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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Programação dinâmica estocástica com discretização do intercâmbio de energia entre subsistemas hidrotérmicos no problema de planejamento da operação

Conceição, Wellington Carlos da 12 December 2016 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-20T13:40:45Z No. of bitstreams: 1 wellingtoncarlosdaconceicao.pdf: 4259949 bytes, checksum: 52410bbb422df8d4e80e7f6956efc71e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-21T13:12:55Z (GMT) No. of bitstreams: 1 wellingtoncarlosdaconceicao.pdf: 4259949 bytes, checksum: 52410bbb422df8d4e80e7f6956efc71e (MD5) / Made available in DSpace on 2017-03-21T13:12:55Z (GMT). No. of bitstreams: 1 wellingtoncarlosdaconceicao.pdf: 4259949 bytes, checksum: 52410bbb422df8d4e80e7f6956efc71e (MD5) Previous issue date: 2016-12-12 / O sistema de produção de energia elétrica brasileiro é um sistema hidrotérmico de grande porte com forte predominância de usinas hidrelétricas. O planejamento e operação do sistema é realizado considerando diversos fatores, tais como, estocasticidade das afluências, usinas hidrelétricas em cascata e acoplamento temporal da operação. A resolução deste tipodeproblemaéfeitaconsiderandodiversoshorizontesdeplanejamento. Oplanejamento da operação de médio prazo compreende um período de 5 anos de estudo, e este período é discretizado em base mensal. O presente trabalho apresenta uma metodologia alternativa para resolução do problema de planejamento da operação de médio prazo de sistemas hidrotérmicos utilizando a Programação Dinâmica Estocástica (PDE) com discretização dointercâmbiodeenergiaentreossubsistemas(PDE-INT).Alémdisso, utiliza-seatécnica de sistemas equivalentes de energia e o algoritmo de fechos convexos (convex hull) para obtenção da função de custo futuro a partir dos pontos obtidos pela PDE-INT. Nesta abordagem, para cálculo da política energética, os subsistemas são considerados isolados, e desta forma, as variáveis que compõem o espaço de estados que são discretizadas são a energia armazenada e o intercâmbio líquido entre os subsistemas. Inicialmente, para análise e avaliação da metodologia proposta na resolução do problema de planejamento hidrotérmico, criou-se um sistema tutorial, composto por dois subsistemas. Em seguida, a metodologia foi utilizada considerando todo o sistema elétrico brasileiro, representado por quatro subsistemas ou submercados. Os resultados mostraram que com a técnica de separação dos subsistemas há uma redução significativa no tempo computacional quando comparados com as técnicas tradicionais que utilizam programação dinâmica. Desta forma, a metodologia proposta pode ser utilizada para uma análise rápida e inicial do caso em estudo, servindo como base para estudos e refinamentos posteriores. / The Brazilian power production system is a large scale hydrothermal system with a strong predominance of hydroelectric power plants. The electric power system operation planning must take into consideration several factors, such as uncertainty of the water inflows, hydroelectric plants in cascade and temporal coupling. This problem is solved considering different planning horizon. The long-term operation planning problem is generally solved by a chain of computational models that consider a period of 5 years ahead with monthly discretization. This work presents an alternative strategy to solve hydrothermalsystemsoperationplanningbyStochasticDynamicProgramming(SDP)with discretization of energy interchange between subsystems (SDP-INT). Under the presented approach, the hydroelectric plants are grouped into energy equivalent subsystems and the expected operation cost functions are modeled by a piecewise linear approximation, by means of the convex hull algorithm. Also, under this methodology, the subsystems are solved isolated, but the net energy interchange (export – import) between subsystems is set as a state variable of the cost function, together with the energy storage Initially, for the analysis and evaluation of the proposed methodology applied on solving the hydrothermalplanningproblem, themethodologyisusedinatutorialsystem, composedof two subsystems. Next, a simulation with the whole Brazilian electrical system considering four subsystems is presented. The results have shown that this subsystems separation technique reduces significantly the computation time when compared with the traditional techniques, demonstrating the effectiveness of the proposed methodology. Thus, the proposed methodology can be used for a fast and initial analysis of the case study, serving as a basis for further studies.
182

