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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.
121

Borboletas no semi?rido: sazonalidade e padr?es de diversidade de borboletas frug?voras em um ambiente extremo

Santos, Larissa Nascimento dos 19 June 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-06T21:17:19Z No. of bitstreams: 1 LarissaNascimentoDosSantos_DISSERT.pdf: 2260102 bytes, checksum: ca6ecb3068e94519806f21f62cc4d858 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-08T21:45:50Z (GMT) No. of bitstreams: 1 LarissaNascimentoDosSantos_DISSERT.pdf: 2260102 bytes, checksum: ca6ecb3068e94519806f21f62cc4d858 (MD5) / Made available in DSpace on 2016-06-08T21:45:50Z (GMT). No. of bitstreams: 1 LarissaNascimentoDosSantos_DISSERT.pdf: 2260102 bytes, checksum: ca6ecb3068e94519806f21f62cc4d858 (MD5) Previous issue date: 2015-06-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / A distribui??o espa?o-temporal das popula??es reflete o ajuste de suas caracter?sticas biol?gicas ?s condi??es ambientais e intera??es bi?ticas, conforme elementos precursores adaptativos e filogen?ticos. A heterogeneidade de habitat e o clima estacional tendem a causar padr?es de atividade dos organismos e de diversidade de esp?cies. Por?m, esses padr?es sazonais e espaciais em comunidades de borboletas em ambientes secos ainda n?o s?o claros. Estudamos uma comunidade de borboletas frug?voras na ESEC Serid?, no nordeste do Brasil, com o intuito de caracterizar a guilda no semi?rido e verificar a contribui??o relativa de vari?veis clim?ticas e vegetacionais sobre a sua composi??o, diversidade e fenofaun?stica. As borboletas foram amostradas mensalmente, durante um ano, e a distribui??o das esp?cies foi associada ?s caracter?sticas estruturais de tr?s fitofisionomias (ex. riqueza e abund?ncia de esp?cies arb?reo-arbustivas, cobertura de dossel, cobertura de herb?ceas, serapilheira) e a dados climatol?gicos (temperatura, pluviosidade e umidade). Foram capturados 9580 indiv?duos de 16 esp?cies de borboletas, pertencentes a quatro subfam?lias (Biblidinae, Charaxinae, Nymphalinae e Satyrinae). A riqueza, abund?ncia e diversidade variaram em diferentes escalas, principalmente no tempo, sendo maiores na esta??o chuvosa, enquanto a ?-diversidade e turnover foram maiores na seca. A distribui??o das esp?cies seguiu principalmente as mudan?as de umidade, pluviosidade e fenologia vegetacional, n?o havendo limites definidos entre habitats. O per?odo de voo foi compartilhado dentro das subfam?lias, as quais devem ter resposta distinta aos est?mulos ambientais, como tamb?m responder ? fenologia de plantas hospedeiras e ter estrat?gias de reprodu??o distintas. Havendo inclusive, ind?cios de adapta??es fisiol?gicas e comportamentais como reprodu??o sazonal e estiva??o. Portanto, houve controle ambiental sobre a distribui??o e diversidade de esp?cies, com o papel chave da associa??o do clima e estrutura da vegeta??o na diferencia??o da comunidade em esta??es do ano, e da disponibilidade e qualidade de recursos sobre a varia??o de abund?ncia das esp?cies, em pequenas escalas. Tais resultados podem dar suporte ao biomonitoramento e conserva??o de ?reas preservadas, sobretudo em ambientes sob press?o antr?pica e de condi??es ambientais extremas como o semi?rido. / The spatial and temporal distribution of the population reflects the adjustment of their biological characteristics to environmental conditions and biotic interactions as adaptive and phylogenetic precursors elements. The habitat?s heterogeneity and alternating seasons tend to cause patterns of activity of organisms and species diversity. However, these seasonal and spatial patterns in butterfly communities in dry environments are not yet clear. We studied a community of frugivorous butterflies in ESEC Serid?, in northeastern Brazil, aiming to characterize the guild in semiarid and check the relative contribution of climate and vegetation variables on its composition, diversity and phenofaunistic. The butterflies were sampled monthly during one year, and the distribution of species was associated with structural characteristics of three vegetation types (eg. richness and abundance of tree and shrub species, canopy cover, herbaceous cover, litter) and climatological data (temperature, rainfall and humidity). We captured 9580 individuals of 16 species of butterflies belonging to four subfamilies (Biblidinae, Charaxinae, Nymphalinae and Satyrinae). The richness, abundance and diversity varied in different scales, especially in time, being higher in the rainy season, while the ?-diversity and turnover was higher in the dry. The distribution of species mainly followed the changes in humidity, rainfall and vegetation phenology, with no defined boundaries between habitats. The flight period was shared within subfamilies, which should have distinct response to environmental stimuli, as well as respond to the phenology of host plants and have different reproductive strategies. There is even evidence of physiological and behavioral adaptations as seasonal reproduction and aestivation. So there was environmental control over the distribution and diversity of species, with the key role climate Association and vegetation structure in the community of differentiation in the seasons, and the availability and quality of resources on the variation of species abundance in small scales. These results may support the biomonitoring and conservation preserved areas, particularly in environments under human pressure and extreme environmental conditions such as semi-arid.
122

