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Les rendements de fission sont des données importantes pour les applications nucléaires ainsi que pour les modèles théoriques qui cherchent à reproduire ces distributions. Les rendements des produits de fission légers pour de nombreux noyaux ont été mesurés par le passé sur le spectromètre Lohengrin. Mais la méthode expérimentale utilisée, détection par chambre à ionisation, ne permet pas la séparation des isotopes pour les produits de fission lourds. Pour valider la méthode dans cette région et compléter les bibliothèques, les rendements isobariques de l’235U(nth,f), du 239Pu(nth,f) et du 241Pu(nth,f) ont été mesurés. La mise en place d’un nouveau dispositif de détection gamma sur le spectromètre a permis de déterminer les rendements isotopiques du 239Pu(nth,f). De plus les distributions en charge ionique et en énergie cinétique des produits de fission ont été étudiées, et ont mis en évidence la présence d'isomères nanosecondes pour certains de ces noyaux. / In spite of the huge amount of fission yield data available in different libraries, more accurate values are still needed for nuclear energy applications and to improve our understanding of the fission process. Thus measurements of fission yields were performed at the mass spectrometer Lohengrin at the Institut Laue-Langevin in Grenoble, France. The mass separator Lohengrin is situated at the research reactor of the institute and permits the placement of an actinide layer in a high thermal neutron flux. It separates fragments according to their atomic mass, kinetic energy and ionic charge state by the action of magnetic and electric fields. Coupling with a high resolution ionization chamber the experiment was used to investigate the mass and isotopic yields in the light mass region. Almost all fission yields of isotopes from Th to Cf have been measured at Lohengrin with this method. It has been extended in this work to the heavy mass region for the reactions 235U(nth,f), 239Pu(nth,f) and 241Pu(nth,f). For these higher masses an isotopic separation is no longer possible. That is why a new method was undertaken with the reaction 239Pu(nth,f) to determine the isotopic yields by gamma spectrometry. During these experiments the ionic charge state and kinetic energy distributions have been measured. Nanosecond isomers have been discovered for some nuclei thanks to a non gaussian charge state distribution. The kinetic energy distributions present very interesting structures which have been also discussed.

Ce mémoire de thèse présente le développement de la méthode «statistical modal energy distribution analysis (SmEdA)» pour des systèmes vibro-acoustiques couplés. Cette méthode de calcul est basée sur le bilan énergétique dans des sous-systèmes fermés couplés, comme une structure ou une cavité. L’interaction entre de tels systèmes est décrite par des couplages entre les modes. La version initiale de SmEdA prend en compte seulement les modes qui ont une fréquence propre dans le bande d’excitation. Le travail présenté ici étudie l’effet des modes non résonants sur la réponse et identifie les cas dans lesquels un tel effet devient important. L’introduction des modes non résonants permet d’utiliser la méthode SmEdA dans des cas d’applications plus larges. En outre, une nouvelle méthode de post-traitement a été développée pour calculer des distributions d'énergie dans les sous-systèmes. Finalement, une nouvelle méthode d'approximation pour la prise en compte des modes de systèmes de grandes dimensions ou mal définis a été formulée. Toutes ces méthodes ont été comparées avec d’autres méthodes de calcul via des exemples académiques et industriels. Ainsi, la nouvelle version de SmEdA incluant le post-traitement pour obtenir des distributions d'énergie a été validé et les avantages et possibilités d'applications sont montrés. / This dissertation presents the further development of the statistical modal energy distribution analysis (SmEdA) for vibro-acoustic coupled problems. This prediction method is based on the energy balance in bounded coupled subsystems, like a structure or a cavity. The interaction between such subsystems is described by mode-to-mode coupling. The original SmEdA formulation takes into account only the modes having the eigenfrequencies within the excitation band. The present work investigates the effect of non resonant modes to the response and identifies cases in which such an effect becomes important. The inclusion of non resonant modes has thus resulted in a new SmEdA formulation which can be used in extended applications. Furthermore, a new post-processing method has been developed to predict energy distribution within subsystems. Finally a novel approximation method for handling modes of huge or ill-defined systems has been formulated. All these methods have been compared to other prediction methods via academic and industrial examples. In this way, the extended SmEdA approach including the post-processing for energy distribution has been validated and its advantages and application possibilities have been demonstrated.

