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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.
711

Opérateurs d’inf-convolution et inégalités de transport sur les graphes / Infimum-convolution operators and transport inequalities on discrete spaces

Shu, Yan 07 July 2016 (has links)
Dans cette thèse, nous nous intéressons à différents opérateurs d'inf-convolutions et à leurs applications à une classe d'inégalités de transport générales, plus spécifiquement sur les graphes. Notre objet de recherche s'inscrit donc dans les théories du transport de mesure et de l'analyse fonctionnelle. En introduisant une notion de gradient adapté au cadre discret (et plus généralement à tout espace métrique dont les boules sont compactes), nous prouvons que certains opérateurs d'inf-convolution sont solutions d'une inéquation d'Hamilton Jacobi sur les graphes. Ce résultat nous permet d'étendre au cadre discret un théorème classique de Bobkov, Gentil et Ledoux. Plus précisément nous montrons que des inégalités de transport faible (adaptées au cadre discret) sont équivalentes, sur un graphe, à l'hypercontractivité des opérateurs d'inf-convolutions. On en déduit plusieurs résultats concernant différentes inégalités fonctionnelles, dont celle de Sobolev logarithmique et de transport faible. Nous étudions par ailleurs les propriétés générales de différents opérateurs d'inf-convolutions, incluant le précédent, mais aussi un opérateur relié à un modèle issu de la physique (et au phénomène de grande déviation), toujours sur les graphes (dérivabilités, convexité, points extremum etc.). Dans un deuxième temps, nous nous intéressons aux liens entre différentes notions de courbure de Ricci sur les graphes -- proposées récemment par plusieurs auteurs -- et les inégalités fonctionnelles de type transport-entropie, ou transport-information associées à une chaîne de Markov. Nous obtenons également une borne supérieure sur le diamètre d'un graphe dont la courbure, en un certain sens, est minorée, un résultat à la Bonnet-Myers. Enfin, en nous restreignant au cas de la dimension 1, sur la droite réelle, nous obtenons une caractérisation d'une inégalité de transport faible et de l'inégalité de Sobolev logarithmique restreinte aux fonctions convexes. Ces résultats utilisent des propriétés géométriques liés à l'ordre convexe. / In this thesis, we interest in different inf-convolution operators and their applications to a class of general transportation inequalities, more specifically in the graphs. Therefore, our research topic fits in the theories of transportation and functional analysis. By introducing a gradient notion adapting to a discrete space (more generally to all space in which all closed balls are compact), we prove that some inf-convolution operators are solutions of a Hamilton-Jacobi's inequation. This result allows us to extend a classical theorem from Bobkov, Gentil and Ledoux. More precisely, we prove that, in a graph, some weak transport inequalities are equivalent to the hypercontractivity of inf-convolution operators. Thanks to this result, we deduce some properties concerning different functional inequalities, including Log-Sobolev inequalities and weak-transport inequalities. Besides, we study some general properties (differentiability, convexity, extreme points etc.) of different inf-convolution operators, including the one before, but also an operator related to a physical model (and to a large deviation phenomenon). We stay always in a graph. Secondly, we interest in connections between different notions of discrete Ricci curvature on the graphs which are proposed by several authors in the recent years, and functional inequalities of type transport-entropy, or transport-information related to a Markov chain. We also obtain an extension of Bonnet-Myers' result: an upper bound on the diameter of a graph of which the curvature is floored in some ways. Finally, restricting in the real line, we obtains a characterisation of a weak transport inequality and a log-Sobolev inequality restricted to convex functions. These results are from the geometrical properties related to the convex ordering.
712

Regularized Jackknife estimation with many instruments

Doukali, Mohamed 10 1900 (has links)
No description available.
713

Justiciability of regressive measures of social rights. Some reflections about their judicial protection in Latin America / Justiciabilidad de las medidas regresivas de los derechos sociales. Algunas reflexiones acerca de su protección en América Latina

