instructions and will explain the abstract machine and its instruction set. The execution model is based on group managing, allowing processors to form groups of different sizes in order to distribute the execution control mechanism. Experiments are carried out on a network of up to 18 transputers in various configurations. The results show that the compiler generates efficient code for sequential BaLinda Lisp programs and, following upon this, parallel BaLinda Lisp programs could run much faster such that reasonable speedup could be achieved in most situations.

Fenwick, P. M. (1972). A Binary Representation for Decimal Numbers. Australian Computer Journal 4(4): 146-149.

A number system is described which combines the programming convenience of decimal numbers with the hardware advantages of binary arithmetic. The number format resembles some integer floating-point formats, except that the exponent is associated with a base of ten, rather than some power of 2. It is shown that the arithmetic in the new representation is little more difficult than for ordinary floating-point numbers, and methods are given for implementing the "decimal" shifts which are a consequence of the exponent base.

Ferme, W. D. (1987). What Could a Client Reasonably Expect a Consultant to do When He is Engaged to Assist in the Purchase of a Manufacturing System. Australian Computer Journal 19(4): 196-202.

The purpose of this paper is to give some guidance to managers of manufacturing organisations that are considering the introduction of computer-based information systems. By highlighting the major problem areas and providing a number of checklists of optional solutions, the manager should gain some insight into the processes that should be followed by a consultant giving advice in this area.

Fernandez, J. I. (1984). Protocol Translation for Packet Network Interconnection. Australian Computer Journal 16(1): 14-21.

Two or more packet switching networks can be connected together by implementing a gateway that translates between the generally incompatible protocols of the different networks. One such implementation of protocol translation is considered in detail. This is used to illustrate the problems involved and possible solutions of them.

Fernando, L. (1988). Contentious Issues in the Quest for EFT Security Standards. Australian Computer Journal 20(4): 178-180.

Many interests are represented on the International and National Standards Committees responsible for the preparation of EFT security standards. In view of the diversity of interests there are often occasions when some aspects of the standard are intensely debated and not always resolved. This paper will endeavour to identify some of these contentious issues, to detail the opposing arguments and to offer some suggestions for resolution where resolution has not been reached. The paper will also deal in general with the need for and degrees of usefulness of security, the push for legislation to cover EFT security, the privacy issues and the advantages and disadvantages of national standards pre-empting international standards.

Ferreira-Cabrera, A. and Atkinson-Abutridy, J. A. (2002). A Model for Generating Explanatory Web-based Natural-Language Dialogue Interactions for Document Filtering. Journal of Research and Practice in Information Technology 34(1): 2-19. First Page.

A computational linguistics approach for Web-based cooperative dialogues aimed at improving results in achieving a successful filtered bibliographic search on the Web is presented. The model focuses on the user's requests by automatically generating language-driven interactions which take into account the context, user's feedback and the initial search results. The main results of a preliminary working prototype to decrease both the number of conversational turns and the amount of information obtained are described.

Fetherston, T. (2002). What Information and Communication Technologies Courses Should Be Taught at a New Senior College?. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Fidge, C. J. (1987). Reproducible Tests in CSP. Australian Computer Journal 19(2): 92-98.

The difficulty of testing and debugging CSP programs is compounded by their inherent non-determinism. We illustrate a simple approach to recording and replaying traces of the control paths followed as a means of controlling this unpredictability. Where these traces would become unmanageably long, a variant of Bouge's repeated snapshot algorithm is used to put an upper bound on trace length. Some knowledge of CSP is assumed.

Fidge, C. J. and Pascoe, R. S. V. (1983). A Comparison of the Concurrency Constructs and Module Facilities of CHILL and Ada. Australian Computer Journal 15(1): 17-27.

The concurrency and modularisation features of two new programming languages, both the product of large design efforts, and both with similar aims and application areas, are summarised and compared. CHILL and Ada, despite global similarities, present quite different approaches to these two problem areas and it is shown that the Ada mechanism is slightly superior in both cases.

Fiedler, M. R. G. (1969). Education For Commercial ADP Staff - I Skills Required and Existing Facilities. Australian Computer Journal 1(5): 277-284.

This paper is presented in two parts. I, printed in this issue, outlines the skills and disciplines required by the various classes of A.D.P. staff. It then attempts a critical assessment of existing facilities for commercial A.D.P. education in Australia and finds these facilities wanting on two main scores - first, there is an insufficient supply of trained staff forthcoming from existing training institutions to meet present and projected future requirements and, secondly, such graduates, diplomates, etc., produced are not yet ready to enter the practical work situation. Certain suggestions for the implementation of an in-house training scheme will be given in II of this paper (to be published in the February 1970, issue of the Australian Computer Journal).

Fiedler, M. R. G. (1970). Education For Commercial ADP Staff In Australia II - The Solution In-House Training. Australian Computer Journal 2(1): 32-38.

Part I of this paper, published in the November 1969 issue of the Australian Computer Journal, attempted a critical assessment of existing facilities for commercial A.D.P. education in Australia and found these facilities wanting on two main scores; (a) there is an insufficient supply of trained staff forthcoming from existing training institutions to meet present and projected future requirements and (b) such graduates, diplomates, etc., produced are not yet ready to enter the practical work situation. In this issue, a highly developed scheme of in-house training is commended to all users, to be adopted primarily as a means of bridging the gap between the supply of and demand for adequately trained staff. Certain suggestions for the implementation of an in-house training scheme are given, together with a consideration of the advantages and disadvantages of such a scheme, while some actual schemes operating successfully in Australia are described.

Filsell, J. and Barnes, A. (2002). Researching Pedagogy and Teaching Methodologies that Transform Student Learning in South Australian Classrooms. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Finkel, R. A., Zaslavsky, A., Monostori, K. and Schmidt, H. (2002). Signature Extraction for Overlap Detection in Documents. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Finkelstein, C. (1981). Procedure Formation - Derivation of Procedures for Users by Users. Australian Computer Journal 13(4): 127-135.

Procedure formation allows user management to examine their objectives in the light of data resources, and to derive what an organisation's procedures "should be". The method formally identifies procedural opportunities and provides feedback of new procedures and of application boundaries.

Finkelstein, C. B. (1970). Data Entry Techniques. Australian Computer Journal 2(4): 146-155.

This paper discusses various techniques for entering data into a computer system. The advantages and disadvantages of Card Punching, Paper Tape Punching, Magnetic Tape Encoding, Optical Mark Reading (OMR), Optical Character Reading (OCR), Magnetic Ink Character Reading (MICR), Cathode Ray Tube (CRT) Display Units and remote terminals are examined. Applications to which these various data entry techniques apply are discussed, and examples are given of Australian users who employ these techniques. Factors which are important in the cost justification of OCR and CRT for data entry are detailed, and cost comparisons of OCR and CRT compared with card punching are given. A graphical comparison of the costs involved with each data entry technique is shown for a typical installation.

Finn, G. D. (1996). Genetic Algorithm for Fine-Tuning Fuzzy Rules for the Cart-Pole Balancing System. Australian Computer Journal 28(4): 128-137.

Genetic algorithms are used to fine-tune the membership functions and, especially, the large number of fuzzy rules for controlling a cart-pole dynamical system where a hinged pole is supposed to balance on a powered cart confined to a finite length of straight track. The fitness function is determined by the total number of steps to failure of computer simulations (up to a maximum number identified with success) for various initial configurations. Starting from a reasonably knowledgeable set of rules the genetic algorithm efficiently leads to a superior set which provides balance in both bang bang and continuous force modes for a range of update times. It is possible to start with a random set of rules but the derivation of a good set takes much longer. It was found possible to exert influence on the quality of balance by subtracting a penalty from the fitness function for simulations which only provide noticeably unsteady balance. As well, it is shown that a single set of fuzzy rules can be used to achieve a state of balance at essentially arbitrary positions of the cart on the track.

Fischmeister, S., Menkhaus, G. and Pree, W. (2002). MUSA-Shadow: Concepts, Implementation and Sample Applications - A Location-Based Service Supporting Multiple Devices. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Fisher, J. (1999). The Importance of User Message Text and Why Professional Writers Should Be Involved. Australian Computer Journal 31(4): 118-123.

System status and error messages are the most frequently occurring forms of communication between an information system and a user. These messages often communicate critical information and yet they are regularly not written in the most accessible way. The consruction, display and style of the messages will impact ultimately on the usability and costs of a system. This paper reports on research which identified problems with the current approach to the development and writing of system and error message text and proposes using specialist communication expertise so that users will be happier and will interact more effectively with information systems.

Foo, N., Kwok, R. and Zhang, Y. (2001). Apparent Nondeterminism in Actions. Journal of Research and Practice in Information Technology 33(4): 360-368. First Page.

Forbes, K. (1972). Random Files and a Subroutine for Creating a Random Address. Australian Computer Journal 4(1): 35-39.

This paper briefly discusses random files and describes in some detail an algorithm for creating a storage address which is apparently just as likely to be any place in the file as any other - i.e. a pseudo-random address. This algorithm differs form most others in that it is designed to work on any type of record key. Assuming this property, formulae for calculating rates of overflow records are derived. Optimum packing densities of the file can then be decided upon.

Fox, M. (1979). On Apportioning and Rounding. Australian Computer Journal 11(3): 108-111.

The apportioning and rounding problem described in Coote (February 1979) is shown to reduce to a simple linear program. The formulation defines an assignment problem capable of hand or computer solution and exhibiting maximum accuracy.

Fraser, D. (1987). A Conceptual Image Intensity Surface and the Sampling Theorem. Australian Computer Journal 19(3): 119-125.

The sampling theorem provides a theoretical basis for treating a discrete data sequence, such as a digital image, as a continuous "real world" distribution. The sampling theorem is often either ignored or not always fully understood, and this paper attempts to put the theorem in perspective. The paper mentions recent work on interpolation by the FFT and discusses its relevance to recent spatial transformation algorithms, and proposes that a digital image be viewed in terms of a "conceptual intensity surface", reconstructed from the coefficients of its DFT (i.e. the sampling theorem in a new light). The concept of a surface is particularly important when it becomes necessary to "resample" an image, which occurs whenever a spatial transformation is required. Neglect of the conceptual intensity surface may lead to aliasing and to the corruption of the high spatial frequency content of an image. The paper gives a detailed discussion of these effects, including proposed solutions.

Frasincar, F., Houben, G.-J. and Pau, C. (2002). XAL: An Algebra For XML Query Optimization. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Frazer, M. (1988). The Development of VBARS: An Applied Expert System. Australian Computer Journal 20(4): 181-187.

In December 1987, use of an expert system to provide advice on assistance to new or small businesses commenced in Melbourne. The system has been developed by BBJ Computers International Pty Ltd of South Melbourne, for the Victorian Government's Department of Industry technology and Resources. This paper discusses three matters the Department's motivation in commissioning the system, the planning and development of the system, and its use. The presentation is from the point of view of the Department as the client, rather than from the point of view of the technical developers of the system.

Fris, I. and Smith, A. G. (1974). A Student Programming CMI System on an ICL 1904A. Australian Computer Journal 6(1): 12-17.

A CMI system applied to the teaching of undergraduate programming courses is described. The system consists of program modules controlled by a main program written in the PLAN 3 assembler language which makes use of ICL's range compatible trusted facility. The system utilises manufacturer-supplied compilers, and although it is specifically applied to the teaching of FORTRAN, it may be used equally well in the teaching of any language for which there is a compiler.

Fry, M. and Ghosh, A. (1996). Some Issues for Dynamic Synthesis of ALF/ILP Systems. Australian Computer Journal 28(2): 61-65.

ALF and ILP are powerful principles that guide the construction of application specific, high performance systems. This paper explores some ideas for modular construction of ALF/ILP systems. We consider how flexible "filter pipelines" may be dynamically synthesised at run time, while achieving high performance. We further consider the application of ILP to a complex, distributed multimedia application . Our results illustrate some of the trade-offs in constructing adaptable, high performance systems.

Fry, M. R. (1987). The Transport Layer in a Microcomputer Network. Australian Computer Journal 19(2): 56-62.

The layered protocol approach to computer network architecture has gained ascendancy in recent years due to activity in the area of Open Systems Interconnection. This paper reports on a research project to investigate layered design and construction in the environment of a local area network for microcomputers. Special emphasis is given to the transport layer protocol used in the project, since this layer arises as a unifying point in the architecture. Issues highlighted are the trade-off between the advantages of layered design versus the 'end-to-end argument' and the limitations to network functionality - especially of the transport layer - that are caused by the resident operating system.

Fry, M. R. (1996). Management of the IT Industry: A Survey of Critical Challenges. Australian Computer Journal 28(3): 88-95.

The IT industry is reliant on (inter alia) human resources for its competitivenass. The need for appropriate technical expertise has been well recognised and studied. However, the question of how well middle and upper level managers are equiped to meet the management challenges of the industry has not been explored. The paper reports on an industry survey that was conducted in New South Wales to answer this and other questions. The survey has indicated deficiencies in management skill, which may be impacting the ability of companies to achieve core business objectives. Thus, the problem of management skills may be an impediment to the growth and competitiveness of the IT industry. The outcomes of the survey have prompted the development and sponsorship of a new Management Development Program for the IT Industry.

Fu, J.-S. and Chen, G.-H. (2002). Pancycles and Hamiltonian-Connectedness of the Hierarchical Cubic Network. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Fuad, M. M. and Oudshoorn, M. J. (2002). AdJava - Automatic Distribution of Java Applications. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Fuericht, R., Prahofer, H., Hofinger, T. and Altmann, J. (2002). A Component-Based Application Framework for Manufactruing Execution Systems in C\# and .NET. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Fung, M., Henderson-Sellers, B. and Yap, L.-M. (1997). A Comparative Evaluation of 00 Methodologies from a Business Rules and Quality Perspective. Australian Computer Journal 29(3): 95-101.

Comparisons of object-oriented (OO) methodologies have previously been undertaken using a "checkbox" approach to identify whether they support specific technical features, such as aggregation, multiple inheritance, use cases. Here we focus on support for buisiness related issues, specifically business rules and a quality approach to software development. A selection of five methodologies is made for illustrative purposes. Whilst all five support the main technical features of the object-oriented paradigm, none offer full support for business rules. Several (but not all) have a quality element some better than others; the most neglected software quantity attribute being integrity/security. This survey thus focuses attention on possible "gaps' as a basis for future methodological development.

Gaines, B. R. and Shaw, M. L. G. (2001). Human-Computer Interaction in Online Communities. Journal of Research and Practice in Information Technology 33(1): 3-15. First Page.

One major impact of the Internet (net) has been its support for computer-mediated online communities. Communication through email and list servers and shared information archives through web browsers and servers support the discourse and knowledge processes of on-line communities in such a novel and effective way as to be revolutionary. Human-computer interaction (HCI) issues arise in the support of individual users of the Internet because the rapid growth of the technology has been achieved by repurposing existing tools without necessarily taking into account novel requirements. There are also new HCI issues emerging at the community level, and tools are being built that add to the effectiveness of such communities by organizing their knowledge products, supporting awareness of new material, attracting relevant members, and so on. This article addresses issues of HCI in online communities, the underlying cognitive, cultural, social and media theories, empirical modeling of community processes, and the use of the results to improve the supporting technology.

Galliers, R. D. (1987). Information Systems Planning: A Manifesto for Australian-Based Research. Australian Computer Journal 19(2): 49-55.

Information Systems Planning is a key issue facing organisations generally and the information systems profession in particular in the latter half of the 1980s. Notwithstanding this high level of interest and activity, there have been few examples of comprehensive research which access current information systems planning endeavours with a view to providing practical guidelines for improving the practice. This paper reviews the limited empirical research that has been undertaken and notes in particular that little evidence indeed exists as to the state-of-the-art of information systems planning in Australia. It proposes a research programme, which is an extension of survey research already undertaken by the author in the United Kingdom, designed to remedy the situation and which will provide the first direct trans-national comparisons within this topic area. The research aims to develop guidelines which may assist those attempting to choose appropriate information systems planning efforts, and to make recommendations aimed at improving the efficacy of information systems planning endeavours in Australia.

Gammack, J. G. and Goulding, P. R. (1999). Ethical Responsibility and the Management of Knowledge. Australian Computer Journal 31(3): 72-77.

In this paper we address the issue of how unconsidered information systems developments contribute to an abuse of human values and potential. Unforseen uses of data in information systems suggests that the level at which codes of IS ethics are typically detailed is insufficient to ensure real social responsibility. The burgeoning field of knowledge management exemplifies some dangerous directions potential in many comntemporary IS developments. We suggest that a conceptualisation of human knowledge embracing non-Western insights, and of the creative role of knowledgeable humans, is required both for IS education and truly ethical practice.

Garner, B. J. and Pinnis, J. (1984). Modelling as an Audit Technique. Australian Computer Journal 16(2): 48-53.

This paper explores the creation and use of audit models as powerful new tools for the EDP auditor. A paradigm for model representation is offered as an extension of current methodology for systems-based auditing, and three types of audit model are defined. Research results are reported on the application of detective audit models to testing for compliance with general (environmental) controls.

Garner, B. J. and Tsui, E. (1985). Knowledge Representation for an Audit Office. Australian Computer Journal 17(3): 106-112.

This paper explores the advanced functions and associated knowledge representation issues appropriate to the Office of the Future through research into automation of the Audit Office. Four broad conclusions have emerged from this research with important implications for the design of Office Knowledge Bases, and the development of a Conceptual Schema for the Audit Office using canonical graphs has been demonstrated.

George, S. E. (2002). Learning and the Reflective Journal in Computer Science. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Ghosh, A. and Crowcroft, J. (1996). Some Lessons Learned from Various ALF and ILP Applications. Australian Computer Journal 28(2): 42-47.

Application Level Framing ALF is considered a mechanism for building high bandwidth applications. We have built three diverse applications to show that even for low bandwidth applications it has its merits. A problem however is that a good knowledge of both the application and networking is required in order to build ALF based applications. There are currently no aids in the building of ALF based applications. We attempt to identify some common components in our diverse applications which could be used to aid in the building of future ALF based applications.

Ghosh, S., Bawa, N., Craig, G. and Kalgaonkar, K. (2001). An Extensible Framework for Testing Distributed Java Applications. Journal of Research and Practice in Information Technology 33(2): 120-132. First Page.

Testing applications involves the creation of test sets,their execution,management and adequacy assessment. An extensible framework, called RiOT, has been developed to allow the implementation of tools for test coverage measurement, test execution management and fault-based testing of distributed Java applications. Test coverage is measured in terms of elements covered in the interface description of an application's components. Mutation operators for interface mutation analysis are proposed and their implementation described. Fault injection testing for the assessment of the application's fault tolerance properties is made possible using the fault injection mechanism of the framework. An extension of the framework to allow test monitoring and control is described. The framework uses a hierarchical form of data communication between its different modules. The framework is designed to be scalable and easily extensible for future enhancements.

Giannoccaro, A., Shanks, G. and Darke, P. (1999). Stakeholder Perceptions of Data Quality in a Data Warehouse Environment. Australian Computer Journal 31(4): 110-116.

The quality of the data provided is critical to the success of data warehousing initatives. There is strong evidence that many organisations have significant data quality problems, and that these have substantial social and economic impacts. This paper describes a study which explores the perceptions of various stakeholders in the data warehousing environment concerning their data quality requirements. The study involved the development of a conceptual framework representing the relationships between stakeholder types and data quality dimensions, and the application of the framework in a case study of data quality in a data warehouse at a large transport company. The case study findings suggest that improved training in data warehouse usage is necessary to help data consumers better understand the data, that reward structures should be established to help ensure data quality compliance, and that the importance of data quality needs to be better communicated.

Gibbins, D., Brooks, M. J. and Chojnacki, W. (1991). Light Source Direction from a Single Image: A Performance Analysis. Australian Computer Journal 23(4): 165-174.

A smooth object depicted in a photograph will often exhibit brightness variation or shading. Of interest in computer vision is the problem of how object shape may be determined from image shading. Various computational techniques have emerged that perform reasonably well in solving this problem. However, these methods typically require substantial scene information prior to commencement. This requirement can be reduced by using preprocessing techniques to estimate, for a given image, the direction of the principal light source, or "sun". In this paper, we conduct a comparative performance analysis of these techniques, revealing the poor versatility. An informal study is undertaken of the ability of people to perceive the principal light source direction from synthesised images. Some implications of this work for models of cognition are discussed.

Gilmour, P. (1972). Applied Industrial Computer Simulation - A Dynamic Physical Distribution Model. Australian Computer Journal 4(2): 58-64.

Computer simulation is fast becoming a vital decision making tool for industrial management. This paper describes a dynamic long term planning model for an industrial physical distribution system. The model is general in nature and is currently in operation for a large manufacturer and distributor of consumer goods.

Gilmour, P. (1973). A General Validation Procedure for Computer Simulation Models. Australian Computer Journal 5(3): 127-131.

This paper describes a generalized procedure for testing the validity of computer simulation experiments. Before this procedure can be applied the experimental results must satisfy the problem-dependent conditions of face validity testing. Then the general procedure, or a subset of it if cost or computational restrictions exist, is applied. An index of validity provides a basis for intramodel analysis and intermodel comparison.

Gipps, J. (2002). Data Logging and Inquiry Learning in Science. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Gledhill, V. X. (1972). Medical Decision Making by Computer. Australian Computer Journal 4(1): 12-15.

Much Medical data is traditionally "soft' and qualitative. Questionnaires and check-lists can be used to "harden" this data; resulting in dichotomous descriptors can be used as a basis for medical decision-making in the areas of diagnosis, investigation and treatment planning. The Computer Aided Learning Model (CALM) uses a learning set of data (from patients whose decisions are known) to evaluate the significance of each descriptor for each decision. Subsequently CAL< is able to process the descriptors from new patients to successfully predict the appropriate decisions.

Godfrey, B. (2001). Electronic Work Monitoring: An Ethical Model. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

This paper describes the activity of electronic work-monitoring, the use of information technology to record the activities of workers as a background task to normal activities. The viewpoint of the activity from the employer side, as a productivity tool, and the view from the employee perspective, as a possible invasion of privacy, are compared. A quadrant model is described which combines these two conflicting viewpoints, and details how the model may be used to describe and if possible resolve potential conflicts of interest between employees and employers.

Goldsworthy, A. W. (1968). The Proliferation of Ignorance. Australian Computer Journal 1(2): 109-112.

Increasing attention is being paid to the education and training of people for careers in data processing. However, too little attention is being paid to the serious lack in training and knowledge of many of the existing cadre of data processing people, those who are now,and will be in the future, holding positions of responsibility in the field. It is suggested that the present corps of data processing people are far too complacent with their present breadth and depth of knowledge and that the situation calls for urgent and positive action to rectify this. Some suggestions are made as to how this might be done.

Goldsworthy, A. W. (1970). Generalised Input - Data Editing. Australian Computer Journal 2(4): 166-172.

In any data processing system one of the most important aspects of the processing cycle is the editing phase, during which data are subjected to a variety of tests and checks to ensure that they enter the next stage of the system as accurate and reliable as possible. In a large-scale system editing becomes increasingly important. With large-scale systems which are also dynamic in nature, constant changes to data structures generate changes to editing specifications which usually result in program changes. Program maintenance therefore becomes a problem. Also, if each suite of editing programs is written from the ground up at the outset, this is obviously a lot of unnecessary duplication. This paper describes a generalised system which enables some of these problems to be overcome with a considerable saving of programming effort.

Goldsworthy, A. W. (1972). INSURE - An Online Insurance System. Australian Computer Journal 4(3): 127-134.

This paper discusses the on-line facilities that are in use and some that are being developed in the State Government Insurance Office (Queensland). The systems described have been in use for almost two years and make extensive use of Visual Display Units (CRT's). This paper outlines the design philosophies underlying the systems and describes the design structures of the retrieval keys, data items and files used, with some discussion on the program structure of the overall system. The paper indicates the benefits to be achieved from systems such as this and comments on their acceptance by users.

Goldsworthy, A. W. (1972). MAK at the SGIO - A Practical Implementation of an Online Data Entry System. Australian Computer Journal 4(2): 65-72.

This paper comments on the traditional methods of data preparation in common use, and on the need for re-appraisal of present data preparation methods. The philosophy adopted by SGIO is discussed together with a description of the system implemented and the provision made for further development.

Goldsworthy, A. W. (1973). Computers and Privacy - A Review of the Younger Committee Report. Australian Computer Journal 5(1): 3-7.

The Younger Committee Report on Privacy was recently presented to the U.K. Parliament. This paper reviews those sections of the Report especially relevant to computer practitioners. The report is an important one in the area of privacy and is relevant to the current considerations of the Australian Computer Society on this issue. The paper highlights the issues raised in the Report and in discussing the conclusions and recommendations of the Committee relates these specifically to the problems of computers and their users.

Goldsworthy, A. W. (1974). Privacy in Australia - the Morison Report. Australian Computer Journal 6(1): 34-37.

The issue of individual privacy continues to receive considerable public attention. One of the major aspects of this problem relates to the privacy of information. It is important for computer practitioners to remain conversant with current developments. This paper reviews the Report presented by Prof. Morison, which is the first in-depth study of this issue in Australia.

Goldsworthy, A. W. (1977). Computers and their Social Implications in the Australian Scene. Australian Computer Journal 9(1): 25-31.

The history of the activity in Australia in the field of the impact of Computers on Society is sketched and some of the important current issues are discussed.

Goldsworthy, A. W. (1978). Eighth World Computer Congress. Australian Computer Journal 10(2): 50-52.

Goldsworthy, A. W. (1993). IT and the Competency Debate-Skill vs. Knowledge A Major Issue. Australian Computer Journal 25(3): 113-122.

The development of national competency-based standards for the professions is part of a movement sweeping the broader educational sector. It poses some fundamental questions for all professions, including the IT profession. It will have far-reaching effects and unless clearly understood and carefully managed has the potential to be a disaster for the IT profession, its growth and development, not only as a profession but as a discipline. The paper highlights the main features of the process and some of the major underlying issues which all thinking IT professionals should be concerned about.

Goldsworthy, A. W. and Jenkins, I. A. (1975). Some Problems of Online Systems Development. Australian Computer Journal 7(3): 132-139.

This paper discusses some of the major problems met in designing on-line systems. The paper is based on practical experience with such systems in a large insurance company over a period of some years. The solutions implemented are also discussed. Consideration is given to all aspects of development from basic system design to the provision of comprehensive information to management. Finally the strictly human problems faced by users of an on-line system are highlighted.

Golic, J. D., Clark, A. and Dawson, E. (1999). Inversion Attack and Branching. Australian Computer Journal 31(2): 44-53.

The generalised inversion attack on nonlinear filter generators is developed and analysed by the theory of critical branching processes. Unlike the inversion attack which requires that the filter function be linear in the first or the last input variable, this attack can be applied for any filter function. Both theory and systematic experiments conducted show that its time complexity remains close to 2superM, M being the input memory size, while the additional memory space required is relatively small for most of the filter functions.

Goodspeed, M. J. (1970). The Computation of Solar Position in Environmental Models. Australian Computer Journal 2(3): 110-113.

The repetitive computation of solar position required in some environmental models suggested the need to reexamine the traditional methods used, from the point of view of computational efficiency. The method advocated here reverts to the heliocentric view of Copernicus and Kepler, and employs a vector-arithmetic package to eliminate much unnecessary evaluation of trigonometric functions.

Goscinski, A. and Haddock, A. (1994). A Naming and Trading Facility for a Distributed System. Australian Computer Journal 26(2): 50-65.

In this paper, we demonstrate that the design of a naming and trading facility for the RHODOS system which provides autonomy and flexibility to users yet at the same time allows them to share all accessible system and application objects ( resources, services) is feasible. We show that autonomy and sharing can be achieved if three basic constructs are introduced. First, two groups of sharable objects are distinguished in the RHODOS domain: those which are owned by the system and those which are owned by each individual user. Second, these groups of objects form separate system/administrator domain and user domains, respectively. Third the possibility of exporting and importing objects to/from other domains is introduced. The exported objects form an export/import (trading) domain. This domain allows users to access (providing they have access rights) imported objects (resources and/or services) which are not available in their private domains. We discuss in detail the need for, and the influence of naming database distribution on the architecture of the attributed naming facilicity. We also show that attribute names improve friendliness by enabling a user to make an enquiry on an objective and/or access an object without the knowledge of its user name. Finally, it is demonstrated that this naming and trading facility concept can be used in a heterogeneous environment to support open didtributed processing.

Gostick, R. W. (1981). Software and Hardware Technology for the ICL Distributed Array Processor. Australian Computer Journal 13(1): 1-6.

The ICL Distributed Array Processor (DAP) is a radical departure from conventional computer architectures. Advances in both hardware technology and software technology have been combined to produce a new type of high speed computer. This paper concentrates on the relationship between the hardware and the software, and shows how the various components have been integrated within the 2900 system.

Gough, K. J., Mohay, G. and Pease, W. (1991). Realtime Programming in Modula-2. Australian Computer Journal 23(4): 175-184.

The unit of pseudo-parallelism in Modula-2 is the coroutine; coroutines switch control to one another through the use of simple coroutine TRANSFER operations. In the case of programs which need to cater for realtime events (i.e. interupts) an I/O coroutine awaiting an interrupt suspends itself pending the occurrence of the specified interrupt using the IOTRANSFER operation. Recognition of the awaited interupt, when it occurs, then causes execution of an asynchronous coroutine transfer which despatches the awaiting I/O coroutine. The module priority mechanism ensures inter alia, that other interrupts occurring during execution of that I/O or device handler coroutine will only be recognised if they are of higher priority. A modified set of Modula-2 coroutine primitives, prototyped using the PDP-11 M23 Modula-2 system, has been described previously. That model included the new primitive operation Attachinterrupt which effectively replaces IOTRANSFER, leading to an arguably simpler and more elegant structure for real-time pseudo- parallel Modula-2 programs. That model has now been extended to incorporate the additional primitive functions Priority and Previous respectively. The former provides a means by which a realtime coroutine may interrogate the priority of the coroutine which it has preempted (interrupted), while the latter is invoked by a coroutine in order to establish the identity of the coroutine which it has preempted via an interrupt or which it has succeeded via a synchronous transfer operation. This paper discusses the rationale for the extended model and its implementation in one of the most popular Modula-2 systems in use today, the Logitech Version 3 compiler for the IBM PC, and illustrates its use.

Graham, P. (1990). A Case Study of Computers in Public Administration: The Australia Card. Australian Computer Journal 22(2): 51-58.

Government departments are traditionally seen to guard their functional responsibilities against incursions by other departments or agencies. Indeed they normally appear alert to opportunities to extend their spheres of influence. In the case of the Australia Card debate, which took place between 1985-87, these conventional postures were abandoned. The Australian Tax Office and the Department of Social Security surrendered part of their potential territory to the Health Insurance Commission. The Health Commission's claim to the territory was based not on any functional prerogative but on its competence and capacity to apply computer technology. This paper is about the conditions under which computer technology overrides functional relationships in the development and implementation of government policies.

Grant, D. D. and Smith, R. (1992). Undergraduate Software Engineering - An Innovative Degree at Swinburne. Australian Computer Journal 24(3): 106-113.

In this paper we outline the context for the development of an undergraduate degree in Software Engineering in Australia, reflect on curriculum development ideas relevant to such a degree, and describe aspects of the Computer Science degree at Swinburne which, despite its title, may be viewed as a Software Engineering degree. We emphasisee the role of project-based units within the degree.

Grant, R. W. (1985). Office Automation - An Educational Perspective. Australian Computer Journal 17(3): 120-125.

This paper addresses the educational issues inherent in office automation. An overview of the current status of office automation is presented with particular discussion on approaches to user education. The need for education is discussed and the development of the educational initiatives at Chisholm Institute of Technology, to meet this need, is detailed. The role of the Business Technology Centre established at the Institute is described. The Centre model is an important development in meeting educational needs for this technological era.

Greenleaf, G. W. and Clarke, R. A. (1984). Database Retrieval Technology and Subject Access Principles. Australian Computer Journal 16(1): 27-32.

Thom and Thorne (1983) questioned the efficacy of proposed subject access to personal information because of features of relational databases. Those arguments are extended and a similar argument applied to free-text retrieval DBMS. Three sets of information privacy principles, those of the NSW Privacy Committee (1977), the OECD (1980) and the Australian Law Reform Commission (1983) are assessed against these difficulties. Weaknesses in these principles are identified. Suggestions for rationalisation of the Australian Information privacy debate are made.

Gregor, S. D., Rigney, H. M. and Smith, J. D. (1991). The Applicability of a Knowledge-Based System to Legal Education. Australian Computer Journal 23(1): 17-21.

The use of knowledge-based systems in law and as an aid to learning is examined. Particular difficulties in developing knowledge-based systems for legal applications are discussed. A knowledge-based system, CGTutor, which gives advice on capital gains tax is described. The system includes an explanation facility which offers more than answers to How and Why queries commonly offered in expert systems. The advice-giving functions of the system have been validated by tests with independent tax practitioners. An exploratory study in which the system was used as a learning aid by students studying taxation law indicated that the system had value in this role.

Gregory, G. and Sharpe, K. (1968). A Generalization of the Rejection Procedure for the Generation of Random Variables. Australian Computer Journal 1(3): 169-172.

It is shown how the simple rejection procedure may be generalized to cover the situation in which the range of the variable is infinite, subject to some mild restrictions. Methods for making the most efficient use of this generalized procedure are also discussed.

Gruhn, V., Mocker, M. and Schope, L. (2002). Development of an Electronic Commerce Portal System using a Specific Software Development Process. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Grundy, J., Newby, S., Whitmore, T. and Grundeman, P. (2002). Extending a Persistent Object Framework to Enhance Enterprise Application Server Performance. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Grundy, J., Wang, X. and Hosking, J. (2002). Building Multi-Device, Component-based, Thin-client Groupware: Issues and Experiences. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Gupta, G. K. (1977). A Course About Social Implications of Computing. Australian Computer Journal 9(3): 101-106.

This paper presents a brief description of a course about social implications of computing for B.Sc. honours year Computer Science students. The description includes a list of topics discussed and a partially annotated bibliography of some of the references used in the course.

Gwatling, J. C. (1973). Random Index File Design. Australian Computer Journal 5(1): 29-34.

An important aspect of modern digital computer systems is the efficiency in the use of random access storage for data files. This paper discusses a modified approach to the random access file design problem and compares it with a commonly used design. The results indicate that a file with the proposed structure shows a significant decrease in access and maintenance times. Although only fixed length records are considered throughout, modifications are suggested which would enable variable length records to be handled.

Halabi, A. K. and Tuovinen, J. E. (2002). Designing Better CBL than Face-to-Face Tutoring by Incorporating Teacher-like Feedback and Guidance in Accounting. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Halim, F. J. and Jin, J. S. (2002). View Synthesis by Image Mapping and Interpolation. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Hall, H. M. and Kidman, B. P. (1975). Run Monitoring of Student Programming. Australian Computer Journal 7(3): 127-131.

This report is primarily concerned with results obtained from an experimental monitoring of computer runs made by students while developing one particular BASIC program. High reported error rates and a wide variation in individual run patterns were found, a large number of runs being required by many students. The number of runs could not be related to the program text, but one parameter was found to be related to the academic grade of the students. The results obtained suggest that those who ran most programs per day did not save man-hours in "debugging by machine".

Hall, R. (2002). Learning and Online Knowledge Use. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Halpin, T. and Ritson, P. (1996). Entity Integrity Revisited. Australian Computer Journal 28(3): 73-80.

In the relational model,table rows must be identifiable by their primary key valuse. To enforce this condition, E F Codd includes the following entity integrity rule: 'No component of a primary key is allowed to have a missing value of any type'. This rule may, in practice, be too restrictive. We specify cases where entity identification is achieved even when the entity integrity rule is violated, and show how to implement these cases. However, since partially null primary keys may not always be desireable, we discuss ways to avoid them. The Rmap (Relational mapping) algorithm for mapping an ORM (Object-Role Modelling) conceptual schema onto a relational schema is extended to deal with such cases.

Halpin, T. A. (1989). Venn Diagrams and SQL Queries. Australian Computer Journal 21(1): 27-32.

SQL is widely used as a standard relational language for commercial database applications. While average users can easily formulate a wide variety of queries in SQL, there are other kinds of queries which they find very difficult to express. This paper discuses the use of logic diagrams to facilitate the construction and comprehension of a range of SQL query types dealing with set comparisons. Such queries are first pictured with the aid of Venn diagrams, and then mapped into SQL notation. Two mapping algorithms are discussed. Venn diagrams provide a systematic means of identifying query types amenable to these algorithms, as well as, opportunities for optimisation.

Hamblin, C. L. (1985). Computer Languages. Australian Computer Journal 17(4): 195-198.

The notation invented by the Polish logician Lukasiewicz in 1920 may be used for writing mathematical and logical formulae unambiguously without the use of brackets. This notation can be applied as the basis for a programming language for a computer system. The notation, Its use as a programming notation, and the principles for converting formulae In the notation to machine Instructions are described here.

Han, B. and Billington, J. (2002). Validating TCP Connection Management. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Hanlon, W. and Hamer, G. A. (1974). Planned Metrication of Computer Systems in a Large Steelworks. Australian Computer Journal 6(2): 78-81.

