• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 105
  • 32
  • 11
  • 9
  • 5
  • 4
  • 4
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 229
  • 44
  • 42
  • 39
  • 38
  • 19
  • 18
  • 17
  • 16
  • 12
  • 12
  • 11
  • 11
  • 11
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Telefonia por banda larga e satisfaçao do usuario: estudo com os clientes do velox em salvador

Oliveira, Carlos Magno Neves de January 2006 (has links)
p. 1-110 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-03-07T19:10:39Z No. of bitstreams: 1 88888q.pdf: 1473667 bytes, checksum: 7db700f83e8b6688927f7d2e24326d50 (MD5) / Approved for entry into archive by Tatiana Lima(tatianasl@ufba.br) on 2013-03-13T18:47:29Z (GMT) No. of bitstreams: 1 88888q.pdf: 1473667 bytes, checksum: 7db700f83e8b6688927f7d2e24326d50 (MD5) / Made available in DSpace on 2013-03-13T18:47:29Z (GMT). No. of bitstreams: 1 88888q.pdf: 1473667 bytes, checksum: 7db700f83e8b6688927f7d2e24326d50 (MD5) Previous issue date: 2006 / Atualmente, a investigação sobre a satisfação dos clientes em serviços tem tido grande destaque, tanto no meio acadêmico quanto empresarial. Inúmeras pesquisas revelam a importância desses estudos para o desenvolvimento e o crescimento das empresas. Esta pesquisa investigou a satisfação do cliente de telefonia por banda larga (Velox) da Telemar, em Salvador, nos bairros que mais utilizam esse serviço. Através da aplicação de um roteiro de entrevistas semi-estruturado, buscamos identificar a satisfação do cliente em relação às principais dimensões do serviço, a saber: (1) desempenho do serviço; (2) relação custo-benefício, (3) central de atendimento; (4) reparo técnico. A pesquisa verificou ainda que, de maneira geral, a satisfação do cliente com o serviço de banda larga da Telemar pode ser considerada muito boa. Em todas as dimensões, exceto a relação custo - benefício, a maioria dos clientes se declarou bastante satisfeita. / Salvador
152

Bioecologia de Polyphagotarsonemus latus em acessos de pinhão manso (Jatropha curcas) / Bioecology of Polyphagotarsonemus latus in genotypes of physic nut(Jatropha curcas)

