Esta pesquisa tem como objetivo apresentar um método para a coordenação dos Relés Direcionais de Sobrecorrente (RDS) associados ao sistema de proteção de um Sistema Elétrico de Potência (SEP) malhado. O SEP malhado, referente a uma parte do sistema de subtransmissão da rede básica brasileira, em concessão da Companhia de Transmissão de Energia Elétrica Paulista (CTEEP), foi simulado via o software CAPE (Computer-Aided Protection Engineering) a partir da base de dados, para estudos de curtos-circuitos, disponibilizada pelo Operador Nacional do Sistema (ONS). Dada a topologia e a operação do SEP malhado em análise, um método de otimização híbrido foi implementado baseado na combinação e aplicação de Programação Linear (PL) e Algoritmo Genético (AG). O algoritmo desenvolvido permitiu a realização de diversos estudos de curtos-circuitos necessários para a obtenção e avaliação da coordenação dos pares de RDS, tanto para a topologia principal do SEP em análise, como para outras configurações de operação caracterizadas, principalmente, pela alteração topológica do SEP. Os resultados demonstram que o algoritmo foi capaz de fornecer uma coordenação adequada para os RDS, respeitando todas as restrições impostas pelo problema de coordenação. / The aim of this work is to present a method for directional overcurrent relays coordination in a meshed power system which is part of the Brazilian power transmission system operated by São Paulo State Electric Power Transmission Company (CTEEP - Companhia de Transmissão de Energia Elétrica Paulista). This power system was simulated by CAPE (Computer-Aided Protection Engineering) software using the database of short circuits studies which is provided by the Electric System National Operator (ONS - Operador Nacional do Sistema). Given a specific power system topology and its operating conditions, the hybrid algorithm was developed based on the combination and execution of linear programming and genetic algorithm. Several short circuits scenarios were evaluated in order to obtain and assess the coordination between the pairs of directional overcurrent relays. In such scenarios, it was considered the main network topology, as well as other network operating conditions, mainly caused by certain topological variations. The results show that the hybrid algorithm provided a feasible coordination solution for the considered directional overcurrent relays.

Um sistema elétrico de potência agrega toda a estrutura pela qual a energia elétrica percorre, desde a sua geração até o seu consumo final. Nas últimas décadas observou-se um significativo aumento da demanda e, consequentemente, um aumento das interligações entre sistemas, tornando assim a operação e o controle destes extremamente complexos. Com o fim de obter a desejada operação destes sistemas, inúmeros estudos na área de Proteção de Sistemas Elétricos são realizados, pois é sabido que a interrupção desses serviços causam transtornos que podem assumir proporções desastrosas. Em sistemas elétricos malhados, nos quais as correntes de curto-circuito podem ser bidirecionais e podem ter intensidades diferentes devido a alterações topológicas nos mesmos, coordenar relés de sobrecorrente pode ser uma tarefa muito trabalhosa caso não haja nenhuma ferramenta de apoio. Neste contexto, este trabalho visa o desenvolvimento de uma metodologia eficiente que determine os ajustes otimizados dos relés de sobrecorrente direcionais instalados em sistemas elétricos malhados de forma a garantir a rapidez na eliminação da falta, bem como a coordenação e seletividade, considerando as várias intensidades das correntes de curto-circuito. Seguindo essa linha de raciocínio, observou-se que o uso de técnicas metaheurísticas para lidar com o problema da coordenação de relés é capaz de alcançar resultados significativos. No presente projeto, dentre os algoritmos inteligentes estudados, optou-se por pesquisar a aplicação do Algoritmo Enxame de Partículas Evolutivo (Evolutionary Particle Swarm Optimization) por este apresentar como características as vantagens tanto do Algoritmo Enxame de Partículas (Particle Swarm Optimization) quanto as dos Algoritmos Genéticos, possuindo assim grande potencial para solução destes tipos de problemas. / An electric power system aggregates all the structure in which the electric energy travels, from its generation to the final user. In the last decades it has been observed a significative increase of the demand and, consequently, an increment of the number of interconnections between systems, making the operation and control of them extremely complex. Aiming to obtain a good operation of this kind of systems, a lot of effort in the research area of power system protection has been spent, because it is known that the interruption of this service causes disorders that may assume disastrous proportions. In meshed power systems, in which the shortcircuit currents might be bidirectional and might have different magnitudes due to topological changes on them, to coordinate overcurrent relays may be a really hard task if you do not have a support tool. Look in this context, this work aims the development of and efficient methodology thats determine the optimal parameters of the directional overcurrent relays in a meshed electric power system ensuring the quickness in the fault elimination, as well as the coordination and selectivity of the protection system, considering the various intensities of the short-circuit currents. Maintaining this line, it has been noticed that the use of metaheuristics to deal with the problem of relay coordination is capable of achieving promissory results. In the present research, among the studied intelligent algorithms, it was chosen to use in it the Evolutionary Particle Swarm Optimization, due to its features thats is the advantages of the Particle Swarm Optimization as well as the Genetic Algorithms ones, hence it has great potential do solve theses kind of problems.