The introduction of the S.I. derived units of metric measurement is currently being implemented throughout the B.H.P. Group. In a company with heavy commitments to automated methods and computer based information systems in major production and commercial areas, it is essential that the change to metric standards be carried out smoothly. This paper outlines the data processing planning and involvement in the metric conversion effort at Australian Iron and Steel Pty, Ltd., the major subsidiary of B.H.P. Coordination of the data processing metric conversion by use of a project control system is also outlined.

Hannaford, M. R. and Blatt, D. W. E. (1993). Realisable Memory Management Algorithms. Australian Computer Journal 25(2): 70-81.

In this paper, a number of memory management paging algorithms have been developed making use of the BLI Transition model, a model of program behaviour based on the Bounded Locality Interval (BLI) concept. Although the model itself assumes lookahead knowledge of program referencing behaviour, the algorithms presents here do not, as they develop enough "on the fly" knowledge of the reference string to allow intelligent decisions to be made on whether a locality is to be kept memory resident, or released, creating page faults in the future. As well as making decisions of this kind, it is possible to anticipate actual future page faults, and issue requests for prepaging service. Two algorithms based on this principle are also presented. All the algorithms developed have been tested by simulation of a VM environment whilst executing a set of real reference strings. Their performance is compared to existing realisable algorithms as well as a near optimal lookahead algorithm.

Harding, D. A. (1972). Modular Programming - Why Not? Australian Computer Journal 4(4): 150-156.

The paper contends that current methods of programming, especially methods of controlling the programming task, have generally proved unsuccessful, and that Modular Programming provides a possible solution to this problem. However, various reasons exist why the technology is not universally adopted including a preponderance in the literature of references to the unsuccessful methods, misunderstandings of the technique and its application, and the problems A.D.P. management face in converting to a new methodology. Finally, it is suggested that the situation can be overcome only by a large research and education exercise embracing all A.D.P. personnel involved in programming.

Harper, S., Goble, C. and Stevens, R. (2001). Web Mobility Guidelines for Visually Impaired Surfers. Journal of Research and Practice in Information Technology 33(1): 30-41. First Page.

The 'Towel' project seeks to find solutions to problems encountered by visually impaired users when travelling in the World-Wide-Web (Web) by leveraging solutions found in real-world mobility. Visually impaired users find mobility on the Web particularly difficult because of the reliance of hypermedia on visual layout. Hypertext design and usability guidelines have traditionally concentrated upon navigation to facilitate this mobility; consequently other aspects of travel are neglected. This paper seeks to address these issues by extending current guidelines and design methods to include the real-world mobility concepts of orientation, memory, environment, preview and the purpose of the task at hand.

Harris, G. H. and Forster, J. J. H. (1993). Automation of the Crozzle. Australian Computer Journal 25(2): 41-48.

The Crozzle, a comples crossword variant, is described. The Crozzle consists of entering words from a given lexicon into an empty grid such that a total score based on, (i) the individual scores for the letters at which words intersect and (ii) the total number of words entered, is maximised, This process also determines the number and location of black squares in the grid. An algorithm, using depth first recursion and a 2-level look-ahead to generate solutions to the unconstrained crossword puzzle problem is modified and applied to the Crozzle. The solution scores generated are compared to the score of the solutions produced by humans. Three data sets are presented as benchmarks for future research efforts.

Harry, E. J. (1970). Storage CRT's in Graphic Computer Terminals. Australian Computer Journal 2(4): 156-159.

The relatively recent incorporation of Direct-View Bistable Storage CRT's in Graphic Computer Terminals has made terminals capable of high density alphanumerics and complex graphics available at a price comparable to alphanumeric only terminals which allows users to now consider graphic displays where cost was prohibitive in the past. This article will discuss the characteristics of DVBS, some of the more common approaches to generating both alphanumerics and graphics, some of the advantages and disadvantages of DVBS are compared to refreshed CRT terminals and several possible future developments.

Harvey, N. and Morris, J. (1996). NL: A Parallel Programming Visual Language. Australian Computer Journal 28(1): 2-12.

The dataflow programming model provides a simple way of expressing an algorithm which exploits all the parallelism available in a program. The challenge is to provide a sufficiently powerful programming system which exploits the low level parallelism while allowing the programmer to work at a high level of abstraction.

Havas, G. (1981). Hyperdisk, an Access Method for Remote Disk Devices. Australian Computer Journal 13(2): 64-65.

A method currently under development for accessing remote IBM-compatible disk devices from IBM-compatible processors is described. The method is transparent to the application programmer and utility user. It provides for data transfer over the Network Systems Corporation HYPERchannel which is the basis of the CSIRONET local computer network.

Hawke, A. N. and Marlin, C. D. (1988). Expert Systems in Crisis Management: Ambulance Dispatch. Australian Computer Journal 20(1): 1-9.

Crisis management concerns situations where a human operator must make rapid decisions in an environment in which incorrect decisions have severe consequences. This paper describes an experiment in the application of expert system techniques to a particular form of crisis management: the allocation of ambulances to requests in a metropolitan area. The ambulance coordinator's task is described and the implementation of an expert system to advise coordinators is outlined. OPS5 is used to code the coordinator's expertise and Pascal is used to perform calculations, to interact with the operating system and to handle databases of information about suburbs and ambulances, Testing the expert system is also described.

Hawryszkiewycz, I. T. (1978). A Formal Approach to File and Data Base Design. Australian Computer Journal 10(1): 28-36.

Many files and databases must now satisfy the requirements of more than one user. There is then a need for a formal approach to the design of such files and databases to facilitate a systematic examination of design alternatives and resolution of conflicts. Several approaches to formal design are defined and one such approach is described in detail. The approach commences with information analysis that results in a structure, which represents the inherent structure of the real world with minimum duplication. The information analysis is based on the use of the relational model. Successive refinements are then made to satisfy query requirements.

Hawryszkiewycz, I. T. (1980). Data Analysis - What are the Necessary Concepts. Australian Computer Journal 12(1): 2-14.

The paper considers the role of Entity-Relationship diagrams and functional dependence diagrams as models of enterprise semantics. It stresses the need for modelling semantics at the data element level and proposes functional dependence diagrams for this purpose. Its claim is that models at this level can be simply converted to data base schema. Semantics of enterprise concepts such as dependence, classification and role are then discussed. F-D diagrams are used to describe semantic models of these concepts; problems of representing these models by data base structures is considered in terms of maintaining semantic constraints and data base stability.

Hawryszkiewycz, I. T. (1981). Data Independence in Data Base Design. Australian Computer Journal 13(4): 114-121.

Data independence is discussed in the context of program stability following a system change. Data independence is first defined and limitations imposed by the architecture of contemporary database management systems and by the nature of data base changes outlined. Methods of overcoming the limitations are then discussed. These include both improvements in data base architecture and the use of standards in the design method. Emphasis is then placed on design methods, which improve data independence with contemporary database management systems. One class of such methods is then outlined and their ability to improve program stability given a range of data base changes discussed.

Hawryszkiewycz, I. T. (1981). Some Trends in System Design Methodologies. Australian Computer Journal 13(1): 13-23.

Criteria for effective design methodologies are defined and some design methodologies compared against these criteria. The criteria call both for disciplined set of integrated design stages as well as for techniques that link program and data base design in a semantically consistent way thus reducing the program complexity. Some shortfalls of existing methodologies in meeting these criteria are discussed and suggestions made for future development. Such suggestion includes calls for closer integration of program and data base design, and for the development of adaptable systems that allow designers to adapt the computer interface to the semantics of the user lever.

Hawryszkiewycz, I. T. and Walker, D. W. (1983). Application of Structured Design Techniques to Transaction Processing. Australian Computer Journal 15(2): 69-75.

The limitations of structured design in a transaction processing environment are discussed. In particular, a conflict between top down hierarchical control. Inherent in structured design, and the bottom level activation assumed in transaction processing is noted. Three alternative methods for resolving this conflict so that structured design reductions can be adapted to the transaction processing environment are then discussed.

Hedges, D. A. and Williams, W. T. (1981). ASYM: A Divisive Monothetic Classificatory Program for Binary Data. Australian Computer Journal 13(3).

A program for the monothetic divisive classification of binary data using the asymmetric Jaccard measure is described. The new program, ASYM, contains a sorting strategy based on group heterogeneity which is not group-size dependent but instead is particularly sensitive to species diversity. Comparisons with the group-size dependent program DIVINF indicate that for those ecological applications where species diversity is important ASYM can be expected to give the more useful result.

Hedrick, G. E. and Alexander, B. R. (1972). COROUTINE Programming in FORTRAN. Australian Computer Journal 4(2): 73-78.

This paper describes a preprocessor which allows a programmer to use coroutines in FORTRAN in a natural way. The preprocessor and its use are discussed in detail.

Heinz, S. and Zobel, J. (2002). Performance of Data Structures for Small Sets of Strings. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Hemer, D. and Lindsay, P. (2002). Supporting Component-Based Reuse in CARE. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Henderson-Sellers, B. (1992). Object-Oriented Information System: An Introductory Tutorial. Australian Computer Journal 24(1): 12-24.

The use of object-oriented techniques in computing and information systems development is likely to increase over the next few decades to become a new standard alongside structured techniques. Consequently information scientists and computer technologists need to become conversant with at least the basic ideas of the object-oriented philosophy. Those ideas are presented here in a form independent of the language of implementation. Examination of the underlying three concerns of encapsulation/information hiding, abstraction/classification and polymorphism/inheritance leads to consideration of the terminology of objects, classes and class-class interaction.

Henderson-Sellers, B. and Simons, A. H. J. (2000). The OPEN Software Engineering Process Architecture: From Activities to Techniques. Journal of Research and Practice in Information Technology 32(1): 47-68. First Page.

The 1997 OPEN process metamodel was the first fully documented software engineering process architecture for object-oriented projects, predating the Catalysis method, Select Perspective and the still emerging Rational Unified Process by a number of years. The OPEN process metamodel is based on a three-tier architecture, in which process Activities are broken down into a number of distinct Tasks; and each Task may be achieved through the application of a number of approved Techniques. This paper describes the relationships betwen the three layers of the OPEN process metamodel and shows how OPEN's Techniques contribute to a particular tailored process. As an exemplar, we describe Techniques relevant to late design and coding.

Herbison-Evans, D. (1983). Hidden Arcs of Interpenetrating and Obscuring Ellipsoids. Australian Computer Journal 15(2): 65-68.

The drawing of three-dimensional outlines of objects composed of ellipsoids is considered. Any outline may be obscured because either it is behind another ellipsoid, or it penetrates into another ellipsoid. The outline to be drawn is divided into arcs by the points where it intersects the outline or penetrates the body of an obscuring ellipsoid. Each arc is such that if part of it is hidden then it is all hidden. In order to discover which arcs are hidden, they mist be tested. This paper discusses the use of topology to reduce the number of arcs to be tested. The number drops from eight to three in the most complex case, and is halved in most of the other cases. The use of the topology is complicated by the unpredictable zero point of the outline. The testing scheme presented here accommodates this problem. It is encapsulated in a number of tables in the paper.

Herbison-Evans, D. (2001). Waltzing on a KDF9. Journal of Research and Practice in Information Technology 33(4): 310-314. First Page.

Herman, P. M. (1976). A Data Flow Analysis Approach to Program Testing. Australian Computer Journal 8(3): 92-96.

An approach to preparation of test data for programs is described which uses information automatically derived from the text of the program being tested. Two kinds of information are extracted, the adjacency matrix of the program, and an indication of how and where variables have been accessed. This information is combined to determine a set of "test paths" which are to be tested by the programmer. The programmer derives his own data to satisfy the test paths derived; while the system monitors the test runs to determine which paths are actually being covered. Experience in using the system is discussed.

Hext, J. (2001). B-Trees - A Simple Proof of their Space Utilisation. Journal of Research and Practice in Information Technology 33(4): 356-359. First Page.

Hext, J. and Hirst, S. (1982). The Formal Treatment of State Transition Tables - A Tutorial. Australian Computer Journal 14(1): 1-6.

This paper gives a tutorial presentation of the theory that underlies the construction and use of state transition tables for reading certain kinds of character sequences.

Hicks, B. W. and Andrews, C. J. (1976). Reduction of Latency in Serial Semi Conductor Memories. Australian Computer Journal 8(2): 47-50.

A method is presented by which reductions in latency in high density memory elements can be achieved. The theoretical basis of the methods is fully derived, and examples of its use are given. These show that with readily available devices, reductions in latency of up to 75% can be obtained over quoted latency for the device. With the particular commercially available device used in the current application it is shown that latency in a 256 bit serial memory can be reduced to as low as 25 microseconds.

Higgins, J. P. (1977). A Computer Program for Exploring the Homogeneousness of Randomly Sampled Categorical Data. Australian Computer Journal 9(3): 112-113.

This paper describes and ANSI FORTRAN program for exploring the homogeneity structure of randomly sampled sets of categorical data. The samples of each set should be from populations whose characteristics are described by a nominated set of binary categories. Each set is considered separately as a contingency table. An asymptotically chi-square statistic is used for hypothesis testing and to provide a dissimilarity measure. The program uses free-format input facilitated by means of key words.

Higgins, P., Richards, D. and McGrath, M. (2001). Intelligent Visualisation of Social Network Analysis Data. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Hill, R. J. (1973). Staged Introduction of Manufacturing Information Systems. Australian Computer Journal 5(3): 96-104.

This is a review paper which documents experience gained in several installations around Melbourne, mainly associated with manufacturing control systems. The experience has shown that many implementation problems are caused by attempting to install in one step systems which are too comprehensive. Also, detailed objectives are often frozen too early, before the users have really had sufficient experience to correctly specify their needs. This paper documents strategies which help avoid these problems in the manufacturing control area.

Hille, R. F. (1985). Binary Trees and Permutations. Australian Computer Journal 17(2): 85-87.

On the basis of depth-first traversals of binary trees one can define sixteen classes of tree permutations. Various relationships between them are established and it is shown that there are only four different classes. Finally, an explanation is given why the two classes of permutations containing no monotonically increasing and decreasing subsequences, respectively, of length three cannot be related to binary trees in this way.

Hille, R. F. and Higginbottom, T. F. (1983). A System for Visible Execution of Pascal Programs. Australian Computer Journal 15(2): 76-77.

This paper describes a system for the visible execution of Pascal programs, intended for use in computing laboratory classes for first year students. It is essentially a pre-processor, written itself in Pascal for portability. It inserts additional code into the user program to cause the display on the terminal screen of the current statement together with its line number in the source as well as the value of any variable that was changed as a consequence of executing that statement. Break points are set to enable the user to step through the Pascal code by executing one statement at a time. The preprocessor is embedded in a UNIX shell file to bind the whole system onto a package.

Hingston, P. F. (2002). Using Finite State Automata for Sequence Mining. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Hingston, P. F. and While, R. L. (2002). A Dynamic Communication Algorithm for Digital Halftoning. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Hirschheim, R. A. (1986). Participative Systems Design: User Experiences, Evaluation and Conclusions. Australian Computer Journal 18(4): 166-173.

In the past ten years there has been a dramatic surge in the development of new systems analysis and design methodologies, each claiming to be better than the others. This has led to considerable interest in methodology comparison and evaluation. One type of systems development methodology which continues to arouse interest and speculation, is the participative variety. There is, however, a number of unresolved issues about this type of methodology, e.g. how does it differ from traditional methodologies, how do those who have used it feel about its strengths and weaknesses, are there particular kinds of systems which can or cannot be developed participatively, and what are the problems with its use. These and other questions provided the motivation for embarking on a two-year study addressing user experiences with and an evaluation of participative systems design. The study has recently been completed and its findings are summarized in this paper. Four main conclusions emerge: users generally possess very positive feelings about participative systems design; it appears applicable for most systems development or technology introduction; it does not necessarily lead to fewer requests for system modifications; it is certainly not problem free. The paper offers some thoughts on the likely value of participative design and some observations about its use in systems development.

Hirst, F. and Hawryszkiewycz, P. (1980). Computer Elucidation of the Occurrence of Higher Odd Subharmonic Motion and Other Subharmonic Phenomena. Australian Computer Journal 12(3): 113-119.

A computer based investigation of the occurrence of higher odd subharmonic motion and other related phenomena has been undertaken. Further investigation of a non-linear differential equation exhibiting an odd subharmonic component in some solutions and an even subhaonic component in other solutions has been accomplished.

Hirst, S. C. (1989). SRA: A Program for Symbolic Regular Algebra. Australian Computer Journal 21(4): 151-161.

The paper presents a user overview, design philosophy and some applications of a program for performing symbolic computation in the domain of regular algebra. Our expression space extends the usual regular expressions to arbitrary systems of equations with special emphasis given to the transformations of simplification, differentiation and the construction of finite state machines. Simplification is described using the concept of a 'weakened' canonical form. The account of differentiation, which is an extension to the work of Brzozowski. Finds an economical way of differentiating arbitrary equation systems.

Hodaway, H. W. (1977). GINV, A Subroutine in ANSI Fortran for Generalized Matrix Inversion. Australian Computer Journal 9(4): 159-161.

A description is given together with some illustrative test results for a set of subroutines useful for orthogonalization and factorization of any matrix, with applications to linear least squares problems via the generalized Moore-Penrose inverse. The basis inversion algorithm is dealt with on a column by column basis, which may lend itself to non-linear applications, where progressive updating of columns is used to assist the rate of convergence. Precautions have been taken to minimise the introduction of errors due to accumulated round-off errors of the computer, and some illustrative examples have been tabulated to demonstrate the accuracy capabilities of the algorithm. All algorithms are in ANSI compatible FORTRAN.

Hoffman, D. and Strooper, P. (1994). Graph-Based Class Testing. Australian Computer Journal 26(4): 158-163.

In contrast to the explosion of activity in object-oriented design and programming, little attention has been given to object testing. Two tasks arise: (1) testing a base class C and (2) testing a class derived from C, assuming C has been thoroughly tested. We describe test inputs as traces; sequences of function calls. Testgraphs are used to specify the large number of traces typically required for thorough testing. A testgraph partially models the states and transitions of a class implementation. Testgraph transversal may be varied to produce different test inputs. Outputs are verified using an executable oracle: a class specifically developed to check output correctness. Surprisingly thorough testing is achievable with simple testgraphs and oracles. The key is designing the two together, to avoid inputs for which output checking is hard. In testing derived classes, we focus on reducing the cost of test development by reusing base class tests and test code. Testgraphs provide a convenient structure for such reuse. We illustrate our appoach using detailed examples.

Hogan, J. M. and James, P. C. J. (1997). Australian Approaches to Internet Content Regulation. Australian Computer Journal 29(1): 16-23.

Concern over access by minors to undesirable material over the Internet has led to a flurry of regulatory activity by Australian governments since 1993. This article examines these responses in the context of the existing law - focusing upon the development of appropriate legislative models for on-line services and content classification. Many of these approaches require some level of self-regulation through Industry Codes of Practice, and we examine the likely requirements of such codes, their role in limiting liability of service providers for the transmission of prohibited material, and the potential for legal and ethical breaches by computer professionals as a result of compliance with code provisions.

Holmes, W. N. (1974). The Social Implications of the Australian Computer Society. Australian Computer Journal 6(3): 124-128.

This paper notes the development of the Australian Computer Society, the discussion of its adoption of formal qualifications for entrance, and the problems encountered by the Society, and by overseas computer societies. The paper then questions the wisdom of basing a professional society on specific machinery, doubts the existence of a profession embraced by the Australian Computer Society, and suggests that social rather than professional objectives should be adopted by the Society. This document was prepared using the Edit and Script facilities of the Cambridge Monitor system running under CP67. The paper has been modified from its original form in response to comments from the Journal's referee, to whom the author is most grateful.

Holmes, W. N. (1977). The Major Tasks of Data Processing. Australian Computer Journal 9(1): 32-38.

This paper reviews the historical development of data processing, discerning three approximate decades of distinct evolutionary cycles. Each cycle is seen as forking, two contrasting styles of data processing forming and separating during the cycle. On this basis, a classification of the major general areas of data processing is suggested. For each decade, characteristic aspects are discussed and both the lines of development are described. Finally, some observations regarding the present decade and its requirements are given, and some predictions relating to the next decade and its prerequisites are made.

Holmes, W. N. and Stanley, P. M. (1984). An Interactive Package for Teaching EDP Audit. Australian Computer Journal 16(2): 54-58.

This paper briefly discusses Generalised Audit Packages and EDP audit education. A modest portable interactive EDP audit package was developed for basic EDP audit training based on microcomputers. This package is first described from the user's point of view and then some of the details and problems of implementation are reviewed.

Hong, S.-H. (2001). Visualisation of Symmetry in Graphs. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Hook, D. and Forward, K. (1995). Using KD-trees to Guide Bounding Volume Hierarchies for Ray Tracing. Australian Computer Journal 27(3): 103-108.

Ray tracing, a simple yet powerful technique for investigating complex environments and a standard method of accelerating the ray casting process has involved constructing bounding volume hierarchies which have required either the use of precalculated costs or creating them as part of the model construction. We propose a method using the kd-tree which will guide the construction of a bounding volume hierarchy as well as providing a method for its traversal by individual rays. By taking advantage of the tree structure's recursive nature we show how to construct an algorithm with very good performance characteristics which in typical real life cases is much more computationally efficient than previous methods. Results are presented using some standard ray tracing benchmarks.

Hopkins, J. L. and McDougall, A. (2002). Psycles of Change: Development and Implementation of Databased Curriculum Documentation. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Horn, K. A., Compton, P., Lazarus, L. and Quinlan, J. R. (1985). An Expert System for the Interpretation of Thyroid Assays in a Clinical Laboratory. Australian Computer Journal 17(1): 7-11.

This paper examines the application of Expert System techniques to interpretative diagnosis in the clinical laboratory. Described is a system that uses expert knowledge encoded as production rules to aid the interpretation of Endocrine diagnostic tests The system utilises the data: age, sex, source of sample, referring doctors comment and a set of laboratory results to produce diagnoses as accurate and elaborate as an expert clinician. The system runs on a PDP 11/23 running the TSX-Plus operating system. The programs are written in the 'C language.

Hou, J. and Zhang, Y. (2002). Constructing Good Quality Web Page Communities. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Houle, P. A. and Franta, W. R. (1975). On the Structural Concepts of Simula. Australian Computer Journal 7(1): 39-45.

Simulation is becoming an important technique for solving problems in many fields. Often, owing to an unfamiliarity of a particular language, an inertia develops which prevents many from using it. This paper is partially tutorial in nature and attempts to introduce the concepts, simplicity, and expressive power inherent in SIMULA to a wider audience. Therefore, we discuss the ways in which SIMULA encompasses the concepts and expressive power of other popular languages such as GPSS and SIMSCRIPT. We demonstrate the SIMULA constructions of general utility by calling attention to the scenario point of view for the conceptualization of simulation models.

House, R. (1998). Attributes: Giving the Programmer Control Over Static Type Checking. Australian Computer Journal 30(1): 20-29.

This paper introduces a concept called an attribute, which permits a wide range of seemingly unrelated ad hoc language design choices to be formally described by one simple language construct. Explicit recognition of the attribute concept, by giving the programmer the powers formerly possessed only by the language designer, allows them to tailor semantic characteristics of types to fit the problem at hand. This contrasts with the need in other languages either to put up with the closest near-miss among a set of predefined types provided by the language designer or to engage in a major class-building exercise.

Howarth, B. R. (1982). Review of Disk Scheduling Policies. Australian Computer Journal 14(4): 150-154.

In many computer systems, overall throughput is limited by the number of transfers per second between the disks and main memory. This article reviews techniques proposed in the literature for improving performance of a single disk drive. The methods of selecting the next request to be serviced from those waiting (i.e., scheduling policies) are the principal area studied. Results of a simulation confirm the analyses. The review shows that while scheduling policies more complex than FIFO offer improvements in average service time, these are not very great under normal operating regimes of most computers. Better improvement can often be gained by careful placement of data on the disk.

Huang, M. L. (2001). Information Visualization of Attributed Relational Data. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Huband, S. and McDonald, C. (2001). Using XML to Specify a Trace Format for MPI Programs. Journal of Research and Practice in Information Technology 33(2): 133-145. First Page.

Trace files have long been used to assist correctness debugging and performance debugging of parallel programs. With the advent of implementations of the Message Passing Interface (MPI) standard, parallel and distributed computing has become more common,and thus the need for quality debugging tools has increased. It is important that trace file formats be extensible, flexible and architecturally independent, the latter particularly if analysis is performed on a different platform to that which generated the trace. In this paper we propose a set of requirements for MPI-based trace libraries, and present a preliminary trace library, tracempi. An important contribution is that this trace format uses the Extensible Markup Language (XML),and XML Schema. By doing so, it is architecturally independent, well defined and easily extended.

Hughes, G. (1990). Computer Crime: The Liability of Hackers. Australian Computer Journal 22(2): 47-50.

One of the negative features of the emergence of computers has been the inevitable development of "computer crime". Whilst there are many crimes which can be committed with the aid o computers one of the most prevalent and potentially most concerning is the increased incidence of unauthorised access to computer systems. Because of deficiencies in traditional criminal laws, new legislation has been enacted or contemplated in all Australian jurisdictions, although the approaches adopted by the various States are far from consistent. This article examines the way in which the law has adapted to regulate the crime of unauthorised access.

Hunt, L. R. (1975). Error Detecting and Correcting Codes. Australian Computer Journal 7(2): 70-74.

This tutorial paper highlights an important area of application but one not well covered in literature. It studies the theory and methods of encoding information for data transmission so that error detection and correction is possible. Basic communication methods are discussed as background and are followed by a study of the principal coding systems. The use of redundancy for error detection, and in some cases error correction is then covered. The theory of cyclic codes and polynomials is treated in some detail. The paper concludes with a study of the Hamming code as a practical implementation of cyclic code theory.

Hutchens, R. and Singh, S. (2002). Bandwidth Reservation Strategies for Mobility Support of Wireless Connections with QoS Guarantees. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Iannalla, R. (1992). Designing 'Safe' User Interfaces. Australian Computer Journal 24(3): 92-97.

The development of any computing software system involves considerable effort on establishing a consistent user interface. Failure to do so will inevitably lead to low user productivity and dissatisfied users. When in the specification stage of a Software Engineering project, great detail must be made in the area of the system's User Interface. Most Software Engineering projects, by their nature, have a complicated interface and today's Graphical User Interfaces allow the Software Engineer to develop sophisticated and innovative front-ends. By following a few basic guidelines and suggestions, they can improve this interface for greater user satisfaction and wider acceptance.

Indulska, M. and Orlowska, M. E. (2002). On Aggregation Issues in Spatial Data Management. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Irwin, W. and Churcher, N. (2002). XML in the Visualisation Pipeline. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Isal, R. Y. K., Moffat, A. and Ngai, A. C. H. (2002). Enhanced Word-Based Block-Sorting Text Compression. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Itzstein, G. S. and Kearney, D. (2002). Applications of Join Java. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Jackson, B. J. (1970). Evaluating Programmer Workload. Australian Computer Journal 2(1): 22-26.

This paper discusses an approach to the problem of allocating programmers to programmes, so as to evenly and efficiently spread the workload and estimate how long it will take to write a given number of programmes.

Jamieson, J. (2001). Regulation of Medical Devices involving Software in Australia - an Overview. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

The Therapeutic Goods Administration (TGA) regulates the supply of therapeutic goods in Australia - including medical devices. Many medical devices are not programmable, electronic, or even electrical. However more devices are becoming programmable, and existing medical device software is becoming more complex. Currently in Australia, certain types of medical devices are subjected to extensive pre-market documentary evaluation by the TGA. However most devices have less scrutiny. It is proposed that medical device regulation in Australia will harmonise with the European Union Medical Device Directive. It is thereby hoped to: enhance requirements for many devices that are currently subject to few or no controls; reduce duplication for devices previously assessed by an overseas regulatory body; and to place increased emphasis on manufacturer quality and risk management systems and on post-market surveillance. The intention is to address the safety of medical device software in its environmental context, and as a part of the device as a whole.

Jamieson, R. (1982). Systems Development Data Base Audit - A DP Management Guide. Australian Computer Journal 14(1): 7-11.

This paper provides a guide for data processing management to understand the rationale behind audit involvement in the systems development process. Particular emphasis is paid to explanation of audit concerns arising as a result of the data base environment.

Janneck, J. W. and Esser, R. (2002). Higher-Order Petri Net Modelling - Techniques and Applications. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Jansen, E. E. (1975). Virtual Storage - A Review. Australian Computer Journal 7(1): 29-32.

This paper takes a closer look at some of the major aspects of Virtual Storage (or Paging, as it was originally known). A brief description of the principle of paging is given, followed by a review of a number of papers, published just prior to the recent advances made through the use of hardware paging features. The papers considered present results and opinions based on practical experiences and simulation models, and were written by leading authors in this field. There has been considerable publicity for this topic recently by some of the major computer manufacturers, yet little commentary is available in the technical press. This resulting paper then presents a guide to seeking an impartial appraisal of the subject.

Jarvis, C. L. (1971). A Method for Fitting Polygons to Figure Boundary Data. Australian Computer Journal 3(2): 50-54.

A method is described for fitting polygons of a small number of sides to figure boundary data. The technique determines a set of vertices and evaluates the adequacy of the fit by a least squares method. Examples are given from a particular image class and the utility of the technique is considered in relation to several processing problems of this class.

Jarvis, R. A. (1983). Growing Polyhedral Obstacles for Planning Collision-Free Paths. Australian Computer Journal 15(3).

Planning collision-free minimal length paths through an obstacle field to a goal arises naturally in robotic vehicle control. For obstacles and robotic vehicles which can be realistically represented by polyhedra, the task of discovering these minimal length paths can be mapped into a classical tree search problem (to which the A* algorithm can be effectively applied), by growing the obstacles to account for the physical size of the vehicle, which subsequently is itself represented by a single reference point. This paper explores a number of issues concerning collision-free paths for various modes of vehicle motion including combined translation and rotation in transit to the goal. For pure translation the method produces exact solutions; for combined translation and rotation, the solutions, though in the most part satisfactory, are not exact. Only examples in the plane are presented, although the methodology described can be readily extended into the third dimension.

Jarvis, R. A. and Creasy, P. N. (1977). Batch Submission, Demand Terminal and "Hands-on" Computing in a Computer Science Tertiary Education Environment. Australian Computer Journal 9(3): 114-117.

Whereas the conventional batch mode of processing student jobs for large classes at an introductory level may be technically efficient in terms of processor and peripheral equipment utilization, it is not difficult to argue that demand access provides a more effective computer science teaching environment, especially if a remote entry point can be provided inexpensively in the vicinity of teaching centres. A case can also be made for "hands-on" usage of a small in-house computing system in providing a comprehensive experience of a limited but complete computing system, particularly for Computer Sciences courses built around special peripheral instrumentation. These three different types of computing modes are compared through case study observations relating to actual teaching experience at the A.N.U. by Computer science academic staff. The logistic, economic and academic factors involved in determining which computing mode is best suited to which course is carefully examined. The rationale behind the development of Computer science facilities in relation to academic motivations is given, together with details of relevant courses.

Jayaputera, G. T. and Cheng, K. E. (1994). SOFTEAM: A Design History and Justification Maintenance Tool. Australian Computer Journal 26(4): 124-133.

Maintaining the design history and justification is still one of the problems in the software design process. The problem is exacerbated by the need to capture decisions in a meaningful manner, as opposed to textual description only. Furthermore, a better mechanism is required if a dsigner needs to backtrack to one of the previous design stages. This paper describes a formal representation model that can be used to capture design history and justifications, and presents how better backtrackings can be performed by utilising the representation. SOFTEAM is a prototype tool which has been developed based on the formal representation model presented here. SOFTEAM is able to capture the history of SDL-based design specifications evolution and design justifications that are made during a design process.

Jeffery, D. R. and Lawrence, M. J. (1990). Guest Editor's Introduction: Current Research Directions in Information Systems. Australian Computer Journal 18(4): 157-158.

Jeffery, R. and Low, G. (1997). Function Points and their Use. Australian Computer Journal 29(4): 148-156.

This paper discusses the research program in CAESAR which has been directed at either evaluating the function point metric or investigating its use in software engineering management over the last ten years. The paper summarises the results of a number of studies in terms of (1) the validity of the function point metric, (2) a comparison of different function-based sizing techniques, (3) the use of function points in productivity measurement (4) the use of function points in tool assessment, and (5) the use of function points in cost estimation. Through this analysis, we provide the reader with a summary of the strengths and weaknesses of the function points measure as well as showing support for the direction that the definition of the function point metric has taken over recent years.

Jeffery, R. and Zucker, B. (1999). The State of Practice in the Use of Software Metrics. Australian Computer Journal 31(1): 9-16.

This paper presents the results of a survey of members of the Australian Software Metrics Association which was carried out to establish the state of practice of software metrics in Australia. The mailed survey asked for data on the extent of collection of metrics in ten categories covering software size, organisational characteristics, effort, quality, structure, productivity and resources. It was found that there is very little use of product structure metrics but high use of software size, effort, and quality measures. There is a suggestion in the data that the metrics collected are focussed at the project level rather than at the process level, suggesting that metrics for project control are common but metrics for process improvement are not.

Jessup, A. M. and Wallace, C. S. (1968). A Cheap Graphic Input Device. Australian Computer Journal 1(2): 95-96.

A cheap readily-available office machine designed to cut facsimile stencils from any kind of printed or drawn sheet has been modified to provide a graphic input to a KDF9 computer. The modifications are simple and do not interfere with the normal use of the device. The graphic input gives a resolution of about 0.005 inch in each direction over an area of 12 x 9 inches but has no grey scale. The device is interfaced to the computer via a flexible input buffer previously constructed for other purposes. Scanning of a sheet takes about eight minutes, but as the input data is transcribed to magnetic tape as a time-shared monitor function, less than 5 seconds of CPU time is required per picture.

Jiang, H., Lu, H., Wang, W. and Yu, J. X. (2002). Path Materialization Revisited: An Efficient Storage Model for XML Data. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Jin, J. S. and Wang, R. (2002). The Development of an Online Video Browing System. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Johnson, C. W. (1978). Simula 67 Through Run-Time Structure. Australian Computer Journal 10(2): 60.

Simula 67 lacks an adequate description of its semantics in simple terms. The report described here gives one as a branching stack of activation records and uses it to describe the effects of the "resume" and "detach" control transfers. A simple implementation of the language is seen to depend on restrictions imposed by the designers on top of their use of block structure.

Johnston, S. and Acquaah-Gaisie, G. (2001). Economic development via the Net in Oceania. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

The Internet is permeating our lives because of its power. This brings obvious social and economic value. Less obvious are the social and economic hurts. The Net's reach is global, but Net access is far from global; and as the IT caravan rolls on, stragglers slip further behind. However, the Net is a cheap power just made for isolated people, and thus it offers access to an unprecedented equality of opportunity. Women have equal access. But the already poor do not. Equity here raises questions of human rights, ethics, the profession-al standing of the computer industry, good business, and develop-ment aid. So the Net can both amplify- and bridge the divide between rich and poor. Wealth is a function of relative purchasing power, which itself is a complex product of money and also of how we use it. Left to itself therefore IT makes some people poorer and adds new social tensions. This paper seeks programs which use the Net as a spearhead to bridge social and economic gaps across the Pacific Islands. It outlines some possibilities and issues, points of UN leadership and UN weaknesses, the major stake-holders, and local priorities. Antipodean Estonia has taken two great steps - a computer for every twenty pupils, and a guarantee of Net access to every citizen. That is a model for isolated South Pacific islands.

Johnston, S. W. and Acquaah-Gaisie, G. A. (1999). Computers and Human Rights: Toward a UN Code of Computer Ethics. Australian Computer Journal 31(3): 94-98.

Information Technology disseminates all human thought, helpful and mischievous, and develops the world culture. United Nations law on information is thin and needs computer ethics input. The Internet is manageable only by global laws. This paper considers human rights to free speech, privacy, reputation, and development and recommends a UN code of computer ethics. Internet service providers could suggest editorial standards for users and compensate people injured via their service. That burden might spur offender-tracing safeguards. Good moralists will build morale and make computer ethics a happy art.

Jones, A. J. (2002). Integration of ICT in an Initial Teacher Training Course: Participants' Views. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Jones, J. (2002). DVB-MHP/JavaTV Data Transport Mechanisms. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Jones, P. D. (1967). Computer Science Education In Australian Universities. Australian Computer Journal 1(1): 37-43.

Formal undergraduate and graduate computer science courses are just beginning to take shape in most Australian universities. It appears immensely important to these early formative years to promote as much wide-scale interest and discussion in order to help formulate the best possible courses and define the role of the computer science department, particularly in its relationship to other bodies. The paper proposes a possible course structure suited to the Australian scene and discusses important related issues. In the past computer teaching and research have proceeded independently in the various universities, with little impact on matters outside the university sphere of activity; ways for improving this state of affairs are suggested in the paper.

Juliff, P. (1980). Program Control by State Transition Tables. Australian Computer Journal 12(4): 146-152.

The use of state transition tables as a means of program control provides a programming methodology which is easy to construct, leads to concise source code and allows for ease of maintenance without alteration to procedural code.

Juliff, P. L. (1978). Effective Structuring of COBOL Programs. Australian Computer Journal 10(2).

