Dans cette thèse, nous nous sommes intéressés au problème de codage de sources avec information adjacente au décodeur seulement. Plus précisément, nous avons considéré le cas où la distribution jointe entre la source et l'information adjacente n'est pas bien connue. Dans ce contexte, pour un problème de codage sans pertes, nous avons d'abord effectué une analyse de performance à l'aide d'outils de la théorie de l'information. Nous avons ensuite proposé un schéma de codage pratique efficace malgré le manque de connaissance sur la distribution de probabilité jointe. Ce schéma de codage s'appuie sur des codes LDPC non-binaires et sur un algorithme de type Espérance-Maximisation. Le problème du schéma de codage proposé, c'est que les codes LDPC non-binaires utilisés doivent être performants. C'est à dire qu'ils doivent être construits à partir de distributions de degrés qui permettent d'atteindre un débit proche des performances théoriques. Nous avons donc proposé une méthode d'optimisation des distributions de degrés des codes LDPC. Enfin, nous nous sommes intéressés à un cas de codage avec pertes. Nous avons supposé que le modèle de corrélation entre la source et l'information adjacente était décrit par un modèle de Markov caché à émissions Gaussiennes. Pour ce modèle, nous avons également effectué une analyse de performance, puis nous avons proposé un schéma de codage pratique. Ce schéma de codage s'appuie sur des codes LDPC non-binaires et sur une reconstruction MMSE. Ces deux composantes exploitent la structure avec mémoire du modèle de Markov caché. / In this thesis, we considered the problem of source coding with side information available at the decoder only. More in details, we considered the case where the joint distribution between the source and the side information is not perfectly known. In this context, we performed a performance analysis of the lossless source coding scheme. This performance analysis was realized from information theory tools. Then, we proposed a practical coding scheme able to deal with the uncertainty on the joint probability distribution. This coding scheme is based on non-binary LDPC codes and on an Expectation-Maximization algorithm. For this problem, a key issue is to design efficient LDPC codes. In particular, good code degree distributions have to be selected. Consequently, we proposed an optimization method for the selection of good degree distributions. To finish, we considered a lossy coding scheme. In this case, we assumed that the correlation channel between the source and the side information is described by a Hidden Markov Model with Gaussian emissions. For this model, we performed again some performance analysis and proposed a practical coding scheme. The proposed scheme is based on non-binary LDPC codes and on MMSE reconstruction using an MCMC method. In our solution, these two components are able to exploit the memory induced by the Hidden Markov model.

This research looks at the best practices applied by forensic investigators in conducting lifestyle audits on white collar crime suspects. The researcher explored, firstly, how a lifestyle audit relates to white collar crime investigations; secondly, the best practices in performing lifestyle audits on white collar crime suspects, and lastly, the various sources of information available to forensic investigators when conducting a lifestyle audit of a white collar crime suspect. As lifestyle audits will serve as an investigative tool in future forensic investigations into white collar crime, this study’s aim was to understand and create an awareness of the current best practices applied by forensic investigators within private sector forensic investigation practices while conducting lifestyle audits during white collar crime investigations. It also makes available research data regarding the concept of lifestyle audits in white collar crime investigations, the implementation of these audits, the benefits, and the best practices of these audits. The general purpose of this study was to provide practical recommendations on the best practices for lifestyle audits for forensic investigators within private sector. / Criminology and Security Science / M. Tech. (Forensic Investigation)

The purpose of this study was to explore the knowledge, attitudes and behaviours regarding HIV and AIDS of university in Zimbabwe using the Health Belief Model (HBM) as the theoretical framework. The ultimate aim was to find out how at risk university students were of contracting HIV and AIDS. A quantitative, non-experimental descriptive, explorative and correlational research design was used, using self-designed questionnaires for data collection. Respondents were sampled through systemic stratified random sampling resulting in 403 undergraduate university students. Descriptive and inferential statistics were calculated using SPSS version 21 software program. Most students were knowledgeable about HIV transmission; the prevention of HIV and AIDS and sexual risk behaviours pertaining to HIV transmission. Students also did show positive attitudes towards PLHIV. Most students did not perceive themselves to be at high of contracting HIV and AIDS. Up to 52% who were sexually active had more than one sexual partner. The respondents knew that HIV and AIDS were not treatable but continued to indulge in risky sexual behaviours. Most respondents received information about HIV and AIDS from the media and peers. The findings would assist policy makers, programme planners and educators in developing in developing and implementing programmes to improve the health of university students. / Health Studies / M.A. (Health Studies)

