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  • 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.
531

Integrated optical interferometric sensors on silicon and silicon cmos

Thomas, Mikkel Andrey 14 October 2008 (has links)
The main objective of this research is to fabricate and characterize an optically integrated interferometric sensor on standard silicon and silicon CMOS circuitry. An optical sensor system of this nature would provide the high sensitivity and immunity to electromagnetic interference found in interferometric based sensors in a lightweight, compact package capable of being deployed in a multitude of situations inappropriate for standard sensor configurations. There are several challenges involved in implementing this system. These include the development of a suitable optical emitter for the sensor system, the interface between the various optically embedded components, and the compatibility of the Si CMOS with heterogeneous integration techniques. The research reported outlines a process for integrating an integrated sensor on Si CMOS circuitry using CMOS compatible materials, integration techniques, and emitter components.
532

Microwave aerial and waveguide system for an airborne continuous-wave Doppler navigation equipment

Crompton, James Woodhouse. January 1900 (has links) (PDF)
Thesis, (M.E.?)-- University of Adelaide, Dept. of Engineering, 1958. / Typewritten.
533

Le développement de corpus annotés pour la langue arabe / Building annotated corpora for the Arabic language

Zaghouani, Wajdi 06 January 2015 (has links)
L’objectif de cette thèse est de montrer les différentes facettes de l’annotation de corpus dans la langue arabe. Nous présentons nos travaux scientifiques sur l’annotation de corpus et sur la création de ressources lexicales dans la langue arabe. D’abord, nous discutons des méthodes, des difficultés linguistiques, des guides d’annotation, de l’optimisation de l’effort d’annotation, ainsi que de l’adaptation à la langue arabe de procédures d’annotation existantes. Ensuite, nous montrons la complémentarité entre les différentes couches d’annotation. Enfin, nous illustrons l’importance de ces travaux pour le traitement automatique des langues en illustrant quelques exemples de ressources et d’applications. / The goal of this thesis is to show the various aspects of corpus annotation in the Arabic language. We present our publications on corpus annotation and lexical resources creation in the Arabic language. First, we discuss the methods, the language difficulties, the annotation guidelines, the annotation effort optimization limits and how we adapted some of the existing annotation procedures to the Arabic language. Furthermore, we show the complementarity between the different layers of annotations. Finally, we illustrate the importance of our work for natural language processing by illustrating some examples of resources and applications.
534

A educação de jovens e adultos por meio de roteiros de aprendizagem no ensino de química

Costa, Mauro Melo January 2017 (has links)
Esta pesquisa apresenta impressões, reflexões e considerações a respeito de uma experiência vivenciada no Ensino Médio, com estudantes de um Centro de Educação de Jovens e Adultos – CEJA, localizado em Manaus/Amazonas, em 2016. Nesta dissertação, buscou-se compreender em que aspectos um processo utilizando roteiros como estratégia de ensino e aprendizagem de química pode contribuir para a sistematização de estudo na Educação de Jovens e Adultos. A dissertação está organizada em quatro artigos que guardam conexões entre si e encontram-se sistematizados de acordo com os momentos vivenciados na pesquisa. A abordagem metodológica utilizada é de caráter qualitativa, utilizando-se como estratégia metodológica a pesquisa-ação centrada na utilização de três instrumentos de coleta de dados: 1) diários de campo como material de revisão, reflexão e reolhar das ações realizadas; 2) roteiros de aprendizagem, tanto como recurso para o processo educacional quanto instrumento avaliativo; e 3) questionários semiabertos, para a caracterização dos participantes e avaliação do processo. Para a interpretação dos dados obtidos, através dos diários e questionários, foi realizada uma análise empírico-interpretativa, procedendo-se ao estudo detalhado dos dados, tais como se mostram em seu conteúdo manifesto, procurando, na diversidade dos dados obtidos, significados a partir da percepção do próprio pesquisador e dos referenciais teóricos da pesquisa. Para a construção/análise dos roteiros utilizou-se como referencial teóricometodológico os fundamentos do Alinhamento Construtivo proposto por John Biggs. Os resultados foram analisados e organizados em três categorias: 1) Diagnóstico; 2) Ações desenvolvidas; e 3) Avaliação do processo. Foram analisados dez diários de campo, dois roteiros de aprendizagem referente ao conteúdo Linguagem Química e dois questionários semiabertos. Os dados da pesquisa evidenciaram que trabalhar com roteiros de aprendizagem possibilita a sistematização de estudo e melhorias no processo educacional no que tange à participação ativa dos estudantes na construção do conhecimento, além de promover um ambiente facilitador da aprendizagem para a EJA. / This research presents impressions, reflections and considerations about a lived experience in High School, with students of a Youth and Adult Education Center, located in Manaus / Amazonas, in 2016. In this dissertation, we sought to understand in which aspects a process using guides as a teaching and learning strategy of chemistry can contribute to the systematization of study in Young and Adults Education. A dissertation is organized into four articles that keep connections between them and are found in systems according to the moments experienced in the research. The methodological approach used is of a qualitative nature, using as a methodological strategy the action research centered on the use of three data collection instruments: 1) field journals as a material for review, reflection and review of the actions carried out; 2) learning guides, both as a resource for the educational process and as an evaluation tool; And 3) semi-open questionnaires, to characterize the participants and evaluate the process. For the interpretation of the data obtained through the journals and questionnaires, an empirical-interpretative analysis was carried out, with a detailed study of the data, as shown in its manifest content, seeking, in the diversity of the data obtained, meanings from the perception Of the researcher himself and of the theoretical references of the research For the construction / analysis of the guides the basis of the Constructive Alignment proposed by John Biggs was used as theoretical-methodological reference. The results were analyzed and organized into three categories: 1) Diagnosis; 2) Actions developed; and 3) Evaluation of the process. Ten field diaries were analyzed, two learning guides referring to the Chemistry’s Language content and two semi - open questionnaires. The research data showed that working with learning guides allows for the systematization of study and improvements in the educational process regarding the active participation of students in the construction of knowledge, as well as promoting an environment that facilitates learning for students of Young and Adults Education.
535