Contribui??es para estrat?gia de controle aplicada ? gera??o fotovoltaica interconectada ? rede el?trica

Rocha, Thiago de Oliveira Alves 09 December 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-10T00:04:44Z No. of bitstreams: 1 ThiagoDeOliveiraAlvesRocha_TESE.pdf: 3728978 bytes, checksum: e47856c08795ec056c30763c0e338dad (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-10T23:32:23Z (GMT) No. of bitstreams: 1 ThiagoDeOliveiraAlvesRocha_TESE.pdf: 3728978 bytes, checksum: e47856c08795ec056c30763c0e338dad (MD5) / Made available in DSpace on 2016-06-10T23:32:23Z (GMT). No. of bitstreams: 1 ThiagoDeOliveiraAlvesRocha_TESE.pdf: 3728978 bytes, checksum: e47856c08795ec056c30763c0e338dad (MD5) Previous issue date: 2015-12-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Os sistemas de gera??o, que utilizam fontes renov?veis, est?o se tornando cada vez mais populares devido ? necessidade do incremento do uso da energia el?trica. Atualmente, as fontes renov?veis cooperam com a gera??o convencional, em decorr?ncia da limita??o do sistema na entrega da pot?ncia requerida, da necessidade da redu??o dos efeitos indesejados das fontes que utilizam combust?veis fosseis (polui??o) e a dificuldade de constru??o de novas linhas de transmiss?o e/ou distribui??o. Esta coopera??o se d? por meio da gera??o distribu?da. Desta forma, neste trabalho s?o propostas contribui??es para o sistema de controle utilizado para a interconex?o de sistemas PV (do ingl?s, Photovoltaic) de gera??o distribu?da com a rede el?trica trif?sica, por meio de filtros de conex?o do tipo LCL. A compensa??o da qualidade de energia no ponto de acoplamento comum (PAC) ? realizada garantindo-se que a rede el?trica forne?a, ou consuma apenas pot?ncia ativa e que suas correntes possuam baixo teor harm?nico. Diferentemente das t?cnicas tradicionais, que necessitam de esquemas para a detec??o harm?nica, a t?cnica utilizada realiza a compensa??o harm?nica sem a utiliza??o desses esquemas, controlando as correntes de sa?da do sistema de uma forma indireta. Para que haja um efetivo controle da tens?o do barramento CC (Corrente Cont?nua) ? utilizado o controlador robusto em modo dual DSM-PI (Proporcional Integral Dual em Modo Deslizante), que durante o transit?rio se comporta como um controlador em modo deslizante SM-PI (Proporcional Integral em Modo Deslizante), e em regime permanente se comporta como um PI (Proporcional Integral) convencional. Para o controle das correntes ? utilizado a estrat?gia de controle repetitivo, onde s?o utilizados controladores de dupla sequ?ncia (DSC) sintonizados na componente fundamental, no quinto e no s?timo harm?nico. As correntes de refer?ncia s?o alinhadas ao ?ngulo de fase do vetor tens?o da rede el?trica, obtido a partir do uso de um SRF-PLL (do ingl?s, Synchronous Reference Frame Phase-Locked-Loop). Com o intuito de obter a m?xima pot?ncia do array fotovoltaico ? utilizado um algoritmo de MPPT (do ingl?s, Maximum Power Point Tracking) sem a necessidade de adi??o de sensores. Resultados experimentais s?o apresentados para demonstrar a efic?cia do sistema de controle proposto. / Generation systems, using renewable sources, are becoming increasingly popular due to the need for increased use of electricity. Currently, renewables sources have a role to cooperate with conventional generation, due to the system limitation in delivering the required power, the need for reduction of unwanted effects from sources that use fossil fuels (pollution) and the difficulty of building new transmission and/or distribution lines. This cooperation takes place through distributed generation. Therefore, this work proposes a control strategy for the interconnection of a PV (Photovoltaic) system generation distributed with a three-phase power grid through a connection filter the type LCL. The compensation of power quality at point of common coupling (PCC) is performed ensuring that the mains supply or consume only active power and that his currents have low distorcion. Unlike traditional techniques which require schemes for harmonic detection, the technique performs the harmonic compensation without the use of this schemes, controlling the output currents of the system in an indirect way. So that there is effective control of the DC (Direct Current) bus voltage is used the robust controller mode dual DSMPI (Dual-Sliding Mode-Proportional Integral), that behaves as a sliding mode controller SM-PI (Sliding Mode-Proportional Integral) during the transition and like a conventional PI (Proportional Integral) in the steady-state. For control of current is used to repetitive control strategy, which are used double sequence controllers (DSC) tuned to the fundamental component, the fifth and seventh harmonic. The output phase current are aligned with the phase angle of the utility voltage vector obtained from the use of a SRF-PLL (Synchronous Reference Frame Phase-Locked-Loop). In order to obtain the maximum power from the PV array is used a MPPT (Maximum Power Point Tracking) algorithm without the need for adding sensors. Experimental results are presented to demonstrate the effectiveness of the proposed control system.
123