The purpose of this study was to explore the knowledge, attitudes and behaviours regarding HIV and AIDS of university in Zimbabwe using the Health Belief Model (HBM) as the theoretical framework. The ultimate aim was to find out how at risk university students were of contracting HIV and AIDS. A quantitative, non-experimental descriptive, explorative and correlational research design was used, using self-designed questionnaires for data collection. Respondents were sampled through systemic stratified random sampling resulting in 403 undergraduate university students. Descriptive and inferential statistics were calculated using SPSS version 21 software program. Most students were knowledgeable about HIV transmission; the prevention of HIV and AIDS and sexual risk behaviours pertaining to HIV transmission. Students also did show positive attitudes towards PLHIV. Most students did not perceive themselves to be at high of contracting HIV and AIDS. Up to 52% who were sexually active had more than one sexual partner. The respondents knew that HIV and AIDS were not treatable but continued to indulge in risky sexual behaviours. Most respondents received information about HIV and AIDS from the media and peers. The findings would assist policy makers, programme planners and educators in developing in developing and implementing programmes to improve the health of university students. / Health Studies / M.A. (Health Studies)

Made available in DSpace on 2016-06-02T19:16:31Z (GMT). No. of bitstreams: 1 4227.pdf: 8156408 bytes, checksum: 893190bd5ad8dc830580170738cd0a79 (MD5) Previous issue date: 2012-02-24 / The rapid progress of Science and Technology in recent decades coupled with the advent of information and communication technologies has led to tremendous growth in the volume of information produced and made available, with replacement and diversity of formats. Therefore, on the one hand, there has been the expansion in the supply of information sources by commercial producers, scientific and institutional facilities with great access to information, as well as the changing behavior of users who have become more virtual and independent as they go less to the library to carry out their search activities, location and obtain information and documents; on the other hand, the lack of the users' competence or difficulty in dealing with these new information resources. Against this changing background, it is important that users and librarians play new roles. The user must be able to be autonomous in the information universe, and the librarian should play the role of a mediator. It is identified as the problem of this research that a large number of existing sources of information available in the area of Science and Technology in its various media and types is often an impediment for users to identify, be aware of and access them independently, efficiently and effectively. Thus, the aims of this research are: to investigate and identify trends for the application of tools to mediate the processes of searching, accessing and learning the use of information sources in academic libraries; to consider proposals in the use of tools for online bibliographic databases and suggest tool tips, their features and capabilities of their use that may be adopted by academic libraries. The methodology used was exploratory research and the method adopted was the content analysis through a quantitative and qualitative approach, including the collection of specific data regarding the availability of tools to mediate the use of sources of information on websites of university libraries. The study sample consisted of 24 libraries selected from the best national and international universities (Webometrics Ranking of World s Universities, World University Rankings 2011-2012, Índice Geral de Cursos). The results identified a general overview of how university libraries are conducting the mediation of information sources, especially in relation to bibliographic databases, and considering the tools that represent an incremental innovation in how libraries can play their roles as mediators, encouraging the development of competence in information from their users and providing tools for the process of knowledge generation and thereby help users to make the best use of technology and information sources in their academic and professional activities. / O acelerado progresso da Ciência e Tecnologia nas recentes décadas, aliado ao advento das tecnologias de informação e comunicação, acarretou um enorme crescimento do volume de informações produzidas e disponibilizadas, com substituição e diversidade de formatos. Consequentemente, por um lado, houve a ampliação na oferta de fontes de informação por parte de produtores comerciais, científicos e institucionais, com grandes facilidades de acesso à informação, como também a mudança no comportamento dos usuários que se tornaram mais virtuais e independentes, deslocando-se menos à biblioteca para a realização de suas atividades de busca, localização e obtenção de informação e documentos; por outro, a falta de competência ou dificuldade dos usuários diante desses novos recursos informacionais. Diante desse cenário de mudanças, considera-se importante que usuário e bibliotecário desempenhem novos papeis. O primeiro precisa ser capacitado para sua autonomia no universo informacional e o segundo, por sua vez, para exercer sua função de mediador. Identifica-se, como problema desta pesquisa, que um grande número existente de fontes de informação disponíveis na área de Ciência e Tecnologia, em seus variados suportes e tipologia, é muitas vezes um dificultador para que os usuários consigam identificá-las, conhecê-las e acessá-las de forma autônoma, eficiente e eficaz. Dessa forma, os objetivos desta pesquisa são: investigar e identificar tendências de aplicação de ferramentas para as atividades de mediação dos processos de busca, acesso e aprendizagem do uso de fontes de informação em bibliotecas universitárias; examinar propostas de uso das ferramentas para as bases de dados bibliográficas on-line e apontar sugestões de ferramentas, suas características e potencialidades de seu uso e que poderão ser adotadas por bibliotecas universitárias. A metodologia utilizada foi a pesquisa exploratória e, como método, a análise de conteúdo, com abordagem quantitativa e qualitativa, incluindo a coleta de dados específicos referentes à disponibilização de ferramentas para mediação do uso de fontes de informação em websites de bibliotecas universitárias. A amostra pesquisada foi composta por 24 bibliotecas selecionadas de melhores universidades internacionais e nacionais (Webometrics Ranking of World s Universities, World University Rankings 2011-2012, Índice Geral de Cursos). Como resultado, identificou-se um panorama geral de como as bibliotecas universitárias estão realizando o processo de mediação das fontes de informação, especialmente em relação às bases de dados bibliográficas, considerando as ferramentas que representam uma inovação incremental na forma de como elas podem desempenhar seus papeis de mediadoras, incentivando o desenvolvimento da competência em informação de seus usuários e instrumentalizando o processo de geração do conhecimento, e, com isso, contribuir para que eles façam o melhor uso possível das tecnologias e fontes de informação em suas atividades acadêmicas e profissionais.

