• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 14
  • 9
  • 7
  • 5
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 64
  • 20
  • 19
  • 14
  • 12
  • 10
  • 9
  • 8
  • 8
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 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.
41

Practical Digital Library Generation into DSpace with the 5S Framework

Gorton, Douglas Christopher 30 April 2007 (has links)
In today's ever-changing world of technology and information, a growing number of organizations and universities seek to store digital documents in an online, accessible manner. These digital library (DL) repositories are powerful systems that allow institutions to store their digital documents while permitting interaction and collaboration among users in their organizations. Despite the continual work on DL systems that can produce out-of-the-box online repositories, the installation, configuration, and customization processes of these systems are still far from straightforward Motivated by the arduous process of designing digital library instances; installing software packages like DSpace and Greenstone; and configuring, customizing, and populating such systems, we have developed an XML-based model for specifying the nature of DSpace digital libraries. The ability to map out a digital library to be created in a straightforward, XML-based way allows for the integration of such a specification with other DL tools. To make use of DL specifications for DSpace, we create a DL generator that uses these models of digital library systems to create, configure, customize, and populate DLs as specified. We draw heavily on previous work in understanding the nature of digital libraries from the 5S framework for digital libraries. This divides the concerns of digital libraries into a complex, formal representation of the elements that are basic to any minimal digital library system including Streams, Structures, Spaces, Scenarios, and Societies. We reflect on this previous work and provide a fresh application of the 5S framework to practical DL systems. Given our specification and generation process, we draw conclusions towards a more general model that would be suitable to characterize any DL platform with one specification. We present this DSpace DL specification language and generator as an aid to DL designers and others interested in easing the specification of DSpace digital libraries. We believe that our method will not only enable users to create DLs more easily, but also gain a greater understanding about their desired DL structure, software, and digital libraries in general. / Master of Science
42

Commande des systèmes à commutation : applications aux systèmes électriques / Control of switched systems : application to electrical systems

Amet, Leonardo 25 September 2014 (has links)
Dans ce travail de thèse, réalisé dans le cadre d'une bourse CIFRE entre le laboratoire ECS-Lab et l'entreprise GS Maintenance, nous nous sommes intéressés au contrôle et à l'observation des systèmes électriques, particulièrement les convertisseur multicellulaires séries et les moteurs à courant continu série.Dans la topologie des convertisseurs multicellulaires il est nécessaire d'équilibrer les tensions des condensateurs flottants à des valeurs spécifiques. Les techniques de commande par Modulation de Largeur d'Impulsions (MLI) permettent cet équilibrage, mais favorisent les dynamiques lentes. De plus, si le nombre de cellules est non premier, il existe des rapport cycliques qui déstabilisent le convertisseur. Afin de pallier à ces inconvénients, dans la première partie de la thèse des commandes directes basées sur les modes glissants sont proposées pour le convertisseur multicellulaire série à deux et trois cellules. Ces commandes sont simples et permettent une dynamique rapide, pouvant être étendues à des convertisseurs à nombre de cellules quelconque. Ces commandes sont testées en simulation et expérimentalement via un système temps réel dSpace sur un convertisseur multicellulaire à deux et trois cellules réalisé au cours de cette thèse au sein du laboratoire ECS-Lab. Il est important de souligner qu'une version industrielle du convertisseur a été réalisée au sein de l'entreprise GS Maintenance et vendue à l'Université du Qatar.Par ailleurs, dans le cadre de l'application du convertisseur multicellulaire une commande par modes glissants de type Zig-Zag est proposée pour pallier aux problèmes de quantification et saturation des actionneurs.La deuxième partie du travail a été consacrée à la synthèse d'un observateur/estimateur de type super-twisting pour estimer la vitesse d'un moteur à courant continu série sans capteur mécanique. La stratégie d'observation proposée est dédiée à une application industrielle qui concerne le forage pétrolier. Elle permet d'apporter une solution au problème d'observation généré par le fonctionnement à zéro ou faible courant. Cette stratégie a été testée sur un banc expérimental développé au cours de cette thèse au sein de l'entreprise GS Maintenance. / In this thesis , conducted in the context of a grant CIFRE between laboratory ECS-Lab and the company GS Maintenance, we focused on the control and observation of electrical systems, particularly multicellular converter series and the series DC motor.The floating voltages of the multicell topology need to be balanced to specific values. PWM control techniques provide such a balance but favor the slow dynamics. Moreover, if the numbers of cells is not prime, there exist duty-cycles which could destabilize the converter. To overcome these drawbacks, we propose direct control strategies based on sliding mode techniques for 2 and 3-cell converters. These are simple, allow fast dynamics, and can be easily extended to any number of cell with little overhead. They have been tested in simulation and experimentally via a real-time dSpace board on a 2 and 3-cell converter develloped during this thesis at ECS-Lab. It is important to emphasize that an industrial version of the converter has been manufactured at GS Maintenance and sold to Qatar University.Moreover, in the context of the appication of multicell converters, a Zig-Zag sliding mode control law has been proposed to overcome quantization and saturation problems found in real actuators.The second part of this work adresses the synthetization of an super-twistign observer/estimator scheme to estimate the speed of a sensorless DC series motor. The proposed observation strategy is dedicated to an industrial application in the context of oil drilling. It provides a solution to the problem of observation generated by operating at zero or low current. This strategy has been tested on an experimental bench developed in this thesis within GS Maintenance.
43