Structured programming has been with us for some time and we are all aware of its precepts. This paper presents means by which the structure of a program may be determined and implemented in a COBOL program and the effects of the interaction between that structure and a virtual storage environment.

Kao, T.-W. and Horng, S.-J. (1996). The Power of List Ranking on a Reconfigurable Array of Processors with Wider Bus Networks. Australian Computer Journal 28(4): 138-119.

This paper makes an efficient improvement of processor complexity for computing list ranking and some related problems on a reconfigurable array of processors with wider bus networks by increasng the bus width between processors. Usually, the bus width of the system bus requires log N-bit for a parallel processing system with N processors; instead of using log N-bit, the bus width of the system bus of a reconfigurable array of processors with wider bus networks is assumed to be O(N*)-bit where * is a constant and *>=1. Based on such an archicture and a base-n (n=N*) number system technique, two constant time basic operations are first introduced for computing the prefix modular n and prefix division n of an N-bit binary sequence using N processors. Then, many fundamental algorithms can be solved in constant time on this newly created machine using N 1+* processors. These algorithms include the prefix sum of N integers problem, the unweighted (or weighted) list ranking problem, the Euler tour related problems and tree recursion related problems, respectively. Note that the list two categories of problems can be reduced to the list ranking problem. If this problem can be solved efficiently, then both of the others can also be solved efficiently. Another contribution of this paper is that the execution time of the proposed algorithms is tunable by the bus width of the system bus installed. That is, the wider the system bus installed, the faster the algorith obtained.

Karoly, G. (1977). Real-Time Systems at the Victorian TAB - An Historical Review. Australian Computer Journal 9(1): 11-16.

A description is given of this application area for real-time systems, giving reasons for using computerised wagering systems, the basic functions of such systems and the system design requirements. The history of the computer system at the TAB of Victoria is traced from its beginning in 1965 to the present. Changes in the design concepts of wagering systems are described and related to experience with the TAB system.

Karoly, G. and Marquet, J. W. (1969). A Mathematical Basis for a Terminal Network Cost Minimisation Strategy. Australian Computer Journal 1(5): 251-257.

By means of a simplified model a mathematical analysis is presented of the problem of network cost minimisation for the situation when several hundred terminals distributed over urban and suburban areas are to be connected to a central processing point.

Karunaratne, S. and Yan, H. (2001). A Fuzzy Rule-Based Interactive Methodology for Training Multimedia Actors. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Kaunitz, J. (1982). A Descriptive Model for the Architectural Design of Information Systems. Australian Computer Journal 14(3): 91-98.

It is proposed that, in selecting an information system for an organisation, the procedure followed should be similar to high-level design procedures employed in building architecture and engineering. Using a simple descriptive model, analogous to architectural sketches and plans, and an operational description of the proposed system, the system designers and client management should jointly resolve, at the outset, the major issues which determine the fundamental nature of the information system to be implemented. This paper explores and develops a model for the structural description of information system environments which is both application and implementation independent. Brief reference is made to the operational description.

Kaunitz, J. and Van Ekert, L. (1981). Data Base Backup - The Problem of Very Large Data Bases. Australian Computer Journal 13(4): 136-142.

For the users of very large data bases, traditional data base backup procedures imply unacceptable operational costs in terms of time and resource utilisation. This tutorial paper reviews the traditional approach and examines its performance implications to very large databases. A range of measures is then reviewed whereby the efficiency of backup procedures may be improved and operational problems alleviated. These measures fall into two categories: enhancements to system utilities during backup and recovery and considerations relating to application system design.

Kay, J. (1985). Expert Systems in Education. Australian Computer Journal 17(1): 33-37.

This tutorial paper presents an overview of uses for knowledge-based Expert Systems in education. It covers applications of Expert Systems in various roles: tutor, tutee and tool. A range of existing systems is described in order to give the flavour of current and potential uses.

Kayed, A. and Colomb, R. M. (2002). Using Ontologies to Index Conceptual Structures for Tendering Automation. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Keedy, J. L. (1977). An Outline of the ICL 2900 Series System Architecture. Australian Computer Journal 9(2): 53-62.

The system architecture of the ICL 2900 Series is outlined informally. Its central feature, the virtual machine concept, is described and related to virtual storage, segmentation and paging. The procedural approach is then discussed and its implementation by a stack mechanism is described. Further sections outline the protection mechanisms, and the instruction set and related features. Finally the virtual machine approach is related to global system activities. This paper has been written such that it may be of interest to readers without a specialist knowledge of computer architecture.

Keedy, J. L. (1978). On Structuring Operating Systems With Monitors. Australian Computer Journal 10(1): 23-27.

This paper considers whether Hoare's monitor proposal for structuring operating systems could usefully be applied in the design of substantial operating systems for medium to large computers. Attention is drawn to problems which might arise in terms of the structural form of monitors, the approach to resource scheduling, and the monitor approach to synchronisation and process scheduling. An appended note considers the related technique proposed by Wirth in the Modula language.

Keedy, J. L. (1979). On the Specification of Software Subsystems. Australian Computer Journal 11(4): 127-132.

This paper proposes that specifications for each information-hiding subsystem (module) of a large software system be expressed in a language closely resembling the high level programming language which will be used to implement that subsystem, and illustrates how such a technique can be developed, using Parnas' state machine specifications as a basis. Advantages of this technique, mainly practical and including the ease of processing specifications and incorporating them into design data-bases for subsequent use by designers, implementors, and compilers, are outlined in the concluding section.

Keedy, J. L. (1980). On the Exportation of Variables. Australian Computer Journal 12(1): 23-27.

Exportation of variables from program modules has recently become "respectable", despite the fact that this contravenes the information-hiding principle. After illustrating why this has happened. The paper re-emphasizes the dangers which it raises, and then proposes two solutions which might be applied. The first involves a novel view of high level languages and their compilers, and the second involves a novel view of procedure call mechanisms at the hardware level.

Keedy, J. L. (1980). Virtual Memory. Australian Computer Journal 12(2): 63.

Keedy, J. L., Menger, G. and Heinlein, C. (2002). Support for Subtyping and Code Re-use in Timor. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Keedy, J. L. and Richards, I. (1982). Software Engineering View of Files. Australian Computer Journal 14(2): 56-61.

The paper takes a fresh look at files, and argues that meny benefits can be derived by treating them as information-hiding modules rather than free-standing data structures. A case is made for a hierarchical structure which includes both access routines and semantic routines. A powerful protection mechanism based on semantic routines is discussed.

Kemeny, L. G. (1972). The Monitoring, Identification and Control of Nuclear Power Systems with an Online Computer. Australian Computer Journal 4(4): 170-176.

This paper describes the "SNEDAC" data acquisition system of the school of Nuclear Engineering, University of New South Wales. The School, in collaboration with the Australian Atomic Energy Commission, will use this computer for statistical measurements on reactor systems, reactor diagnostic and control studies, and systems optimisation. The design and operational characteristics of "SNEDAC" are discussed. The system consists essentially of a low-speed data logging section presently scanning twenty channels and outputting the information at a rate of seventy-five characters per second on a strip printer and a paper tape channel operating in parallel. The low-speed logger is synchronised and interfaced with the high-speed section which incorporates a minicomputer and a nine-channel incremental tape deck. This part of the system currently operates at 30,000 Hz and it is anticipated that this performance will be eventually improved with the addition of an FM recording system and very high speed analogue to digital conversion equipment. The diagnostic and control functions of the system are facilitated by the provision of a separate, hard-wired, dynamic analysis section interfaced with the computer and containing a pseudo-random noise generator and a digital correlator. The execution of diagnostic and control functions is based on programmed control and logic instructions and time series analysis algorithms, in particular the utilisation of correlation and spectral analysis. The software philosophy and the numerical algorithms utilised for on-line operation are described.

Kemp, E. A. (1988). Encryption in Electronic Funds Transfer Applications. Australian Computer Journal 20(4): 170-177.

To protect the data sent through financial networks, encryption and message authentication are essential. Both the PIN and the transaction details are at risk in ATM and EFTPOS systems. The Data Encryption Algorithm can be used both to encrypt PINs and generate a message authentication code that can be verified by the receiving party. Since the same key is required for both encryption and decryption, there is the problem of distributing it safely to both ends of the communication line. This difficulty can be resolved either by using public key cryptography or by implementing the Transaction Key scheme proposed in Australia.

Kemp, R. H. (1992). Intelligent Computer Assisted Instruction: a Knowledge-Based Perspective. Australian Computer Journal 24(4): 121-129.

Research into using the computer for teaching has been in progress since the 1960s but, except for a few specific areas, there has been a distinct lack of success. Over the years various new approaches have promised to solve some of the outstanding problems. In this article the impact of knowledge-based methods on the development of teaching systems is considered.

Kennedy, W. K. and Peters, T. M. (1975). High Quality Image Recording and Display Using a Small Hybrid Computer. Australian Computer Journal 7(2): 26-28.

Numerous applications of computer image processing require devices which encode and decode pictures with very little distortion, in order that the results of the computer processing may be evaluated without having to take into account the performance characteristics of the image input and output devices. A scanner which is capable of digitising an image up to 1000x1000 picture elements, with a dynamic range of 30db, is described. To ensure adequate dynamic range in the displayed image, a facsimile (wire-photo) machine is used. The manner in which such devices may be controlled by a small hybrid computer is described. A comparison is made between images reproduced using the facsimile and using conventional techniques of line-printer overprinting.

Kewley, D. J. (1981). A Comparison Between PASCAL, FORTRAN and PL/1. Australian Computer Journal 13(1): 27-28.

The PASCAL language implementation on the Defense Research Centre Salisbury IBM3033 is tested for program CPU execution times and compared with similar programs in FORTRAN and PL/1. The results show that the relative execution times are similar to those measured on CDC and UNIVAC machines and that the PASCAL language programs were usually slower than optimised FORTRAN while being faster than PL/1 for some of the tests.

Khandelwal, V. K. (2000). What the Australian CEOs Want from IT. Journal of Research and Practice in Information Technology 32(3/4): 151-167. First Page.

This paper discusses the results of a Critical Success Factors (CSFs) study carried out to determine the key IT management needs of Australian CEOs. In the past several studies to determine the IT management needs have been carried out, but they have aimed mostly at the IT managers, not the CEOs. This study fills this gap, and by comparing the CSFs of the CEOs with those of the IT managers shows the areas of misalignment in the management of IT in Australian enterprises. It is concluded that to achieve ongoing alignment the CEOs and senior executives need to gain management level understanding of IT. But perhaps even more important is for IT managers to develop a business oriented perspective for the success of their enterprise.

Kidman, B. P. (1981). On Understanding Binary Research. Australian Computer Journal 13(1): 7-12.

A formal approach to specifications and verification leads to the identification of underlying basic search schemes and hence to precise understanding of different versions of binary search including uniform binary search. Programs based on these schemes are simple, general and adaptable.

Kim, J., Feng, D. D. and Cai, T. W. (2001). A Web Based Medical Image Data Processing and Management System. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS.

Kim, J., Feng, D. D., Cai, T. W. and Eberl, S. (2002). Integrated Multimedia Medical Data Agent in E-Health. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Kim, J., Feng, D. D., Cai, T. W. and Eberl, S. (2002). A Solution to the Distribution and Standarization of Multimedia Medical Data in E-Health. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Kim, M. H. and Hwon, Y. R. (1989). SPEX: A Method for Specifying the Dynamics of Structured Specifications Including Control Information. Australian Computer Journal 21(1): 19-26.

We suggest a new approach to the dynamic aspects of structured specifications, in which data flow diagrams are considered as stream processing specifications and data dictionaries as data generators. In our approach the correlation between data items and processes which transform them is clearly revealed, and the process description conforms to the data flow diagrams. Control information implicitly contained in structured specifications may also be deduced from the data generators. In order to provide a formalism for representing structured specifications in a machine readable form, we have defined a language SPEX. It uses a single conceptual framework, the stream, for the uniform representation of each component of structured specifications. A particular emphasis is on the specification of data dictionaries. Data dictionaries represented in terms of data generators facilitate automatic derivation of control information from SPEX specifications.

Kimelman, D., Leban, B., Roth, T. and Zernik, D. (1995). Dynamic Graph Abstraction for Effective Software Visualisation. Australian Computer Journal 27(4): 129-137.

Graphs are used extensively in software visualisation to represent both static aspects of software structure and dynamic aspects of execution- time behaviour. However, for realistic subject software systems, there are far too many nodes and edges in the displayed graphs to be comprehensible to an end user. Further, for presentation of dynamics, continual change and redisplay of such large graphs is too demanding for conventional workstation computational resources. This paper poses the problem of "reduction" or "abstraction" in dynamically changing graphs representing software systems, and proposes a combination of techniques that can be used to reduce the visual complexity of a graph, without obscuring the significant information that it was meant to convey. The abstract graph can be comprehended more readily and it changes far less frequently than the full graph. As well, when the abstract graph does change, it requires far less computation for layout and redisplay. These abstraction techniques are illustrated by way of examples showing their use in systems for visualisation of object-oriented and multi-layer software systems.

King, D. W. (1971). A Digital Processing System For Seismic Array Data. Australian Computer Journal 3(4): 178-181.

The Warramunga array, Northern Territory, provides seismic data in FM form on magnetic tape. The features of both the recording and playback installations which influence the subsequent digital data processing are described. The development of software to implement a digital processing method in which seismometer channels are summed, after steering delays have been inserted to allow for the arrival of energy at non-vertical incidence, is discussed in detail.

King, J. and Bond, T. (2002). Parents' and Students' Satisfaction with the Use of Information Technology in Government Schools in Queensland, Australia. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Kitsuregawa, M., Toyoda, M. and Pramudiono, I. (2002). WEB Community Mining and WEB Log Mining: Commodity Cluster Based Execution. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Klobas, J. E. and McGill, T. (1993). Computing Professionals and Information About Developments in Information Technology. Australian Computer Journal 25(4): 149-158.

This paper reports the results of a survey of the methods used by computing professionals to keep up to date with developments in information technology. Information channels representing a range of formats and sources of information are studied. The results support the contention that accessibility of an information channel is a more influential factor than the perceived importance of the channel in choices of methods used to keep up to date. Exploratory multivariate analyses indicate the existence of information gathering strategies, and that there is a relationship between strategies and difficulty experienced in keeping up to date.

Koukouvinos, C., Lappas, E., Mitrouli, M. and Seberry, J. (2001). On the Complete Pivoting Conjecture for Hadamard Matrices of Small Orders. Journal of Research and Practice in Information Technology 33(4): 298-309. First Page.

Kowalik, J. (1967). A Note on Nonlinear Regression Analysis. Australian Computer Journal 1(1): 51-53.

A general analysis of a nonlinear regression problem, utilizing a number of Gauss methods has been performed. These methods have been demonstrated to be unreliable, in that they do not always lead to a solution and the reasons for their failure have been given. It has been suggested that the variable metric method of Davidon, Fletcher and Powell is a more satisfactory technique, since its use always gives convergence. There are provided numerical examples which illustrate the relative merits of the Gauss and the variable metric methods.

Krishnan, P. (1994). Specification of Schedulers Using the Modal-mu Calculus. Australian Computer Journal 26(2): 42-49.

In this paper we show how certain types of schedulers can be specified using the modal calculus. We specify processes in CCS and show that scheduled processes satisfy the behavioural constraints imposed by the schedulers. We use simple examples and the CWB to demonstrate how automatic verification of systems can be carried out.

Kristensen, L. M., Mitchell, B., Zhang, L. and Billington, J. (2002). Modelling and Initial Analysis of Operational Planning Processes using Coloured Petri Nets. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Kulkarni, D. and Stumm, M. (1995). Linear Loop Transformations in Optimising Compilers for Parallel Machines. Australian Computer Journal 27(2): 41-50.

We present the linear loop transformation, framework which is the formal basis for state of the art optimisation techniques in restructuring compilers for parallel machines. The framework unifies most existing transformations and provides a systematic set of code generation techniques for arbitrary compound loop transformations. The algebraic representation of the loop structure and its transformation give way to quantitative techniques for optimising performance on parallel machines. We discuss in detail the techniques for generating the transformed loop and deriving the desired linear transformation.

Kummerfeld, R. J. and Lauder, P. R. (1981). The Sydney UNIX Network. Australian Computer Journal 13(2): 52-57.

A computer network has recently been established within and between the campuses of the University of Sydney and the University of New South Wales. The network provides a virtual circuit facility for remote terminals and a file/mail transfer facility. The machines participating in this network all run the Unix operating system. The network software evolved out of a desire to allow the system maintainers and developers to cooperate more closely.

Kurniawati, R., Jin, J. S. and Shepherd, J. A. (1997). Techniques for Supporting Efficient Content-based Retrieval in Multimedia Databases. Australian Computer Journal 29(4): 122-130.

This paper presents a brief survey of the current state of the technology used in supporting efficient content-based retrieval in index-based multimedia databases that use feature vectors to represent multimedia data. One of the main obstacles in performing efficient content-based multimedia retrieval is the high-dimensionality of the feature vectors used to characterise the data. Previous surveys on multidimensional access structures tried to cope with this diversity but tended to ignore the issues telated to high dimensionality of the feature space. This survey strives to give an overview of the techniques available to deal with such high dimensional spaces. The key properties of the most often used dimension reduction techniques will be compared, followed by a discussion of the multidimensional access structures that can deal with a higher dimensional space. Algorithms for supporting content-based query processing using these multidimensional access structures will also be evaluated.

Lai, R. (1996). Extending PROTEAN with the Partitioning Method. Australian Computer Journal 28(4): 121-127.

Reachability Analysis (RA) is the most popular protocol verification technique as it can verify a number of protocol properties, like deadlock freeness, livelock freeness and boundedness; and it can be easily automated. However, it is also very well-known that the state space explosion problem of RA limits its use in complex situations. The usefulness of existing verification tools in verifying complex protocols is very much restricted by this problem. Various approaches have been proposed to tackle the problem; and, so far, there have been very rare reports on how these approaches can be implemented. Without actually incorporating these techniques in a verification tool, the proposed methods remain theoritical. This paper describes the extension of a proven computer-aided verification tool, PROTEAN, to include the partitioning method in order to help relieve the state space axplosion problem.

Lai, R. and Lo, A. (1995). An Analysis of the ISO FTAM Basic File Protocol Specified in LOTOS. Australian Computer Journal 27(1): 1-8.

This paper describes the use of LOLA to verify the ISO FTAM (File Transfer, Access and Management) protocol and discusses the analysis of its behaviour using its utilities. LOLA is a computer aided analysis tool developed by the Madrid University of Technology, Spain. The Formal Description Technique used by the tool is LOTOS. It performs LOTOS to LOTOS transformations; the transformations are expansion, parameterised expansion and internal action removal. After applying these transformations to the LOTOS specification, deadlocks and livelocks can be analysed on the expanded form. LOTOS specifications can be tested by generating a test process; protocol behaviour can then be studied using the test results, and compared to its service specification. The protocol properties that can be analysed using LOLA utilities are deadlock and livelock freeness, and termination. Finally, a comparison is made with the previous verification work performed on FTAM using Petri Nets.

Lakos, C. and Sale, A. (1978). Is Disciplined Programming Transferable and is it Insightful? Australian Computer Journal 10(3): 87-97.

This paper examines the disciplined programming methodology of E.W. Dijkstra which advocates the development of correctness proofs simultaneously with writing a program, (if not before) in the context of two problems which faced the authors recently. The paper applies the thought processes advocated by Dijkstra to these problems and indicates the insight that the authors gained from this. In both cases algorithms new to the authors were derived, and the properties of these are also examined. The paper should be interesting to those concerned with increasing the effectiveness of programming, for it demonstrates that the techniques advocated by Dijkstra are indeed transferable to other programmers, and that this transfer yields better insight into the activities we call programming.

Lakos, C. A. (1988). Including an Explicit Memory Model in a Machine Description. Australian Computer Journal 20(1): 10-18.

This paper argues for the inclusion of an explicit memory model in machine descriptions used for retargetable code generation. The widespread approach of leaving the model implicit though parameterised at certain key points, is seen to be excessively limiting. By contrast, the inclusion of an explicit model allows for the elegant expression of several otherwise awkward machine features, including limited span branches, the presence of hardware stacks and memory segmentation even at the machine code level.

Lamp, J. (2001). The Code Red Epidemic: a Case Study. Journal of Research and Practice in Information Technology 33(3): 263-266. First Page.

An analysis of log files from an immune World Wide Web server was used to discover the patterns of infection from the Code Red worm variants. Analogies are drawn to biological systems. The need for protection is commented on.

Lance, G. N., Milne, P. W. and Williams, W. T. (1968). Mixed-Data Classificatory Programs III - Diagnostic Systems. Australian Computer Journal 1(3): 178-181.

Users provided with a computer classification, or an ordination derived from the initial inter-element measures obtained from such a classification, commonly require information concerning the relative magnitudes of the contributions of the original attributes to the final classification or ordination. Two diagnostic programs are described which extract this information in a convenient form.

Lance, G. N. and Williams, W. T. (1967). Mixed-Data Classificatory Programs I - Agglomerative Systems. Australian Computer Journal 1(1): 15-20.

The raw data for classification are frequently "mixed", in that they may include qualitative, multi-state, ordered and/or continuous quantities in the same matrix, which may also contain a relatively high proportion of missing or "inapplicable" entries. The problem of processing such data are examined, and existing computer programs critically compared. A new system, based on information statistics, is described.

Lance, G. N. and Williams, W. T. (1968). Mixed-Data Classificatory Programs II - Divisive Systems. Australian Computer Journal 1(2): 82-85.

The problems of developing divisive classificatory programs for mixed data are critically examined, and it is shown that their solution requires two new algorithms. Suitable algorithms are proposed, and computer programs embodying them outlined.

Lance, G. N. and Williams, W. T. (1975). REMUL: A New Divisive Polythetic Classificatory Program. Australian Computer Journal 7(3): 109-112.

The need is established for a polythetic divisive classificatory program capable of handling a mixture of attribute-types and making provision for missing values. A reallocation feature is included and this is applied after each division, when individuals may move between the groups just formed, and at the end after the required number of groups has been obtained, at which stage any migration is allowed. Earlier programs of this type are reviewed, and it is submitted that even the most successful of these are to some extent limited in their application. The requirements for a general-purpose program are summarized. A new program REMUL. Is described which appears to meet these requirements; it has already been used successfully on a wide variety of data.

Lance, G. N. and Williams, W. T. (1977). Attribute Contributions to a Classification. Australian Computer Journal 9(3): 128-129.

This paper describes a method for ranking the attributes, used in a numerical classification, so that their contribution to the grouping is displayed. The three most common types of attributes, qualitatives, multistates and numericals can be incorporated in this ranking.

Lance, G. N. and Williams, W. T. (1979). INVER: A Program for the Computation of Distance Measures Between Attributes of Mixed Types. Australian Computer Journal 11(1): 27-28.

A method for the calculation of inter-attribute distance measures is described. The attributes are, of course, used to describe a set of individuals. The method can be applied in the most general case when any or all of the attribute types, binary, numeric, ordinal and multistate nominal are present. Various precautions have to be taken so that a consistent set of measures is obtained, these are carefully described. Other measures could be used but quite extensive testing on real data has shown that those proposed are best in real-life situations.

Land, A. (2001). A Network Flow Method for Determining the Gradient of Roads. Journal of Research and Practice in Information Technology 33(4): 294-297. First Page.

Lane, M. S. and Cavaye, A. L. M. (2000). Integrating Web and Database Marketing: Australian Study of Direct Marketing Firms. Journal of Research and Practice in Information Technology 32(3/4): 168-180. First Page.

The advent of web based electronic commerce has created numerous opportunities for marketing professionals to enhance current marketing practices by integrating the interactive nature of the web with database marketing. The challenge for IT professionals is to align IT with web site strategy in order to utilise the potential of the database marketing to enhance interaction and personalised communication with the customer. Three direct marketing firms were investigated to provide real insights into the integration of database marketing with the Internet and to compare current knowledge with practice.

Lawrence, M. J. (1979). The Computer Data Base Decision 1989. Australian Computer Journal 11(1): 13-20.

The decision to implement a data base cannot be treated as a technical software option and left to the software boffins to make. Its far reaching management implications make it vital that senior management be involved in and participate in the decision. The implications of this decision are outlined and the paper presents what is believed to be the minimum degree of knowledge necessary for the non-computer executive to be able to contribute meaningfully to the question "Should we implement a data base?"

Lawrence, M. J. and Jeffery, D. R. (1983). Commercial Programming Productivity - An Empirical Look at Intuition. Australian Computer Journal 15(1): 28-32.

Two empirical studies have been carried out to examine a number of hypotheses related to the effects of organisation and technical factors on programming productivity. In the first study a comparison of three organisations was carried out, while in the second study, data from twenty-two organisations was analysed. The first revealed similar programming time equations for each organisation, with lines of code having the highest correlation coefficient with programming time. In both studies a number of counter-intuitive results were observed. For example, the data indicated that programmer experience, programming methodology or on-line testing had very little impact on productivity.

Le Fevre, A. M. and Pattison, E. M. (1986). Planning for Hospital Information Systems Using the Lancaster Soft Systems Methodology. Australian Computer Journal 18(4): 180-185.

Planning for the introduction of information systems into hospitals and health care institutions under the aegis of the Health Department of Western Australia is described. Checkland's "Lancaster Soft Systems" Methodology was used as the basis of information planning, to allow for a socio-technical perspective of the state-wide requirement for integrated hospital management information systems. An information planning study carried out at a major metropolitan non-teaching hospital is used to illustrate the application of the soft systems methodology at a high level of analysis. The methodology not only allows, but requires, user participation to determine information needs based not on current procedures, but on a conceptual view of required activities which fulfil the organisation's goals and objectives.

Le, Q. and Le, T. (2002). Where Does the Superhighway Lead Us? A Learners' Perspective. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Le, T. (2002). Collaborate to Learn and Learn to Collaborate. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Ledeczi, A., Bapty, T., Karsai, G. and Sztipanovits, J. (1995). Modeling Paradigm for Parallel Signal Processing. Australian Computer Journal 27(3): 92-102.

This paper introduces a model-based environment and its application in the parallel signal processing domain. The key concepts of the approach are the domain-specific model-based programming environment and the automatic software synthesis technique enabling non-software engineers to build complex applications. Graphical model building, multiple aspects, hierarchy, and multiple views help manage the complexity of the application. The configurable model builder and the unified run-time support make the use of the same core technology in different domains possible. In the parallel signal processing domain, the signal flow graph, the hardware topology and resources, and the assignment constraints are modelled. A macro dataflow graph is generated from the signal flow model, then partitioned and mapped onto the processor network satisfying the assignment constraints. The required makefiles, message routing maps, and network loader configuration files are also automatically generated. Different system engineering tools provide hardware topology verification and performance prediction based on information extracted from the models.

Lederer, B. R., Dakin, R. J., Parker, K. R. and Cook, A. L. V. (1988). CSIRONET's Terabit File Store. Australian Computer Journal 20(1): 33-40.

The terabit File Store is a large scale storage facility based on a Braegen Automated Tape Library and disc cache. The software controlling the facility is designed to support backup and archiving of files by users operating in an environment including communicating multi-vendor mainframe hosts on a local area network. Hosts currently serviced include a Fujitsu M180 computer, on which the control program runs, two Control Data Corporation Cyber 800 series computers, and a Fujitsu M380 computer. All hosts communicate via Control Data Corporation's Loosely Coupled Network. Incoming small files up to 30M bytes in size are buffered to tape via the disc cache; large files up to 1.2G bytes are transferred directly to tape. A special purpose catalogue records file locations on disc or tape and provides user facilities for managing large holdings of files including heirarchical subdirectories, subdirectory comments, multiple instances of the same named file distinguished by time and date of creation, keep limits to control the number of instances of a file retained, retention periods, user group control over storage allocation, and sharing of files between users and hosts.

Lee, J. Y. and Zic, J. (2002). On Modelling Real-Time Mobile Processes. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Lee, W. J., Cha, S. D., Kwon, Y. R. and Kim, H. N. (2000). A Slicing-Based Approach to Enhance Petri Net Reachability Analysis. Journal of Research and Practice in Information Technology 32(2): 131-143. First Page.

Reachability graph analysis is one of the most widely used techniques to verify the behavior of asynchronous and concurrent systems modeled in Petri nets. Unfortunately, state explosion problems is often the bottleneck when applying Petri net modeling and analysis to large and complex industrial systems. This paper proposes an approach in which Petri net slices are computed based on structural concurrency inherent in the P/T net and compositional reachability graph analysis is performed. Petri net slices are proven to provide behavioral equivalence to P/T nets. This approach may enable verification of properties such as boundedness and liveness which may fail on unsliced P/T nets due to state explosion problem. Effectiveness and scalability of our approach is demonstrated using both dining philosophers and feature interaction problems found in telecommunication software.

Lees, M. J. (1971). Small Digital Computers for the Control of Mineral Processing Plants. Australian Computer Journal 3(4): 146-149.

A research group within the Department of Mining and Metallurgical Engineering at the University of Queensland has been investigating techniques for the automatic control of mineral treatment processes. The research project commenced in 1962 and has been supported by grants from Mount Isa Mines Ltd. and the Australian Mineral Industries Research Association. A Digital Equipment Corporation PDP 8/I process control computer has been used for investigations into the automatic control of metallurgical grinding circuits and also for the collection of plant data. In addition, the machine has been used extensively for the assessment of control concepts and for the training of students and plant metallurgists in digital control techniques.

Leitch, S. and Warren, M. (2001). The Issue of Ethics in Electronic Commerce. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Ethics is an important element in all aspects of computing, but proves to be a real problem in the development and delivery of electronic commerce systems. There are many aspects of ethics that can affect electronic commerce systems, but perhaps the most notable and worrying to both consumers and developers is that of trust. In a world where so much information is transmitted and shared electronically, ethical standards that in general society are applied to this medium, are often ignored or forgotten. This paper will discuss some of the ethical considerations that should be considered in electronic commerce and offer the possible solutions that can encourage developers to consider ethical considerations and prove excellence and trust to the consumer.

Lemke, R. L. (1972). A Modem for Miller Coded Digital Data. Australian Computer Journal 4(1): 16-20.

A new modem for Miller coded serial data has been designed for both the telecommunication and the magnetic tape storage of serial data. Features of the Miller code, such as narrow band-width requirements and tolerance to phase distortion, are described along with characteristics of some of the better known coding techniques. The new modem design provides improved clock regeneration circuitry to compensate for the Miller code's dependence upon a one-zero-one sequence for initial synchronization. The modem design is described with logic diagrams and an evaluation is given of the design as implemented for a transmission rate of one million bits per second.

Leung, C. M. R. and Nijssen, G. M. (1987). From a NIAM Conceptual Schema into the Optimal SQL Relational Database Schema. Australian Computer Journal 19(2): 69-75.

The design of a correct file structure of an information system requires a thorough understanding of the users' needs. Unfortunately, end-users, usually database design laymen, are often excluded from this step. This paper suggests a solution which allows them to be actively involved in the relational database design stage. We first identify the relationship between the NIAM Conceptual Schema and the Relational Model. Based on these relationships, a well-defined transformation algorithm which transforms a well-formed NIAM conceptual schema into a semantically equivalent SQL relational schema in Optimal Normal Form is described.

Levin, L. S. and MacLeod, I. M. (1996). Understanding Faults: A First Step in Developing Fault-Tolerant Computer Systems. Australian Computer Journal 28(3): 81-87.

The development of fault-tolerant computer systems requires an in depth understanding of the nature and types of faults that can occur. Descriptions of fault-tolerant systems tend to focus on certain attributes of faults that facilitate either detection or recovery in a particular system. As a first step towards developing a more general classification of the effects and causes of faults the nature of faults in computer systems is reviewed and published classifications are analysed.

Levin, P. (1975). The Need for Operator Training. Australian Computer Journal 7(1): 46.

The continued growth of computer installations in commerce, government and industry dictates a need for formal training of computer operators. This article discusses the question of training and those areas which should be included in any worthwhile training programme.

Lewis, T. W. and Powers, D. M. W. (2001). Lip Feature Extraction Using Red Exclusion. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Lewis, T. W. and Powers, D. M. W. (2002). Audio-Visual Speech Recognition Using Red Exclusion and Neural Networks. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Li, F. and Lui, Y. (2001). On Smoothing Algorithms for Transmission of Stored MPEG Video. Journal of Research and Practice in Information Technology 33(3): 194-209. First Page.

In this paper,we consider smoothing algorithms in delivering stored varied-bit-rate (VBR)MPEG video over high-speed network.The required network bandwidth of a video service significantly affects its cost. Video smoothing techniques promise reduced bandwidth variablity and consequently reduced bandwidth requirement. Because of varying frame size,MPEG video introduces burstiness during transmission,when left unalleviated,will affect network management and resource utilisation.Various smoothing algorithms have been proposed to tackle bursty transmissions,giving optimal transmission schedules under various constraints.The first part of the paper gives a survey of the state-of-art smoothing algorithms for stored VBR videos.In the second part of the paper our work on satisfying each video bandwidth request under limited available bandwidth is presented.

Li, W. and Zhang, M. (2001). MAT: a Mobile Agent System for Supporting Autonomous Mobile Agents. Journal of Research and Practice in Information Technology 33(3): 210-226. First Page.

Mobile Agent Template (MAT)is a mobile agent system that is under study and development at the Institute of Computing Technology, Chinese Academy of Sciences and sponsored by the University of Wollongong, Australia. MAT is not an alternative to other mobile agent systems, but is an agent system that can provide the autonomy to mobile agents. MAT tries to support new Web applications, such as the mobile computation, by autonomous and mobile agents.Mobile Thread Programming Model (MTPM), Distributed Task Plan (DTP)and Active State Space (ASS)are integral components on which MAT is constructed.Integration of these three components provides agents with an autonomous work mode and an autonomy- supporting execution environment.In this paper,we define autonomies of agents in the context of mobility and propose our autonomous theories,which are autonomous workflow, asynchronous and localised interactions, and a virtual supporting environment. This paper also outlines current implementation mechanisms of MAT including architecture,program paradigm, distributed task planning and communications. The main contributions of this research are that: (1)workflows are adopted as agents 'working modes;(2)a goal-directed and dynamic task planning is used to deal with the heterogeneity and dynamism of networks; and (3)a virtually platform-independent environment is constructed to provide mobile agents with asynchronous, anonymous and fully localised interactions.The innovation of this research is to provide a new solution for novel Web applications such as mobile computations by using MAT.

Li, Y., Peng, S. and Chu, W. (2002). Metacube - A New Interconnection Network for Large Scale Parallel Systems. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Liao, C.-H. and Shieh, J.-J. (2002). Exploiting Speculative Value Reuse Using Value Prediction. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Lim, Y., Xu, C. and Feng, D. D. (2002). Web-based Image Authentication Using Invisible Fragile Watermark. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Lim, Y. S., Feng, D. D. and Cai, T. W. (2001). A Web-based Collaborative System for Medical Image Analysis and Diagnosis. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Lin, Z., Jin, J. and Talbot, H. (2001). Unseeded Region Growing for 3D Image Segmentation. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Lindsay, P. (2001). Improved Acquisition Processes for Safety-Critical Systems in the Australian Department of Defence. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

This paper describes recently developed policy and procedures for safety management during system acquisition within the Australian government's Defence Materiel Organisation (DMO). The thrust of the safety policy is that: all systems are considered safety-critical until shown otherwise; and any project acquiring or upgrading a system involving safety-critical elements is required to establish a System Safety Program during acquisition, and to deliver a Safety Case prior to acceptance into service. The policy is spelled out in detail, and recommended acquisition procedures are described.

Lindsay, P. and Connelly, S. (2002). Modelling Erroneous Operator Behaviours for an Air-Traffic Control Task. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Lindstrom, B. and Wagenhals, L. W. (2002). Operational Planning using Web-Based Interfaces to a Coloured Petri Net Simulator of Influence Nets. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Lions, J. (1985). The Development of a Correspondence Package. Australian Computer Journal 17(3): 131-135.

The development is described of a software package that manages and supports the correspondence of a journal editor. The package is based on the standard commands of the UNIX Timesharing system with some simple extensions, and has evolved from a straight word-processing system to one that keeps all relevant information on-line. Reasons are given for not pursuing an 'expert program' approach and for not hastening into the use of electronic mail.

Lions, J. (1987). The Australian Computer Journal: Twenty Years On. Australian Computer Journal 19(4): 185-189.

The Australian Computer Journal is twenty years old in November 1987. This article reviews the history and achievements of the journal during its existence.

Lister, A. M. (1982). Software Science - The Emperor's New Clothes? Australian Computer Journal 14(2).

The emergent field of software science has recently received so much publicity that it seems appropriate to pose the question above. This paper attempts to provide an answer by examining the methodology of software science, and by pointing out apparent anomalies in three major areas: the length equation, the notion of potential volume, and the notion of language level. The paper concludes that the emperor is in urgent need of a good tailor.

Little, S. E. and Margetson, D. B. (1989). A Project-Based Approach to Information Systems Design for Undergraduates. Australian Computer Journal 21(3): 130-138.

