Made available in DSpace on 2014-12-17T14:55:43Z (GMT). No. of bitstreams: 1 GustavoAC__DISSERT.pdf: 2594771 bytes, checksum: b46a4c0b026ad559d9ed126acb92b471 (MD5) Previous issue date: 2010-07-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The telecommunications industry has experienced recent changes, due to increasing quest for access to digital services for data, video and multimedia, especially using the mobile phone networks. Recently in Brazil, mobile operators are upgrading their networks to third generations systems (3G) providing to users broadband services such as video conferencing, Internet, digital TV and more. These new networks that provides mobility and high data rates has allowed the development of new market concepts. Currently the market is focused on the expansion of WiMAX technology, which is gaining increasingly the market for mobile voice and data. In Brazil, the commercial interest for this technology appears to the first award of licenses in the 3.5 GHz band. In February 2003 ANATEL held the 003/2002/SPV-ANATEL bidding, where it offered blocks of frequencies in the range of 3.5 GHz. The enterprises who purchased blocks of frequency were: Embratel, Brazil Telecom (Vant), Grupo Sinos, Neovia and WKVE, each one with operations spread in some regions of Brazil. For this and other wireless communications systems are implemented effectively, many efforts have been invested in attempts to developing simulation methods for coverage prediction that is close to reality as much as possible so that they may become believers and indispensable tools to design wireless communications systems. In this work wasm developed a genetic algorithm (GA's) that is able to optimize the models for predicting propagation loss at applicable frequency range of 3.5 GHz, thus enabling an estimate of the signal closer to reality to avoid significant errors in planning and implementation a system of wireless communication / O setor de telecomunica??es vem passando por grandes transforma??es, devido ao aumento da busca por acesso a servi?os digitais de transmiss?o de dados, v?deo e multim?dia, especialmente, por meios das redes de telefonia m?vel. Recentemente, no Brasil, as operadoras de telefonia m?vel v?m atualizando suas redes para sistemas de terceira gera??o (3G) proporcionando aos usu?rios servi?os em banda larga como v?deo confer?ncia, Internet e TV digital, dentre outros. Essas novas redes que proporcionam mobilidade e elevadas taxas de transmiss?o t?m permitido o desenvolvimento de novos conceitos de mercado de servi?os. Atualmente o mercado est? voltado para a expans?o da tecnologia WiMAX, que v?m ganhando cada vez mais o mercado das comunica??es m?veis de voz e de dados. No Brasil o interesse comercial para esta tecnologia aparece com a primeira outorga de licen?as em 3,5 GHz. Em fevereiro de 2003, a ANATEL realizou a licita??o 003/2002/SPV-ANATEL, onde ofereceu blocos de frequ?ncia em 3,5 GHz. As operadoras que adquiriram os blocos de frequ?ncia foram: Embratel, Brasil Telecom (Vant), Grupo Sinos, Neovia e WKVE, cada uma com opera??es distribu?das em regi?es do Brasil. Para que esse e outros sistemas de comunica??es sem fio sejam implementados com efici?ncia, muitos esfor?os t?m sido investidos na tentativa de desenvolvimento de m?todos de simula??o, de predi??o e de cobertura que se aproximem da realidade o melhor poss?vel, de forma a que se possam tornar ferramentas fi?is e indispens?veis no planejamento dos sistemas de comunica??es sem fio. Neste trabalho, foi desenvolvido um algoritmo gen?tico (AG s) capaz de otimizar os modelos de predi??o de perda de propaga??o aplic?veis na frequ?ncia de 3,5 GHz, possibilitando dessa forma uma estimativa do sinal mais pr?xima da realidade, evitando erros significativos no planejamento e implementa??o de um sistema de comunica??o sem fio