Gerenciamento de informações sobre o setor cultural : proposição de um repositório digital

Souza, Jordan Antonio de 21 May 2015 (has links)
Submitted by Jordan (jordanbiblio@gmail.com) on 2016-09-21T14:34:30Z No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2016-09-21T14:47:29Z (GMT) No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) / Made available in DSpace on 2016-09-21T14:47:29Z (GMT). No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) Previous issue date: 2015-05-21 / Nos últimos anos observa-se uma maior valorização do patrimônio cultural brasileiro, principalmente no que tange as ações voltadas para salvaguardar o patrimônio imaterial. O registro de práticas, saberes, festividades e outras manifestações culturais não são mais restritas às ações de reprodução de práticas culturais, mas também resulta na produção de diversos registros bibliográficos, fotográficos, fílmicos e outros documentos em diversos suportes que capturam, registram e possibilitam o conhecimento das informações presentes nestas atividades. O uso cada vez mais frequente das mídias tecnológicas, principalmente à internet, enquanto canal de comunicação e divulgação do patrimônio cultural, festividades, entre outros eventos, implica no surgimento de muitas imagens, vídeos e produções bibliográficas sobre determinadas manifestações culturais que podem ser encontradas na rede e estão disponíveis para acesso público, porém a recuperação deste material enquanto fonte de informação se dá de forma aleatória, pois não foram observados alguns requisitos necessários para a disponibilização destes no ciberespaço. Busca-se com o desenvolvimento desta pesquisa possibilitar maior visibilidade ao setor cultural Mato-Grossense, por meio de um repositório digital para armazenamento e divulgação de documentos, vídeos, sons e outras produções advindas de projetos voltados para a Economia Criativa e o Patrimônio Cultural Imaterial Mato-Grossense. Além de colaborar com a promoção e divulgação do patrimônio cultural imaterial, o Repositório Digital – Cultura do Mato, criado com o software DSpace, contribuirá com a preservação dos conhecimentos tradicionais ao mesmo tempo em que viabilizará o acesso a produção e consumo de informações sobre cultura no estado de Mato Grosso. No primeiro capítulo apresenta-se a introdução da pesquisa discorrendo sobre o porquê de seu desenvolvimento, os objetivos envolvidos e a metodologia aplicada. No segundo capítulo discorre-se sobre os conceitos e informações referentes ao Patrimônio Cultural, dando ênfase na Cultural Imaterial de Mato Grosso, pautando-se principalmente em documentos produzidos pelo IPHAN. O terceiro capítulo discorre sobre a o papel dos Repositórios na Gestão da Informação, focando a importância das Bibliotecas e Repositórios Digitais, bem como as contribuições oferecidas pelo uso do software DSpace no desenvolvimento destas Unidades de Informações Virtuais. O quarto capítulo compreende discussões a respeito do tratamento e representação de informações provenientes do Mapeamento da Cultura em Mato Grosso, o qual envolve projetos relacionados ao desenvolvimento da economia criativa mato-grossense, dos quais resultarão documentos digitais que deverão ser armazenados no repositório digital. O quinto capitulo apresenta a análise das funcionalidades do repositório, fornecendo informações sobre as questões que envolvem a instalação do software DSpace, o registro de comunidades, coleções e itens, e resultado dos testes com os recursos de busca do programa. O sexto capitulo é dedicado as considerações finais desta pesquisa. O desenvolvimento deste trabalho se pautará pelos princípios da pesquisa exploratória, funcionalista e qualitativa, pois suas técnicas permitem uma visão geral, a interpretação e a descrição dos objetos em análise. Por fim espera-se demonstrar os benefícios do emprego de tecnologias que envolvem a criação de um repositório digital, tanto no quesito armazenamento de informações existentes sobre a economia e o patrimônio cultural mato-grossense, quanto na recuperação, acesso e visibilidade destes recursos informacionais. / In the last years, we may observe a higher appreciation of the Brazilian cultural heritage, especially regarding the actions to safeguard intangible heritage. The registration of practice, knowledge, festivities and other cultural events is no longer restricted to breeding actions of cultural practices, but also results in the production of several bibliographic, photographic and filmic records and other documents in several media resources that capture, record and enable the knowledge of the information provided in these activities. The increasingly frequent use of technological media, especially the Internet, as a communication and promotion channel of cultural heritage, festivals and other events, results in the appearance of many images, videos and literature production about certain cultural events that can be found on the net and are available for public access, but recovery of this material as a source of information occurs randomly because some requirements for the provision of those materials in cyberspace were not observed. This research aims to bring to the spotlight the cultural sector of Mato Grosso, through a digital repository for storage and dissemination of documents, videos, sounds and other productions arising from projects focused on the Creative Economy and the Intangible Cultural Heritage of Mato Grosso. In addition to its collaboration with the promotion and dissemination of intangible cultural heritage, the Digital Repository - Mato's Culture, created with the software DSpace, will contribute to the preservation of traditional knowledge whereas will facilitate the access to production and consumption of culture information in Mato Grosso state. In the first chapter, the research introduction is shown discussing about the reason of its development, the involved objectives and the applied methodology. In the second chapter, we discuss about the concepts and information related to the Cultural Heritage, emphasizing the Intangible Culture of Mato Grosso, mainly based on documents produced by IPHAN. The third chapter discusses about the function of repositories in Information Management, focusing on the importance of Libraries and Digital Repositories,and the contributions offered by the use of DSpace software in developing these Virtual Information Units. The fourth chapter includes discussions about the processing andrepresentation of information from the Cultural Mapping in Mato Grosso, which involvesprojects related to the development of Mato Grosso's creative economy, from which digital documents will be resulted and must be stored in the digital repository. The fifth chapter presents the analysis of thefeatures of the repository, providing information on issues involving the installation ofDSpace software, the registration of communities, collections and items, and test results withsoftware search features. The sixth chapter is devoted to the final considerations of this research.The development of this paper will guide the principles of exploratory research, functionalist and qualitative because their techniques allow an overview, the interpretation and description of the objects in question. Finally expected to demonstrate the benefits of using technologiesinvolving the creation of a digital repositor both in the question storage existing informationon the economy and the Mato Grosso cultural patrimony, and the recovery, access andvisibility of these information resources.
44