Popular stereotypes of computing professionals resemble Weizenbaum's (1976) "compulsive programmer" and many technically focussed educational curricula might appear to reinforce this image. However, a broader consensus of the professional tasks comprising software engineering and information systems design is emerging. This paper describes a degree programme aimed at integrating technical skills with their organisational and social context. It emphasises the central role of student project work as an integrative device at each level of a three year undergraduate course drawing upon the first three years of experience with second year projects.

Little, S. E. and Sauer, C. (1990). Social Aspects of Computing in Computing Education. Australian Computer Journal 22(2): 30-35.

Currently the social aspects of computing are readily acknowledged as worthy of at least some consideration. However, the best strategy for their effective incorporation into the education of prospective computer professionals is less uncontroversial. There is resistance to the introduction of additional material to an already full syllabus in which new skills and techniques are constantly fighting for attention. There are also difficulties in communicating to undergraduates material which until recently was simply left to the experimental learning of newcomers to the workforce. Several initiatives are emerging in Australian and overseas institutions, and the advent of an Australian standard on Software Quality Management offers one possible framework for integrating technical organisational and social aspects of computing.

Liu, C. and Jin, J. S. (2002). Modelling and Design of VAML. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Liu, Y., Gorton, I., Liu, A., Jiang, N. and Chen, S. (2002). Designing a Test Suite for Empirically-based Middleware Performance Prediction. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Lloyd, J. W. (1983). An Introduction to Deductive Database Systems. Australian Computer Journal 15(2): 52-57.

This paper gives a tutorial introduction to deductive database systems. Such systems have developed largely from the combined application of the ideas of logic programming and relational databases. The elegant theoretical framework for deductive database systems is provided by first order logic. Logic is used as a uniform language for data, programs, queries, views and integrity constraints. It is stressed that it is possible to build practical and efficient database systems using these ideas.

Lloyd, M. (2002). Reinvention of Childhood in a Networked World. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Lodwick, G. D. and Whittle, J. (1970). A Technique for Automatic Contouring Field Survey Data. Australian Computer Journal 2(3): 104-109.

This paper describes a technique which has been developed to contour field survey data using a digital computer. With irregularly spaced data the method has the advantage that the original observations are contoured rather than the calculated values of a regular grid. Each contour is created in discrete steps with each successive step being positioned by use of calculated values at two points on either side of the projection of the previous step. For each point the value is obtained by fitting a surface to the nearest observations and using the value of the surface at that point. Theoretically, the surfaces considered may be of any degree, though in practice use of weighted planes has been found to combine necessary accuracy with speed. By suitable selection of the number of observations used in the evaluation at a point, contours can be made to agree closely with those drawn by established hand techniques. Use of an overlaying mesh facilitates the commencement and termination of contours. The programs are written in Fortran and are in use on a CDC3200 computer, utilizing a CALCOMP 30-inch off-line plotter. Experience has shown that the production of maps by this technique is efficient and economic in relation to other methods, the principle advantage being in the speed with which quite complex maps can be prepared.

Loh, P. K. K., Hsu, W. J. and Omondi, A. (2002). Embedding of Fault-Tolerant Trees in the Josephus Cube. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Lokan, C. J. (1991). The Design and Applications of Smart Cards. Australian Computer Journal 23(4): 158-164.

Smart cards are the next step after magnetic stripe cards - they are the size and shape of credit cards, but contain a microprocessor and nonvolatile memory. They are useful in many applications, particularly where security is important. This paper outlines the use of smart cards as security devices, their main applications, the principles that influence their design, and their present state of development. The paper concludes with an outline of topics requiring further development.

Lokan, C. J. (1993). The Cleanroom Process for Software Development. Australian Computer Journal 25(4): 129-134.

Recent years have seen increasing interest in better software development processes. One new proposal is the Cleanroom process, which places software development under statistical quality control and produces software with very few defects. This article outlines the Cleanroom process, and describes experience with it to date. The article also describes how elements of Cleanroom might be adopted incrementally.

Louw, G. (1994). Patient Focused Care - Self Contained Units Reduce the Need for Information Processing. Australian Computer Journal 26(3): 99-101.

In the National Health Service (NHS) in the United Kingdom, although computerised information systems are still somewhat undeveloped and untried, the essential belief is that 'the future is in the technology'. There are few instances where perceived need is ever questioned, only the availability of resources to acquire them. In this paper information systems are categorised into two types., 'proceduralised' and 'interpretative' and the need for the latter is challenged. It argues that there is a fundamental critical difference between the two which is, to a large extent, unacknowledged. The types are two ends of a continuum that stretch from from the purely technical, formalised systems bound with structure, measurements and data to those systems that are derived from, and based on, the skills of people in inter-relationships. This paper offers an alternative to interpretative information systems. It suggests that by reducing the need for information processing, the need for information systems is minimised. Information processing can be reduced by developing self-contained units. This paper presents a case study which elaborates on these ideas by looking at the way Patient Focused Care is being developed at the Royal Sussex County Hospital. It shows how a multi-disciplinary group of people are collaboratively designing an integrated, self-regulating unit which ansures effective communication and documentation procedures without using computerised information systems which simply replace computerised information systems, but rather a redesign of work processes. There are shown to be no signifacant inadequacies that interpretative systems could have bettered, yet many of the problems and wastage in resources that tend inevitably to occur when computers are introduced in the NHS are avoided. Additionally, the benefits that are gained by collaboratively designing the various features of their work are enormous.

Low, G. C. and Hunt, D. C. (1988). Multi-Vendor Local Area Networks: Some Technological Issues. Australian Computer Journal 20(3): 138-144.

Technological issues associated with the selection of multi-vendor Local Area Networks are a major concern of MIS managers. As an aid to management gaining an understanding of Local Area Network implementation, the rationale and resulting decisions associated with the design of the Campus Wide Network at the University of New South Wales are discussed.

Low, G. C. and Rasmussen, G. (2000). Partition and Allocation of Objects in Distributed Application Development. Journal of Research and Practice in Information Technology 32(2): 75-106. First Page.

In recent years there has been significant interest in the use of object-oriented techniques for the production of distributed systems. However, only a limited amount of work has been reported on the incorporation of distributed system design issues into object-oriented development methodologies. The identification of processes within a software system (partitioning) and the allocation of these processes to processors in the system is a fundamental problem in the design of distributed systems. Techniques for evaluating the three objectives of task partitioning; minimizing intermodule communications, exploiting concurrency, and limiting the size of processes are presented. The potential concurrency in the object model is graded into three categories. This grading of the potential concurrency between objects/classes is new and is anticipated may assist in the partitioning decision making process. Communication and execution costs required for software allocation are determined from the event diagrams and event traces. The aim of the paper is to use the object-oriented model to produce information that fits into existing non object-oriented decision techniques such as traditional graph theoretic or graph heuristic allocation techniques.

Loy, Z. (1979). Southeast Asia DP Budgets. Australian Computer Journal 11(1): 2-4.

Results of a survey of DP budgets for Southeast Asia are presented. Tables are given for DP budgets for selected industries and DP budgets by installation size. These provide useful information for transfer of technology programs and for comparison of the state of computing.

Lu, X., Rahayu, J. W. and Taniar, D. (2002). ODMG Extension of Composite Objects in OODBMS: A Proposal. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Lucas, R. (2001). Why Bother? Ethical Computers - That's Why!. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

This paper discusses the possibility and implication of ethical computers. A survey of past views is given. Various concepts considered important conceptions of ethics is discussed. The notion of agency and its importance to morality is covered. The consequences of their being ethical computers is examined. A Universal Declaration of Computer Rights is proposed and discussed. Thinking and feeling are not enough to make a computer ethical. Perhaps there are non-human ethics.

Luo, B. and Jesshope, C. (2002). Performance Evaluation on a Micro-threading Pipeline. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Lynch, K., Carbone, A., Arnott, D. and Jamieson, P. (2002). A Studio-Based Approach to Teaching Information Technology. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Macaskill, J. L. C. (1973). Diagonal-Matrix Formulation of Networks for Storage Economies. Australian Computer Journal 5(1): 18-22.

An economical storage method is described for topologically ordered precedence graphs based on use of the diagonal band of the matrix of the graph. Algorithms are given for setting up such matrices and for carrying out typical operations on them for networks of various sizes. Comparisons made with corresponding operations on more conventional graph representations suggests that processing time penalties associated with the use of the matrix diagonal formulation will be unimportant.

Macaulay, M. (1970). Computer Display Devices. Australian Computer Journal 2(4): 136-138.

The purpose of this paper is to give the author's view of the future of computer display devices. This class of equipment has been used with computers from the very beginnings of the industry. The technology of display equipment will undergo little change in the next decade. As computer equipment complexity increases, display equipment except for remote terminals will tend to become less complex. Because of their importance as a communication means between man and computer, the use of display devices will increase and become proportionately greater in future computer systems.

Macdonald, I. D. (1974). An Application of Coset Enumeration. Australian Computer Journal 6(1): 46-48.

The application consists of the construction by machine of a group G of exponent 8 and order 8192, with the property that every element of order 8 lies in the Frattini subgroup of (G).

Macdonald, S. and Lamberton, D. (1983). Tradition in Transition: Technological Change and Employment In Australian Trading Banks. Australian Computer Journal 15(4): 128-137.

There is currently much concern among banking employees about employment levels in banking, a concern which seems to emanate partly from organisational change thought likely to occur within the industry. This paper explores the essential connection between technological change and organisation in banking and concludes that employment levels are dependent on the ability of banks to adapt to technological change, rather than to any direct impact of the technology. Australian trading banks, however, are not accustomed to rapid and radical adaptation; nor would it seem from the results of a large survey of branch employees in Queensland, are bank employees well equipped for the change to electronic banking. The result, particularly in the wake of the Davidson and Campbell Reports and amidst more rapid change in some other sectors of the finance industry and of the economy as a whole, is a high degree of uncertainty that seems to benefit no one.

Machover, C. (1970). CRT Graphic Terminals. Australian Computer Journal 2(3): 117-135.

Cathode Ray Tube Terminals have been associated with digital computers for the past decade or so. Initially, the terminals were used in military command and control systems. "Way back in the mid-fifties, for example, the SAGE system used CRT terminals ( not grossly different from present day units) as one of the primary control devices for our air defence system. However, the use of CRT Graphic Terminals for design purposes in a non-military environment is new. Many digital system historians ... if there be such a speciality ... will date this application of CRT terminals to the pioneering work done by Dr. Sutherland on Sketch-Pad in the early 1960's. My company has been involved in Computer Control Display Systems since 1960 and I must admit that for several of the early years, we felt that we had a cure for which there was, as yet, no known disease. Today, the use of CRT Graphic Terminals in both research and profit-making situations is proliferating rapidly. In fact; one authority estimates that in five years from now - 13 cents out of each computer dollar will be spent on CRT terminals.

Mackenzie, H. and Kelly, G. (1977). A Query/Update Package for Library or Personal Use. Australian Computer Journal 9(4): 155-158.

The implementation of a package to provide access to a data base of bibliographic material is described. The package is written using FORDATA, an implementation of the CODASYL DETG proposals. A high level batch or interactive language is provided, comprising an update component and a set oriented query component, implementation techniques of interest to those implementing similar systems are described, and possible extensions are suggested.

Mackenzie, H. G., Ryan, D. M. and Smith, J. L. (1984). Experiments with a Britton-Lee Database Machine on CSIRONET. Australian Computer Journal 16(2): 63-70.

A small number of special purpose computers for database management are now becoming available. These are being offered as an alternative to mainframe software systems, operating as "back end" machines. One of these, the Britton-Lee Intelligent Database Machine has been integrated into CSIRONET. Some of the experiments and experience gained are described here, and our impressions for the future stated.

Mackenzie, H. G. and Smith, J. L. (1977). The Implementation of a Data base Management System. Australian Computer Journal 9(4): 138-144.

This paper briefly traces the history of FORDATA, an implementation on CDC Cyber computers of the Codasyl Database Task Group's 1971 recommendations. It describes the characteristics and implementation of the various components of the system, and gives reasons for particular design decisions, and suggests possible system extensions.

Macleod, I. D. G. (1970). An Algorithm For In-Situ Permutation. Australian Computer Journal 2(1): 16-19.

In-situ transposition of a vector-stored matrix is an example of the permutation of a set of elements. Any such permutation is composed of a unique set of disjoint cycles, and is most efficiently performed by tracing around cyclic paths and moving elements to their new positions. This paper discusses the problem of choosing the "leader" elements for previously untraced cycles. It is shown that while it is usually not possible to say, without an exhaustive search, that an element has not already been moved, it is comparatively easy to identify, and hence reject as leaders, most of those which have. This reduction in the number of exhaustive searches required, together with the ease of recognising cycles of length 1 and length 2 leads to an effective practical algorithm which is described in detail.

Macleod, I. D. G. (1970). Picture Digitisation via a Modified X-Y Plotter. Australian Computer Journal 2(1): 14-15.

Pictures may be digitised via a modified X-Y plotter which is interfaced to a computer by means of ADC's and DAC's. The picture to be scanned is placed on the bed of the plotter, whose normal pen assembly is replaced by a specially built scanning head. A simple scanner constructed in this manner had a grey-scale resolution of at least 64 levels, a spatial resolution of 0.010in. over an area of 10in. by 15in., and a maximum sampling rate of 200 points per second.

Macleod, I. D. G. (1972). A "Skewed" Data Organisation. Australian Computer Journal 4(3): 143-144.

A method of storing large matrices on fixed-head peripherals such that disparities between row and column transfer times are reduced is described.

Maeng, S. R. and Cho, J. W. (1986). A Control and Data Flow Multiprocessor. Australian Computer Journal 18(1): 26-32.

This paper presents the design of a highly parallel multiprocessor, a control and data flow heterogeneous multiprocessor (CDFM), which combines data flow, parallel forms of control flow, and decoupled access/execute architecture into a hybrid system. CDFM is designed to exploit the potential concurrency at the level of individual operations. A high level program is translated into a set of acyclic directed data flow program graphs and a control program graph in order to exploit the potential concurrency. Each node of the control program graph initiates and controls a data flow program graph. A brief analysis shows that the CDFM architecture and its program organization can exploit concurrency as much as conventional data flow approaches, but reduce greatly the overhead in implementing the loop constructs and array handling operations.

Maheshwari, P. (1997). A Cost Analysis Model for Efficient Dynamic Execution of Parallel Functional Programs. Australian Computer Journal 29(3): 102-110.

It is claimed that financial languages are particularly suitable for programming parallel computers. In this paper, we propose a cost analysis model for parallel functional programs to help the compiler and/or programmer in partitionaing them into larger grain tasks and scheduling them for dynamic parallel execution on a distributed-memory multiprocessor machine. This cost analysis model provides a framework for building a multiprocessor profiling tool for efficient dynamic execution of parallel functional programs. The model can be easily adapted to other parallel declarative languages such as logic programming languages.

Maj, S., Robbins, G., Shaw, D. and Duley, K. (1998). Computer and Network Installation, Maintenance and Management-A Proposed New Curriculum for Undergraduates and Postgraduates. Australian Computer Journal 30(3): 111-119.

Edith Cowan University (ECU) was recently granted level I accreditation of its Computer Science Degree by the Australian Computer Society. Preliminary investigations, however, clearly indicated that, on completion of their studies, graduates could not perform first line maintenance on a Personal Computer (PC) to a professional standard with due regard to safety, both to themselves and the equipment. Nor could they install communication cards, cables and network operating system or manage a population of networked PCs to an acceptable commercial standard. Further, it was noted that the degree provides few options to study health & safety, ethical, legal or human resource management issues that a graduate must address in preparation for a professional career in computer and network management. It appears that this may also he the case with computer science courses at other universities in Australia. Accordingly, this paper presents the case for a portfolio of units in Computer and Network Installation, Maintenance and Management both as an integrated stream within a computer science degree and as an articulated professional award structure to meet this market opportunity.

Maj, S. P. and Veal, D. (2000). Computer Technology Curriculum - A New Paradigm for a New Century. Journal of Research and Practice in Information Technology 32(3/4): 200-214. First Page.

Computer technology is a complex and constantly changing field. These characteristics place considerable on-going demands on teaching and curriculum development. Given the prevalence of PCs this problem is further exacerbated by an increasing number of students from different disciplines attending both introductory and advanced courses on computer and network technology. Lecturers need a new pedagogical framework of a PC based on a new higher-level abstract model. This model must be suitable for a wide-range of students, assist in the development of understanding, support different levels of technical detail and be valid for both current and future generations of digital technologies. This paper proposes bandwidth-nodes as such an abstract model and the basis of computer and network technology curriculum. Work to date indicates that modelling the PC as a collection of nodes, whose performance is rated by bandwidth measured in frames/s, provides a viable constructivist framework that is readily understandable by students from all disciplines. Results to date indicate this framework is also valid at increasing levels of technical complexity. Furthermore, it is essential to provide students with procedural knowledge that is relevant to both student and employer expectations. Competency based testing is proposed as a mechanism to provide assurance of appropriate levels of such practical skills and results of its implementation are presented.

Makela, M. (2002). Efficiently Verifying Safety Properties with Idle Office Computers. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Malcolm, P. J. (1973). A Machine Independent Design for an APL Translator. Australian Computer Journal 5(1): 8-17.

Basic design aspects of the translator are presented and discussed with particular reference to the problem of improving system performance by refining the system and code optimization. The translator functions as two modules, for analysis and execution, run under an operating system provided by the installation. These are designed to give maximum flexibility for development by providing a means of conversion between interpretive and compiler installations, thus enabling effective allocation of coding resources for the pilot implementation. A mapping of the APL symbol set into a limited character symbolism for use on teletype-like input/output devices is also presented.

Malik, M. A. (1982). A Language for Verifiable Modular Programming. Australian Computer Journal 14(4): 137-142.

Using a constructive approach in program design, large programs are developed as a hierachy of program modules. This paper describes a simple language suitable for the design of well-structured program modules. The language presented here was developed as part of a program verification system developed at the Queen's University of Belfast and consequently in design was graetly influenced by the program verification techniques used by that system. The paper does not include annotation relevant to verification or verification stages. The language is based on PASCAL but omits some unstructured and most structured types, user-defined types and global variables. It includes a modified version of SIMULA-67 class as a model data representation feature.

Maloney, W. T. (1981). Transport Australia Packet Switching Network. Australian Computer Journal 13(2): 34-41.

The Commonwealth Department of Transport is currently involved in the development of a modern packet switching network for interchange of aeronautical data. The project has involved considerable hardware and software design, in addition to the usual station design. An overview of the design philosophy is presented and the hardware and software approach to implement the network is described. The important international standards and their application in the national environment is discussed.

Mangan, P. and Sadig, S. (2002). On Building Workflow Models for Flexible Processes. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Mansfield, J. (1985). WORD? - A Paradigm of an Expert. Australian Computer Journal 17(1): 38-41.

The Structure of a particular expert system is described in detail. The system WORD? takes an active part in a word guessing game. The paper discusses the application of this expert system as an aid to the teaching of expert system construction.

Mapelsden, D., Hosking, J. and Grundy, J. (2002). Design Pattern Modelling and Instantiation using DPML. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Mark, D. M. (1986). Construction of Quadtrees and Octtrees from Raster Data: A New Algorithm Based on Run-Encoding. Australian Computer Journal 18(3): 115-120.

This paper presents a new algorithm for constructing linear quadtrees from raster data. The quadtree representation method termed two dimensional run-encoding is used to define a raster dummy image for each individual raster. The raster dummy image has the actual image values (colours) for pixels on the raster, but assigns the value NULL to all pixels outside the current raster. Individual raster dummy images are then combined using a straight-forward Boolean overlay procedure, with all values having priority over NULL. The complexity of this algorithm is linear in both the number of image pixels and in the number of quadtree leaves. The linear behaviour is achieved by preserving the spatial order inherent in the raster image during the execution of the algorithm. The extension of the algorithm to octtrees for three-dimensional data is straightforward.

Marlin, C. D. (1986). Language-Specific Editors for Block-Structured Programming Languages. Australian Computer Journal 18(2): 46-54.

The most common means of creating and manipulating a program is the text editor, which treats a program as a sequence of characters organized into lines. A recent development has been the emergence of language-specific editors, which enable the program to be created and manipulated using commands which take account of its structure. Knowledge about the structure of the program being edited can then be used to provide a more convenient program development tool. This paper examines a particular class of language-specific editors, those for block-structured programming languages. Examples of such editors are described and some issues in their design identified.

Marriott, A., Beard, S., Haddad, H., Pockaj, R., Stallo, J., Huynh, Q. and Tschirren, B. (2000). The Face of the Future. Journal of Research and Practice in Information Technology 32(3/4): 231-245. First Page.

The technological union of ubiquitous personal computers, cheap high-performance graphics and audio, the Web and its expectations, international standards for showing multi-media, and research into Artificial Intelligence and Text to Speech Synthesis systems has recently resulted in Talking Head interfaces to applications and information. This paper details how our initial observations about how people relate to computer generated Talking Heads helped us to create a more believable and realistic Talking Head - a more humane Talking Head. The paper also presents results from the subsequent evaluation of the realism, believability and acceptability of the new Talking Head. Finally we look at where we go to from here and future applications of the Talking Head Technology.

Marshall, S., Biddle, R. and Tempero, E. (2002). How (Not) To Help People Test Drive Code. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Marshall, S., Jackson, K., McGavin, M., Duignan, M., Biddle, R. and Tempero, E. (2001). Visualising Reusable Software Over The Web. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Martin, A. and Chan, M. (1996). Information Systems Project Redefinition in New Zealand: Will We Ever Learn? Australian Computer Journal 28(1): 27-40.

Information Systems project redefinition is an ongoing phenomenon in organisations. This paper reports on a study carried out in June 1994 concerning IS project redefinition in a sample of the larger corporations in New Zealand. The study developed previous research by investigating a greater range of factors, and by actively comparing redefined projects with smoothly completed ones. The paper primarily identifies and discusses significant issues which are associated with project redefinition, but it also reports some IS department and project profile statistics. It suggests that projects which are perceived from their outset as likely to be problematic are not necessarily the ones which eventually turn out to be so. A theme of learning emerges from the findings and discussion.

Martin, K. M., Pieprzyk, J., Safavi-Naini, R. and Wang, H. (1999). Changing Thresholds in the Absence of Secure Channels. Australian Computer Journal 31(2): 34-43.

The ways the threshold parameter can be modified after the setup of a secret sharing scheme is the main theme of this work. The considerations are limited to the case where there are no secure channels. First we motivate the problem and discuss methods of threshold change when the dealer is still active and can use broadcasting to implement the change required. Next we study the case when participants themselves initiate the change of threshold without the dealer's help. A general model for threshold changeable secret sharing is developed and two constructions are given. The first generic construction allows the design of a threshold changeable secret sharing scheme which can be implemented using the Shamir approach. The second construction is geometrical in nature and is optimal in terms of the size of shares. The work is concluded by showing that any threshold scheme can be given some degree of threshold change capability.

Martinez, J. (2002). Database Browsing. Journal of Research and Practice in Information Technology 34(1): 20-33. First Page.

In the field of database browsing, there has been much recent effort leading to advances in hypermedia methodologies. Based on this previous work and the projects that we have implemented on this topic, we provide a formal framework to clarify the concepts and functionality of the various systems. The attributes of the proposal are that: (i) it does not intrude into the database schema, (ii) it has been applied to object-oriented as well as relational databases, (iii) it combines the user - and datacentred approaches, and (iv) it offers a fair trade-off between uniformity and customisability.

Marwood, W. and Clarke, A. P. (1988). A Generic Time-Domain Beamformer Architecture. Australian Computer Journal 20(3): 134-137.

The conventional beamforming equation is decomposed to remove multiplication operations. It is then shown that a beam sample in a particular steer direction can be evaluated by summing a set of traces of matrix products. A low complexity VLSI architecture is described which implements this beamforming algorithm with a linear array of boolean multiply/accumulate elements.

Mason, K. P. and Hood, S. T. (1989). KBESM - A Prolog Blackboard System. Australian Computer Journal 21(3): 100-107.

KBESM is a laboratory prototype of a knowledge-based system designed to assist in the interpretation of signals intercepted from radar emitters, with the aim of identifying the platforms carrying the emitters, and to track the platforms' subsequent motion and changes in emission characteristics. This paper describes the architecture of KBESM (which is based on the blackboard model) and its implementation in Prolog, illustrates the methods used to process intercepted signals, and shows how domain knowledge can be encoded as rules that assist in the interpretation of the signal data.

Masters, P. R. (1968). Evaluating Programmer Performance. Australian Computer Journal 1(3): 124-129.

This paper discusses the factors that influence the cost of writing computer programs for commercial installations. Simple procedures for reporting and controlling performance are described. Suggestions are made for a wide exchange of information between Data Processing Managers in order to build up a body of knowledge on estimating the work content of programming tasks.

Matzko, S., Clarke, P. J., Gibbs, T. H., Malloy, B. A., Power, J. F. and Monahan, R. (2002). Reveal: A Tool to Reverse Engineer Class Diagrams. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Maxwell, P. C., Baker, P. W. and McCrea, P. G. (1976). Incremental Computer Systems. Australian Computer Journal 8(3): 97-102.

This paper discusses the design of special purpose hardware based on incremental methods, where differences only between quantities are transmitted between modules. In particular, the Digital Difference Analyser (DDA) is considered, with reference to the solution of differential equations. After outlining DDA principles, a number of recently developed design refinements are reviewed which overcome scaling, speed, accuracy and interconnection problems. Consideration is also given to hardware implementation, particularly in relation to integration algorithms and various facets of economisation.

May, A. J. (2001). User-Centred Evaluation of Complex IT&T Within an Operational Environment. Journal of Research and Practice in Information Technology 33(1): 83-97. First Page.

The aim of this paper is to provide guidance for the user-centred evaluation of new and complex Information Technology and Telecommunication systems within an industrial operational environment. This paper draws upon practical and methodological experience gained over a period of nearly a decade in order to: (1) Discuss the efficacy or otherwise of some typical Human Factors evaluation techniques, (2) Describe the common constraints that are likely to arise during an industrially-based evaluation process, (3) Provide guidance for overcoming these barriers to a successful and informative evaluation process. Specifically, this paper aims to identify some of the key requirements for under-taking a successful evaluation process within a challenging environment and presents recommendations to maximise the efficacy of the evaluation effort.

Mazanov, A. (1973). A Numerical Method for Solving Population Equations Containing Variable Lags. Australian Computer Journal 5(2): 74-76.

A guano-mite population study leads to the development of a method, for generating numerical solutions of lag-differential equations in which the lags vary. Age structure and quiescence are also handled by this technique. The method is generalised to handle many lags and more than one population with lags.

McCarthy, J. and Thredgold, J. (2002). Modelling Smart Security for Classified Rooms with DOVE. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

McCrae, M. (1985). Office Automation - Towards an Integrated National Approach. Australian Computer Journal 17(3): 136-139.

This communication argues that the subject of office automation (OA) is a more complex and integrated task than portrayed in the literature. The danger of focusing on individual elements in isolation from each other and from other relevant areas is stressed. The paper identifies an urgent need for professional bodies to contribute on two levels. First, by providing guidance on reviewing, defining and agreeing on fundamental terms, key issues and methodologies. Second, by ensuring coordination and liaison between the varied sectional interests in the OA arena. The analysis concludes by offering some suggestions as to basic requirements for coordinated approaches to the subject, especially at the professional body level, where committees are asked to offer recommendations and position papers in the 'state of the art'; and to sponsor and encourage future research efforts. As one of the major professional bodies in the field, the ACS will no doubt be asked to progressively increase its participation in these OA issues.

McCrea, P. G. (1975). An Economical High Speed Display Processor. Australian Computer Journal 7(1): 3-6.

The design of an economical high speed display processor, using a colour TV receiver as an output device, is presented. Fast plotting rates have been obtained by using a MOS random access memory to refresh the display. Special purpose hardware is provided for generating circular arcs as well as vectors and the system is interfaced to a small computer via an asynchronous bus. When graphical facilities are not required, the refresh memory may be accessed as part of normal address space, thereby providing an additional 12K of high speed memory to the CPU.

McCusker, S. (1976). Software Tools for Teaching Computer Organisations. Australian Computer Journal 8(1): 2-6.

The paper describes the use made of software logic simulators in teaching computer organisation at the Canberra College of Advanced Education. A new logic simulator that is being developed is described. This new simulator provides several important facilities that were not provided in the old one.

McDermid, J. A. (2001). Software Safety: Where's the Evidence?. In Proc. Sixth Australian Workshop on Industrial Experience with Safety Critical Systems and Software, Brisbane, Australia, Lindsay, P., Ed. ACS. Full Text.

Standards for safety critical software usually either mandate or recommend development and assessment techniques which are deemed appropriate to reduce the risk of flaws in the software contributing to accidents. These recommendations are usually broken down into a number of "levels" of rigour, with the highest levels being applied where the consequences of failure, or risk, are most severe. The paper discusses the extent to which it is possible to find evidence that there is a genuine variation in risk with level, i.e. that the principles in the standards are sound, and questions some of the assumptions underlying these standards. The paper then goes on to discuss the potential advantages of using product-based evidence to demonstrate safety of software, as opposed to relying on process prescription. It outlines current work on developing and applying "evidence frameworks" as alternatives to the process-based approach, and identifies some of the challenges in gaining widespread acceptance of such approaches. Finally the paper discusses the ALARP principle, and what would be necessary to show that risks associated with safety-critical software have been reduced ALARP. The paper concludes that there are some fundamental difficulties with applying the ALARP principle to software, which neither the process nor evidence-based approaches to demonstrating software safety can readily resolve.

McDonell, K. J. (1976). The Design of Associative Key Lists (Secondary Indices). Australian Computer Journal 8(1): 13-18.

This paper outlines the types of processing environments in which associative key lists may be used to advantage. The two most common organisations of associative key lists are the 'multi-list' structure and the 'inverted index'. These two techniques are described and compared (using largely qualitative assessments), with particular reference to space requirements and the influence (upon performance) of the main file organisation, main file processing (record addition, modification, retrieval and deletion) and the sequence of the entries within the lists.

McDonell, K. J. and Montgomery, A. Y. (1973). The Design of Indexed Sequential Files. Australian Computer Journal 5(3): 115-126.

The paper commences with a tutorial discussion on the IBM Indexed Sequential Access Method (ISAM). A method is then presented which gives a quantitative approach to the design of indexed sequential files. Formulae are presented which use results from a paramatric simulation model to compute the expected file processing time. The broad determining factors on file performance are considered, especially block size, cylinder index placement and overflow usage. Some suggested improvements to the basic indexed sequential organisation are presented.

McGarth, G. M. (1987). The Transition to Fifth Generation Technology: Conceptual Schema Implementation. Australian Computer Journal 19(1): 16-24.

An approach is detailed for transforming a binary-relationship conceptual schema into a semantically equivalent logic representation. The target schema is suitable for direct implementation with logic-based fifth generation technology. A powerful domain independent inference mechanism and an information filter design for information base updates is presented. The information filter design emphasises run-time efficiency, while preserving clarity of integrity constraint specifications in logic update procedures.

McGeorge, J. A. (1968). CARBINE - a Computer Automated Real-time Betting Information Network. Australian Computer Journal 1(3): 143-148.

A general description is given of the performance requirements of the Victorian Totalizator Agency Board's real-time computer system, and of the methods employed in meeting some of these requirements.

McIntyre, G. A. and Ward, M. M. (1968). Estimators of Percentile Points of the F Distribution. Australian Computer Journal 1(2): 113-114.

Approximating expressions for F(DF1,DF2,P) at P=0.25,0.10,0.05,0.01, and 0.001 of the variance ratio distribution are given for DF1 and DF2 over ranges 1,120 and 1,x respectively.

McKay, J. (1998). Using Cognitive Mapping to Achieve Shared Understanding in Information Requirements Determination. Australian Computer Journal 30(4): 139-145.

This paper discusses some of the major issues in information requirements determination, and argues that failure to remedy or attend to these issues may ultimately contribute to failures in information systems development projects. A key to improving the practice of information requirements determination is suggested to be in ensuring that a shared understanding between analyst(s) and key participants. Yet this concept of shared understanding is itself shown to be problematic. An action research study which demonstrated the helpfulness of cognitive mapping in achieving shared understanding is described and discussed.

McKinnon, A. E. and Raymond, E. (2001). Visualising the Probability Distribution Function of Uncertain Data - Application to Stochastic Modelling of Ground Water Solute Transport. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

McLean, M. J. (1978). A Survey of Interactive Graphics Software. Australian Computer Journal 10(1): 11-22.

Interactive graphics software is designed to simplify the task of implementing application programs which use interactive computer graphics. Software systems range from modest sets of subroutines for controlling simple displays to special languages with facilities for controlling asynchronous events from a variety of input devices. The survey is intended primarily for persons who are already familiar with the basic principles of interactive computer graphics but not with the literature. It classifies previously published graphics software systems according to their dominant characteristics and describes the chronological development of the systems within each class.

Melser, P. and Byrne-Armstrong, H. (2001). Corporate Voices, Personal Voices: The Ethics of the Internet. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Two distinct discourses are competing for dominance of the Internet. Each of these "voices" identifies different ethical issues as being the key ones. The Corporate voice of press releases and official company statements makes the legal enforcement of property rights a key issue. Advocates of the "personal voice" of e-mails and chat rooms make freedom of expression and personal conversation more important. The paper compares these contesting ethical visions for the Internet. Neither voice makes a serious issue of "privacy of personal information", a key concern of a more "humanist" intellectual tradition associated with public institutions. The issue is more the relationships and relative strengths of these discourses. "Ethical conversations" are one way in which the personal voice can be strengthened within organisations.

Meyenn, A. (2001). A Proposed Methodology for the Teaching of Information Technology Ethics in Schools. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Middendorf, M., Schmeck, H. and Turner, G. (1995). Sparse Matrix Multiplication on a Reconfigurable Mesh. Australian Computer Journal 27(2): 37-40.

In this paper we show how mesh-connected n x n-processor arrays with dynamically reconfigurable busses can be used efficiently to compute the product of sparse n x n-matrices A and B. If A contains at most 0(1) nonzero elements per row, and B contains at most 0(1) nonzero elements per column, the time of the algorithm is in 0(1).

Mili, F., Alaya, B. and Mili, A. (1988). On the Analysis of Iterative and Recursive Programs. Australian Computer Journal 20(1): 27-32.

Strongest invariant functions have proven useful in analysing some functional aspects of iterative programs. In this paper we investigate their relationship to fixpoints of recursive programs.

Miller, A. J. (1985). DESIGN - A Prototype Expert System for Design Oriented Problem Solving. Australian Computer Journal 17(1): 20-26.

This paper outlines the development of a prototype Expert System for the design of concrete mix specifications. It discusses the design oriented COMIX system which consists of the DESIGN engine coupled to a knowledge base dealing with concrete mix design. The complexity and sequential nature of the design process requires the factoring of the solution into subproblems, each of which is solved as required. The system represents each subproblem as a collection of frames and production rules, which describe to the engine the layout of the knowledge and the feasible solution path which must be followed in order to reach the correct solution. Means are provided for explanation of the systems actions and also for the bulk storage of knowledge as tables and a glossary.

Miller, M. and Seberry, J. (1989). Relative Compromise of Statistical Databases. Australian Computer Journal 21(2): 56-61.

Statistical databases are databases in which only statistical type of queries are allowed. The results of the ststistical queries are intended for statistical use only. However, it has been shown that using only statistical queries it is often possible to infer an individual's value of a protected field (e.g. using various types of trackers). In such a case we say that the database has been (positively) compromised. Various types of compromise have been studied but until now attention has centred on the inference of exact information from permitted queries. In this paper we introduce a new type of compromise the 'relative' compromise: a set of records is relatively compromised with respect to a field X if the relative order of magnitude of the X-value of the set is known. This paper shows that even when exact information is protected, relative information may be accessible. We consider several sets of conditions under which this compromise can occur using SUM type queries of fixed query set size, as well as some of the possible consequences of relative compromise.

Miller, S. (1997). Privacy and the Internet. Australian Computer Journal 29(1): 12-15.

The paper begins with an outline of the general notion of privacy, including the relationship between privacy and individual autonomy. It is argued that the notion that privacy is an absolute right that cannot be overridden under any circumstances is unsustainable, whether it be privacy on the Internet or on any other communication or information system.

Mingins, C. A. and Chan, C. Y. (2002). Building Trust in Third-party Components using Component Wrappers in the .NET Frameworks. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Mitchell, M. (2001). Use of Directed Acyclic Graph Analysis in Generating Instructions for Multiple Users. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Mitchell, M. (2001). Use of Series Parallel Digraph Analysis in Generating Instructions for Multiple Users. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Mitchell, P. E. and Yan, H. (2002). Newspaper Document Analysis Featuring Connected Line Segmentation. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Mitra, S., K. and Banerjee, S. N. (1971). On the Probability Distribution of Round-off Errors Propagated in Tabular Differences. Australian Computer Journal 3(2): 60-68.

The general problem of determining the exact probability distribution of any arbitrarily weighted sum of independent random variables, each distributed rectangularly, has been solved completely. The exact expression for the moments and semi-invariants of the distribution have been obtained. It has been shown that to a first order approximation, the distribution of the weighted sum asymptotically approaches a Gaussian distribution, but is always platykurtic irrespective of the weights. On the customary assumption that the round-off errors are independent random variables distributed uniformly between +- 1/2 units of the least significant digit, the problem of propagation of round-off errors in tabular differences has been studied in detail. The computed values of the probabilities have been compared with the earlier results obtained empirically by Comrie, and theoretically by Lowan and Laderman, van Wijngaarden and Sheen, and by Miller.