Lopes, Elisângela Novais 31 July 2009 (has links)
Made available in DSpace on 2015-03-26T13:30:27Z (GMT). No. of bitstreams: 1 texto completo.pdf: 568529 bytes, checksum: 57591390719fc6e83e520999363ba837 (MD5) Previous issue date: 2009-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The broad mite Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) has been cited as one of the most important pests of physic nut in Brazil. However, there is no information available about broad mite development on the main genotypes of physic nut cultivated in Brazil. Besides, the control of P. latus has been done with synthetic acaricides, without the knowledge of broad mite densities, due to the lack of sampling plans for the pest in this crop. The aims of this research were to study the biological parameters of P. latus and its population growth on physic nut genotypes, the predators associated to broad mite in physic nut genotypes, and to determine a sampling plan for P. latus. The informations were distributed in three chapters. In Chapter 1, it was evaluated P. latus biology and its population growth through the estimation of the intrinsic rate of population increase (rm) in laboratory and the instantaneous rate of population increase (ri) in the greenhouse, on five physic nut genotypes (Filomena, Bento, Oracília, Gonçalo and Paraguaçú). In Chapter 2 , we determined the unit amostral, the amostral technique and the more representative number of samples to compose the sampling plan of P. latus in physic nut plants. In the chapter 3, it was studied the population dynamics of P. latus in the field, in nine genotypes of physic nut, their attack seasonality, the importance of the predatory mites in controlling P. latus population. P. latus was capable to complete its life cycle and to reproduce in the tested genotypes. The biological parameters and the fecundity of P. latus didi not differ among the tested physic nut genotypes. The intrinsic rate of population increase (rm) and the instantaneous rate of population increase (ri) were similar among the genotypes. The injury levels of P. latus didn't differ among the genotypes. For the sampling plan, the leaf surface selected for the sampling of P. latus in physic nut was the abaxial and the ideal positions for sampling are those close to the petioles (P5 and P6) of that surface. The direct counting with aid of manual magnifying glass was the best sampling technique. The most representative leaves for broad mite sampling were from the 2nd to 4th leaf. Adjustment was not observed of the sample data the any frequency distribution, however the number of samples to compose the sampling plan was 79 samples/farming, what requests 0.95 hours/sampling and costs R$ 17.67 for the sampling. In the field, the levels of infestation of P. latus along the time andthe number of predatory mites didn't vary among the physic nut genotypes. There was no significant correlation betweenthe predatory mite Iphiseiodes zuluagai and P. latus populations, however there was a positive correlation among predatori mites Typhlodromalus spp., the climatic factors (precipitation, temperature and photoperiod) and the densities of P. latus. The population peak of P. latus was during November and December. / O ácaro branco Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae) tem sido relatado como uma das pragas mais importantes do pinhão manso Jatropha curcas L. no Brasil. No entanto, não existem informações sobre o potencial de desenvolvimento desta praga nos principais acessos de pinhão manso plantados no território nacional. Além disso, o controle de P. latus tem sido realizado utilizando-se acaricidas, sem o conhecimento das densidades populacionais, devido à inexistência de um sistema amostral desenvolvido em plantas de pinhão manso para esta praga.Assim nesse trabalho se propõe estudar os parâmetros biológicos de P. latus, seu potencial de crescimento populacional em acessos de pinhão manso, a susceptibilidade de acessos de pinhão manso a P. latus, os ácaros predadores e ainda determinar um plano de amostragem para P. latus neste hospedeiro. As informações obtidas foram distribuídas em três capítulos. No Capítulo 1, avaliou-se a biologia de P. latus e seu potencial de crescimento através da taxa intrínseca de crescimento populacional (rm) em laboratório e da taxa instantânea de crescimento populacional (ri) e as injúrias causadas pelo ácaro em casa de vegetação nos acessos de pinhão manso Filomena, Bento, Oracília, Gonçalo e Paraguaçú. No capítulo 2 determinaram-se a unidade amostral, a técnica amostral e o número de amostras mais representativos para compor o plano de amostragem de P. latus em plantas de pinhão manso. No capítulo 3, foi estudada a dinâmica populacional de P. latus em campo, em nove acessos de pinhão manso, com o intuito de conhecer as diferenças na infestação nos acessos, a sazonalidade do ataque e a importância dos ácaros predadores. P. latus foi capaz de completar seu ciclo e se reproduzir nos acessos Filomena, Bento, Gonçalo, Oracília e Paraguaçú. Não foi detectada diferença significativa na duração dos parâmetros biológicos e na fecundidade de P. latus entre os acessos de pinhão manso. As taxas de crescimento populacional em laboratório (rm) e em casa de vegetação (ri) foram semelhantes entre os acessos de pinhão manso. Os níveis de injúria de P. latus não diferiram entre os acessos de pinhão manso. Quanto ao plano de amostragem, a face da folha selecionada para a amostragem de P. latus em pinhão manso foi a abaxial e as posições ideais para amostragem são próximas ao pecíolo (P5 e P6) desta face. A contagem direta com lupa manual foi a melhor técnica amostral. As folhas mais representativas para amostragem de P. latus foram da 2ª a 4ª folha. Não foi observado ajuste dos dados amostrais a nenhuma distribuição de frequência, porém o número de amostras determinado para compor o plano de amostragem foi 79 amostras/lavoura, o que requer um tempo de 0,95 horas/amostragem e um custo de R$ 17,67 para a amostragem. No campo, os níveis de infestação de P. latus ao longo do tempo e o número de ácaros predadores não variaram entre os acessos de pinhão manso. Não foi observada correlação significativa entre os ácaros predadores da espécie Iphiseiodes zuluagai e as populações de P. latus, porém houve correlação positiva entre ácaros predadores Typhlodromalus spp., os fatores climáticos (precipitação, temperatura e fotoperíodo) e as densidades de P. latus em campo. O pico populacional de P. latus ocorreu nos meses de novembro e dezembro.
153

A narrativa na e sobre a clínica na atenção primária: uma reflexão sobre o modo pensar e agir dirigido ao diálogo, à integralidade e ao cuidado em saúde / The narrative in and about the clinic in primary care: a reflection on how to think and act directed dialogue, completeness and health care