Gerenciamento de informações sobre o setor cultural : proposição de um repositório digital

Souza, Jordan Antonio de 21 May 2015 (has links)
Submitted by Jordan (jordanbiblio@gmail.com) on 2016-09-21T14:34:30Z No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2016-09-21T14:47:29Z (GMT) No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) / Made available in DSpace on 2016-09-21T14:47:29Z (GMT). No. of bitstreams: 1 DISS_2015_Jordan Antonio de Souza.pdf: 3565067 bytes, checksum: a18e0b0860a9dcfbb559f94c2eddeeb6 (MD5) Previous issue date: 2015-05-21 / Nos últimos anos observa-se uma maior valorização do patrimônio cultural brasileiro, principalmente no que tange as ações voltadas para salvaguardar o patrimônio imaterial. O registro de práticas, saberes, festividades e outras manifestações culturais não são mais restritas às ações de reprodução de práticas culturais, mas também resulta na produção de diversos registros bibliográficos, fotográficos, fílmicos e outros documentos em diversos suportes que capturam, registram e possibilitam o conhecimento das informações presentes nestas atividades. O uso cada vez mais frequente das mídias tecnológicas, principalmente à internet, enquanto canal de comunicação e divulgação do patrimônio cultural, festividades, entre outros eventos, implica no surgimento de muitas imagens, vídeos e produções bibliográficas sobre determinadas manifestações culturais que podem ser encontradas na rede e estão disponíveis para acesso público, porém a recuperação deste material enquanto fonte de informação se dá de forma aleatória, pois não foram observados alguns requisitos necessários para a disponibilização destes no ciberespaço. Busca-se com o desenvolvimento desta pesquisa possibilitar maior visibilidade ao setor cultural Mato-Grossense, por meio de um repositório digital para armazenamento e divulgação de documentos, vídeos, sons e outras produções advindas de projetos voltados para a Economia Criativa e o Patrimônio Cultural Imaterial Mato-Grossense. Além de colaborar com a promoção e divulgação do patrimônio cultural imaterial, o Repositório Digital – Cultura do Mato, criado com o software DSpace, contribuirá com a preservação dos conhecimentos tradicionais ao mesmo tempo em que viabilizará o acesso a produção e consumo de informações sobre cultura no estado de Mato Grosso. No primeiro capítulo apresenta-se a introdução da pesquisa discorrendo sobre o porquê de seu desenvolvimento, os objetivos envolvidos e a metodologia aplicada. No segundo capítulo discorre-se sobre os conceitos e informações referentes ao Patrimônio Cultural, dando ênfase na Cultural Imaterial de Mato Grosso, pautando-se principalmente em documentos produzidos pelo IPHAN. O terceiro capítulo discorre sobre a o papel dos Repositórios na Gestão da Informação, focando a importância das Bibliotecas e Repositórios Digitais, bem como as contribuições oferecidas pelo uso do software DSpace no desenvolvimento destas Unidades de Informações Virtuais. O quarto capítulo compreende discussões a respeito do tratamento e representação de informações provenientes do Mapeamento da Cultura em Mato Grosso, o qual envolve projetos relacionados ao desenvolvimento da economia criativa mato-grossense, dos quais resultarão documentos digitais que deverão ser armazenados no repositório digital. O quinto capitulo apresenta a análise das funcionalidades do repositório, fornecendo informações sobre as questões que envolvem a instalação do software DSpace, o registro de comunidades, coleções e itens, e resultado dos testes com os recursos de busca do programa. O sexto capitulo é dedicado as considerações finais desta pesquisa. O desenvolvimento deste trabalho se pautará pelos princípios da pesquisa exploratória, funcionalista e qualitativa, pois suas técnicas permitem uma visão geral, a interpretação e a descrição dos objetos em análise. Por fim espera-se demonstrar os