Moffat, A. and Petersson, O. (1992). An Overview of Adaptive Sorting. Australian Computer Journal 24(2): 70-77.

An algorithm is adaptive if 'easy' problem instances are solved faster than 'hard' instances. Here we give a tutorial overview of the field of adaptive sorting, considering in turn each of the three paradigms for the design of sorting algorithms. We show that each of these paradigms leads to a corresponding family of adaptive algorithms.

Moffat, A. and Zobel, J. (1994). Compression and Fast Indexing for Multi-Gigabyte Text Databases. Australian Computer Journal 26(1): 1-9.

In the last two years we have developed improved techniques for indexing and retrieval of text data, including algorithms for inversion, for compression of the data and index, and for efficient ranking. These techniques were, however,tested on relatively small databases. In this paper we describe the application of these techniques to a large (2 Gb) heterogeneous text database. Our experiments show that compression performance does not degrade with the increase in volume of data, and that response times remain small, confirming that the new techniques are suitable for large quantities of data.

Monostori, K. a., Zaslavsky, A. and Schmidt, H. (2002). Suffix Vector: Space- and Time-Efficient Alternative to Suffix Trees. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Montgomery, A. Y. (1970). Some Aspects of Data Processing Management in Australia. Australian Computer Journal 2(2): 71-78.

The purpose of this paper is to identify and to discuss the major problems currently being faced by Data Processing Managers in Australia and where possible, to offer solutions. Problem identification proceeds by drawing on the author's experience in data processing installations in the U.K., U.S.A. and Australia and by review of articles published in Australian professional data processing journals and bulletins. It is concluded that the most pressing problems stem from the location of the data processing department within the organisation structure, from difficulties in developing quantitative evaluations of costs and benefits for proposed systems, from an inability to set realistic staff performance goals and from rapid technological change. The solutions offered are derived from the application of general management principles and from an evaluation of techniques being used to solve similar problems overseas. The hope is that this paper will present the problems and peculiarities of data processing management to other managers in a form familiar to them, whilst at the same time urging data processing managers to look outside their own field for solutions to their most pressing difficulties.

Montgomery, A. Y. (1974). Algorithms and Performance Evaluation of a New Type of Random Access File Organisation. Australian Computer Journal 6(1): 3-11.

This paper describes the spatial organisation and presents the detailed processing algorithms for a new space-saving form of random access file having two overflow pointers per bucket instead of the more conventional single overflow pointer per record. Simulation studies of the performance of this organisation show that there is little to choose between the new and the conventional arrangements. Using the results of the simulation studies to design random access files shows that a bucket size small compared with a track minimises total processing time even if the proportion of addition and deletion transactions is high relative to the number of retrieval and update transactions.

Montgomery, A. Y. (1974). A Discussion on a Multi-Master Sequentially Organized File Maintenance System. Australian Computer Journal 6(3): 129-140.

Little information appears in the literature about how the design of a multi-master file maintenance system should be approached although such designs are probably commonplace in practice. This paper discusses the problem by outlining a number of questions that arise in the design of such systems and by suggesting alternate answers to these questions. The intent of the paper is tutorial rather than expository.

Montgomery, A. Y. (1979). An Optimising, Transportable, Restartable Sort Merge Package - A Case Study. Australian Computer Journal 11(4): 133-141.

This paper discusses a number of factors found important during the design and building of a disc sort/merge package with restart capability initially implemented in FORTRAN IV on the HP2100A but intended to be subsequently transportable. The major aspects discussed are the choice of tag or record sorting for a given number of records of a given size, the choice of the internal (merge) bucket size, the restartability and the transportability. Readers are made aware of the importance of the tag/record based sorting choice and of the choice of merge bucket size since these two factors significantly affect performance. Reference is made to a report which details a sort time estimation procedure which accurately selects the minimum sort time conditions for a given set of data using this package.

Montgomery, A. Y. (1980). Editorial A Short Essay on Some Problems with Teaching of Computing in Australian Government Institutions Today. Australian Computer Journal 12(2): 46-47.

Montgomery, A. Y. (1987). The Australian Computer Journal: A Twentieth Anniversary Editorial. Australian Computer Journal 19(4): 190-195.

Twenty Deadly Sins Against Professionalism and Progress in Australian Computing.

Moody, D. L. and Shanks, G. (1998). Improving the Quality of Entity Relationship Models: An Action Research Programme. Australian Computer Journal 30(4): 129-138.

This paper is an extension of previous research which developed a framework for evaluating and improving the quality of Entity Relationship models. The framework has now been used extensively in practice, including implementation in two of the largest commercial organisations in Australia. The experiences gained have been used to further develop and refine the framework. This paper describes how the framework has been used in an action research programme to quality assure individual data models as part of application development projects (product quality) and to re-engineer application development procedures to build quality into the data modelling process (process quality). The results show that use of the framework has the potential to significantly improve the practice of data modelling.

Moody, D. L. and Shanks, G. G. (1998). What Makes a Good Data Model? A Framework for Evaluating and Improving the Quality of Entity Relationship Models. Australian Computer Journal 30(3): 97-110.

The choice of an appropriate representation of data is one of the most crucial tasks in the entire systems development process. However in practice, there are few generally accepted guidelines for evaluating alternative models, and little agreement even among experts as to what makes a "good" data model. In the absence of agreed criteria, the choice of an appropriate representation is usually made in an ad hoc way, based on common sense and experience. As a result, data modelling has more of the characteristics of an art than an engineering discipline, and the quality of models produced is almost entirely dependent on the competence of the designer. This paper develops a framework for evaluating the quality of data models and choosing between alternative representations of requirements. The framework has been developed in practice, and has been applied successfully in a wide range of organisational contexts.

Moon, B. A. M. (1971). List-Processing in Plain Fortran. Australian Computer Journal 3(3): 117-125.

By using an algorithmic language to express the procedures of list-processing, the student may receive a practical introduction to its concepts without the need to learn a new language or set of statements. An examination of some possibilities of Fortran for this purpose shows that it is adequate for the presentation of many list-processing concepts and also offers a degree of flexibility in the construction of list structures which some list-processing languages themselves do not permit. Acquaintance with the basic ideas of list-processing is assumed in this paper.

Moore, I. (1979). The Revolution of Microprocessors and Microcomputers. Australian Computer Journal 11(3): 112.

A two day professional development seminar on microprocessors was recently conducted by Queensland A.C.S. Branch. Sessions included keynote addresses, microprocessors in computer configurations, design aids in microprocessor systems, local research projects, microprocessors for applications, applications in local industry, the future - a panel discussion, and microcomputer systems for commercial and industrial development.

Moretti, G. S. and Lyons, P. J. (1986). An Overview of GED, A Language-Independent Syntax-Directed Editor. Australian Computer Journal 18(2): 61-66.

This paper describes GED, a full-screen syntax-directed editor for any LL(l) language that can be defined in Extended BNF (Backus Naur Form). The editor reads the syntax of the target language (in EBNF) augmented with print formatting commands. It displays a pretty-printed outline of the program, automatically inserting all required keywords and symbols. User input is checked on entry, making it impossible to generate syntactically incorrect programs. A 'help' area continuously displays the current productions) and lists allowable start symbols. This display, a multi-level 'undo' command and the program outline generated by the editor provide a Wa@r of exploring the constructs of a language.

Morris, E. J. S. (1999). A Cyberspace Ethics Methodology. Australian Computer Journal 31(3): 83-88.

The conventional method to decide a cyberspace ethical issue transplants the cyberspace scenerio into an analogous situation in our physical world ('realspace'). The interpretation of the realspace issue is intended to clarify the cyberspace issue. However, it is often simplistic because contrasts between cyberspace and realspace are omitted. Observing cyberspace as a phenomenon, the most important property that distinguishes it from realspace is its detachment from the space-time reference system. We demonstrate that five important contrasts exist. We propose a cyberspace ethics methodology (Parallel spaces) that explicitly considers cyberspace and realspace contrasts during analogical thinking. The effectiveness of our methodology is demonstrated in the virtual rape issue. Finally, ethical implications of cyberspace properties are discussed.

Morris, J., Lam, P., Lee, G., Parker, K. and Bundell, G. A. (2002). Determining Component Reliability Using a Testing Index. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Morris, J. L. and Parkinson, M. (1970). Vocational Interests of Computer Programmers. Australian Computer Journal 2(3): 139-142.

The inventoried vocational interests of fifty computer programmers were investigated. The Geist Picture Interest Inventory was used and "strength of interest" scores were expressed in two forms. One scoring system gave the rank order over eleven vocational categories based on means of individuals' scores. Individuals' scores in each category were derived by taking the proportion of expressed first preferences to the total number of items offered for choice within each category. The second method used a normative sample against which raw scores within each category were compared. Both systems were consistent in identifying computational and literary interests as dominant. Scientific interest is strong when the rank order method was used but not when individuals' scores were related to the normative sample.

Morrison, M. and Attikiouzel, Y. (1994). An Introduction to the Segmentation of Magnetic Resonance Medical Images. Australian Computer Journal 26(3): 90-98.

Magnetic resonance imaging is a powerful tool available to radiologists for non-invasively viewing the status of internal tisses of patients. With the huge advances being made in computer processing capabilities, it may be surprising to discover that the enormous quantities of digital data generated by this process are still printed onto plastic film and processed manually by trained specialists. One of the primary reasons for this can be attributed to the inability of computers to automatically extract information regarding the contents of images. That is, carry out what is known as image segmentation. This paper surveys current approaches to the segmentation of magnetic resonance medical images, provides some insight into the problems which are making this a difficult task, and suggests where the future of such research is heading.

Morrison, P. R. and Forester, T. (1990). Teaching Computer Ethics and the Social Context of Computing. Australian Computer Journal 22(2): 36-42.

This paper describes some of our experiences in teaching courses in the social context of computing and outlines a course in computer ethics that is designed to meet the needs of computer science and information systems students.

Murnane, J. S. and Warner, J. W. (2002). An Empirical Study of Junior Secondary Students' Expression of Algorithms in Natural Language. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Murry, C. R. (1974). A Review of Computer Applications in Raw Sugar Manufacture. Australian Computer Journal 6(1): 38-45.

The paper reviews applications of computers in the raw sugar manufacturing industry in Australia. An historical outline of important events from 1960 to 1972 is given and extended to expected developments in 1973. Various applications are then outlined in more detail with references to published material where further information can be found. Mathematical models of the crushing process (both average and dynamic process models) on-line cane receiving applications, computer application in cane transport studies, a model of vacuum crystallisation with on-line control studies, and other current applications are reviewed. Projects to develop a process model for a complete raw sugar factory and to computer control a slave locomotive in a cane train is also outlined.

Nagappan, R. (2001). A Graph Based Model for Navigating Visualisation. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Nagra, J., Thomborson, C. and Collberg, C. (2002). A Functional Taxonomy for Software Watermarking. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Nascimento, H. A. D. d. and Eades, P. (2001). A System for Graph Clustering Based on User Hints. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Nascimento, H. d. (2001). A Framework for Human-Computer Interaction in Directed Graph Drawing. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Natsev, A. P., Fuh, G. Y. C., Chen, W., Chiu, C. and Vitter, J. S. (2002). Aggregate Predicate Support in DBMS. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Nesbitt, K. V. (2001). Modelling the Multi-Sensory Design Space. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Nessett, D. M. (1975). The Effectiveness of Cache Memories in a Multiprocessor Environment. Australian Computer Journal 7(1): 33-38.

One problem associated with multiprocessor systems is how to structure the system so that memory access conflicts are minimized. The use of cache memory has been suggested as one method of overcoming this difficulty. In this study a simulation approach is used to investigate the effectiveness of the above scheme and the results suggest that the employment of cache memories is in many cases desirable.

Newman, B. B. and Hildebrandt, J. (1987). Blind Image Restoration. Australian Computer Journal 19(3): 126-133.

Blind image restoration is concerned with the task of restoring images blurred by an unknown point spread function. The paper begins by pointing out some of the theoretical as well as computational difficulties involved. It then illustrates a deconvolution technique that has been used successfully to restore pre-1920 sound recordings. If the point spread function is known to be symmetric, then the phase of the original image is known which is often sufficient to restore the original image. Finally a new technique of maximum entropy blind restoration is described that can be used to produce an iterative restoration algorithm.

Newmarch, J. D. (1986). A Prolog Environment system. Australian Computer Journal 18(2): 87-89.

A single user system has been implemented to manage the task of writing Prolog clauses and programs. By storing definitions individually and using knowledge about Prolog, an environment is created which reduces errors and code duplications.

Ng, C. S. and Sacks-Davis, R. (1986). A Query Interface for IMAGE Databases Based on Relational Algebra. Australian Computer Journal 18(1): 1-8.

IMAGE is a widely used database management system developed by Hewlett Packard for their HP-3000 series of computers. A query language for IMAGE databases based on relational algebra is proposed. The support provided by the IMAGE architecture for such a language is described. The issues involved in providing a full relational interface are discussed and the limitations of this approach are described. The new query language is compared to existing IMAGE query facilities.

Nichol, D. G., Fiebig, M. J., Whatmough, R. J. and Whitebread, P. J. (1987). Some Image Processing Aspects of a Military Geographic Information System. Australian Computer Journal 19(3): 154-160.

A Military Geographic Information System (MGIS) is a collection of datasets describing spatial characteristics of a region such as terrain elevation, soil type, vegetation type, tree spacing canopy closure etc. Such datasets are very expensive to produce by 'ground truthing' and it would be much more cost-effective if such ground truthing could be done by the analysis of satellite imagery. In addition, most MGIS datasets are stored as two dimensional raster files and their analysis is thus amenable to various image processing techniques. This paper examines processing techniques which are applicable to the assembly and analysis of spatial datasets. These include the use of covariance techniques on satellite multi-spectral images and the efficient use of quadtrees and region adjacency techniques for spatial information extraction. An example of the use of such data, the simulation of radar and visible sensor views, is given.

Nielson, S. (1999). Talking About Change: An Analysis of Participative Discourse Amongst IT Operations Personnel. Australian Computer Journal 31(4): 102-109.

This paper presents some findings from a longitundinal study of the discourse of Operations personnel in a universtiy Information Technology Centre (ITC). The study uses a four dimensional concept of discourse and the wider organisational context. The use of language characteristics of participatory design has been indentified in this study as metaphorical and appropriated by a drive towards increased management control. This paper suggests that in order to understand the nature of change management in an IT organisation, the relationship between discourse and other organisational practices needs to be elucidated.

Noble, J. and Biddle, R. (2001). Visualising 1,051 Visual Programs Module Choice and Layout in the Nord Modular Patch Language. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Noble, J. and Biddle, R. (2002). Program Visualisation for Visual Programs. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Noble, J., Biddle, R. and Tempero, E. (2002). Metaphor and Metonymy in Object-Oriented Design Patterns. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Noble, J., Groves, L. and Biddle, R. (1995). Object Oriented Program Visualisation in Tarraingim. Australian Computer Journal 27(4): 138-149.

Most program visualisation systems display either language level details of programs, or high level details of programs, or high level overviews of the program's algorithm. Producing high level views requires that the abstractions in the program to be visualised (the target program) are described to the visualisation system - either by modifying the target program, or by providing the visualisation system with information about the details of the abstractions in the target program. Object Orientation can be used to organise the design of both the target program and the archictecture of an abstract program visualisation system. Such a system can produce flexible displays of the target program at multiple levels of abstraction, without any extra detailed information about the implementation of abstractions in the target program.

Norcott, A. (1991). A Production Systems Development - Methods and Results. Australian Computer Journal 23(3): 95-104.

This paper indicates the methods used for developing a computer-aided steelworks production system, at the Newcastle, New south Wales plant of the BHP. Throughout the paper an attempt is made to strike a balance between the technicalities and practicalities of developing a production management information system. The first sections are devoted to giving the reader some background information on the plant configurations, computer facilities and approaches used to identify and prioritise information system requirements. Later sections outline the computer system development projects needed to satisfy production information requirements, and indicate, in chronological sequence, systems development steps. The final section lists some pertinent observations on developments to date.

Northcote, R. S. (1973). Syntax Analysis Using FPL. Australian Computer Journal 5(2): 50-56.

After introducing some basic terminology, this tutorial paper describes Floyd Production Language (FPL) as a method for specifying the syntax of a programming language, and then uses both extended BNF and FPL to specify the syntax of FPL itself. The description of FPL leads to the development of an instruction set which may be used to define the action of FPL statements, and the description of a syntax analyser which is an interpreter driven by an FPL syntax table. The latter is obtained from an FPL syntax specification by direct translation.

Northcote, R. S. (1977). A More Effective ACS? Australian Computer Journal 9(1): 4-6.

A message from the President of the Australian Computer Society to members on the occasion of the 10th Anniversary

O'Brien, F. (1980). The Software Compatible Machine. Australian Computer Journal 12(3): 100-104.

The high level of investment in applications programs and proprietary software written for IBM 360/370 architecture systems has given rise to two forms of system, the Plug Compatible Machine, PCM, and the Software Compatible Machine, SCM. This paper considers the technical problems involved in designing and implementing SCM systems, and their inherent advantages over the PCM approach.

O'Callaghan, J. F. (1971). Graphical Communication in Interactive Computer Graphics. Australian Computer Journal 3(1): 12-19.

Interactive computer graphics systems have not fulfilled the promise that many promoters of the graphics terminal had anticipated early in the 1960's. A significant problem has been encountered in attempting to provide natural and efficient communication between men and machine. This aspect is examined by evaluating the state of graphical communication within some developed systems. The conclusion is that a considerable gulf exists between the facilities currently available and those desirable. Research is essential in areas now under study in Artificial Intelligence, for the development of more effective communication and hence more effective graphics systems.

O'Callaghan, J. F. (1976). A Method for Representing Point Data by Regions. Australian Computer Journal 8(1): 7-12.

A method is described for representing labelled points by a set of regions. The points are placed in an array, and are expanded into empty array cells by digital picture operations. The amount of expansion is limited by the sizes of neighbourhoods computed for each point. The neighbourhoods are dependent on the local density of points and are controlled by user-supplied parameters. An explicit clustering algorithm based on the symmetry of neighbourhood relations is incorporated. Uses for the method include producing a clearer visual impression of point data and providing quantitative descriptions of the data in terms of associated regions.

O'Connell, B. M. (1997). Law, Ethics and the Internet: Finding Solid Ground in Virtual Spaces. Australian Computer Journal 29(1): 6-11.

In order to construct a coherent legal and ethical approach to issues confronting the Internet, it is necessary to move beyond its technological nature and investigate the human dynamics which animate its development and popularity. This paper suggests that consideration of the Internet as a community will reflect its true dynamics and produce comprehensive, coherent and accepted resolutions.

O'Connor, A. D. (1992). Soft Systems Methodology - A Case Study of its use Within an Australian Organisation. Australian Computer Journal 24(4): 130-138.

Soft systems methodology (SSM) is a user-driven analysis technique appropriate for application in unstructured (ie soft) problem areas. The following paper specifically discusses the use of SSM within an Australian Organisation. It considers the original application of the approach as a formal planning methodology and the current application of the soft system techniques as informal planning tools. The way in which SSM is currently applied is a direct result of its failure as a formal planning approach. This failure was not the result of problems inherent in the methodology but the result of both the abandonment of the central planning function and the inability of SSM to live up to the company's (particularly the Information Systems planning teams) expectations - expectations which were, in fact, contrary to the underlying philosophy of the approach.

O'Connor, K. (1994). Confidentiality, Privacy and Security Concerns in the Modern Healthcare Environment. Australian Computer Journal 26(3): 70-77.

This paper is based on a speech to the IIR Information Technology and Health Conference, Sydney, 14-15 March 1994.

O'Kane, M. (1985). Capturing Real-Time Uncodified Expertise. Australian Computer Journal 17(1): 2-6.

Real-time uncodified expertise' refers to expertise which is typically exercised in finding solutions to problems requiring an urgent response to a complex situation but which is largely uncodified. In this paper the knowledge engineering and broad system architecture problems associated with the capture of uncodified expertise will be discussed with reference to a study done as preliminary work for the building of an expert system for the Australian Coastal Surveillance Centre.

O'Neill, J. L. (1987). Plausible Reasoning. Australian Computer Journal 19(1): 2-15.

A brief introduction to rule-based expert systems is followed by a review of the best-known approaches to reasoning with uncertainty, including subjective Baysian reasoning, as typified by PROSPECTOR, measures of belief and disbelief, represented by MYCIN and its derivatives, and probability bounding methods, including the Dempster-Shafer theory of evidence and INFERNO. A small example is used to illustrate each inference method.

Oliver, I. (1968). Tree-Searching School Timetables. Australian Computer Journal 1(3): 153-157.

The application of a backtrack, exhaustive search technique to the construction of school timetables is described. An ALGOL procedure is presented as an appendix and the results of some test runs are quoted. The search technique will find a solution, if one exists, very quickly in most cases. Occasionally, however, a problem is encountered which requires a much larger amount of time. The time taken in the worst case tested is still regarded as reasonable compared with other methods.

Ooi, B. C. and Tan, K. L. (2002). B-trees: Bearing Fruits of All Kinds. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Oon, Y. K. and Carson, N. E. (1985). The PORTA Language - A Portable Medical Record System. Australian Computer Journal 17(2): 88-90.

The representation of medical patient data for information interchange is discussed, and a system in current use is described.

Oon, Y. K. and Carson, N. E. (1985). A Rule-Based Expert Drug Interaction Report System. Australian Computer Journal 17(1): 12-13.

Increasing use of prescribed drugs by medical patients implies increasing rates of adverse drug interactions. Reductions in the incidence of such interactions may be achieved with computer technology. A drug interaction report system based on production rules is described. It is designed to function alone or integrated with the patients medical record system.

Osborne, M. R. (1969). A Note on Powell's Method For Calculating Orthogonal Vectors. Australian Computer Journal 1(4): 216-218.

In this note a derivation of Powell's method for calculating orthogonal vectors is given together with a discussion of its stability. An application is to the Rosenbrock algorithm for unconstrained optimisation.

Osborne, M. R. (1972). A Class of Methods for Minimising a Sum of Squares. Australian Computer Journal 4(4): 164-169.

A class of methods for minimising a sum of squares is studied. This class includes Newton's method for systems of n equations in n unknowns, the methods of Gauss and Marquardt for overdetermined systems, and also methods for underspecified systems. In addition it includes modifications to these algorithms in which the correction to the current estimate of the solution is used as a search direction for reducing the sum of squares, and the convergence results, presented relate to the more general situation. Estimates of rate of convergence are also given.

Osborne, M. R. (1976). On the Computation of Stepwise Regressions. Australian Computer Journal 8(2): 61-68.

The basic form of an algorithm for stepwise regression is presented, and consideration is given to its implementation using (a) Jordan elimination applied to the normal matrix, and (b) orthogonal factorization applied to the data matrix. It is known that this second procedure is numerically superior in the standard linear least squares problem so that it is of interest to consider adapting it to the stepwise situation. The details are worked out here, including an error analysis of a non-standard back substitution procedure, and it turns out that the resulting procedure compares favourably in terms of work done with the standard algorithm based on Jordan elimination. A FORTRAN program implementing the orthogonal factorization algorithm is also presented.

Overheu, D. L. (1967). On Intelligence, Intelligent Automata and Robots. Australian Computer Journal 1(1): 28-36.

It is postulated that the essence of 'intelligence' is the ability to select hypotheses about an environment which give a high probability for predicting future events within the environment. Deductive and inductive reasoning are then seen only as tools in the application of intelligence and not specifically as evidence of intelligence. On this basis, it is possible to postulate the existence of active finite state probabilistic automata as intelligent mechanisms inter-acting with their environment. For historical reasons it is proposed that these machines should be called robots. The discussion is intended to be informal but definitive, and is aimed at encouraging the use of the term 'robot' for a particular class of intelligent machines before its misuse relegates it to describing certain automata which perform physical activities.

Overheu, D. L. (1980). Computer Applications in the Totalizator Industry in Australia. Australian Computer Journal 12(3): 93-99.

A review of the development of the use of computers for of-course totalizator betting systems provides a case study of trends in the industry and some of the reasons for these trends. The review runs from 1964 to 1980 and shows a growing development towards the use of distributive processing. It is conjectured that this trend will continue out to the terminal level in some cases with the development of microcomputers. Some mention is also made of software trends towards greater use of higher level languages for these real time online systems. The importance of the industry to computing in Anstralia can be gauged from a turnover in excess of $2,000,000,000 per annum in off-course betting.

Palmer, J. A. B. (1970). An Economical Method of Plotting Contours. Australian Computer Journal 2(1): 27-31.

A method is described for generating a contour map from a surface specified in a rectangular array of heights. The operation is defined as a transformation of the data, and the basic approach to the problem, that of aiming for computational speed with economy of peripheral output, is outlined. The relation of a contour line to the array of heights is defined. The construction of an intermediate data structure defining the map, and its use for fast searching, are described. Details are given of the tables and indexing system, and it is shown how they are used for line generation. Finally an example is shown of the method in use.

Park, H. J., Lee, D., Lee, K. and Chon, K. (1991). Configuration Management of Object Groups. Australian Computer Journal 23(4): 148-157.

Object groups provide a basis for replication and parallelism which increase the opportunities to improve performance, availability or fault tolerance. The improved performance is gained via parallel execution of multiple processes, possibly residing on different hosts. Improved availability and fault tolerance may be gained by replicating a program module in different locations. Conferencing is an example showing a cooperation of multiple objects. However, multiple members in the object group and coordination between them add a major degree of complexity; a large number of objects are involved and the membership continuously changes. The configuration management provides automated support for the object group to selectively hide this complexity. Multiple objects are configured into an object group and behave towards other objects as if the multiple objects were collectively one object. Infrastructure and primitives to support dynamic configuration of object groups are introduced in this paper. The design and principles laid down in this paper are based on the ANSA and SE-ODP which develop open distributed processing models.

Park, M., Wilson, L. S. and Jin, J. (2001). Automatic Extraction of Lung Boundaries by a Knowledge-Based Method. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Parker, B. (2002). Three-dimensional Medical Image Segmentation Using a Graph-Theoretic Energy-Minimisation Approach. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Parkin, I. (2001). Screw Based Computer Graphics. Journal of Research and Practice in Information Technology 33(4): 315-320.

Parkin, I. A. (1978). On Determining the Prime Implicants of a Boolean Function Without Recourse to its Minterm Form. Australian Computer Journal 10(4).

A justification is given of a modification to a method for identifying the prime implicants of a Boolean expression without recourse to its minterm form. The method avoids certain redundancies of earlier methods and, in consequence, offers improved efficiencies in time and space utilisation.

Parkin, N. (1982). The Input Space Model for Software Testing. Australian Computer Journal 14(2): 62-65.

The input space model of software as propounded by Cho is reviewed. The limitations and potential of the model are investigated. The work of Cho is extended to testing of languages defined using Backus-Naurform (BNF). An example of a symbolic input attribute decomposition (SIAD) tree for a PASCAL subset is included to illustrate the method of extension.

Pattison, T. and Phillips, M. (2001). View Coordination Architecture for Information Visualisation. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Pattison, T., Vernik, R., Goodburn, D. and Phillips, M. (2001). Rapid Assembly and Deployment of Domain Visualisation Solutions. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Pattison, T., Vernik, R. and Phillips, M. (2001). Information Visualisation using Composable Layouts and Visual Sets. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Payne, A. (1975). Computer-based Land Transfer and Registration. Australian Computer Journal 7(3): 99-104.

The present procedures of transfer of title to land are based on a system devised over 100 years ago. This paper proposes an alternative computer-based scheme. The advantages of such a scheme are described and an assessment is made of system requirements. Particular attention is given to the organization of files on a land data base.

Payne, A. D. (1973). Program Execution and F-Algebras. Australian Computer Journal 5(2): 70-73.

An algebraic approach to programs and machines is presented. The analysis is based on the theory of F-algebras which are defined and developed in appropriate directions. Program execution is described in terms of an algebraic model which is closely associated with the action of digital machines.

Payne, A. D. (1977). Error Control for Computer Communication. Australian Computer Journal 9(2): 80-87.

A basic problem of communication system design is the optimisation of block length for effective use of the channel capacity. In this paper a simple but realistic error model is proposed to facilitate practical solutions for some well-known error control methods. Results are presented in graphical form.

Payne, A. D. and Lings, B. J. (1978). Topological Design of a Small Resource Sharing Network. Australian Computer Journal 10(4): 145-152.

In recent years there has been a rapid growth in the development and implementation of networks to achieve efficient sharing of geographically distributed computer resources. It is the purpose of this paper to detail an approach which, using available performance data on existing networks, derives an optimum topology for a network interconnecting the computer facilities of Australian research institutions.

Peady, G. W. and Pascoe, R. S. V. (1984). Using the UNIX System on the AAEC Network. Australian Computer Journal 16(1): 22-26.

An outline is given of the Australian Energy Commission computer network which connects the many computers at the Lucas Heights Research Laboratories. This network allows high speed data transfer between any two connected computers. A description is given of the software interface which allows communication between processes running under the UNIX timesharing system and other computers on the network. The need for easy communication with the network is essential as, although the protocols required are quite complex, they should not concern users. This paper shows how the complexities involved can be hidden in the system handling software, allowing the user ease of programming the network in a high level language yet retaining the complete flexibility offered by the network.

Pearcey, T. (1968). The Problem of Speech Recognition by Computer. Australian Computer Journal 1(2): 100-108.

Although this paper is largely of the nature of a review, it attempts to illustrate the fact that the achievement of successful speech recognition depends upon two processes: first, an analysis of the physical wave-form of speech and, second, the application of linguistic processes. It is considered that certain of the various components of speech are only partially resolvable by analytical methods and that the application of lexical, syntactic, semantic and contextual rules of the known language of the speech will be needed to resolve most or all of the ambiguities resulting from the physical analysis. Human speech consists of a sequence of basic sounds or phonemes, each possessing some distinctive features which in detail make them audibly distinct. However, the set of phonemes for the English language may be classified into a definite set of groups depending upon the major characteristics their frequency-time spectra and, in some cases, phonemes may be uniquely distinguished. In other cases differences are slight and unique identification is difficult to achieve and result in some ambiguities. The need for on-line speech recognition will be manifest as large general-purpose computer-based utilities bocome practicable and processing of the acoustic signal becomes possible with data handling rates greater than those currently available.

Pearcey, T. (1972). Distributed Computer Systems. Australian Computer Journal 4(1): 3-11.

Multiple access from a large number of terminals to a powerful central computer poses serious problems in attaining efficient operation. This paper proposes a computer system architecture based on the partitioning of the operation into three functional modules, (i) processing, (ii) storage and file management, and (iii) communications. The corresponding hardware configuration is hierarchical and highly modular and should result in efficient operation of the powerful central processor and provide for easy expansion.

Pearcey, T. (1974). The Effect of Large Scale Integration and Batch Fabrication on the Architecture of Large Data Systems. Australian Computer Journal 6(2): 61-70.

The effect of the development of large scale integration and general batch fabrication technology, is related to the effect it will have on the development of hardware architecture of large scale on-line data systems. In particular, it will improve processing rates and access rates to data and the more ready and quicker access to archival data. It will also allow improvements in reliability and the maintenance of integrity and improvement of recovery processes. A large improvement will be due to the ready availability of large scale associative storage devices at various locations in the system.

Pedersen, D., Riis, K. and Pedersen, T. B. (2002). A Powerful and SQL-Compatible Data Model and Query Language for OLAP. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Penny, J. P. (1977). A Simple Model for Input-Output and Compute Overlap. Australian Computer Journal 9(2): 72-76.

A simple analytic model is derived to show an upper bound on the improvement in throughput achievable by concurrent operation of resources. The model is considered useful particularly to provide a framework for simulation aimed at assessing the performance of a range of simple system configurations in processing a variety of workloads. An example is given where the model is used as an adjunct to a simulation of the effects of incore buffering and spooling through disc.

Penny, J. P., Ashton, P. J. and Tripp, D. G. (1988). Instrumenting Systems to Measure Components of Interactive Response Times. Australian Computer Journal 20(2): 79-84.

A formal model is presented of a procedure for measuring system responsiveness, and breaking interactive response times into components to show where the delays occur. The model allows for a most flexible decomposition of response times, one that would measure the contributions to response times from using, or being queued for, any designated resources, singly or in any combinations. It is suggested that an implementation of the model would be very simple, if considered at the time of system design. The model has also provided insights found useful in adding experimental performance monitors to existing systems, and these monitors are described.

Penny, J. P. and Sheedy, C. R. (1980). Measurement of Response Time Performance in Small Time-Sharing Systems. Australian Computer Journal 12(1): 15-22.

Measurement of response time performance for a time-sharing system is seen as a key step in a programme of performance evaluation and improvement. The difficulties of making such measurements are discussed. A description is given of an experiment in which response time has been measured from the execution time of a synthetic program which adapts its resource usage dynamically to match that of the current job mix.

Peramunetilleke, D. and Wong, R. K. (2002). Currency Exchange Rate Forecasting From News Headlines. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Pervan, G. and Phua, R. (1997). A Survey of the State of Executive Information Systems in Large Australian Organisations. Australian Computer Journal 29(2): 64-73.

Executive information systems (EIS) are still a relatively new phenomenon and problems still exist in their development and implemention. In Australia, little research into EIS has been conducted. This study has attempted to paint a picture of the state of EIS in Australia today, particularly in large organisations. EIS managers and executive users in the largest organisations in Australia revealed that relatively few EIS were fully operational though there had been an increaSe in the past five years and many were now under development and implementition. The study has examined the extent and type of executive usage, approaches to development, important development problems, the reasons for needing EIS, impacts of EIS, executive attitudes to IT arising from EIS experiences, the relative importance of organisational and technical issues, and reasons why EIS failure might arise. Comparisons with a previous Australian study reveal greater EIS penetration, a change in platform from mainframe/terminal to PC network, mixed development strategies, similar executive usage times, and a shift in perceptions from technical to organisational issues. Further comparisons with recent US studies also reveal similar executive usage times, similar emphasis on addressing esecutive's information requirements and not on technical issues, and similar perceptions of causes of failure, but longer development times for Australian EIS.

Peters III, J. F. (1993). Reasoning About Real-Time Systems. Australian Computer Journal 25(4): 135-148.

This paper explores how a special class of finite state automata called Typed Timed Input/output Automata (tTAi/os) can be used to reason about the behaviour of processes in a real-time system. A tTAi/o is a predicate automaton useful in specifying and reasoning about realtime systems. The typing discipline suggested for predicate automata is in the tradition of Martin-Lof's theory of types. A type is defined by prescribing how to construct an object of that type. A fragment of Girard's linear logic is used in classifying state types. An illustration of the use of tTAi/os in specifying a light-controller is presented. A partial abstract program is extracted during a proof of an automaton property for the light-controller.

Petrucci, L., Kristensen, L. M., Billington, J. and Qureshi, Z. H. (2002). Towards Formal Specification and Analysis of Avionics Mission Systems. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Pfeiffer, M. and Leaney, J. (1995). The Simple Reliable Monitor: A Formalisation of the Concept of a Safe Software Monitor. Australian Computer Journal 27(1): 9-15.

The (safety ) monitor concept has been proposed as a method of bounding brilliant and creative software with something a little more provable in order to keep one's feet on the ground and planes in the air. In this paper the monitor concept is extended to the simple, reliable (SR) monitor. The SR monitor may be seen as an alternative to n-version programming. The nth version of the system is the most sophisticated, the n-1 version is functionally similar, but more reliable, etc. At any time, M versions (N, N-1, N-2,... ) of the system are running, with a lower version providing the ultimate outputs only if the postconditions of the higher version fail. More than this, from the point of view of failure of the most sophisticated version, one is running a lesser version which would have the advantage of giving a correct answer, albeit with some performance loss. This would seem a far more philosophically correct way to provide a fallback.

Philcox, R. (1981). Local Government Computing in the Geelong Region. Australian Computer Journal 13(3): 83-86.

A number of local government authorities in the Geelong area have increased their use of computers over the last decade. Although there is agreement that several of their application systems perform very similar tasks, any arrangements for pooling resources can be considered a problem which has yet to be solved.

Philippi, S. (2002). Life-Cycle Inheritance in Concurrent Object-Oriented Systems. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Phillips, C. and Kemp, E. (2002). In Support of User Interface Design in the Rational Unified Process. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Piekarski, W. and Thomas, B. H. (2002). The Tinmith System - Demonstrating New Techniques for Mobile Augmented Reality Modelling. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Plimmer, B. and Apperley, M. (2002). Computer-Aided Sketching to Capture Preliminary Design. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Pollard, J. P. (1970). Solution of Multigroup Neutron Flux Linear Equations. Australian Computer Journal 2(2): 50-54.

The Sokololov method of averaging functional corrections is adapted to solution of the multigroup neutron flux equation for an infinite homogeneous reactor system. Convergence of the usual iterative methods is improved using direct solution of an associated approximation for the neutron flux. Calculations undertaken show the method to be quicker than either the Gauss-Siedel method or the Gauss-Jordan direct method.