César Augusto Orazem Favoreto 03 October 2007 (has links)
A incorporação do sujeito que adoece e suas expectativas de cuidado é um apelo que acompanha as propostas de mudança da prática clínica no campo da APS. Esta perspectiva implica em um novo modo de ver o processo de adoecimento que procura romper com o reducionismo biomédico onde a clínica e sua ação são, praticamente, independentes do discurso do paciente. Este trabalho usou a narrativa, aplicada como uma ferramenta conceitual e prática na clínica na APS, para investigar as possibilidades de ampliar o universo discursivo e interpretativo, isto é, a competência narrativa do médico, para além de um modelo biomédico restritivo. Foi realizada uma busca, não sistemática, na literatura médica e de ciências sociais procurando identificar os aspectos conceituais, significados e perspectivas que podem ser assumidos para substantivar a narrativa como um conceito/idéia e suas possíveis interfaces e aplicações na clínica. Esta apropriação da narrativa instrumentalizou a observação participante nos módulos do Programa Médico de Família de Niterói, assim como a realização e análise dos resultados de entrevistas semi-estruturadas com seus médicos. Observou-se que a formação da identidade e da legitimidade profissionais do médico de família é dirigida, principalmente, pelo arranjo organizacional promovido pelo modelo de atenção e não pelo desenvolvimento de um saber que o diferencie e qualifique. Identificou-se que as capacidades dialógicas desenvolvidas nas experiências com a clínica na APS eram compreendidas e assumidas pelos médicos como habilidades pessoais e/ou como aspectos morais. Percebeu-se que este modo de pensar dá margem a uma tensão, externada por um discurso ambíguo e fragmentado, entre a proximidade, o vínculo e o diálogo com o paciente e a estruturação do saber e da prática clínica. A limitação dos médicos em incorporar novos saberes a partir de suas vivências, associada à forma como a racionalidade biomédica dirige a clínica, se constituem como obstáculos epistemológicos e práticos para a ampliação da competência narrativa e interpretativa médica. Estas são condições que dificultam o desenvolvimento de um estilo de pensamento médico que reflita, desenvolva e integre o saber prático e os saberes não biomédicos como algo legítimo, sistematizável, avaliável e reprodutível no âmbito da clínica. / The incorporation of the fellow who falls ill and his expectations of care is an appeal of the proposals to change primary care clinical practices. This perspective implies a new viewpoint of the sickening process which tries to break with the biomedical reductionism in which the clinic and its action are almost apart of the patients discourse. This work employed the narrative as a conceptual and practical tool in primary care clinic to investigate the possibilities of enlarging the universe of discourse and interpretation, that is, the physicians narrative competence beyond a restrictive biomedical model. A non- systematic search was carried out, in medical and social sciences literature, trying to identify the conceptual aspects, meanings and perspectives that can be assumed to turn the narrative into a concept/idea, and its possible interfaces and applications to clinic. This appropriation of narrative instrumentalized the participant observation in the Family Health Program, in Niterói, as well as the analysis of results of semi-structured interviews with physicians. We noticed that the formation of the family doctors professional identity and legitimacy is mostly guided by the organization promoted by the healthcare model, and not by the development of knowledge able to distinguish and qualify it. We found that the dialogic abilities developed in experiences in primary care clinic were apprehended and assumed by physicians as personal abilities and/or moral aspects. This thought created tension, translated in an ambiguous and fragmented discourse among proximity, liaison and dialogue with patients, and the formation of knowledge and clinical practice. The physicians limitations to incorporate new knowledge, based on their own experience, and the way biomedical rationality guides clinic, are epistemological and practical obstacles to enlarge medical narrative and interpretative competences. Such conditions hinder the development of a type of medical thought to reflect, develop and integrate practical knowledge and nonbiomedical knowledge as legitimate, able to be systematized, evaluated and reproduced within the clinic.
154

Conception d'antenne intelligente reconfigurable pour la radio cognitive / Design of an reconfigurable smart antenna for cognitive radio

Nguyen, Trong Duc 24 October 2012 (has links)
Les antennes reconfigurables offrent de multiples fonctions en changeant dynamiquement leurs propriétés telles que la fréquence de fonctionnement, la polarisation, le diagramme de rayonnement ou toute combinaison de ces trois paramètres. Leur agilité et leur diversité créent de nouvelles possibilités d'applications pour les systèmes radio tels que les réseaux locaux, les liaisons par satellite et notamment la radio cognitive. Dans cette thèse, deux antennes reconfigurables en fréquence fonctionnant dans les bandes des standards sans fil actuels ont été proposées. Elles sont basées sur la modification de la géométrie du patch rayonnant. Leurs dimensions ont été optimisées par algorithmes génétiques embarqués et combinés à un logiciel de simulation électromagnétique. La commande de la reconfiguration de ces antennes est réalisée à l'aide d'un microcontrôleur qui pilote l'état des commutateurs (des diodes PIN). De ce fait, un système d'antenne reconfigurable intelligent dédié à la radio cognitive a été développé. / Reconfigurable antennas offer multiple functions by dynamically changing their properties such as operating frequency, polarization, radiation pattern, and a combination of all these factors. Their agility and diversity create a wide range of different and new applications for radio systems such as local networks, satellites, and especially in cognitive radio. In this thesis, two new frequency reconfigurable antennas are proposed. The frequency reconfiguration is obtained by changing the geometry of radiating patch. Their dimensions have been optimized by genetic algorithm embedded in the electromagnetic simulation software. These antennas operate at the frequency band for IEEE 802.11b/g standard with satisfactory radiation characteristics. This thesis also presents a method of controlling the operation of the frequency reconfigurable antenna by a micro-controller. The operation of electronic switches (PIN diodes) are carried out through programs which allows an adaptive operating system like smart antennas and work well in cognitive radio environment.
155

