Made available in DSpace on 2014-12-17T14:34:43Z (GMT). No. of bitstreams: 1 JohnatanRSB_DISSERT.pdf: 3910794 bytes, checksum: 43d57ca72250e58dc10b9d5c0f6f4a53 (MD5) Previous issue date: 2011-12-06 / The Brazilian tax structure has specific characteristics and the performance level of government. The autonomy given to municipalities to manage their activities after the 1988 Constitution, made them highly dependent on intergovernmental transfers of resources, revealing the fragility of the administrative capacity of these entities. The vertical gap revealed by the constitutional structure of the Brazilian fiscal federalism model contributes to the formation of this specific feature that you are eroding the tax base and the ability of municipal own revenues. Although there was a better regulation of these transfers after the enactment of the Fiscal Responsibility Law, it is observed that the amount of resources transferred to the municipalities of Rio Grande do Norte is very high and is the main source of revenue of municipalities. In light of the theory of federalism and fiscal decentralization, in particular, the theories related to intergovernmental transfers, we seek to diagnose the transfers from the systematization of information on the origin, destination and value. We used the econometric model of System Dynamic Panel GMM in making the diagnosis and verification of the impact of transfers on public finances of the municipalities of the newborn, associated with a review in light of the theory of fiscal federalism and intergovernmental transfers. The paper presents some proposals for the transfer system and the composition of spending in order to contribute to greater tax efficiency / A estrutura fiscal brasileira apresenta caracter?sticas espec?ficas quanto ? atua??o das esferas de governo. A autonomia dada aos munic?pios para a gest?o de suas atividades, ap?s a constitui??o de 1988, os tornou altamente dependentes das transfer?ncias intergovernamentais de recursos, revelando a fragilidade da capacidade administrativa destes entes. A brecha vertical revelada pela estrutura constitucional do modelo de federalismo fiscal brasileiro contribui para a forma??o dessa caracter?stica espec?fica que acaba minando a base tribut?ria municipal e a capacidade de arrecada??o pr?pria. Embora tenha havido uma melhor regulamenta??o dessas transfer?ncias ap?s a promulga??o da Lei de Responsabilidade Fiscal, observa-se que a quantidade de recursos transferidos aos munic?pios do Rio Grande do Norte ? bastante elevada e constitui a principal fonte de receita desses munic?pios. ? luz da teoria do federalismo e descentraliza??o fiscal e, em particular, nas teorias relacionadas com as transfer?ncias intergovernamentais, busca-se diagnosticar as transfer?ncias a partir da sistematiza??o das informa??es quanto ? origem, o valor e o destino. Utilizou-se o modelo econom?trico de Painel Din?mico System GMM na elabora??o do diagn?stico e na verifica??o do impacto dessas transfer?ncias nas finan?as p?blicas dos munic?pios do RN, associado a uma an?lise ? luz da teoria de federalismo fiscal e das transfer?ncias intergovernamentais. O trabalho apresenta algumas proposi??es para o sistema de transfer?ncias e na composi??o dos gastos a fim de contribuir com uma maior efici?ncia fiscal

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-03T23:16:48Z No. of bitstreams: 1 AnaFlaviaLinsSouto_DISSERT.pdf: 1191835 bytes, checksum: f7fea5d276f29ff8f41cd847fd02f335 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-09T22:31:31Z (GMT) No. of bitstreams: 1 AnaFlaviaLinsSouto_DISSERT.pdf: 1191835 bytes, checksum: f7fea5d276f29ff8f41cd847fd02f335 (MD5) / Made available in DSpace on 2015-12-09T22:31:31Z (GMT). No. of bitstreams: 1 AnaFlaviaLinsSouto_DISSERT.pdf: 1191835 bytes, checksum: f7fea5d276f29ff8f41cd847fd02f335 (MD5) Previous issue date: 2014-11-10 / O presente trabalho tem como objetivo demonstrar a rela??o do princ?pio da efici?ncia -como expresso na Constitui??o Federal de 1988, atrav?s da Emenda Constitucional n? 19 - com as ag?ncias reguladoras, mais precisamente a ANATEL (Ag?ncia Nacional de Telecomunica??es). Abrange tamb?m a import?ncia que esse princ?pio possui sobre a regula??o - fiscalizar e gerenciar os servi?os p?blicos - e quando uma atividade ser? considerada eficiente, tendo em mente que as ag?ncias sujeitam-se aos demais princ?pios da Administra??o P?blica. O crescente uso da telefonia vem possibilitando um maior desenvolvimento de tecnologias que proporcionam melhorias na presta??o