Submitted by Luis Ricardo Andrade da Silva (lrasilva@uefs.br) on 2016-03-01T23:07:05Z No. of bitstreams: 1 Dissertacao_Filipe Torres.pdf: 3327655 bytes, checksum: a687ff94c9854a5e290b5d00055299e0 (MD5) / Made available in DSpace on 2016-03-01T23:07:05Z (GMT). No. of bitstreams: 1 Dissertacao_Filipe Torres.pdf: 3327655 bytes, checksum: a687ff94c9854a5e290b5d00055299e0 (MD5) Previous issue date: 2015-12-18 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / Cutaneous leishmaniasis affects 12 million people around the world. The main etiological agent in Brazil is Leishmania braziliensis. Its annotation is not very well characterized and have inaccurate regions because of the large number of hypothetical and putative genes. To solve this problem, we annotated the Leishmania braziliensis genome (MHOM / BR / 75 / M2904) with new algorithm and curated database by similarity. Initially, we downloaded these sequences of Leishmania braziliensis from NCBI and used GENSCAN and GLIMMER algorithms. We compared the predicted genes with SWISSPROT protein database. The comparison process was made by BLASTx and SWISS-PROT. We also used StructRNAFinder to predict the non-coding RNA, ncrna. We identified 25,539 ORF's, 4,916 genes, 735 ncRNA and 863 proteins. 94.75\% of predicted genes from Leishmania braziliensis were present on Leishmania panamensis genome (MHOM/PA/94/PSC-1). The comparison of ncrna number and proteins highlights a relation between chromosome and ncrna. All genes found were mapped and aligned to the Leishmania braziliensis genome and stored in a relational database model built in PHP 5.0 and MySQL. All data resulting of analyses in this work is available at www.leishdb.com. / A leishmaniose cut?nea afeta cerca 12 milh?es de pessoas ao redor do mundo. O principal agente etiol?gico dessa patologia no Brasil ? a Leishmania braziliensis. A anota??o dela n?o est? bem caracterizada e possui regi?es sem uma grande certeza devido ao grande n?mero de genes hipot?ticos e putativos. Para resolver esse problema,n?s reanotamos o genoma da Leishmania braziliensis (MHOM/BR/75/M2904) com novas vers?es de algoritmos e uma base de dados curada. Inicialmente, n?s baixamos e predizemos os genes com uma base de prote?nas. A compara??o foi feita porBLASTx e o banco de dados SWISS-PROT. Tamb?m utilizamos o preditor StructRNA Finder para predi??o de RNA?s n?o codificantes. Como resultado desse trabalho identificamos 25539 ORF?s, 4916 genes, 735 ncRNA e 863 prote?nas. Cerca de 94.75% genes preditos tamb?m estavam presentes em anota??o da Leishmania panamensis (MHOM/PA/94/PSC-1). Comparando o n?mero de rna n?o codificante e prote?nas foi evidenciado a presen?a de rela??es entre cromossomos e ncrna. Todos os genes encontrados foram mapeados no genoma da Leishmania braziliensis e armazenados em um modelo de banco de dados relacional constru?do em MySQL e PHP 5.0. Todos os dados resultantes desse trabalho est?o dispon?veis.

