Thesis (M. Sc.)--Carleton University, 2001. / Includes bibliographical references (p. 111-116). Also available in electronic format on the Internet.

Thesis (M.S.)--Ohio University, August, 1992. / Title from PDF t.p.

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 121-124).

Thesis (M. Phil.)--University of Hong Kong, 1990.

The applicative or functional language SASL is investigated from the point of view of an implementation. The aim is to determine and experiment with a run-time environment (SASL parallel machine) which incorporates parallelism so that constituent parts of a program (its sub-expressions) can be processed concurrently. The introduction of parallelism is characterised by two fundamental issues. The type of programs, referred to as parallel and the so called strategy of parallelism, employed by the parallel machine. The former concerns deriving a graph from the program text indicating the order in which things must be done and the notion of "worthwhile" parallelism. In order to obtain a parallel program the original (sequential) program is transformed and/or modified. Certain programs are found to be essentially sequential. Parallelism is expressed as call-by-parallel parameter passing mechanism and by a parallel conditional operator, suggesting speculative parallelism. The issue of the strategy of parallelism concerns the scheme under which a regime of SASL processors combine their effort in processing a parallel program. The objective being to shorten the length of computation carried out by the sequential machine on the initial program. The class of parallel programs seems to be non-trivial and it includes both non-numerical and numerical programs. The "speed-up" by appealing to parallelism for such programs is found to be substantial.

Civil engineers are increasingly called upon to design according to codes of practice which are foreign, or otherwise unfamiliar to the engineer. Some form of 'tool' to aid such engineers in the safe and effective use of unfamiliar codes, is therefore highly desirable. The argument presented in this thesis, is that a specialised 'knowledge-based system' (KBS) can be successfully constructed in order to provide various sons of insights into the design methods used in certain codes of practice. Three key ideas were used in the implementation produced during the research: the development of a novel set of complementary 'facilities' for examining the design methods used in codes; the support of comparison between the examination of two different codes; and ensuring the system's representation of codes and their examination, could be made readily comprehensible to engineers by using familiar human language phrases. Seven different facilities were developed in the research, including: the ability to view the codes installed in the system in a form close to a human language (such as English or French); the ability to perform parts of a code-based design procedure to various levels of detail; and the ability to inspect the interdependences of design parameters within codes. Use of these symbolic and numerical methods could provide the engineer with the information required to understand how and why an unfamiliar code would specify surprising, or otherwise unusual design parameters in some particular situation. They could also be used in a more exploratory fashion, with t1ie same broad aim of greater understanding of an unfamiliar code. A KBS is a sophisticated computer program that uses the idea of processiilg knowledge information. A characteristic feature of KBSs is that one of their primary components is a 'knowledge base' - a store of human expertise. The KBS built in this research, 'COPES' used an existing abbreviated form of the reinforced concrete (RC) beam design codes as its knowledge base. In particular, it contained 'procedural knowledge'. COPES was implemented using conventional computer systems and progranuning languages (pascal and FORTRAN on a Sun workstation). This is in contrast to most contemporary KBSs, which are often built using a 'shell', or an unconventional declarative programming language such as Prolog. One reason for this choice was that COPES used parts of previous computing work done with RC beam design codes, that had also used conventional computing techniques. However, our research did cover an investigation into the prospects for an alternative approach using a modem expert system shell. (It was confirmed that such an approach was generally less suitable in this particular application.) The COPES system proved to be a useful prototype 'toolbox' of various procedural knowledge extraction operations, which could help an engineer's understanding of an unfamiliar code of practice. To provide a practical system, the various explanatory methods developed could potentially be incorporated into an overall CAD (Computer-Aided Design) environment, or alternatively, wrapped up in a more sophisticated interactive program.