Propriedades ópticas, magnéticas e elásticas de duas liomesofases nemáticas tipo I (decilsulfato de sódio/água/ n-decanol e laurato de potássio/água/cloreto de potássio) e urna tipo II (decilsulfato de sódio/água/n-decanol /sulfato de sódio) são estudadas. Nas investigações de tais propriedades as medidas realizadas e instrumentação/meios utilizados foram os seguintes: medidas de sinais ópticos, texturas e temperaturas de transições de fases foram obtidas com auxilio de um microscópio petrográfico com temperatura controlada na platina; medidas de índices de refração e birrefringências obtiveram- se com adaptações do refratômetro de Pulfrich; medidas de susceptibilidades diamagnéticas direcionais foram realizadas com adaptações ao magnetômetro de amostra vibrante; medidas de constantes elásticas foram obtidas com auxilio de uma montagem especial. São realizados cálculos para as susceptibilidades diamagnéticas direcionais e respectivas anisotropias moleculares para alcanos, álcoois e anfifilicos de interesse em liornesofases . Da comparação entre as anisotropias moleculares calculadas e as medidas em liomesofases correspondentes, infere-se que o ordenamento molecular de anfifilicos, nas mesofases, deve ser alto. O método de Kirkwood, que permite correlacionar polarizabilidade elétrica com a susceptibilidade diamagnética molecular média em substâncias puras, é estendido e adaptado a misturas complexas, criando assim urna promissora perspectiva de correlação entre as medidas ópticas e magnéticas em liomesofases. Evidências experimentais diretas, da aplicabilidade da teoria do continuo para termo trópicos às liomesofases, são apresentadas. / The optical, magnetic and elastic properties of three nematic lyomesophases are studied. Two are type I (Na decyl sulfate/ water/n- decanol and K laurate/water/K chloride) and one type II (Na decyl sulfate/water/n- decano l/Na sulfate). To measure these properties we used the following equipment : texture and optical sign were observed by optical microscopy with temperature controlled, hot and cold, stages; refractive indices were measured in an adapted Pulfrich refratometer; the individual elements of the diamagnetic susceptibility tensor were measured with a vibrating sample magnetometer; the elastic constants were measured using the Frederikzs transition in a special experimental set-up. Starting from the concept of localized magnetic susceptibilities, molecular anisotropies were calculated for saturated hydrocarbons , alcohols and amphiphilic compounds, which are of interest for lyomesophases. Comparing these results with the experimentally measured anisotropies of the lyomesophases it is possible to conclude that a high degree of molecular order is present in the nematic amphiphilic systems. The Kirkwood method is extended and adapted for complex mixtures. The use of this method opens new perspectives for exploring the correlation between the molecular polarizability and the mean diamagnetic susceptibility.

Les travaux de la thèse se focalisent sur la protection des réseaux de distribution HTA en présence des générateurs distribués (éoliennes, fermes solaires,...). Dans un premier temps, un état de l’art a été réalisé sur les comportements des générateurs en creux de tension, leurs impacts sur le système de protection et les pistes de solution proposées pour y remédier. L’étape suivante est la mise au point d’algorithmes directionnels de détection de défauts, sans mesure de tension. Ces algorithmes s’appuient sur la décomposition en composantes symétriques des courants mesurés. Ces relais doivent empêcher le déclenchement intempestif de protections de surintensité dû au courant de défaut provenant des générateurs distribués. Ils sont moins coûteux par rapport à ceux traditionnels car les capteurs de tension, qui sont indispensables pour ces derniers, peuvent être enlevés. Après détection d’un défaut sur critère de seuil simple (max de I ou max de I résiduel), la direction est évaluée à l’aide d’un algorithme en delta basé sur les rapports courants inverse-homopolaire ou inverse-direct, selon le type de défaut (monophasé ou biphasé). En se basant sur ces rapports, un classifieur SVM (Support Vector Machines), entrainé préalablement à partir des simulations, donne ensuite l’estimation de la direction du défaut (amont ou aval par rapport au relais). La bonne performance de ces algorithmes a été montrée dans la thèse pour différents paramètres du réseau et en présence de différents types de générateurs. Le développement de tels algorithmes favorise la mise en œuvre des protections en réseau, qui pourraient être installées dans les futurs Smart Grids. / This research focuses on the protection of MV distribution networks with Distributed Generators (DGs), such as wind farms or photovoltaic farms, etc. First, the state of art is carried out on fault behaviour of DGs, their impacts on protection system and the mitigation solutions. Next, algorithms are developed for directional relays without voltage sensors. Based on the symmetrical component method, these algorithms help the overcurrent protections to avoid the false tripping issue due to fault contribution of DGs. With the suppression of voltage sensors, such directional relays become cheaper in comparison with the traditional ones. Following the fault detection (the phase or residual current reaches the pick-up value) and depending on fault type (line-to-ground or line-to-line fault), the ratios between the variation (before and during fault) of negative-zero sequence or negative-positive sequence currents are calculated. From these ratios, a SVM (Support Vector Machines) classifier estimates the fault direction (upstream or downstream the detector). The classifier is trained beforehand from transient simulations. This survey shows good performances of the directional algorithms with different network parameters and different kinds of DGs. Such algorithms could be implemented in protections along the feeders in the future smart grids.

