Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 69-72).

Thesis (M. Sc.)--York University, 2001. Graduate Programme in Computer Science. / Typescript. Includes bibliographical references (leaves 155-159). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ71641.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: computation pushdown; XML; order-based Xquery processing; relational database; ordered SQL queries; data model mapping; XQuery; XML data mapping; SQL; XML algebra rewrite rules; XML document order. Includes bibliographical references (p. 64-67).

Laser-Induced Breakdown spectroscopy (LIBS) and Laser-Induced Thermal Emission (LITE) emission based laser remote sensing were investigated with the application to the remote measurements of trace chemical species. In particular, UVvisible LIBS and Mid-IR LITE systems were developed and measurements of remote targets and chemical surfaces were studied. The propagation through the atmosphere of the multi-wavelength backscattered LIBS and LITE optical spectrum with atmospheric absorption effects on the returned lidar signal was investigated. An enhanced model of the atmospheric effects on emission-based laser-remote sensing was developed and found to be consistent and in agreement with our experimental results. LITE measurements were performed which involved heating a remote hard target and recording the vibrational band emission spectra produced. Sample heating was carried out using a 1.5W cw-CO2 10.6 μm wavelength laser, and a 9W cw-diode laser operating at 809nm. The emission spectra over the wavelength range of 8 to 14 μm was observed which can be potentially used to detect and identify chemical composition of the target. LITE spectra of DMMP and DIMP (chemical agent simulants), paints, and energetic materials on various substrates were measured for the first time. A LIBS study was carried out with a 1.064 μm Nd:YAG laser (10 ns pulses, 50mJ per pulse) and remote LIBS measurements were performed for aluminum, copper, steel and plastics over the spectral range of 200 – 1000nm. LIBS measurements as a function of range were studied, and compared to a modified lidar equation suitable for emission based lidar remote sensing. A computer simulation model was developed for emission-based LIDAR remote sensing such as LIBS and LITE. This involved the development and modification of atmospheric transmission modeling programs which use the HITRAN, PNNL and other atmospheric spectral databases to model the transmission of the atmosphere over a wide range of wavelengths from the deep-UV near 200 nm to the mid-IR near 14 microns. A comparison of HITRAN simulations with the PNNL database calculated spectra was carried out and used for the first time for improvements of the HITRAN database line intensities. In addition, a Principal Component Analysis (PCA) of the LIBS and LITE lidar return signal as a function of range was performed. This PCA analysis showed, for the first time, the degradation of the chemical selectivity (i.e. identification capability) of the emission lidar system as the range was increased and the effect of atmospheric absorption spectral lines on the propagated LIBS and LITE lidar multi-wavelength spectral signal.

published_or_final_version / Computer Science / Doctoral / Doctor of Philosophy

In many emerging applications, such as sensor networks, location-based services, and data integration, the database is inherently uncertain. To handle a large amount of uncertain data, probabilistic databases have been recently proposed, where probabilistic queries are enabled to provide answers with statistical guarantees. In this thesis, we study the important issues of managing the quality of a probabilistic database. We first address the problem of measuring the ambiguity, or quality, of a probabilistic query. This is accomplished by computing the PWS-quality score, a recently proposed measure for quantifying the ambiguity of query answers under the possible world semantics. We study the computation of the PWS-quality for the top-k query. This problem is not trivial, since directly computing the top-k query score is computationally expensive. To tackle this challenge, we propose efficient approximate algorithms for deriving the quality score of a top-k query. We have performed experiments on both synthetic and real data to validate their performance and accuracy. Our second contribution is to study how to use the PWS-quality score to coordinate the process of cleaning uncertain data. Removing ambiguous data from a probabilistic database can often give us a higher-quality query result. However, this operation requires some external knowledge (e.g., an updated value from a sensor source), and is thus not without cost. It is important to choose the correct object to clean, in order to (1) achieve a high quality gain, and (2) incur a low cleaning cost. In this thesis, we examine different cleaning methods for a probabilistic top-k query. We also study an interesting problem where different query users have their own budgets available for cleaning. We demonstrate how an optimal solution, in terms of the lowest cleaning costs, can be achieved, for probabilistic range and maximum queries. An extensive evaluation reveals that these solutions are highly efficient and accurate. / published_or_final_version / Computer Science / Master / Master of Philosophy

This thesis aimed to evaluate the feasibility and utility of a sickle cell disease registry for clinical patient management and research. Five hospitals out of nine in the North West London health region participated in the registry, with 78 percent coverage of the sickle cell disease population. There was 80% case ascertainment in participating hospitals. Aggregated anonymised demographic and diagnostic data was collected for all haemoglobinopathy patients. This provided the core dataset for quantifying prevalence of sickle cell and thalassaemia and mapping local hospital workloads and service requirements. Thirteen percent of HbSS adult patients were taking hydroxycarbamide. The cohort of patients treated with hydroxycarbamide was evaluated. Sixty two of the 80 patients started on treatment were included. Follow-up was censored after 9 years, totalling 249 person-years of data with a median follow-up of three years (IQR, 1-6). Results showed that haematological benefits were maintained in the long-term with treatment, but evidence of long-term clinical effectiveness was less strong. This appeared to be due to the patterns of clinical management in everyday practice. Patients tend to be treated with modest doses of hydroxycarbamide due to intolerance or inability to attain or maintain maximum tolerated dose. For example maximum tolerated dose was the aim of treatment for 91% of patients but it was achieved for 65% of participants. Non- compliance with treatment and monitoring schedule was the main reason for non- attainment. Results suggest that it is sensible to strive for maximum tolerated dose to ensure therapy remains effective, but with more realistic expectations of the dose patients can attain and maintain. Doses in adult patients average 20mg/kg/day and 25mg/kg/day in children. Adult patients may be able to achieve a higher dose, if there was more stringent monitoring and improved management of non-compliance. The North West London HU Sub-Registry proved useful for measuring long-term effectiveness and tolerability of hydroxycarbamide. Routinely collected data was utilized for both clinical management and research purposes. The novelty lay in examination of the nuances of routine clinical practice. An electronic patient record was developed as a clinical management tool. It is the first study reporting long-term outcomes for UK sickle cell disease patients on hydroxycarbamide. Findings should help clinicians devise effective treatment protocols and strategies for managing patients commenced on this therapy. Interventions need to be targeted at increasing utilisation, patient adherence and persistence with treatment. The electronic patient record could be used to maximise treatment benefit and improve adherence. More effective involvement of the multidisciplinary team and primary care colleagues in patient education and management should improve usage. Patients and carers need up to date and easy to assimilate information to make informed decisions about treatment options. Maintaining a SCD registry is challenging. Models which operate as clinical information systems provide an incentive for participation. These enable active involvement of local care providers in registry management and the ability to keep and utilize their own data. Clinicians require accurate and current data for patient management and to enable them to benchmark their local outcomes against national outcomes and care standards.

Thesis (DTech. degree in Computer Science and Data Processing: Software Development.)--Tshwane University of Technology, 2012. / Based on the fundamental assumption that individuals view their privacy differently, this study attempts to find a solution on how to protect the personal information of an individual stored in a relational database system against privacy violations. Secondly, to determine how the Hippocratic principles can be effectively applied to give individuals better control over their personal information, while at the same time allowing the organisation to process its transactions on the same personalised information. In answering these problems, the study established a set of extended principles to which the collection and the use of personal data should strictly hold.

published_or_final_version / abstract / toc / Computer Science and Information Systems / Master / Master of Philosophy

published_or_final_version / Architecture / Master / Master of Philosophy