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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.
71

Convergence of Conditional Expectation Operators and the Compact Range Property

Dawson, C. Bryan (Charles Bryan) 08 1900 (has links)
The interplay between generalizations of Riezs' famous representation theorem and Radon-Nikodým type theorems has a long history. This paper will explore certain aspects of the theory of bounded linear operators on continuous function spaces, Radon-Nikodým type properties, and their connections.
72

Architecture des services de communication dans un contexte de convergence / Towards a converged environment for communication services

Bertin, Emmanuel 11 December 2009 (has links)
Les services de communication de nouvelle génération doivent pouvoir coopérer pour répondre à des besoins spécifiques tout en gardant leur autonomie. Ceci nécessite de maîtriser leurs architectures et de partager ces architectures au sein de l'entreprise. Des cadres architecturaux communs sont alors indispensables. Après avoir fait le point des travaux sur ce sujet dans les domaines télécoms, web et IT, et après avoir discuté des enjeux de la convergence des services télécoms, nous introduisons ici quatre angles de vue (métier, fonctionnel, technique et applicatif), ainsi qu'une méthodologie pour construire des vues de référence partagées au sein d'une entreprise et des vues d'architecture propres à chaque service. Nous illustrons cette démarche à l'aide d'exemples et montrons ses applications pour construire des offres de service, pour rationnaliser les services existants et pour réaliser une convergence entre différents services. / Next-generation communication services should be able to cooperate in order to meet specific needs, while keeping their autonomy. This implies to master their architectures and to share these architectures within the enterprise. Architectural frameworks are therefore essential. After a review of the state of the art in the telecom, web and IT fields, and after having discussed the stakes of the telecom service convergence, we introduce here four viewpoints (business, functional, technical and applicative), as well as a methodology to build reference views that will be shared across the enterprise, and architectural views that are dedicated to each service. We illustrate this approach through case studies and we point out its applications to build service offers, to rationalize existing services and to realize a convergence between various services.
73

Lattice-valued Convergence: Quotient Maps

Boustique, Hatim 01 January 2008 (has links)
The introduction of fuzzy sets by Zadeh has created new research directions in many fields of mathematics. Fuzzy set theory was originally restricted to the lattice , but the thrust of more recent research has pertained to general lattices. The present work is primarily focused on the theory of lattice-valued convergence spaces; the category of lattice-valued convergence spaces has been shown to possess the following desirable categorical properties: topological, cartesian-closed, and extensional. Properties of quotient maps between objects in this category are investigated in this work; in particular, one of our principal results shows that quotient maps are productive under arbitrary products. A category of lattice-valued interior operators is defined and studied as well. Axioms are given in order for this category to be isomorphic to the category whose objects consist of all the stratified, lattice-valued, pretopological convergence spaces. Adding a lattice-valued convergence structure to a group leads to the creation of a new category whose objects are called lattice-valued convergence groups, and whose morphisms are all the continuous homomorphisms between objects. The latter category is studied and results related to separation properties are obtained. For the special lattice , continuous actions of a convergence semigroup on convergence spaces are investigated; in particular, invariance properties of actions as well as properties of a generalized quotient space are presented.
74

Near Point of Convergence : A Comparison of Four Different Target types

Berglund Pilgrim, Caroline January 2010 (has links)
<p><strong>Purpose:</strong> The purpose of this study was to determine if there were any differences between four different target types when measuring the near point of convergence in adults.</p><p><strong>Methods and Material:</strong> The near point of convergence was measured in 35 subjects with a visual acuity of at least 1.0 (6/6) in each eye and without any strabismus. The targets used were: the tip of a pen, an accommodative target, the RAF line target and a penlight viewed through red-green filters. Both break and recovery points were assessed for the different techniques. Each target was used twice in consecutive order. The line target from RAF ruler was copied on to a small plastic ruler in order to be able to use the same ruler for measuring the results. All subjects were fitted with their best correction in the trial frame after a complete refraction. The measurements were taken to the nearest 0.25cm.</p><p><strong>Results:</strong> There was no difference found between NPC break values for the different target types in the control group. The NPC values were found to be 5.0/7.4 in the control group and 10.8/18.2 in the anomalous group. The accommodative target was found to give more remote values (11.5cm) than expected in comparison to the other targets in the anomalous group.</p><p><strong>Conclusion:</strong> In patients with normal NPC, the measurements can be taken with line target or Acc. target. Patients with receded NPC values should be evaluated with penlight and red-green glasses or at least twice with the tip of a pen. </p>
75