Made available in DSpace on 2014-12-17T14:55:26Z (GMT). No. of bitstreams: 1 FranciscoAA_Capa_ate_11.pdf: 7331054 bytes, checksum: 95b093e73afc9c2e5df63a5d0c5b2c6b (MD5) Previous issue date: 2005-07-06 / A 2.5D ray-tracing propagation model is proposed to predict radio loss in indoor environment. Specifically, we opted for the Shooting and Bouncing Rays (SBR) method, together with the Geometrieal Theory of Diffrartion (GTD). Besides the line-of-sight propagation (LOS), we consider that the radio waves may experience reflection, refraction, and diffraction (NLOS). In the Shooting and Bouncing Rays (SBR) method, the transmitter antenna launches a bundle of rays that may or may not reach the receiver. Considering the transmitting antenna as a point, the rays will start to launch from this position and can reach the receiver either directly or after reflections, refractions, diffractions, or even after any combination of the previous effects. To model the environment, a database is built to record geometrical characteristics and information on the constituent materials of the scenario. The database works independently of the simulation program, allowing robustness and flexibility to model other seenarios. Each propagation mechanism is treated separately. In line-of-sight propagation, the main contribution to the received signal comes from the direct ray, while reflected, refracted, and diffracted signal dominate when the line-of-sight is blocked. For this case, the transmitted signal reaches the receiver through more than one path, resulting in a multipath fading. The transmitting channel of a mobile system is simulated by moving either the transmitter or the receiver around the environment. The validity of the method is verified through simulations and measurements. The computed path losses are compared with the measured values at 1.8 GHz ftequency. The results were obtained for the main corridor and room classes adjacent to it. A reasonable agreement is observed. The numerical predictions are also compared with published data at 900 MHz and 2.44 GHz frequencies showing good convergence / Este trabalho apresenta um modelo 2,5D de tra?ado de raios para predi??o de propaga??o em ambientes interiores (indoor). Especificamente, optou-se pelo M?todo dos Raios For?ados (SBR) em combina??o com a Teoria Geom?trica da Difra??o (GTD). Considera-se que, al?m de propaga??o em visada direta (LOS), podem ocorrer os mecanismos de reflex?o, refra??o e difra??o (NLOS). No M?todo dos Raios For?ados (SBR), a antena transmissora lan?a um feixe de raios que pode ou n?o alcan?ar o receptor. Considerando a antena transmissora como elemento pontual, os raios s?o lan?ados dessa posi??o, podendo alcan?ar o receptor diretamente ou mediante reflex?es, refra??es, difra??es, ou pela combina??o dessas modalidades de propaga??o. Para o modelamento do ambiente, um banco de dados ? constru?do para armazenar as caracter?sticas geom?tricas e informa??es dos materiais constituintes do cen?rio. O banco de dados funciona independentemente do programa de simula??o, possibilitando robustez ? implementa??o e maior flexibilidade para a representa??o de outros ambientes. Cada mecanismo de propaga??o ? tratado separadamente. Na propaga??o em linha de visada, o raio direto oferece maior contribui??o ao sinal recebido, enquanto o raio refletido, refratado e difratado apresentam maior influ?ncia quando a propaga??o ocorre com obstru??o. Neste caso, o sinal transmitido alcan?a o receptor por diversas trajet?rias, ocorrendo desvanecimento por m?ltiplos percursos. O canal de transmiss?o, no sistema m?vel, ? simulado deslocando-se o transmissor ou o receptor ao longo do ambiente. A valida??o do m?todo ? verificada atrav?s de simula??es e medi??es. As perdas de percurso calculadas s?o comparadas com os valores medidos, na freq??ncia de 1,8 GHz. Os resultados s?o obtidos para ambientes de corredor e salas de aula adjacentes. Uma boa converg?ncia ? observada. Os resultados num?ricos deste trabalho s?o tamb?m comparados com os dispon?veis na literatura especializada, na freq??ncia de 900 MHz e 2,44 GHz, mostrando boa concord?ncia