benefícios do emprego de tecnologias que envolvem a criação de um repositório digital, tanto no quesito armazenamento de informações existentes sobre a economia e o patrimônio cultural mato-grossense, quanto na recuperação, acesso e visibilidade destes recursos informacionais. / In the last years, we may observe a higher appreciation of the Brazilian cultural heritage, especially regarding the actions to safeguard intangible heritage. The registration of practice, knowledge, festivities and other cultural events is no longer restricted to breeding actions of cultural practices, but also results in the production of several bibliographic, photographic and filmic records and other documents in several media resources that capture, record and enable the knowledge of the information provided in these activities. The increasingly frequent use of technological media, especially the Internet, as a communication and promotion channel of cultural heritage, festivals and other events, results in the appearance of many images, videos and literature production about certain cultural events that can be found on the net and are available for public access, but recovery of this material as a source of information occurs randomly because some requirements for the provision of those materials in cyberspace were not observed. This research aims to bring to the spotlight the cultural sector of Mato Grosso, through a digital repository for storage and dissemination of documents, videos, sounds and other productions arising from projects focused on the Creative Economy and the Intangible Cultural Heritage of Mato Grosso. In addition to its collaboration with the promotion and dissemination of intangible cultural heritage, the Digital Repository - Mato's Culture, created with the software DSpace, will contribute to the preservation of traditional knowledge whereas will facilitate the access to production and consumption of culture information in Mato Grosso state. In the first chapter, the research introduction is shown discussing about the reason of its development, the involved objectives and the applied methodology. In the second chapter, we discuss about the concepts and information related to the Cultural Heritage, emphasizing the Intangible Culture of Mato Grosso, mainly based on documents produced by IPHAN. The third chapter discusses about the function of repositories in Information Management, focusing on the importance of Libraries and Digital Repositories,and the contributions offered by the use of DSpace software in developing these Virtual Information Units. The fourth chapter includes discussions about the processing andrepresentation of information from the Cultural Mapping in Mato Grosso, which involvesprojects related to the development of Mato Grosso's creative economy, from which digital documents will be resulted and must be stored in the digital repository. The fifth chapter presents the analysis of thefeatures of the repository, providing information on issues involving the installation ofDSpace software, the registration of communities, collections and items, and test results withsoftware search features. The sixth chapter is devoted to the final considerations of this research.The development of this paper will guide the principles of exploratory research, functionalist and qualitative because their techniques allow an overview, the interpretation and description of the objects in question. Finally expected to demonstrate the benefits of using technologiesinvolving the creation of a digital repositor both in the question storage existing informationon the economy and the Mato Grosso cultural patrimony, and the recovery, access andvisibility of these information resources.
45

PI-MQR adaptativo aplicado a um motor de indução trifásico utilizando a plataforma DSPACE1103 / PI-RLS Adaptive applied to an induction motor three-phase using DSPACE1103 platform