Nova metodologia para o controle de intercâmbio de potência reativa

Nascimento, Paulo Sérgio de Castro 18 April 2017 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-07-21T13:29:40Z No. of bitstreams: 1 paulosergiodecastronascimento.pdf: 3896961 bytes, checksum: 0b372ca459a14823ea250c1b708376af (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-08T18:15:52Z (GMT) No. of bitstreams: 1 paulosergiodecastronascimento.pdf: 3896961 bytes, checksum: 0b372ca459a14823ea250c1b708376af (MD5) / Made available in DSpace on 2017-08-08T18:15:52Z (GMT). No. of bitstreams: 1 paulosergiodecastronascimento.pdf: 3896961 bytes, checksum: 0b372ca459a14823ea250c1b708376af (MD5) Previous issue date: 2017-04-18 / O Controle de Intercâmbio de Potência Reativa (CIPR) é uma metodologia cujo principal objetivo é manter o intercâmbio de potência reativa de uma área em um determinado valor especificado. Tal esquema tem potencial para subsidiar o estudo do suporte de potência reativa fornecido ou requerido por uma determinada área e seu impacto na operação do sistema. Além disso, tal estratégia de controle foi elaborada visando o desacoplamento de controle de tensão e potência reativa da área, de forma a permitir uma maior eficiência de estratégias de controle coordenado de tensão. A sistemática básica da formulação matemática que será apresentada, foi inspirada especialmente no método de controle de intercâmbio de potência ativa entre áreas, onde múltiplos geradores contribuem para controlar o intercâmbio de potencia ativa em valores especificados, conforme descrito em [1]. A principal contribuição deste trabalho está associada a uma nova formulação aumentada, onde apenas uma equação adicional é utilizada para representação do controle de intercâmbio de potência reativa. A metodologia propicia uma grande flexibilidade, permitindo não só a aplicação no CIPR, mas também na modelagem de outros tipos de controles que necessitam representar vários equipamentos simultaneamente. Para a aplicação deste trabalho, a metodologia representa os vários geradores participantes do CIPR, com acréscimo de apenas uma linha e uma coluna na matriz jacobiana, sendo esta a principal contribuição deste trabalho. Adicionalmente, a metodologia apresenta grande versatilidade na incorporação e/ou retirada dos equipamentos responsáveis pelo controle, representando de forma eficiente as limitações reais dos equipamentos. O modelo matemático proposto foi testado em diversos sistemas testes, obtendo-se bons resultados. As simulações realizadas foram validadas usando o programa Anarede de propriedade do Centro de Pesquisa de Energia Elétrica (CEPEL). Os modelos de fluxo de potência e o núcleo principal da metodologia proposta foram desenvolvidos em MATLAB, auxiliadas por diversos programas para formulação e verificação dos resultados. Sendo os principais destes: Mathematica, Anarede, PSIM, linguagem R, Rstudio. / Reactive Power Interchange Control (RPIC) is a methodology whose main objective is to maintain the reactive power interchange of an area at a specified value. Such a scheme has the potential to support the study of the reactive power support provided or required by a given area and its impact on the operation of the system. In addition, such control strategy was elaborated aiming at the decoupling of tension control and reactive power of the area, in order to allow greater efficiency of coordinated voltage control strategies. The basic mathematical formulation, which will be presented, was inspired by the method of control of active power interchange between areas, where multiple generators contribute to control the active power exchange in specified values, as described in [1]. The main contribution of this work is associated with a new augmented formulation, where only one additional equation is used to represent the reactive power exchange control between two areas. The methodology provides great flexibility, allowing not only the application in the RPIC, but in other to generally model control strategies, in which the contribution of more than one device for a given control strategy is required. For the application of this work, the modelling represents the various generators participating in the RPIC, in which only one additional line and column in the Jacobian matrix is required, being this formulation the main contribution of this work. In addition, the methodology presents great flexibility in the incorporation or removal of a control device, which has reached its corresponding limit. The proposed mathematical model was tested in several test systems, obtaining good results. The simulations were validated using the ANAREDE program owned by the Electric Energy Research Center (CEPEL). The power flow models and the main core of the proposed methodology were developed in MATLAB, aided by several programs for formulating and verifying the results. The main ones being: Mathematica, ANAREDE, PSIM, R language, Rstudio.
183

Sustaining Sustainable Mobility : the Integration of Multimodal Public Transportation in Addis Ababa / Favoriser une mobilité durable : l’intégration du transport public multimodal à Addis Abeba