desse servi?o. O VoIP (Voice over IP), nada mais ? que um avan?o tecnol?gico que atinge diretamente as prestadoras do servi?o de telefonia convencional, tanto pela modifica??o dos neg?cios que trabalhavam por um longo per?odo com a mesma tecnologia, quanto pela quantidade de novos concorrentes que entram no mercado. Como ag?ncia reguladora do servi?o de telecomunica??es, a ANATEL, ainda n?o regulamentou o servi?o de telefonia de voz utilizando o protocolo IP. O que se aguarda com o passar dos anos ? que a ANATEL exer?a a sua fun??o regulat?ria para proporcionar melhores condi??es de competi??o entre as empresas prestadoras do VoIP e da telefonia convencional, obviamente que algumas dificuldades s?o esperadas, haja vista, que o VoIP ? uma tecnologia que abrange dois servi?os, tanto a telefonia convencional quanto a utiliza??o da internet / The present work aims to demonstrate the link of the principle of efficiency - as expressed in the Constitution of 1988, by Constitutional Amendment No. 19 - with regulatory agencies, more specifically the ANATEL (National Telecommunications Agency). It also includes this principle?s importance to regulation - to monitor and manage public services - as well as when an activity will be considered efficient, keeping in mind that agencies are subjected to other principles of public administration. The increasing use of telephony has enabled further development of technologies that provide improvements in the provision of this service. The VoIP (Voice over IP), is nothing more than a technological breakthrough that directly targets the providers of conventional telephone service, both by modifying the business working for a long time with the same technology as the amount of new competitors? dispute on market share. It also analyses the difficulty of understanding and definition of what is VoIP telephony, its growth and the threats that the traditional and mostly which is ANATEL?s role concerning this telephony technology. As regulator of the telecommunications service, ANATEL not yet regulated the voice telephony service using the IP protocol. What looks over the years is that ANATEL exercise its regulatory function to provide better conditions for competition among providers of VoIP and traditional telephone companies, obviously some difficulties are expected, given that VoIP is a technology that provides two services, through conventional telephony and using the internet.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-22T21:52:17Z No. of bitstreams: 1 ItaloAugustoSouzaDeAssis_DISSERT.pdf: 2067503 bytes, checksum: 774040a098f0200527ecd35e1ac92443 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-24T00:08:09Z (GMT) No. of bitstreams: 1 ItaloAugustoSouzaDeAssis_DISSERT.pdf: 2067503 bytes, checksum: 774040a098f0200527ecd35e1ac92443 (MD5) / Made available in DSpace on 2016-02-24T00:08:09Z (GMT). No. of bitstreams: 1 ItaloAugustoSouzaDeAssis_DISSERT.pdf: 2067503 bytes, checksum: 774040a098f0200527ecd35e1ac92443 (MD5) Previous issue date: 2015-01-30 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / O algoritmo de migra??o reversa no tempo (RTM) tem sido amplamente utilizado na ind?stria s?smica para gerar imagens do subsolo e, assim, reduzir os riscos de explora??o de petr?leo e g?s. Seu uso em larga escala ? devido a sua alta qualidade no imageamento do subsolo. O RTM ? tamb?m conhecido pelo seu alto custo computacional. Por essa raz?o, t?cnicas de computa??o paralela t?m sido utilizadas em suas implementa??es. Em geral, as abordagens paralelas para o RTM utilizam uma granularidade grossa, dividindo o processamento de um subconjunto de tiros s?smicos entre n?s de sistemas distribu?- dos. A abordagem paralela com granularidade grossa para o RTM tem se mostrado bastante eficiente uma vez que o processamento de cada tiro s?smico pode ser realizado de forma independente. Todavia, os n?s dos sistemas distribu?dos atuais s?o, em geral, equipamentos com diversos elementos de processamento sob uma arquitetura com mem?ria compartilhada. Assim, o desempenho do algoritmo de RTM pode ser consideravelmente melhorado com a utiliza??o de uma abordagem paralela com granularidade fina para o processamento designado a cada n?. Por essa raz?o, este trabalho apresenta um algoritmo paralelo eficiente de migra??o reversa no tempo em 3D com granularidade fina utilizando o padr?o OpenMP como modelo de programa??o. O algoritmo de propaga??o da onda ac?stica 3D comp?e grande parte do RTM. Foram analisados diferentes balanceamentos de carga a fim de minimizar