Ph. D.

A "causal" expert system based on hypothetical reasoning and its application to a Mark 45 turret gun's lower hoist are described. HOIST is a system that performs fault diagnosis without the use of a domain expert or "shallow rules". Rather its "knowledge" is coded directly from a structural specification of the Mark 45 lower hoist. The technology reported here for assisting the lesser acquainted diagnostician differs considerably from the normal rule-based expert system techniques: it reasons about machine failures from a functional model of the device. In a mechanism like the lower hoist, a functional model must reason about forces, fluid pressures and mechanical linkages, that is, qualitative physics. HOIST technology can be directly applied to any exactly specified device for modeling and diagnosis of single or multiple faults. Hypothetical reasoning, the process embodied in HOIST, has general utility in qualitative physics and reason maintenance. / Master of Science

Computer systems for the interpretation of diagnostic ECGs are widely used, but currently provide no explanatory or teaching functions of value to the less experienced practitioner. The relevant literature is reviewed, and specifications are provided for an ECG analysis system which will function as a learning aid for undergraduate and postgraduate medical students. Key aspects of the specifications are implemented on an IBM-PC. Recommendations for further development are provided.

No description available.

Parkinson's Disease can be treated by a micro-electrode guided neurosurgery called a Pallidotomy or Deep Brain Stimulus. A new software program, called Onetrack, is being developed and incorporates a three dimensional virtual model of the brain, a advanced digital signal processor and a knowledge based system (KBS). This thesis discusses the design and development of this KBS. The purpose of the KBS is to assist the surgical team in identifying the different anatomical structures and neuronal cell types of the brain. Therefore, improving the efficiency of the procedure.

Call number: LD2668 .T4 1986 C68 / Master of Science

This thesis is concerned with the applicability of model reference adaptive control to the control of robot manipulators under a wide range of configuration and payload changes, and a comparison of the performance of this technique with that of the non-adaptive schemes. The dynamic equations of robot manipulators are highly nonlinear and are difficult to determine precisely. For these reasons there is an interest in applying adaptive control techniques to robot manipulators. In this work, the detailed performance of three adaptive controllers are studied and compared with that of a non-adaptive controller, namely, the computed torque control scheme. Computer simulation results show that the use of adaptive control improves the performance of the manipulator despite changes in the payload or in the manipulator configuration. Making use of these results, a rule-based controller is developed by dividing a given manipulation task into portions where a particular adaptive control scheme, based on a specific linearized subsystem model, performs best. This strategy of selecting the proper controller during each portion of the overall task yields a performance having the least deviation from the desired trajectory during the entire length of the task.

Research report presented to SBL, Unisa, Midrand. / No abstract / Graduate School of Business Leadership / MBL

published_or_final_version / Urban Planning / Master / Master of Science in Urban Planning

published_or_final_version / abstract / Computer Science / Master / Master of Philosophy