Made available in DSpace on 2014-06-12T15:57:06Z (GMT). No. of bitstreams: 2 arquivo3140_1.pdf: 4172532 bytes, checksum: b7cc6b23a678d29aa1a5c9c9da0617e9 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Com o objetivo de produzir produtos individualizados, muitas vezes, as empresas se deparam com a necessidade de altos investimentos, elevando assim os preços de produtos individualizados. A partir dessa necessidade, muitas empresas, começaram a introduzir o conceito de plataforma comum, com o objetivo de desenvolver uma grande variedade de produtos, reusando suas partes comuns. No contexto de linha de produto de software, essa plataforma em comum é chamada de arquitetura de referência, que prove uma estrutura comum de alto nível onde os produtos são construídos. A arquitetura de software, de acordo com alguns pesquisadores, está se tornando o ponto central no desenvolvimento de linha de produtos, sendo o primeiro modelo e base para guiar a implementação dos produtos. No entanto, essa arquitetura sofre modificações com o passar do tempo, com o objetivo de satisfazer as necessidades dos clientes, a mudanças no ambiente, além de melhorias e mudanças corretivas. Desta forma, visando assegurar que essas modificações estão em conformidade com as especificações da arquitetura, não introduziram novos erros e que as novas funcionalidades continuam funcionando como esperado, a realização de testes de regressão é importante. Neste contexto, este trabalho apresenta uma abordagem de regressão utilizada tanto para reduzir o número de testes que precisam ser reexecutados, da arquitetura de referência e da arquitetura dos produtos, quanto para tentar assegurar que novos erros não foram inseridos, depois que essas arquiteturas passaram por uma evolução ou mudança corretiva. Como regressão é vista como uma técnica que pode ser aplicada em mais de uma fase de teste, neste trabalho regressão é aplicado durante a fase de integração, uma vez que, ao final desta fase teremos as arquiteturas da linha de produto testadas. Desta forma, uma abordagem de integração também foi proposta. Esta dissertação também apresenta uma validação inicial da abordagem, através de um estudo experimental, mostrando indícios de que será viável a aplicação de testes de regressão nas arquiteturas de uma linha de produto de software