poss?veis perdas de desempenho paralelo nesta fase. Os resultados encontrados serviram como base para a implementa??o das outras fases do RTM: a retropropaga??o e a condi??o de imagem. O algoritmo proposto foi testado com dados sint?ticos representando algumas das poss?veis estruturas do subsolo. M?tricas como speedup e efici?ncia foram utilizadas para analisar seu desempenho paralelo. As se??es migradas mostram que o algoritmo obteve um desempenho satisfat?rio na identifica??o das estruturas da subsuperf?cie. J? as an?lises de desempenho paralelo explicitam a escalabilidade dos algoritmos alcan?ando um speedup de 22,46 para a propaga??o da onda e 16,95 para o RTM, ambos com 24 threads. / The reverse time migration algorithm (RTM) has been widely used in the seismic industry to generate images of the underground and thus reduce the risk of oil and gas exploration. Its widespread use is due to its high quality in underground imaging. The RTM is also known for its high computational cost. Therefore, parallel computing techniques have been used in their implementations. In general, parallel approaches for RTM use a coarse granularity by distributing the processing of a subset of seismic shots among nodes of distributed systems. Parallel approaches with coarse granularity for RTM have been shown to be very efficient since the processing of each seismic shot can be performed independently. For this reason, RTM algorithm performance can be considerably improved by using a parallel approach with finer granularity for the processing assigned to each node. This work presents an efficient parallel algorithm for 3D reverse time migration with fine granularity using OpenMP. The propagation algorithm of 3D acoustic wave makes up much of the RTM. Different load balancing were analyzed in order to minimize possible losses parallel performance at this stage. The results served as a basis for the implementation of other phases RTM: backpropagation and imaging condition. The proposed algorithm was tested with synthetic data representing some of the possible underground structures. Metrics such as speedup and efficiency were used to analyze its parallel performance. The migrated sections show that the algorithm obtained satisfactory performance in identifying subsurface structures. As for the parallel performance, the analysis clearly demonstrate the scalability of the algorithm achieving a speedup of 22.46 for the propagation of the wave and 16.95 for the RTM, both with 24 threads.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-03T22:56:48Z No. of bitstreams: 1 FelipeDenisMendoncaDeOliveira_TESE.pdf: 5762435 bytes, checksum: f710387481b7dc41c1ff916b28138dbf (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-05-05T19:51:58Z (GMT) No. of bitstreams: 1 FelipeDenisMendoncaDeOliveira_TESE.pdf: 5762435 bytes, checksum: f710387481b7dc41c1ff916b28138dbf (MD5) / Made available in DSpace on 2016-05-05T19:51:58Z (GMT). No. of bitstreams: 1 FelipeDenisMendoncaDeOliveira_TESE.pdf: 5762435 bytes, checksum: f710387481b7dc41c1ff916b28138dbf (MD5) Previous issue date: 2015-08-03 / Uma Rede de Sensores sem Fio (RSSF) consiste de dispositivos distribu?dos em uma ?rea com a finalidade de monitorar vari?veis f?sicas, tais como temperatura, press?o, vibra??o, movimento e condi??es ambientais em locais onde as redes cabeadas seriam complicadas ou impratic?veis de serem implementadas, por exemplo, aplica??es industriais de dif?cil acesso, monitoramento e controle de po?os petrol?feros terrestres ou mar?timos, no acompanhamento de extensas ?reas de cultivo agr?rio e animal, entre outros. Para ser vi?vel, uma RSSF deve possuir requisitos importantes, tais como baixo custo, baixa lat?ncia e, principalmente, baixo consumo de energia. Entretanto, para garantir tais requisitos, essas redes sofrem limita??o de recursos, al?m de, eventualmente, serem utilizadas em ambientes hostis, levando a altas taxas de falhas, tais como roteamentos segmentados, perda de mensagens, reduzindo a efici?ncia podendo chegar, inclusive, a comprometer a rede como um todo. Este trabalho tem por objetivo apresentar o FTE-LEACH, um protocolo de roteamento energeticamente eficiente e tolerante a falhas, mantendo a efici?ncia na comunica??o e na dissemina??o de dados. Tal protocolo foi desenvolvido baseado no padr?o IEEE 802.15.4 e voltado ?s redes industriais com recursos energ?ticos limitados. / A Wireless Sensor Network (WSN) consists of distributed devices in an area in order to monitor physical variables such as temperature, pressure, vibration, motion