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Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2007. / Committee Chair: Dovrolis, Constantine; Committee Member: Ammar, Mostafa; Committee Member: Schwan, Karsten; Committee Member: Steenkiste, Peter; Committee Member: Zegura, Ellen.

Thesis (Ph. D.)--Computing, Georgia Institute of Technology, 2006. / Dr. Mostafa Ammar, Committee Member ; Dr. Mark Crovella, Committee Member ; Dr. Constantinos Dovrolis, Committee Member ; Dr. Ellen Zegura, Committee Chair ; Dr. Jun Xu, Committee Chair. Vita. Includes bibliographical references.

O trabalho apresentado sob o título \"Análise e Síntese de Sistemas Multiplexados: Uma Abordagem de Confiabilidade e Manutenabilidade Operacional\" tem como objetivo propor um modelo prático para a manutenção, baseado na confiabilidade e manutenabilidade de componentes. Os dados desse trabalho foram obtidos através de relatórios gerenciais da Empresa de Telecomunicações de São Paulo S/A, no período de janeiro/05 a junho/06, para as topologias de rede em anel e ponto a ponto da cidade de São Paulo, municípios da Grande São Paulo, Vale do Paraíba e Litoral do Estado de São Paulo. Com esses dados, foi utilizado o algoritmo de Weibull, cujo modelo probabilístico permite modelar vários tipos de resultados experimentais e operacionais. Dessa forma, foram determinados a confiabilidade operacional, o Tempo Médio de Bom Funcionamento (MTTF), a manutenabilidade, o Tempo Médio de Reparo (MTTR) e a disponibilidade para os componentes da rede externa óptica e dos equipamentos de rede da topologia de rede em anel e ponto a ponto. Observou-se que o equipamento de rede de Multiplexação Densa por Divisão do Comprimento de Onda (DWDM) apresenta uma confiabilidade operacional maior que a dos Equipamentos de Rede Tradicionais (ERT), independente da topologia de rede utilizada. Comparando-se o custo de implantação de uma rede óptica com DWDM e ERT, a uma taxa de transmissão de 2,5 Gbps, pode ser verificado que o custo é aproximadamente sete vezes menor quando se utiliza a rede óptica com DWDM. Por fim, foi feita uma comparação entre o custo total e médio da manutenção corretiva e preventiva para as topologias analisadas. Assim, pode ser concluído que a tecnologia DWDM é a opção mais vantajosa em termos de confiabilidade e manutenabilidade em relação ao ERT. / The work presented under the heading \"Analysis and Synthesis of Multiplexed Systems: An Approach of Reliability and Operational Maintainability\" has as objective to consider a practical model for the maintenance, based on the reliability and maintainability of components. The data of this work had been gotten through management reports of the Company of Telecommunications of São Paulo S/A, in the period of january/05 to june/06, for the in ring and point to point network topologies of the city of São Paulo, cities of the Great São Paulo, Valley of Paraíba and the coast of the State of São Paulo. With these data, it was used the algorithm of Weibull, whose probabilistic model allows to model many types of experimentals and operationals results. Of this form, were determined the operational reliability, the Mean Time To Failure (MTTF), the maintainability, the Mean Time To Repair (MTTR) and the availability for the components of the fiber optic external network and the network equipments of the in ring and point-to-point network topology. It was observed that the network equipment of Dense Wavelength Division Multiplexing (DWDM) presents a greater operational reliability that the Traditionals Network Equipments (ERT), independent of the network topology used. Comparing itself the cost of implantation of an fiber optic network with DWDM and ERT, to a rate of transmission of 2,5 Gbps, it could be verified that the cost is approximately seven times lesser when it is used the fiber optic network with DWDM. Finally, a comparison between the total and average cost of the corrective and preventive maintenance for the analyzed topologies was made. So, it can be concluded that the technology DWDM is the option most advantageous in terms of reliability and maintainability in relation to the ERT.