Silva, Paulo César da 10 July 2015 (has links)
Made available in DSpace on 2016-12-12T17:38:34Z (GMT). No. of bitstreams: 1 Paulo Cesar da Silva.pdf: 5331875 bytes, checksum: adf5bf8880e8e89421a2fd553c966530 (MD5) Previous issue date: 2015-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The electrical parameters of three-phase induction motors vary according to their operating point, with the temperature and also with the natural machine degradation. Since the design regulators are typically performed based on linear and simplified equations of the machine, the parametric variation can cause unwanted responses, since the motor behavior is non-linear and time variant. Thus, it is proposed in this work carry the identification of the electrical parameters of the induction motor using the estimator called Least Squares Recursive (RLS). Thus, with the parametric data updated every sampling period can be recalculated in real time the gains of the regulators are designed for controlling the induction machine and make minor mismatches. The experimental results were obtained with the processing performed by dSPACE hardware (DS1103), which has an interface with Matlab/Simulink, facilitating the use by the user and reducing the time taken for testing bench. The results of numerical and practical simulations show a comparison between the mesh proposal, the parametric identification and update of the gains of the controllers (adaptive control) and the mesh with controllers with fixed gains. / Os parâmetros elétricos do motor de indução trifásico variam conforme o seu ponto de operação, com a temperatura e também com a degradação natural da máquina. Visto que o projeto de reguladores são tipicamente realizados com base em equações lineares e simplicadas da máquina, a variação paramétrica pode causar respostas indesejadas, pois o comportamento do motor é não-linear e variante no tempo. Desta forma propõe-se neste trabalho realizar a identificação dos parâmetros elétricos do motor de indução, utilizando o estimador denominado de Mínimos Quadrados Recursivos (MQR). Assim, com os dados paramétricos atualizados a cada período de amostragem, pode-se recalcular em tempo real, os ganhos dos reguladores que são projetados para o controle da máquina de indução e tornar os descasamentos menores. Os resultados experimentais foram obtidos com o processamento realizado pelo hardware dSPACE (DS1103), que possui uma interface com o Matlab/Simulink, facilitando a utilização por parte do usuário e reduzindo o tempo dispendido para os testes em bancada. Os resultados de simulações numéricas e práticos apresentam uma comparação entre a malha proposta, com a identificação paramétrica e atualiza ção dos ganhos dos controladores (controle adaptativo) e a malha com controladores com ganhos fixos.
46

Structures et stratégies de commande des filtres actifs parallèle et hybride avec validations expérimentales / Structures and control strategies of parallel active and hybrid filters with experimental validations

Abdusalam, Mohamed Muftah 29 May 2008 (has links)
Ce manuscrit est consacré à la dépollution des réseaux électriques par les filtres actifs. Dans un premier temps, le filtre actif parallèle triphasé trois fils à structure tension y est étudié théoriquement, par simulation, puis expérimentalement. Une nouvelle stratégie de commande, basée sur la méthode des puissances instantanées et mettant en œuvre des « filtres multi-variables » est étudiée. Trois types de contrôleurs de courant sont envisagés : hystérésis classique, hystérésis modulée et MLI. L’hystérésis modulée est retenue car elle garantit simultanément la robustesse du système et une fréquence de commutation fixe. Un banc expérimental a permis de conforter les résultats obtenus par simulation. Ensuite, le filtre hybride parallèle (FHP) triphasé et l’optimisation de sa commande ont été examinés. L’objectif majeur est d’améliorer les performances de filtrage tout en s’attachant à minimiser la complexité de la commande. Le filtre hybride étudié est constitué d’un filtre actif triphasé à structure tension connecté en série avec un filtre triphasé passif de type LC, accordé sur l’harmonique 7. Nous avons proposé une première modification (commande dite « simplifiée ») de la commande classique dans le référentiel lié au synchronisme en introduisant des « filtres multi-variables » au lieu des filtres d’extraction classiques des deux boucles de contrôle, dites « feedback » et « feedforward ». Cette modification nous a permis de réduire considérablement la complexité de l’algorithme de commande (suppression de la PLL de la boucle « feedforward ») tout en améliorant les performances du filtrage. Ensuite, la PLL de la boucle « feedback » a également été supprimée. Ces optimisations ont conduit à des résultats de simulation très satisfaisants en terme de THD. Une nouvelle commande du filtre hybride à trois bras a également été proposée. La boucle feedforward est alors divisée en deux boucles. La première est destinée à supprimer l’harmonique 5 et l’autre l’harmonique 7 alors que le filtre passif est alors accordé sur l’harmonique 11. Les résultats de simulation obtenus sont très satisfaisants. Pour conclure cette étude théorique, nous avons étudié une nouvelle topologie de filtre hybride basée sur un onduleur triphasé à deux bras avec un condensateur à point milieu. Un flot de conception et d’implantation sur cible FPGA de commandes numériques de systèmes de puissance a été appliqué au cas de la commande dite « simplifiée » du FHP. Chaque étape a été détaillée et validée soit par simulation en mode continu ou en mode discret, soit expérimentalement lors de la programmation finale d’un composant FPGA de type Stratix II de la famille Altera, intégrant l’ensemble de la commande numérique du FHP. / In this thesis, and with the aim to improve the power quality, we have theoretically and experimentally studied two types of filtering, the shunt active power filter and hybrid, passive and active power filter. The modelling and simulation of a parallel active filter with three types of current controllers (MLI, classical hysteresis and modulated hysteresis) are first studied. The behavior of the active filter under transient conditions is also presented. Then, we have experimentally validated the simulation results obtained for the modulated hysteresis. The test bench consists of a parallel active filter, a non-linear load, a digital control system DSPACE (DS1104) and an analog card. Next, we studied by modelling and simulation the hybrid filter. For both cases, the use of multi-variable filter improves the filtering performances. An experimental prototype called "FPGA in the Loop" has been implemented to validate digital control of hybrid filter. In addition, a comparison between the two filters has been realised in order to find the best way to reduce network harmonic currents.
47