A narrativa na e sobre a clínica na atenção primária: uma reflexão sobre o modo pensar e agir dirigido ao diálogo, à integralidade e ao cuidado em saúde / The narrative in and about the clinic in primary care: a reflection on how to think and act directed dialogue, completeness and health care

César Augusto Orazem Favoreto 03 October 2007 (has links)
A incorporação do sujeito que adoece e suas expectativas de cuidado é um apelo que acompanha as propostas de mudança da prática clínica no campo da APS. Esta perspectiva implica em um novo modo de ver o processo de adoecimento que procura romper com o reducionismo biomédico onde a clínica e sua ação são, praticamente, independentes do discurso do paciente. Este trabalho usou a narrativa, aplicada como uma ferramenta conceitual e prática na clínica na APS, para investigar as possibilidades de ampliar o universo discursivo e interpretativo, isto é, a competência narrativa do médico, para além de um modelo biomédico restritivo. Foi realizada uma busca, não sistemática, na literatura médica e de ciências sociais procurando identificar os aspectos conceituais, significados e perspectivas que podem ser assumidos para substantivar a narrativa como um conceito/idéia e suas possíveis interfaces e aplicações na clínica. Esta apropriação da narrativa instrumentalizou a observação participante nos módulos do Programa Médico de Família de Niterói, assim como a realização e análise dos resultados de entrevistas semi-estruturadas com seus médicos. Observou-se que a formação da identidade e da legitimidade profissionais do médico de família é dirigida, principalmente, pelo arranjo organizacional promovido pelo modelo de atenção e não pelo desenvolvimento de um saber que o diferencie e qualifique. Identificou-se que as capacidades dialógicas desenvolvidas nas experiências com a clínica na APS eram compreendidas e assumidas pelos médicos como habilidades pessoais e/ou como aspectos morais. Percebeu-se que este modo de pensar dá margem a uma tensão, externada por um discurso ambíguo e fragmentado, entre a proximidade, o vínculo e o diálogo com o paciente e a estruturação do saber e da prática clínica. A limitação dos médicos em incorporar novos saberes a partir de suas vivências, associada à forma como a racionalidade biomédica dirige a clínica, se constituem como obstáculos epistemológicos e práticos para a ampliação da competência narrativa e interpretativa médica. Estas são condições que dificultam o desenvolvimento de um estilo de pensamento médico que reflita, desenvolva e integre o saber prático e os saberes não biomédicos como algo legítimo, sistematizável, avaliável e reprodutível no âmbito da clínica. / The incorporation of the fellow who falls ill and his expectations of care is an appeal of the proposals to change primary care clinical practices. This perspective implies a new viewpoint of the sickening process which tries to break with the biomedical reductionism in which the clinic and its action are almost apart of the patients discourse. This work employed the narrative as a conceptual and practical tool in primary care clinic to investigate the possibilities of enlarging the universe of discourse and interpretation, that is, the physicians narrative competence beyond a restrictive biomedical model. A non- systematic search was carried out, in medical and social sciences literature, trying to identify the conceptual aspects, meanings and perspectives that can be assumed to turn the narrative into a concept/idea, and its possible interfaces and applications to clinic. This appropriation of narrative instrumentalized the participant observation in the Family Health Program, in Niterói, as well as the analysis of results of semi-structured interviews with physicians. We noticed that the formation of the family doctors professional identity and legitimacy is mostly guided by the organization promoted by the healthcare model, and not by the development of knowledge able to distinguish and qualify it. We found that the dialogic abilities developed in experiences in primary care clinic were apprehended and assumed by physicians as personal abilities and/or moral aspects. This thought created tension, translated in an ambiguous and fragmented discourse among proximity, liaison and dialogue with patients, and the formation of knowledge and clinical practice. The physicians limitations to incorporate new knowledge, based on their own experience, and the way biomedical rationality guides clinic, are epistemological and practical obstacles to enlarge medical narrative and interpretative competences. Such conditions hinder the development of a type of medical thought to reflect, develop and integrate practical knowledge and nonbiomedical knowledge as legitimate, able to be systematized, evaluated and reproduced within the clinic.
156