Orientador: José Pissolato Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-17T05:27:30Z (GMT). No. of bitstreams: 1 Castilho_RenatoMaioli_M.pdf: 2356762 bytes, checksum: ada04c502811c2989682af0e17b5a512 (MD5) Previous issue date: 2010 / Resumo: Este trabalho apresenta um método de análise do carregamento de linhas de transmissão aérea em tempo real o qual relaciona o respectivo carregamento da linha de transmissão com fatores externos que, direta ou indiretamente, exercem influência sobre os limites de operação da linha. Através da implementação de um sistema de monitoramento em uma linha de 230 kV da Eletronorte, informações atmosféricas e da própria linha foram coletadas e transmitidas via cabo OPGW para um centro de controle onde, a partir de um software, obteve-se a ampacidade da linha em tempo real. Fazendo uso do banco de dados gerado com as informações coletadas pelo sistema de monitoramento e utilizando técnicas de redes neurais artificiais, foi desenvolvido um módulo preditor da temperatura superficial do cabo, possibilitando estimar a ampacidade da linha no curto prazo. A pesquisa se deu em três fases, na primeira foi feito o desenvolvimento dos equipamentos que compõem o sistema de monitoramento, na segunda fase foi feita a implementação do sistema na linha de 230 kV e na terceira fase foi dado o tratamento matemático às informações coletadas. A abordagem realizada dos dados obtidos pelo sistema de monitoramento proposto gerou resultados interessantes no que tange a busca pelo melhor aproveitamento da linha e mostrou ser um sistema bastante útil para a operação no despacho de carga. O sistema de monitoramento analisado neste trabalho de pesquisa, foi desenvolvido pelo Centro de Pesquisa e Desenvolvimento em Telecomunicações - CPqD em parceria com a Universidade Federal do Pará - UFPA e faz parte do programa de pesquisa e desenvolvimento das Centrais Elétricas do Norte do Brasil S.A. - Eletronorte. / Abstract: This paper presents a method of transmission line load analysis in real time, which relates of the transmission line loading with external factors that directly or indirectly exert influence over the operating range of the line. By setting up a monitoring system in a line of 230 kV, weather and line parameters information were collected and transmitted via OPGW cable to a control center where, using dedicated software, we obtained the ampacity of the line in real time. Making use of the database generated with information collected by the monitoring system and using techniques of artificial neural networks, we developed a predictor module surface temperature of the cable, allowing use to estimate the ampacity of the line in the short term. The research was divided in three phases, at first was developed the equipment that make up the monitoring system in the second round was implemented the monitoring system at 230 kV line and in the third stage was given the mathematical treatment of collected information. The data obtained by the proposed monitoring system, has generated interesting results allowing an optimized use of the line the system proved to be very useful for the line loading operation. The monitoring system of loading examined in this research work was developed by the Center for Research and Development in Telecommunications - CPqD in partnership with the Federal University of Pará - UFPA and is part of Centrais Elétricas do Norte do Brasil S.A - Eletronorte research and development program. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: Maria Cristina Dias Tavares / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-13T12:17:57Z (GMT). No. of bitstreams: 1 Montanari_AllanAlves_M.pdf: 7585929 bytes, checksum: 4c00ba94f40e488cc4da50c4089e8630 (MD5) Previous issue date: 2009 / Resumo: Este trabalho apresenta um esquema de religamento monopolar adaptativo rápido para otimizar o tempo compreendido entre a abertura e o religamento da fase sob falta. A proteção adaptativa recompõe rapidamente o sistema de transmissão de energia elétrica, minimizando a probabilidade de propagação de perturbações severas no sistema. O método é fundamentado na análise de dados de ensaios de arco secundário gerados e monitorados numa estrutura de testes construída em campo, composta por um trecho real de linha de transmissão (três torres e dois vãos). Analisou-se o conteúdo harmônico da tensão e da corrente de arco secundário através da aplicação da Transformada de Fourier Janelada. Tais análises viabilizaram a realização de um tratamento estatístico para a caracterização da assinatura harmônica de arco secundário. Simulações de faltas monofásicas foram realizadas utilizando dados provenientes dos Ensaios de arco secundário. Desenvolveu-se um algoritmo baseado nas características Harmônicas da tensão da fase sob falta, calculadas através do deslocamento de uma janela de tempo sobre os sinais analisados (Transformada de Fourier Janelada). O algoritmo determina a existência do arco secundário e fornece informações a respeito do instante no qual o religamento pode ser realizado com sucesso. O método apresenta também um mecanismo para a detecção da característica permanente ou transitória da falta. / Abstract: This work presents a fast adaptive single-phase autorec1osingseheme to optimize the period between the tripping operation and the rec10sure of the faulted phase breakers. The adaptive proteetion quiekly reeomposes the eleetric power transmission, minimizing the probability of severe damages propagation in the system. The method is based on the analysis of secondary are field tests data that were generated and monitored in an infra-structure which consists of a real transmission line section (three towers and two spans). The harmonic content of the secondary are voltage and eurrent was analyzed by the application of Short Time Discrete Fourier Transform. Such analysis made it possible to implement a statistical approach in order to obtain the secondary are harmonic signature. Single-phase faults computer simulations were performed using the data obtained from the secondary are tests. It was developed an algorithm based on the voltage harmonic content of the faulted phase, which was ea1culated by shifting a window on the analyzed signals (Short Time Discrete Fourier Transform). The algorithm determines the secondary are existence and provides information in order to suceessfully rec10se the circuit breaker. The method also presents a control mechanism responsible for identifying whether the fault is a permanent one or a transient fault. / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