Torres Zuñiga, Natalia 10 April 2018 (has links)
This  article  has  as  aim  to  reflect  about  the  protection  of economic, social and cultural rights before the regressive measures adopted by governments in Latin America, as well as of the different levels of jurisdictional tutelage that those receive. The document develops the concept of a regressive measure and the scope of the non-regression principle, furthermore, it shows the experience of the Constitutional Courts from Peru and Colombia and the organs of the Interamerican System of Human Rights regarding the protection of social rights. / El presente artículo tiene por propósito plantear una reflexión sobre la protección jurisdiccional que reciben los derechos sociales frente a la adopción de medidas regresivas en Latinoamérica por parte de los Estados, así como de los diversos grados de tutela jurisdiccional que aquellos reciben. El artículo desarrolla la noción de regresividad y los alcances del principio de prohibición de regresividad, así como la experiencia  de las Cortes Constitucionales de Perú y Colombia y de los órganos el Sistema Interamericano de Derechos Humanos en torno a la protección de los derechos sociales.
714

Efeitos de choques globais na economia brasileira: uma análise a partir do GVAR

Zanetta Neto, Ary Cera 05 August 2014 (has links)
Submitted by Ary Cera Zanetta Neto Zanetta (ary.zanetta@brasil-capital.com) on 2014-08-19T19:21:54Z No. of bitstreams: 1 Efeitos de Choques Globais na Economia Brasileira_ Uma Análise a Partir do GVAR.pdf: 1085836 bytes, checksum: 25e953aa352fed09b5b828362226aab9 (MD5) / Rejected by JOANA MARTORINI (joana.martorini@fgv.br), reason: A ficha catalográfica não está valida, por gentileza aguardar o envio da ficha correta pala biblioteca digital. on 2014-08-19T19:29:14Z (GMT) / Submitted by Ary Cera Zanetta Neto Zanetta (ary.zanetta@brasil-capital.com) on 2014-08-19T20:33:33Z No. of bitstreams: 1 Efeitos de Choques Globais na Economia Brasileira_ Uma Análise a Partir do GVAR.pdf: 1085836 bytes, checksum: 25e953aa352fed09b5b828362226aab9 (MD5) / Approved for entry into archive by JOANA MARTORINI (joana.martorini@fgv.br) on 2014-08-20T16:30:59Z (GMT) No. of bitstreams: 1 Efeitos de Choques Globais na Economia Brasileira_ Uma Análise a Partir do GVAR.pdf: 1085836 bytes, checksum: 25e953aa352fed09b5b828362226aab9 (MD5) / Made available in DSpace on 2014-08-20T19:02:31Z (GMT). No. of bitstreams: 1 Efeitos de Choques Globais na Economia Brasileira_ Uma Análise a Partir do GVAR.pdf: 1085836 bytes, checksum: 25e953aa352fed09b5b828362226aab9 (MD5) Previous issue date: 2014-08-05 / O objetivo deste estudo é avaliar a propagação de choques econômicos de alguns países sobre o crescimento econômico brasileiro, com principal destaque para China, Estados Unidos da América (EUA) e Argentina, que são os principais parceiros comerciais do Brasil. O aumento do comércio com a China tornou o Brasil muito mais vulnerável a choques no PIB chinês e menos vulnerável, do que no passado recente, a choques no PIB americano, enquanto que a influência da Argentina manteve-se estável. Foi aplicada a metodologia Vetor Autorregressivo Global (Global Var – GVAR), introduzida por Pesaran, Schuermann e Weiner (2004), Garratt, Lee, Pesaran e Shin (2006) e Dées, Di Mauro, Pesaran e Smith (2007), para analisar os canais de comércio e a transmissão de choques entre o resto do mundo e o Brasil. Usando dados trimestrais a partir de 1990 até o final de 2013, foi possível constatar que o aumento da relevância da economia Chinesa na balança comercial Brasileira exerce pressão sobre o crescimento econômico do Brasil. Em suma, a China tornou-se mais relevante para o crescimento econômico do Brasil do que os EUA e a Argentina. / The objective of this study is to evaluate the impact of variations in the Gross Domestic Product (GDP) of countries and economic blocks over Brazilian economic growth, with emphasis on China, United States of America (USA) and Argentina, which are the main commercial partners of Brazil. The increase in trading with China has made Brazil more vulnerable to shocks in Chinese GDP and less vulnerable, than in the recent past, to shocks in American GDP, and stability in the case of Argentina. It has been applied the methodology Global Vector Autorregressive (Global Var – GVAR), introduced, explained and expanded by Pesaran, Schuermann and Weiner (2004), Garratt, Lee, Pesaran and Shin (2006) and Dées, Di Mauro, Pesaran and Smith (2007) to analyze the trading channels and the transmission of shocks between the rest of the world and Brazil (specially with China, USA and Argentina). Using a sample from the first quarter of 1990 to the third quarter of 2013 it is possible to see that the increase of relevance of the Chinese economy on the Brazil trade balance increased the relevance of the Chinese economy over the Brazilian economy. Therefore, the conclusions of this work indicate a considerable vulnerability of the Brazilian economy to the Chinese economic cycle and, in a lower degree than in the past, to the American and Argentinian economies.
715