O trabalho apresentado sob o título \"Análise e Síntese de Sistemas Multiplexados: Uma Abordagem de Confiabilidade e Manutenabilidade Operacional\" tem como objetivo propor um modelo prático para a manutenção, baseado na confiabilidade e manutenabilidade de componentes. Os dados desse trabalho foram obtidos através de relatórios gerenciais da Empresa de Telecomunicações de São Paulo S/A, no período de janeiro/05 a junho/06, para as topologias de rede em anel e ponto a ponto da cidade de São Paulo, municípios da Grande São Paulo, Vale do Paraíba e Litoral do Estado de São Paulo. Com esses dados, foi utilizado o algoritmo de Weibull, cujo modelo probabilístico permite modelar vários tipos de resultados experimentais e operacionais. Dessa forma, foram determinados a confiabilidade operacional, o Tempo Médio de Bom Funcionamento (MTTF), a manutenabilidade, o Tempo Médio de Reparo (MTTR) e a disponibilidade para os componentes da rede externa óptica e dos equipamentos de rede da topologia de rede em anel e ponto a ponto. Observou-se que o equipamento de rede de Multiplexação Densa por Divisão do Comprimento de Onda (DWDM) apresenta uma confiabilidade operacional maior que a dos Equipamentos de Rede Tradicionais (ERT), independente da topologia de rede utilizada. Comparando-se o custo de implantação de uma rede óptica com DWDM e ERT, a uma taxa de transmissão de 2,5 Gbps, pode ser verificado que o custo é aproximadamente sete vezes menor quando se utiliza a rede óptica com DWDM. Por fim, foi feita uma comparação entre o custo total e médio da manutenção corretiva e preventiva para as topologias analisadas. Assim, pode ser concluído que a tecnologia DWDM é a opção mais vantajosa em termos de confiabilidade e manutenabilidade em relação ao ERT. / The work presented under the heading \"Analysis and Synthesis of Multiplexed Systems: An Approach of Reliability and Operational Maintainability\" has as objective to consider a practical model for the maintenance, based on the reliability and maintainability of components. The data of this work had been gotten through management reports of the Company of Telecommunications of São Paulo S/A, in the period of january/05 to june/06, for the in ring and point to point network topologies of the city of São Paulo, cities of the Great São Paulo, Valley of Paraíba and the coast of the State of São Paulo. With these data, it was used the algorithm of Weibull, whose probabilistic model allows to model many types of experimentals and operationals results. Of this form, were determined the operational reliability, the Mean Time To Failure (MTTF), the maintainability, the Mean Time To Repair (MTTR) and the availability for the components of the fiber optic external network and the network equipments of the in ring and point-to-point network topology. It was observed that the network equipment of Dense Wavelength Division Multiplexing (DWDM) presents a greater operational reliability that the Traditionals Network Equipments (ERT), independent of the network topology used. Comparing itself the cost of implantation of an fiber optic network with DWDM and ERT, to a rate of transmission of 2,5 Gbps, it could be verified that the cost is approximately seven times lesser when it is used the fiber optic network with DWDM. Finally, a comparison between the total and average cost of the corrective and preventive maintenance for the analyzed topologies was made. So, it can be concluded that the technology DWDM is the option most advantageous in terms of reliability and maintainability in relation to the ERT.

This diploma thesis deals with optic fiber connectors and their influence on transmissions realized via fiber optics. Optical fibers and lightguides play the key role in telecommunications because of constant demands of higher bandwidth and data rates. Original metalic wires do not meet market requirements and so the fiber optics are more and more being used. There are various types of fibers and there are also many ways of connections. This work deals with demountable way of connection – optical connectors, which have the biggest influence on a total attenuation and route length. Connector has to meet various requirements such as cleannes, quality, mechanical construction and ferrule polishing.

