• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 91
  • 33
  • 11
  • 7
  • 5
  • 5
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 200
  • 29
  • 25
  • 21
  • 20
  • 17
  • 16
  • 16
  • 15
  • 15
  • 14
  • 14
  • 13
  • 13
  • 13
  • 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

Processamento de erros grosseiros através do índice de não-detecção de erros e dos resíduos normalizados / Bad data processing through the undetectability index and the normalized residuals

Camila Silva Vieira 20 October 2017 (has links)
Esta dissertação trata do problema de processamento de Erros Grosseiros (EGs) com base na aplicação do chamado Índice de Não-Detecção de Erros, ou apenas UI (Undetectability Index), na análise dos resíduos do estimador de estado por mínimos quadrados ponderados. O índice UI foi desenvolvido recentemente e possibilita a classificação das medidas de acordo com as suas características de não refletirem grande parcela de seus erros nos resíduos daquele estimador. As medidas com maiores UIs são aquelas cujos erros são mais difíceis de serem detectados através de métodos que fazem uso da análise dos resíduos, pois grande parcela do erro dessas medidas não aparece no resíduo. Inicialmente demonstrou-se, nesta dissertação, que erros das estimativas das variáveis de estado em um sistema com EG não-detectável (em uma medida de alto índice UI) podem ser mais significativos que em medidas com EGs detectáveis (em medidas com índices UIs baixos). Justificando, dessa forma, a importância de estudos para tornar possível o processamento de EGs em medidas com alto índice UI. Realizou-se, então, nesta dissertação, diversas simulações computacionais buscando analisar a influência de diferentes ponderações de medidas no UI e também nos erros das estimativas das variáveis de estado. Encontrou-se, então, uma maneira que destacou-se como a mais adequada para ponderação das medidas. Por fim, ampliaram-se, nesta dissertação, as pesquisas referentes ao UI para um estimador de estado por mínimos quadrados ponderados híbrido. / This dissertation deals with the problem of Gross Errors processing based on the use of the so-called Undetectability Index, or just UI. This index was developed recently and it is capable to classify the measurements according to their characteristics of not reflecting their errors into the residuals of the weighted least squares state estimation process. Gross errors in measurements with higher UIs are very difficult to be detected by methods based on the residual analysis, as the errors in those measurements are masked, i.e., they are not reflected in the residuals. Initially, this dissertation demonstrates that a non-detectable gross error (error in a measurement with high UI) may affect more the accuracy of the estimated state variables than a detectable gross error (error in a measurement with low UI). Therefore, justifying the importance of studies that make possible gross errors processing in measurements with high UI. In this dissertation, several computational simulations are carried out to analyze the influence of different weights of measurements in the UI index and also in the accuracy of the estimated state variables. It is chosen a way that stood out as the most appropriate for weighing the measurements. Finally, in this dissertation, the studies referring to the UI is extended for a hybrid weighted least squares state estimator.
182

Incid??ncia do IPTU sobre bens im??veis p??blicos ocupados por empresas privadas: uma an??lise cr??tica da materialidade constitucional do imposto e suas rela????es com a imunidade tribut??ria rec??proca (Tema 437 da Repercuss??o Geral do STF)