An arbitrary continuous system model can be constructed on a Graphic Display by interacting with a light pen and dials. The user is presented with a control language and a menu on the Graphic Display, which uses pre-defined symbols to design a Continuous System Model. After constructing the model he wants to simulate, the user can assign appropriate variable names and values to the symbols, direct flow of information or material between components, can assign mathematical relationships between the components of a model, and can sketch graphical functions (x-y relationships) on the Graphic Display with the help of cross-hairs. The model, when built, can be saved on disk. In order to make modifications to the model at later time, a previously saved model can be restored. Changes such as altering values, mathematical relationships, and the deletion or addition cf components can be made before rerunning a simulation. Once the user is satisfied with the model description phase and when his model is complete, a CSBP program for that model is written onto disk, which can then be compiled and run in order to obtain the results for the specified variables in tabulated form. As visual aids, plots against Time can also be observed on the Graphic Display or can be plotted cn an X-Y plotter. The CAB system presented here provides an interactive tool for the design, modification and experimentation with Continuous System Models. As such it can enhance the modeller's representation and understanding of reality. / Science, Faculty of / Computer Science, Department of / Graduate

In this thesis, a program, HOUSE, is described that can interpret line sketches of houses and other polyhedral objects. The program is part of the SEE project, a sketch understanding project at the University of British Columbia. In this respect HOUSE is a generalization of MAPSEE, a program that can interpret line sketches of geographic maps. The most important goal of HOUSE is to test the adequacy and efficiency of the program's control structure which is based on a helical metaphor for the perceptual process. Such a helical metaphor is based on a stratified interpretation process with a bottom-up, pass-oriented control structure. HOUSE takes (like MAPSEE) as input a plot program by means of which the sketch can be displayed on a graphical display device. The program subsequently describes the sketch at different levels of representation. These levels can be categorized in two domains: a picture domain consisting of two-dimensional representations of the sketch and a scene domain consisting of three-dimensional representations. Processing in the picture domain is dominated by a segmentation process that results in three different types of representations. In contrast with MAPSEE, HOUSE also maintains different levels of representation in the scene domain. Each of these levels represents the sketch at a different degree of abstraction. The cycle of perception with its four stages serves as a metaphor for describing the interpretation process at each of these levels. Cues are first formed by the segmentation process (cue discovery); these cues (the vertices) suggest possible interpretations for the primitives (the edges) at the lowest level in the interpretation domain (model invocation); these interpretations are taken by a network consistency algorithm that tests the global consistency among these interpretations (model testing and elaboration). Interpretations that are part of a globally consistent description of the sketch then serve as cues for the next higher level where the cycle is repeated. This process continues until the sketch is described at the highest possible level of abstraction. Several examples were run with the program. Apart from a number of desirable features, these tests showed two important weaknesses of the helical metaphor: its inability to account for incomplete line sketches, and its inability to impose top-down constraints. These weaknesses led to the formulation of a more powerful metaphor: the multi-helix. Among other things, this multi-helix allows multiple access to the different levels of representation in both a bottom-up and top-down direction. A comparison of the multi-helix metaphor with several other perceptual processing metaphors argues for the former's superior ability to account for certain characteristics of the perceptual process. Consequently, the multi-helix can be seen as another step towards a theory of machine perception. / Science, Faculty of / Computer Science, Department of / Graduate

This thesis describes the design of a well mapped machine¹ for the language BCPL. Based on a generalized notion of stack machines the SLIM (Stack Language for Intermediate Machines) machine is described. As the acronym suggests, representation of BCPL programs in SLIM is in fact slim compared with other architectures. The utility of this measure for comparison with other architectures is discussed and some encouraging results presented. Apart from this result, some advance is made in the classical mode of porting BCPL programs. Normally the compiler produces OCODE from which INTCODE is generated. The BCPL SLIM compiler shortcuts this process by generating SLIM directly from the program tree thus dispensing with software corresponding to the OCODE to INTCODE translator. Translation of BCPL programs is thus simplified and speeded up. ¹by well mapped we mean that transformations in the high level language correspond closely to those in the low level machine representation. / Science, Faculty of / Computer Science, Department of / Graduate