Este trabalho tem por objetivo desenvolver uma abordagem fuzzy focando na estimação de curto prazo da demanda de potência ativa de um alimentador de sistema de distribuição de energia elétrica. A motivação para este trabalho encontra-se na redução do erro de estimação para que o sistema de distribuição como um todo seja corretamente operado. O destaque da abordagem desenvolvida é a metodologia de seleção de entradas para o sistema de estimação, que o treina fornecendo-lhe informações não redundantes e não desnecessárias sobre o comportamento da série temporal. Os resultados, obtidos com treinamento e teste de um sistema de inferência fuzzy multicamadas, mostram que as estimações realizadas selecionando as entradas do sistema de forma criteriosa apresentam menor erro que quando não há critério de seleção. Conclui-se então que a metodologia foi funcional e eficiente para o caso estudado, o que faz com que este trabalho resulte em válidas contribuições nas áreas de sistemas inteligentes, de sistemas dinâmicos e inclusive na forma metodológica de especificação de modelos de estimação de séries temporais. / This work aims to develop a fuzzy approach focusing on the short-term active power demand forecast in a feeder of an electrical energy distribution system. This work motivation lies on the reduction of the forecast error so that the whole distribution system can be correctly operated. The highlight of the developed approach is the methodology to select the inputs for the estimation system, which trains it giving to it non-redundant and non-unnecessary information about the time series behavior. The results, obtained by training and testing a multilayer fuzzy inference system, show that the estimations made by following a criterion to select the inputs have smaller error than when there is no selection criterion at all. It is therefore concluded that the methodology was functional and efficient for the case under study, what makes this work result in valid contributions for the fields of intelligent systems, dynamic systems and in the methodological way to specify models to estimate time series.

Zellen enthalten zahlreiche Enzyme, deren Reaktionen von molekularem Sauerstoff abhängen. Oft sind deren aktive Zentren tief im inneren des Proteins verborgen, was die Frage nach spezifischen Zugangskanälen, die den Sauerstoff gezielt zum Ort der Katalyse leiten, aufwirft. In der vorliegenden Arbeit wird dies am Beispiel der 12/15-Lipoxygenase, als ein typisches Beipiel Sauerstoff verbrauchender Enzyme, untersucht. Die Sauerstoffverteilung innerhalb des Proteins wurde bestimmt und mögliche Routen für den Sauerstoffzugang definiert. Zu diesem Zweck wurden theoretische Untersuchungen eng mit Experimenten verzahnt. Zuerst wurden Molekulardynamik Simulationen des Proteins in Lösung durchgeführt. Aus den Trajektorien konnte die dreidimensionale Verteilung der Freien Enthalpie für Sauerstoff berechnet werden. Die Analyse der günstigsten Pfade in dieser Energielandschaft führte zur Identifikation von vier Sauerstoffkanälen im Protein. Alle Kanäle verbinden die Proteinoberfläche mit einem Gebiet hoher Sauerstoffaffinität am aktiven Zentrum. Diese Region liegt bezüglich des Substrats gegenüber dem Eisenzentrum, wodurch eine strukturelle Erklärung für die Reaktionsspezifität des Enzyms gegeben ist. Der katalytisch bedeutsamste Weg des Sauerstoffs kann durch L367F Austauschmutation blockiert werden, was zu einer stark erhöhten Michaelis-Konstante für Sauerstoff führt. Diese experimentell nachgewiesene Blockade konnte, mit Hilfe entsprechender Molekulardynamik Simulationen, durch eine Umordnung eines Wasserstoffbrücken-Netzwerks von Wassermolekülen innerhalb des Protein im Detail erklärt werden. Die Ergebnisse ermöglichen den Schluss, dass die Hauptroute für Sauerstoff zum aktiven Zentrum des Enzyms einem Kanal folgt, der aus vorübergehend verbundenen Hohlräumen besteht. Hierbei unterliegt das Öffnen und Schließen des Kanals der Dynamik der Proteinseitenketten. / Cells contain numerous enzymes utilizing molecular oxygen for their reactions. Often, their active sites are buried deeply inside the protein which raises the question whether there are specific access channels guiding oxygen to the site of catalysis. In the present thesis this question is investigated