Ganem, Bruna Ribeiro 15 December 2015 (has links)
Submitted by Kelson Anthony de Menezes (kelson@ucb.br) on 2017-01-09T11:10:46Z No. of bitstreams: 1 BrunaRibeiroGanemDissertacaoParcial2015.pdf: 952390 bytes, checksum: b9f45d5295e02005f556c040f27bb147 (MD5) / Made available in DSpace on 2017-01-09T11:10:46Z (GMT). No. of bitstreams: 1 BrunaRibeiroGanemDissertacaoParcial2015.pdf: 952390 bytes, checksum: b9f45d5295e02005f556c040f27bb147 (MD5) Previous issue date: 2015-12-15 / This is a critical paper about the incidence of Real State Tax, a municipal tax, in cases where immovable properties and assets held by Federal or States Government are occupied by particular persons, as result of legal use concession contracts or authorized occupation, and its connections with the Mutual Tax Immunity. To achieve these aims, therefore, this study solved the following research problems: in first place, confirmation of the partial unconstitutionality of the National Tax Code in relation to the Constitution of 1946 and its non reception by the current Federal Constitution (1988); construction of the normative matrix rule of the studied tax, since the constitutional level, passing throw the complementary legal settlement, until the local legislation, study that resulted in a doctrinal refinement of the analyzed institute, specially, on its material, personal e quantitative criterions; and, in second place, implications of the Mutual Tax Immunity on the definition of the taxpayer subject, considering the impossibility of transferring the payment responsibility to a non-taxable person, such as the occupant of the public property covered by a concession contract. Furthermore, this research analyzed the Mutual Tax Immunity under the Article 150, VI, ???a???, of the Federal Constitution, in order to identify if it grants a absolute status of protection against the taxation, or if it can be relaxed in cases where the Public Person explore remunerate economic activities. These subjects are under judgment by the Brazilian Supreme Court in the Leading Case number 473 of the general repercussion. Finally, from the theory of the fundamental rights of Robert Alexy, pondering and weighing were developed in order to solve the conflict between the involved constitutional principles: the Free Competition as a key element of an open market economy; and the Mutual Tax Immunity as a guarantor of the Federation Principle. / O objeto de estudo deste trabalho ?? a an??lise da incid??ncia do Imposto Predial e Territorial Urbano (IPTU) sobre os im??veis p??blicos ocupados por particulares por meio de contratos onerosos de concess??o de direito real de uso. No primeiro cap??tulo, a autora fez uma an??lise hist??ria da evolu????o constitucional do estudado imposto e suas rela????es com o C??digo Tribut??rio Nacional (CTN), que resultou no reconhecimento da inconstitucionalidade material de partes dos artigos 32 e 34 do CTN em face da Constitui????o de 1946, bem como a sua n??o recep????o parcial pela Constitui????o Federal de 1988. No cap??tulo subsequente, a norma tribut??ria do IPTU foi estruturada em seus diversos planos normativos, com a constru????o de suas regras-matrizes constitucional, complementar e local, cujos conte??dos se mostraram conflitantes. O terceiro cap??tulo foi direcionado para a constru????o de uma proposta de solu????o para o Tema 437 da Repercuss??o Geral do Supremo Tribunal Federal, que tem como objeto a verifica????o da possibilidade de manuten????o da imunidade tribut??ria rec??proca dos entes p??blicos nas situa????es em que transferem a posse e o uso de seus bens im??veis para particulares mediante o recebimento de contrapresta????o. Nesse contexto, foi necess??rio analisar se a imunidade em quest??o pode ser afastada em raz??o do car??ter oneroso do contrato, bem como se essa atividade de concess??o de bem im??vel p??blico pode ser considerada como h??bil para interferir na livre concorr??ncia do setor imobili??rio local. Para solucionar essas quest??es, utilizou-se a teoria dos direitos fundamentais de Robert Alexy, com a pondera????o e o sopesamento do princ??pio da imunidade tribut??ria rec??proca com o da livre concorr??ncia, a fim de verificar qual deles deve prevalecer no caso concreto. Por fim, foi apresentada uma proposta de solu????o para o leading case que tem a pretens??o tanto de harmonizar o conflito principiol??gico constatado, como de aprimorar a estrutura????o da regra-matriz do IPTU, particularmente no que tange ?? defini????o de seus crit??rios material, pessoal e quantitativo.
183

Partitions et décompositions de graphes / Partitions and decompositions of graphs