Applicabilité de la PCR "universelle" 16S comme outil d'identification et de détection bactérienne en laboratoire hospitalier de bactériologie

Renvoisé, Aurélie 02 July 2012 (has links)
La PCR universelle ciblant le gène codant pour l'ARNr 16S à l'aide d'amorces universelles, a d'abord été développée pour des études phylogénétiques. En effet ce gène est universellement retrouvé chez les bactéries et sa fonction est conservée. Ainsi, il peut servir d'« horloge moléculaire » pour mesurer les distances phylogénétiques entre les différentes espèces bactériennes. La PCR universelle a ensuite été appliquée en microbiologie clinique dans deux domaines distincts : la détection et l'identification bactériennes. Dans ce travail, nous avons évalué l'applicabilité de la PCR « universelle » 16S comme outil diagnostique dans un centre hospitalier universitaire (hôpital la Timone, Marseille, France). Tout d'abord, nous avons décrit comment la PCR universelle permet l'identification de souches bactériennes mal identifiées par les techniques phénotypiques conventionnelles. Puis, nous avons montré que la PCR universelle peut être utilisée pour détecter l'ADN bactérien dans des prélèvements à culture négative, soit parce que le patient a reçu une antibiothérapie préalable, soit parce que le microorganisme responsable est de croissance difficile. Enfin, nous avons montré que la PCR 16S utilisée pour l'identification permet de mettre en évidence des souches susceptibles de représenter de nouvelles espèces et/ou de nouveaux genres bactériens. Ainsi, la PCR universelle est applicable dans un laboratoire de bactériologie de routine dans les trois objectifs ci-dessus. Elle permet une identification précise des souches bactériennes et l'amélioration du diagnostic des infections associées à des cultures négatives et, par là-même, l'amélioration de la prise en charge des patients. / Broad-range 16S rDNA PCR using universal primers was first developed for phylogenetic purpose since 16S rRNA gene is found in every bacterial species with a conserved function; consequently 16S rRNA gene can be used as a molecular clock for assessing bacterial phylogeny. Broad-range PCR was then applied to medical microbiological diagnosis in two distinct fields: molecular detection and bacteria identification. In the present work, we evaluated the applicability of broad-range PCR as a diagnostic tool in a teaching hospital (Timone Hospital, Marseilles, France). First, we showed that broad-range PCR allows identification of bacteria obtained in culture but misidentified by conventional phenotypic methods. Second, we showed that universal PCR permits bacterial detection in culture-negative infection. Third, we exemplified that using broad-range PCR is a valuable tool to identify new bacterial species and/or genera. Consequently, universal PCR is applicable in routine laboratories in the three above fields; it allows a more accurate identification of bacterial strains and permits to diagnose culture-negative bacterial infections, thus improving patient's management. It also improves our knowledge of infectious diseases together with bacterial diversity and phylogeny. Although universal PCR presents certain limitations (discussed in this work), it remains today the gold-standard for molecular identification and detection in routine laboratories.
157

Aarhuská úmluva v judikatuře Soudního dvora Evropské unie. / The Aarhus convention in the Case law of Court of Justice of European Union

Opočenský, Marek January 2016 (has links)
This thesis describes issues which occurring during the implementation of requirements of Aarhus convention. The Convention has unique character, as it combines the basic human rights with environmental rights. Since 2005 The European Union is signatory, which means that content of Convention is part of union law and falls within the jurisdiction of the Court of Justice of European Union. The first chapter deals with the particular elements of the Aarhus convention. In the chapter two are described the consequences of accession to the Convention for European Union and her member states. The core of this thesis consists of chapters, 3-5, which in sequence analyzes, through selected court decisions, the most complicated provisions from the perspective of implementation and suggest certain tendencies in decision-making of the Court of Justice of The European Union. Among the most obvious belong differential treatment and claims on European and domestic bodies in executing the rights guaranteed by Aarhus convention. The final chapter suggests the overlap to the Czech regulation, concretely alerts at changes in decision-making and the legislature, which are among others strongly inspired by judgments of the CJ EU.
158

Multilevel model reduction for uncertainty quantification in computational structural dynamics / Réduction de modèle multi-niveau pour la quantification des incertitudes en dynamique numérique des structures

