Thesis (Ph.D.)(Engineering Management)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Enterprise architecture is the high-level design of the entire business, facilitated by enterprise architects. "Agile enterprise architecture" is the term used in enterprise architecture to describe an architecture that caters for future unknowns, enabling change to occur rapidly without undue resource utilization, yet in a controlled manner and with minimal adverse impact. Some enterprise architects still use outdated, rigid approaches to enterprise architecture which are incompatible with today‟s business environment. In addition, there is limited research into methods that can be applied to measure the agility of enterprise architecture. The current environment is such that there is a need for a more agile approach to developing and measuring enterprise architecture. This work will lead to the creation of a Framework for The Development and Measurement of Agile Enterprise Architecture. In support of the main goal of the development of the framework, a literature review will be conducted focusing on the necessary sub-goals of the research. The first sub-goal of the literature review is to develop a comprehensive definition for enterprise architecture (referred to as EA), as well as discover how it is currently practiced. Thereafter, the literature review will investigate a comprehensive definition for agility and research why it is emerging as a critical topic. The next chapter of the literature review will research how agility fits within the context of EA, uncovering a comprehensive definition for agile EA and the best practices in agile EA development. The final chapter of the literature review will investigate suitable measurement techniques that can be used to assess the level of agility of EA. On completion of the literature review, a preliminary framework will be created using the most important contributions from the literature. An empirical study will be conducted to explore the definitions for EA, agility, agile EA, the methods to measure the agility of EA and the concepts for the development of agile EA summarised in the preliminary framework. Data analysis follows an interpretive and qualitative approach based on four case studies through interviews with systems experts in four South African organizations in one province. Each interviewee was interviewed once. The initial interview with a Principal Consultant on Enterprise Strategy Consulting at organisation # 1 formed the basis of an exploratory study; the results of which were used to refine the research instrument and preliminary framework. Thereafter, a more rigorous empirical study focused on interviews with the Chief Architect, Senior Manager in Advisory Services and an Enterprise Architect at organizations 2, 3 and 4 respectively was conducted. The research follows an inductive approach to capture the interpretive experiences of participants and develop theoretical propositions from them. Following the exploratory pilot study it became necessary to make changes to the preliminary framework and initial survey instrument created. Thereafter, the empirical study consisting of the remaining three cases was conducted to test the important aspects of the framework and literature definitions. The analysis of the results of the empirical study prompted further changes to the theoretical framework and definitions created. The interviews conducted with each of the organizations confirmed the factors for agile EA development as well as the effectiveness of the definitions created in the literature review. The research uncovered that the need for a more agile approach to developing EA and a way to measure the level of agility of EA has become more and more significant in organizations. This begins with a better understanding of EA, agility, how agility fits within the context of EA, as well as appropriate methods to measure agility.

Thesis (Ph. D.)--UCLA, 2004. / Vita. Description based on print version record. Includes bibliographical references (leaves 531-546).

A thesis submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the Degree of Doctor of Philosophy. / Variable speed motors are achieved by varying the voltage of a DC machine or by varying the frequency of an AC machine, the former method being the simpler of the two. DC motors have the major disadvantage of brushes and commutators which require regular downtime for maintenance, a fact already recognised by Tesla [1] in 1888. Thus the AC motor, in particular the induction motor, is of a more rugged design and does not suffer from the commutator problem of its DC counterpart. Recent advances in the technology of the power electronics used to supply a variable frequency to the motor has allowed the induction motor to be a viable alternative to the DC motor in variable speed applications. Problems have been encountered in industry when an inverter is injudiciously selected to be combined with a motor. Such problems were highlighted by difficulties being experienced with some 400 kW inverter drives. The inverters had been bought from one supplier and the motors from another. When this system was coupled together, there was excessive heating in the motors and the overall plant was only able to operate well below its capacity, incurring a substantial weekly loss of income. The motor and inverter were evidently incompatible, and since the inverter could not be modified, the motor was redesigned to make it less susceptible to the harmonics present in the inverter waveform, These problems have led to the development of a variable speed drive simulation package at the University for use by the local industry which can accurately model the complete system of inverter, motor and its associated load. It is envisaged that this package could be used to predict the performance of a drive system and highlight problems that may occur. To be able to do this, an accurate model of the motor is required. This investigation gives the development of an induction motor model which is suitable . for variable speed drive system simulations. The model accounts for the deep bar effect by using lumped parameter circuits and includes saturation of the leakage paths using only information which is typically available from motor design data. A complete analysis is given of the different lumped parameter models and their suitability for use in this application. The thesis also shows the utilisation of the deep bar model to simulate reswitching transients and double cage motors. The author hopes that the models used in the simulation package wallow industry to predict problems prior to their occurrence, alter the designs and thereby avoid costly remanufacture of the system. / Andrew Chakane 2018