Thesis (MEd (Curriculum Studies))--University of Stellenbosch, 2009. / The research was done in a period of curriculum transformation and reform in South Africa, a period during which teachers attended many interventions by service providers other than the education department to sharpen their skills. In this study, I investigate teacher professional development and professional development programmes using two case studies, MTN-SUNSTEP (Mobile Telecommunications Network – Stellenbosch University Schools Technology in Electronics Programme) and SWAP (Schools Water Project). These INSET programmes were intended to assist with the improvement of science teaching in terms of the new curricula suggested for the country. The study proceeds by way of two case studies within an interpretive paradigm. The purpose of the study is to evaluate the two programmes based on the criteria developed through a literature review and to understand and give meaning to the process of teacher professional development that might have occurred in the programmes. This process is framed by my research question, “can resource kits enable professional development in science teaching”. Data was collected at various stages by way of field notes, questionnaires, interviews and observations at workshops. Teachers generally found the processes useful but do indicate dissatisfaction with certain areas of the programmes. Issues that emerged from the study were that teacher development processes need to be organized over a long period, the development of teacher networks needs to be nurtured, and support at school level was essential to ensure implementation. An important insight was that the research, once again, emphasized a key aspect of effective teacher development programmes. Effective programmes require a team consisting of three agents that bring their own expertise to the process namely, teachers, district officials and university staff. This team has to take into account the factors that ensure effective teacher professional development and should occur within the parameters of accepted professional development practices and learning support materials play an important role in supporting this process.

Les systèmes embarqués tels que les téléphones portables ou les lecteurs multimédia intègrent de plus en plus de fonctions consommatrices d'énergie ce qui a pour conséquence directe une diminution de leurs autonomies. Les applications audio dans les téléphones cellulaires et en particulier l'application casque font partie des fonctions les plus consommatrices d'énergie. Après un état de l'art des solutions permettant l'amplification de signaux audio, l'amplificateur de classe G à été identifié comme étant le meilleur candidat pour obtenir une amélioration du rendement tout en fournissant une bonne qualité de reproduction sonore. Nos travaux se sont plus particulièrement focalisés sur la détection d'enveloppe de ces architectures qui est un facteur clé dans la maximisation du rendement. Une étude des propriétés temporelles, fréquentielles et statistiques des signaux présents en entrée de l'amplificateur a ainsi été menée pour mettre en évidence les différences entre les signaux classiquement utilisés (signal sinusoïdal) et les signaux réellement écoutés par les utilisateurs (musique). Après avoir effectué une sélection de signaux pour la suite de notre étude, nous avons également caractérisé la puissance correspondant à des conditions normales d'écoute afin d'obtenir par la suite un environnement de test proche des conditions réelles de fonctionnement. Un modèle simplifié et rapide d'amplificateur hybride permettant d'obtenir en quelques dizaines de secondes, l'évaluation du rendement, de la consommation et de la qualité sonore dans des conditions réelles de fonctionnement a été développé. Notre modèle, entièrement configurable et réadaptable à d'autres types de circuits a été validé par mesures pratiques des performances d'un amplificateur existant. Les paramètres de la détection d'enveloppe de ce modèle ont fait l'objet d'une optimisation basée sur le couplage séquentiel de deux algorithmes d'optimisation, permettant ainsi dans un temps limité d'obtenir une solution optimale sans solution de départ sous des conditions réelles d'utilisation. La suite de notre étude nous a conduit à étudier, modéliser, optimiser et comparer des amplificateurs de classe G possédant un nombre de tensions d'alimentation supérieur (3, 4) ainsi que des amplificateurs de classe H (alimentations continues) afin d'améliorer encore le rendement. Enfin, nous avons proposé une nouvelle détection d'enveloppe permettant d'améliorer le rendement à faible puissance. Cette nouvelle détection d'enveloppe permet à l'amplificateur de classe G un fonctionnement en « multi niveau » et d'être auto adaptatif au signal audio présent en entrée de l'amplificateur. Après avoir développé des méta-modèles pour optimiser les paramètres de la détection d'enveloppe, cette détection d'enveloppe a été implémentée au niveau transistor en technologie 0.25μm de ST Microelectronics. / Embedded systems such as mobile phones, tablets and GPS incorporate an increasing number of electronic functions that generate a decrease in battery life. The aim of this work is to propose new solutions for audio amplifiers for the headphone application because this application has a large impact on battery autonomy. To improve the efficiency of actual amplifiers, a behavioral model of this kind of amplifier has been developed and validated by practical measures. This model, fast, accurate and reconfigurable allows in few seconds to evaluate the efficiency, consumption and quality of sound reproduction in real conditions of operation. Through the use of this model coupled with an optimizing method based on two algorithms, several architectures of level detector were studied and compared allowing to define the best compromise. A new architecture is then proposed, simulated and optimized in a 0.25μm technology from ST Microelectronics to demonstrate the feasibility of the solution.