and environmental conditions in places where wired networks would be difficult or impractical to implement, for example, industrial applications of difficult access, monitoring and control of oil wells on-shore or off-shore, monitoring of large areas of agricultural and animal farming, among others. To be viable, a WSN should have important requirements such as low cost, low latency, and especially low power consumption. However, to ensure these requirements, these networks suffer from limited resources, and eventually being used in hostile environments, leading to high failure rates, such as segmented routing, mes sage loss, reducing efficiency, and compromising the entire network, inclusive. This work aims to present the FTE-LEACH, a fault tolerant and energy efficient routing protocol that maintains efficiency in communication and dissemination of data.This protocol was developed based on the IEEE 802.15.4 standard and suitable for industrial networks with limited energy resources

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T23:14:12Z No. of bitstreams: 1 RomuloAlvesDeOliveira_TESE.pdf: 1869244 bytes, checksum: af0453c8083aee85607b79c3a17c1d4c (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T22:30:48Z (GMT) No. of bitstreams: 1 RomuloAlvesDeOliveira_TESE.pdf: 1869244 bytes, checksum: af0453c8083aee85607b79c3a17c1d4c (MD5) / Made available in DSpace on 2016-06-01T22:30:48Z (GMT). No. of bitstreams: 1 RomuloAlvesDeOliveira_TESE.pdf: 1869244 bytes, checksum: af0453c8083aee85607b79c3a17c1d4c (MD5) Previous issue date: 2015-01-27 / Atualmente os projetos de Ilumina??o P?blica (IP), ou seja, ruas, avenidas, pra?as, estacionamentos e similares s?o realizados com a utiliza??o de softwares comerciais ou livres, em geral, fornecidos por fabricantes ou grupos de fabricantes de produtos de ilumina??o, aplicando o M?todo Ponto a Ponto para o c?lculo dos n?veis de ilumina??o. Outros pontos em comum s?o: a falta de preocupa??o na redu??o dos custos dos projetos e a dificuldade em modificar as estruturas utilizadas, tais como: localiza??o e altura dos postes e lumin?rias, ?ngulo de inclina??o das lumin?rias, quantidade de lumin?rias por poste, entre outros. Qualquer altera??o nas estruturas ter? que ser feita manualmente, geralmente em um ambiente CAD, para depois obter os novos resultados e comparar com os anteriores. Para auxiliar nessa tarefa, ? proposta aqui a utiliza??o da Metaheur?stica Col?nia de Formigas, onde os par?metros e localiza??o das estruturas passam a ser definidos automaticamente, de forma a atender os n?veis de ilumina??o estabelecidos nas normas t?cnicas, al?m de otimizar o custo de material por unidade de ?rea. / The development of public lighting projects in Brazil must meet the standards established in Brazilian standards. Many of these projects is developed through the use of knowledge about "practical rules" practiced by the designers of this area. In some cases are also used computational tools offered, generally, by leading manufacturers of lamps/luminaires. These tools have served only as calculation tools, with some limitations, such as: are not able to verify compliance or not the parameters established by Brazilian standards, most of the luminaires offered in your database are not sold in Brazil, not have no concern about the analysis of the implementation costs of elaborate designs and, finally, present an enormous difficulty in performing tests on a large volume of possible projects. It is the goal of this thesis to develop a methodology and a computational tool for the development of public lighting projects based on genetic algorithm techniques that not only perform the calculations of these projects, but can also test several possible projects using in your database the luminaires marketed in Brazil, providing the user, as a solution, a set of projects that meet the Brazilian standards and classified according the implementation costs of each project. To adjust the proposed algorithm the following performance parameters were modified: number of individuals in the initial population; probability of achievement of the cross-over; probability of achievement of the mutation. A comparison of this method with the projects developed with the use of "practical rules" is performed for various types of existing roads. The results obtained using the proposed methodology and the developed computational tool show that the methodology, including the adjustments in performance parameters, is able to meet the objectives of the work.