No description available.

No description available.

本文欲利用方向距離函數 (DDF) 來驗證中東歐國家銀行業之效率。不同的國家之銀行業者會由於不同的文化、資源稟賦和環境而採取不同的經營模式。因此，本文藉由共同邊界方向距離函數，其允許我們在跨國間不同的技術下，得以估計出銀行的技術效率並加以比較。使用方向距離函數，得以讓我們的模型中納入非意欲產出，此外，其亦允許銀行廠商同時增加產出與縮減投入和非意欲產出，相較於傳統模型，方向距離函數屬於較有彈性之模型。重要的是，不良貸款被視為是貸款過程中之副產品，其可能會降低銀行的利潤和績效。因此，為了減少不良貸款之產生，銀行管理者必須花費額外的成本，以確保借貸者是否有良好的信用，此舉亦可能影響銀行的績效。 本文試圖發展新的共同邊界隨機方向距離函數，其不同於Battese et al. (2004) 所提出的方法，該方法是屬於線性規畫法。此數理規畫法是屬於確定邊界，其無法針對有興趣之參數估計出該標準誤，因此，無法做有效地統計推論。因為本文提出的新共同邊界方向距離函數是隨機的，所以參數之標準誤可以被估計，其亦允許我們建造信賴區間和假設檢定。此外，共同邊界方向距離函數之無效率項可以被進一步設定成環境變數之函數，即Battese and Coelli (1995)所提出之模型。 / This study plans to employ directional technology distance function (DDF) to examine bank efficiency of Central-East European countries. Banks from different countries choose to operate under distinct technologies due to their differences in culture, endowments, and environments. A metafrontier directional distance function will be established, which allows for calculating comparable technical efficiencies for banks under different technologies relative to the potential technology available to the industry across nations. The salient feature of the DDF is its ability to include undesirable outputs into the model. In addition, it allows for a bank to simultaneously expand outputs and contract inputs, as well as undesirable outputs. It is important to note that the non-performing loans (NPL) can be regarded as a by-product of various loans granted, which lowers a bank’s profitability and performance. To reduce the occurrence of NPL bank managers have to spend extra costs to confirm whether the potential applicants for loans have good credit before granting loans to them. This may also affect the bank’s performance. This study attempts to develop a new metafrontier DDF in the context of the stochastic frontier approach, which differs from the one proposed by Battese et al. (2004) who suggest the use of a linear and/or a quadratic programming technique. The mathematical programming technique is known as deterministic, which is unable to estimate the standard errors for the parameters of interest. Hence, no statistical inference can be made. As our new metafrontier DDF is stochastic, the standard errors of the parameters are estimable, which permits establishing confidence intervals and hypotheses testing for the parameters. Moreover, the inefficiency term of the metafrontier DDF can be further specified as a function of several environmental variables of the form proposed by Battese and Coelli (1995).

