Abstracts:

Jasna Kuljis
Department of Applied Technology and Computing, Roehampton Institute London, West Hill, London SW15 3SN, England; jkuljis@roehampton.ac.uk

Computer-based simulation modelling is one of the domains that is particularly demanding in terms of user interfaces. It is also an area that often pioneers new technologies that are not necessarily previously researched in terms of human-computer interaction (HCI). Issues that influence the `usability' of such systems are examined. Several representative systems were investigated in order to generate some general assumptions with respect to those characteristics of user interfaces employed in simulation systems. There is need for simulation systems that can support the developments of simulation models in many domains, which are not supported by contemporary simulation software. Many user interface deficiencies are discovered and reported. On the basis of findings in this research, proposals are made on how user interfaces for simulation systems can be enhanced to match better the needs specific to the domain of simulation modelling, and on how better to support users in simulation model developments. (pp. 587-598)

Keywords:simulation, HCI

Mike Pidd
Department of Management Science, The Management School, Lancaster University, Lancaster LA1 4YX, England; m.pidd@lancaster.ac.uk

Much of the progress within discrete simulation has gone hand-in-hand with general developments in computing. Recent years have seen software developers putting great efforts into improving the user interfaces of discrete simulation systems. This too parallels developments elsewhere. This paper considers what further benefits there might be for users and developers of simulation software from more careful attention to interface design. (pp. 599-605)

Keywords:simulation, HCI

Brian Lehaney
Faculty of Business, University of Luton, Park Square, Luton, Beds, LU1 3JU, England

Simulation is both popular and powerful, but reportage of simulation case studies indicates that in many cases process is treated cursorily, and end-user-acceptance of final models is not forthcoming. Whilst texts often proclaim the importance of process, this is usually left to the discretion of the modeller. A range of problem structuring (or soft) methodologies have been developed to address process issues. However, these can be both slow and unwieldy. This paper outlines a case which utilises the principles of soft methodologies in a relatively quick and dirty approach to process. (pp. 607-612)

Keywords:simulation, soft systems methodology, health care systems

George M. Giaglis
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England; george.giaglis@brunel.ac.uk
Ray J. Paul
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England ray.paul@brunel.ac.uk
Georgios I. Doukidis
Department of Informatics, Athens University of Economics and Business, Patission 76, Athens 104 34, Greece

Business process modelling (BPM) is an increasingly emerging field of simulation application. Although it has been practically demonstrated that simulation can be an effective tool for business redesign, there does not exist a comprehensive framework to explain the characteristics of business processes and identify specific requirements for their modelling. Furthermore, hardly any attention has been paid to the modelling of inter-organisational business systems. In this paper, we examine the nature of business processes in the light of modern change management approaches and propose a set of requirements for their modelling. We then concentrate on inter-organisational processes and argue that modelling problems can be much more difficult to overcome when more than one business is involved, mainly due to the multiplicity of decision making levels involved and the subsequent need for multi-level output analysis. Based on an empirical study, we illustrate the practical problems of modelling inter-organisational business systems and suggest desirable characteristics of simulation packages for that purpose. (pp. 613-620)

Keywords:simulation, business process modelling

Robert M. Macredie
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England; robert.macredie@brunel.ac.uk
Simon J.E. Taylor
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England; simon.taylor@brunel.ac.uk
Richard Keeble
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England; richard.keeble@brunel.ac.uk
Xiaoning Yu
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England; cspgxxy@brunel.ac.uk

Virtual environments can be used as an effective tool for training and education. This paper cites many recent examples of such systems and divides current work into virtual environment development and the development of supporting technology for distributed access. A novel supporting technology for distribution is introduced. (pp. 621-626)

Keywords:simulation, virtual reality, distributed interactive simulation

Ingolf Stahl
Stockholm School of Economics, Box 6501, S-113 83 Stockholm, Sweden; iis@hhs.se

This paper informs about the development of the micro- GPSS system on the basis of feed-back from some 5000 students during a period of two decades, providing a stream-lined simulation system which within ten class room hours of teaching make students prepared to write fairly advanced simulation programs of practical interest. (pp. 627-635)

Keywords:simulation, education

Julika Siemer
Department of Information Systems, London School of Economics and Political Science, Houghton Street, London WC2A 2AE, England; j.siemer@ise.ac.uk

The demand for education in the area of simulation is in the increase. This paper describes how education in the field of simulation can take advantage of the virtues of intelligent tutoring with respect to enhancing the educational process. For this purpose, this paper gives an overview of what constitutes the objectives and the content of a comprehensive course in discrete event simulation. The architecture of an intelligent tutoring system is presented and it is discussed how these sophisticated learning aids offer individualised student guidance and support within a learning environment. The paper then introduces a prototype intelligent tutoring system, the simulation tutor, and suggests how the system might be developed to enhance education in simulation. (pp. 637-642)

