Includes abstract. / Includes bibliographical references (leaves 89-93). / This study represents a seamless weaving of new and previously seemingly unrelated concepts on Free and Open Source Software (FOSS) participation into an integrated substantive framework. The research demonstrates how patterns of behaviour amongst FOSS participants serve as currency for the acquisition of status. Stages of the Basic Social Process (BSP) that lead to the resolution of the status concern are proposed. The core elements of the BSP are found to be Joining, Learning, Locating, Cultivating and Consolidating. These constructs represent the non-linear stages which the members of the community encountered in their FOSS journey towards acquiring status. The conditions for variation of the constructs are also addressed in this study.

Includes bibliographical references. / Modern Molecular Dynamics force fields, such as the CHARMM36 and GLYCAM06carbohydrate force fields, are parametrised to reproduce behaviours for specific molecules under specific conditions in order to be able to predict the behaviour of similar molecular systems, where there is often no experimental data. Coupled with the sheer number available, this makes choosing the appropriate force field a formidable task. For this reason it is important that modern force fields be regularly compared. Streptococcus pneumoniae is a cause of invasive pneumococcal disease (IPD) such as pneumonia and meningitis in children under five. While there are over 90 pneumococcal serotypes only a handful of these are responsible for disease. Immunisation with the conjugate vaccine PCV7, has markedly decreased invasive pneumoccocal disease. Following PCV7 immunisation, incidences of non-vaccine serotypes, especially serotype19A, have increased.

Recording university lectures through lecture capture systems is increasingly common. However, a single continuous audio recording is often unhelpful for users, who may wish to navigate quickly to a particular part of a lecture, or locate a specific lecture within a set of recordings. A transcript of the recording can enable faster navigation and searching. Automatic speech recognition (ASR) technologies may be used to create automated transcripts, to avoid the significant time and cost involved in manual transcription.

Includes bibliographical references (leaves 109-116). / In a fast moving competitive sector like banking, the customer service department often finds it difficult to keep up with the pace at which customer concerns are raised. On the other hand, the speed at which this department responds to customer concerns determines the difference between keeping a customer and losing one. Thus, most banks have moved to technology to expedite the process of capturing and processing customer complaints. Unfortunately, not every customer serviced by these banks finds the deployed technologies accessible and usable. Among the customers who find technologies in the banks inaccessible and unusable are blind customers. In part, the inaccessibility of technologies used in banks may be attributed to poor requirements engineering. Poorly elicited requirements lead to the design of products which fail to satisfy the needs of the diverse population they service. The purpose of this project is to specify neatly validated requirements using the SMART criterion for a system that can be used to evaluate levels of customer satisfaction with services offered to them by banks. The envisaged system should be able to cater for the needs of the blind customers served by these banks. Data for the study was collected from blind people in a vocational school in Botswana, customer care managers in five different bank brands and the system designers. Data was collected through guided interview sessions, which on average lasted for thirty minutes per respondent. Data from the respondents was analyzed qualitatively and quantitatively. Data was summarized into tables, graphs, diagrams and charts to reveal trends. Data was further analyzed to specify the requirements of a system that allows blind customers to provide feedback to their banks. In an attempt to align the requirements to the specific needs of blind customers the specified requirements were reviewed and validated, guided by the principles of the SMART criterion.

Includes abstract. / Includes bibliographical references (leaves 63-67). / Many universities, libraries, government organisations and companies are implementing digital repositories to collect, preserve, administer and distribute their collections via the World Wide Web. In the process of building these digital archives and collections, images such as maps are often are captured in an uncompressed, high-resolution format to preserve as much detail as possible. This process, of high-resolution archiving gives rise to the problem of providing the end-user with access to these large (high-resolution) images, such as maps. This dissertation investigates methods of storing and delivering large images over the Internet while limiting the amount of data being transferred; and also documents efforts to incorporate large image support within the DSpace platform.