choosing 12/15-lipoxygenase as a typical example for such oxygen dependent enzymes. The oxygen distribution within the protein was determined and potential routes for oxygen access were defined. For this purpose an integrated strategy of structural modeling, molecular dynamics simulations, site directed mutagenesis, and kinetic measurements has been applied. First, molecular dynamics simulations of the protein in solution were performed. From the trajectories, the 3-dimensional free-energy distribution for oxygen could be computed. Analyzing energetically favorable paths in the free-energy map led to identification of four oxygen channels in the protein. All channels connect the protein surface with a zone of high oxygen affinity at the active site. This region is localized opposite to the non-heme iron providing a structural explanation for the reaction specificity of this lipoxygenase isoform. The catalytically most relevant path can be obstructed by L367F exchange which leads to a strongly increased Michaelis constant for oxygen. This experimetally proven blocking mechanism can, by virtue of molecular dynamics studies, be explained in detail through a reordering of the hydrogen bonding network of water molecules. As a conclusion, the results provide strong evidence that the main route for oxygen access to the active site of the enzyme follows a channel formed by transiently interconnected cavities whereby the opening and closure is governed by sidechain dynamics.

Objective of the present work is a broad investigation of the so called "target poisoning" during magnetron deposition of TiN in an Ar/N2 atmosphere. Investigations include realtime in-situ ion beam analysis of nitrogen incorporation at the Ti sputter target during the deposition process and the analysis of particle uxes towards and from the target by means of energy resolved mass spectrometry. For experiments a planar, circular DC magnetron, equipped with a 2 inch titanium target was installed in an ultrahigh vacuum chamber which was attached to the beam line system of a 5 MV tandem accelerator. A manipulator allows to move the magnetron vertically and thereby the lateral investigation of the target surface. During magnetron operation the inert and reactive gas flow were adjusted using mass flow controllers resulting in an operating pressure of about 0.3 Pa. The argon flow was fixed, whereas the nitrogen flow was varied to realize different states of target poisoning. In a fi?rst step the mass spectrometer was used to verify and measure basic plasma properties e.g. the residual gas composition, the behavior of reactive gas partial pressure, the plasma potential and the dissociation degree of reactive gas molecules. Based on the non-uniform appearance of the magnetron discharge further measurements were performed in order to discuss the role of varying particle fluxes across the target during the poisoning process. Energy and yield of sputtered particles were analyzed laterally resolved, which allows to describe the surface composition of the target. The energy resolving mass spectrometer was placed at substrate position and the target surface was scanned by changing the magnetron position correspondingly. It was found, that the obtained energy distributions (EDF) of sputtered particles are influenced by their origin, showing signi?ficant differences between the center and the erosion zone of the target. These results are interpreted in terms of laterally different states of target poisoning, which results in a variation of the surface binding energy. Consequently the observed energy shift of the EDF indicates the metallic or already poisoned fraction on target surface. Furthermore the EDF's obtained in reactive sputtering mode are broadened. Thus a superposition of two components, which correspond to the metallic and compound fractions of the surface, is assumed. The conclusion of this treatment is an discrete variation of surface binding energy during the transition from metallic to compound target composition. The reactive gas target coverage as derived from the sputtered energy distributions is in reasonable agreement with predictions from model calculations. The target uptake of nitrogen was determined by means of ion beam analysis using the 14N(d, )12C nuclear