Bensmail, Julien 10 June 2014 (has links)
Cette thèse est dédiée à l’étude de deux familles de problèmes de partition de graphe. Nous considérons tout d’abord le problème de sommet-partitionner un graphe en sous-graphesconnexes. Plus précisément, étant donnés p entiers positifs n1; n2; :::; np dont la somme vautl’ordre d’un graphe G, peut-on partitionner V (G) en p parts V1; V2; :::; Vp de sorte que chaque Vi induise un sous-graphe connexe d’ordre ni ? Nous nous intéressons ensuite à des questions plus fortes. Que peut-on dire si l’on souhaite que G soit partitionnable de cette manière quels que soient p et n1; n2; :::; np ? Si l’on souhaite que des sommets particuliers de G appartiennent à des sous-graphes particuliers de la partition ? Et si l’on souhaite que les sous-graphes induits soient plus que connexes ? Nous considérons toutes ces questions à la fois du point de vue structurel (sous quelles conditions structurelles une partition particulière existe-t-elle nécessairement ?) et algorithmique (est-il difficile de trouver une partition particulière ?).Nous nous intéressons ensuite à la 1-2-3 Conjecture, qui demande si tout graphe G admet une 3-pondération voisin-somme-distinguante de ses arêtes, i.e. une 3-pondération par laquelle chaque sommet de G peut être distingué de ses voisins en comparant uniquement leur somme de poids incidents. Afin d’étudier la 1-2-3 Conjecture, nous introduisons notamment la notionde coloration localement irrégulière d’arêtes, qui est une coloration d’arêtes dont chaque classe de couleur induit un sous-graphe dans lequel les sommets adjacents sont de degrés différents.L’intérêt principal de cette coloration est que, dans certaines situations, une pondération d’arêtes voisin-somme-distinguante peut être déduite d’une coloration d’arêtes localement irrégulière. Nospréoccupations dans ce contexte sont principalement algorithmiques (est-il facile de trouver une pondération d’arêtes voisin-somme-distinguante ou une coloration d’arêtes localement irrégulière utilisant le plus petit nombre possible de poids ou couleurs ?) et structurelles (quel est le plus petit nombre de couleurs d’une coloration d’arêtes localement irrégulière ?). Nous considérons également ces questions dans le contexte des graphes orientés. / This thesis is dedicated to the study of two families of graph partition problems.First, we consider the problem of vertex-partitioning a graph into connected subgraphs.Namely, given p positive integers n1; n2; :::; np summing up to the order of some graph G, canwe partition V (G) into p parts V1; V2; :::; Vp so that each Vi induces a connected subgraph withorder ni? We then consider stronger questions. Namely, what if we want G to be partitionablewhatever are p and n1; n2; :::; np? What if we also want specific vertices of G to belong to somespecific subgraphs induced by the vertex-partition? What if we want the subgraphs induced bythe vertex-partition to be more than connected? We consider all these questions regarding boththe structural (are there structural properties ensuring that a specific vertex-partition necessarilyexists?) and algorithmic (is it hard to deduce a specific vertex-partition?) points of view.Then, we focus on the so-called 1-2-3 Conjecture, which asks whether every graph G admitsa neighbour-sum-distinguishing 3-edge-weighting, i.e. a 3-edge-weighting by which all adjacentvertices of G get distinguished by their sums of incident weights. As a tool to deal with the1-2-3 Conjecture, we notably introduce the notion of locally irregular edge-colouring, which isan edge-colouring in which every colour class induces a subgraph whose adjacent vertices havedistinct degrees. The main point is that, in particular situations, a neighbour-sum-distinguishingedge-weighting of G can be deduced from a locally irregular edge-colouring of it. Our concernsin this context are mostly algorithmic (can we easily find a neighbour-sum-distinguishing edgeweightingor locally irregular edge-colouring using the least number of weights or colours?) andstructural (what is the least number of colours in a locally irregular edge-colouring?). We alsoconsider similar matters in the context of oriented graphs.
184

Proximity-to-Separation Based Energy Function Control Strategy for Power System Stability