Pope, K. S. (1967). Comments on Some Legal Aspects of Data Processing by Computer. Australian Computer Journal 1(1): 7-14.

This paper was selected by the Council for the Award of the A.C.S. Lectureship for 1967. The present position concerning the recognition of computer output by the Courts is complex and unsatisfactory. Legal requirements in the field of criminal, civil and company law are examined and problems which arise are discussed in detail. Steps to be taken to safeguard the position of computer users are considered and current views as to the manner in which the validity of output may be demonstrated are criticised. Proposals are put forward as to possible lines of action to meet the needs which will emerge as a result of the developing use of computers within the community.

Pope, K. S. (1979). Systems Analysts and Cultural Lag. Australian Computer Journal 11(1): 21-26.

The cultural lag theory of anthropologists is applied to the role of the systems analyst. Changes in technology foreseen are related to the position of the end-user and his increasing significance in the determination and use of computer systems. The effect of increasing specialisation for data base and communications operations is discussed. It is suggested that such changes emphasise the need for the separation of the analysis from the design functions, and that the conventional systems analyst must abandon analysis in favour of design to survive.

Popple, J. (1991). Legal Expert Systems: The Inadequacy of a Rule-Based Approach. Australian Computer Journal 23(1): 11-16.

The two different categories of legal AI system are described, and legal analysis systems are chosen as objects of study. So-called judgement machines are discussed, but it is decided that research in legal AI systems would be best carried out in the area of legal expert systems. A model of legal reasoning is adopted, and two different methods of legal knowledge representation are examined: rule-based systems and case-based systems. It is argued that a rule-based approach to legal expert systems is inadequate given the requirements of lawyers and the nature of legal reasoning about cases. A new, eclectic approach is proposed, incorporating both rule-based and case-based knowledge representation. It is claimed that such an approach can form the basis of an effective and useful legal expert system.

Prabhakaran, N. and Falkenberg, E. (1988). Representation of Dynamic Features in a Conceptual Schema. Australian Computer Journal 20(3): 98-104.

Some of the current information modelling techniques have been studied and a comparative analysis of their dynamic aspects is presented. Most of these techniques are not suitable for describing both fact- and activity-oriented specifications in a convenient way. In order to achieve an integrated approach with respect to fact and activity orientation, we have chosen the primarily fact-oriented technique NIAM (Nijssen Information Analysis Method) and improved its representation of dynamic features. A generalised algorithm for transforming activity-oriented specifications from a Petri net, onto a NIAM conceptual schema is described and illustrated with an example.

Prabhakaran, N. and Vermeir, D. (1983). On the Generation of Database Schemata. Australian Computer Journal 15(4): 91-102.

A conceptual schema describes the semantics of the real world. The conceptual schema are implemented in an actual database system through its corresponding internal schema. The database schema, which is a subset of the internal schema, maintains the consistency of the database. A set of algorithms for the transformation of a conceptual schema into a database schema is presented.

Prime, C. (1977). An Integrated System for Administration of Managed Funds. Australian Computer Journal 9(4): 132-137.

This paper describes the design of a form of integrated system for a growing section of life office business. Previous piecemeal attempts to computerise this section of business had been made, and with the passing of time their operation was becoming more and more unwieldy. The query was frequently raised 'would it not be easier to administer such business manually?' At the same time it was clear that the manual work required was fast becoming prohibitive. One if the main problems with the older systems was seen to be lack of flexibility. Consequently, the new system as described in this paper, was designed aiming to introduce every possible flexibility.

Proctor, R. M. J., Baturo, A. R. and Cooper, T. J. (2002). Integrating Concrete and Virtual Materials in an Elementary Mathematics Classroom: A Case Study of Success with Fractions. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Pullan, W. (1996). A Direct Search Method Applied to a Molecular Structure Problem. Australian Computer Journal 28(4): 113-120.

In a previous paper, Benke and Skinner (1991) described a direct search method for locating the global optimum of a multimodal function. This search method used an adaptive probablistic algorithm and was suitable for any function of many variables subject to arbitrary constraints. This paper describes an extension to this search method which generally improves the rate of convergence to the global optimum. The effect of this extension is evaluated using a number of standard multimodal test functions and a molecular structure problem.

Pulo, K. J. (2001). Recursive Space Decompositions in Force-Directed Graph Drawing Algorithms. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Purchase, H. C., Colpoys, L., McGill, M., Carrington, D. and Britton, C. (2001). UML Class Diagram Syntax: An Empirical Study of Comprehension. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Purchase, H. C., McGill, M., Colpoys, L. and Carrington, D. (2001). Graph Drawing Aesthetics and the Comprehension of UML Class Diagrams: An Empirical Study. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Qu, X. and Yu, J. X. (1998). A Performance Study of Mobile TCP/IP Solutions. Australian Computer Journal 30(2): 53-64.

In current TCP/IP-based systems, the complexity of mobile communication stems from the IP routing and addressing schemes. Most of the existing solutions support mobile communications in either the link layer, the IP layer, or the TCP layer. We proposed a two-step mobile solution: the portability is supported in the IP layer, and the mobility is supported in the socket layer. In this paper, we conduct several simulation studies to analyse our two- step solution in comparison with the other existing mobile TCP/IP solutions, and we report on the results. The results demonstrate the effectiveness and necessity of our two- step mobile solution.

Quigley, A. J. (2001). Large Scale 3D Clustering and Abstraction. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Quinlan, J. R. (1980). An Introduction to Knowledge-Based Expert Systems. Australian Computer Journal 12(2): 56-62.

This tutorial paper discusses the concepts underlying knowledge-based systems, and shows how they differ from more conventional (algorithm-based) systems. Three principal dimensions are identified; the representation of knowledge, architectures for deploying knowledge, and techniques for acquiring knowledge. Key ideas are illustrated from a selection of current expert systems covering a wide range of applications.

Radi, O. (2002). The Impact of Computer Use on Literacy in Reading Comprehension and Vocabulary Skills. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Rahayu, J. W., Taniar, D. and Lu, X. (2002). Aggregation Query Model for OODBMS. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Rahwan, I., Kowalczyk, R. and Pham, H. H. (2002). Intelligent Agents for Automated One-to-Many e-Commerce Negotiation. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Rama, O. F., Winikoff, M., Padgham, L. and Harland, J. (2002). Applying Conflict Management Strategies in BDI Agents for Resource Management in Computational Grids. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Ramakrishna, M. V., Nepal, S. and Srivastava, P. K. (2002). A Heuristic Algorithm for Combining Fuzzy Results in Multimedia Databases. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Randolph, N., Morris, J. and Lee, G. (2002). A Generalised Spreadsheet Verification Methodology. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Rasiah, A. I. and Attikiouzel, Y. (1994). A Syntactic Approach to the Recognition of Common Cardiac Arrhythmias within a Single Ambulatory ECG Trace. Australian Computer Journal 26(3): 102-112.

A syntactic method to recognise common cardiac arrhythmias in electrocardiograms is presented. Unlike many traditional syntactic approaches to this problem, the lowest level of primitives are chosen to facilitate recognition of the syntax primitives. In this application, the classical set of orthogonal functions derived from the hermite family of functions are selected as the lowest level of primitives. The next level of primitives, collectively termed arrlets, which make up the syntax set,are then modelled as a series expansion of these orthonormal hermite basis functions. The orthogonality of the basis set allows the modelling of the arrlets, i.e. the determination of the series expansion coefficients, to be realised in a simple and unambiguous manner. All these considerations facilitate the recognition of the syntax primitives which traditionally involved untidy extraction procedures. By using as features, the series expansion coefficients and a spread term, a probabilistic neural network is then used to detect the various arrlets within an ECG trace. After the detection of arrlets, the ECG trace is said to be "annotated" in terms of these various arrlets. By parsing the annotations, various combinations of arrhythmias can then be easily identified by looking for their corresponding syntactic form.

Ratkowsky, D. A. and Lance, G. N. (1978). A Criterion for Determining the Number of Groups in a Classification. Australian Computer Journal 10(3).

A simple criterion is described herein for determining the number of groups in a numerical classification employing the three most commonly used attribute types, viz. Qualitatives. Multistates and Numericals. Calculation of the criterion is presently available on the CSIRO Computing Network as an adjunct to REMUL, a divisive program with terminal reallocation, but the criterion is not specific to that program and can be calculated from the groups obtained from any classificatory algorithm operating on one or more of the above attribute types.

Ravindran, B. and Hegazy, T. (2001). RBA: A Best Effort Resource Allocation Algorithm for Asynchronous Real-Time Distributed Systems. Journal of Research and Practice in Information Technology 33(2): 158-172. First Page.

We present a best effort resource allocation algorithm called RBA for asynchronous real-time distributed systems. The algorithm uses Jensen's benefit functions for expressing application timeliness requirements and proposes adaptation functions to describe the anticipated application workload during future time intervals. Furthermore, RBA considers an adaptation model where subtasks of application tasks may be replicated at run-time for sharing workload increases, and a real-time Ethernet system model where message collisions are deterministically resolved. Given such application, adaptation and system models, the algorithm's objective is to maximise aggregate application benefit and minimise aggregate missed deadline ratio. Since determining the optimal allocation is computationally intractable, RBA heuristically computes the number of replicas that are needed for task subtasks and their processor assignment such that the resulting allocation is as "close" as possible to the optimal allocation. We also experimentally study RBA's performance under different scheduling and routing algorithms. The experimental results reveal that RBA produces higher aggregate benefit and lower missed deadline ratio under DASA than when the RED algorithm is used for scheduling and routing.

Reddy, P. G., Bhalla, S. and Prasad, B. E. (1982). Reliable Concurrency Control and Crash-Recovery in Distributed Databases. Australian Computer Journal 14(4): 134-136.

A centralised concurrency control procedure of the type proposed by Kung (Kung and Robinson, 1979) has been proposed in this work for distributed databases. It is shown to be crash resistant. The proposed set-up considerably reduces transaction processing time and has added recovery and other advantages.

Reed, K. (1978). A Practical Method of Comparing Computer Bureau Costs. Australian Computer Journal 10(1): 3-10.

This paper presents a simple technique for comparing the computer usage accounting techniques on computer bureaux. The paper restricts itself to considering charges for CPU and I/O time. The technique allows different charging algorithms to be compared with varying precision, and allows assessment of the alternatives of hiring a complete installation and paying for each job according to the resources (cpu time, I/O time) used.

Reeker, L. H. (1980). Natural Language Programming and Natural Programming Languages. Australian Computer Journal 12(3): 89-93.

The idea of "natural language programming" has a good deal of superficial attractiveness, but it also raises a number of questions. The most important of these is what one means by "natural language programming", since the use of unfettered, everyday language is not feasible, for a number of reasons. Two approaches to moving toward the goal of more natural programming languages using natural language are discussed, and the second, or "bottom up" approach is advocated.

Rees, M. J. (2002). Evolving the Browser Towards a Standard User Interface Architecture. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Reeve, R. C. (1984). Trends in the Use of EDP Audit Techniques. Australian Computer Journal 16(2): 42-47.

This paper presents the results of a survey undertaken to establish the current use of EDP audit techniques in external auditing in Australia, of computer based accounting systems and expected trends in such use over the next two years. A distinction is made between large and small computer systems. In particular the relationship between current use of particular EDP audit techniques and expected trends in such use is investigated.

Rehesaar, H. (1997). An Improved Paradigm for the Development of International Standards. Australian Computer Journal 29(2): 48-56.

The International Standards for Information Technology are developed by a Joint Technical Committee, JTCI, of the International Organisation for Standardization (ISO) and the International Electrotechnical Committee (IEC). To assist in the technical work of developing standards, JTCI has produced a set of Procedures Manuals. This paper examines these procedures and identifies problem areas for their implementation. The effects of these problems can be minimised with due care given to management issues. Using as a basis the develpoment of one particular standard - the Definition of Functional Size Measurement, within ISO/IEC JTCI WG 12 - an improved developmental paradigm is proposed.

Reid, T. A. (1981). Network Developments at the WA Regional Computing Centre 1965-1980. Australian Computer Journal 13(2): 46-51.

This paper describes the developments which have taken place at WARCC in data communications over the period 1965-80, culminating in the implementation of a multi-host, heterogeneous packet-switched network, with a gateway to national and overseas networks.

Renouf, D. W. and Henderson-Sellers, B. (1996). Tutorial Paper: Towards a Role-Based Framework Approach for User Interfaces. Australian Computer Journal 28(3): 96-106.

A role-based framework approach to software development focuses on the interaction of actors with an application. It links closely with the identification of use cases as well as the underlying core information model with which the actors will ultimately be interacting. In essence, such an approach endorses the benefits of an application viewpoint. We identify techniques and suggestions for implementing a role-based framework approach using customised application framework components.

Richards, A. G. (1976). Assessment of System Performance in Computer Selection Evaluations. Australian Computer Journal 8(1): 19-24.

This paper discusses techniques for assessing system performance as part of the overall proposal evaluation and computer system selection procedure, and suggests guidelines for choosing an appropriate technique according to the circumstances of particular procurements.

Richardson, D. J. (1969). A Generalised Computer to Computer Link for an IBM 360 Computer. Australian Computer Journal 1(5): 273-276.

The properties of a generalised computer to computer link for an IBM 360 computer are presented. A novel feature of this link is its ability to appear simultaneously like many different standard devices to an IBM 360 computer. The need for this type of link arose from a desire to make a variety of non-IBM devices, connected to a computer network including an IBM 360 computer, readily available to IBM 360 programmers.

Richardson, D. J. (1971). The AAEC Computer Network Design. Australian Computer Journal 3(2): 55-59.

The central computing system at the Australian Atomic Energy Commission's Research Establishment is currently on an IBM 360 model 50 computer. Twelve smaller digital computers and one analogue computer are in use at various points within a half-mile radius of the central computer installation. This paper describes plans to link a number of these computers into a network connected to the central computer, and outlines the philosophy behind the setting up of this network.

Riedl, N. F. (1987). A Checklist of Factors to be Considered when Negotiating Software Agreements. Australian Computer Journal 19(4): 206-214.

In this article guidance is offered to potential software purchasers concerning the nature of agreements that should be made with vendors. Although the author is not legally trained, many of the recommendations flow from discussions with professional legal persons and from negotiations with vendors. Although the checklist and guidelines were developed for academic institutions, slight modification should render them appropriate to your commercial or government group.

Rine, D. C. (1975). Multivalued Logic in Programming and Flowcharting. Australian Computer Journal 7(2): 75-79.

This paper identifies advantages of multiple-valued logics in programming and flowcharting. Aspects considered, aside from history and formulation, are compilation, conciseness and readability, extensibility, algebra structure, assembler code, deductive systems, and hybrid systems.

Ristuccia, R. M. and Searle, J. R. (1985). A Comparison of MYCIN and INFERNO as Reasoning Mechanisms. Australian Computer Journal 17(1): 14-19.

Expert Systems have been described over the last decade which can match, or even better, the performance of qualified experts in particular fields We present a feasibility study which compares the architectures and plausible reasoning mechanisms of MYCIN and INFERNO, In a medical Expert System which is required to diagnose thyroid disorders using laboratory data. The INFERNO reasoning mechanism is a better solution for our application, especially with its techniques for handling dependent data and for inconsistent evidence. However, since it does not make any assumptions, the conclusions it draws are weaker than those of MYCIN. Some design aims were not satisfied by either architecture.

Roantree, M. (2002). Metadata Management in Federated Multimedia Systems. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Roberts Jnr., C. E. (1982). Variable Order, Variable Stepsize, Componentwise Integration. Australian Computer Journal 14(1): 19-25.

A variable order, variable step, multistep, Adams predictor-corrector technique for componentwise integration is presented. Using this technique, each component of a system of ordinary differential equations to be integrated may have a different order and may take a different step size. Numerical results are given for two systems which arise from physical problems and for which being able to take different step sizes for different components leads to significant computational savings. These results are compared with those obtained from a standard well-known procedure.

Roberts, P. and Webber, J. (1999). Visual Truth in the Digital Age: Towards a Protocol for Image Ethics. Australian Computer Journal 31(3): 78-82.

The old adage 'seeing is believing' was once applied to the reliability of photographic evidence and a trust in photojournalism's reputation for truth and objectivity. From photography's beginnings, however, the technical capacity to alter images has been available and practised, but manipulations then were easy to detect. Advances in computer technology make the alterations of photographs and other images mostly invisible, and image manipulation is sometimes applied by advertisers in deceiving the consumer,and by newspaper editors in influencing their readers, matters which challenge the ethics of photojournalism. Further concerns arise from the copyright and ownership of images, for the easy and mostly undetectable manipulation of photographs and other images renders the ownership of this artwork difficult to identify and protect. The ease of image manipulation in the digital age requires the establishment of an ethical protocol for the guidance of practitioners and consumers. This paper describes the development and application of such a protocol in a higher education multimedia program.

Robinson, D. E. and Knight, P. C. (1987). Image Processing in Diagnostic Ultrasound. Australian Computer Journal 19(3): 161-166.

Diagnostic ultrasound relies on images of soft tissue parts of the body obtained from a pulse-echo technique using sound waves in the range of 2 to 10 MHz. Image processing techniques may be employed on the final image, but have found greater application when applied to the raw data before the image is constructed and in the image construction process. This processing aims to use data from the signals which is discarded in the image forming process, or to improve resolution and image quality. The theory of ultrasonic pulse-echo imaging is described with particular reference to the non-linear processing commonly used which impacts on the application of signal and image processing techniques. Applications of signal processing for image construction and tissue characterisation are described.

Robinson, I. (1975). On the Exit Criteria for the Romberg Integration Scheme - A Pragmatic Approach. Australian Computer Journal 7(3): 113-115.

An alternative termination scheme for the Romberg integration procedure is presented. Use of this new scheme in place of the standard test on successive diagonal elements results in an overall improvement in both the efficiency and reliability of Romberg's method.

Robinson, I. (1976). An Algorithm for Automatic Integration Using the Adaptive Gaussian Technique. Australian Computer Journal 8(3): 106-115.

An improved version of the adaptive Gaussian method for automatic numerical integration is presented. The extensions involve the implementation of a new order of subdivision and the use of an extrapolation step on each subinterval created by the method. The resulting algorithm is both reliable and efficient, particularly for integrating functions with a singularity at one or more points of the integration interval.

Robinson, I. G. (1971). Adaptive Gaussian Integration. Australian Computer Journal 3(3): 126-129.

An efficient method of using Gaussian quadrature formulae in an adaptive integration scheme is developed. It is shown that this method is extremely efficient and reliable and compares very favourably with other adaptive routines.

Robinson, M. A. (1981). A Review of Data Base Query Languages. Australian Computer Journal 13(4): 143-159.

Generalised query languages are becoming more popular. This paper describes the features available in query languages, and compares a number of these languages indicating whether they provide the described features.

Robson, J. M. (1979). The Height of Binary Search Trees. Australian Computer Journal 11(4): 151-153.

The height of binary search trees constructed from randomly ordered inputs is of interest where recursive algorithms are applied to such trees. Analytic results are presented showing that the average height of an n-node tree is probably of the form cln(n)+o(ln(n)) for some c between 3.63 and 4.31. Experiments equivalent to constructing a large number of trees suggests that c is close to 4 and that the standard deviation is small.

Roddick, J. F. (1991). Dynamically Changing Schemas within Database Models. Australian Computer Journal 23(3): 105-109.

Temporal support within database systems has been identified as a useful characteristic. We investigate the incorporation of temporal support into the meta-database and argue that useful semantic capabilities can be gained. The addition of this temporal support is investigated with particular reference to the semantics of null values, its effect on integrity constraints and its impact on query languages.

Roddick, J. F. and Nieuwenhuis, A. L. (2002). Application Rates to Undergraduate Programs in Information Technology in Australian Universities. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Rosenberg, B. (1971). Character Blurring. Australian Computer Journal 3(1): 43-46.

When a character is printed the ink may diffuse and produce a blurred representation. Further analysis of the character is then prevented unless the underlying shape is recovered. An operation is presented here which reverses the diffusion process and displays the underlying structure.

Roughan, J. L., Hough, G. and Gwatking, J. C. (1975). Computer Generation of Privacy Transformations. Australian Computer Journal 7(2): 58-64.

This paper discuses reversible transformations to be applied to data in a computer to prevent unauthorized access to the data. Two methods of transformation or encryption are discussed. The first can be used to encrypt data for sequential storage or transmission. The second method is suitable for number generators, combined in a carefully designed way, to encrypt the data. Decryption is achieved by simply repeating the process.

Rout, T. P. (1992). Quality, Culture and Education in Software Engineering. Australian Computer Journal 24(3): 86-91.

Techniques for the construction of quality software have been well known for many years, and their benefits in terms of product quality and programmer productivity have been well documented. Despite this, their use in commercial software production remains limited. It is suggested that the main reasons for this are cultural, and that the current processes of computer science education act to reinforce this culture. Some changes in emphasis in educational courses are suggested which may facilitate a change in culture.

Routledge, N., Bird, L. and Goodchild, A. (2002). UML and XML Schema. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Ruting, W. M. and Allen, M. W. (1972). Design of a Computer for System's Research Australian Computer Journal 4(3): 135-142.

A description is given of the background considerations, system structure, logical organisation, and hardware implementation of a high speed 16 bit computer designed for use in experimental work associated with investigations in computer architecture. The intended application has required emphasis in flexibility, extensibility, modularity and speed.

Ryan, D. M. (1979). Design of a Distributed System: Interprocess Communication. Australian Computer Journal 11(3): 103-107.

The design of intra host interprocess communication is given. Its integration with the standard input and output facilities of the host operating system is emphasised. This is the basis of the distributed system.

Ryan, D. M. (1979). Design of a Distributed System: Overview of System. Australian Computer Journal 11(3): 98-102.

This paper gives the basics on which a distributed system can be built. Emphasis will be placed on the role of interprocess communication in distributed systems. The actual design steps for a particular distributed system, based on an already existing system, will be given.

Sachdeva, P. (1985). DAMP - a Diagnostic System for Architectural Moisture Damage Problems. Australian Computer Journal 17(1): 27-32.

An experimental expert system for diagnosing moisture damage related problems in various types of buildings has been developed. The main objective behind the development of this prototype system was to increase understanding of inference engines and knowledge acquisition from experts. This paper discusses in detail how the expert system was developed and how it is stored.

Sacks-Davis, R. (1975). A Real Norm-Reducing Jacobi-Type Eigenvalue Algorithm. Australian Computer Journal 7(2): 65-69.

A norm-reducing Jacobi type algorithm for finding the eigenvalues and eigenvectors of an arbitrary real matrix is derived and shown to be an extension of Eberlein's algorithm. Numerical results are given and a comparison with Eberlein's algorithm is made.

Sager, M. T. (1988). Data Centred Enterprise Modelling Methodologies - A Study of Practice and Potential. Australian Computer Journal 20(3): 145-150.

Data centred enterprise modelling methodologies are a family of techniques to define, build and exploit enterprise-wide data models. Their part and current stages of development (database design, data analysis, information analysis and information strategy planning) and expected future stages (methodology refinement, system building automation and knowledge engineering) are described. Case examples from business and government illustrate the current application of data centred enterprise modelling methodologies to information planning problems in objective clarification, system planning, system specification, organisational impact and software selection.

Sajjanhar, A. and Lu, G. (1997). A Grid-Based Shape Indexing and Retrieval Method. Australian Computer Journal 29(4): 131-140.

One of the content based image retrieval techniques is the shape based technique which allows users to ask for objects similar in shape to a query object. We propose a novel method for shape representation and similarity measure which we call the grid based method. We shall evaluate its performance by comparing it with two popular methods, namely, the Fourier descriptors method and the moment invariants method. The comparative study is done by performing the same queries on the same database for all the methods. We also test the methods for robustness to noise by performing the queries on a database of noisy shapes. Experimental results show that the method proposed performs favourably compared with the other two methods.

Sale, A. (1975). The Basic Principles of Well-Structured Code. Australian Computer Journal 7(3): 116-126.

This tutorial paper sets out the basic principles underlying the concepts of well structured code, and the reasoning behind these principles. The alleged advantages of well-structured coding include increased programmer productivity, less debugging, etc., and it is therefore of potential interest to a wide range of computer professionals and users. The general topic of structured programming is also discussed to put well-structured code into perspective in the overall concept.

Sale, A. (1978). Stylistics in Languages with Compound Statements. Australian Computer Journal 10(2): 58-59.

This short communication discusses a stylistic problem which arises in languages, such as PASCAL, which use both statement separators, such as semicolons, and begin-end bracketting structures. It suggests that an alternative to the traditional rules which have evolved from Algol 60 is preferable.

Sale, A. (2001). Broadband Internet Access in Regional Australia. Journal of Research and Practice in Information Technology 33(4): 346-355. First Page.

Sale, A. H. and Bromley, A. G. (1975). A Real-Time Three-Dimensional Graphics Display. Australian Computer Journal 7(1): 15-20.

The visible surface problem for three dimensional objects is examined from a global point of view in which planar surfaces derived from convex three dimensional objects are regarded as the natural display elements. By retaining global information on surface and object relationships it is possible to considerably simplify the resolution of visible surfaces for a large class of realistic objects. Implementation of this approach suggests a display in which surfaces written to the display device can overlay and obscure previous picture information in the manner of oil painting. A display system is proposed in which this is implemented by a large buffer memory which holds a complete point-by point description of the picture in low cost MOS shift-registers. By combining new data to be entered into the memory in a variety of ways with the data already present, it is possible to considerably enhance the display's capabilities. The buffer memory also allows an easy match of the display system to conventional (TV) video equipment.

Sale, A. H. J. (1976). Computing as a Human Activity. Australian Computer Journal 8(3): 51-60.

This paper is the slightly edited text of the inaugural lecture given in Hobart, Burnie and Launceston in August 1975 by the Foundation Professor of Information Science at the University of Tasmania. It addresses the role of humans in computing and explores the areas of: Computers and people: social issues; people and computers: the computing industry; computers and awareness: introspective insights; and the rewards of computing communication and achievement.

Sale, A. H. J. (1977). Primitive Data Types. Australian Computer Journal 9(2): 63-71.

This tutorial paper is addressed primarily to practising programmers, and only secondarily to language designers, compiler writers and machine designers. It has two purposes: To bring some of the concepts of primitive (indivisible) data-types to the attention of the industry-at-large showing how our understanding of the fundamental processes and objects of programming is gradually improving, with some insights of my own, and To emphasise that programmers ought to think in terms of well-structured concepts, and that when and if one of the less attractive and archaic computing languages has to be used, then it is better to translate thoughts into the concrete forms required leaving plenty of traces of the original intentions. In other words, do not write in a language, think and then code into it.

Sale, A. H. J. (1987). Optimization Across Module Boundaries. Australian Computer Journal 19(3): 167-173.

Languages which provide separate compilation features through the module or package concept (such as Modula-2 and Ada) have some little-known problems with maintaining integrity and also achieving optimizations that cross the module boundaries. This paper addresses these questions using Modula-2 as the example language, and proposes a number of different methods of constructing Modula-2 processors (systems that run Modula-2 programs) which have properties different from the conventional structure of such processors.

Sale, A. H. J. (1989). The Architecture of the PCM-1. Australian Computer Journal 21(2): 71-78.

This paper describes the architecture of the PCM-1 processor. This processor is the first of a series to be designed and constructed within the Parallel Combinator Machine (PCM) Project at the University of Tasmania. The PCM-1 is a 50 Mips single chip uniprocessor and is designed to explore some of the basic architectural issues of graph reduction processors and to provide for the performance evaluation of architectures for executing functional and logic languages.

Sale, A. H. J. (1989). The RISC Style of Architecture. Australian Computer Journal 21(3): 97-99.

In this short tutorial paper the RISC style of computer architecture is discussed. Consequences of the style are brought out, together with the reasons for its relatively recent appearance in commercially available processors.

Sale, A. H. J. and Kewley, D. J. (1981). Remarks on "A Comparison Between PASCAL, FORTRAN and PL/1" (With Author's Reply). Australian Computer Journal 13(3): 97-98.

The remarks in this communication relate to a paper in the February 1981 issue of the ACJ, by D.J. Kewley. A plea is made for more accurate titling of papers, and the usual sophistication level of PASCAL compilers is discussed.

Sammut, C. A. (1985). Concept Development for Expert System Knowledge Bases. Australian Computer Journal 17(1): 49-55.

An important goal of research in Artificial Intelligence (AI) is to design learning programs which are capable of automatically acquiring knowledge. Many of the techniques developed in the field of machine learning are useful in applications such as the acquisition of knowledge for databases and expert systems A brief review of some research in machine learning is given. We then describe a program which interacts with a human trainer, acquiring expert knowledge by asking him questions. Learning begins when the trainer shows the program an example of the concept to be learned. The program determines which parts of the example belong to concepts stored in memory. A description of a new concept is formed by using the information obtained from the memory to generalize the description of the training example. The generalized description is tested when the program constructs new examples and shows these to the trainer, asking if they belong to the target concept.

Sammut, C. A. and Sammut, R. A. (1983). The Implementation of UNSW-PROLOG. Australian Computer Journal 15(2): 58-64.

Early Prolog interpreters were based on techniques derived from the field of automatic theorem proving. These systems developed ways of implementing some of the more important features of the language, i.e. pattern directed invocation of procedures and automatic backtracking. Since the first Prolog system, a considerable amount of research has been devoted to creating more efficient interpreters and compilers. This paper discusses some of the more important aspects in the implementation of the Prolog interpreter, Written and now used at the University of new South Wales.

Sammut, R. A. and Sammut, C. A. (1983). PROLOG: A Tutorial Introduction. Australian Computer Journal 15(2): 42-51.

PROLOG is a programming language based on predicate logic. Since its first implementation approximately ten years ago, it has found application in a variety of "symbol processing" areas such as natural language processing, deductive information retrieval, compiler writing, symbolic algebra, computer aided design and robot problem-solving. This paper introduces the fundamental concepts which are unique to programming in PROLOG by developing and analysing a series of small programs for deductive information retrieval, the solution of the "N-queens" problem and a simple exercise in computer aided design.

Sanderson, J. G. (1967). A Basis For a Theory of Programming Languages. Australian Computer Journal 1(1): 21-27.

Four conditions are considered in order to arrive at a mathematical model of a programming language: the model must represent the fact that the result of a computation is fully determined by its program and data; it must be able to define the syntax and semantics of a language; and it must agree with the theory of compatibility. A model, 'The computable language', is derived which meets these conditions. Simulation, translation, semantics, syntax and a number of related concepts are defined in terms of this model and their properties are discussed. The merits of the model as a possible basis for a theory of programming languages are considered.

Sandy, G. A. (2001). The Online Services Bill: Theories and Evidence of Pornographic Harm. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

On the 1 January 2000, the Broadcasting Services Amendment (Online Services) Bill 1999 came into force. It aims to censor online what is currently censored offline. Information Technology Professionals should be concerned about censorship of the internet both in their capacity as a member of the profession and as a citizen. The Bill is mainly aimed at pornographic content, and how a society treats it is a good test of its openness. The paper addresses the primary research question - "Is censorship of internet pornography justified?" Five theories about pornographic harm are distilled from an analysis of a multi-disciplinary literature, including the parliamentary debates on the Bill, and the hearings of the Senate Select Committee on Information Technologies. The research findings on pornographic harm are also summarised. The conclusion of the analysis is that censorship of internet pornography by the Australian Government is not justified on three grounds. First, suppressing speech that is offensive to some members of society, even the majority, is inconsistent with free speech that characterises an open society. Second, the research findings do not support the view that pornography directly causes harm. Third, pornography may confer positive societal benefits for both men and woman.

Sauer, C. (1986). Programming Environments - Deskilling or Job-Enriching? Australian Computer Journal 18(2): 90-95.

The argument that developments in programming languages, methodology and work organisation have routinised and deskilled programming is outlined. The extent to which this argument may be applied to programming environments is examined. A case is established, but is then criticised through the recognition of ways in which they may enrich the programmer's work. It is concluded that the technology when applied in the context of routine software production does indeed have characteristics which may facilitate further the deskilling process.

Saunders, D. (1979). A Great Debate: "Does the Widespread Use of Computers Cause Unemployment"? Australian Computer Journal 11(2).

On Thursday, Feb. 15,1979, the Victorian Branch of the Australian Computer Society organized a debate with the above title. Speaking for the motion were John Maynes, Federal Pres. Of the Federated Clerks' Union, and Peter Nolan, Federal Sec. Of the Australian Council of Trade Unions. Those speaking against the motion were N.C.L.Batt, Deputy Premier and Treasurer of Tasmania and Federal Leader of the Australian Labor Party and Peter Frankel, Pres. Of the Melbourne Chamber of Commerce. This article reproduces (slightly edited version of ) the talks given by Maynes and Frankel. The general conclusions drawn by all speakers were that:- (i) Computers, (and other technological innovations) do cause loss of future employment opportunities. Data should be gathered to quantify this effect. (ii) Individuals in society, particularly young people, will have to accommodate themselves to achieving their affiliative, self actualisation and remuneration satisfaction with less time spent in formal work situations. (iii) Computers are here to stay and we should accept them and set about planning for changing societal structure so that all get a fair share of the wealth and happiness. (iv) Technological changes also bring new opportunities, which should be recognised, planned for and exploited. (v) Australian Computer Society members should be aware of and involved in the creation of new relationships between man and his employment.

Saunders, D. (1991). Comments on INFERNO. Australian Computer Journal 23(3): 93-94.

This short communication comments on the unconditional independence assumptions in INFERNO.

Saw, B. M. (1973). A Discussion of the Business Data Processing Cost/Benefit Relationship. Australian Computer Journal 5(1): 35-38.

This paper discusses a set of resource variables which can be controlled by the EDP Project Manager. It looks at the components of Total Project Cost and considers how these components cause direct and indirect changes to cost. It also makes recommendations on how to influence the project environment in order to reduce absolute cost or to maximise benefits for a preset resource level.

Sawyer, M. and Baird, A. H. (1985). Computer Technology in Child Psychiatry Services. Australian Computer Journal 17(3): 140-142.

This paper reviews the potential benefits that computer technology offers child and adolescent psychiatry services in Australia. As well it describes a research project being developed by the authors, which is designed to evaluate self-administered computer aided interviews in a child psychiatry clinic.

Schkolnick, M. and Sorenson, P. (1982). The Effects of Denormalisation on Database Performance. Australian Computer Journal 14(1): 12-18.

The introduction of normalised relations in the design of a relational data base gives rise to potential performance problems in its implementation. In this paper, we describe a technique to materialise join relations, examine the question of program transformation in support of this technique and present an example of a data base design using it. The example shows the power of this design method.

Schmidt, H. (2002). Compositional Software Architecture Definition. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Scuse, D. H. (1982). Data Base Interfaces. Australian Computer Journal 14(2): 71-74.

This paper describes how the dependence of systems of application programs on data base management systems can be lessened by placing a software interface between the application system and the data base management system. The interface makes the design and implementation of the application system easier by supporting more sophisticated data models and more complex data manipulation than are normally supported by the data base management system, and can also be used to increase the control that the data base administrator has on the data base environment.

Searle, G. and Ward, R. (2002). Funktion Zusammen: Two Schools, One Class and German LOTE in Rural Queensland. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Self, J. A. (1977). Artificial Intelligence Techniques in Computer Assisted Instruction. Australian Computer Journal 9(3): 118-127.

Artificial intelligence research should have much to offer to computer-assisted instruction. This article surveys some recent attempts to apply artificial intelligence techniques to develop more sophisticated computer-assisted instruction systems. The topics covered include representing knowledge, problem-solving, psychological modelling, learning and communicating. While many of the applications are only in demonstration systems and often do not take full advantage of the results of artificial intelligence research, there is clear evidence of progress towards more 'intelligent' computer-based teaching systems.

Shanks, G. and Darke, P. (1998). Understanding Data Quality in a Data Warehouse. Australian Computer Journal 30(4): 122-128.

Data quality has long been recognised as a keyfactor in the success of data warehousing. Attempts to define data quality typically provide lists of quality dimensions that are vaguely defined, overlapping and not based in sound underlying theory. One promising approach is to define quality dimensions in ontological foundations. This paper presents an alternative approach that uses semiotic theory to develop a framework for understanding data (the content) and metadata (the structure) quality in a data warehouse. Goals of data and metadata quality are separated from the means of achieving them and ways of measuring them. Existing data and metadata quality dimensions are analysed and placed within the framework. The framework provides researchers and practitioners with a sound, theoretically-based set of quality goals, means and measures which will support further work in the development of data and metadata quality guidelines, evaluation procedures and empirical studies of data and metadata quality in practice.

Shepherd, R. and McConnel, R. E. (1971). Some Aspects of the Solution of Equations of Motion Using Numerical Integration Techniques. Australian Computer Journal 3(1): 20-28.

Some techniques applicable in numerical integration solutions of the equations of motion of simple spring mass systems are reviewed, particular aspects relevant to the use of the methods in digital computation are outlined and results of applying the various approaches in a computer program designed to determine the response of a single degree of freedom system to time varying excitation are compared. It is concluded that if the integration time step interval is sufficiently small and if sufficient significant figures are used in the calculations, the more involved techniques provide little practical advantage.