Ezvan, Olivier 23 September 2016 (has links)
Ce travail de recherche présente une extension de la construction classique des modèles réduits (ROMs) obtenus par analyse modale, en dynamique numérique des structures linéaires. Cette extension est basée sur une stratégie de projection multi-niveau, pour l'analyse dynamique des structures complexes en présence d'incertitudes. De nos jours, il est admis qu'en dynamique des structures, la prévision sur une large bande de fréquence obtenue à l'aide d'un modèle éléments finis doit être améliorée en tenant compte des incertitudes de modèle induites par les erreurs de modélisation, dont le rôle croît avec la fréquence. Dans un tel contexte, l'approche probabiliste non-paramétrique des incertitudes est utilisée, laquelle requiert l'introduction d'un ROM. Par conséquent, ces deux aspects, évolution fréquentielle des niveaux d'incertitudes et réduction de modèle, nous conduisent à considérer le développement d'un ROM multi-niveau, pour lequel les niveaux d'incertitudes dans chaque partie de la bande de fréquence peuvent être adaptés. Dans cette thèse, on s'intéresse à l'analyse dynamique de structures complexes caractérisées par la présence de plusieurs niveaux structuraux, par exemple avec un squelette rigide qui supporte diverses sous-parties flexibles. Pour de telles structures, il est possible d'avoir, en plus des modes élastiques habituels dont les déplacements associés au squelette sont globaux, l'apparition de nombreux modes élastiques locaux, qui correspondent à des vibrations prédominantes des sous-parties flexibles. Pour ces structures complexes, la densité modale est susceptible d'augmenter fortement dès les basses fréquences (BF), conduisant, via la méthode d'analyse modale, à des ROMs de grande dimension (avec potentiellement des milliers de modes élastiques en BF). De plus, de tels ROMs peuvent manquer de robustesse vis-à-vis des incertitudes, en raison des nombreux déplacements locaux qui sont très sensibles aux incertitudes. Il convient de noter qu'au contraire des déplacements globaux de grande longueur d'onde caractérisant la bande BF, les déplacements locaux associés aux sous-parties flexibles de la structure, qui peuvent alors apparaître dès la bande BF, sont caractérisés par de courtes longueurs d'onde, similairement au comportement dans la bande hautes fréquences (HF). Par conséquent, pour les structures complexes considérées, les trois régimes vibratoires BF, MF et HF se recouvrent, et de nombreux modes élastiques locaux sont entremêlés avec les modes élastiques globaux habituels. Cela implique deux difficultés majeures, concernant la quantification des incertitudes d'une part et le coût numérique d'autre part. L'objectif de cette thèse est alors double. Premièrement, fournir un ROM stochastique multi-niveau qui est capable de rendre compte de la variabilité hétérogène introduite par le recouvrement des trois régimes vibratoires. Deuxièmement, fournir un ROM prédictif de dimension réduite par rapport à celui de l'analyse modale. Une méthode générale est présentée pour la construction d'un ROM multi-niveau, basée sur trois bases réduites (ROBs) dont les déplacements correspondent à l'un ou l'autre des régimes vibratoires BF, MF ou HF (associés à des déplacements de type BF, de type MF ou bien de type HF). Ces ROBs sont obtenues via une méthode de filtrage utilisant des fonctions de forme globales pour l'énergie cinétique (par opposition aux fonctions de forme locales des éléments finis). L'implémentation de l'approche probabiliste non-paramétrique dans le ROM multi-niveau permet d'obtenir un ROM stochastique multi-niveau avec lequel il est possible d'attribuer un niveau d'incertitude spécifique à chaque ROB. L'application présentée est relative à une automobile, pour laquelle le ROM stochastique multi-niveau est identifié par rapport à des mesures expérimentales. Le ROM proposé permet d'obtenir une dimension réduite ainsi qu'une prévision améliorée, en comparaison avec un ROM stochastique classique / This work deals with an extension of the classical construction of reduced-order models (ROMs) that are obtained through modal analysis in computational linear structural dynamics. It is based on a multilevel projection strategy and devoted to complex structures with uncertainties. Nowadays, it is well recognized that the predictions in structural dynamics over a broad frequency band by using a finite element model must be improved in taking into account the model uncertainties induced by the modeling errors, for which the role increases with the frequency. In such a framework, the nonparametric probabilistic approach of uncertainties is used, which requires the introduction of a ROM. Consequently, these two aspects, frequency-evolution of the uncertainties and reduced-order modeling, lead us to consider the development of a multilevel ROM in computational structural dynamics, which has the capability to adapt the level of uncertainties to each part of the frequency band. In this thesis, we are interested in the dynamical analysis of complex structures in a broad frequency band. By complex structure is intended a structure with complex geometry, constituted of heterogeneous materials and more specifically, characterized by the presence of several structural levels, for instance, a structure that is made up of a stiff main part embedding various flexible sub-parts. For such structures, it is possible having, in addition to the usual global-displacements elastic modes associated with the stiff skeleton, the apparition of numerous local elastic modes, which correspond to predominant vibrations of the flexible sub-parts. For such complex structures, the modal density may substantially increase as soon as low frequencies, leading to high-dimension ROMs with the modal analysis method (with potentially thousands of elastic modes in low frequencies). In addition, such ROMs may suffer from a lack of robustness with respect to uncertainty, because of the presence of the numerous local displacements, which are known to be very sensitive to uncertainties. It should be noted that in contrast to the usual long-wavelength global displacements of the low-frequency (LF) band, the local displacements associated with the structural sub-levels, which can then also appear in the LF band, are characterized by short wavelengths, similarly to high-frequency (HF) displacements. As a result, for the complex structures considered, there is an overlap of the three vibration regimes, LF, MF, and HF, and numerous local elastic modes are intertwined with the usual global elastic modes. This implies two major difficulties, pertaining to uncertainty quantification and to computational efficiency. The objective of this thesis is thus double. First, to provide a multilevel stochastic ROM that is able to take into account the heterogeneous variability introduced by the overlap of the three vibration regimes. Second, to provide a predictive ROM whose dimension is decreased with respect to the classical ROM of the modal analysis method. A general method is presented for the construction of a multilevel ROM, based on three orthogonal reduced-order bases (ROBs) whose displacements are either LF-, MF-, or HF-type displacements (associated with the overlapping LF, MF, and HF vibration regimes). The construction of these ROBs relies on a filtering strategy that is based on the introduction of global shape functions for the kinetic energy (in contrast to the local shape functions of the finite elements). Implementing the nonparametric probabilistic approach in the multilevel ROM allows each type of displacements to be affected by a particular level of uncertainties. The method is applied to a car, for which the multilevel stochastic ROM is identified with respect to experiments, solving a statistical inverse problem. The proposed ROM allows for obtaining a decreased dimension as well as an improved prediction with respect to a classical stochastic ROM
159

