Thesis (M.Sc.)--York University, 2004. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 277-284). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ99344

Thesis (Ph.D.)--University of Iowa, 2006. / Supervisor: Andrew Williams. Includes bibliographical references (leaves 227-231).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 109-110). Also available in electronic version.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2007. / Includes bibliographical references (leaves 61-68). Also available in electronic version.

Dissertation (PhD)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 105 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 95).

In this work, an interdisciplinary approach has been adopted for the study of: • teaching strategies of an Intelligent Tutoring System, in the paradigm of multiple teaching strategies, and • the use of Computer Algebra Systems (CAS) in teaching problem solving in university mathematics. As a result, the SIMTA (Styles Implemented by Methods Tactics Actions) theoretical framework has been developed to support and sustain teaching strategies in the paradigm of multiple teaching strategies. TeLoDe (TEaching Linear Ordinary Differential Equations), is a prototype Intelligent Tutoring System, teaching the solution of linear second order differential equations with constant coefficients in a novel way. This novel way, which has been empirically tested, has been achieved by augmenting Maple and represents an alternative use of CASs where the human lecturer and Maple are interlocked in a symbiotic and interdependent manner. In SIMTA, the contemporary concept of teaching strategy is rethought and proposed to be viewed at two fundamental levels: • the organisational level • and the operational level. The organisational level deals with the structure of the teaching strategy whereas the operational level deals with the manifestation of that structure. In SIMTA the organisational level is represented by a triple generic structure, method, tactic(s), action(s). A method is a mechanism for structuring the subject matter (e.g. analogy, examples, generalisation, specialisation). Likewise, a tactic is a mechanism for facilitating the interaction (e.g. explicit interaction, implicit interaction). An action is a low level activity such as display this message, ask this question. In SIMTA, the exact manifestation of the above generic structures (analogies, examples, implicit interaction, explicit interaction) depends on the concept of style: different styles result in different manifestations of the same generic structures. Thus, in SIMTA the concept of multiple teaching strategies is seen as merely a collection of teaching strategies manifested under the same style. These strategies operate with the aim of offering alternative representations of the same task at hand and ensuring that the lea~er is active by activating, directing and maintaining exploration. To help demonstrate the feasibility of SIMTA, two styles, the expository style and the , guided discovery style have been formed. The expository style draws on Ausubel's theory of meaningfulleaming, whereas, the guided discovery style draws on Bruner's work. These styles have been implemented in TeLoDe. TeLoDe, incorporates a teaching strategy module, based on a style, and declarative knowledge. Its purpose is threefold: (i) to serve as a research tool for the SIMTA framework, (ii) to serve as a prototype, demonstrating clearly how a 'second generation' CAS which undertakes the procedural aspect of mathematics allowing the human tutor to concentrate on its conceptual aspect, could be developed, (iii) to demonstrate how Maple and human lecturers are given clear roles which are, nevertheless, interdependent in carrying out the teaching of university mathematics. Two small-scale empirical studies were carried out in order to test SIMTA and TeLoDe respectively. The first study involved lecturers whereas the second study was carried out in a classroom environment. The results found from these studies demonstrate that TeLoDe has a potential as a teaching tool for problem solving in university mathematics in a novel way.

This thesis presents two novel algorithms for converting a normalised binary floating point number into a binary logarithmic number with the single-precision of a floating point number. The thesis highlights the importance of logarithmic number systems in real-time DSP applications. A real-time cross-correlation application where logarithmic signal processing is used to simplify the complex computation is presented. The first algorithm presented in this thesis comprises two stages. A piecewise linear approximation to the original logarithmic curve is performed in the first stage and a scaled-down normalised error curve is stored in the second stage. The algorithm requires less than 20 kbits of ROM and a maximum of three small multipliers. The architecture is implemented on Xilinx's Spartan3 and Spartan6 FPGA family. Synthesis results confirm that the algorithm operates at a frequency of 42.3 MHz on a Spartan3 device and 127.8 MHz on a Spartan6. Both solutions have a pipeline latency of two clocks. The operating speed increases to 71.4 MHz and 160 MHz respectively when the pipeline latencies increase to eight clocks. The proposed algorithm is further improved by using a PWL (Piece-Wise Linear) approximation of the transform curve combined with a PWL approximation of a scaled version of the normalized segment error. A hardware approach for reducing the memory with additional XOR gates in the second stage is also presented. The architecture presented uses just one 18k bit Block RAM (BRAM) and synthesis results indicate operating frequencies of 93 and 110 MHz when implemented on the Xilinx Spartan3 and Spartan6 devices respectively. Finally a novel prototype of an FPGA-based four channel correlation velocimetry system is presented. The system operates at a higher sampling frquency than previous published work and outputs the new result after every new sample it receives. The system works at a sampling frequency of 195.31 kHz and a sample resolution of 12 bits. The prototype system calculates a delay in a range of 0 to 2.6 ms with a resolution of 5.12 us.

Ph.D. / Information technology (IT) system development faces increasing challenges as a result of the complexity involved in the large number of interacting, distributed and concurrently executing components of systems. These components range from operating systems and virtual machines, through to the various frameworks, servers and libraries. To continue delivering on the current trend in resource requirements, hardware is increasingly parallel. The parallelisation of hardware indicates that software systems must be enabled to exploit these multicore, symmetric multiprocessing and distributed architectures as they become more mainstream. Parallelisation of IT systems adds to the number, distribution and concurrency of interacting components. In addition, dynamic self-optimising, selfhealing, self-configuring and self-protecting characteristics are required if systems are to continue operating effectively. The environment into which a system is eventually deployed is often either unknown or dynamic. An unknown environment is one where the exact details of resource availability, along with knowledge or control over concurrently executing systems, is not available beforehand. Added to this is a lack of foreknowledge surrounding the system’s environment, which may be dynamic, meaning it is likely to change during the system’s lifetime. Changes to the system’s environment include new infrastructure, different architectures, replacing old hardware and installing or upgrading software. The current approaches to overcoming unknown and dynamic environments tend to be top-down and centralised as is seen in the use of control theory by autonomic computing. There is, however, a growing realisation that centralised approaches add to the brittleness and complexity of the systems. What is needed is the self-adaptivity of an agent based approach, which is able to overcome these challenges relating to unknown and dynamic environments. Nature has dealt with the same challenges in a far more robust way by employing the principles of self-organising systems underpinning the control of complex adaptive systems. An example of nature’s solution is the self-organising system presented by the gene regulatory system coupled to cell fate and the cell cycle in multicellular organisms. Organisms are self-healing, self-protecting, self-optimising and self-configuring. They are also able, through ontogenesis, to self-adapt to their environments and grow to maximise their performance whilst still maintaining function.

In the current manufacturing environment, characterized by diverse change sources (e.g. economical, technological, political, social) and integrated supply chains, success demands close cooperation and coordination between stakeholders and agility. Tools and systems based on software agents, intelligent products and virtual enterprises have been developed to achieve such demands but either because of: (i) focus on a single application; (ii) focus on a single product; (iii) separation between the product and its information; or (iv) focus on a single system characteristic (e.g. hardware, software, architecture, requirements) their use has been limited to trial or academic scenarios. In this thesis a reusable distributed manufacturing monitoring system for harsh environments, capable of addressing traceability and controllability requirements within stakeholders and across high cost and complexity supply chains is presented.