Development of computer software support for interpretive structural modelling

Includes bibliographical references.Interpretive Structural Modelling is a computer-driven method for dealing with complexity, by allowing individuals or groups to interpret the inter-relationships between different aspects or elements of a problem. In doing this interpretation, the elements are structured, and from this structuring, a graphical model is produced, allowing the modeller(s) to better understand the problem. The main contribution of this thesis was to develop a computer package for Interpretive Structural Modelling (ISM), for use at the School of Engineering Management at the University of Cape Town. The package was developed for the IBM PC

A Specification of the Soar Cognitive Architecture in Z

A formal specification of the sixth revision of the Soar architecture in the Z notation was constructed to elucidate and clarify the definition of Soar and to guide its implementation. Soar is a cognitive architecture that has been successfully applied to many domains and has been proposed as an exemplar unified theory of cognition. Z is a model theoretic specification language based in set theory that has syntax and type checking programs available. The specification has a complete coverage of the architecture, a low level of abstraction and a considerable implementation bias

Measuring concurrency in CCS

A research report submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of ScienceThis research report investigates the application of Charron-Bost's measure of currency m to Milner's Calculus of Communicating Systems (CCS). The aim of this is twofold: first to evaluate the measure m in terms of criteria gathered from the literature: and second to determine the feasiblllty of measuring concurrency in CCS and hence provide a new tool for understanding concurrency using CCS. The approach taken is to identify the differences hetween the message-passing formalism in which the measure m is defined, and CCS and to modify this formalism to-enable the mapping of CCS agents to it. A software tool, the Concurrency Measurement Tool, is developed to permit experimentation with chosen CCS agents. These experiments show that the measure m, although intuitively appealing, is defined by an algebraic expression that is ill-behaved. A new measure is defined and it is shown that it matches the evaluation criteria better than m, although it is still not ideal. This work demonstrates that it is feasible to measure concurrency in CCS and that a methodology has been developed for evaluating concurrency measures.Andrew Chakane 201

Towards extracting non-strict independent and-parallelism using sharing and freeness information

Logic programming systems which exploit and-parallelism among non-deterministic goals rely on notions of independence among those goals in order to ensure certain efficiency properties. "Non-strict" independence (NSI) is a more relaxed notion than the traditional notion of "strict" independence (SI) which still ensures the relevant efficiency properties and can allow considerable more parallelism than SI. However, all compilation technology developed to date has been based on SI, presumably because of the intrinsic complexity of exploiting NSI. This is related to the fact that NSI cannot be determined "a priori" as SI. This paper fills this gap by developing a technique for compile-time detection and annotation of NSI. It also proposes algorithms for combined compile- time/run-time detection, presenting novel run-time checks for this type of parallelism. Also, a transformation procedure to eliminate shared variables among parallel goals is presented, attempting to perform as much work as possible at compiletime. The approach is based on the knowledge of certain properties about run-time instantiations of program variables —sharing and freeness— for which compile-time technology is available, with new approaches being currently proposed