Saberes profissionais do guia de turismo: passeios turísticos em perspectiva etnográfica

Montes, Valéria Alves 13 December 2013 (has links)
Submitted by PPGE PPGE (pgedu@ufba.br) on 2014-07-11T16:22:48Z No. of bitstreams: 1 Tese_Final.pdf: 4034469 bytes, checksum: 008523e424528c6fe991ef1a8eed844e (MD5) / Approved for entry into archive by Maria Auxiliadora da Silva Lopes (silopes@ufba.br) on 2014-07-11T16:56:17Z (GMT) No. of bitstreams: 1 Tese_Final.pdf: 4034469 bytes, checksum: 008523e424528c6fe991ef1a8eed844e (MD5) / Made available in DSpace on 2014-07-11T16:56:18Z (GMT). No. of bitstreams: 1 Tese_Final.pdf: 4034469 bytes, checksum: 008523e424528c6fe991ef1a8eed844e (MD5) / A presente tese tem como objeto de estudo o processo de mobilização e recontextualização dos saberes profissionais do Guia de Turismo em situação de trabalho. Busca compreender como os guias de turismo mobilizam seus saberes e os recontextualizam na prática profissional e quais significados associam a tais conhecimentos. A pesquisa realiza-se mediante uma abordagem qualitativa utilizando o método etnográfico que possibilita a análise e a compreensão dos acontecimentos, das práticas, das situações de imprevistos em passeios turísticos e em traslados no aeroporto. Os sujeitos da pesquisa são guias de turismo com classificação em Guia de Turismo Regional que atuam no Estado de Alagoas, devidamente cadastrados pelo Instituto Brasileiro de Turismo – EMBRATUR, nos termos da Lei no. 8623, de 28 de janeiro de 1993. Para a realização da pesquisa são utilizados os dispositivos entrevista aberta e observação participante. Para o desenvolvimento deste estudo utilizam-se as categorias teóricas sobre recontextualização do conhecimento, reflexividade e saber profissional através de diversos olhares. Os resultados obtidos evidenciam que em contexto de trabalho os guias de turismo mobilizam e recontextualizam três saberes fundamentais: Saber turístico; Saber comunicacional; Saber vender e negociar (comercializar). / ABSTRACT The object of this thesis is the process of mobilization and recontextualization of professional knowledge of Tourist Guides at a work situation. It aims to understand how tour guides mobilize their knowledge and recontextualizeitin professional practice and also aimed to understand which meanings a re associated with such knowledge.The research was developed through a qualitative approach using the ethnographic method that enables the analysis and understanding of events, practices, unexpected situations during tours and transfers from the airport. T he subjects of this research were tour guides with Regional Tourist Guide Classification, operating in the State of Alagoas, Brazil, fully registered by the Brazilian Institute of Tourism - EMBRATUR, under the Law no. 8623, created on January 28, 1993.In o rder to have the research developed, some techniques, such as open interviews and participant observation were used. To produce the results, several techniques were used, such as the theoretical categories of recontextualization of knowledge, reflexivity a nd professional knowledge through various views.The results showed that in their workplace, tour guides mobilize and recontextualize three fundamental types of knowledge: Tourist knowledge; Communication knowledge; Sell and Trade know - how (marketing).
536