O olhar das institui??es de previd?ncia sobre a casa e a cidade: promo??o, financiamento e avalia??o de im?veis / The pension institutions view about the house and the city: promotion, financing and property evaluation

Lima, Luiza Maria Medeiros de 16 October 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-08T20:58:16Z No. of bitstreams: 1 LuizaMariaMedeirosDeLima_DISSERT.pdf: 13938873 bytes, checksum: ca97c9833171e42906b52ea8b220d81d (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-11T22:00:39Z (GMT) No. of bitstreams: 1 LuizaMariaMedeirosDeLima_DISSERT.pdf: 13938873 bytes, checksum: ca97c9833171e42906b52ea8b220d81d (MD5) / Made available in DSpace on 2016-07-11T22:00:39Z (GMT). No. of bitstreams: 1 LuizaMariaMedeirosDeLima_DISSERT.pdf: 13938873 bytes, checksum: ca97c9833171e42906b52ea8b220d81d (MD5) Previous issue date: 2015-10-16 / Os investimentos em moradia realizados pelas Caixas e Institutos de Aposentadoria e Pens?es em Natal, entre as d?cadas de 1930 e 1960, viabilizou a libera??o de cr?dito para constru??o e compra de casas, que contribu?ram para dinamizar o mercado imobili?rio natalense, em processo de consolida??o ? ?poca. Inseridas numa primeira proposta de pol?tica p?blica com abrang?ncia nacional delineada para habita??o social no pa?s, essas a??es demandaram a cria??o de uma s?rie de estruturas descentralizadas, sobretudo nas capitais, vinculadas aos Escrit?rios Centrais no Rio de Janeiro. Nas ag?ncias locais, uma rede de profissionais desenvolviam atividades variadas, que iam desde a concep??o e constru??o de empreendimentos at? o estudo rotineiro de propostas de financiamento de unidades isoladas. Esse contexto traz ? lume a avalia??o de im?veis, operada na escala local, como elemento essencial ? efetiva??o da pol?tica, permitindo a produ??o e a troca de dados sobre o valor de mercado das propriedades, fundada sobre a observa??o e interpreta??o dos espa?os de resid?ncia de diferentes grupos sociais, da cidade e de seus bairros. Dessa forma, objetiva-se contribuir para o entendimento da operacionaliza??o dessas a??es imobili?rias na legitima??o de pondera??es sobre o espa?o urbano e as resid?ncias disponibilizadas aos trabalhadores na capital potiguar. As fontes prim?rias principais foram as fichas de avalia??o imobili?rias dos processos prediais das CAP/IAP, arquivados no INSS-RN e sistematizados em parte no Banco de Dados Empreendimentos do HCURB. Tendo como fontes auxiliares jornais da ?poca, entrevistas e registro fotogr?fico in loco, foi poss?vel refletir sobre a constru??o de imagens fragmentadas da cidade, em fun??o dos interesses de investimentos particulares, dos associados, e com a produ??o direta das institui??es - enquanto autarquias corporativas de seguro social. Isso converge para um entendimento do papel dos engenheiros avaliadores no ?mbito dessas institui??es. As t?cnicas e os profissionais de avalia??o vinculados a ela podem ser vistos, nesse sentido, como parte de um sistema t?cnico-operacional que se estrutura sobre uma matriz de valores preconcebidos acerca dos significados da ?casa?. A busca por essa ?ess?ncia cient?fica? da avalia??o, mais a efici?ncia para a manipula??o de sistemas de cr?dito e investimento, mostram como estes ?rg?os, tanto marcam como representam, at? certo ponto, as faces contradit?rias de um grande esfor?o coletivo de constru??o de um ?Brasil moderno-industrial? e do ?novo homem trabalhador brasileiro?. / The investments of Caixas and Institutos de Aposentadoria e Pens?es (CAP and IAP) in homes of Natal, between the decades of 1930-60, helped to boost up the local real estate market in consolidation at the time. Inserted in the first national policy on social housing in the country, these operations have demanded the creation of a wide qualified organizational structure, which would be from the "Central Offices" of Rio de Janeiro to the decentralized units of the federal states. The professionals linked to the Local Agencies have developed, on this matter, from activities related to the design and construction of residential complexes, to the daily study of financing proposals in isolated units. As from these studies, the evaluation of shelters was essential to the effectiveness of the policy, resulting in the production of data on the market value of the properties by observing and issuing judgments upon the living quarters of different social groups. Given these considerations, the aim here is to contribute to the understanding on how to operate these real estate actions in the legitimization of boundaries about the urban space and dwellings available to workers in Natal. Therefore, the views of the city and constructions expressed by the evaluating engineers in their technical reports have been taken as the focus. Being the main primary sources of work, these reports are part of the edifices process of CAP/IAP regarding Natal, whose content is systematized in the database "Enterprises", the HCUrb Research Group. In addition, there were used local newspapers at the time and interviews with professionals as complementary sources. It was found that, in general, the evaluations have configured ? in a more everyday dimension of bureaucratic routines - a vehicle, among others, circulating ideas about "home" within the social security institutions, being imbued with assumptions historically constructed about the "modern habitat". Filled in loco, the reports expose the clash between modernizing ideals in vogue and clear limitations in the city scenario at the time. Fragmented images of the town are given to read through the labels assigned to the evaluated sites ? these being coated of certain "scientific" character - which both legitimated and contributed to the dynamics of appreciation/depreciation of the soil and to the socio-spatial differentiation. Contradictions were evident in the endorsement given by the technicians when financing of admittedly precarious homes for insured disadvantaged categories at the local level - such as industrial workers - while strict regulations were imposed to new construction, designed, above all, to better paid categories. By identifying raters engineers as urban agents, members of a technical-focused operating system for safety and efficiency in the real estate investments of those authorities corporatist, it is desired the usefulness of further studies on these characters, their training, professional activity and participation in the construction of discourses and practices of intervention about the city and its buildings, discussing individual and grouped interests that were left behind.
124