A engenharia de software tem buscado, nas últimas décadas, assemelhar-se a outras disciplinas de engenharia, introduzindo métodos, técnicas e ferramentas que possibilitem a melhoria da produtividade e qualidade no desenvolvimento de software em ordem de grandeza similar à alcançada pela indústria de manufatura. Uma das abordagens mais bem sucedidas neste sentido tem sido o emprego das práticas de reuso sistematizado de software, como o desenvolvimento baseado em componentes e, em especial, as linhas de produtos de software ou engenharia de família de produtos. No Brasil, um dos segmentos que mais produz e consome software é o setor financeiro, uma vez que todos os seus produtos e serviços são entregues através da tecnologia da informação. Por este motivo, torna-se fundamental a compreensão de como acontecem os processos de reuso de software neste segmento e como estes contribuem para o sucesso dos projetos. Esta pesquisa apresenta o mapeamento do cenário de reuso de software no setor financeiro no Brasil, baseado em estudos de caso conduzidos em cinco, dos dez maiores bancos instalados no país. / During last decades, Software Engineering has been aiming at be more disciplined as other engineering disciplines, by introducing methods, techniques and tools that provide productivity and quality improvement in the same levels reached by manufacturing industries. One of the most successful approaches towards this goal has been the use of systematic software reuse practices, such as component based development and, specially, software product lines or product family engineering. In Brazil, one of the most active sectors in consuming and producing software products is the financial sector, once all of its products and services are delivered through Information Technology. This is the reason why is so important to understand how software reuse processes occurs in this sector and how do they contribute to projects success. This research presents scenario of software reuse in the financial sector in Brazil, based on case research conducted in five of the ten largest banks installed in the country.

M.Ing. (Electrical And Electronic Engineering) / In-vehicle Power Line Communication (PLC) is an emerging technology that can easily bene t the automotive industry by reducing the amount of wires (and hence cost, weight and complexity) for vehicle wire harnesses. The reduction in weight would also lead to less fuel consumption. This dissertation aims at taking the research of this technology a step towards fully understanding the vehicle's power line as a communication medium. We investigate the bit error characteristics of a readily available transceiver on the vehicle's power bus. To do so, we develop and perform bit error recording over the medium to get experimental results with the battery line under di ferent operating conditions. Using the rst set of these results, we parametrise di erent kinds of Markov models to see which one simulates the channel best. Using the preferred model, we then model the rest of the sets of results so that we can simulate the channel's bit error characteristics under these di erent conditions. Using these models, we demonstrate how these simulations can be used to evaluate the performance of di erent error detection and correction techniques. In particular, we evaluate the error detection mechanisms used in the popular in-vehicle Local Intercon- nect Network (LIN) protocol, in addition to some simple error correction techniques.

D.Ing. / In this study we consider the application of Reed-Solomon codes on two distinct channels. The first channel is the packet erasure channel, where packets are either received errorfree,or packets are lost. The second channel is the power line channel where additive Gaussian noise,, impulsive noise and narrowband noise are encountered In this thesis we focus on M-FSK modulation for the power line channel. For the packet erasure channel,we develop two new erasures-only decoders .The distinction between the two decoders is that the one is optimized for burst erasure correction, while the second decoder is optimized for random erasure correction.It is found that for single burst erasures, or bursterasures contained within n - k elements (where n is the code length and k is the number of information elements to be encoded), the best performance is obtained with the burst erasure decoder. When used in conjunction with a modified interleaver found in the literature, the developed random erasure decoder yields the best all-round performance. The main contribution to the power line channel is the development of a combined demodulation and decoding strategy to detect narrowband interference When standard Reed-Solomon codes operate in a channel where narrowband interference is present, undetected errors result. With the proposed decoding strategy it is found that wideband noise (a generalization of impulsive noise) affects the performance more negatively than narrowband noise for M-FSK modulation. .

The architecture of a software system is defined by significant decisions that drive the way in which the software is designed implemented and maintained. In the context of software product lines, these decisions will determine the design of an architec- ture that provides the software with the ability to be configured for different product variants and extended to accommodate future requirements. Although, variability models describe the different configurations of current and fu- ture products that the product line supports, the knowledge of how the architecture was designed to support variations of a product in space and time exists only in the architects’ mind or remains implicit in architectural models. This thesis argues that the knowledge found in architectural models and design rationale can be used to facilitate the derivation of product variants and the evolution of the product line. To support this notion, we propose the AKinSPL method for capturing the architec- tural knowledge in software product lines. The method is founded on the factors that architects take into consideration when designing the architecture, and a meta-model that represents the mental models and processes architects follow during the creation of a product line architecture. To validate the concepts of AKinSPL, its guidelines were mapped to activities of the PuLSE-DSSA methodology and new artifacts were created to capture architectural knowledge on the basis of those guidelines. Next, it was applied to capture the archi- tectural knowledge of an embedded software system for automatic control of agricul- tural equipment. The results showed that diagrams augmented with design rationale enable a faster understanding of the purpose of the architectural models. Similarly, the prescriptions of the architecture with respect to the implementation are conveyed more easily. / jmercadoh@gmail.com Tel: +4916099058545