A thesis submitted to the Faculty of Engineering at the University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. / Particularly at the higher system voltages, certain faults have been attributed to VFTs. This work presents a full frequency domain mathematical model of the effects likely to be introduced by the application of a thin ferromagnetic coating to the surfaces of the busbars as a means of attenuating these transients. Experimental verification shows the model to perform accurately as an analysis tool for a continuous coated co-axial system. While comparison between the model developed here (based on a planar conductor) and the very accurate Bessel function solution is presented, it must be remembered that it is not feasible to include the effects of coatings in the latter solution. Hence it is used merely as a bench-mark for improvements to the general model. Consideration is also given to the transient skin effect, and this is shown to result in an increased attenuation of VFTs. detectable during high voltage experimentation. The frequency domain model is extended to that of a full travelling wave model for VFTs in GIS. The Fourier technique is used to move between the frequency and time domains. Laboratory results obtained at high voltage.show that this technique will introduce both risetime increase and peak magnitude attenuation of VFTs. As the most frequent faults directly attributable to disconnector operation are known to be faults to earth at the switch, it is noted that the technique proposed in this work is uniquely suited for use in a design strategy that requires totally robust disconnectors at the expense of more severe VFTs in the GIS. The model is used to determine a range of physical characteristics of materials suitable for use in this application. While the characteristics of the most suitable materials have therefore been established, it is concluded that extensive metallurgical experimentation remains before this technique may be economically applied. / Andrew Chakane 2018

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This thesis investigates the feasiblity of using a new microcontroller architecture, the XMOS XS1, in the research and development of control standards for audio distribution networks. This investigation is conducted in the context of an emerging audio distribution network standard, Ethernet Audio/Video Bridging (`Ethernet AVB'), and an emerging audio control standard, AES-64. The thesis describes these emerging standards, the XMOS XS1 architecture (including its associated programming language, XC), and the open-source implementation of an Ethernet AVB streaming audio device based on the XMOS XS1 architecture. It is shown how the XMOS XS1 architecture and its associated features, focusing on the XC language's mechanisms for concurrency, event-driven programming, and integration of C software modules, enable a powerful implementation of the AES-64 control standard. Feasibility is demonstrated by the implementation of an AES-64 protocol stack and its integration into an XMOS XS1-based Ethernet AVB streaming audio device, providing control of Ethernet AVB features and audio hardware, as well as implementations of advanced AES-64 control mechanisms. It is demonstrated that the XMOS XS1 architecture is a compelling platform for the development of audio control standards, and has enabled the implementation of AES-64 connection management and control over standards-compliant Ethernet AVB streaming audio devices where no such implementation previously existed. The research additionally describes a linear design method for applications based on the XMOS XS1 architecture, and provides a baseline implementation reference for the AES-64 control standard where none previously existed.

Thesis (Ph. D.)--Utrecht University, 2007. / "This publication has been submitted as a Ph. D. thesis for the award of the degree of Doctor at Utrecht University, the Netherlands, 16 February 2007"--T.p. verso. Vita. Includes bibliographical references (p. 131-141).

Since the late 1990s the government of Malaysia has increased emphasis on its Intensification of Research in Priority Areas (IRPA) program, focusing scientific research in universities and government research institutes (GRIs) on activities most likely to enhance national economic performance. The IRPA’s main purpose is to fund commercially viable research for the benefit of business. However, its 2001 mid-term review showed its rates and volumes of commercialization and technology transfer (CTT) to be inadequate. This study aimed to explain the perceived low rate of adoption and commercialization of scientific knowledge in manufacturing in Malaysia by exploring the actions of companies, universities and GRIs. Two main models of technical change, the Technik and the STH ones, were used. Fieldwork was carried out in Malaysia. Purposive sampling led to selection of 60 interviewees: 23 managers and professionals from companies, 17 scientists, eight Technology Transfer Office officers, six senior research administrators, three venture capitalists, two journalists and a politician. The interviews were open-ended. It was seen that research findings were not always relevant to company interests, and companies often preferred their own or adopted, sometimes reverse-engineered, technology. Government CTT funds did not help much in with design, prototypes and pilot plants. Inadequate communication and lack of trust influenced the low uptake of research findings. The commercial relevance of much scientific research was questioned. More government support for company risk-taking appeared to be needed. Differences in attitude and poor understanding of policies and principles tended to contribute to low uptake. Managers, professional, scientists, Technology Transfer Officers, senior research administrators, venture capitalists needed more flexibility, knowledge and skills to respond to profit-driven research findings. A specifically Malaysian approach to CTT was advocated.

Indiana University-Purdue University Indianapolis (IUPUI) / There is a strong urge for advanced diagnosis method, especially in high power battery packs and high energy density cell design applications, such as electric vehicle (EV) and hybrid electric vehicle segment, due to safety concerns. Accurate and robust diagnosis methods are required in order to optimize battery charge utilization and improve EV range. Battery faults cause significant model parameter variation affecting battery internal states and output. This work is focused on developing diagnosis method to reliably detect various faults inside lithium-ion cell using electrochemical model based observer and fuzzy logic algorithm, which is implementable in real-time. The internal states and outputs from battery plant model were compared against those from the electrochemical model based observer to generate the residuals. These residuals and states were further used in a fuzzy logic based residual evaluation algorithm in order to detect the battery faults. Simulation results show that the proposed methodology is able to detect various fault types including overcharge, over-discharge and aged battery quickly and reliably, thus providing an effective and accurate way of diagnosing li-ion battery faults.