Dans cette thèse, nous explorons premièrement la notion de directionnalité lors de la conception de repères d'ondelettes du plan. Cette propriété, qui semble essentielle pour la vision biologique, donne lieu à une meilleure représentation des contours d'objets dans les décompositions d'images utilisant ces repères. Elle génère en outre une redondance supplémentaire qui exploitée à bon escient, permet par exemple de réduire les effets d'un bruit additif (gaussien). Nous montrons également comment cette directionnalité, généralement perçue comme un paramètre figé, peut être adaptée localement aux éléments d'une image. Nous définissons ainsi le concept d'analyse d'images multisélective. Dans ce cadre, des règles de récurrence héritées d'une analyse multirésolution circulaire associent des ondelettes d'une certaine sélectivité angulaire pour générer des ondelettes de plus faible directionnalité jusqu'à l'obtention d'une ondelette totalement isotrope. Dans le cas d'un repère d'ondelettes linéaire, ces différents niveaux de sélectivité ont la possibilité de s'ajuster localement au contenu d'une image. Nous constatons par ailleurs que cette adaptabilité fournit de meilleures reconstructions que les méthodes à sélectivité fixe lors d'approximations non linéaires d'images. Cette thèse traite ensuite du problème de l'analyse de données représentées sur la sphère. Il a été établi précédemment [AV99] que la transformée continue en ondelettes (CWT) s'étend à cet espace par l'emploi d'une dilatation stéréographique respectant la compacité de S2. Dans certain cas, il est utile de réduire la redondance de cette transformée, ne fut ce que pour faciliter le traitement des données dans l'espace multi-échelle généré. Nous étudions par conséquent comment créer des repères sphériques semi-continus, où seule l'échelle est échantillonnée, et totalement discrétisés. Nous tirons parti dans ce dernier cas de grilles sphériques équi-angulaires et des règles de quadrature associées pour obtenir des conditions suffisantes à la reconstruction des fonctions analysées. Les capacités d'analyse et de synthèse de repères d'ondelettes DOG sont également testées sur des exemples de données sphériques. Une dernière partie de ce document est dédiée à l'étude d'un objet physique étonnant : la couronne solaire. Cette couche extérieure du soleil est observée depuis 1996 par l'expérience EIT à bord du satellite SoHO dans différentes longueurs d'onde de l'ultraviolet lointain. La compréhension physique des multiples phénomènes apparaissant dans la couronne solaire passe par le traitement automatique des images EIT. Dans cette tâche, nous nous limitons à deux problèmes particuliers. Nous utilisons premièrement la CWT et sa capacité à analyser la régularité locale d'une image pour gommer les traces laissées par les rayons cosmiques, majoritairement non solaires, sur les enregistrements EIT. Deuxièmement, la couronne solaire contient des éléments de faible taille (<60arcsec) nommés points brillants (ou BPs pur Bright points). Ceux-ci trouvent leur origine dans l'échauffement local du plasma coronal sous l'action du champs magnétique solaire. En abordant une approche similaire à celle développée en [Bij99], nous étudions comment sélectionner et caractériser ces BPS en décomposant une image en ses objets constitutifs. Ces derniers sont issus de tubes de maxima dans la description multi-échelle de l'image, c'est-à-dire d'une généralisation discrète des lignes de maxima de la CWT.

Deregulation of the airlines in the United States spawned a free-for-all system which led to a variety of agents within the aviation system all seeking to optimize their own piece of the aviation system, and the net result was that the aviation system itself was not optimized in aggregate, frequently resulting in delays. Research on the efficiency of the system has likewise focused on the individual agents, primarily focusing on the municipalities in an economic context, and largely ignoring the consumer. This paper develops the case for a systemic efficiency measurement which incorporates the interests of the airlines and the consumers with those of the airport operating municipalities in three different Data Envelopment Analysis (DEA) models: traditional Charnes-Cooper-Rhodes and Banker-Charnes-Cooper models, and a Directional Output Distance Function model, devised and interpreted using quality management principles. These models were combined to allow the resulting efficiencies of the operating configurations of the given airport to predict the efficiency of the associated airport. Based upon regression models, these efficiency measurements can be used as a diagnostic for improving the efficiency of the entire United States airspace, on a systemic basis, at the individual airport configuration level. An example analysis using this diagnostic is derived in the course of the development and description of the diagnostic and two additional case studies are presented.

Segmentation of human head on medical images is an important process in a wide array of applications such as diagnosis, facial surgery planning, prosthesis design, and forensic identification. In this study, a new Bayesian method for segmentation of facial tissues is presented. Segmentation classes include muscle, bone, fat, air and skin. The method incorporates a model to account for image blurring during data acquisition, a prior helping to reduce noise as well as a partial volume model. Regularization based on isotropic and directional Markov Random Field priors are integrated to the algorithm and their effects on segmentation accuracy are investigated. The Bayesian model is solved iteratively yielding tissue class labels at every voxel of an image. Sub-methods as variations of the main method are generated by switching on/off a combination of the models. Testing of the sub-methods are performed on two patients using single modality three-dimensional (3D) images as well as registered multi-modal 3D images (Magnetic Resonance and Computerized Tomography). Numerical, visual and statistical analyses of the methods are conducted. Improved segmentation accuracy is obtained through the use of the proposed image models and multi-modal data. The methods are also compared with the Level Set method and an adaptive Bayesiansegmentation method proposed in a previous study.