Analyse de la convergence de l'algorithme FastICA : échantillon de taille finie et infinie / Convergence analysis of the FastICA algorithm : finite and infinite sample size

Wei, Tianwen 10 June 2013 (has links)
L'algorithme FastICA est l'un des algorithmes les plus populaires dans le domaine de l'analyse en composantes indépendantes (ICA). Il existe deux versions de FastICA: Celle qui correspond au cas où l'échantillon est de taille infinie, et celle qui traite de la situation concrète, où seul un échantillon de taille finie est disponible. Dans cette thèse, nous avons fait une étude détaillée des vitesses de convergence de l'algorithme FastICA dans le cas où la taille de l'échantillon est finie ou infinie, et nous avons établi cinq critères pour le choix des fonctions de non-linéarité. Dans les trois premiers chapitres, nous avons introduit le problème de l'ICA et revisité les résultats existants. Dans le Chapitre 4, nous avons étudié la convergence du FastICA empirique et le lien entre la limite de FastICA empirique et les points critiques de la fonction de contraste empirique. Dans le Chapitre 5, nous avons utilisé la technique du M-estimateur pour obtenir la normalité asymptotique et la matrice de covariance asymptotique de l'estimateur FastICA. Ceci nous a permis aussi de déduire quatre critères pour choisir les fonctions de non-linéarité. Un cinquième critère de choix de non-linéarité a été étudié dans le chapitre 6. Ce critère est basé sur une étude fine de la vitesse de convergence de FastICA empirique. Nous avons illustré chaque chapitre par des résultats numériques qui valident nos résultats théoriques. / The FastICA algorithm is one of the most popular algorithms in the domain of Independent Component Analysis (ICA). There exist two versions of FastICA: the one that corresponds to the ideal case that the sample size is infinite, and the one that deal with the practical situation, where a sample of finite size is available. In this thesis, we made a detailed study of the rate of convergence of the FastICA algorithm of both versions, and we established five criteria for the choice of the non-linearity function. In the first three chapters, we introduced the problem of ICA and revisited the classical results. In Chapitre 4, we studied the convergence of empirical FastICA and the link between the limit of empirical FastICA and the critical points of the empirical contrast function. In Chapter 5, we used the technique of M-estimator to obtain the asymptotic normality and the asymptotic covariance matrix of the FastICA estimator. This allowed us to derive four criteria to choose the non-linearity function. A fifth criterion for the choice of the non-linearity function was studied in Chapter 6. This criterion is based on the rate of convergence of the empirical FastICA algorithm. At the end of each chapter, we provided numerical simulations that validate our theoretical results.
76

New results in the multiscale analysis on perforated domains and applications

Onofrei, Daniel T 23 April 2007 (has links)
Multiscale phenomena implicitly appear in every physical model. The understanding of the general behavior of a given model at different scales and how one can correlate the behavior at two different scales is essential and can offer new important information. This thesis describes a series of new techniques and results in the analysis of multi-scale phenomena arising in PDEs on variable geometries. In the Second Chapter of the thesis, we present a series of new error estimate results for the periodic homogenization with nonsmooth coefficients. For the case of smooth coefficients, with the help of boundary layer correctors, error estimates results have been obtained by several authors (Oleinik, Lions, Vogelius, Allaire, Sarkis). Our results answer an open problem in the case of nonsmooth coefficients. Chapter 3 is focused on the homogenization of linear elliptic problems with variable nonsmooth coefficients and variable domains. Based on the periodic unfolding method proposed by Cioranescu, Damlamian and Griso in 2002, we propose a new technique for homogenization in perforated domains. With this new technique classical results are rediscovered in a new light and a series of new results are obtained. Also, among other advantages, the method helps one prove better corrector results. Chapter 4 is dedicated to the study of the limit behavior of a class of Steklov-type spectral problems on the Neumann sieve. This is equivalent with the limit analysis for the DtN-map spectrum on the sieve and has applications in the stability analysis of the earthquake nucleation phase model studied in Chapter 5. In Chapter 5, a $Gamma$-convergence result for a class of contact problems with a slip-weakening friction law, is described. These problems are associated with the modeling of the nucleation phase in earthquakes. Through the $Gamma$-limit we obtain an homogenous friction law as a good approximation for the local friction law and this helps us better understand the global behavior of the model, making use of the micro-scale information. As to our best knowledge, this is the first result proposing a homogenous friction law for this earthquake nucleation model.
77