Made available in DSpace on 2014-12-17T14:55:48Z (GMT). No. of bitstreams: 1 FredSRP.pdf: 1871145 bytes, checksum: 9d94e1a0030a3d2f8d2aa6aaa2df93bd (MD5) Previous issue date: 2006-02-17 / The development of wireless telecommunication in the last years has been great. It has been taking academics to conceive new ideas and techniques. Their aims are to increase the capacity and the quality of the system s services. Cells that are smaller every time, frequencies that are every time higher and environments that get more and more complex, all those facts deserve more accurate models the propagation prediction techniques are inserted in this context and results with a merger of error that is compatible with the next generations of communication systems. The objective of this Work is to present results of a propagation measurement campaign, aiming at pointing the characteristics of the mobile systems covering in the city of Natal (state of Rio Grande do Norte, Brazil). A mobile laboratory was set up, using the infra-structure available and frequently used by ANATEL. The measures were taken in three different areas: one characterized by high buildings, high relief, presence of trees and towers of different highs. These areas covered the city s central zone, a suburban / rural zone and a section of coast surrounded by sand dunes. It is important to highlight that the analysis was made taking into consideration the actual reality of cellular systems with covering ranges by reduced cells, with the intent of causing greater re-use of frequencies and greater capacity of telephone traffic. The predominance of telephone traffic by cell in the city of Natal occurs within a range inferior to 3 (three) km from the Radio-Base Station. The frequency band used was 800 MHz, corresponding to the control channels of the respective sites, which adopt the FSK modulation technique. This Dissertation starts by presenting a general vision of the models used for predicting propagation. Then, there is a description of the methodology used in the measuring, which were done using the same channels of control of the cellular system. The results obtained were compared with many existing prediction models, and some adaptations were developed by using regression techniques trying to obtain the most optimized solutions. Furthermore, according to regulations from the old Brazilian Holding Telebr?s, a minimum covering of 90% of a determined previously area, in 90% of the time, must be obeyed when implanting cellular systems. For such value to be reached, considerations and studies involving the specific environment that is being covered are important. The objective of this work is contribute to this aspect / O enorme desenvolvimento das comunica??es sem fio tem levado estudiosos a conceber novas id?ias e t?cnicas visando aumentar a capacidade e melhorar a qualidade de servi?o dos sistemas de comunica??o m?vel. C?lulas cada vez menores, freq??ncias cada vez mais altas e ambientes cada vez mais complexos est?o a merecer modelamentos mais acurados e as t?cnicas de predi??o de propaga??o se inserem neste contexto, estando ainda a merecer resultados com margem de erro compat?vel com as pr?ximas gera??es de sistemas de comunica??o. Este trabalho tem por finalidade apresentar os resultados de uma campanha de medidas de propaga??o visando caracterizar a cobertura de sistemas m?veis celulares na cidade do Natal, RN. Um laborat?rio m?vel foi montado aproveitando a estrutura dispon?vel e utilizada rotineiramente pela ANATEL. As medi??es foram efetuadas em ?reas com caracter?sticas de edifica??es, relevo, arboriza??o e alturas de torres diversificadas, abrangendo a zona central da cidade, uma zona de caracter?stica suburbana / rural e trecho litor?neo circundado por dunas. ? importante destacar que a an?lise foi feita considerando a realidade atual dos sistemas celulares com raios de cobertura por c?lula reduzidos visando proporcionar maior reuso de freq??ncias e maior capacidade de tr?fego telef?nico. A predomin?ncia do tr?fego telef?nico por c?lula na cidade do Natal ocorre dentro de um raio inferior a 3 (tr?s) km em rela??o a Esta??o R?dio-Base. A faixa de freq??ncia utilizada foi de 800 MHz, correspondendo aos canais de controle dos respectivos sites, os quais adotam a t?cnica de modula??o FSK. Neste trabalho, apresenta-se inicialmente uma vis?o geral dos modelos utilizados para predi??o de propaga??o. Em seguida, descreve-se a metodologia utilizada nas medi??es, as quais foram efetuadas aproveitando os pr?prios canais de controle do sistema celular. Os resultados obtidos foram comparados com diversos modelos de predi??o existentes e foram desenvolvidas adapta??es utilizando t?cnicas de regress?o na tentativa de obten??o de solu??es mais otimizadas. Al?m disso, ? importante observar que, de acordo com norma da antiga holding brasileira Telebr?s, uma cobertura m?nima de 90% de uma ?rea pr?-estabelecida em 90% do tempo deve ser obedecida em implanta??es de sistemas celulares. Para que tal ?ndice seja obtido, considera??es e estudos envolvendo o ambiente espec?fico de atendimento s?o importantes. Este trabalho apresenta uma contribui??o nesse sentido