Asymptotic efficiency in an instrumental variable model

Chaves, Leonardo Salim Saker 28 April 2015 (has links)
Submitted by Leonardo Salim Saker Chaves (lsalimsaker@gmail.com) on 2015-07-24T19:51:22Z No. of bitstreams: 1 Dissertacao_LeonardoSalim_BMHS.pdf: 661288 bytes, checksum: a89da060d1378be5cf51ff1edc18cfc6 (MD5) / Approved for entry into archive by BRUNA BARROS (bruna.barros@fgv.br) on 2015-07-27T14:42:35Z (GMT) No. of bitstreams: 1 Dissertacao_LeonardoSalim_BMHS.pdf: 661288 bytes, checksum: a89da060d1378be5cf51ff1edc18cfc6 (MD5) / Approved for entry into archive by Maria Almeida (maria.socorro@fgv.br) on 2015-07-30T19:33:12Z (GMT) No. of bitstreams: 1 Dissertacao_LeonardoSalim_BMHS.pdf: 661288 bytes, checksum: a89da060d1378be5cf51ff1edc18cfc6 (MD5) / Made available in DSpace on 2015-07-30T19:33:33Z (GMT). No. of bitstreams: 1 Dissertacao_LeonardoSalim_BMHS.pdf: 661288 bytes, checksum: a89da060d1378be5cf51ff1edc18cfc6 (MD5) Previous issue date: 2015-04-28 / This work studies the hypothesis testing based on generalized method of moments (GMM) estimation given by instruments condition. The importance for the development of Economics lies on the fact that when identi cation is weak, the standard test can be misleading. Therefore, it is made a review of proposed tests to overcome this problem and also present two useful frameworks of study; from Moreira (2002), Moreira and Moreira (2013) and Kleibergen (2005). So, this work conciliate the previous frameworks a way to write the score proposed initially in Kleibergen (2005) using Moreira and Moreira (2013) statistics and presents the optimal score test based on asymptotic theory from Newey and McFadden (1984). Moreover, the study shows the equivalence between the GMM and maximum likelihood estimation to deal with the weak instruments problem. / Esta dissertação se propõe ao estudo de inferência usando estimação por método generalizado dos momentos (GMM) baseado no uso de instrumentos. A motivação para o estudo está no fato de que sob identificação fraca dos parâmetros, a inferência tradicional pode levar a resultados enganosos. Dessa forma, é feita uma revisão dos mais usuais testes para superar tal problema e uma apresentação dos arcabouços propostos por Moreira (2002) e Moreira & Moreira (2013), e Kleibergen (2005). Com isso, o trabalho concilia as estatísticas utilizadas por eles para realizar inferência e reescreve o teste score proposto em Kleibergen (2005) utilizando as estatísticas de Moreira & Moreira (2013), e é obtido usando a teoria assintótica em Newey & McFadden (1984) a estatística do teste score ótimo. Além disso, mostra-se a equivalência entre a abordagem por GMM e a que usa sistema de equações e verossimilhança para abordar o problema de identificação fraca.
716

Corporate governance: a critical analysis of the effectiveness of boards of directors in public entities in Zimbabwe