The monitoring and evaluation framework for the broad based black economic empowerment policy in South Africa and lessons of experience for Namibia

Kasuto, Okasute Akwega January 2009 (has links)
Masters in Public Administration - MPA / The Namibian Government has recently embarked on the formulation of an empowerment strategy similar to South Africa’s Broad Based Black Economic Empowerment (BBBEE) policy - the Transformation of Economic and Social Empowerment Framework (TESEF) for Namibia. Monitoring and evaluation (M&E) more specifically, results-based M&E has also recently emerged worldwide as an important tool in public sector management reform and is focused on the attainment of outcomes and development results at project, programme and policy levels. The problem being investigated in this study concerns the shortage of evidence in BBBEE policy and legislative documentation of a coherent M&E framework inclusive of a set of indicators that can measure BBBEE progress against its set objectives and anticipated outcomes.Through an investigation on the state of an M&E framework for BBBEE and South Africa’s good experiences regarding the development of a Government-wide (including all sectors) coherent M&E system a number of lessons of experience have been drawn for the anticipated implementation and M&E framework of TESEF and the establishment of a Government-wide M&E system in Namibia.The study reveals that there is currently (May 2009) no comprehensive M&E framework inclusive of set of indicators in effect to measure BBBEE progress towards its objectives and anticipated outcomes. The suitability of available indicators to measure BBBEE derived from the South African Development Indicator framework (SADI) and the Compendium of Indicators for the Provincial Growth and Development Strategy (CIPGDS) of the Western Cape are assessed and the potential for indicator development has been explored. Through an appropriate methodology a comprehensive set of indicators that address the objectives and anticipated outcomes of BBBEE are developed and suggested in this study.The study found that while Namibia sees herself in the final phase of TESEF formulation with the release of the latest TESEF Draft Strategy Document (April 2008) the country also sets out plans in its National Development Plan (NDP3) for period 2007/08 –2011/12 for the establishment and institutionalisation of a government-wide M&E system dedicated to the results-based M&E approach. The study finds valuable lessons for Namibia in South Africa’s Government-wide M&E (GWM&E) system drawn from South Africa’s development of: a Policy Framework for GWM&E system; a comprehensive set of national development indicators across prioritised clusters (the South African Development Indicator framework); and the established public sector capacity building and M&E support organs such as the Public Administration Leadership and Management Academy (PALAMA) formerly known the South African Management Development Institute (SAMDI) and the South African Monitoring and Evaluation Association (SAMEA).Apart from the potential indicators to measure BBBEE developed as part of the study’s recommendations, the study also recommends that an M&E framework for TESEF is developed upon finalization of the policy’s objectives and anticipated outcomes and that this framework is included in the final TESEF design to guide its effective implementation.
160