The emergence of ST131 extra-intestinal pathogenic Escherichia coli that are resistant to multiple antibiotics is a growing international health concern. Infections are common, treatment options for antibiotic resistant bacteria are limited and there is no vaccine available. Polysaccharides serve key functions in immune response to bacterial infection. The Opolysaccharides present on the cell surface of gram negative bacteria are antigenic and are associated with specific bacterial serogroups. These are, therefore, a potentially effective target for vaccines. Most ST131 E. coli isolates express the O25b antigen and monoclonal antibodies that are specific to it have been isolated. The chemical structure of O25b has been characterized and differentiated from that of the previously known O25 (or O25a) variety. Relatively little is known about the conformations of O25a and O25b and how they differ, however. As conformation is a factor in antigen-antibody binding, differences between the conformations of these two antigens may be relevant to further research into carbohydrate targeted vaccines and diagnosis techniques for ST131:O25b bacteria. The conformations of polysaccharides are typically dynamic in solution and are difficult to determine empirically. Molecular dynamics simulation provides a means of estimating polysaccharide conformation but the results are critically dependent on the quality of the selected force field. Carbohydrate force fields have matured over the past few decades and CHARMM36 and GLYCAM06 are used extensively for the analysis of bacterial polysaccharides. Studies that compare results from these two widely used force fields are, however, still quite rare. Here we use molecular dynamics simulations of unacetylated, 3 RU oligosaccharide extensions to compare the CHARMM36 and GLYCAM06 force fields and to present an initial analysis of the conformations of the O25a and O25b E. coli antigens. We then apply CHARMM36 molecular dynamics simulation to analogous O- and N- acetylated oligosaccharide extensions to gauge the effect of these groups on the conformations of the two antigens and to compare O25a and O25b. Despite some differences, our CHARMM36 and GLYCAM06 simulations are largely in agreement regarding the conformation of O25a trimers without O- or N-acetylation. Both force fields predict extended, linear antigen conformations. Differences between the two force fields are noted in our analogous study of O25b however: GLYCAM06 favors a collapsed, globular oligosaccharide over a more extended molecule favored by CHARMM36; CHARMM36 and GLYCAM06 predict different preferred dihedral values for a conformationally important, main-chain ɑ-L-Rhap-(1->3)- β-D-Glcp bond; GLYCAM06 favors an anti-Ψ, anti-ω orientation of a side-chain β-D-Glc-(1->6)-ɑD-Glc bond over an anti-Ψ, syn-ω orientation favored by CHARMM36. These findings are in agreement with other studies that indicate the collapse of some oligosaccharides into metastable globular conformations during simulations with GLYCAM06. Our CHARMM36 simulations of O- and N-acetylated, 3 RU oligosaccharide extensions of O25a and O25b indicate large differences between the conformations of the two antigens: First, the O25b trimer favors either a compressed or extended helical conformation in solution whereas the O25a trimer favors a single, extended conformation. Second, O25a and O25b exhibit notably different dihedral values for conformationally important glycosidic bonds that correspond with the reported structural differences between the two antigens. Third, O- and N-acetylation is found to facilitate rotation about a key ɑ-D-Glcp-(1->3)-ɑ-L-Rhap2Ac bond in O25b that, in turn, facilitates the formation of compressed, helical O25b conformations. These compressed conformations are stabilized by intramolecular hydrogen bonds that involve O- and N-acetyl groups. Finally, N-acetyl groups appear to be shielded on the inside of the compressed O25b helix whereas O-acetyl groups appear to be exposed on the outside of the molecule. We postulate that these large conformational differences provide a rationale for the clinically noted differences in cross reactivity of monoclonal antibodies for the O25a and O25b antigens.

Includes abstract. / Includes bibliographical references. / An automatic speech recognition (ASR) system is a software application which recognizes human speech, processes it as input, and displays a text version of the speech as output or uses the input as commands for another application's usage. ASR can either be speaker-dependent or speaker-independent. A speaker-dependent ASR system required every user to perform training before its usage, while speaker-independent ASR requires no prior training before usage...This study involved the evaluation of commercially available English ASR systems, establishing their usability and usefulness among different language groups in South Africa which use English as a common language. Of particular interest was the effect of African accents on the performance of the ASR systems. ASR technology is widely used and researched in the developed world with reported recognition accuracy of up to 99%. However, English spoken with African accents may have adverse effect on the recognition accuracy...

Includes abstract. / Includes bibliographical references (leaves 87-91) / Cultures evolve continuously, and it is therefore vital to track and record these changes, and most importantly of all, manage the resulting huge mass of data such as images, video clips, audio recordings and documents. This thesis examines the design of a Web-based solution, hereafter referred to as the Information Management System (IMS), to handle the efficient, accurate and secure management of a large number of objects.

This thesis describes and reflects on the effectiveness of integrating contextmapping as both a methodology and interaction design practice in order to co-­design digital products with and for developing communities. A Design as research methodology is applied in this study within the specific contexts of a co-design project involving small-­scale urban farmers in Soweto. The final design outcomes of the project are the interaction design documents reflecting the design requirements of a mobile application as well as a low-level prototype demonstrating a number of the identified requirements contained in the documentation. The study assumes a human-centred design ethos that positions problems facing users as contextual, complex and indeterminate and requiring a degree of consideration and understanding by the designer before they can be resolved. The design process applied in this study therefore focused on gaining an understanding of the farmers' life experiences in order to design effective and empathetic technological solutions that will be meaningful and useful to the farmers. For this purpose, contextmapping and interaction design theory, methods and tools were integrated. Examples of this integration include the application of Hassenzahl's Three Level Hierarchy of Needs model to guide the exploration of the farmers' experiences and contexts, the use of contextmapping's Sensitization Phase and generative tools to generate user research data and lastly, contemporary interaction design tools such as problem-­ecology maps, personas and user-journey diagrams to develop and communicate design concepts to the farmers. The study concludes that this integration of contextmapping and interaction design is effective, in particular through its enablement of community participation in contributing meaningfully to the co-­design process while further ensuring that contributions made by the participants are relevant and actionable to the interaction design.

With the demand for recorded lectures to be made available as soon as possible, the University of Cape Town (UCT) needs to find innovative ways of removing bottlenecks in lecture capture workflow and thereby improving turn-around times from capture to publication. UCT utilises Opencast, which is an open source system to manage all the steps in the lecture-capture process. One of the steps involves manual trimming of unwanted segments from the beginning and end of video before it is published. These segments generally contain student chatter. The trimming step of the lecture-capture process has been identified as a bottleneck due to its dependence on staff availability. In this study, we investigate the potential of audio classification to automate this step. A classification model was trained to detect 2 classes: speech and non-speech. Speech represents a single dominant voice, for example, the lecturer, and non-speech represents student chatter, silence and other environmental sounds. In conjunction with the classification model, the first and last instances of the speech class together with their timestamps are detected. These timestamps are used to predict the start and end trim points for the recorded lecture. The classification model achieved a 97.8% accuracy rate at detecting speech from non-speech. The start trim point predictions were very positive, with an average difference of -11.22s from gold standard data. End trim point predictions showed a much greater deviation, with an average difference of 145.16s from gold standard data. Discussions between the lecturer and students, after the lecture, was predominantly the reason for this discrepancy.