A educação de jovens e adultos por meio de roteiros de aprendizagem no ensino de química

Costa, Mauro Melo January 2017 (has links)
Esta pesquisa apresenta impressões, reflexões e considerações a respeito de uma experiência vivenciada no Ensino Médio, com estudantes de um Centro de Educação de Jovens e Adultos – CEJA, localizado em Manaus/Amazonas, em 2016. Nesta dissertação, buscou-se compreender em que aspectos um processo utilizando roteiros como estratégia de ensino e aprendizagem de química pode contribuir para a sistematização de estudo na Educação de Jovens e Adultos. A dissertação está organizada em quatro artigos que guardam conexões entre si e encontram-se sistematizados de acordo com os momentos vivenciados na pesquisa. A abordagem metodológica utilizada é de caráter qualitativa, utilizando-se como estratégia metodológica a pesquisa-ação centrada na utilização de três instrumentos de coleta de dados: 1) diários de campo como material de revisão, reflexão e reolhar das ações realizadas; 2) roteiros de aprendizagem, tanto como recurso para o processo educacional quanto instrumento avaliativo; e 3) questionários semiabertos, para a caracterização dos participantes e avaliação do processo. Para a interpretação dos dados obtidos, através dos diários e questionários, foi realizada uma análise empírico-interpretativa, procedendo-se ao estudo detalhado dos dados, tais como se mostram em seu conteúdo manifesto, procurando, na diversidade dos dados obtidos, significados a partir da percepção do próprio pesquisador e dos referenciais teóricos da pesquisa. Para a construção/análise dos roteiros utilizou-se como referencial teóricometodológico os fundamentos do Alinhamento Construtivo proposto por John Biggs. Os resultados foram analisados e organizados em três categorias: 1) Diagnóstico; 2) Ações desenvolvidas; e 3) Avaliação do processo. Foram analisados dez diários de campo, dois roteiros de aprendizagem referente ao conteúdo Linguagem Química e dois questionários semiabertos. Os dados da pesquisa evidenciaram que trabalhar com roteiros de aprendizagem possibilita a sistematização de estudo e melhorias no processo educacional no que tange à participação ativa dos estudantes na construção do conhecimento, além de promover um ambiente facilitador da aprendizagem para a EJA. / This research presents impressions, reflections and considerations about a lived experience in High School, with students of a Youth and Adult Education Center, located in Manaus / Amazonas, in 2016. In this dissertation, we sought to understand in which aspects a process using guides as a teaching and learning strategy of chemistry can contribute to the systematization of study in Young and Adults Education. A dissertation is organized into four articles that keep connections between them and are found in systems according to the moments experienced in the research. The methodological approach used is of a qualitative nature, using as a methodological strategy the action research centered on the use of three data collection instruments: 1) field journals as a material for review, reflection and review of the actions carried out; 2) learning guides, both as a resource for the educational process and as an evaluation tool; And 3) semi-open questionnaires, to characterize the participants and evaluate the process. For the interpretation of the data obtained through the journals and questionnaires, an empirical-interpretative analysis was carried out, with a detailed study of the data, as shown in its manifest content, seeking, in the diversity of the data obtained, meanings from the perception Of the researcher himself and of the theoretical references of the research For the construction / analysis of the guides the basis of the Constructive Alignment proposed by John Biggs was used as theoretical-methodological reference. The results were analyzed and organized into three categories: 1) Diagnosis; 2) Actions developed; and 3) Evaluation of the process. Ten field diaries were analyzed, two learning guides referring to the Chemistry’s Language content and two semi - open questionnaires. The research data showed that working with learning guides allows for the systematization of study and improvements in the educational process regarding the active participation of students in the construction of knowledge, as well as promoting an environment that facilitates learning for students of Young and Adults Education.
537

Estudo de guias periodicamente segmentados usando o método dos elementos finitos / Study of periodically segmented waveguides using the finite element method