Chan, Teck-Wai January 2003 (has links)
The issue of angle instability has been widely discussed in the power engineering literature. Many control techniques have been proposed to provide the complementary synchronizing and damping torques through generators and/or network connected power apparatus such as FACTs, braking resistors and DC links. The synchronizing torque component keeps all generators in synchronism while damping torque reduces oscillations and returns the power system to its pre-fault operating condition. One of the main factors limiting the transfer capacity of the electrical transmission network is the separation of the power system at weak links which can be understood by analogy with a large spring-mass system. However, this weak-links related problem is not dealt with in existing control designs because it is non-trivial during transient period to determine credible weak links in a large power system which may consist of hundreds of strong and weak links. The difficulty of identifying weak links has limited the performance of existing controls when it comes to the synchronization of generators and damping of oscillations. Such circumstances also restrict the operation of power systems close to its transient stability limits. These considerations have led to the primary research question in this thesis, "To what extent can the synchronization of generators and damping of oscillations be maximized to fully extend the transient stability limits of power systems and to improve the transfer capacity of the network?" With the recent advances in power electronics technology, the extension of transfer capacity is becoming more readily achievable. Complementary to the use of power electronics technology to improve transfer capacity, this research develops an improved control strategy by examining the dynamics of the modes of separation associated with the strong and weak links of the reduced transmission network. The theoretical framework of the control strategy is based on Energy Decomposition and Unstable Equilibrium Points. This thesis recognizes that under extreme loadings of the transmission network containing strong and weak links, weak-links are most likely to dictate the transient stability limits of the power system. We conclude that in order to fully extend the transient stability limits of power system while maximizing the value of control resources, it is crucial for the control strategy to aim its control effort at the energy component that is most likely to cause a separation. The improvement in the synchronization amongst generators remains the most important step in the improvement of the transfer capacity of the power system network.
185

Multidimensional Perspectives on Poverty

Pasha, Atika 27 June 2016 (has links)
Gleichzeitig mit der weit verbreiteten Verwendung von traditionellen einkommens- oder konsumbasierten Maßnahmen zur Messung menschlicher Armut und Entwicklung gibt es seit den späten 70er Jahren zunehmendes Interesse an der Ökonomie des Glücks. Ebenso gibt es einen breiten Literaturbereich, der Indizes definiert und diskutiert hat, die „functionings" auf der Grundlage des „Capabilities Approach“ von Sen (1985) auf sich vereinen, welche auf einer Vielzahl von ideologischen Urteilen und Zielen zur Bestimmung des objektiven Wohlbefindens (1984), S. 187) beruhen. Beide Ansätze sind ähnlich in ihrer Prämisse, dass Einkommen oft eine unzureichende Determinante des Wohlbefindens ist – ein latenter Begriff, dass besser mit anderen, breiteren Definitionen- subjektiv oder objektiviert- erfasst wird. Beide Konzepte des Wohlbefindens wurden im Hinblick auf ihr Verhältnis zum Einkommen untersucht, und es wurde ein klarer Unterschied zwischen Einkommen und diesen beiden Maßnahmen festgestellt. Angesichts der relativen Neuheit und Komplexität beider Ansätze sind sie jedoch bislang selten in wissenschaftlichen Arbeiten zusammengebracht worden. Den dritten Aufsatz in dieser Arbeit ist ein Versuch, diese beiden Ansätze zu kombinieren und damit diese Lücke in der Literatur zu erfüllen. Subjektives Wohlbefinden wird mit verfügbaren Daten, die Zufriedenheit messen, festelegt, während das objektive Wohlbefinden durch einen Multidimensional Poverty Index (MPI) operationalisiert wird (Alkire & Santos, 2010). Der MPI ist einer der neuesten Versuche zur Messung des menschlichen Wohlbefindens im Rahmen des Capabilities Approach. Die Entwicklungspolitik erkennt ebenfalls graduell diese Maße als eine genauere Beschreibung des Wohlbefindens an, oder betrachtet diese zumindest als eine sinnvolle Ergänzung zu metrisch-monetären Maßen. Angesichts der vielen nationalen und internationalen Programme, die eine umfassende Verbesserung des menschlichen Wohlbefindens zum Ziel haben, gibt es erstaunlich wenige Arbeiten, die dazu beitragen können, die Auswirkungen eines bestimmten Programms auf das allgemeine Wohlbefinden und nicht nur auf eine bestimmte Dimension zu quantifizieren und zu bewerten. Der zweite Aufsatz in dieser Arbeit beschäftigt sich kritisch mit diesem Ansatz und betrachtet dabei den besonderen Fall Südafrikas. Aufgrund der steigenden Beliebtheit der mehrdimensionalen Armutsmaße besteht ein zunehmender Bedarf an einer Überprüfung ihrer grundlegenden Eigenschaft, ebendies zu erreichen. Eine wachsende Zahl von Forschern hat sich mit den Problemen beschäftigt, die ein zusammengesetztes Maß wie der MPI mit sich bringen kann und dessen Fähigkeit zur Messung multidimensionalen Wohlbefindens beeinträchtigen kann. Ein bestimmter Aspekt ist hierbei die Gewichtung der einzelnen Dimensionen und Indikatoren, um Armut über verschiedene Regionen hinweg zu definieren. Diese Dissertation schafft in Aufsatz eins eine Brücke zwischen den statistischen Methoden und den optimalen Gewichtungsschemata, die speziell zur Messung des multidimensionalen Wohlbefindens in verschiedenen Ländern genutzt werden können.
186

