Thesis (Ph.D.) - University of Queensland, 2004. / Includes bibliography.

Thesis (Ph. D.)--University of Oregon, 2005. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 243-261). Also available for download via the World Wide Web; free to University of Oregon users. Also issued online.

Thesis (Ph. D.)--University of Oregon, 2005. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 243-261). Also available for download via the World Wide Web; free to University of Oregon users.

No description available.

No description available.

Magnetic Resonance Imaging (MRI) is a medical imaging technique which is especially sensitive to different soft tissues, producing a good contrast between them. It allows for in vivo visualisation of internal structures in detail and became an indispensable tool in diagnosing and monitoring the brain related diseases and pathologies. Amongst others, MRI can be used to measure random incoherent motion of water molecules, which in turn allows to infer structural information. One of the main challenges in processing and analysing four dimensional diffusion MRI images is low signal quality. To improve the signal quality, either denoising algorithm or angular and spatial regularisations are utilised. Regularisation method based on Laplace--Beltrami smoothing operator was successfully applied to diffusion signal. In this thesis, a new regularisation strength selection scheme for diffusion signal regularisation is introduced. A mathematical model of diffusion signal is used in Monte--Carlo simulations, and a regularisation strength that optimally reconstructs the diffusion signal is sought. The regularisation values found in this research show a different trend than the currently used L-curve analysis, and further improve reconstruction accuracy. Additionally, as an alternative to regularisation methods a backward elimination regression for spherical harmonics is proposed. Instead of using the regularisation term as a low-pass filter, the statistical t-test is classifying regression terms into reliable and corrupted. Four algorithms that use this information are further introduced. As the result, a selective filtering is constructed that retains the angular sharpness of the signal, while at the same time reducing corruptive effect of measurement noise. Finally, a statistical approach for estimating diffusion signal is investigated. Based on the physical properties of water diffusion a prior knowledge for the diffusion signal is constructed. The spherical harmonic transform is then formulated as a Bayesian regression problem. Diffusion signal reconstructed with the addition of such prior knowledge is accurate, noise resilient, and of high quality.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / This paper gives an overview on Telemetry, Tracking and Command (TTC) sub-system that are used onboard some telecommunication satellites. Then, a description of the equipments of such a sub-system is given, together with the main performances.

published_or_final_version / Politics and Public Administration / Doctoral / Doctor of Philosophy

published_or_final_version / Business Administration / Master / Master of Business Administration

Advances in mobile computing technology and software applications have led to an expansion in potential uses for handheld computers for various tasks. One strong application area is in maintenance and inspection. Network Rail has been progressively developing and applying handheld computers to field-based maintenance and inspection operations, with the aims of improving work productivity and quality, and personal and system safety. However, it is clear that these aims so far have been achieved with varying degrees of success. Handheld computer devices have the potential to enhance the procedure of performing the tasks in many different ways. However, the current handheld computers introduced to maintenance and inspection tasks in Network Rail have principally been designed as data entry tools and in most cases the primary objective is to reduce the amount of paper work and the associated costs and errors. This highlights the need for fundamental research into the ways in which handheld computer technologies should be specified, designed and implemented for effective use in a complex distributed environment such as the rail industry. The main purpose of this research was to study the applications of handheld computers in the rail industry and to generate a set of design principles for development of future systems within Network Rail. The findings of this research have contributed to the identification of human factors principles that need to be considered for design and implementation of successful handheld computer applications. A framework was also developed to summarise and organise information and functional requirements of maintenance workers. Investigating maintenance workers’ requirements through interviews and observations emphasised the importance of rail specific spatial information and the benefits of providing this knowledge to maintenance workers through a mobile computing device which is portable and easy to use. However, displaying rail specific spatial information on the small screen of a handheld computer introduces various HCI issues and challenges. These were addressed in part through a programme of experiments, and therefore the final section of this research focused on examining fundamental aspects of presenting rail specific spatial information on handheld computer screens. The main findings from different stages of this research have been collated into a set of recommendations for design and development of usable and useful applications for handheld computer devices in the rail industry.