Moyo, Nomusa Jane 10 1900 (has links)
The degree to which a country’s public entities observe basic principles of good corporate governance is an increasingly important factor for attracting investment capital, maintaining economic stability and encouraging growth. Zimbabwe is faced with the challenge of restructuring for greater efficiency and creating an investment-friendly environment, therefore practicing good corporate governance in public entities is crucial for success and economic growth. As business entities, public entities need to be managed effectively by a competent board, which is able to construct and implement strategies that are in the best interests of the entity and all stakeholders. This study focuses on the corporate governance initiatives, laws and regulations aimed at enhancing the effectiveness of boards of public entities in Zimbabwe. The key question addressed is whether or not the corporate governance initiatives and legal and regulatory reforms in Zimbabwe are sufficient to enable boards of public entities to effectively discharge their duties and meet internationally accepted corporate governance standards. A comparative analysis of Zimbabwe’s public entities corporate governance framework to that of South Africa (a developing country like Zimbabwe) and Australia (a developed country with similar common law heritage) is also conducted. Recommendations are made on how best to enhance the effectiveness of boards of public entities in order to promote good corporate governance practices in Zimbabwean public entities. The research established that the existing corporate governance framework has not been effective in improving the effectiveness of Zimbabwe public entity boards due to lack of commitment and consistency, political interference, weak enforcement mechanisms, corruption and general disregard for the rule of law. The research found that South Africa and Australia have performed better than Zimbabwe in terms of creating conducive environments for boards of public entities to effectively discharge their duties. To improve the effectiveness of public entity boards, it was found that boards should be properly empowered, government intervention should be minimised, board appointment processes should be transparent and merit-based, boards should be properly composed, board remuneration should be fair and performance related, the performance of the board should be regularly evaluated and effective enforcement mechanisms should be put in place. / Mercantile Law / LL. D.
717

Variants of P-frames and associated rings

Nsayi, Jissy Nsonde 12 1900 (has links)
We study variants of P-frames and associated rings, which can be viewed as natural generalizations of the classical variants of P-spaces and associated rings. To be more precise, we de ne quasi m-rings to be those rings in which every prime d-ideal is either maximal or minimal. For a completely regular frame L, if the ring RL of real-valued continuous functions of L is a quasi m-ring, we say L is a quasi cozero complemented frame. These frames are less restricted than the cozero complemented frames. Using these frames we study some properties of what are called quasi m-spaces, and observe that the property of being a quasi m-space is inherited by cozero subspaces, dense z- embedded subspaces, and regular-closed subspaces among normal quasi m-space. M. Henriksen, J. Mart nez and R. G. Woods have de ned a Tychono space X to be a quasi P-space in case every prime z-ideal of C(X) is either minimal or maximal. We call a point I of L a quasi P-point if every prime z-ideal of RL contained in the maximal ideal associated with I is either maximal or minimal. If all points of L are quasi P-points, we say L is a quasi P-frame. This is a conservative de nition in the sense that X is a quasi P-space if and only if the frame OX is a quasi P-frame. We characterize these frames in terms of cozero elements, and, among cozero complemented frames, give a su cient condition for a frame to be a quasi P-frame. A Tychono space X is called a weak almost P-space if for every two zero-sets E and F of X with IntE IntF, there is a nowhere dense zero-set H of X such that E F [H. We present the pointfree version of weakly almost P-spaces. We de ne weakly regular rings by a condition characterizing the rings C(X) for weak almost P-spaces X. We show that a reduced f-ring is weakly regular if and only if every prime z-ideal in it which contains only zero-divisors is a d-ideal. We characterize the frames L for which the ring RL of real-valued continuous functions on L is weakly regular. We introduce the notions of boundary frames and boundary rings, and use them to give another ring-theoretic characterization of boundary spaces. We show that X is a boundary space if and only if C(X) is a boundary ring. A Tychono space whose Stone- Cech compacti cation is a nite union of closed subspaces each of which is an F-space is said to be nitely an F-space. Among normal spaces, S. Larson gave a characterization of these spaces in terms of properties of function rings C(X). By extending this notion to frames, we show that the normality restriction can actually be dropped, even in spaces, and thus we sharpen Larson's result. / Mathematics / D. Phil. (Mathematics)
718