Made available in DSpace on 2014-12-17T14:56:01Z (GMT). No. of bitstreams: 1 JoseKCO_DISSERT.pdf: 2360607 bytes, checksum: ad43aaed1b6651cd3d8e3ffe4e2f5b67 (MD5) Previous issue date: 2012-05-04 / The sanitation companies from Brazil has a great challenge for the XXI century: seek to mitigate the rate of physical waste (water, chemicals and electricity) and financial waste caused by inefficient operating systems drinking water supply, considering that currently we already face, in some cases, the scarcity of water resources. The supply systems are increasingly complex as they seek to minimize waste and at the same time better serve the growing number of users. However, this technological change is to reduce the complexity of the challenges posed by the need to include users with higher quality and efficiency in services. A major challenge for companies of water supplies is to provide a good quality service contemplating reducing expenditure on electricity. In this situation we developed a research by a method that seeks to control the pressure of the distribution systems that do not have the tank in your setup and the water comes out of the well directly to the distribution system. The method of pressure control (intelligent control) uses fuzzy logic to eliminate the waste of electricity and the leaks from the production of pumps that inject directly into the distribution system, which causes waste of energy when the consumption of households is reduced causing the saturation of the distribution system. This study was conducted at Green Club II condominium, located in the city of Parnamirim, state of Rio Grande do Norte, in order to study the pressure behavior of the output of the pump that injects water directly into the distribution system. The study was only possible because of the need we had to find a solution to some leaks in the existing distribution system and the extensions of the respective condominium residences, which sparked interest in developing a job in order to carry out the experiments contained in this research / As empresas de saneamento do Brasil t?m um grande desafio para o s?culo XXI, procurar diminuir o ?ndice de desperd?cios f?sicos (?gua, produtos qu?micos e energia el?trica) e financeiros causados pela inefici?ncia operacional dos sistemas de abastecimento de ?gua pot?vel, levando-se em considera??o que atualmente j? se enfrenta, em alguns casos, a escassez dos recursos h?dricos. Os sistemas de abastecimento est?o cada vez mais complexos porque buscam minimizar os desperd?cios e ao mesmo tempo atender melhor ao crescente n?mero de usu?rios. Contudo, a evolu??o tecnol?gica est? presente para diminuir a complexidade dos desafios hora impostos pela necessidade de contemplar os usu?rios com maior qualidade e efici?ncia nos servi?os. Um dos grandes desafios para as empresas de abastecimento de ?gua est? em proporcionar um servi?o de boa qualidade contemplando a diminui??o das despesas com energia el?trica. Diante disso, desenvolveu-se um trabalho de pesquisa atrav?s de um m?todo que busca controlar a press?o da rede de distribui??o em sistemas que n?o apresentam na sua configura??o o reservat?rio e, por isso a ?gua sai do po?o diretamente para a rede de distribui??o. O m?todo de controle da press?o (controle inteligente) utiliza a l?gica fuzzy para eliminar o desperd?cio de energia el?trica e os vazamentos provocados pela produ??o das bombas que injetam diretamente na rede de distribui??o, provocando desperd?cio de energia quando o consumo das resid?ncias ? reduzido causando o saturamento da rede. Esse trabalho foi realizado no condom?nio Green Club II, situado na cidade de Parnamirim - RN, com o objetivo de estudar o comportamento da press?o da bomba que injeta diretamente na rede de distribui??o. O estudo s? foi poss?vel em virtude da necessidade que havia de se encontrar uma solu??o para alguns vazamentos existentes na rede de distribui??o e nos ramais das resid?ncias do respectivo condom?nio, fato que despertou o interesse em desenvolver um trabalho com o intuito de realizar as experi?ncias contidas nesta pesquisa