Shin, D. and Koh, K. (2002). Optimizing Web Content Delivery Using Web Server Accelerator. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Shipman, A. L. (1987). Implementing Relaxation Labelling with Neural Networks. Australian Computer Journal 19(3): 140-147.

This paper describes how neural network models can be used to solve a simple relaxation labelling problem as might arise in image understanding applications. These models have the advantages of being highly parallel, very fast and tolerant of hardware faults. A neural architecture is developed consisting of coupled associative memories each implemented with a neural network. Simulation results are presented to show the solution of the example problem under ideal and adverse conditions where the inputs are corrupted by noise. A method for preventing spurious stable states in the neural network models is proposed.

Shortridge, J. D. (1977). Development of a Bibliographic Search System Using FORDATA. Australian Computer Journal 9(4): 150-154.

The design of a family of databases, to be used in a retrospective literature search system currently being implemented by the CSIRO Central Library, is described.

Sifer, M. (2002). Querying Web Site Visitor Trend Data with Coordinated Nested Bar and Pie Charts. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Sifer, M., Peres, Y. and Maarek, Y. (2002). A Grammer View for Editing Structured Documents. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Sifer, M. and Potter, J. (1996). Structured Graphs: A Visual Formalism for Scalable Graph Based CASE Tools. Australian Computer Journal 28(1): 13-26.

This paper introduces a structured graph formalism for the visualisation of software designs. Structured graphs have their origins in structured analysis data flow diagrams. The formalism supports the abstraction of large complex networks with browsing and editing operations. These operations are scalable; as a structured graph increases in size the number of user steps to browse and edit remains the same. Both top-down and bottom-up editing are supported.

Simsion, G. C. (1989). A Structured Approach to Data Modelling. Australian Computer Journal 21(3): 108-117.

A levelled approach to the development and presentation of Entity Models is described. The approach is based on generalisation and specialisation (supertyping and subtyping) of entities to produce models at different levels of genericism. The multi-level representation is shown to have practical application in bringing to light alternative schema designs, and highlighting trade-offs between schema stability and enforcement of constraints.

Simsion, G. C. and Symington, J. A. (1981). A Comparison of Network and Relational Data Base Architectures in a Commercial Environment. Australian Computer Journal 18(4): 122-126.

A number of DBMSs provide both Network and Indexing facilities. By using the Indexing facilities alone, a pseudo-Relational Database can be produced. Such a data base has advantages in terms of simplicity, flexibility, and data independence over Network implementations, but it is likely to be unacceptably inefficient. Experience has shown that a satisfactory compromise can be achieved by combining structures from the two models. The database designed first using only Indexed access then enhanced by the addition of Network constructs in areas of potential inefficiency.

Singh, A. and Billington, J. (2002). Creating an Internet Inter-ORB Protocol Service Specification. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Sitzmann, I. and Stuckey, P. (2002). Compacting Discriminator Information for Spatial Trees. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Skabar, A. and Cloete, I. (2002). Neural Networks and Financial Trading and the Efficient Markets Hypothesis. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Slade, G. and Parker, N. (1994). SEE-Ada: Software Evaluation Environment for Ada. Australian Computer Journal 26(4): 143-150.

The SEE-Ada tool has been developed to allow the graphical display of the dependency structures of large Ada systems. SEE-Ada uses an Oracle relational database and can import any metric data, capable of conversion to the SEE-Ada standard format. Metric data loaded into SEE-Ada can be displayed with graphical user interface techniques allowing the user ready access to any of the loaded metric data. Integration with the Ada quality metrics analysis tool, AdaMAT/D, is provided. The use of SEE-Ada as an independent Validation and Verification tool and as an automated Ada development support tool is discussed.

Slay, H., Phillips, M., Vernik, R. and Thomas, B. (2001). Interaction Modes for Augmented Reality Visualization. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

Slay, H., Thomas, B. and Vernik, R. (2002). Tangible User Interaction Using Augmented Reality. In Proc. Third Australasian User Interface Conference (AUIC2002), Melbourne, Australia, Grundy, J. and Calder, P., Eds., ACS. Full Text.

Smiley, D. H. (1979). Process Standardisation in Information Systems Engineering. Australian Computer Journal 11(2): 42-47.

This paper summarises the "software crisis" and its main implications. The preoccupation of Software Engineering with methodology and the neglect of its standardisation and metrology is noted. A possible professional framework for DP practitioners, with new emphasis on standardisation and metrology is outlined. The construction of a software laboratory and its use in process standardisation are described.

Smirnov, A. D. and Bun'kov, N. G. (1975). Planning of Processing for a Partially Determined Problem Flow in the Mixed Mode of Batch Processing and Time Sharing. Australian Computer Journal 7(2): 80-84.

An algorithm for planning of processing for a partially determined flow of problems in time sharing systems is proposed. Optimal forming the levels of priority is introduced. The influence of the number of priority levels on the system response time is investigated, and a method is proposed are made which provides a guarantee of processing a job (problem) for the given time. The tradeoffs of different algorithms for time sharing processing are made, and the influence of system structure and parameters on system performances is investigated for the time sharing mode of operation by means of a simulation model.

Smith, A. G. (1981). Attitudes Towards Computers: a Survey of Diverse Persons. Australian Computer Journal 13(3): 87-92.

A 40 item Likert attitude instrument, measuring attitude towards computers in society, was constructed and administered to a sample of 414 people in Newcastle NSW. The instrument is shown to discriminate people on the basis of attitude towards computers. The nature of a positive versus a negative attitude is examined. Respondents were further studied in five groups, from keen computer users to strongly negative opponents, and some implications of their attitudes for education programmes and for further research are discussed.

Smith, B. W. (1968). The Economic Impact of Computer-Based Technological Change. Australian Computer Journal 1(2): 63-77.

This paper attempts a critical assessment of some of the widely varying views expressed in the last decade or so on the economic effects of technological development, especially development based on the computer. While the more extreme radical views (such as Wiener's) would seem to be wrong in predicting long-term technological unemployment, the conservative viewpoint expressed by Australian Government spokesmen and others is unduly optimistic about the short-term structural effects of innovation. The major needs to minimise the disruption resulting from technological change are seen to lie mainly in education and cooperative planning, together with a willingness by society to change both its attitudes and its institutions. Finally, an attempt is made to forecast some possible socio-economic changes which may result from the computer and other modern technologies.

Smith, B. W. (1969). The 1968 ACS Membership Survey. Australian Computer Journal 1(4): 219-236.

The Australian Computer Society conducted a survey of its members in 1968 to obtain information relating to the professional interests, experience, qualifications, conditions of employment and views of the Society's policy and program. The principal results obtained in the survey are discussed in the paper. These should not only be of value in planning the activities of the Society, but should also be of some interest as they comprise the most detailed information currently available of staff engaged in the computer field in Australia.

Smith, G. (1969). Some Guidelines For The Design of Primary Data Vetting Programs. Australian Computer Journal 1(4): 194-200.

Now that sorting and reporting programs are so often generated by computer, the primary data vetting program is becoming one of the most frequently written distinct classes of program for commercial computer work. The paper describes the characteristics of primary data vetting programs, discusses problems which should be considered by the designer of such programs, and suggests solutions to many of the problems.

Smith, G. (1986). A FORTRAN Input Program Generator. Australian Computer Journal 18(3): 106-114.

Many FORTRAN programs have poor user-interfaces because input data streams have complex structures which cannot adequately be cast into rigid, fixed field format. This paper describes the ideas underlying INPROG, a FORTRAN input program generator which facilitates the use of more natural free-form data structures. From a simple description of the input data structure, the program generator constructs a program that will: input the data; check that data conform to the required structure; report errors when appropriate; and invoke specified FORTRAN statements when prescribed elements are recognised in the input data stream. INPROG is designed to be easy for FORTRAN programmers to use. A useful set of data element types is presented, and comprehensive error handling procedures are described.

Smith, G. (2002). Specifying Mode Requirements of Embedded Systems. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Smith, J. L. (1972). Data Base Organisation for an Array Processor. Australian Computer Journal 4(3): 98-103.

Computers have great potential to provide logical manipulation of information.Efforts to date in developing this facility have largely resulted in the provision of procedural languages designed to interface with the structural level of data, with a few notable exceptions for limited applications.The prospects of large data banks accessed with problem-oriented languages seem to be limited by conventional computer architecture.Array processors now offer a very powerful implementation tool for such data base languages.In this paper the problem of representing information in computers and some recently proposed models are discussed.Relevant characteristics of the recently announced CDC STAR computer are used to illustrate potential advantages in certain representations of relational information.

Smith, J. L. (1979). Alternatives in the Architecture and Design of Distributed Data Bases. Australian Computer Journal 11(1): 5-12.

A large number of alternatives exist in the architecture of distributed data base management systems and in distributed design. This paper classifies some basic system characteristics for which independent distribution strategies can be defined. Three possible global logical architectures are described. The ANSI SPARC architecture for centralised database management systems is used as a basis. Finally some indication of the control problem for distributed databases is given.

Smith, M. G. (1970). The Terminal in the Terminal-Oriented System. Australian Computer Journal 2(4): 160-165.

The terminal of the 1970's is pictured as an increasingly important component in data processing systems, both economically and functionally. Technological and economic factors influencing future terminal design are presented, including rationales supporting the emergence of the A/N display terminal as the "workhorse" terminal of the future.

Smyrk, J. R. (1985). A Model for Office Automation Delivery Systems. Australian Computer Journal 17(3): 102-105.

This paper places Office Automation into a framework of four information technology delivery vehicles linked as a "global architecture". Since the other three components (Data Processing, Management Information and Decision Support) are often treated as variants of office automation by various authors, they too are defined and discussed. The model assembled in this way has some implications for the management of information technology in organisations. These implications are discussed and elaborated.

Smyth, R. L. (1979). Patterns of DBMS Use and Experience in Australia. Australian Computer Journal 11(4): 154-158.

The paper describes the results of a survey of patterns of DBMS use and experience in a group of large Australian organisations. These results indicate that DBMS is not as important in support of data management or MIS as is often claimed. DBMS often fails to provide a great measure of data independence, and DBMS selection is often highly subjective. The results obtained are compared with those of similar surveys carried out in the U.S. Suggestions as to the likely or desirable future developments in DBMS technology are also made on the basis of the information derived through the survey.

Soliman, M. I. and Sedukhin, S. G. (2002). Trident: A Scalable Architecture for Scalar, Vector and Matrix Operations. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Somogyi, S. and Brown, A. (1975). A Computer Implementation of Actuarial Notation. Australian Computer Journal 7(1): 21-25.

This paper is a case study of an attempt to implement Actuarial Notation as an extension of the PL/I programming language. Recently an actuarial publication language was proposed which may be suitable for direct use as computer input but is not suitable for direct use in a computer program without modification. It is feasible to transform this publication language by a system of rules into a form acceptable to a compiler. The paper discusses the practical difficulties encountered in the implementation of a programming system based upon the transformed Notation.

Sonntag, B. and Colnet, D. (2002). Lisaac: the power of simplicity at work for operating system. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Speiser, A. P. (1967). IFIP -Its Structure and its Aims. Australian Computer Journal 1(1): 54-56.

The International Federation for Information Processing (IFIP) was born out of the computer revolution. This revolution is far more than the introduction of the electronic computer into the engineering and mathematical world, as was originally anticipated. It consists of the penetration of digital machines into almost every activity, be it human or mechanical, where formally encoded information (so-called data) has to be handled or processed in any way. Besides the more obvious fields such as accounting and scheduling, the computer is taking over more and more subjects previously considered to be the exclusive domain of the human mind. Computers are now programmed to translate languages, to compose music, and the term "artificial intelligence" aptly describes a discipline of research which attempts to find out how far machines can ultimately penetrate into the area of human mental activity.

Spence, E. (2001). Cosmopolitanism and the Internet. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Spinczyk, O., Gal, A. and Schroder-Preikschat, W. (2002). AspectC++: An Aspect-Oriented Extension to the C++ Programming Language. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Srinivasan, U., Gu, L., Tsui, K. and Simpson-Young, W. G. (1997). A Data Model to Support Content-Based Search in Digital Video Libraries. Australian Computer Journal 29(4): 141-147.

This paper describes a video data model that can be used to represent structural and semantic characteristics of videos in a video database. The structural characteristics are determined using video analysis techniques to identify camera shots within the video and characteristics of each shot such as camera motion. This information is stored in conjunction with semantic characteristics determined from shotlists and transcripts. The paper also discusses how this video data model supports the querying and browsing of video content in video databases.

Stager, G. S. (2002). Computationally-Rich Constructionism and At-Risk Learners. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Stanton, R. B. and Mackensie, H. G. (1987). A Graphics Oriented Deductive Planning System. Australian Computer Journal 19(2).

This paper describes a deductive approach to 'region use' planning problems. The planning task is viewed as one of devising a complete set of policy rules by iteratively modifying the rules and making their deductive consequences readily available to the planner. The approach is being explored on four fronts; rule forms for expressing policy and associated reasoning strategies; detection rule set completeness; efficient spatial inferencing techniques over large databases; and interactive graphics services tightly coupled to the deduction processes. An application of this approach to a National Park region zoning problem is described.

Stasko, J. T. and McCrickard, D. S. (1995). Real Clock Time Animation Support for Developing Software Visualisations. Australian Computer Journal 27(4): 118-128.

Developers building software visualisations must use a graphics library and user interface toolkit as an underlying support platform. Often, these support environments are large, difficult to learn, low-level, and lacking primitives for capabilities such as animation. We have developed a graphics support environment called Polka-RC for building software visualisation. Polka-RC is a second generation system that leverages the continuous animation primitives of the mature system Polka, and adds the capability of specifying real clock time-based animation activations and durations. The new Polka-RC animation model also provides a flexible multiprocess program-to-visualisation mapping. In this article we describe the Polka-RC methodology list advantages of the approach and describe how the methodology infleunces the design of software visualisations and algorithm animations.

Stearn, A. E. and Ly, N. G. (1983). A Simple Technique for Scaling Data Arrays. Australian Computer Journal 15(3): 112-114.

Scaling data transformation of data arrays with specific applications to computer graphics and microprocessor control systems are discussed. An algorithm is deduced which requires only integer addition and subtraction. Where data repeats are required, an additional multiplication is executed on initialisation of the algorithm.

Steel, M. A. (1981). Automating the Restructuring of Network Data Bases. Australian Computer Journal 13(4): 109-113.

An algorithm for unloading and reloading network data bases is described. Although the method is applicable generally to network databases, CODASYL terminology is used. A program capable of generating commented COBOL unload and reload programs from schema definitions is outlined. Types of restruxturing that can be handled automatically are listed, as also are types that can be handled with a small amount of modification to the generated programs.

Stoegerer, J. K. (1984). A Comprehensive Approach to Specification Languages. Australian Computer Journal 16(1): 2-8.

Specification languages in their various forms provide a basis for a formalised, well engineered specification process and a foundation for the application of computerised tools. Due to their application within the development process three major types of specification languages - requirements specification languages (RSL), design specification languages (DSL) and program design languages (PDL) are distinguished. Three major goals for specification languages are postulated from which a comprehensive set of principles is derived. Finally we give a very short overview of the most important specification languages and propose some likely future directions.

Stokes, J. (2002). Developing Generic Attributes in a Pre-service Primary Teacher Education Course. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Stokes, J. (2002). Towards Knowledge Age Teachers: Reflective Practitioners. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Suffern, K. G. (1984). Contouring Functions of Two Variables. Australian Computer Journal 16(3): 102-106.

An efficient method is presented for contouring continuous twice differentiable functions of two variables. This method traces the individual contours by constructing a succession of points on the contour, where curvature information at each point is used to locate the position of the next point. This contour tracing part of the method is a development of a technique discussed by Schagen (1982). A coarse set of grid lines is used to detect the individual contour lines. The method is suitable for contouring analytic functions whose value and derivatives are readily computed, and for contouring regularly distributed or randomly scattered value only data, provided a continuous twice differentiable global interpolating function can be computed.

Suffern, K. G. (1990). An Octree Algorithm for Displaying Implicitly Defined Mathematical Functions. Australian Computer Journal 22(1): 2-10.

An octree based algorithm is presented for displaying perspective wireframe views of implicitly defined mathematical functions of three variables f(x,y,z)=0. Functions of this form represent surfaces in three dimensional space and an adaptive bilevel subdivision scheme is used in which the viewing volume is subdivided into octants of uniform size to search for the surface, and those octants that contain the surface are further subdivided for plotting purposes.

Swatman, P. A., Swatman, P. M. C. and Everett, J. E. (1990). Stages of Growth of an Innovative Software House: An Additional Criterion for Software Package Selection. Australian Computer Journal 22(3): 89-98.

As software becomes more crucial to organisational success, there is a tendency to turn towards third-party software houses for cheaper, faster and more effective solutions. This paper discusses the problems encountered by small suppliers, offering innovative software solutions to industry. It suggests that there is a common pattern to the development of such suppliers, and proposes a model of their evolution and development. This model, in turn, identifies a fairly consistent set of issues which should be addressed by organisations purchasing such innovative, strategic software products. The paper provides an appropriate criterion for judging the likely success of products purchased from such a software house, additional to the standard criteria of product quality and suitability.

Swatman, P. M. C. and Everett, J. E. (1991). Australian Involvement in Electronic Data Interchange - 1989. Australian Computer Journal 23(1): 22-33.

Interest in the subject of inter-organisational information systems in general and Electronic Data Interchange (EDI) in particular has grown significantly over the past two years. This paper reports a survey of companies using and contemplating the use of Electronic Data Interchange systems in Australia. The survey investigates the level and type of participation in EDI schemes, and relates these to industry categories and company characteristics.

Tallis, G. M., Shaw, D. E., Williams, J. and Sarfaty, G. (1970). Discriminant Analysis By Computer. Australian Computer Journal 2(1): 3-8.

Tandianus, J. E., Chandra, A. and Jin, J. S. (2002). Video Cataloguing and Browsing. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Tari, Z. and Hamidjadja, H. (2002). A CORBA Cooperative Cache Approach with Popularity Admission and Routing Mechanism. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Taylor, A. A. (1972). Professionalism and Apathy. Australian Computer Journal 4(3): 104-111.

This paper is addressed to members of the ACS and to anyone who is actively concerned in or with the computing industry. For some time one of the aims of the ACS has been to raise the status of membership to the point where Corporate Membership would be acceptable to employers and to the public at large. The first part of this paper attempts to set out in a brief history of the Society what has occurred towards this end and to highlight some of the present controversies and problems. In the second part the attitude and performance of programmers and the apparent indi.0fference of members of the Society to the Society's aims are examined and contrasted with what one might expect of a professional programmer. Suggestions for improving the performance of programmers and professional standards are offered.

Tehrani, S. and Nijssen, G. M. (1985). UCL: A User-Friendly Conceptual Language. Australian Computer Journal 17(4): 174-180.

A User-friendly Conceptual Language (UCL) and translator based on the conceptual information model NIAM have been developed at the Department of Computer Science of the University of Queensland, Australia. This system takes advantage of the linguistic conceptual information embedded in the conceptual schema in interpreting the user's queries. The structure of UCL is described and the salient features of this language are outlined with a set of queries.

Temperly, J. F. (1968). On the Handling of a Particular Data Structure. Australian Computer Journal 1(3): 166-168.

This paper gives some details of and discusses a solution to the problem of storing on disc and gaining random access to a file of records with a non-trivial structure. Programs making use of the file are written in FORTRAN. Attempts to solve the problem were initiated by a request for assistance from the Department of Astronomy of the Australian National University. The problem became a preoccupation of a number of programmers before this solution was attempted and successfully completed.

Thangarajah, J., Padgham, L. and Harland, J. (2002). Representation and Reasoning for Goals in BDI Agents. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Theerachetmongkol, A. and Montgomery, A. Y. (1980). Semantic Integrity Constraints in the Query by Example Data Base Management Language. Australian Computer Journal 12(1): 28-42.

This paper firstly describes a method of modelling the real world within a data base using a model similar to the Entity Relationship Model. Some constraints that occur in the real world are defined. The main body of the paper describes the method of describing these semantic integrity constraints in the Query By Example Language. A very complete set of examples illustrate the nature and specifacation of the various constraints identified as being desirable.

Thom, J. A., Kent, A. J. and Sacks-Davis, R. (1991). TQL: A Nested Relational Query Language. Australian Computer Journal 23(2): 53-65.

This paper provides an introduction to nested relational databases and surveys some of the languages used by these databases. Formal algebra and calculus have been developed for nested relational databases as well as a number of practical query languages, such as SQLINF, NF2, SQL/W and TQL. TQL is the data definition, data manipulation and query language used by the Titan+ information management system. The main features of TQL include support of text attributes, tuples, nested tables and implicit joins using references.

Thom, J. A. and Thorne, P. G. (1983). Privacy Legislation and the Right of Access. Australian Computer Journal 15(4): 145-150.

The right of individuals to access information concerning them is an element of virtually all privacy legislation. This right is generally regarded as a prime safeguard of personal privacy. This paper raises issues fundamental to the definition, implementation and enforcement of the "right of access" principle. As a consequence of developments in database technology compliance with this principle may, in many cases, be infeasible.

Thorne, F. (1999). Costs and Benefits of Reuse. Australian Computer Journal 31(1): 1-8.

Reuse will increase the quality of our computer systems and staff productivity during development and maintenance phases. Reuse does not occur for free - we must manage the costs of creation, usage and support, along with changing our practices so that reuse is not just part of a utopian vision but a day to day activity throughout the development process. Measurement of reuse levels, staff trained and/or specialising in reuse, software support for the process of reuse and economic models to justify reuse are a few tools available in breaking down the barriers to reuse.

Thornton, B. S., Bloomell, C. and Thornton, F. (1994). Comparison of Centralised and Decentralised CT Radiology Services using Separated Scan Heads, IT and High Speed Communication Links - A New Telemedicine Study. Australian Computer Journal 26(3): 82-89.

A service based comparative study is made of centralised CT scan facilities servicing a region with a system of distributed separated CT scan heads in the region with data collection transmitted to a centralised CT image processing system from which telemedicine assessments are then made between the central and remote sites. The service advantages for patients, resource utilisation advantages and staffing flexibility from such a decentralised system are possible with current economically justified information technology equipment and high speed communication links.

Thornton, B. S. and Lee, J. K. (1993). Dynamic Complexity Parameters for Software/Operating System Interaction During Developments or Re-engineering. Australian Computer Journal 25(3): 98-104.

Several parameters which are dynamic metrics related to output response from a program during software or platform changes and re-engineering can be derived from a class of adaptive feedback model. Transfer function methods can be used to relate the observed changes in the level of output response to changes made in software processing activity level of step function types when inserting, removing or changing subsections of a program. This idea has arisen from the development, testing, modification and re-engineering of a program over a number of years on mainframes to remove programming and structural weaknesses and improve the quality of the software. The parameters depend on the characteristics of the software changes and the level of software/hardware interaction with the operating system. They cannot be expressed explicitly in these terms but are indicators of the interaction of complexity of software being developed and of the levels of maintenance expertise likely to be required. They are dynamic metrics and are complementary to the usual static complexity metrics based on the coding itself. They can also be used to compare different operating systems in their interaction with a software project and/or with changes in hardware.

Thornton, B. S., Park, T. M., Goddard, J. and Hughes, J. M. (1988). Staffing and Training Implications of Australian Software Export Targets. Australian Computer Journal 20(4): 161-167.

An input-output table for Australia including the software industry (for the first time) has been constructed and used to investigate outcomes of the Federal Government's targets for Australian software exports. Approximately four times as much is spent on software as hardware and software is s prime factor in selling hardware. Software could become one of Australia's largest export earners. However, the level of trained software personnel required to achieve the Government's targets has not previously been quantified nor have the effects on other industry sectors been assessed as has been done herein. The results of the paper indicate that an increase in software staff from approximately 12,000 to 23,000 would be required to increase Australian exports from the current $100 million p.a. level to $500 million p.a. The training implications are discussed but no clear solution is apparent and the problem would be greater to meet the Government's eventual targets of $1000 million and $1500 million p.a. under present educational resources and industry training.

Thornton, B. S., Todter, C., Botten, L. and Caden, M. (1987). Moire Fringe Methods in Aerofoil Sail Shape Measurement for the "Kookaburra" 12-Metre Yachts. Australian Computer Journal 19(3): 115-118.

Optimum aerofoil shape of cross sections of a sail is necessary to achieve maximum power in events such as the America's Cup for 12-metre racing yachts. The projection of black speed stripes on a sail viewed as narrowed strip images by a CCD camera at mast height provides a vision system to display this shape for visual assessment or actual aerofoil parameter measurement. However, unavoidable lighting conditions, shadows and reflections cause severe degradation at the leading and trailing sections of the aerofoil and this prevents measurement of chord length and other key parameters. A new method of image enhancement of the aerofoil strip images is being developed using Moire fringes and an on-board personal computer. Problems and results of several experiments for the "Kookaburra" 12-metre yachts are presented.

Tognetti, K. (1974). On the Graphical Representation of a Queue. Australian Computer Journal 6(1): 30-33.

A discrete formulation of a queuing process is offered which serves as the basis for describing the instantaneous behaviour of a queue. Such a formulation as well as being in a form for easy programming also leads to the quantity service load which if displayed graphically exhibits simultaneously all the important dynamic parameters very succinctly.

Tognetti, K. P. and Brett, C. (1972). SIMSCRIPT II and SIMULA '67 - A Comparison. Australian Computer Journal 4(2): 50-57.

This paper compares and contrasts the high level discrete simulation languages SIMSCRIPT II (IBM 360/50 installation) and SIMULA '67 (Control Data 3300 installation) through a tutorial exposition. It is shown that although SIMCCRIT II has a powerful language structure, better readability and excellent documentation, the implementation of SIMULA '67 for both compilation and execution is superior to SIMSCRIPT II at this stage.

Topor, R. W., Keddis, T. and Wright, D. W. (1985). Deductive Database Tools. Australian Computer Journal 17(4): 163-173.

A deductive database is a database in which data can be represented both explicitly by facts and implicitly by general rules. The use of typed first order logic as a definition and manipulation language for such deductive databases is advocated and illustrated by examples. Such a language has a well-understood theory and provides a uniform notation for data, queries, integrity constraints, views and programs, We present algorithms for implementing domains, for using atoms with named attributes, for evaluating queries, and for checking integrity constraints. The implementation is by translation into Prolog and can be performed using a standard Prolog system. The paper assumes some familiarity with relational databases, logic and Prolog.

Trcek, D. and Blazic, B. J. (1997). Certification Authorities in a Global Network - Procedures and Guidelines for a Public Key Infrastructure. Australian Computer Journal 29(2): 41-47.

Public key technology is the most natural and convenient way for key management in a global network, which in turn depends on a certification infrastructure. Its properties and behaviour should prevent threats. Moreover the infrastructure should be efficiently manageable and it should meet users' expectations regarding trust. Flexible guidelines and procedures are given in this paper, where all certification infrastructure security issues are logically structured. Thus it is easier to understand and to find possible solutions in an easier way.

Trinidad, S. (2002). A Journey of Networking Learners Down Under: A Reflection of the Evolution of ICT in Western Australian Primary Schools. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Tse, T. H. (1985). An Automation of Jackson's Structured Programming. Australian Computer Journal 17(4): 154-162.

A program development system has been written based on Jackson's structured programming methodology. It accepts input and output data structures and generates pseudo-code. Executable operations other than computations can be generated automatically. The number of input and output data structures can be unlimited since they can be accepted in turn by the system. Backtracking is solved by accepting 'quit if' operations in the data structures. The system also supports program inversion, which is essential for structure clash and for multi-user interactive systems.

Tse, T. H. (1986). Integrating the Structured Analysis and Design Models: an Initial Algebra Approach. Australian Computer Journal 18(3): 121-127.

Numerous models have been proposed under the name of structured systems analysis and design. Because of the lack of a common theoretical framework, the transition from one model to another is arbitrary and can only be done manually. An initial algebra approach is proposed to integrate the structured models. The algebra defined can be mapped through homomorphisms to Yourdon structure charts and DeMarco data flow diagrams. It can also be linked to Jackson structure text through equations.

Tse, T. H. (1987). Integrating the Structured Analysis and Design Models: a Category-Theoretic Approach. Australian Computer Journal 19(1): 25-31.

a number of models have been proposed under the name of structured analysis and design. It has been pointed out, that there is no common theoretical framework among them. Transformation of a specification from one model to another, although often recommended by authors, can only be done manually. A category-theoretic approach is proposed in this paper. As a result, development of structured specifications can be assisted through structured tasks and morphisms, and the integration of structured models can be achieved through functors and free categories.

Tse, T. H. and Pong, L. (1982). A Review of System Development Systems. Australian Computer Journal 14(3): 99-109.

The requirements for a system development system are defined and used as guidelines to review six such systems: SAMM, SREM, SADT, ADS/SODA, PSL/PSA and Systematics. It is found that current system development systems emphasise only validation and user verification. They can perform relatively little on automatic file organisation and maintenance.

Turner, P. J. (1982). A Disk Based Observing System for a Radio Telescope. Australian Computer Journal 14(1): 32-34.

We discuss the design requirements for software capable of performing astronomical observations on a large transit radio telescope. We describe simple but flexible real-time software which is capable of automatically scheduling a variety of types of astronomical observations and maintenance tests. The use of user compiled and edited data bases allows flexible and easy specification of observational parameters. A separate scheduling and observing program structure gives users freedom in designing observing programs and eliminates system supervisory overheads during real-time observations.

Turpin, A. and Smyth, W. F. (2002). An Approach to Phrase Selection for Offline Data Compression. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Uitdenbogerd, A. L. and Zobel, J. (2002). Music Ranking Techniques Evaluated. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Underwood, J. and McMahon, A. M. (1978). Teaching Systems Concepts Using a Hospital Admissions Model. Australian Computer Journal 10(2): 53-57.

The paper describes the construction of a model for use in teaching systems thinking to students of administration. A hospital was used as an example and an admissions and discharge unit were modelled. The aim was to demonstrate feedback, equilibrium and stability in the system.

Urting, D., Berbers, Y., Baelen, S. V., Holvoet, T., Vandewoude, Y. and Rigole, P. (2002). A Tool for Component Based Design of Embedded Software. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Vaghani, J., Ramamohanarao, K., Kemp, D. B., Somogyi, Z. and Stuckey, P. J. (1991). An Introduction to the Aditi Deductive Database System. Australian Computer Journal 23(1): 37-52.

Vallance, S. and Calder, P. (2002). Multi-Perspective Images for Visualisation. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Valluri, S. R., Vadapalli, S. and Karlapalem, K. (2002). View Relevance Driven Materialized View Selection in Data Warehousing Environment. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

van Bommel, P. (1993). A Randomised Schema Mutator for Evolutionary Database Optimisation. Australian Computer Journal 25(2): 61-69.

In this paper we focus on randomised evolutionary optimisation. We introduce a general framework for the optimisation of data models, based on the concept of evolution. This evolution is guided by a randomised schema mutator. Although our approach is expressed in terms of database optimisation, our ideas are applicable to other fields of randomised evolutionary optimisation of computer models, especially when similar (graph structured) models are used.

van der Knijff, D. J. J. (1978). Software Physics and Program Analysis. Australian Computer Journal 10(3): 82-86.

Software Physics is a term used to describe the analysis of programs to extract software engineering measures from particular general properties of the programs. It may be used to compare programs and languages, and to improve estimation procedures in the software industry. This paper introduces the reader to the terms used in Software Physics and its application to some problems. A selection of recent empirical analyses are presented to enable the reader to make comparisons with other methods.

Vasak, T. (1986). A Survey of Control Facilities in Logic Programming. Australian Computer Journal 18(3): 136-145.

One of the major problems in logic programming that needs to be overcome is the provision of control facilities more powerful than those currently available yet which preserve the declarative semantics of programs. The topic has been the subject of considerable research in recent years with many diverse approaches being taken. This survey provides a critical overview of these various attempts, highlighting their strengths and weaknesses.

Vaughan, F. A., Marlin, C. D. and Barter, C. J. (1988). Distributed Operating System Kernel for a Closely-Coupled Multiprocessor. Australian Computer Journal 20(2): 58-64.

This paper describes the experience of the authors in developing a distributed operating system kernel for a closely-coupled multiprocessor workstation prototype. The strategy adopted was to obtain the distributed V-System from Stanford University and then to develop a kernel to permit this system to run on our architecture. Since the V-System was developed on a loosely-coupled architecture, namely a network of Sun workstations connected via Ethernet, the experience described here highlights the difference between distributed kernels required for the two kinds of multiprocessor architecture.

Verheecke, B. and Straeten, R. V. D. (2002). Specifying and Implementing the Operational Use of Constraints in Object-Oriented Applications. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Vernik, R. J. and Turner, I. (1992). Techniques and Tools for Analysing Software Products. Australian Computer Journal 24(3): 98-105.

Software analysis can be a very labour-intensive task. For analysing large software systems, tool support is necessary. This paper details our experiences in analysing an Ada system with the assistance of various commercially available and in-house developed tools. Section 2 of this paper describes the tools and the basic environment used to assist our analysis. This is followed by a discussion of the general approach and techniques used, including the use of graphical structural representations of the software, analysis of source files using pattern matching and parsing techniques, and the use of metric data. Samples of our analysis results are presented in Section 4. These cover three of the major areas of interest to our customer: structure, quality and portability. We conclude by providing a summary of our experiences. We contend that for the analysis of large-scale systems, an integrated framework consisting of a central data repository is needed.

Verschoor, R. and Low, G. (1994). Software Reusability in Australia. Australian Computer Journal 26(4): 134-142.

While research has highlighted the potential of software reuse, little research has been undertaken to investigate the degree to which organisations are actively employing a policy of software reuse. In fact, some authors suggest that the paragigm of reuse has not been adopted, nor has it sufficiently benefited organisations at large. Various barriers to adopting a policy of software reuse have been suggested. Recent research has suggested non-technical barriers, such as managerial and measurement problems of reuse. The current research examines this change in emphasis by examining the experience of Australian organisations.

Vickers, T. N. (1986). Quokka : A Translator Generator Using Denotational Semantics. Australian Computer Journal 18(1): 9-17.

Translator generation is the automatic production of a translator from a formal specification of a language. Quokka is a translator generator that accepts a denotational definition of a programming language's semantics. Using this definition Quokka generates an independent program capable of translating programs into lambda expressions. The lambda expressions can then be interpreted by an implementation of the lambda calculus. Alternatively the lambda expressions may be translated into code suitable for execution on a conventional run-time stack. Lexical and syntactic properties of a specified language are defined in a manner compatible with existing lexical analyser and parser generators. Quokka is intended as a research and learning tool for experimentation in the fields of denotational semantics and programming language theory.

Vincent, J. (2002). MicroWorlds and the Integrated Brain. In Proc. WCCE2001 Australian Topics: Selected Papers from the Seventh World Conference on Computers in Education, Copenhagen, Denmark, McDougall, A., Murnane, J. and Chambers, D., Eds., ACS. Full Text.

Vossos, G., Dillon, T., Zeleznikow, J. and Taylor, G. (1991). The Use of Object Oriented Principles to Develop Intelligent Legal Reasoning Systems. Australian Computer Journal 23(1): 2-10.

The ability of object oriented systems to handle complex entities, inheritance, encapsulation, data abstraction and information exchange, data abstraction and information exchange provide powerful features for modelling many real world situations. We discuss the use of object oriented systems for modelling legal reasoning within two contexts namely (a) a tribunal or arbitration system and (b) a court based system. In the latter we propose the use of a combination of object oriented systems and case based reasoning. In particular, we discuss a prototype, IKBALS, which deals with applications for compensation under the Workcare Scheme of the Accident Compensation Act, 1985, The Intelligent Knowledge Based Legal System (IKBALS) is based on an object oriented approach utilizing a knowledge lattice in conjunction with meta-rules and rules. The system advises lawyers acting for injured workers on the likelihood of a successful application for weekly payments, lump sum entitlements or medical and like expenses.

Vowels, R. A. (1992). Division by 10. Australian Computer Journal 24(3): 81-85.

Division of a binary integer and a binary floating point mantissa by 10 can be performed with shifts and adds, yielding a significant improvement in hardware execution time, and in software execution time if no hardware divide instruction is available. Several algorithms are given, appropriate to specific machine word sizes, hardware and hardware instructions available, depending on whether a remainder is required. The integer division algorithms presented here contain a new strategy that produces the correct quotient directly. Without the need for the supplementary correction required of the previously published algorithms. The algorithms are competitive in time with binary coded decimal (BCD) divide by 10. Both the integer and floating point algorithms are an order of magnitude faster than conventional division.

Wadham, I. D. (1971). The World of MiniComputers. Australian Computer Journal 3(1): 35-42.

Mini-computers are becoming an important part of the general computer scene. Even so their potential is still largely unused in business computing. This paper discuses the important characteristics of mini-computers and provides a broad coverage of models which are available and well-supported in Australia, together with their sources of supply in Australia. It goes on to discuss current uses of mini-computers and to develop suggestions for future uses in the factory, office and large-computer environments.