Made available in DSpace on 2014-12-17T14:56:12Z (GMT). No. of bitstreams: 1 VictorLCMS_DISSERT.pdf: 2392559 bytes, checksum: f4276b98c00bcaaa7742d7ced860b2b7 (MD5) Previous issue date: 2013-04-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / A serious problem that affects an oil refinery s processing units is the deposition of solid particles or the fouling on the equipments. These residues are naturally present on the oil or are by-products of chemical reactions during its transport. A fouled heat exchanger loses its capacity to adequately heat the oil, needing to be shut down periodically for cleaning. Previous knowledge of the best period to shut down the exchanger may improve the energetic and production efficiency of the plant. In this work we develop a system to predict the fouling on a heat exchanger from the Potiguar Clara Camar?o Refinery, based on data collected in a partnership with Petrobras. Recurrent Neural Networks are used to predict the heat exchanger s flow in future time. This variable is the main indicator of fouling, because its value decreases gradually as the deposits on the tubes reduce their diameter. The prediction could be used to tell when the flow will have decreased under an acceptable value, indicating when the exchanger shutdown for cleaning will be needed / Um s?rio problema que afeta unidades de refino de petr?leo ? a deposi??o e incrusta??o de s?lidos nos equipamentos. Esses res?duos est?o naturalmente presentes no petr?leo ou s?o produtos de rea??es qu?micas durante o seu transporte. Um permutador de calor, quando sujo, perde sua capacidade de aquecer adequadamente o petr?leo, precisando, periodicamente, ser retirado de opera??o, para que possa ser realizada uma limpeza. Informa??es pr?vias do melhor per?odo para realizar as paradas podem melhorar a efici?ncia energ?tica e de produ??o da planta. Esse trabalho desenvolveu um sistema de predi??o da incrusta??o em um permutador da Refinaria Potiguar Clara Camar?o, com base em dados coletados em parceria com a Petrobras. Foram utilizadas redes neurais recorrentes que preveem a vaz?o no permutador em instantes futuros. Essa vari?vel ? o principal indicador da incrusta??o, pois seu valor diminui gradualmente ? medida que os dep?sitos nas paredes dos tubos reduzem seu di?metro. A predi??o pode ser usada para dizer quando a vaz?o ter? ca?do abaixo de um valor satisfat?rio, indicando quando ser? necess?rio retirar o equipamento de opera??o

Made available in DSpace on 2016-04-04T18:31:29Z (GMT). No. of bitstreams: 1 Andre Peternela-2.pdf: 13622452 bytes, checksum: 1f9ac13f6b6653f2fc960f59cfecd1e2 (MD5) Previous issue date: 2009-12-11 / This paper proposes a new Propagation Model that considers lateral diffraction in buildings for signal-level point-multipoint predictions. A review of existing theories of diffraction is presented, as well as topics of analysis of electromagnetic signals propagation and propagation models. In the sequence the assumptions of the proposition of the diffraction and propagation model are discussed in order to justify the proposed model. Finally comparative theoretical and experimental results are presented about this new model. / Este trabalho prop?e um novo Modelo de Propaga??o que considera difra??o lateral em edif?cios para predi??es de n?vel de sinal ponto-multiponto. S?o apresentadas as teorias de difra??o existentes, assim como t?picos de an?lise da propaga??o de sinais eletromagn?ticos e modelos de propaga??o. Com as bases te?ricas s?o discutidas as premissas da proposi??o do modelo de difra??o e propaga??o que justificam o modelo proposto neste trabalho. Por fim s?o apresentados resultados te?ricos comparativos e experimentais deste novo modelo.