Made available in DSpace on 2014-12-17T14:56:13Z (GMT). No. of bitstreams: 1 KayoGS_DISSERT.pdf: 4975392 bytes, checksum: 5d113169a6356e5e7704aec116237caf (MD5) Previous issue date: 2013-03-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This paper analyzes the performance of a parallel implementation of Coupled Simulated Annealing (CSA) for the unconstrained optimization of continuous variables problems. Parallel processing is an efficient form of information processing with emphasis on exploration of simultaneous events in the execution of software. It arises primarily due to high computational performance demands, and the difficulty in increasing the speed of a single processing core. Despite multicore processors being easily found nowadays, several algorithms are not yet suitable for running on parallel architectures. The algorithm is characterized by a group of Simulated Annealing (SA) optimizers working together on refining the solution. Each SA optimizer runs on a single thread executed by different processors. In the analysis of parallel performance and scalability, these metrics were investigated: the execution time; the speedup of the algorithm with respect to increasing the number of processors; and the efficient use of processing elements with respect to the increasing size of the treated problem. Furthermore, the quality of the final solution was verified. For the study, this paper proposes a parallel version of CSA and its equivalent serial version. Both algorithms were analysed on 14 benchmark functions. For each of these functions, the CSA is evaluated using 2-24 optimizers. The results obtained are shown and discussed observing the analysis of the metrics. The conclusions of the paper characterize the CSA as a good parallel algorithm, both in the quality of the solutions and the parallel scalability and parallel efficiency / O presente trabalho analisa o desempenho paralelo de uma implementa??o do Simulated Annealing Acoplado (CSA, do ingl?s Coupled Simulated Annealing) para otimiza??o de vari?veis cont?nuas sem restri??es. O processamento paralelo ? uma forma eficiente de processamento de informa??o com ?nfase na explora??o de eventos simult?neos na execu??o de um software. Ele surge principalmente devido ?s elevadas exig?ncias de desempenho computacional e ? dificuldade em aumentar a velocidade de um ?nico n?cleo de processamento. Apesar das CPUs multiprocessadas, ou processadores multicore, serem facilmente encontrados atualmente, diversos algoritmos ainda n?o s?o adequados para executar em arquiteturas paralelas. O algoritmo do CSA ? caracterizado por um grupo de otimizadores Simulated Annealing (SA) trabalhando em conjunto no refinamento da solu??o. Cada otimizador SA ? executado em uma ?nica thread, e essas executadas por diferentes processadores. Na an?lise de desempenho e escalabilidade paralela, as m?tricas investigadas foram: o tempo de execu??o; o speedup do algoritmo com respeito ao aumento do n?mero de processadores; e a efici?ncia na utiliza??o de elementos de processamento com rela??o ao aumento da inst?ncia do problema tratado. Al?m disso, foi verificada a qualidade da solu??o final. Para o estudo, esse trabalho analisa uma vers?o paralela do CSA e sua vers?o serial equivalente. Ambos algoritmos foram analisados sobre 14 fun??es de refer?ncia. Para cada uma dessas fun??es, o CSA ? avaliado utilizando de 2 a 24 otimizadores. Os resultados obtidos s?o exibidos e comentados observando-se as m?tricas de an?lise. As conclus?es do trabalho caracterizam o CSA como um bom algoritmo paralelo, seja na qualidade das solu??es como na escalabilidade e efici?ncia paralela

Made available in DSpace on 2014-12-17T14:56:16Z (GMT). No. of bitstreams: 1 RodrigoLB_DISSERT.pdf: 2422493 bytes, checksum: d216abfd7470b7951cb5443aaa1b133a (MD5) Previous issue date: 2014-01-22 / The scarcity of natural resources and the search for alternative energy sources promote a rapid change in the energy world. Among the renewable energy sources, solar energy is the most promising, presenting technology of greatest growth rate nowadays. Researchers around the world are seeking ways to facilitate their progress, developing technologies with higher efficiency and lower cost. As a contribution to global progress, this master thesis proposes the development of a strategy of maximum power tracking based on perturbation and observation method for photovoltaic systems. The proposed control strategy is based on active power balance of the system, with a reduced number of sensors. It also allows the PV system to act as a regulator of the power quality at the point of commom coupling (PCC), compensating the harmonic distortion and power factor of the current netw / A escassez dos recursos naturais e a busca por fontes