O comportamento do investidor brasileiro na alocação de ativos

Iglesias, Martin Casals 15 February 2006 (has links)
Made available in DSpace on 2010-04-20T21:00:18Z (GMT). No. of bitstreams: 3 martincasalsturma2003.pdf.jpg: 11517 bytes, checksum: 930c75c74ff8269d877983110854646d (MD5) martincasalsturma2003.pdf: 975293 bytes, checksum: f41cfd3a5f3e659d07e2861acf4e23d4 (MD5) martincasalsturma2003.pdf.txt: 107784 bytes, checksum: e96ad0fb809a12f13ba7d3f08e24c1ee (MD5) Previous issue date: 2006-02-15T00:00:00Z / O objetivo deste trabalho é analisar a alocação de investimentos no mercado acionário brasileiro, utilizando a teoria do prospecto de Tversky e Kahneman (1979) e o conceito de Aversão a Perdas Míope (Myopic Loss Aversion) proposto por Benartzi e Thaler (1995). Foram levantados através de experimento de laboratório os parâmetros da função de valor e da função de ponderação de probabilidades da teoria do prospecto e foi verificada a alocação de investimentos entre ações e renda fixa que maximizam a utilidade. Chegamos à conclusão que o total de recursos atualmente direcionados ao mercado de ações no Brasil, que é de aproximadamente 2,7% para pessoas físicas e de 6,0% para pessoas jurídicas, é compatível com a teoria do prospecto. / The objective of this study is to analyze the investment allocation in the Brazilian stock market, using Tversky and Kahneman’s prospect theory (1979) and the concept of myopic loss aversion proposed by Benartzi and Thaler (1995). We run a laboratory experiment to obtain the parameters of the value function and the probability weighting function of the prospect theory and identify the allocation that maximizes utility in the Brazilian Market We conclude that the actual allocation of investment in the stock market, of around 2.7% for individuals and around 6% for all the segments, is in accordance with the prospect theory.
187

Prédiction de suites individuelles et cadre statistique classique : étude de quelques liens autour de la régression parcimonieuse et des techniques d'agrégation / Prediction of individual sequences and prediction in the statistical framework : some links around sparse regression and aggregation techniques