Uma proposta de solu??o para funcionamento offline em aplica??es android

Guedes, Jean Guerethes Fernandes 28 August 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:02:52Z No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-26T23:20:34Z (GMT) No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) / Made available in DSpace on 2016-07-26T23:20:34Z (GMT). No. of bitstreams: 1 JeanGuerethesFernandesGuedes_DISSERT.pdf: 3398698 bytes, checksum: 6e847e280c1fe33f04641aa4bc1758db (MD5) Previous issue date: 2015-08-28 / Diante da crescente demanda pela cria??o de aplicativos m?veis, impulsionada pelo usocada vez mais frequente de smartphones e tablets, cresceu na sociedade a necessidade poracesso a dados remotos de forma integral na utiliza??o do aplicativo m?vel em ambientessem conectividade, em que n?o h? disponibiliza??o de acesso ? rede em todos os momentos.Diante dessa realidade, esse trabalho teve como objetivo o desenvolvimento de uma solu??oatrav?s de um framework, que apresente como principais fun??es o provimento de ummecanismo de persist?ncia, replica??o e sincroniza??o dos dados, contemplando a cria??o,remo??o, atualiza??o e visualiza??o dos dados persistidos ou requisitados, mesmo estandoo dispositivo m?vel sem conectividade com a rede. Do ponto de vista das pr?ticas deprograma??o e arquitetura, isso reflete em definir estrat?gias para persist?ncia de dadoslocal, replica??o e sincroniza??o de dados. Atrav?s de um estudo controlado foi poss?velvalidar a solu??o proposta, sendo constatado ganhos como a redu??o na quantidade delinhas de c?digo e de quantidade de tempo necess?rios para realizar o desenvolvimento deum aplicativo sem que houvesse aumento significativo para a realiza??o das opera??es. / Given the growing demand for the development of mobile applications, driven by use increasingly common in smartphones and tablets grew in society the need for remote data access in full in the use of mobile application without connectivity environments where there is no provision network access at all times. Given this reality, this work proposes a framework that present main functions are the provision of a persistence mechanism, replication and data synchronization, contemplating the creation, deletion, update and display persisted or requested data, even though the mobile device without connectivity with the network. From the point of view of the architecture and programming practices, it reflected in defining strategies for the main functions of the framework are met. Through a controlled study was to validate the solution proposal, being found as the gains in reducing the number of lines code and the amount of time required to perform the development of an application without there being significant increase for the operations.
125