de energia alternativa promovem uma r?pidamudan?a namatriz energ?tica mundial. Dentre as fontes de energia renov?veis a energia solar ? a mais promissora, visto que ela apresenta a maior taxa de crescimento na atualidade. Pesquisadores de todo o mundo t?m buscado formas de viabiliza??o do seu progresso, desenvolvendo tecnologias com maior efici?ncia e menor custo. Como forma de contribuir para o avan?o mundial, neste trabalho ? proposto o desenvolvimento de uma estrat?gia de rastreamento da m?xima pot?ncia, baseado no m?todo perturba??o e observa??o, para sistemas fotovoltaicos. A estrat?gia de controle proposta ? baseada no balan?o de pot?ncia ativa do sistema e utiliza um n?mero reduzido de sensores. Ela tamb?m permite que o sistema fotovoltaico atue como regulador da qualidade de energia no ponto de conex?o, compensando assim a distor??o harm?nica das correntes da rede e corrigindo o fator de pot?ncia. Resultados de simula??o e experimentais s?o apresentados para validar a estrat?gia proposta

Made available in DSpace on 2014-12-17T14:57:59Z (GMT). No. of bitstreams: 1 JoelNG.pdf: 2105058 bytes, checksum: 962e04f5bc007f4ee28c0e1f7973dece (MD5) Previous issue date: 2010-02-03 / The technical and economic viability of solar heating for swimming pools is unquestionable, besides there it replaces the high costs and environmental impacts of conventional supply of energy, and it improves an optimization in the pool heating uses. This work applies the principles of the greenhouse effect: advanced thermodynamics, heat retention and equalization of temperature, to optimize the solar heating equipment, reducing the area required by collectors as much as 40% (still estimated value) for commercial collectors, with minor architectural and aesthetic impacts on the environment. It features a solar heating alternative in pools, whose main characteristics: low cost, simplicity in manufacturing and assembly and a faster heating. The system consists of two collectors spiral hoses made of polyethylene with a hundred meters each, and working on a forced flow, with only one pass of the working fluid inside the coils, and is used to pump itself treatment of pool water to obtain the desired flow. One of the collectors will be exposed to direct solar radiation, and the other will be covered by a glass slide and closed laterally, so providing the greenhouse effect. The equipment will be installed in parallel and simultaneously exposed to the sun in order to obtain comparative data on their effectiveness. Will be presented results of thermal tests for this the two cases, with and without transparent cover. Will be demonstrated, by comparison, the thermal, economic and material feasibility of these systems for heating swimming pools. / A viabilidade t?cnica e econ?mica do aquecimento solar para piscinas ? inquestion?vel, al?m da substitui??o da energia el?trica convencional, de altos custos e impactos ambientais, gera uma otimiza??o do uso da piscina. Este trabalho aplica os princ?pios do efeito estufa: isola??o termodin?mica, reten??o do calor e equaliza??o da temperatura interna, busca otimizar o equipamento de aquecimento solar, reduzindo a ?rea requerida pelos coletores em at? 40% (valor ainda estimado) em rela??o aos coletores comerciais, com menores impactos est?ticos e arquitet?nicos que s?o negativos no ambiente. Apresenta um sistema solar de aquecimento alternativo em piscinas, que tem como principais caracter?sticas; baixo custo, simplicidade nos processos de fabrica??o e montagem e um aquecimento mais r?pido. O sistema ? constitu?do por dois coletores espirais constru?dos em tubos flex?veis de polietileno, com extens?o de 100 metros cada uma, e trabalha em regime de fluxo for?ado, com apenas uma passagem do fluido de trabalho no interior das espirais, e ? utilizada a pr?pria bomba de tratamento de ?gua da piscina para a obten??o do fluxo pretendido. Um dos coletores ser? exposto diretamente ? radia??o solar, e o outro ser? coberto por um lamina de vidro e fechado lateralmente, de forma propiciar o efeito estufa. Os equipamentos ser?o instalados em paralelo e expostos simultaneamente ao sol, de forma se obter dados comparativos de suas efici?ncias. Ser?o apresentados resultados t?rmicos de ensaios realizados para os dois casos, com e sem cobertura transparente. Ser?o demonstradas comparativamente, as viabilidades t?rmica, econ?mica e de materiais destes sistemas para aquecimento de piscinas.