Gerchinovitz, Sébastien 12 December 2011 (has links)
Cette thèse s'inscrit dans le domaine de l'apprentissage statistique. Le cadre principal est celui de la prévision de suites déterministes arbitraires (ou suites individuelles), qui recouvre des problèmes d'apprentissage séquentiel où l'on ne peut ou ne veut pas faire d'hypothèses de stochasticité sur la suite des données à prévoir. Cela conduit à des méthodes très robustes. Dans ces travaux, on étudie quelques liens étroits entre la théorie de la prévision de suites individuelles et le cadre statistique classique, notamment le modèle de régression avec design aléatoire ou fixe, où les données sont modélisées de façon stochastique. Les apports entre ces deux cadres sont mutuels : certaines méthodes statistiques peuvent être adaptées au cadre séquentiel pour bénéficier de garanties déterministes ; réciproquement, des techniques de suites individuelles permettent de calibrer automatiquement des méthodes statistiques pour obtenir des bornes adaptatives en la variance du bruit. On étudie de tels liens sur plusieurs problèmes voisins : la régression linéaire séquentielle parcimonieuse en grande dimension (avec application au cadre stochastique), la régression linéaire séquentielle sur des boules L1, et l'agrégation de modèles non linéaires dans un cadre de sélection de modèles (régression avec design fixe). Enfin, des techniques stochastiques sont utilisées et développées pour déterminer les vitesses minimax de divers critères de performance séquentielle (regrets interne et swap notamment) en environnement déterministe ou stochastique. / The topics addressed in this thesis lie in statistical machine learning. Our main framework is the prediction of arbitrary deterministic sequences (or individual sequences). It includes online learning tasks for which we cannot make any stochasticity assumption on the data to be predicted, which requires robust methods. In this work, we analyze several connections between the theory of individual sequences and the classical statistical setting, e.g., the regression model with fixed or random design, where stochastic assumptions are made. These two frameworks benefit from one another: some statistical methods can be adapted to the online learning setting to satisfy deterministic performance guarantees. Conversely, some individual-sequence techniques are useful to tune the parameters of a statistical method and to get risk bounds that are adaptive to the unknown variance. We study such connections for several connected problems: high-dimensional online linear regression under a sparsity scenario (with an application to the stochastic setting), online linear regression on L1-balls, and aggregation of nonlinear models in a model selection framework (regression on a fixed design). We also use and develop stochastic techniques to compute the minimax rates of game-theoretic online measures of performance (e.g., internal and swap regrets) in a deterministic or stochastic environment.
188

Hlukoměr pro embedded systémy / Sound level meter for embedded systems

Stejskal, Tomáš January 2015 (has links)
The aim of this work is the design and implementation of a sound level meter for emdedded systems. It is designed sound level meter sensor. This sensor includes a microphone, microphone preamplifier and ADC. This sensor is connected to a development kit STM32F4 Discovery, where sound is processed. It is processed filtration, time weighting, calculation of sound leve and loudness weighting. The sound level is then sent via the serial communication USART. This thesis includes a theoretical analysis of noise and its human perceptions. It also describes the development platform used.
189

Vyhodnocování dopravního hluku a jeho modelování / Evaluation and modelling of Traffic Noise

Černoch, Adam January 2014 (has links)
The task of the master's thesis is introduction with the problems of traffic noise, focusing on noise from road traffic. There is a description what is the noise, how it is formed, its resources and what are the methods of measuring. The following are the various noise reduction measures such as noise barriers and low noise pavements. The main attention is devoted to the noise generated at the tire / road that is reduced by these pavements. The practical part describes the implemented measurements on individual sections at various locations in our country. The measurement was carried by slightly modified method CPX with reference tire directly at the vehicle. The main aim was to evaluate the measurement data, make comparison of different low-noise surfaces with each other and with the commonly used surfaces. Then quantification of the rate reduction of the noise emission for a given section and verification of input data for noise modeling. In conclusion, the obtained results are summarized and based on them were confirmed very good acoustic properties with the recommendation to continue with measurements in the future.
190

Inference v Bayesovských sítích / Inference in Bayesian Networks

Šimeček, Josef January 2013 (has links)
This master's thesis deals with demonstration of various approaches to probabilistic inference in Bayesian networks. Basics of probability theory, introduction to Bayesian networks, methods for Bayesian inference and applications of Bayesian networks are described in theoretical part. Inference techniques are explained and complemented by their algorithm. Techniques are also illustrated on example. Practical part contains implementation description, experiments with demonstration applications and conclusion of the results.

Page generated in 0.0741 seconds