Fatores que influenciam a fidelidade dos clientes em postos de combust?veis da cidade de Natal/RN

Mello, Luciana Torres Correia de 06 December 2013 (has links)
Made available in DSpace on 2014-12-17T14:53:18Z (GMT). No. of bitstreams: 1 LucianaTCM_DISSERT.pdf: 2651795 bytes, checksum: 7c2c35dffa683db2b43fb59f0a6f1b0e (MD5) Previous issue date: 2013-12-06 / The customer loyalty became strategy factor for the sustainability of business enterprises. And will be them competitive is important to describe the factors than the consumers consider for to choose the business than will buy the product or service. The dissertation objective is to know the factors that influence the consumer s satisfaction and loyalty in gas stations of Natal/RN, using the index national of customer satisfaction. The literature review was directed for strategy concepts, service quality, satisfaction and fidelity consumer and index national of customer satisfaction. The method used was descriptive-explicative, with application of a survey, from march 15 until april 15 of 2013, with 391 consumers of gas station. In relational analysis, we considered eight constructs: quality, price, complaints, satisfaction, image, loyalty, affection and commitment calculated. For customer satisfaction, the factors that influence have resulted in fuel quality, technical skills of vendors and duration of service. For customer loyalty, the factors that influence resulted in: image, feeling for distributor flag post, location and overall satisfaction with the gas station / A fidelidade dos clientes tornou-se fator estrat?gico para a sustentabilidade do neg?cio das empresas. E para torn?-las competitivas ? importante identificar os fatores que os clientes levam em considera??o para escolher a empresa em que ir?o comprar o produto/servi?o. Esta disserta??o de mestrado objetiva conhecer os fatores que influenciam a satisfa??o e fidelidade dos clientes em postos de combust?veis de Natal/RN, tomando como base o modelo noruegu?s de ?ndice de satisfa??o do consumidor. A pesquisa te?rica foi fundamentada nos conceitos de estrat?gia, qualidade nos servi?os, satisfa??o e fidelidade do cliente e especificamente nos ?ndices nacionais de satisfa??o do cliente. O m?todo utilizado foi descritivo-explicativo, com aplica??o de uma pesquisa do tipo survey, no per?odo de 15 de mar?o ? 15 de abril de 2013, com 391 clientes de postos de combust?veis. Foram considerados na an?lise relacional oito constructos: qualidade, pre?o, reclama??o, satisfa??o, imagem, fidelidade, afetividade e compromisso calculado. Para a satisfa??o dos clientes, os fatores que influenciam resultaram em: qualidade do combust?vel; habilidades t?cnicas dos vendedores e tempo de atendimento. Para a fidelidade do cliente, os fatores que influenciaram resultaram em: imagem, sentimento em rela??o a bandeira distribuidora, localiza??o do posto e satisfa??o geral com o posto
126