Previous studies have shown that the incidence rate of intervening strong Mg II absorbers towards gamma-ray bursts (GRBs) were a factor of 2-4 higher than towards quasars. Exploring the similar sized and uniformly selected legacy data sets XQ-100 and XSGRB, each consisting of 100 quasar and 81 GRB afterglow spectra obtained with a single instrument (VLT/X-shooter), we demonstrate that there is no disagreement in the number density of strong Mg II absorbers with rest-frame equivalent widths W-r(lambda 2796) > 1 angstrom towards GRBs and quasars in the redshift range 0.1 less than or similar to z less than or similar to 5. With large and similar sample sizes, and path length coverages of Delta z = 57.8 and 254 : 4 for GRBs and quasars, respectively, the incidences of intervening absorbers are consistent within 1 sigma uncertainty levels at all redshifts. For absorbers at z < 2.3, the incidence towards GRBs is a factor of 1.5 +/- 0.4 higher than the expected number of strong Mg II absorbers in Sloan Digital Sky Survey (SDSS) quasar spectra, while for quasar absorbers observed with X-shooter we find an excess factor of 1.4 +/- 0.2 relative to SDSS quasars. Conversely, the incidence rates agree at all redshifts with reported high-spectral-resolution quasar data, and no excess is found. The only remaining discrepancy in incidences is between SDSS Mg II catalogues and high-spectral-resolution studies. The rest-frame equivalent-width distribution also agrees to within 1 sigma uncertainty levels between the GRB and quasar samples. Intervening strong Mg II absorbers towards GRBs are therefore neither unusually frequent, nor unusually strong.

Software reuse is perceived as the key to successful software development because of the potential for shortened time to market, increased quality and reduced costs. In recent years software product lines have emerged as a promising way to achieve large scale software reuse. Challenges against successful reuse when developing in a software product line involves management of the differences between products, and the differences between different releases of the products. In this thesis we present the experiences from a series of case studies within four software companies. Based on these we present a taxonomy of the technical solutions to manage product differences, a historical essay of how components in a software product line can evolve and what mechanisms that are used to support this evolution. From this we elaborate on the connection between evolution and variability, i.e. the ability of the software architecture and components to support the differences between products. We argue that evolution is strongly connected to variability, and that by foreseeing the evolution, the software can be instrumented with appropriate variability mechanisms accordingly. Moreover, we argue that some types of evolution are more frequent than others, and that the efforts should mainly go in the direction of foreseeing and instrumenting for these types of evolution.

We present the results of an optical spectroscopic survey of 46 heavily obscured quasar candidates. Objects are selected using their mid-infrared (mid-IR) colours and magnitudes from the Wide-Field Infrared Survey Explorer (WISE) anzd their optical magnitudes from the Sloan Digital Sky Survey. Candidate Active Galactic Nuclei (AGNs) are selected to have mid-IR colours indicative of quasar activity and lie in a region of mid-IR colour space outside previously published X-ray based selection regions. We obtain optical spectra for our sample using the Robert Stobie Spectrograph on the Southern African Large Telescope. 30 objects (65 per cent) have identifiable emission lines, allowing for the determination of spectroscopic redshifts. Other than one object at z similar to 2.6, candidates have moderate redshifts ranging from z = 0.1 to 0.8 with a median of 0.3. 21 (70 per cent) of our objects with identified redshift (46 per cent of the whole sample) are identified as AGNs through common optical diagnostics. We model the spectral energy distributions of our sample and found that all require a strong AGN component, with an average intrinsic AGN fraction at 8 mu m of 0.91. Additionally, the fits require large extinction coefficients with an average E(B - V)(AGN) = 17.8 (average A(V)(AGN) = 53.4). By focusing on the area outside traditional mid-IR photometric cuts, we are able to capture and characterize a population of deeply buried quasars that were previously unattainable through X-ray surveys alone.