The research was directed toward the viability of an O(n) algorithm which could decompose an arbitrary signal (sound, vibration etc.) into its time-frequency space. The well known Fourier Transform uses sine and cosine functions (having infinite support on t) as orthonormal basis functions to decompose a signal i(t) in the time domain to F(w) in the frequency . domain, where the Fourier coefficients F(w) are the contributions of each frequency in the original signal. Due to the non-local support of these basis functions, a signal containing a sharp localised transient does not have localised coefficients, but rather coefficients that decay slowly. Another problem is that the coefficients F(w) do not convey any time information. The windowed Fourier Transform, or short-time Fourier Transform, does attempt to resolve the latter, but has had limited success. Wavelets are basis functions, usually mutually orthonormal, having finite support in t and are therefore spatially local. Using non-orthogonal wavelets, the Dominant Scale Transform (DST) designed by the author, decomposes a signal into its approximate time-frequency space. The associated Dominant Scale Algorithm (DSA) has O(n) complexity and is integer-based. These two characteristics make the DSA extremely efficient. The thesis also investigates the problem of converting a music signal into it's equivalent music score. The old problem of speech recognition is also examined. The results obtained from the DST are shown to be consistent with those of other authors who have utilised other methods. The resulting DST coefficients are shown to render the DST particularly useful in speech segmentation (silence regions, voiced speech regions, and frication). Moreover, the Spectrogram Dominant Scale Transform (SDST), formulated from the DST, was shown to approximate the Fourier coefficients over fixed time intervals within vowel regions of human speech. / Thesis (Ph.D.)-University of Natal, Durban, 1994.

The intention of this work is to provide a deeper understanding of the engineering geological behaviour of granite saprolite and how this affects the engineering of such material, with specific reference to the construction of Injaka Dam in the north eastern portion of South Africa Whilst extensive investigation of weathered granites has been carried out internationally, very little detailed research on the nature of this material is documented locally. The construction of Injaka Dam afforded the opportunity to investigate the saprolite in detail. This study was initially submitted to the Department of Geology and Applied Geology at the University of Natal, Durban (renamed the University of KwaZulu-Natal in 2004) to fulfill the requirement of a Master of Science degree in 200 I. Following this submission, and supported by recommendations made by the external examiners and the project supervisor, it was agreed to upgrade the work and submit this thesis for the degree of Doctor of Philosophy. Intensive chemical weathering of granite at Injaka Dam site has resulted in the formation of thick saprolitic deposits overlying the weathered bedrock. The granite forms part of the 3 075 Ma Nelspruit Suite which has been intersected by the African erosion surface. The extensive, multicyclic period of weathering and erosion that formed this surface has resulted in deep (up to 35 m) chemical weathering of the underlying bedrock in this area. The construction of Injaka Dam on this material necessitated a thorough engineering geological investigation to understand the nature of the weathering and the possible influences it exerts on the engineering behaviour of the saprolite. This was accomplished by analysing the weathering of the granite and relating the effects of these weathering processes and changes to the engineering behaviour of the material. By applying various chemical and mineralogical indices to the weathered granite, the intensity of weathering and related changes could be quantified and compared with the engineering behaviour of the material. This was achieved by applying a series of engineering indices to the material and relating these to the quantified weathering changes. In this way tentative extrapolation of the engineering behaviour of the material could be gained and used to predict engineering performance. The resultant effects of the engineering behaviour of the material on the design and construction of the dam are also discussed. / Thesis (Ph.D.)-University of KwaZulu- Natal, 2004.

Behavioural research studies often include a data acquisition process, during which subjects are observed, and the displayed behaviours recorded, and a subsequent analysis process, during which the observed behaviours are analysed. In addition the data acquisition process could occur in real-time, or at a later stage, by referring to a recording of the original session. This dissertation addresses the latter approach through the use of computer based digital video technology. A windows based video analysis system, called VAS, that was developed to assist with the acquisition of observed behaviours from the video, and the analysis thereof is discussed. This is followed by a discussion of the implementation of VAS. Finally the directions for further research are identified, and discussed. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.

Bin packing is a problem with many applications in various industries. This thesis addresses a specific instance of the this problem, known as the Container Packing problem. Special attention is paid to the Pallet Loading problem which is a restricted sub-problem of the general Container Packing problem. Since the Bin Packing problem is NP-complete, it is customary to apply a heuristic measure in order to approximate solutions in a reasonable amount of computation time rather than to attempt to produce optimal results by applying some exact algorithm. Several heuristics are examined for the problems under consideration, and the results produced by each are shown and compared where relevant. / Thesis (M.Sc.)-University of Natal, Durban, 1991.

In logic-based Knowledge Representation and Reasoning (KRR), ontologies are used to represent knowledge about a particular domain of interest in a precise way. The building blocks of ontologies include concepts, relations and objects. Those can be combined to form logical sentences which explicitly describe the domain. With this explicit knowledge one can perform reasoning to derive knowledge that is implicit in the ontology. Description Logics (DLs) are a group of knowledge representation languages with such capabilities that are suitable to represent ontologies. The process of building ontologies has been greatly simpli ed with the advent of graphical ontology editors such as SWOOP, Prote ge and OntoStudio. The result of this is that there are a growing number of ontology engineers attempting to build and develop ontologies. It is frequently the case that errors are introduced while constructing the ontology resulting in undesirable pieces of implicit knowledge that follows from the ontology. As such there is a need to extend current ontology editors with tool support to aid these ontology engineers in correctly designing and debugging their ontologies. Errors such as unsatis able concepts and inconsistent ontologies frequently occur during ontology construction. Ontology Debugging and Repair is concerned with helping the ontology developer to eliminate these errors from the ontology. Much emphasis, in current tools, has been placed on giving explanations as to why these errors occur in the ontology. Less emphasis has been placed on using this information to suggest e cient ways to eliminate the errors. Furthermore, these tools focus mainly on the errors of unsatis able concepts and inconsistent ontologies. In this dissertation we ll an important gap in the area by contributing an alternative approach to ontology debugging and repair for the more general error of a list of unwanted sentences. Errors such as unsatis able concepts and inconsistent ontologies can be represented as unwanted sentences in the ontology. Our approach not only considers the explanation of the unwanted sentences but also the identi cation of repair strategies to eliminate these unwanted sentences from the ontology. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2010.