Encontrabilidade da informação em repositórios digitais: um estudo de eye-tracking nos repositórios institucionais da USP, UNESP e UNICAMP / Findability of information in digital repositories: an eye-tracking study in the institutional repositories of USP, UNESP and UNICAMP

Sanchez, Fernanda Alves [UNESP] 25 May 2018 (has links)
Submitted by Fernanda Alves Sanchez (feersanchez@gmail.com) on 2018-06-25T16:29:13Z No. of bitstreams: 1 Dissertação_Fernanda_ENTREGA NA PÓS.pdf: 5693756 bytes, checksum: ed059e76f765a4c0a0f0bada25f88c18 (MD5) / Rejected by Satie Tagara (satie@marilia.unesp.br), reason: Falta a ficha catalográfica: - é elemento obrigatório em trabalhos acadêmicos, e deve ser elaborada por um bibliotecário; - para obter a ficha catalográfica de seu trabalho, você pode enviar um e-mail para bibl-aquisicao@marilia.unesp.br com os seguintes dados do seu trabalho: folha de rosto, resumo com palavras-chave, número da última folha do trabalho, número inicial e final da seção de referências. Após recebê-la, é só inseri-la na sequência da página de rosto (na versão impressa é no verso). on 2018-06-25T18:05:28Z (GMT) / Submitted by Fernanda Alves Sanchez (feersanchez@gmail.com) on 2018-06-25T18:24:22Z No. of bitstreams: 1 Dissertação_Fernanda_ENTREGA NA PÓS.pdf: 5721319 bytes, checksum: cc182af24a14e2950a2a14c6b0b8516e (MD5) / Approved for entry into archive by Satie Tagara (satie@marilia.unesp.br) on 2018-06-25T19:11:55Z (GMT) No. of bitstreams: 1 sanchez_fa_me_mar.pdf: 5721319 bytes, checksum: cc182af24a14e2950a2a14c6b0b8516e (MD5) / Made available in DSpace on 2018-06-25T19:11:55Z (GMT). No. of bitstreams: 1 sanchez_fa_me_mar.pdf: 5721319 bytes, checksum: cc182af24a14e2950a2a14c6b0b8516e (MD5) Previous issue date: 2018-05-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O aumento exponencial da produção de dados e informações científicas está diretamente associado à evolução das tecnologias digitais de informação e comunicação e, diante desse cenário, percebe-se a necessidade de implementação pelas instituições de ambientes informacionais digitais que possam reuni-los, organizá-los, disseminá-los e preservá-los. Os repositórios institucionais, objetos de estudo dessa pesquisa, são ambientes potenciais para tais ações; sua implementação, entretanto, deve atender as necessidades informacionais de seu público-alvo, tornando-se necessária a aplicação de métodos, técnicas e atributos que promovam a encontrabilidade da informação científica. Com o objetivo de verificar se os repositórios institucionais têm sido implementados a partir de atributos que viabilizem a encontrabilidade da informação pelos sujeitos informacionais, este estudo utiliza como referência os repositórios institucionais das três universidades estaduais do estado de São Paulo – USP, UNESP e UNICAMP. Para viabilizar o cumprimento dos objetivos da pesquisa, é utilizado o método quadripolar que permite dinamicidade e flexibilidade para o desenvolvimento do estudo por meio de seus quatro polos: epistemológico, teórico, técnico e morfológico. O polo epistemológico abordou o paradigma pós-custodial da Ciência da Informação e a Pós-Fenomenologia para fundamentar o estudo, epistemologicamente. O polo teórico permitiu buscar aportes relacionados às temáticas que permeiam o objeto de pesquisa, quais sejam: Repositórios Digitais, com ênfase nos Repositórios Institucionais, o DSpace como tecnologia para implementação, e a Encontrabilidade da Informação. O polo técnico evidencia os procedimentos metodológicos para a realização do estudo: pesquisa bibliográfica e revisão de literatura para abordar os fundamentos epistemológicos e teóricos mencionados, além de pesquisa aplicada, que ocorreu em duas fases, sendo a primeira a aplicação do “Checklist para avaliação da Encontrabilidade da Informação em Repositórios Institucionais” nos repositórios institucionais da USP, UNESP e UNICAMP, por meio da técnica de observação, e a segunda se refere à aplicação de tarefas junto aos mestrados dos Programas de Pós-Graduação em Educação e Fonoaudiologia da UNESP de Marília, a partir da tecnologia de eye-tracking (rastreamento ocular), nos três repositórios, sendo executada, juntamente com a técnica de protocolo verbal e, posteriormente, entrevistas. O polo morfológico se destina à apresentação dos resultados da pesquisa, bem como à proposta de recomendações para os repositórios institucionais analisados. A partir da avaliação com o checklist, os resultados revelaram problemáticas referentes aos atributos Folksonomia, Descoberta de Informação e