Made available in DSpace on 2015-03-03T15:28:31Z (GMT). No. of bitstreams: 1 JoaoBC_DISSERT_partes_autorizadas.pdf: 252147 bytes, checksum: e830f27faffa86c9087da28e43e699fd (MD5) Previous issue date: 2010-05-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / We considered prediction techniques based on models of accelerated failure time with random e ects for correlated survival data. Besides the bayesian approach through empirical Bayes estimator, we also discussed about the use of a classical predictor, the Empirical Best Linear Unbiased Predictor (EBLUP). In order to illustrate the use of these predictors, we considered applications on a real data set coming from the oil industry. More speci - cally, the data set involves the mean time between failure of petroleum-well equipments of the Bacia Potiguar. The goal of this study is to predict the risk/probability of failure in order to help a preventive maintenance program. The results show that both methods are suitable to predict future failures, providing good decisions in relation to employment and economy of resources for preventive maintenance. / Consideramos t?cnicas de predi??o baseadas em modelos de tempo de falha acelerado com efeito aleat?rio para dados de sobreviv?ncia correlacionados. Al?m do enfoque bayesiano atrav?s do Estimador de Bayes Emp?rico, tamb?m discutimos sobre o uso de um m?todo cl?ssico, o Melhor Preditor Linear N?o Viciado Emp?rico (EBLUP), nessa classe de modelos. Para ilustrar a utilidade desses m?todos, fazemos aplica??es a um conjunto de dados reais envolvendo tempos entre falhas de equipamentos de po?os de petr?leo da Bacia Potiguar. Neste contexto, o objetivo ? predizer os riscos/probabilidades de falha com a finalidade de subsidiar programas de manuten??o preventiva. Os resultados obtidos mostram que ambos os m?todos s?o adequados para prever falhas futuras, proporcionando boas decis?es em rela??o ao emprego e economia de recursos para manuten??o preventiva

Made available in DSpace on 2014-12-17T14:55:23Z (GMT). No. of bitstreams: 1 RonaldoAM.pdf: 2082162 bytes, checksum: 2dd11d30b856b23cf429317a1e68bfbe (MD5) Previous issue date: 2006-06-12 / In this dissertation new models of propagation path loss predictions are proposed by from techniques of optimization recent and measures of power levels for the urban and suburban areas of Natal, city of Brazilian northeast. These new proposed models are: (i) a statistical model that was implemented based in the addition of second-order statistics for the power and the altimetry of the relief in model of linear losses; (ii) a artificial neural networks model used the training of the algorithm backpropagation, in order to get the equation of propagation losses; (iii) a model based on the technique of the random walker, that considers the random of the absorption and the chaos of the environment and than its unknown parameters for the equation of propagation losses are determined through of a neural network. The digitalization of the relief for the urban and suburban areas of Natal were carried through of the development of specific computational programs and had been used available maps in the Statistics and Geography Brazilian Institute. The validations of the proposed propagation models had been carried through comparisons with measures and propagation classic models, and numerical good agreements were observed. These new considered models could be applied to any urban and suburban scenes with characteristic similar architectural to the city of Natal / Nesta tese novos modelos de predi??o de perda de percurso de propaga??o s?o propostos a partir de t?cnicas de otimiza??es recentes e de medi??es de n?veis de pot?ncias obtidas para as ?reas urbana e suburbana de Natal, cidade do Nordeste Brasileiro. Estes novos modelos s?o: (i) um modelo estat?stico que foi implementado baseado na adi??o de estat?sticas de 2a. ordem para a pot?ncia e a altimetria do relevo ao modelo de perdas lineares; (ii) um modelo com redes neurais artificiais que usou o treinamento do algoritmo backpropagation, a fim de obter a equa??o de perdas de propaga??o; (iii) um modelo baseado na t?cnica dos trajetos aleat?rios, que considera a aleatoriedade da absor??o e do caos do meio ambiente e que seus par?metros desconhecidos para a equa??o de perdas de propaga??o s?o determinados atrav?s de uma rede neural. A digitaliza??o do relevo das ?reas urbanas e suburbanas de Natal foi realizada atrav?s do desenvolvimento de programas computacionais espec?ficos e foram usados os mapas existentes no Instituto Brasileiro de Geografia e Estat?stica. As valida??es dos modelos propostos de predi??o de perda de propaga??o foram realizadas atrav?s de compara??es com medidas e modelos cl?ssicos de propaga??o, obtendo-se boas concord?ncias num?ricas. Estes novos modelos poder?o ser aplicados a qualquer cen?rio urbano e suburbano com caracter?sticas arquitet?nicas semelhantes ? cidade de Natal