Techniques d'acquisition à haute sensibilité des signaux GNSS / High-sensitivity adaptive GNSS acquisition schemes

Ferreira Esteves, Paulo Alexandre 27 May 2014 (has links)
Les systèmes de navigation par satellite (GNSS) font partie de notre quotidien. On peut présentement les trouver dans un ensemble d’applications. Avec les nouveaux besoins, des nouveaux enjeux sont aussi apparus : le traitement du signal dans les environnements urbains est extrêmement complexe. Dans cette thèse, le traitement des signaux GNSS à faible puissance est abordé, en particulier dans la première phase du traitement, nommé acquisition de signal. Le premier axe de rechercheporte sur l’analyse et la compensation de l’effet Doppler dans l’acquisition. Le décalage Doppler perçu par l’utilisateur est un des paramètres principaux pour la configuration du module d’acquisition. Dans cette étude, des solutions sont proposées pour trouver le meilleur compromis sensibilité-complexité propre à l’acquisition. En deuxième axe, la caractérisation des détecteurs différentiels est abordée, en particulier la quantification de sa sensibilité. Pour l’acquisition des signaux faibles, après une première phase d’intégration cohérente, il faut passer par une intégration «postcohérente» (noncohérente ou différentielle.) L’analyse exécutée ici permet de meilleur identifier le meilleur choix entre les deux possibilités. Le troisième axe de recherche est consacré à la méthode de Détection Collective (CD), une innovation qui fait l’acquisition simultanée de tous les signaux visible par le récepteur. Plusieurs analyses sont réalisées incluant l’amélioration de la procédure de recherche de la CD, et l’hybridisation avec l’acquisition standard. Enfin on effectuel’analyse de la CD dans un contexte multi-constellation, en utilisant simultanément des vrais signaux GPS et Galileo. / Satellite navigation (GNSS) is a constant in our days. The number of applications that depend on it is already remarkable and is constantly increasing. With new applications, new challenges have also risen: much of the new demand for signals comes from urban areas where GNSS signal processing is highly complex. In this thesis the issue of weak GNSS signal processing is addressed, in particular at the first phase of the receiver processing, known as signal acquisition. The first axe of research pursued deals with the analysis and compensation of the Doppler effect in acquisition. The Doppler shift that is experienced by a user is one of the main design drivers for the acquisitionmodule and solutions are proposed to improve the sensitivity-complexity trade-off typical of the acquisition process. The second axe of research deals with the characterization of differential GNSS detectors. After a first step of coherent integration, transition to post coherent (noncoherent or differential) integration is required for acquiring weak signals. The quantification of the sensitivity of differential detectors was not found in literature and is the objective of this part of the research. Finally, the third axe of research is devoted to multi-constellation Collective Detection (CD). CD is an innovative approach for the simultaneous processing of all signals in view. Severalissues related to CD are addressed, including the improvement of the CD search process and the hybridization with standard acquisition. Finally, the application of this methodology in the context of a multi-constellation receiver is also addressed, by processing simultaneously real GPS and Galileo signals.
719

Enslaved under the elements of the cosmos

Clark, Ernest P. January 2018 (has links)
When Paul writes ‘we too were enslaved under the elements of the world', he means that the elements that compose the cosmos also compose and compromise the flesh and enslave human persons through their bodies (Gal 4.3). This thesis demonstrates that early Jews used the phrase στοιχεῖα τοῦ κόσμου to refer to the material elements – earth, water, air, and fire – and not to elemental spirits or elementary principles. Greek medical tradition understood the material elements to mediate the stimuli (παθήματα) and desires of the body which enslave the soul, and it prescribed a variety of regimens (including νόμος) as παιδαγωγοί to guide a person to wholeness. In his philosophy according to the cosmic elements, Philo promotes the law of Moses – including circumcision and the calendar – as the effective way to be ‘redeemed from slavery' to the flesh, to attain righteousness, and to live in harmony with the cosmos. Paul's epistle to the Galatians opposes this sort of ‘redemptive nomism'. Paul accepts that weak στοιχεῖα compose the weak σάρξ and that they mediate sinful stimuli and desires that lead to the actions of the flesh. However, he denies that the law can make people alive or righteous. Instead, Paul prescribes crucifixion with Christ and new life with the Spirit as the final cure for sin's infection of the flesh made of weak στοιχεῖα. Through faith, Christ will be formed in believers as the Spirit guides them away from the desires of the flesh and produces his fruit in their lives.
720