Uma abordagem comportamental para inser??o de rob?s em ambientes culturais

Antunes, Viviane Andr? 22 December 2004 (has links)
Made available in DSpace on 2014-12-17T14:55:32Z (GMT). No. of bitstreams: 1 VivianeAA_pag47_ate_pag74.pdf: 8458101 bytes, checksum: b6838ee89eafca0ef9837da1230e9148 (MD5) Previous issue date: 2004-12-22 / In this work, we propose methodologies and computer tools to insert robots in cultural environments. The basic idea is to have a robot in a real context (a cultural space) that can represent an user connected to the system through Internet (visitor avatar in the real space) and that the robot also have its representation in a Mixed Reality space (robot avatar in the virtual space). In this way, robot and avatar are not simply real and virtual objects. They play a more important role in the scenery, interfering in the process and taking decisions. In order to have this service running, we developed a module composed by a robot, communication tools and ways to provide integration of these with the virtual environment. As welI we implemented a set of behaviors with the purpose of controlling the robot in the real space. We studied available software and hardware tools for the robotics platform used in the experiments, as welI we developed test routines to determine their potentialities. Finally, we studied the behavior-based control model, we planned and implemented alI the necessary behaviors for the robot integration to the real and virtual cultural spaces. Several experiments were conducted, in order to validate the developed methodologies and tools / Neste trabalho, propomos metodologias e ferramentas computacionais visando inserir rob?s em ambientes culturais. O objetivo ? que um rob? localizado em um contexto real (espa?o cultural) possa representar tanto um usu?rio conectado ao sistema via Internet (avatar real para o visitante virtual), como tamb?m ter seu avatar em um ambiente de Realidade Mista (avatar para o rob? no ambiente virtual). Nesse sentido, o rob? e seu avatar deixam de ser meros objetos, real e virtual, e passam a ter uma fun??o mais importante no cen?rio, podendo interferir no processo e tomar decis?es. Para que esse servi?o possa ser disponibilizado, desenvolvemos um m?dulo composto por um rob?, ferramentas de comunica??o e provemos maneiras de realizar a integra??o entre este e o ambiente virtual, bem como implementamos um conjunto de comportamentos com a finalidade de controle do prot?tipo no seu ambiente real. Estudamos ferramentas de software e Hardware dispon?veis para a plataforma rob?tica usada nos experimentos, bem como desenvolvemos rotinas de testes para determinar suas potencialidades. Ainda, estudamos o modelo de controle baseado em comportamentos, planejamos e implementamos todos os comportamentos necess?rios ? integra??o do rob? aos ambientes real e virtual. V?rios experimentos foram realizados para valida??o das metodologias e ferramentas desenvolvidas, permitindo concluir que as mesmas atendem de forma satisfat?ria ao prop?sito inicial para o qual foram desenvolvidas
127

Controle din?mico de rob?s m?veis com acionamento diferencial

Vieira, Frederico Carvalho 03 February 2006 (has links)
Made available in DSpace on 2014-12-17T14:56:02Z (GMT). No. of bitstreams: 1 FredericoCV.pdf: 1331103 bytes, checksum: ada41c7da2fcc7a89d6ae45f8758a676 (MD5) Previous issue date: 2006-02-03 / This work addresses the dynamic control problem of two-wheeled differentially driven non-holonomic mobile robot. Strategies for robot positioning control and robot orientating control are presented. Such strategies just require information about the robot con?guration (x, y and teta), which can be collected by an absolute positioning system. The strategies development is related to a change on the controlled variables for such systems, from x, y and teta to s (denoting the robot linear displacement) and teta, and makes use of the polar coordinates representation for the robot kinematic model. Thus, it is possible to obtain a linear representation for the mobile robot dynamic model and to develop such strategies. It is also presented that such strategies allow the use of linear controllers to solve the control problem. It is shown that there is flexibility to choice the linear controller (P, PI, PID, Model Matching techniques, others) to be implemented. This work presents an introduction to mobile robotics and their characteristics followed by the control strategies development and controllers design. Finally, simulated and experimental results are presented and commented / Esta disserta??o trata do problema de controle din?mico de rob?s m?veis n?o-holon?micos com duas rodas e acionamento diferencial. S?o apresentadas estrat?gias para controle de posi??o e de orienta??o de rob?s com as caracter?sticas citadas, baseadas apenas em informa??es de configura??o do rob? (posi??o e orienta??o no espa?o cartesiano x, y e teta), coletadas a partir de um sistema de posicionamento absoluto. O desenvolvimento da estrat?gia est? associado a uma mudan?a nas vari?veis controladas do rob?, de x, y e teta para s (representando o deslocamento linear do rob?) e teta, e na representa??o em coordenadas polares do modelo cinem?tico do rob?. Desta forma, consegue-se uma representa??o linear para o modelo din?mico do rob?, a partir da qual s?o propostas as estrat?gias de controle. Com as estrat?gias definidas, mostra-se que ? poss?vel implementar controladores din?micos lineares para permitir a estabiliza??o do sistema rob?tico. As estrat?gias apresentadas tamb?m fornecem flexibilidade com rela??o ? escolha do tipo de controlador din?mico (P, PI, PID, t?cnica Model Matching, entre outros) a ser utilizado. Esta disserta??o apresenta uma introdu??o ? rob?tica m?vel e ?s caracter?sticas do tipo de sistema abordado, seguindo para uma revis?o bibliogr?fica, desenvolvimento das estrat?gias de controle e projeto dos controladores. Finalmente, s?o apresentados e discutidos resultados obtidos atrav?s de simula??es e resultados experimentais
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An?lise de desempenho de um fog?o solar com parabola fabricada em material comp?sito