Acessibilidade e Usabilidade, nos três repositórios. Em ao menos um deles, foram observadas problemáticas com os atributos Taxonomias navegacionais, Mediação dos Profissionais da Informação e Mobilidade, Convergência e Ubiquidade. Considerando as limitações desta técnica de coleta de dados, não foi possível avaliar os atributos Instrumentos de controle terminológico, Intencionalidade e Mediação dos informáticos. Em um segundo momento, foi possível avaliar o atributo de Descoberta de Informação com a tecnologia de eye-tracking. Após as avaliações realizadas, foram geradas dez recomendações de encontrabilidade da informação para repositórios institucionais. / The exponential increase in the production of scientific data and information is directly associated with the evolution of digital information and communication technologies and, in view of this scenario, it is noticed the need for institutions to implement digital information environments that can bring them together, organize them, disseminate and preserve them. Institutional repositories, objects of study of this research, are potential environments for such actions; its implementation, however, must meet the information needs of its target audience, making it necessary to apply methods, techniques and attributes that promote the finding of scientific information. With the objective of verifying that institutional repositories have been implemented based on attributes that enable information to be found by information subjects, this study uses as reference the institutional repositories of the three state universities of the state of São Paulo - USP, UNESP and UNICAMP. In order to achieve the objectives of the research, the four-pole method is used, which allows dynamicity and flexibility for the development of the study through its four poles: epistemological, theoretical, technical and morphological. The epistemological pole addressed the post-custodial paradigm of Information Science and Post-Phenomenology to support the study, epistemologically. The theoretical pole allowed the search for contributions related to the themes that permeate the research object, namely: Digital Repositories, with emphasis on Institutional Repositories, DSpace as technology for implementation, and Information Findability. The technical pole evidences the methodological procedures for carrying out the study: bibliographical research and literature review to address the epistemological and theoretical foundations mentioned, as well as applied research, which occurred in two phases, the first being the application of the "Checklist for evaluation of Information Finding in Institutional Repositories "in the institutional repositories of USP, UNESP and UNICAMP, through the observation technique, and the second refers to the application of tasks to the masters of the Graduate Programs in Education and Speech-Language Pathology of UNESP of Marília, from the eye-tracking technology, in the three repositories, being executed, along with the technique of verbal protocol and, later, interviews. The morphological pole is intended to present the results of the research, as well as to the proposed recommendations for the institutional repositories analyzed. From the evaluation with the checklist, the results revealed problems related to the attributes Folksonomy, Information Discovery and Accessibility and Usability, in the three repositories. In at least one of them, problems were observed with the attributes: Navigational Taxonomies, Mediation of Information Professionals and Mobility, Convergence and Ubiquity. Considering the limitations of this technique of data collection, it was not possible to evaluate the attributes of terminological control instruments, intentionality and mediation of computer scientists. In a second moment, it was possible to evaluate the attribute of Information Discovery with eye-tracking technology. After the evaluations, ten information retrieval recommendations were generated for institutional repositories. / CAPES: 1660180
48

Bezsensorové polohové řízení solenoidu / Sensorless position control of solenoid valve

Keprt, Jaroslav January 2016 (has links)
This thesis deals with the determination of the position of the solenoid core in real time based on the measured current. The reference position of the current is used for feedback control of the solenoid. For this issue, software tool Matlab/Simulink was used. For current and temperature measurements, PCB circuits were created. The whole project was carried out on the dSPACE platform.
49