Wagenhals, L. W., Haider, S. and Levis, A. H. (2002). Synthesizing Executable Models of Object Oriented Architectures. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Wahlstrom, K. and Roddick, J. F. (2001). On the Impact of Knowledge Discovery and Data Mining. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

Knowledge Discovery and Data Mining are powerful automated data analysis tools and they are predicted to become the most frequently used analytical tools in the near future. The rapid dissemination of these technologies calls for an urgent examination of their social impact. This paper identifies social issues arising from Knowledge Discovery (KD) and Data Mining (DM). An overview of these technologies is presented, followed by a detailed discussion of each issue. The paper's intention is to primarily illustrate the cultural context of each issue and, secondly, to describe the impact of KD and DM in each case. Existing solutions specific to each issue are identified and examined for feasibility and effectiveness, and a solution that provides a suitably contextually sensitive means for gathering and analysing sensitive data is proposed and briefly outlined. The paper concludes with a discussion of topics for further consideration.

Wallace, C. S. (1976). Transformed Rejection Generators for Gamma and Normal Pseudo-Random Variables. Australian Computer Journal 8(3): 103-105.

A combination of the transformation and rejection techniques for the generation of pseudo-random variates from specified distributions is presented. The method extends the rejection technique to cover distributions of infinite range and/or infinite density at some point in the range. Algorithms using the method are devised for the Normal distribution and for the Gamma distribution with shape parameter less than one. The first algorithm is competitive with others published, and the second superior to previous algorithms.

Wallace, C. S. (1977). Computing Research in Australia. Australian Computer Journal 9(1): 21-24.

If the papers published in the Australian Computer Journal and presented at the Australian Computer conferences since 1970 can be taken as a fair example of non-defence computer research in Australia, the state of research is not healthy. Although slightly over half the output comes from tertiary institutions, the overall flavour is one of small-scale efforts directed towards or spun off from short-term practical needs. The only area in which output resembles the pattern of overseas research is numerical analysis. Available data on the input to computing research shows a very low level of support in industry, government and universities. Given this minuscule effort the general quality of papers is quite creditable, but the quantity is small and the scope very limited. There is no sign of improvement in support for research over the years surveyed, and the implications for the future in Australia of this highly technological industry is gloomy.

Wallace, C. S. and Gupta, G. K. (1973). General Linear Multistep Methods to Solve Ordinary Differential Equations. Australian Computer Journal 5(2): 62-69.

This paper presents a formalism of the general m-step m-order linear multistep method for the numerical solution of ordinary differential equations such that the method may be represented by a polynomial of degree m. This formalism conveniently isolates the m degrees of freedom of the general multistep method. Expressions for the investigation of stability and truncation error have been obtained for this formalism, thus providing us with the tools to investigate new multistep methods. Also presented are some new stiffly-stable linear multistep methods.

Wallace, C. S. and Jessup, A. M. (1970). A Simple Graphic I/O Device. Australian Computer Journal 2(1): 39-40.

Wallington, C. E. (1968). Display Systems In Numerical Meteorological Experiments. Australian Computer Journal 1(3): 158-165.

As computer developments allow numerical meteorological research to become more complicated there is a growing need for display facilities for detailed inspection of atmospheric models and analysis of observations. Use of such facilities falls into three broad categories - (1) Experiments with methods of applying models that already have firm theoretical foundations, (2) Detection of suspected phenomena from coarse networks of data and (3) Probing the structure of new types of data.

Walsh, J. E. and Kelleher, G. J. (1970). Median Two-Person Game Theory and Examples of its Flexibility in Applications. Australian Computer Journal 2(3): 114-116.

This paper considers two-person game theory where the players choose their strategies independently. Use of mixed strategies introduces probabilistic aspects; so that the payoff to a player has a probability distribution. Determination of optimum strategies is simplified when only some reasonable " representative value" is considered for a distribution. The distribution mean is used for this purpose in expected-value game theory. Another reasonable choice is the distribution median, and this is the basis for median game theory. Pay-offs of a very general nature are allowable for median game theory (some play-offs may not even be numbers). Also optimum solutions are obtainable for virtually all games. These solutions are obtained through orderings of the outcomes of the game (pairs of payoffs, one to each player) according to desirability, with each player doing a separate ordering. This paper first provides an introduction to median game theory and then gives the generally applicable solution, which depends on choices of "relative desirability" functions by the two players (to order the outcomes). Finally, to illustrate the flexibility of median game theory, there is a discussion (including some examples) about considerations in selection of relative desirability functions.

Wang, C., Zhang, F. and Wang, Y. (2002). SAWT: A New System for Secure and Anonymous Web Transactions over the Internet. Journal of Research and Practice in Information Technology 34(1): 34-46. First Page.

This paper proposes a new kind of Secure Anonymous Web Transaction (SAWT) system for anonymous browsing and communication on the Web with high security. In the proposed system, normal users can surf or shop online anonymously while malicious accesses to a Web server can be traced and discovered. The latter property has not been achieved in other existing systems, which can bring greater fairness for both users and Web servers.

Wang, H., Cao, J. and Zhang, Y. (2002). Ticket-Based Service Access Scheme for Mobile Users. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Wang, H., Feng, D. and Huang, S.-C. (2001). A Statistical Method for Assessment of 3-D Medical Image Registration. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS.

Wang, H. C., Feng, D. D. and Jin, J. S. (2001). Cataloging and Search Engine for Video Library. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Wang, J., Maher, M. and Toper, R. (2002). Rewriting General Conjunctive Queries Using Views. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Wang, X. and Jin, J. S. (2002). A Quantitative Analysis for Decomposing Visual Signal of the Gaze Displacement. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Wang, X. Y., Feng, D. D. and Jin, J. S. (2002). Elastic Medical Image Registration Based on Image Intensity. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Warracke, J. I. and Carnegie, J. R. (1983). Perhaps Some Enlightenment and Re-Assurance About Our Jobs. Australian Computer Journal 15(4): 122-127.

This paper examines the social consequences of the introduction of information technology within the insurance industry. For the purposes of the paper the insurance industry is defined as including companies which conduct life insurance and/or general insurance business. The main thrust of the paper is directed toward examining the employment effects of technology applications within these sectors. Emphasis is placed on how technological change has affected employment levels, the employment structure and the quality of working life for employees. Our conclusions are essentially negative but for this we make no apology as our assessment is based on empirical evidence and personal observation.

Warren, B. and Brian, L. (1980). FACETS: A Language Feature for Security and Flexibility. Australian Computer Journal 12(4): 125-131.

Current designs in programming languages stress the need for data abstraction facilities. This paper views a data abstraction as one facet of the behaviour of its underlying data type. This facet hides the implementation details but presents a full view of allowable operations on objects associated with it. It is argued that, particularly in an environment where security is important, it is necessary to provide a facility for precisely defining other, more limited facets of the behaviour of a type. These can be used for fully controlling access to sensitive data. Language facilities for defining and using facets of both simple types and type combinations are developed in a Pascal environment. Various examples of 'safe' generic procedures and their use with sensitive data are presented.

Washizaki, H. and Fukazawa, Y. (2002). Dynamic Hierarchical Undo Facility in a Fine-Grained Component Environment. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Wasley, R. S. (1975). Learning to Live Together. Australian Computer Journal 7(3): 105-108.

An economic and informative data processing system in business as well as government today is basic to the operation of most organizational units. There are three groups of people who, by the nature of their responsibilities, are intimately involved in this. They are: (1) data processing personnel;(2) top management personnel; and (3) accounting personnel. To achieve the desired results, however, there must be the capacity within these three groups to attempt to understand the role which each of these functional areas has in the assembly and analysis of operating data. To date, there are many apparent examples where this is not the case.

Waters, P. and Leonard, P. G. (1990). The Lessons of Recent ECC and US Developments for Protection of Computer Software under Australian Law. Australian Computer Journal 22(4): 123-132.

The law needs to provide significant protection for computer software if programmers are to have the incentive to invest the considerable creative effort and resources required to develop new programs. On the other hand advances in the software industry are incremental, with new innovations building on past developments. This stepping stone progress in software development could be stifled if the legal protection of software was too extensive. Copyright law, which applies to computer software, endeavours to strike a balance between those competing policy goals by protecting the particular expression of an idea butt not protecting the idea itself. This article examines the difficulties in applying this abstract dichotomy to computer software. The Copyright Law review Committee is currently reviewing the legal protection of software. This article considers recent overseas developments in the legal protection of software, particularly the European Community's proposed Directive and recent US court cases.

Watkins, R. P. (1973). A Survey of Automatic Flowchart Generators. Australian Computer Journal 5(3): 132-140.

The value of flowcharts for documentation has led to many attempts to generate them automatically from computer programs. This survey examines the methods by which flowcharts can be constructed and considers whether the existing systems adequately satisfy the requirements of documentation.

Watkins, R. P. (1973). Towards a Theory of Documentation. Australian Computer Journal 5(2): 57-61.

The need for the standardization of documentation has been apparent for a long time, but this can only be achieved if an adequate definition of the concept of documentation exists. A possible definition is presented and its implications are discussed.

Watkins, R. P. (1974). The Design of Flog, an Automatic Flowchart Generator. Australian Computer Journal 6(3): 98-123.

This paper provides a detailed discussion of the design principles of an automatic flowchart generator and is a sequel to Watkins (1973b). FLOG produces high quality two-dimensional flowcharts from a graphical analysis of the source Fortran program. The paper commences with a theoretical study of flowchart design. This begins with an introduction to the linear notation used for graph representation and is followed by consideration of design criteria. These two areas lead to the development of theorems for flowchart segmentation. The second part of the paper is a description of the main features of FLOG, concentrating on the problems of segmentation and the construction of effective two-dimensional symbol layouts. The paper concludes with a critical discussion of faults of FLOG.

Watkins, R. P. (1974). The Design of Introductory Programming Subjects. Australian Computer Journal 6(2): 71-77.

Because a student's whole educational career can be influenced by his initial involvement with a discipline it seems necessary to expend a large amount of effort in the design and teaching of introductory subjects. Subject design involves the two complementary activities of content decision and subject documentation. This paper begins by discussing a method of subject documentation and goes on to apply it to Introductory Programming Subjects. In doing so it is argued that a greater degree of creative problem analysis should be included and that this seriously affects decisions about course content and presentation. The paper concludes by considering the implementation of these ideas and some problems which arise.

Watkins, R. P. (1982). Input-Output Systems in High-Level Languages, Part I - The Archaeology of Fortran and Algol. Australian Computer Journal 14(3): 77-90.

This paper provides a tutorial survey of input-output systems in Fortran and Algol 60. Although primarily an interpretive, historical study, it also brings into question some strongly held beliefs about the design of this aspect of high level languages.

Watkins, R. P. (1982). Input-Output Systems in High-Level Languages, Part II - Pascal and Basic. Australian Computer Journal 14(4): 122-133.

This paper contrasts two languages with different design philosophies and examines why the axiomatically based design of Pascal input-output fails when the pragmatically designed system of Basic succeeds.

Watkins, R. P. (1984). Modules in COBOL 83. Australian Computer Journal 16(3): 82-89.

An extremely simple change can be made to the draft proposed COBOL standard of 1983 to incorporate the concept of modules. One particular method of achieving this is defined which satisfies the twin requirements of constrained usage and no effect on any other aspect of the language definition.

Watson, D. F. (1985). Natural Neighbour Sorting. Australian Computer Journal 17(4): 189-193.

The natural neighbour order of a bivariate data set is established by finding all circles that pass through three or more of the data and such that no datum lies inside any circle. Two data are called natural neighbours if, and only if, they lie on the same circle. This unique order provides the basis for constructing the Delaunay and Voronoi tessellations. When the natural neighbour order is known, local subsets of data can be examined and local trends estimated for dependent functions. In this survey, natural neighbour order is described and several algorithms for natural neighbour sorting are summarized.

Watson, R. T. (1989). Key Issues in Information Systems Management: An Australian perspective - 1988. Australian Computer Journal 21(3): 118-129.

The results of a three-round Delphi study of a sample of IS managers of Australia's top 200 organisations indicate their perceptions of the most critical information systems management issues facing them over the next three to five years. Strategic planning for information systems is rated as the most important issue, closely followed by problems with recruiting and developing skilled information systems personnel and the development of an information architecture. The Australian findings are compared with similar studies in Europe and the United States. All of the top ten issues deal with managerial issues and focus primarily on the relationship between the IS department and the organisation. It is concluded that Australian managers must spend more time on managing the interface between the IS department and the organisation and that they must take the iniative in solving the shortagee of skilled information systems professionals.

Watson, R. T., Pitt, L. F. and Carey, N. (1990). Information Systems Technology in Support of Distribution: Some Australian Experiences. Australian Computer Journal 22(3): 99-110.

Information Systems Technology (IST) has a recognised role in creating and sustaining competitive advantage. This paper develops the link between distribution and the use of IST to improve competitive performance by setting forth a series of questions for stimulating thinking about distribution issues and by describing instances of organisations that are using computers to gain competitive advantage. The majority of the case studies are drawn from the Australian business environment.

Weber, R. (1986). Planning and Control Issues in End-User Computing. Australian Computer Journal 18(4): 159-165.

End-user computing is having an important impact on information system development within organisations. Like all technological developments, however, it needs to be carefully managed if its use is to be cost effective. Even with limited experience of end-user computing, some significant planning and control problems have emerged. This paper examines the nature of these problems and some of the reasons why they have arisen. It provides recommendations to assist managers to formulate standards in an end-user computing environment.

Webster, L. A. (1970). The Development of an Information System for a Manufacturing Company I : The Feasibility Study. Australian Computer Journal 2(2): 61-65.

Most companies have been involved at some time or other in a feasibility study. The success of such a Study can generally be measured by the action which follows. If this criterion is accepted then the study outlined in this paper was an outstanding success. The paper covers the period from when the Study was launched up to the time when Project Teams were formed to commence working on systems development.

Webster, L. A. (1971). The Development of an Information System for a Manufacturing Company II : An Order Entry System for a Steel Plant. Australian Computer Journal 3(1): 3-11.

This system has been developed and installed by John Lysaght (Australia) Limited at their Port Kembla computer installation. The Order Entry System serves two purposes: the first is the processing of customer's orders, printing of various documents, determination of raw material requirements and creation of an order history file; the second is the establishment of a computer record which becomes the main input to an on-line production control system.

Weckert, J. (2001). Computer Ethics - Why Bother?. In Proc. Selected papers from the 2nd Australian Institute of Computer Ethics Conference (AICE2000), Canberra, Weckert, J., Ed. ACS. Full Text.

The theme of the second conference of the Australian Institute of Computer Ethics (AiCE2000) was "Computer ethics, why bother?" Why bother indeed. Computers are already ubiquitous in Australia and there are no signs that they are becoming less important. We cannot stop this development even if we want to. And where there may be problems, politicians and lawyers draft laws to regulate behaviour. So what is the point of computer ethics?

Welsh, J., Rose, G. A. and Lloyd, M. (1986). An Adaptive Program Editor. Australian Computer Journal 18(2): 67-74.

A syntax-directed editor for the preparation of syntactically and static semantically correct programs is described. It differs from other editors described in the literature in that a pluralistic view of program structure is supported, which accommodates a number of development styles. Language and machine-independent aspects, such as efficient screen utilisation through adaptive formatting and detail suppression, incremental parsing and display, and minimal sequences to effect program changes are discussed.

Wesson, J. L. (2001). The Role of HCI Design Patterns in Software Development. Journal of Research and Practice in Information Technology 33(1): 42-53. First Page.

This paper discusses the role of HCI design patterns in software development. The concept of a design pattern, whilst popular in several other fields including architecture and software engineering, is relatively new to human-computer interaction (HCI). The potential of pattern languages as a vehicle for the dissemination of HCI design knowledge is becoming widely recognized within the HCI community. This potential is based on the ideas of the architect Christopher Alexander. Patterns are developed to record the invariant properties that exist in a design solution in order to resolve conflicting social, cognitive and technological forces. Patterns are interlinked into a network (termed a pattern language) to support different levels of user interface design.

Wesson, J. L. and Warren, P. R. (2001). Interactive Visualisation of Large Multivariate Datasets on the World-Wide Web. In Proc. Australian Symposium on Information Visualisation, (invis.au 2001), Sydney, Australia, Eades, P. and Pattison, T., Eds., ACS. Full Text.

While, L. and Mildenhall, G. (2002). An Implementation of Parallel Pattern-Matching via Concurrent Haskell. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Whiteley, A. M. and Jordan, E. (1990). Behavioural Aspects of Introducing Change in Information Systems. Australian Computer Journal 22(2): 59-68.

The predictable social consequences of introducing fundamental change to a computerised information system are discussed. Attention is drawn to the need for strategic planners to consider that employees are slower to change than senior managers. A case is described to illustrate the effects of introducing an Information Centre organisation without due consideration of the social environment. Change must be introduced with sensitivity to potential behaviour problems. The use of the Grounded Theory approach is proposed, to involve employees in the change process.

Whiten, W. J. (1972). The Use of Periodic Spline Functions for Regression and Smoothing. Australian Computer Journal 4(1): 31-34.

The techniques for regression and smoothing using natural cubic spline functions described by Whiten (1971) are extended to include periodic cubic spline functions. Periodic and near periodic functions with known period and non-periodic functions can be combined in a flexible manner for the analysis of data. Local control over the smoothness of each type of component functions is available. Estimates of the distribution of data points and local variances are calculated.

Whitesides, S. (1992). Algorithmic Issues in the Geometry of Planar Linkage Movement. Australian Computer Journal 24(2): 42-50.

A linkage is a collection of rigid rods that are fastened together at their endpoints, about which they may rotate freely. A chain of links is a simple example of such a linkage. This paper is an introduction to algorithmic and complexity issues in the placement and movement of planar chains and linkages. (The treatment is entirely geometric; dynamics of linkages are not considered.)

Whitten, W. J. (1971). The Use of Multi-Dimensional Cubic Spline Functions for Regression and Smoothing. Australian Computer Journal 3(2): 81-88.

Methods of analysing multi-dimensional data using cubic spline functions are described. They are particularly suited to data with relatively few variables but containing more detail than can be readily extracted by multiple regression. Restraints on the amount of detail replace assumptions on the analytic form of the regression equation. The values calculated from the spline regression may be used as an abstraction of the data to indicate an analytic form or a simpler functional form. The methods described provide an indication of where data are sparse or absent and also calculate a local variance. Examples provide a comparison with multiple regression analysis.

Whymark, G. K. (1991). Development of the EIS Concept and its Implementation in the RAN. Australian Computer Journal 23(3): 110-118.

Executive Information Systems (EIS) and Executive Support Systems (ESS) are a form of decision support system (DSS) for senior executives. This paper presents an overview of the EIS concept and its implementation in the Royal Australian Navy. The terms EIS and ESS are defined, and their relationship to other forms of decision support are discussed in terms of their purpose and function. The difference between management functions dealing with operational and tactical issues and those dealing with strategic issues are also addressed as these concepts are fundamental to the development of user oriented decision support systems. The development of the EIS concept as it would apply to a particular organisation is discussed and the methodology, pitfalls and successful strategies are described. The RAN has implemented an EIS and this report briefly discusses the development and implementation of an EIS drawing on that experience. Finally, the value of an EIS will be addressed, some observations will be made on the future of EIS and DSS and recommendations put forward as to what research could provide useful results.

Wiebe, A. (1990). Intellectual Property Protection of User Interfaces in USA and Germany. Australian Computer Journal 22(4): 133-139.

Emerging as one of the most important issues in intellectual property law is protection of user interfaces. The leading economic position of the US in the software market is reflected by its forming the issues in the legal classification of this new technology. A comparative study reveals the impact of the American legal development on German law as being that many emerging principles of law in this field can be availed of in a civil law country as well. In copyright law, this concerns the dichotomy of idea and expression and the classification of various elements of the user interface accordingly, regarding the user interface as a work separate from the program code. The same is true for the identification of unprotectable functional elements of the user interface. Copyright protection may be supplemented by other intellectual property schemes, like patent law. The scope of protection provided for user interfaces accordingly will have a major impact on the economic development in this software field, including considerations of standardizations and compatibility. Policy consideration suggest a rather limited scope of protection.

Wigley, G. and Kearney, D. (2002). The Management of Applications for Reconfigurable Computing using an Operating System. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Wijegunaratne, I., Socic, M. and Chow, B. (1994). An Architecture for Client/Server Application Software. Australian Computer Journal 26(2): 30-41.

A considerable amount of interest has developed over the last few years in client/server computing and its applicability to commercial applications. However, most of the published discussion has been confined to the technical infrastructure - or alternative inferstructures - upon which one can implement client/server software. Very little has been said about the wider aspects of developing systems and software given a client/server technical infrastructure. This paper is an attempt to address these application software issues. Specifically a model for the structure of application software in a client/server environment is proposed, covering areas such as the organisation and scope of client and server software components.

Wilcke, W. W. (2002). Computer Architecture Challenges in the Next Ten Years. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS.

Wildman, L. (2002). Requirements Reformulation using Formal Specification: A Case Study. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Williams, G. J. (1987). Some Experiments in Decision Tree Induction. Australian Computer Journal 19(2): 84-91.

This paper presents a number of experiments dealing with various aspects of the ID3 decision tree induction algorithm. The aspects dealt with include the choice of attribute to split on, exception split pruning, and combining decision trees.

Williams, G. J. (1989). FrameUP: A Frames Formalism for Expert Systems. Australian Computer Journal 21(1): 33-40.

This paper presents an introduction to frames-based representation schemes for use in the construction of rule-based expert systems. The features that are relevant to such expert systems are discussed, followed by an example of the type of rule application mechanism that the system implements. Advantages of such a system are presented.

Williams, T. and Parsons, R. (2001). Practical Experience Using a Computational Model for the Design of Heterogeneous Distributed Software. Journal of Research and Practice in Information Technology 33(2): 146-157. First Page.

Heterogeneous cluster environments are becoming an increasing popular platform for executing parallel applications. Efficient heterogeneous programs must account for the differences inherent in such an environment. We propose the HBSP model of computation as a framework for developing applications for heterogeneous clusters of workstations. The utility of the model is demonstrated through the design and analysis of the scatter and one-to-all broadcast algorithms. Extensive experimentation illustrates the benefits of using the model for heterogeneous program development. By hiding the non-uniformity of the underlying system,the HBSP model provides a framework that embraces the heterogeneity of the underlying system.

Williams, W. T. (1980). TWONET: A New Program for the Computation of a Two-Neighbour Network. Australian Computer Journal 12(2): 70.

A network based of the first two nearest neighbours produces "network-groups" comparable with classificatory groups, but with an overt internal network structure. The procedure has proves powerful in a number of biological applications, but the program originally used had several shortcomings. An improved program TWONET, faster and with a more informative output, is now available on the TAXON library of the CSIRO Cyber 76 computer in Canberra.

Williams, W. T. and Lance, G. N. (1975). POLYDIV: A Divisive Classificatory Program for All-Numeric Data. Australian Computer Journal 7(3): 144.

Wilson, W. H., Burrows, C. F. and Sidhom, M. (1982). Design of an Interactive Financial Planning Package. Australian Computer Journal 14(1): 26-31.

This paper describes features of the design of an interactive financial planning system for financial planning professionals. The system consists of a modelling language, with translator and code interpreter, facilities for generating reports, for creating and editing financial models, and file-handling functions. As the modelling language is designed to enable financial planners to describe models in familiar terms, it is non-procedural, and supports financially oriented built-in functions. File-handling functions allow users to avoid complicated interactions with an operating system. Users can investigate the effects of "what-if"-type changes to a model. Informal descriptions of the syntax adopted for the MODELER package, (developed at the University of Sydney Computing Centre), are included.

Windross, A. J. (1981). Introduction of a Statewide Computerised Network. Australian Computer Journal 13(2): 42-45.

This paper examines the planning for a New South Wales State-wide computerised communications network and its implementation. The network is used for the support of more than 2000 cash selling ticket terminals. Particular emphasis is paid to the network outside the Sydney metropolis. The substantial implementation problems encountered are described and their solution outlined.

Winter, K. (2002). Model Checking Railway Interlocking Systems. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Wise, M. J. (1989). An Implementation of Modules in Prolog. Australian Computer Journal 21(4): 141-150.

One obvious shortcoming in many Prolog implementations has been the lack of facilities for modularizing large Prolog programs, for providing information hiding, and generally for managing the space of user-defined names; predicates and operators are visible across the entire program in which they are used. One solution is to introduce "traditional" modules into Prolog, which is to say the sort of modules, familiar to users of Modula 2 (except with a Prolog flavour). The paper describes a set of predicates which implement "traditional" modules in UNSW-Prolog. The implementation is arguably the most comprehensive to date, and includes the ability to define nested, parameterized modules. Within a module predicates can be defined by clauses local to that module and by imports from any number of other modules. Finally, an extension to facilitate Simula-style classes is provided.

Witt, R. J. and Tyerman, S. P. (2002). Reducing Cognitive Overhead on the World Wide Web. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Wolfendale, G. L. (1980). The CSIRONET Local Computer Network. Australian Computer Journal 12(3): 86-88.

This paper describes work carried out to integrate hosts into a resource sharing network via a high speed bus, Network systems Corp's (NSC) HYPERchannel, involving protocol and software development. This latter is referred to as the local network.

Wong, G., Kong, A. and Ngai, S. (1990). A Study of Unauthorised Software Copying Among Post-Secondary Students in Hong Kong. Australian Computer Journal 22(4): 114-122.

This study investigates software copying among post-secondary students in Hong Kong. Over 500 students were surveyed in 1989. The magnitude of the problem in Hong Kong is quantified. Using factor analysis and regression analysis, several factors that significantly affect three variables (use of copied software; allowing others to copy software and purchase of illegal software) are identified. Implications of the findings, and recommendations on how to control the problem are presented.

Wong, K.-P., Feng, D., Meikle, S. R. and Fulham, M. J. (2001). Functional Segmentation of Dynamic Emission Tomographic images. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Wong, K.-P., Feng, D., Meikle, S. R. and Fulham, M. J. (2001). Non-Invasive estimation of Cerebral Metabolic Rate of Glucose Using Simultaneous Estimation and Cluster Analysis: A feasibility Study. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Wong, K.-P., Meikle, S. R., Feng, D. D. and Fulham, M. J. (2002). Numerical Deconvolution by a Monte Carlo Approach with Application to Dynamic Cardiac Perfusion Tc-99m SPECT. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Woo, J., Woo, J., Attali, I., Caromel, D., Gaudiot, J.-L. and Wendelborn, A. L. (2002). Alias Analysis for Exceptions in Java. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Wood-Harper, A. T., Corder, S., Byrne, B. and Hughes, J. (1999). Ethically Situated Information Systems Development. Australian Computer Journal 31(3): 66-71.

An understanding of a problem situation is typically described as the starting point for the information system development process. Methodologies differ in the perspective used to view the situation. Technically orientated methodologies tend to view the organization metaphorically as a machine that can be fixed through the application of tools. Organizationally orientated methodologies work to expose and reveal the cultural, political, and social dimensions, recognisizing in new implementations of information systems (IS) a potent change factor in these human dimensions can be obtained by analyzing the ethical perspectives of the actors in the situation and the ethical dilemas faced by the actors, defined in this case to include the analysis (or analysis team) as well.

Woodhouse, D. (1983). Student Selection for Computing Courses. Australian Computer Journal 15(1): 33-37.

This article refers to the diploma in Computer Science at La Trobe University. This course is open to graduates of other disciplines, and so it was difficult to determine appropriate criteria for selecting from the large number of applicants. Over a four year period, a number of tests were administered to students selected for the course, and the results correlated with performance in the course. Significant positive correlations with the results of the Computer Aptitude Battery have been obtained. This test is now being used as a major selection mechanism for the course.

Woodings, T. (1987). The Professional Development and Continuing Education of Computing Practitioners. Australian Computer Journal 19(4): 224-230.

The need for an adequate continuing-education programme is considered from the points of view of professional standards, career motivation and the requirements of the computing industry. Consideration is also given to methods of course presentation. Four areas of high priority are identified.

Wu, Q., He, X. and Hintz, T. (2002). Image Segmentation on Spiral Architecture. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Xiao, Y. and Yan, H. (2002). Facial Feature Location with Delaunay Triangulation/Voronoi Diagram Calculation. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Xiong, C., Murata, T. and Tsai, J. (2002). Modelling and Simulation of Routing Protocol for Mobile Ad Hoc Networks Using Coloured Petri Nets. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

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The structures of a number of class libraries available commercially at a snapshot in time (in 1992) have been evaluated in terms of their semantic cohesiveness. This evaluation is undertaken in terms of the degree to which the libraries use specialisation or specification inheritance and in terms of the way specific classes are placed in the abstraction hierarchy. We highlight areas where further inter-library rationalisation would be welcomed by the user community.

Yasrebi, M. (1992). A Review of Various Philosophies on the Design and Analysis of Parallel Computer Architectures for Vision. Australian Computer Journal 24(4): 139-151.

Parallel computer vision is a key element in many applications, where intelligent devices are needed. Several classes of synthesised and proposed vision-oriented parallel computer architectures are reviewed. Key design principles and methodologies of these representative and state-of-the-art systems are used to identify and classify various properties of such systems. We will show how a study of the philosophies used in the designs of various systems can result in a classification of such parallel computers. These results are then used to outline and analyse some specific challenges and trade-offs that must be considered in the design and analysis of vision oriented parallel computing.

Yohe, J. M. (1978). An Overview of Programming Practices. Australian Computer Journal 10(2): 61-74.

The purpose of this paper is to indicate something of the nature of "good programming". In this context, programming is taken to mean the entire process of communication between humans and computers. The programming process is sub-divided into nine tasks, and an elementary discussion of each of these tasks is presented. Although the paper is primarily directed to the student or novice programmer, more experienced people may find it a worthwhile aid in codifying or reinforcing their experience.

Yoshida, Y., Aritsugi, M. and Kanamori, Y. (2002). Performance Evaluation of Combining Data Migration and Method Migration in Object Database Environments. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Yu, X., Hoang, D. B. and Feng, D. D. (2001). A Simulation Study of Using ER Feedback Control to Transport Compressed Video over ATM Networks. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Yuen, C. (2001). Strong and Weak Memory Consistencies. Journal of Research and Practice in Information Technology 33(4): 321-324. First Page.

Zaiane, O. and Antonie, M.-L. (2002). Classifying Text Documents by Associating Terms With Text Categories. In Proc. Thirteenth Australasian Database Conference (ADC2002), Melbourne, Australia, Zhou, X., Ed. ACS. Full Text.

Zaslavsky, A. and Tari, Z. (1998). Mobile Computing: Overview and Current Status. Australian Computer Journal 30(2): 42-52.

In recent years, mobile computing has become the focus of vigorous research efforts in various areas of computer science and engineering. These areas include wireless networking, distributed systems, operating systems, distributed databases, software engineering, applications development, just to name a few. This paper introduces the conceptual overview of mobile computing, its achievements, challenges and opportunities. The current status and ongoing research projects in mobile computing worldwide are detailed. This paper also discusses the two Australian workshops on mobile computing, databases and applications held in 1996 and 1997.

Zatorski, R. J. (1970). Picture-Language Interaction in Artificial Intelligence. Australian Computer Journal 2(4): 173-179.

The paper outlines a proposed application of the model designed by Clowes (1970) for the recovery of the structure of solid polyhedra from their representations in two-dimensional graphs to the recovery of structures underlying scenes represented in natural language. The recovery of the latter is an essential step in artificial intelligence systems requiring interaction between pictures and language.

Zelinsky, A. (1988). Robot Navigation with Learning. Australian Computer Journal 20(2): 85-93.

Navigation is the most important function of an autonomous mobile robot. Research into mobile robot navigation has concentrated on the problem of finding optimal paths through known environments. In such cases the robot will need to learn and understand the environment. This paper will present an algorithm for learning in an unknown environment with a mobile robot. The robot will learn the environment by sensing while it is executing paths, which have been generated by a path planner. As obstacles are encountered en route to a goal, the model of the environment is updated and a new path to the goal is planned to avoid the obstacles. The paths generated by this system will be initially locally optimal, but as knowledge of the environment increases the optimality of the paths generated will improve until eventually global optimality is attained. The learning algorithm presented in this paper makes use of quadtree representation to model the environment and uses the distance transform methodology to generate paths of navigation for the robot.

Zeng, Z. and Yan, H. (2001). Region Matching by Optimal Fuzzy Dissimilarity. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Zeng, Z. and Yan, H. (2002). Hidden Line Removal for 2D Cartoon Images. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Zhang, K. and Zhang, D.-Q. (1998). Instrumenting Parallel Programs for Performance Visualisation. Australian Computer Journal 30(1): 30-38.

Program visualisation and execution animation are usually achieved by instrumenting the original program with event collecting code. To maintain the original program behaviour, the effect of instrumentation should be kept at a minimum. In other words, the instrumentation overhead introduced into the program should be as low as possible. This paper presents some instrumentation methods to support a visualisation tool that assists the development of message-passing parallel programs. It discusses these instrumentation methods for event collection, and reports the preliminary evaluation results of the approaches implemented in Occam2 on a multi-transputer system.

Zhang, K.-B., Zhang, K. and Orgun, M. A. (2002). Using Graph Grammer to Implement Global Layout for a Visual Programming Language Generation System. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Zhang, L., Kristensen, L. M., Janczura, C., Gallasch, G. and Billington, J. (2002). A Coloured Petri Net based Tool for Course of Action Development and Analysis. In Proc. Formal Methods in Software Engineering and Defence Systems 2002, Adelaide, Australia, Lakos, C., Esser, R., Kristensen, L. M. and Billington, J., Eds., ACS. Full Text.

Zhang, Q., Huang, K. and Yan, H. (2002). Fingerprint Classification Based on Extraction and Analysis of Singularities and Pseudoridges. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.

Zhang, Z. (2000). Constructing Conjunctive Attributes using Production Rules. Journal of Research and Practice in Information Technology 32(1): 13-38. First Page.

Many existing constructive decision tree learning applications such as Fringe and Citre construct conjunctions or disjunctions directly from paths of decision trees. This paper investigates a novel attribute construction method for decision tree learning. It creates conjunctions from production rules that are transformed from decision trees. Irrelevant and unimportant conditions are eliminated when paths are transformed into production rules. Therefore, this new method is likely to construct new attributes with relevant conditions. Three constructive induction algorithms based on this basic idea are described and are empirically evaluated by comparing with C4.5 and a Fringe-like algorithm in a set of artificial and natural domains. The experimental results reveal that constructing conjunctions using production rules can significantly improve the performance of decision tree learning in the majority of the domains tested in terms of both higher prediction accuracy and lower theory complexity. These results suggest an advantage of the attribute construction method that uses production rules over the method of constructing bew attributes directly from the paths in noisy domains.

Zhao, L. and Coplien, J. O. (2002). Symmetry in Class and Type Hierarchy. In Proc. Fortieth International Conference on Technology of Object-Oriented Languages and Systems (TOOLS Pacific 2002), Sydney, Australia, Noble, J. and Potter, J., Eds., ACS. Full Text.

Zheng, L. and Stuckey, P. J. (2002). Improving SAT Using 2SAT. In Proc. Twenty-Fifth Australasian Computer Science Conference (ACSC2002), Melbourne, Australia, Oudshoorn, M. J., Ed. ACS. Full Text.

Zhong, D. (2001). Color Space Analysis in Color Image Segmentation. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS.

Zhou, X. D., Zaslavsky, A., Rasheed, A. and Price, R. (1998). Efficient Object-Oriented Query Optimisation in Mobile Computing Environment. Australian Computer Journal 30(2): 65-76.

Convergence of object-oriented technologies with advances in computer and communications technologies will lead to new paradigms and approaches to building object-based distributed systems, including mobile computing systems. Portable and mobile computers involved in mobile database query processing use battery power. These mobile hosts have severe battery energy problems and significant improvements in battery technology are not yet forthcoming. Portable computers run on different energy consumption modes (normal and doze). This feature is used to save battery energy through flexible and efficient query optimisation. This paper discusses and proposes a two-dimensional energy-work query optimisation algorithm. The algorithm employs dynamic programming techniques and achieves a balance between saving energy consumption at mobile hosts and minimising total work for query processing in the whole database. A simulation of the algorithm is implemented and analysed.

Zhu, Y. and Wong, W. F. (2002). Sensitivity Analysis of a Superscalar Processor Model. In Proc. Seventh Asia-Pacific Computer Systems Architectures Conference (ACSAC2002), Melbourne, Australia, Lai, F. and Morris, J., Eds., ACS. Full Text.

Zobel, J. and Dart, P. (2000). Partitioning Number Sequences into Optimal Subsequences. Journal of Research and Practice in Information Technology 32(2): 121-129. First Page.

We consider how to partition finite sequences of positive numbers into subsequences such that each resulting subsequence has a sum of at least a given minimum. Given several different optimality criteria, based on maximising the number of subsequences and minimising their variance in size, we develop and analyse a series of algorithms that yield optimal solutions. Key Words: algorithms, analysis of algorithms, computational complexity.

Zou, J. J. and Yan, H. (2001). Vectorization of Cartoon Drawings. In Proc. Selected papers from Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Eades, P. and Jin, J., Eds., ACS. Full Text.

Zou, J. J. and Yan, H. (2002). Reduction of Artifacts in Cosine Transform Coded Images. In Proc. Selected papers from 2001 Pan-Sydney Workshop on Visual Information Processing, Sydney, Australia, Feng, D. D., Jin, J., Eades, P. and Yan, H., Eds., ACS. Full Text.