This dissertation is concerned with the representation of visual knowledge. Image features often have many different local interpretations. As a result, visual interpretations are often ambiguous and hypothetical. In many model-based vision systems the problem of representing ambiguous and hypothetical interpretations is not very specifically addressed. Generally, specialization hierarchies are used to suppress a potential explosion in local interpretations. Such a solution has problems, as many local interpretations cannot be represented by a single hierarchy. As well, ambiguous and hypothetical interpretations tend to be represented along more than one knowledge representation dimension limiting modularity in representation and control. In this dissertation a better solution is proposed. Classes of objects which have local features with similar appearance in the image are represented by discrimination graphs. Such graphs are directed and acyclic. Their leaves represent classes of elementary objects. All other nodes represent abstract (and sometimes unnatural) classes of objects, which intensionally represent the set of elementary object classes that descend from them. Rather than interpreting each image feature as an elementary object, we use the abstract class that represents the complete set of possible (elementary) objects. Following the principle of least commitment, the interpretation of each image feature is repeatedly forced into more restrictive classes as the context for the image feature is expanded, until the image no longer provides subclassification information. This approach is called discrimination vision, and it has several attractive features. First, hypothetical and ambiguous interpretations can be represented along one knowledge representation dimension. Second, the number of hypotheses represented for a single image feature can be kept small. Third, in an interpretation graph competing hypotheses can be represented in the domain of a single variable. This often eliminates the need for restructuring the graph when a hypothesis is invalidated. Fourth, the problem of resolving ambiguity can be treated as a constraint satisfaction problem which is a well researched problem in Computational Vision. Our system has been implemented as Mapsee-3, a program for interpreting sketch maps. A hierarchical arc consistency algorithm has been used to deal with the inherently hierarchical discrimination graphs. Experimental data show that, for the domain implemented, this algorithm is more efficient than standard arc consistency algorithms. / Science, Faculty of / Computer Science, Department of / Graduate

Discusses the development of a real-time finance management system (RFMS) computer application. RFMS lets users learn about and manage their personal finances and stock portfolio. Finances can be managed using management tools and calculators. The program uses a Java/XML based approach where real-time market data from different stock exchanges is fetched and displayed for the user. Stock performance can then be graphed.

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The problem of effective and efficient use of engineering software can be thought of as a Pareto optimal problem. However, the complexity of modern engineering software precludes the possibility of acquiring complete knowledge of the software's Pareto optimal set. Instead, heuristic knowledge must be acquired. The thesis proposes that heuristic knowledge be acquired via a knowledge acquisition procedure. The use of a knowledge acquisition system, which may be computerised, forms an integral part of this procedure. Two examples of knowledge acquisition illustrate the use of the knowledge acquisition procedure.

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Includes glossary. / Digitized by Kansas Correctional Industries

A new implementation of the calendar queue is described in this thesis. The calendar queue as previously implemented depended upon the use of multiple linked lists for the control of queue discipline. In the calendar heap implementation, the heap has been used to replace the previous functions of the linked list. Testing of the claim of O(1) execution time for the calendar queue was done. Comparisons of execution times of the calendar queue and the calendar heap have been made. Descriptions of the implementation as well as the complete C code for the calendar heap are included.

The design of a computerized system for the estimation of uranium potential supply in the United States constitutes the primary objective of this dissertation. Once completed, this system performs for various levels of economic variables, such as prices, the estimation of potential uranium supply without requiring the appraisal by geologists, area by area, of undiscovered uranium endowment. The main components that form the system are explicit models of endowment, exploration, and production. These component models are derived from engineering and geological data, and together, they comprise the system. This system is unique in that it links physical attributes of endowment to time series of price and production. This linkage is made by simulating the activities of the U.S. uranium industry, activities (exploration, mine development, and production) that are involved in the transformation of endowment to potential supply. Uranium endowment is first generated by employing a crustal abundance model; a data file containing characteristics (tonnage, grade, depth, intra-deposit grade variation) of the discrete deposits that comprise the endowment is established by this model. An exploration model relates discoveries to exploration effect and deposit characteristics. Discovery yield for a given effort is linked to the relative "discoverability" of the deposits of the endowment as well as to the total exploration effort. An economic evaluation is performed on each discovery to determine whether or not the deposit can be developed and produced, given the stated level of the economic variables. The system then determines the magnitude of potential supply that could be forthcoming from all discoverable and exploitable deposits for the stated economic circumstances. Initially, the parameters of the system must be estimated. The approach employed for this estimation makes use of the time series information on uranium exploration and production activities. In essence, the system is used to simulate the past history of the U.S. uranium industry (period 1948-1978) and to generate industry statistics for these activities; the parameters selected are those values that cause the system to yield a time series that matches closely that which actually occurred.