Rubio Noriega, Ruth Esther, 1987- 21 August 2018 (has links)
Orientador: Hugo Enrique Hernandez Figueroa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T13:36:44Z (GMT). No. of bitstreams: 1 RubioNoriega_RuthEsther_M.pdf: 3183170 bytes, checksum: af9b79df81c18d5376bdcda8ca9f973a (MD5) Previous issue date: 2012 / Resumo: A principal contribuição deste trabalho _e a proposta da análise de estruturas periodicamente segmentadas na plataforma de silício sobre isolante (SoI), usando o método dos elementos finitos em um domínio computacional de duas dimensões...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The principal contribution of this work is to propose the analysis of grating periodic structures on the silicon-on-insulator platform through the finite element method in a two dimension computational domain...Note: The complete abstract is available with the full electronic document / Mestrado / Telecomunicações e Telemática / Mestra em Engenharia Elétrica
538

[en] ANALYSIS OF OPTICAL WAVEGUIDES CONTAINING ARBITRARILY NANLINEAR MATERIALS / [pt] ANÁLISE DE GUIAS DE ONDA ÓTICOS CONTENDO MATERIAIS ARBITRARIAMENTE NÃO LINEARES

ANA CECILIA PEIXOTO ZABEU 09 November 2006 (has links)
[pt] O objetivo deste trabalho é o estudo das características de propagação de ondas eletromagnéticas em guias de onda dielétricos contendo materiais arbitrariamente não lineares representados por uma distribuição de índice de refração que depende da intensidade local do sinal. Os guias de onda considerados neste trabalho podem ser analisados por meio de uma equação de onda unidimensional. Devido à presença de materiais não lineares, esta equação admite solução analítica apenas para certos tipos de não linearidade. De modo a permitir um estudo mais abrangente, uma solução numérica é desenvolvida para a equação de onda não linear. Esta solução numérica é então utilizada no estudo das características de propagação de guias de onda dielétricos em diversas configurações e diferentes tipos de onda dielétricos em diversas configurações e diferentes tipos de distribuição de índice de refração não linear, tanto em polarização TE como TM. O estudo mostra que estes guias de onda apresentam propriedades de propagação de potencial aplicação em dispositivos para um processador ótico de sinais ou para um computador ótico, como por exemplo histerese e bi-estabilidade óticas. É feito ainda um estudo da estabilidade das soluções da equação de onda não linear, sendo verificado que certas porções das soluções são instáveis, isto é, sofrem alteração à medida em que se deslocam ao longo do guia de onda. Além disso, foi observado a possibilidade de ocorrência, nas soluções instáveis, de rotas para o caos quando a potência do sinal é aumentada gradativamente. Em todos as etapas deste trabalho, os resultados foram comparados com outros métodos existentes na literatura. / [en] In this work, the propagation characteristics of electromagnetics waves in dieletric waveguides with arbitarily non-linear materiais, represented by a distribution of refractive index that depends on the local intensity of the signal, is presented. The waveguides here considered are analysed by means of an unidimensional equation. Due to the non- linearity of the materials this equation has analytical solution only for few types of non-linearities. To permit a more abrangent study, a numerical solution for the non- linear wave equation was developed. This solution is applied to the study of propagation characteristics of dielectric waveguides with different distributions of refractive index, either for TE and TM polarization. It is shown that these waveguides have propagation properties, like hysteresis and optical bi-stability, that fine applications in optical devices and optical computers. It´s also made a study of the stability of the solution of non-linear wave equation, showing that some portions of the solutions are usntable that is, they are a function of the observation point in the waveguide. The possibility of CAOS for unstable solutions, when the power is gradually increased, was also observed. At each step of this work, all results are compared with those of other methods of the literature.
539

Sound propagation modelling in urban areas : from the street scale to the neighbourhood scale / Modélisation de la propagation acoustique en milieu urbain : de la rue au quartier