Hussen, Berhanu Woldetensae 27 May 2016 (has links)
Addis-Abeba, qui s’étend sur 540 km2 et compte 3,1 millions d’habitants, connait aujourd’hui des transformations socio-économiques et spatiales rapides. Elle n’est pas seulement le coeur politique, commercial, économique et financier du pays mais aussi une ville internationale accueillant le siège de l’Union africaine et d’autres institutions internationales. Comme d’autres villes africaines, elle connait un rythme élevé d’urbanisation. Ce processus a impliqué la croissance du nombre d’habitants mais aussi une extension spatiale accrue. En conséquence, la demande de déplacements et la longueur des parcours ont augmenté. Le transport joue ainsi un rôle clé, pesant sur le développement socio-économique et la configuration de l’espace urbain. Tout aussi important, en tant que demande dérivée, il joue sur la capacité des citadins à accomplir leurs diverses activités. La motorisation des ménages restant faible en dépit d’une lente progression, le transport public constitue le principal moyen d’accès à une mobilité motorisée pour la majorité de la population. L’offre est constituée d’une multitude d’opérateurs formels et informels, travaillant selon un schéma artisanal. On estime à plus de 18 000 les véhicules de transport public, la plupart de faible capacité, qui parcourent chaque jour les rues d’Addis-Abeba. En dépit de son importance, le transport public souffre de capacités d’investissement insuffisantes ainsi que, jusqu’à récemment, du manque d’une politique publique claire et affirmée. Il pâtit également de l’absence d’une approche intégrée, pour sa planification, sa gestion et sa mise en oeuvre. De nombreuses villes du Nord, parfois depuis près d’un demi-siècle, ont choisi de construire un service intégré de transport public. L’intégration y est vue comme un outil viable pour offrir un transport urbain de haute qualité et « sans couture », permettant un développement urbain durable. Par contre, les villes africaines, caractérisées par une urbanisation rapide, des taux d’équipement automobile faibles, un système de transport public déficient et des contraintes financières majeures manquent de telles expériences d’intégration du transport public. Notre question est donc : « Comment les villes africaines peuvent-elles reproduire et mettre en oeuvre des politiques d’intégration du transport public ? », originellement développées dans les villes du Nord. La thèse essaie d’apporter des éléments de réponse à cette question. Elle s’appuie sur une analyse des différentes formes d’intégration du transport public. Puis elle propose un schéma de conception et de mise en oeuvre d’un système de transport public intégré, appréhendé comme un outil de mobilité urbaine durable pour Addis-Abeba. / Addis Ababa, with an area of 540 km2 and with population of 3.1 million people is experiencing a rapid pace of socio-economic and physical transformation. The city is not only the political, commercial, economic and financial hub of the country but also an international city serving as the seat of the African Union and various international organizations. Alike many African Cities, Addis Ababa has been undergoing a high rate of urbanization. This process of rapid urbanization has resulted in the increase in the size of the population and the physical expansion of the city. As a consequence, travel demand and length of the trip are increasing. Transportation plays a key role in determining the socioeconomic development and shaping the spatial development framework of the city. Equally important, transportation as derived demand is also a fundamental means for residents to fulfill their various activities. In Addis Ababa motorization, although on the increase, is low and public transportation is the most important mode of motorized mobility for the large majority of the city’s population. There are various formal and informal operators of the public transport mainly operating on individual basis. It is estimated that there are over 18,000 public transport vehicles that are daily running in Addis Ababa, most of them low capacity vehicles. Despite its importance, the public transport sector not only suffers from shortage, insufficient capital investment, and until recently lack of clear governmental policy and leadership but also from the absence of integrated approach to its operation, planning and management.Many cities in the North have embarked on integrating the provision of public transportation for nearly half a century now. In these cities, integration in public transportation has been recommended as a viable instrument for providing high quality and seamless urban transport and enhancing sustainable urban development. African cities which are characterized by their high urbanization rate, low level of private car ownership, deficient public transportation system and significant financial constraints lack public transportation integration experiences. The question is then ‘how do African cities replicate and implement public transport integration practices?’ that have been originally developed for the Cities of the North. The thesis attempts to answer this question and analyses the different forms of public transport integration. It then proposes a framework for implementing integrated public transport as a sustainable means of urban mobility in Addis Ababa.
184

Trust relationships in exchange protocols

Gonzãlez-Deleito Collell, Nicolãs 20 December 2005 (has links)
Les protocoles d'échange d'informations représentent un des grands domaines actuels de recherche en sécurité informatique, et sont entre autres à la base des mécanismes de commerce électronique. Ils sont par exemple nécessaires à la réalisation d'un achat en ligne, à la signature d'un contrat électronique et au courrier électronique recommandé. Dans ces exemples, les échanges d'informations consistent à échanger respectivement un objet électronique contre un paiement, des signatures digitales sur un même contrat, et un courrier électronique contre un accusé de réception.<p><p>Informellement, un protocole mettant en oeuvre de tels types d'échanges est dit équitable si et seulement si à la fin du protocole soit l'échange d'information a eu lieu, soit aucune information (même en partie) n'a été échangée. Afin d'assurer cette propriété d'équité de manière efficace, et d'éviter ainsi des éventuels comportements malhonnêtes de la part des participants à l'échange d'informations qui chercheraient à nuire au bon déroulement du protocole, une tierce partie de confiance est utilisée.<p><p>Un des buts de cette thèse est de discerner les tâches devant être assurées par une telle tierce partie de confiance et développer des méthodes permettant d'en minimiser le nombre et l'importance, afin de limiter la confiance que les entités effectuant l'échange doivent porter à cette tierce partie. Pour cela, nous identifions tout d'abord de manière générique quels sont ces types de tâches, puis nous analysons sous ce point de vue les principaux protocoles ayant été proposés dans la littérature.<p><p>Cette démarche nous conduit ensuite naturellement à nous pencher sur les relations de confiance entre les participants à un protocole d'échange. Ce type de relations est particulièrement significatif pour des protocoles à plus de deux participants.<p><p>Enfin, dans ce travail, nous observons à la lumière des aspects de confiance, les différentes propriétés propres aux protocoles d'échange, et nous proposons plusieurs nouveaux protocoles ayant des besoins en confiance limités.<p> / Doctorat en sciences, Spécialisation Informatique / info:eu-repo/semantics/nonPublished
185