The study sought to explore and describe the risk behaviour regarding HIV transmission among youth in Bulawayo, their knowledge of HIV transmission and the sources of information on HIV transmission accessible to them. A quantitative, descriptive exploratory design was used and 238 youth from three secondary schools in Bulawayo, the second largest city in Zimbabwe were the respondents. The Health Belief Model (HBM) was used to facilitate and acquire insight into the risk behaviour among the youth. The inferences drawn from the study were that youth have inadequate knowledge about HIV transmission and therefore do not fully understand their risk of infection. Youth also find shyness and fear of rejection serious barriers to communicating openly about sexuality, sexual and HIV/AIDS issues. The findings of the study have implications for programmes to limit HIV transmission among youth and should assist policymakers and educators in developing and implementing such programmes in order to improve the health of youth in Zimbabwe. / Health Studies / M.A. (Health Studies)

The study sought to explore and describe the risk behaviour regarding HIV transmission among youth in Bulawayo, their knowledge of HIV transmission and the sources of information on HIV transmission accessible to them. A quantitative, descriptive exploratory design was used and 238 youth from three secondary schools in Bulawayo, the second largest city in Zimbabwe were the respondents. The Health Belief Model (HBM) was used to facilitate and acquire insight into the risk behaviour among the youth. The inferences drawn from the study were that youth have inadequate knowledge about HIV transmission and therefore do not fully understand their risk of infection. Youth also find shyness and fear of rejection serious barriers to communicating openly about sexuality, sexual and HIV/AIDS issues. The findings of the study have implications for programmes to limit HIV transmission among youth and should assist policymakers and educators in developing and implementing such programmes in order to improve the health of youth in Zimbabwe. / Health Studies / M.A. (Health Studies)

Introducción. El objetivo del presente estudio es determinar si existe correlación entre los conocimientos sobre las consecuencias de la obesidad y el grado de actividad física de las personas. Métodos. Se realizó un estudio transversal analítico durante los años 2013 y 2014. Participaron 215 alumnos de pregrado seleccionados por conveniencia no relacionados a carreras del campo de la salud en una universidad de Lima, Perú. Se evaluó el grado de actividad física utilizando el International Physical Activity Questionnaire (IPAQ) y el nivel de conocimientos sobre consecuencias de la obesidad utilizando la escala Obesity Risk Knowledge-10 (ORK-10). También, se consignó las fuentes de información de donde obtuvieron el conocimiento para responder dicho cuestionario. Resultados. La mediana de edad fue 20 (rango intercuartílico=4) y 63% eran mujeres. De acuerdo al IPAQ, 53,9% realizaban actividad física alta, 35,4%, moderada y 10,7%, leve. Se encontró una correlación muy baja (rs=0,06) entre el puntaje del ORK-10 y la cantidad de equivalentes metabólicos/minuto consumidos por semana, pero no era significativa (p=0,38). Las personas informadas por medios de comunicación y por personal de salud obtuvieron mayores puntajes en el ORK- 10 que quienes se informaron por otras vías (p<0,05). Conclusiones. La correlación entre los conocimientos sobre consecuencias de la obesidad y el grado de actividad física es muy baja. Es necesario utilizar enfoques multidisciplinarios que incluyan todos los determinantes de la realización de actividad física para poder lograr cambios en la conducta de la población.