Macedo Neto, Miguel Cabral de 30 May 2011 (has links)
Made available in DSpace on 2014-12-17T14:58:07Z (GMT). No. of bitstreams: 1 MiguelCMN_DISSERT.pdf: 16186905 bytes, checksum: 2eff0d12f0947aff6c9902b788587ee5 (MD5) Previous issue date: 2011-05-30 / It is presented a solar cooker made with a parabolic reflector composed by a composite material. For this purpose, it was utilized a cast concrete with a parabolic profile obtained by means of modeling. It will be demonstrated the manufacturing process and settings, as well as tests results, in order to determine the contact temperature and cooking time of some foods. This solar cooker presents the following main characteristics: the concentration method, low cost and easy manufacturing process. It was performed by employing recycled materials such as cement, plaster, crushed polystyrene and wheels. The captation area measures 1 square meter and its parabole was covered with a mirrors measuring 25 cm2. A temperature higher than 650?C was obtained. Furthermore, it has been demonstrated that the cooking viability for several type of foods such as beans, potatoes, rice, yams and pasta can be used in two meals for a family of four. In addition, the advantages of this cooker were analysed in comparison with others described in literature as well as those operating on gas. Especially in Northeast of Brazil, where there is a potential for solar energy, this prototype is an important tool, because it avoids not only desertification, but also pollutants from burning firewoods which cause ecological imbalance / Apresenta-se um fog?o solar a concentra??o com par?bola refletora constru?da com um material comp?sito. Foi utilizado um molde de concreto com perfil parab?lico obtido atrav?s da modelagem. Ser?o apresentados os processos de fabrica??o e montagem bem como os resultados de testes para determinar a temperatura de contacto e os tempos de cozedura de certos tipos de alimentos. O fog?o solar a concentra??o tem como principal caracter?stica seu custo baixo, sendo produzidos a partir de uma composi??o de materiais reutiliz?veis, como cimento, gesso e EPS triturado e pneus. Apresenta ?rea de capta??o de 1,0 metro quadrado e sua par?bola foi coberto com segmentos de espelhos de 25 cm?. As principais carracter?sticas do fog?o solar ? concentra??o propostas s?o seus f?ceis processos de fabrica??o, montagem e seu baixo custo. Obteve-se temperatura de foco superioor a 650?C. Demonstrou-se a viabilidade de coc??o desse fog?o solar para v?rios tipo de alimentos como feij?o, batata, arroz, inhame e macarr?o e podendo ser usado em duas refei??es para uma fam?lia de quatro pessoas. A competitividade do fog?o solar estudado com outros apontados pela literatura solar para coc??o de alimentos e at? mesmo com o fog?o a g?s para excelentes condi??es solarim?tricas. Este prot?tipo pode representar uma importante contribui??o para o uso de fog?es solares, especialmente no Nordeste, para o combate ? desertifica??o, e emiss?o de poluentes pelo uso massivo de lenha, que causa desequil?brio ecol?gico nessa regi?o
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Viabilidade de utiliza??o de um comp?sito de matriz cer?mica com cargas recicl?veis na fabrica??o de equipamentos solares

Mota, Maria Kalionara de Freitas 08 February 2012 (has links)
Made available in DSpace on 2014-12-17T14:58:14Z (GMT). No. of bitstreams: 1 MariaKFM_DISSERT.pdf: 4478017 bytes, checksum: bb7d18f11901c25f02491e8c88ba1ff2 (MD5) Previous issue date: 2012-02-08 / Composite materials can be defined as materials formed from two or more constituents with different compositions, structures and properties, which are separated by an interface. The main objective in producing composites is to combine different materials to produce a single device with superior properties to the component unit. The present study used a composite consisting of plaster, cement, EPS, tire, PET and water to build prototype solar attempt to reduce the manufacturing cost of such equipment. It was built two box type solar cookers, a cooler to be cooled by solar energy, a solar dryer and a solar cooker concentration. For these prototypes were discussed the processes of construction and assembly, determination of thermal and mechanical properties, and raising the performance of such solar systems. Were also determined the proportions of the constituents of the composite materials according to specific performance of each prototype designed. This compound proved to be feasible for the manufacture of such equipment, low cost and easy manufacturing and assembly processes / Foi concebido e estudado um comp?sito de matriz cer?mica composto por gesso, cimento, EPS, pneu, PET e ?gua para construir prot?tipos solares competitivos em efici?ncia com outros equipamentos de materiais convencionais j? constru?dos e estudados e de menor custo de fabrica??o. Foram constru?dos dois fornos/fog?es solares tipo caixa, uma caixa t?rmica para ser refrigerada por energia solar, um secador solar e um fog?o solar a concentra??o. Foram determinadas as propor??es dos materiais constituintes do comp?sito em fun??o das especificidades de desempenho de cada prot?tipo projetado e de resultados alcan?ados pelos prot?tipos anteriormente estudados. Foram abordados os processos de constru??o e montagem de tais equipamentos e determinadas propriedades t?rmicas e mec?nicas. Avaliou-se tamb?m o desempenho de cada prot?tipo constru?do. Esse comp?sito mostrou-se vi?vel para fabrica??o de tais equipamentos, com baixo custo e f?ceis processos de fabrica??o e montagem
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Otimiza??o de sistema de bombeamento com energia e?lica: sistema de bombeamento de S?o Gabriel/BA