reaction. Measurements at varying nitrogen gas flow directly demonstrate the poisoning eff?ect. The reactive gas uptake saturates at a maximum nitrogen areal density of about 1.1016 cm-2 which corresponds to the stoichiometric limit of a 3 nm TiN layer. At sufficiently low reactive gas flow a scan across the target surface discloses a pronounced lateral variation of target poisoning, with a lower areal density in the target race track compared to the target center and edge. Again the findings are reproduced by model calculations, which confirm that the balance of reactive gas injection and sputter erosion is shifted towards erosion in the race track. Accomplished computer simulations of the reactive sputtering process are similar to Berg's well known model. Though based on experimental findings the algorithm was extended to an analytical two layer model which includes the adsorption of reactive gas as well as its different kinds of implantation. A distribution of ion current density across the target diameter is introduced, which allows a more detailed characterization of the processes at the surface. Experimental results and computer simulation have shown that at sufficiently low reactive gas flow, metallic and compound fractions may exist together on the target surface, which is in contradiction to previous simulations, where a homogeneous reactive gas coverage is assumed. Based on the results the dominant mechanisms of nitrogen incorporation at different target locations and at varying reactive gas admixture were identified. / Gegenstand der Arbeit ist die Untersuchung der Targetvergiftung beim reaktiven Magnetronsputtern von TiN in Argon-Sticksoff Atmosphäre. Die Untersuchungen beinhalten die Echtzeit in-situ Ionenstrahlanalyse des Stickstoffeinbaus in das Titantarget während des Depositionsprozesses sowie die Analyse der Teilchenflüsse vom – und hin zum Sputtertarget mittels energieaufgelöster Massenspektrometrie. Das Magnetron wurde in einer Vakuumkammer installiert, welche an die Beamline des 5 MV Tandembeschleunigers angeschlossen war. Die Position des Magnetrons konnte mittels eines Manipulator verändert werden, was die laterale Untersuchung der Targetoberfläche ermöglichte. Während des Magnetronbetriebes wurde der Argonfluss in die Kammer konstant gehalten, während der Stickstofffluss variiert wurde um verschiedene Ausprägungen der Targetvergiftung zu erreichen. In einem ersten Schritt wurden die Eigenschaften des Plasmas, z.B. die Zusammensetzung des Sputtergases, das Verhalten des Reaktivgaspartialdruckes, das Plasmapotenzial und der Dissoziationsgrad der Reaktivgasmoleküle im Plasma, mit dem Massenspektrometer ermittelt. Aufgrund der ungleichmäßigen Gasentladung vor dem Magnetrontarget, wurden auch lateral variierende Teilchenflüssen und eine ungleichmäßige Targetvergiftung angenommen. Die Energie und die Ausbeute von gesputterten Teilchen wurde deshalb lateral aufgelöst untersucht. Das Massenspektrometer wurde zu diesem Zweck am Ort des Substrates positioniert und die Targetoberfläche konnte gescannt werden indem die Magnetronposition verändert wurde. Die so aufgenommenen Energieverteilungen der gesputterten Teilchen zeigen eine räumliche Abhängigkeit. Teilchen die aus dem Targetzentrum stammen unterscheiden sich hinsichtlich ihrer Energie signifikant von den Teilchen die in der Target-Erosionszone gesputtert werden. Dieses Resultat zeigt die ungleichmäßige Targetvergiftung, wodurch es zu einer Veränderung der Oberflächenbindungsenergie kommt. Über die Verschiebung in der Energieverteilung lässt sich somit der Zustand der Targetoberfläche beschreiben. Diese experimentellen Ergebnisse zeigen Übereinstimmung mit den Ergebnissen der Modellrechnungen. Der Stickstoffgehalt des Targets wurde weiterhin mittels Ionenstrahlanalyse (NRA) bestimmt. Messungen bei verschiedenen Stickstoffflüssen demonstrieren direkt die Vergiftung des Targets. Die maximale Stickstoffkonzentration sättigt bei einem Wert, der dem Stickstoffgehalt in einer ca. 3 nm dicken Titannitridschicht entspricht. Bei ausreichend niedrigem Stickstofffluss zeigt die Messung quer über den Targetdurchmesser eine Variation im Stickstoffgehalt. Die Stickstoffkonzentration in der Erosionszone ist deutlich geringer als im Targetzentrum oder am Targetrand. Die Resultate wurden wiederum