A dissertação trata da construção da municipalização do licenciamento ambiental de Porto Alegre, realizado no âmbito da ampliação das formas de participação na cidade, conhecida como democracia participativa. A questão que a pesquisa enfrentou é se a hierarquia dos processos de globalização em relação aos governos municipais (global/local) limita esses à produção de políticas públicas destinadas a melhor posicionar as cidades à lógica dos fluxos necessários ao mercado, ou podem construir alternativas capazes de valer-se das possibilidades abertas e colocá-las a serviço da lógica da cidadania. A pesquisa identificou que a experiência de participação social na gestão pública em Porto Alegre – reconhecida mundialmente – permitiu inovações institucionais, como induzir ao consorciamento das empresas de telecomunicações e a criação de uma empresa pública na área, a “Infovia Porto Alegre”; além de tornar a cidade referência para vasta rede alternativa à globalização hegemônica. / This thesis deals with the municipalization of environmental licensing in Porto Alegre carried out in what is known as participative democracy, an amplification of the forms of participation in the city. The question placed by this research is if the hierarchy of the processes of globalization in regards to municipal administrations (global/local) limits these processes to the creation of public policies which aim at improving the positions of cities in light of the necessary directions of the market; or if they enable the construction of alternatives that can make use of the possibilities that are open and place themselves at the service of the logic of citizenship. The research found that the world renowned experience of social participation in Porto Alegre’s public administration allowed institutional innovations, such as encouraging the consortium of telecommunication companies and the creation of a public enterprise in this area, the “Infovia Porto Alegre”; besides making the city a reference for a vast alternative to hegemonic globalization.

A dissertação trata da construção da municipalização do licenciamento ambiental de Porto Alegre, realizado no âmbito da ampliação das formas de participação na cidade, conhecida como democracia participativa. A questão que a pesquisa enfrentou é se a hierarquia dos processos de globalização em relação aos governos municipais (global/local) limita esses à produção de políticas públicas destinadas a melhor posicionar as cidades à lógica dos fluxos necessários ao mercado, ou podem construir alternativas capazes de valer-se das possibilidades abertas e colocá-las a serviço da lógica da cidadania. A pesquisa identificou que a experiência de participação social na gestão pública em Porto Alegre – reconhecida mundialmente – permitiu inovações institucionais, como induzir ao consorciamento das empresas de telecomunicações e a criação de uma empresa pública na área, a “Infovia Porto Alegre”; além de tornar a cidade referência para vasta rede alternativa à globalização hegemônica. / This thesis deals with the municipalization of environmental licensing in Porto Alegre carried out in what is known as participative democracy, an amplification of the forms of participation in the city. The question placed by this research is if the hierarchy of the processes of globalization in regards to municipal administrations (global/local) limits these processes to the creation of public policies which aim at improving the positions of cities in light of the necessary directions of the market; or if they enable the construction of alternatives that can make use of the possibilities that are open and place themselves at the service of the logic of citizenship. The research found that the world renowned experience of social participation in Porto Alegre’s public administration allowed institutional innovations, such as encouraging the consortium of telecommunication companies and the creation of a public enterprise in this area, the “Infovia Porto Alegre”; besides making the city a reference for a vast alternative to hegemonic globalization.