Molerón Bermúdez, Miguel Ángel 30 November 2012 (has links)
Afin de réduire le bruit dans les villes, il est nécessaire d’avoir une bonne compréhension de la propagation acoustique en milieu urbain. Il existe aujourd’hui des logiciels commerciaux qui permettent de modéliser des champs acoustiques urbains à des coûts de calcul raisonnables. Toutefois, ces outils sont basés principalement sur des approches énergétiques qui ne contiennent pas d’informations sur la phase. Pour cette raison, elles ne permettent pas la prise en compte d’effets d’interférence (par exemple, des résonances), nous offrant ainsi une description physique limitée du champacoustique. Inversement, des méthodes ondulatoires classiques (FEM, BEM, FDTD) permettent de prendre en compte ces effets. Or, en raison de la discrétisation et de la grande extension du domaine de propagation, leur utilisation est généralement limitée aux très basses fréquences.L’objectif principal de cette thèse est de développer des méthodes ondulatoires performants, dans le domaine fréquentiel et temporel, nous permettant de modéliser la propagation acoustique dans des zones urbaines étendues. L’approche proposée est basée sur une formulation mixte modale–éléments finis. L’idée clé de cette méthode estde considérer la rue comme un guide d’ondes ouvert, dont la base modale est composée de modes de fuite (modes qui rayonnent une partie de leur énergie en se propageant). Cette approche combine une description multimodale du champ acoustique dans la direction longitudinale et un calcul par éléments finis des modes propres transverses.L’approche a été mise en oeuvre précédemment à l’échelle d’une seule rue. Dans cette thèse, nous nous intéressons à l’extension de la méthode à l’échelle du quartier, afin de modéliser la propagation dans des milieux contenant un grand nombre de rues interconnectées. Une version simplifiée dans le domaine temporel, contenant uniquement lemode de propagatif le moins fuyant, est également développée.En nous basant sur ces approches, nous étudions des phénomènes ondulatoires qui peuvent apparaître dans des configurations urbaines particulières. Plus précisément, nous nous intéressons à l’interaction des modes de la rue avec des résonances dans une cour intérieure adjacente, ainsi qu’à la formation de bandes de fréquences interditesdans des réseaux périodiques de rues interconnectées. Le résultat principal de cette étude est que, malgré la forte présence de pertes par radiation dans le milieu, des effets de résonance importants peuvent encore se produire. Les résultats présentés dans ce manuscrit mettent en évidence l’importance d’une approche ondulatoire pour décrirecorrectement des champs acoustiques aux basses fréquences, et ils suggèrent l’usage potentiel de ces phénomènes afin de contrôler la propagation acoustique dans le milieu.Enfin, nous présentons une étude sur l’utilisation de métasurfaces (surfaces contenant un réseau de résonateurs) pour améliorer la performance des murs antibruit. Nous démontrons que, grâce à l’excitation des résonances locales sur la métasurface, il est possible d’obtenir des propriétés non conventionnelles, comme par exemple des angles de réflexion négatifs ou de l’absorption acoustique aux basses fréquences. / The improvement of the urban sound environment requires a good understanding of the acoustic propagation in urban areas. Available commercial softwares give the possibility to simulate urban acoustic fields at relatively low computational costs. However, these tools are mainly based on energy methods that do not contain information on the phase. Therefore, these tools are unable to capture interference effects (e.g., resonances), providing a limited physical description of the acoustic field. Conversely, classical wave methods such as FEM, BEM or FDTD give the possibility to model interference effects, but their use is often restricted to very low frequencies due to discretisation and the huge extension of the propagation domain.The main goal of this thesis is to develop efficient wave methods for the acoustic propagation modelling in extended urban areas, both in the frequency and time domain. The proposed approach is based on a coupled modal–finite elements formulation. The key idea is to consider the urban canyon as an open waveguide with a modal basis composedof leaky modes, i.e., modes that radiate part of their energy into the atmosphere as they propagate. The approach combines a multimodal description of the acoustic field in the longitudinal direction and a finite elements computation of the transverseeigenmodes. This coupled approach, which has been successfully implemented at the scale of a single street, is extended in the present manuscript at a larger scale (the neighbourhood scale), in order to model problems arising in propagation domains containing many interconnected streets. A time domain version of the method, containing only the least damped mode, is also proposed.Using these methods, we investigate wave phenomena arising in specific urban configurations, as forbidden frequency bands in periodic networks of interconnected streets, and resonances in inner yards. It is found that, despite the presence of significant radiative losses in the propagation medium, strong interference effects are still observed. Not only this result highlights the relevance of a wave approach to describe accurately urban acoustic fields at low frequencies, but it suggest the potential use of these phenomena to control the acoustic propagation in urban environments.The last part of this dissertation presents a preliminary study on the use of metasurfaces (surfaces decorated with an array of resonators) to improve the performance of noise barriers. It is shown that, exciting resonances in these structures, it is possible to achieve some unconventional behaviours, including negative angles of reflection and low frequency sound absorption.
540

A descriptive study of the effectiveness of an independent living program

Asher, Sidney E. 01 January 1996 (has links)
The project is concerned with the effectiveness of the Independent Living Program (ILP) in assessing the effectiveness of preparing youth for emancipation from the foster care system. Specifically, the project focused on ILP participants' preparedness to live independently as determined by: education, housing, employment/career, and money management skills attained.

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