Implementation of an Actuator Placement, Switching Algorithm for Active Vibration Control in Flexible Structures

Swathanthira Kumar, Murali Murugavel Manjakkattuvalasu 20 November 2002 (has links)
"The recent years have seen the innovative system integration of a great many actuator technologies, such as point force actuators for space vehicle applications and the use of single fire actuators; such as pyrocharges to guide a free falling bomb to it’s target. The inherent limitations of these developments, such as nonlinear behavior under extreme environments and/or prolonged/repeated usage leading to a relaxation time component between firing of actuators and inherent system power limitations, have resulted in greater need for sophisticated control algorithms that allow for optimal switching between various actuators in any given embedded configuration so as to achieve the best possible performance of the system. The objective of this investigation is to offer a proof of concept experimental verification of a real time control algorithm, which switches between online piezoelectric actuators, employed for vibration control in an aluminum beam with fixed boundary conditions. In this investigation at a given interval of time, only one actuator is activated and the rest are kept dormant. The reason is to demonstrate the better vibration alleviation characteristics realized in switching between actuators depending on the state of the system, over the use of a single actuator that is always in fire mode. This effect is particularly pronounced in controlling systems affected by spatiotemporal disturbances. The algorithm can be easily adapted for various design configurations or system requirements. The optimality of switching is with respect to the minimal cost of an LQR performance index that corresponds to each actuator. Computer simulations with repeatable disturbance profiles, revealed that this algorithm offered better performance over the non-switched case. Performance measures employed were the time varying total energy norm of the dynamic system and position traces at any particular location on the beam. This algorithm was incorporated on a dSPACE rapid prototyping platform along with suitable hardware. Experimental and simulation results are discussed. "
50

Implementa??o de um buscador em reposit?rios institucionais abertos de pa?ses do Mercosul - recupera??o de metainforma??es

Melo, Matheus Le?o de 04 February 2016 (has links)
Submitted by Raniere Barreto (raniere.barros@ufvjm.edu.br) on 2018-10-26T18:24:24Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) matheus_leao_melo.pdf: 2496459 bytes, checksum: d05e0424e48fc7c4bfc6ec5b57683faa (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-11-10T10:37:32Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) matheus_leao_melo.pdf: 2496459 bytes, checksum: d05e0424e48fc7c4bfc6ec5b57683faa (MD5) / Made available in DSpace on 2018-11-10T10:37:32Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) matheus_leao_melo.pdf: 2496459 bytes, checksum: d05e0424e48fc7c4bfc6ec5b57683faa (MD5) Previous issue date: 2016 / A presente disserta??o debate a import?ncia da comunica??o cient?fica, as tecnologias e softwares utilizados como forma de dissemina??o do conhecimento cient?fico-acad?mico. Neste universo surge a necessidade cria??o de um buscador de metadados de portais de peri?dicos cient?ficos eletr?nicos e reposit?rios institucionais de Acesso Aberto de pa?ses membros do MERCOSUL, promovendo uma inova??o e integra??o da Comunica??o Cient?fica dos pa?ses do bloco. H? mais de tr?s s?culos os pesquisadores utilizam as revistas cient?ficas e as bibliotecas universit?rias para resguardar, divulgar, disseminar, validar, promover e repercutir os seus estudos e pesquisas, mas tamb?m como um banco de dados e propaga??o cient?fica para a cria??o de novos estudos a partir dessas difus?es cient?ficas. Com o exponencial crescimento da produ??o cient?fica e a sua propaga??o na internet, na virada do s?culo, como ferramenta de dissemina??o da produ??o cient?fica, surge o desafio da cria??o de um instrumento pragm?tico de organiza??o e busca de pesquisas cient?ficas dos pa?ses membros do MERCOSUL: O Buscador B?ho. / Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Tecnologia, Sa?de e Sociedade, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / ABSTRACT This dissertation discusses the importance of scientific communication, technologies and software used as a means of dissemination of scientific and academic knowledge. In this universe there is a need create a search engine for electronic journals portals metadata and institutional repositories Open Access MERCOSUR member countries, promoting innovation and integration of Scientific Communication of the bloc's countries. For more than three centuries researchers use scientific journals and university libraries to protect, disclose, disseminate, validate, promote and pass on his studies and research, but also as a database and scientific spreading to the creation of new studies from these scientific broadcasts. With the exponential growth of scientific production and its spread on the Internet at the turn of the century, as dissemination tool of scientific production, the challenge of creating a pragmatic instrument of organization and search of scientific research of the MERCOSUR member countries arises: The B?ho Searcher.

Page generated in 0.0531 seconds