Novel applications of optical analytical techniques

Seetohul, L. Nitin January 2009 (has links)
Novel applications of optical analytical techniques have been demonstrated in three general areas, namely application of broadband cavity enhanced absorption spectroscopy (BBCEAS) to the detection of liquid phase analytes, the use of total luminescence spectroscopy to discriminate between different type of teas and the development of an optical sensor to detect ammonia gas, based on the fluorescence quenching of a dye immobilised in a sol gel matrix. A simple BBCEAS setup has been developed with a view to perform sensitive visible wavelength measurements on liquid phase solutions. In the present work a simple low-cost experimental setup has been demonstrated for the measurement of the visible spectra of representative liquid-phase analytes in a 2 mm quartz cuvette placed at normal incidence to the cavity mirrors. Measurements on Ho3+ and sudan black with a white LED and the R ≥ 0.99 mirrors covered a broad wavelength range (~250 nm) and represents the largest wavelength range covered to date in a single BBCEAS experiment. The sensitivity of the technique as determined by the best αmin value was 5.1 x 10-5 cm-1 and was obtained using the R ≥ 0.99 mirrors. The best limit of detection (LOD) for the strong absorber brilliant blue-R, was approximately 620 pM. The optical setup was then optimised for the application of BBCEAS detection to an HPLC system. A 1 cm pathlength HPLC cell with a nominal volume of 70 ml was used in this study. The cavity was formed by two R ≥ 0.99 plano-concave mirrors with a bandwidth of ~ 420 – 670 nm. Two analytes rhodamine 6G and rhodamine B were chosen for separation by HPLC, as they were chemically similar species with distinctive visible spectra and would co-elute in an isocratic separation. The lowest value of amin obtained was 1.9 x 10-5 cm-1. The most significant advantage of the HPLC-BBCEAS study over previous studies arose from the recording of the absorption spectrum over a range of wavelengths. It was demonstrated that the spectral data collected could be represented as a contour plot which was useful in visualising analytes which nearly co-eluted. The LOD values for the two analytes studied indicated that the developed HPLC-BBCEAS setup was between 54 and 77 times more sensitive than a commercial HPLC system. For improved sensitivity and lower detection limits the low cost BBCEAS setup was used with a significantly longer 20 cm pathlength cell where the mirrors were in direct contact with the liquid phase analyte. This also reduced interface losses. The experiments were carried out using both R ³ 0.99 and R ³ 0.999 mirrors. The lowest αmin value obtained in this study was 2.8 x 10-7 cm-1 which is the lowest reported value to date for a liquid phase measurement, making this study the most sensitive liquid phase absorption measurement reported. The lowest LOD recorded was 4.6 pM, and was obtained for methylene blue with the R ³ 0.999 mirrors. A novel application of total luminescence spectroscopy to discriminate between different types of teas objectively was also investigated. A pattern recognition technique based on principal component analysis (PCA) was applied to the data collected and resulted in discrimination between both geographically similar and dissimilar teas. This work has shown the potential of fluorescence spectroscopy to distinguish between seven types of teas from Africa, India, Sri Lanka and Japan. Geographically similar black teas from 15 different plantation estates in Sri Lanka were also studied. The visualisation technique allowed the separation of all 11 types of teas when the first two principal components were utilised. The final part of the thesis describes the development of an optical sensor for the detection of ammonia gas. The operation of the sensor depended on the fluorescence quenching of the dye 9 amino acridine hydrochloride (9 AAH) immobilised in a sol gel matrix. It was also shown that the sensor response was not affected by the presence of acidic gases such as HCl and SO2. The final version of the sensor made use of dual channel monitoring to improve the sensitivity of the sensor. Measurements using diluted mixtures of ammonia gas in the range 5 -70 ppm showed that the response of the sensor was nonlinear, with the sensitivity increasing at lower concentrations. The measurement of the baseline noise allowed the LOD to be estimated at ~400 ppb.

Page generated in 0.0524 seconds