durch Modellrechnungen bestätigt. Die durchgeführten Computersimulationen basieren auf Sören Bergs Modell des reaktiven Sputterprozesses. Der Algorithmus wurde jedoch auf der Basis der experimentellen Ergebnisse erweitert. Das Modell beinhaltet nun Mechanismen des Reaktivgaseinbaus in das Target, wie Adsorption, Implantation und Recoilimplantation. Des Weiteren wurde die Ionenstromverteilung als Funktion des Targetdurchmessers in das Modell aufgenommen, was eine detailliertere Beschreibung des Prozesses ermöglicht. Die experimentellen Ergebnisse und die Resultate der Computersimulation zeigen, dass bei niedrigen Reaktivgasflüssen metallische und vergiftete Bereiche auf der Targetoberfläche gemeinsam existieren. Das ist im Widerspruch zu älteren Simulationen, in denen von einer homogenen Targetbedeckung durch das Reaktivgas ausgegangen wird. Basierend auf den Ergebnissen wurden die dominierenden Mechanismen des Reaktivgaseinbaus in das Sputtertarget, in Abhängigkeit von der Position und von der Sputtergaszusammensetzung, identifiziert.

Submitted by Cristhiane Guerra (cristhiane.guerra@gmail.com) on 2017-01-26T14:55:17Z No. of bitstreams: 1 arquivototal.pdf: 2586746 bytes, checksum: 18b7b08875fbe9dc7bcecd5595b19734 (MD5) / Made available in DSpace on 2017-01-26T14:55:17Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2586746 bytes, checksum: 18b7b08875fbe9dc7bcecd5595b19734 (MD5) Previous issue date: 2016-07-29 / The demand forecasting studies are of great importance for electricity companies, because there is a need to allocate their resources well in advance, requiring a medium and long- term p lanning. These resources can be the purchase of new equipment, the transmission line acquisition or construction, scheduled maintenance and the purchase and sale of energy. I n this work, a support tool has been developed for experts in strategic planning i n power distribution systems using artificial neural networks to demand forecasting. For the proposed method, it implemented a demand forecasting procedure in the medium term of the region fueled by three substations belonging to the power distribution sys tem managed by EnergisaPB, using a computer model based on Multilayer Perceptron (MLP) artificial neural networks with the assistance of Matlab ® environment. The database was structured by the measurements of active power from 2008 to 2014, provided by En ergisa/PB and the forecast achieved one year ahead (52 weeks) compared with the real data of 2014. In addition, it was possible to evaluate the performance of RNA and estimate the demand growth in the region supplied by each substation, which can assist th e distribution system expansion planning. / Os estudo s de previsão de demanda têm grande importância para empresa s da área de energia elétrica , pois, existe a necessidade de alocar seus recursos com uma certa antecedência , exigindo um planejamento a médio e longo prazo. D entre estes recursos , estão a compra de equipamentos, a aquisição e construção de linhas de transmissão, manutenções programadas e a compra e venda de energia. Nesta premissa, foi desenvolvida uma ferramenta de apoio aos especialistas na área de planejamento estratégico em sistemas de distrib uição de energia elétrica, utilizando redes neurais artificiais para previsão de demanda. Para o método proposto, foi implementado um procedimento de previsão de demanda no médio prazo da região alimentada por três subestações reais pertencentes ao sistema de distribuição de energia gerido pela concessionária Energisa- PB, utilizando um modelo computacional baseado em redes neurais artificiais (RNA) do tipo Multilayer Perceptron (MLP) com o auxílio do ambiente Matlab ® . Foram consideradas as informações reais (banco de dados) da potência ativa, para o período de 2008 até 2014, fornecidas pela própria concessionária e a previsão alcançou o horizonte de um ano a frente (52 semanas). A RNA foi treinada com os dados de 2008 a 2013, e o resultado, comparado com dad os do ano de 2014. Além disso, foi possível avaliar o desempenho da RNA sob diferentes aspectos (volume de treinamento, parâmetros, configurações, camadas ocultas, etc.) e estimar o crescimento de demanda da região alimentada por cada subestação, o que pod e auxiliar o planejamento de expansão do sistema de distribuição.