Bruni, Carlos D?alexandria 24 January 2007 (has links)
Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1 CarlosAB.pdf: 1249717 bytes, checksum: c205c3ac7994f2c6d8251901cda8facb (MD5) Previous issue date: 2007-01-24 / After the Protocol of Kyoto and of the ECHO 92 - Rio de Janeiro, the attentions of the world focus to the preservation of the environment and of the maintainable use of the natural resources. People were looking for preserving environment for the future generations. Ever since, solutions are looked for the supply of energy in its more acquaintances forms and the substitution of the use of fossil fuels for the such alternative forms as: Photovoltaics, solar heat systems for water, wind , bio-diesel, etc. and in this context the Company of Engineering of the State of Bahia - Cerb changed a diesel pumping system by an wind one, It?s the first community system of this nature in Bahia. Facing problems with the model, a Cerb involved the academic segment of the Federal Center of Technological Education of Bahia Cefetba looking for a solution. This work intends to demonstrate the possibilities of optimization of the pumping communit system that supply water to approximately 50 people in the place of Rom?o, municipal district of S?o Gabriel-Ba. Technical reports were published in AGRENERGD2004-Unicamp SP and Scientific Magazine ETC,Cefetba, 2005. A simulation of the increase of energy is presented for heights of 15 and 20m, considering the eletromecanical balance from the pumping energy to the wind turbine. From the accomplished bibliographical revision, we emphasized the mechanical aspects of the engineering once in UFRN, those studies concentrate on the Department of Mechanical Engineering while, in others eletroelectronic are more emphasized. Finally, documents that we judged important were enclosed for the perfect understanding of this work / A partir do Protocolo de Kyoto e da ECO 92- Rio de Janeiro, as aten??es do mundo est?o voltadas para a preserva??o do meio ambiente e do uso sustent?vel dos recursos naturais, preservando-os para as gera??es futuras. Desde ent?o, buscam-se solu??es para o suprimento de energia nas suas mais conhecidas formas e a substitui??o do uso de combust?veis f?sseis pelas formas alternativas tais como solar fotovoltaica, termo-solar, e?lica, bio-diesel, etc. e neste contexto a Companhia de Engenharia do Estado da Bahia (Cerb) substituiu um sistema de bombeamento com moto-bomba a ?leo diesel por um sistema de bombeamento com energia e?lica, primeiro sistema coletivo desta natureza. Diante dos problemas surgidos, partiu-se para a solu??o envolvendo o segmento acad?mico do Centro Federal de Educa??o Tecnol?gica da Bahia Cefet-BA. Este trabalho pretende demonstrar as possibilidades de otimiza??o do sistema de bombeamento comunit?rio que atende aproximadamente 50 pessoas na localidade de Rom?o, munic?pio de S?o Gabriel-Ba, tendo seus relat?rios t?cnicos publicados no AGRENERGD2004-Unicamp SP e Revista Cient?fica ETC, Cefet-BA, 005. ? apresentada uma simula??o da disponibilidade energ?tica para alturas de 15m e 20m, considerando o balan?o eletromec?nico desde o bombeamento at? o conversor e?lico. Da revis?o bibliogr?fica realizada, optou-se pela ?nfase aos aspectos mec?nicos da engenharia uma vez que na UFRN, esses estudos se concentram no Departamento de Engenharia Mec?nica enquanto que, em outras, os aspectos eletro-eletr?nicos s?o mais enfatizados. Finalmente, foram anexados documentos considerados importantes para a perfeita compreens?o deste trabalho

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