Áxions, májorons e neutrinos em extensões do modelo padrão /

Sánchez Vega, Bruce Lehmann. January 2011 (has links)
Orientador: Juan Carlos Montero Garcia / Banca: Alex Gomes Dias / Banca: João dos Anjos / Banca: Marcelo Moraes Guzzo / Banca: Rogério Rosenfeld / Resumo: Nesta tese, partículas tais como áxions, Májorons e neutrinos são consideradas em duas extensões eletrofracas do modelo padrão da física de partículas. Especificamente, os modelos considerados estão baseados nas simetrias de gauge SU(3)L ⊗ U(1)X eSU(2)L ⊗U(1)Y⊗U(1)B−L. Primeiramente, no contexto do modelo 3-3-1 com um sector escalar mínimo é realizado um estudo detalhado referente à implementção da simetria de Peccei-Quinn (PQ) para resolver o problema CP forte. Para a versão original do modelo, que possui apenas dois tripletos escalares, é mostrado que a Lagrangiana total é invariante sobre uma simetria PQ. No entanto, o áxion não é produzido porque um sub-grupo permanece sem quebrar. Embora, neste caso, o problema CP forte possa ser resolvido, a solução é amplamente desfavorecida porque três quarks não têm massa em todas as ordens da teoria de perturbação. A adição de um terceiro tripleto escalar resolve o problema dos quarks sem massa, mas o áxion que aparece é visível. Para fazer o modelo realístico teremos que modificá-lo. É mostrado que a adição de um singleto escalar junto com uma simetria de gauge discreta ZN é capaz de levar a cabo esta tarefa e proteger o áxion de efeitos da gravidade quântica. Para ter segurançaa que a simetria de gauge discreta que protege o áxion é livre de anomalias, é usada uma versão discreta do mecanismo de Green-Schwarz. A seguir, é considerado um modelo eletrofraco baseado na simetria de gauge SU(2)L ⊗U(1)Y⊗U(1)B−L, no qual temos neutrinos de mão direita com números quânticos exóticos e diferentes. Devido a esta particular caraterística, é possível termos de massa e de Yukawa para os neutrinos, com campos escalares que podem adquirir valores esperados do vácuo (VEVs) pertencendo a escalas de energia... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In this doctoral thesis axions, Majorons and neutrinos are considered into different electro weak extensions of the standar dmodel of the particle physics. Specifically, the two models considered are based on theSU(3)L ⊗U(1)X andSU(2)L⊗U(1)Y⊗ U(1)B−Lgaugesymmetries. Firstly, in the framework of a 3-3-1 model with a minimal scalar sector a detailed study concerning the implementation of the PQ symmetry in order to solve the strong CP problem is made. For the original version of the model, with only two scalar triplets, it is shown that the entire Lagrangian is invariant under a PQ-like symmetry but no axion is produced since aU(1) subgroup remains unbroken. Although in this case the strong CP problem can still be solved, the solution is largely disfavored since three quark states are left massless to all orders in perturbation theory. The addition of a third scalar triplet removes the massless quark states but the resulting axion is visible. In order to become realistic the model must be extended to account for massive quarks and invisible axion. It is shown that the addition of a scalar singlet together with aZN discrete gauge symmetry can successfully accomplish these tasks and protect the axion field against quantum gravitational effects. To make sure that the protecting discrete gauge symmetry is anomaly free, a discrete version of th eGreen-Schwarz mechanism is used. Secondly, an electroweak model based on the gauge symmetrySU(2)L ⊗U(1)Y⊗ U(1)B−L which has right-handed neutrinos with different quantum numbers is considered. Because of this particular feature it is possible to write Yukawa terms, and neutrino mass terms, with scalar fields that can develop VEVs belonging to different energy scales. A detailed study of the scalar and the Yukawa neutrino sectors is made to show that this model is compatible with... (Complete abstract click electronic access below) / Doutor

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