Keywords:simulation, education, artificial intelligence

Tajudeen A. Atolagbe
Department of Information Systems and Computing, Brunel University, Uxbridge, UB8 3PH, England Tajudeen.Atolagbe@brunel.ac.uk

This paper describes architecture for an intelligent interactive instructional simulation modelling environment. It revolves around the production of tutorial and courseware authoring for different simulation software packages with a generic user interface shell. The generic shell is a ``front end'' which provides a uniform graphicaluser interface to diverse simulation modelling software tutorials. An object-oriented perspective is combined with tutorial activities based on the task classification structure to form the interactions between objects. The development environment brings together objects that are functionally coherent and allows them to share common resources within the shell. (pp. 643-650)

Keywords:simulation, education, artificial intelligence

Jadran Lenarcic
Jozef Stefan Institute, Jamova 39, 1111 Ljubljana, Slovenia; jadran.lenarcic@ijs.si
Bojan Nemec
Jozef Stefan Institute, Jamova 39, 1111 Ljubljana, Slovenia

To minimise a cost function in the secondary level of control of redundant manipulators, the gradient of the cost function is projected on the null space of the primary task. This projection, however, does not guarantee the maximum decrement of the cost function. In the present paper we rotate the null space of the primary task in order to find the maximum optimisation step. By this improvement, the optimisation procedure can provide the desired solution in much less iterations. (pp. 651-655)

Keywords:redundant manipulators, steepest descent optimisation, optimum step size

Raimund K. Ege
School of Computer Science, Florida International University, University Park, Miami, FL 33199; ege@cs.fiu.edu

Successful software today is built from components. Modern software engineering techniques, such as those based on the object paradigm, support the specification, implementation and re-use of components. Encapsulation is the term used to describe this basic knowledge representation principle of packaging information and its related functionality. This paper explores the concept of encapsulation as it is used in object-oriented programming languages, analysis and design methods, distributed systems and data bases. The paper uses a specification language - KAPSEL - that facilitates the specification of re-usable object-oriented software components to illustrate advanced encapsulation features. (pp. 657-664)

Keywords:software, object-orientation, encapsulation, programming languages

Robert Manger
Department of Mathematics, University of Zagreb, Bijenicka cesta 30, 10000 Zagreb, Croatia; manger@math.hr

This paper evaluates data compression capabilities of holographic neural networks. An outline of a possible ``holographic" compression method is given. Experiments are described, where the proposed method has been simulated on a series of data files. The obtained results are presented and discussed. Conditions are identified, which are necessary for proper functioning of the method. (pp. 665-673)

Keywords:artificial neural networks, holographic neural technology, data compression

Jeremy Horne
3128 West Reunion Drive, Phoenix, AZ 85027, USA; jhorne1@cris.com

Basic logic and math textbooks usually present a standards for prioritizing operators in parenthesis-free expressions. The authors say that it is a scheme dictated by convention, but not clear is a description of circumstances under which one would ever find ungrouped expressions and need to prioritize operators. This paper argues that the circumstances generating the expressions dictate the prioritization. That is, if logic and mathematics at a basic level represent the real world, then ordering the operators would have a ``natural'' foundation. Logic and mathematics reflect a structure of human consciousness, as suggested by Jean Piaget. The operators, themselves, have degrees of intellectual complexity and an empirical foundation with major philosophical import.
Section One describes logical aggregation and its importance. Section Two briefly examines three examples suggesting that the ease of logical thinking depends upon ordering of operators. Cases found in human learning theory and Boolean neural networks suggest that each operator has a unique level of complexity. In Section Three, the author proposes a method for finding a natural order of operators that more closely fits the way in which humans think, and Section Four advances a procedure to analyze seemingly unordered phenomena. Section Five describes the philosophy upon which this proposed research is predicated. Binary logic's syntax displays semantics of order in human consciousness, as biophysical and cosmological research indicate. The syntax, itself, may be semantic expressed by a deeper structure linked to that of the cosmos, itself. Section Six suggests a direction in which research should proceed to understand how the source of our being might be communicating to us. (pp. 675-682)

Keywords:consciousness, information, logic, operators, order, Piaget

Andrej Ule
Philosophical Department, Faculty of Arts, University of Ljubljana, Askerceva 2, 1000 Ljubljana, Slovenia

I wonder if is it possible to combine the view that consciousness is a flow of mental states with the view that it is not a process. I believe this combination is possible and necessary for a correct understanding and explanation of consciousness. I distinguish between a process (information-processing) and a non-process (at least not time-processed) side (aspect) of consciousness: The first consists of the neural information-process, the flow of sensations and the change of feelings. The second lies in the conception and representation of processing potentials of states of affairs, events and processes. The unity of process and non-process sides of consciousness lies in the awareness of time as an imaginary process that is the basis of all other processes. (pp.683-687)

Keywords:consciousness, processes, characteristic qualities, modality, potentiality, Wittgenstein, patterns, sensitivity, information