Made available in DSpace on 2014-12-17T14:58:01Z (GMT). No. of bitstreams: 1 GeorgeCS_DISSERT.pdf: 2052095 bytes, checksum: 94bcb92ee6c4f6a8299833c1b6b33205 (MD5) Previous issue date: 2010-04-12 / New materials made from industrial wastes have been studied as an alternative to traditional fabrication processes in building and civil engineering. These materials are produced considering some issues like: cost, efficiency and reduction of nvironmental damage. Specifically in cases of materials destined to dwellings in low latitude regions, like Brazilian Northeast, efficiency is related to mechanical and thermal resistance. Thus, when thermal insulation and energetic efficiency are aimed, it s important to increase thermal resistance without depletion of mechanical properties. This research was conducted on a construction element made of two plates of cement mortar, interspersed with a plate of recycled expanded polystyrene (EPS). This component, widely known as sandwich-panel, is commonly manufactured with commercial EPS whose substitution was proposed in this study. For this purpose it was applied a detailed methodology that defines parameters to a rational batching of the elements that constitute the nucleus. Samples of recycled EPS were made in two different values of apparent specific mass (ρ = 65 kg/m?; ρ = 130 kg/m?) and submitted to the Quick-Line 30TM that is a thermophysical properties analyzer. Based on the results of thermal conductivity, thermal capacity and thermal diffusivity obtained, it was possible to assure that recycled EPS has thermal insulation characteristics that qualify it to replace commercial EPS in building and civil engineering industry / Novos materiais desenvolvidos a partir de res?duos industriais v?m sendo estudados como alternativa aos modelos tradicionalmente empregados na constru??o civil. Para desenvolvimento desses materiais s?o considerados fatores como: custo, efici?ncia e redu??o de passivo ambiental. No caso espec?fico de materiais para aplica??o em habita??es situadas em baixas latitudes, como no Nordeste do Brasil, a efici?ncia diz respeito ?s resist?ncias mec?nica e t?rmica, onde o aumento da resist?ncia t?rmica, sem comprometimento da resist?ncia mec?nica, ? desej?vel quando se buscam a isola??o t?rmica e a efici?ncia energ?tica das edifica??es. No presente trabalho s?o apresentados os resultados do estudo de um elemento construtivo composto de placas de argamassa de cimento intercaladas por placa de EPS reciclado, constituindo um painel sandu?che para emprego na ind?stria da constru??o civil. Estuda-se detalhadamente a metodologia de execu??o desses pain?is, definindo-se par?metros para dosagem racional dos materiais que comp?em o n?cleo. Foram confeccionados corpos de prova com massas espec?ficas aparentes de 65 kg/m? e 130 kg/m?. As propriedades termof?sicas dos corpos de prova foram analisadas utilizando-se o equipamento Quick-Line 30TM, que forneceu dados de condutividade t?rmica, capacidade calor?fica e difusividade t?rmica. Com base nos resultados obtidos foi poss?vel constatar as boas caracter?sticas do EPS reciclado como material termoisolante, estando esse apto ? substitui??o do EPS comercial em pain?is de constru??o