A problem currently facing South Africa is the large number of poorly educated or uneducated people in many parts of the country. Distance education has proven to be an apt solution to this problem However, one of the numerous constraints associated with studying at a distance is insufficient communication between students and lecturers and the lack of peer interaction. The integration of Computer Mediated Communications (CMC) in the delivery of distance education courses world-wide has proved to be a means of alleviating this communication problem. The study presented in this thesis examines the technical feasibility of implementing CMC in the delivery of South African distance education courses as a solution to the communication problems experienced by distance learners in this country. For this purpose a system was developed and implemented at a South African distance education institution namely, Natal College of Education in Pietermaritzburg. Based on this implementation a technical evaluation of the feasibility of CMC in the instruction of distance education courses within a South African infrastructure was examined. As a result of this study we have been able to: • Determine the technical problems associated with the implementation of a CMC system in a South African distance education environment. • Identify possible solutions to these technical problems • Define a set of criteria, which if met by a CMC system would ensure the technical feasibility of the system as a solution to the communication problems experienced by South African distance learners. • Determine the effects of students' attitudes towards computers on their use of the CMC system. • Determine the effect of CMC on students' attitudes towards computers. • Identify any additional factors, besides technical issues, which need to be taken into account when implementing a CMC system. / Thesis (M.Sc)-University of Natal, Pietermaritzburg, 1996.

Thesis (MSc)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: In this thesis, we present a technique for the automatic detection of image orientation using Support Vector Machines (SVMs). SVMs are able to handle feature spaces of high dimension and automatically choose the most discriminative features for classification. We investigate the use of various kernels, including heavy tailed RBF kernels. We compare the classification performance of SVMs with the performance of multilayer perceptrons and a Bayesian classifier. Our results show that SVMs out perform both of these methods in the classification of individual images. We also implement an application for the classification of film rolls in a photographic workflow environment with 100% classification accuracy. / AFRIKAANSE OPSOMMING: In hierdie tesis, gebruik ons 'n tegniek vir die automatiese klassifisering van beeldoriëntasie deur middel van Support Vector Machines (SVM's). SVM's kan kenmerkruimtes van 'n hoë dimensie hanteer en kan automaties die mees belangrike kenmerke vir klassifikasie kies. Ons vors die gebruik van verskeie kerne, insluitende RBF-kerne, na. Ons vergelyk die klassifiseringsresultate van SVM's met die van multilaagperseptrone en 'n Bayes-klassifiseerder. Ons bewys dat SVM's beter resultate gee as beide van hierdie metodes vir die klassifikasie van individuele beelde. Ons implementeer ook a toepassing vir die klassifisering van rolle film in a fotografiese werkvloei-omgewing met 100% klassifikasie akuraatheid.

Thesis (MSc (Mathematical Sciences)--University of Stellenbosch, 2006. / Formal methods, such as model checking, have the potential to improve the reliablility of software. Abstract models of systems are subjected to formal analysis, often showing subtle defects not discovered by traditional testing.

Thesis (MSc (Mathematical Sciences. Computer SCience))--University of Stellenbosch, 2009. / In this thesis we consider the dynamic path planning problem for robotics. The dynamic path planning problem, in short, is the task of determining an optimal path, in terms of minimising a given cost function, from one location to another within a known environment of moving obstacles. Our goal is to investigate a number of well-known path planning algorithms, to determine for which circumstances a particular algorithm is best suited, and to propose changes to existing algorithms to make them perform better in dynamic environments. At this stage no thorough comparison of theoretical and actual running times of path planning algorithms exist. Our main goal is to address this shortcoming by comparing some of the wellknown path planning algorithms and our own improvements to these path planning algorithms in a simulation environment. We show that the visibility graph representation of the environment combined with the A* algorithm provides very good results for both path length and computational cost, for a relatively small number of obstacles. As for a grid representation of the environment, we show that the A* algorithm produces good paths in terms of length and the amount of rotation and it requires less computation than dynamic algorithms such as D* and D* Lite.

Thesis (MSc (Computer Science))--University of Stellenbosch, 2009. / Super cially realistic worlds can easily be created using fractal landscapes. Such landscapes are limited in that real-world geological features such as caves and overhangs are impossible using a standard height eld representation. Interactive, realistic simulation of terrain evolution on such landscapes has proved elusive and does not generally provide direct control over the placement of landscape features. This thesis presents an interactive terrain design system, which enables the user to generate localised, speci c terrain features, as well as generalised global characteristics. A fully volumetric terrain representation is used to allow varied three dimensional terrain features. A hybrid rendering algorithm is employed to e ciently render the volumetric data set, while allowing interactive terrain deformation. Small terrain deformation is enabled using voxel carving, while larger terrain features is generated using an adoption of the Wires algorithm. A fractal river network generation technique is presented and adopted for voxel terrain. These tools provide the user with interactive feedback to allow for more dynamic terrain design.