Utility computing: Certification model, costing model, and related architecture development

Faruqui, Saif Ahmed 01 January 2005 (has links)
The purpose of the thesis was to propose one set of solutions to some of the challenges that are delaying the adoption of utility computing on a wider scale. These components enable effective deployment of utility computing, efficient look-up, and comparison of service offerings of different utility computing resource centers connected to the utility computing network.
186

Studie mimoúrovňové křižovatky MÚK Brno Východ / Technical study of the interchange Brno - East

Marušák, Lubomír January 2018 (has links)
This thesis deals with the modification of the interchange of motorway D1 in Brno – east (km 203). It’s aim to design an optimal solution for omnidirectional connection on the road I/50. Currently it has the shape of a letter Y which allows only a two-way ride. Further, the aim is to propose the connection of the road II/430 to the road junctions. Part of this thesis is proposal to extend the motorway to a six-lane in the place of interchange due to capacity utilization. For this thesis was chosen one from four concepts of the junction within the scope of the study. The work is complemented by a tradic survey on the current arrangement which was carried out using statistical radars.
187

Autobusové nádraží ve variantě ŽUB A-Řeka / Coach station by the Brno River railway station

Pelc, Norbert January 2019 (has links)
This diploma thesis deals with a design of the coach station in option A-River of the Brno railway hub. The aim of the thesis is alternative design of the coach station configuration located under the bridge of the new passenger’s railway station. Furthermore, the proof of coach station Zvonařka preservation has been given in accordance with the estate road system change in relation with the new railway infrastructure development. The preliminary design is processed in four options. The complement of this thesis is a traffic survey.
188

Vyloučení úrovňového železničního přejezdu na železniční trati č.300 s ulicí Kaštanovou v Brně / Exclusion of the road crossing the railway line no.300 with Kaštanová street in Brno

Budina, Martin January 2014 (has links)
The aim of this thesis is to design an exclusion of the road crossing the railway line no.300 with Kaštanová street in Brno. A ring road-based solution is proposed. Planned doubling of railway line, as mentioned in the feasibility study of SJKD, was taken into account. The new railway station Brněnské Ivanovice is designed, which will together with public transport bus services create an interchange station. The project also includes a newly designed routes for pedestrians.
189

Západní obchvat Pelhřimova / Bypass Pelhřimov west

Dočkal, Pavel January 2015 (has links)
Final thesis deals with relocation of road I/34, specifically bypass Pelhřimov west. The crossing with roads I/19 and I/112 is solved by interchange roundabout in nothern part of bypass. Reason of construction is unification road I/34, which is a part of the international route E551, to category S11,5/70. The principal tasks was to keep it in the land use plan and the effort to maximize the alignment of volumes of earthworks.
190

Laický překlad u českých krajanů v Argentině / Fan translation of the Czech ex-patriots in Argentina

Režová, Markéta January 2021 (has links)
(in English): The aim of the present thesis is to investigate and describe the role of non-professional translation and interpreting between Spanish and Czech in the intercultural communication, whose actors were and are Czech compatriots in Argentina. The two introductory parts of the thesis provide a summary on the historical context of the Czech emigration to Argentina and about the language situation of Czech compatriots in Argentina. The theoretical part is based on the sociological turn in translation studies, on the focus on the translator and the history of translation and translators. Methodologically, the thesis is based primarily on archival research and oral history. The empirical part maps the occurrence of amateur translations in our corpus, further, it draws attention to some larger translations made by compatriots and, last but not least, it gathers information about non-professional interpreting in the Czech compatriot communities in Argentina. As a conclusion, the found information is summarized and further possibilities of linguistic research of the Czech compatriot communities in Argentina are proposed.

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