Made available in DSpace on 2014-07-29T15:08:22Z (GMT). No. of bitstreams: 1 Adson.pdf: 1251737 bytes, checksum: 08b3122009f15a40cec4f32fda3231e9 (MD5) Previous issue date: 2008-11-07 / The present work deals with the problem of planning the distribution system of electricity and is divided into three parts: Problem Definition, Resolution Approaches and Results and Conclusions. The energy distribution networks are of great economic importance in countries like Brazil. On one hand, there are fixed costs of physical installation and operation of the network, mainly due to the costs of energy losses and, secondly, the natural obstacles along the possible passages of network s links. The large amount of these costs, together with lack of efficient methods when it comes to real applications in the matter, justify the development of this research. The study of such aspects, the precise definition of the problem and the reasons that motivated this work can be found on the first part of this work. The second part shows the approaches for resolution. Three proposals methods were adopted: the first uses the algorithm Prim associated with the method Nelder-Mead Simplex. In the second proposal uses Dynamic Programming and, finally, we take the metaphor of Ant Colony also associated with the Nelder-Mead Simplex. The results, presented at the third part of this work, demonstrated the effectiveness of the proposed methods, especially the good compromise between performance and applicability obtained by the third proposal. / O presente trabalho lida com o problema de planejamento da rede de distribuição de energia elétrica, estando dividido em três partes: Definição do Problema, Abordagens de Resolução e Resultados e Conclusões. As redes de distribuição de energia têm uma grande importância econômica em países como o Brasil. Por um lado, há os custos físicos fixos de instalação e de operação da rede, sobretudo os custos devido às perdas de energia e, por outro, os obstáculos naturais impostos ao longo das possíveis passagens para as ligações da rede. O montante elevado destes custos, unidos à escassez de métodos eficientes quando se trata de aplicações reais no assunto, justificam o desenvolvimento desta pesquisa. O estudo de tais aspectos, a definição precisa do problema e as justificativas podem ser encontradas na primeira parte deste trabalho. Na segunda parte, apresentam-se as abordagens de resolução. Três propostas foram adotadas: na primeira usa-se o algoritmo Prim associado ao método Nelder-Mead Simplex. Na segunda proposta utiliza-se a Programação Dinâmica e, por fim, tomamos a metáfora de colônia de formigas também associada ao Nelder-Mead Simplex. Os resultados, apresentados na terceira parte deste trabalho, mostram a eficácia dos métodos propostos, em especial o bom compromisso entre performance e aplicabilidade obtido pela terceira proposta.

Magister Scientiae - MSc / We investigate the modelling of radio galaxies within a semi-analytic framework in the Millennium Simulation of the Virgo Consortium. The aim is to assess the radio sources contamination of Sunyaev-Zeldovich (SZ) signatures of clusters of galaxies in Cosmic Microwave Background (CMB) experiments. The modelling is also relevant to the Karoo Array Telescope (MeerKAT) and the Square Kilometre Array (SKA) science. The semi-analytical model consists of N-body simulation, the Millennium Run to trace the merger history of dark matter haloes within the Λ Cold Dark Matter (ΛCDM) cosmology and a follow up of the black hole accretion history and Active Galactic Nuclei (AGN) evolution. We study the growth of the supermassive black hole (SMBH) in galaxy centres and determine the black hole mass accretion conversion into radiation. We identify a model which matches observed radio luminosity function. We describe a model of observed sample of radio surveys at a given frequency and a flux density limit to obtain a model of radio luminosity function (space density of radio sources as a function of redshift) that we compare with our simulated data. We determine the redshift distribution of radio galaxies (FRI), blazars and radio quasars (FRII) in the simulation. We focus the modelling on flat spectrum population of blazars since their jets are collimated towards us and thus constitute the most potential contaminants of the CMB. We determine the spatial and density distribution of radio sources in clusters with a virial mass Mvir 2 1014h−1M and then compute the temperature fluctuations and fluxes produced by these cluster radio sources. Our main results include: the model provides a reasonable match within uncertainties with the model obtained by Dunlop & Peacock (1990) [39] using their best fit of radio luminosity function at redshift z . 0:3. The model underestimates the number of radio sources at high redshift z & 1. Radio sources are concentrated around the centre of clusters with a maximum density at r . 0:1r200 where r200 is the radius within which the density is 200 times the critical density. Radio sources are more concentrated in low mass clusters. The model predicts a surface density profile of radio sources with luminosity P 1023 W.Hz−1 at 1.4 GHz (z . 0:06) in agreement with that of Lin & Mohr (2007) [58] at r . 0:1r200 but underestimates the density in the outskirts of the clusters. BL Lacs and FRI radio galaxies produce non negligible contamination at redshift z . 0:1. They produce a mean temperature fluctuation 4:5 K at redshift z 0:01 which can be at the same level as the kinetic SZE signal produced by the cluster. Blazars constitute potential contaminant of the thermal SZ effect at redshift z 1:0 and z 1:5 at 145 GHz where they produce a mean temperature 300 K - 350 K for an average mass of the cluster. / South Africa

Este trabalho tem por objetivo desenvolver uma abordagem fuzzy focando na estimação de curto prazo da demanda de potência ativa de um alimentador de sistema de distribuição de energia elétrica. A motivação para este trabalho encontra-se na redução do erro de estimação para que o sistema de distribuição como um todo seja corretamente operado. O destaque da abordagem desenvolvida é a metodologia de seleção de entradas para o sistema de estimação, que o treina fornecendo-lhe informações não redundantes e não desnecessárias sobre o comportamento da série temporal. Os resultados, obtidos com treinamento e teste de um sistema de inferência fuzzy multicamadas, mostram que as estimações realizadas selecionando as entradas do sistema de forma criteriosa apresentam menor erro que quando não há critério de seleção. Conclui-se então que a metodologia foi funcional e eficiente para o caso estudado, o que faz com que este trabalho resulte em válidas contribuições nas áreas de sistemas inteligentes, de sistemas dinâmicos e inclusive na forma metodológica de especificação de modelos de estimação de séries temporais. / This work aims to develop a fuzzy approach focusing on the short-term active power demand forecast in a feeder of an electrical energy distribution system. This work motivation lies on the reduction of the forecast error so that the whole distribution system can be correctly operated. The highlight of the developed approach is the methodology to select the inputs for the estimation system, which trains it giving to it non-redundant and non-unnecessary information about the time series behavior. The results, obtained by training and testing a multilayer fuzzy inference system, show that the estimations made by following a criterion to select the inputs have smaller error than when there is no selection criterion at all. It is therefore concluded that the methodology was functional and efficient for the case under study, what makes this work result in valid contributions for the fields of intelligent systems, dynamic systems and in the methodological way to specify models to estimate time series.