Convergence of empirical probability measures

Yukich, Joseph January 1982 (has links)
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE / Bibliography: leaves 89-93. / by Joseph Yukich. / Ph.D.
78

Cultural Evolution and Advertising Strategies : Which future for TV commercials?

Bonesire, Thomas, Bouvy, François January 2009 (has links)
<p>This thesis deals with TV advertising strategies, namely adaptation and standardization, and with the impact of cultural homogenization on these strategies. Indeed, globalization generates the convergence of world cultures and especially of young Europeans’ cultures. This relative convergence in people’s habits, behaviour and values could allow advertisers to use more standardized advertisements without losing too much impact on the consumer. The use of standardized advertisements is interesting to create a uniform brand image, appeal to cross-border segments and, of course, make economies of scale. This thesis surveys young Europeans, represented by Swedes and Belgians, to examine their degree of cultural homogenization, i.e., if they are culturally similar enough for standardization to be effective on this group. Moreover, it compares the impact of both adapted and standardized commercials on this young European audience. This study comes to two main findings. First, the young Swedish and Belgian cultures have similarities, which standardized commercials can exploit, but also differences. This shows that we can speak about cultures’ convergence but not about a complete homogenization. Second, standardization seems to be effective - as effective as adaptation - in its appeal to young Swedes and Belgians. This shows that, given its advantages, standardization is certainly the most adequate method for targeting a young European audience. The findings for Sweden and Belgium should be valid for the whole EU. The thesis also discusses the generalization of the findings to the rest of the world and other age ranges as well as the future of commercials.</p>
79

Near Point of Convergence : A Comparison of Four Different Target types

Berglund Pilgrim, Caroline January 2010 (has links)
Purpose: The purpose of this study was to determine if there were any differences between four different target types when measuring the near point of convergence in adults. Methods and Material: The near point of convergence was measured in 35 subjects with a visual acuity of at least 1.0 (6/6) in each eye and without any strabismus. The targets used were: the tip of a pen, an accommodative target, the RAF line target and a penlight viewed through red-green filters. Both break and recovery points were assessed for the different techniques. Each target was used twice in consecutive order. The line target from RAF ruler was copied on to a small plastic ruler in order to be able to use the same ruler for measuring the results. All subjects were fitted with their best correction in the trial frame after a complete refraction. The measurements were taken to the nearest 0.25cm. Results: There was no difference found between NPC break values for the different target types in the control group. The NPC values were found to be 5.0/7.4 in the control group and 10.8/18.2 in the anomalous group. The accommodative target was found to give more remote values (11.5cm) than expected in comparison to the other targets in the anomalous group. Conclusion: In patients with normal NPC, the measurements can be taken with line target or Acc. target. Patients with receded NPC values should be evaluated with penlight and red-green glasses or at least twice with the tip of a pen.
80

Cultural Evolution and Advertising Strategies : Which future for TV commercials?

Bonesire, Thomas, Bouvy, François January 2009 (has links)
This thesis deals with TV advertising strategies, namely adaptation and standardization, and with the impact of cultural homogenization on these strategies. Indeed, globalization generates the convergence of world cultures and especially of young Europeans’ cultures. This relative convergence in people’s habits, behaviour and values could allow advertisers to use more standardized advertisements without losing too much impact on the consumer. The use of standardized advertisements is interesting to create a uniform brand image, appeal to cross-border segments and, of course, make economies of scale. This thesis surveys young Europeans, represented by Swedes and Belgians, to examine their degree of cultural homogenization, i.e., if they are culturally similar enough for standardization to be effective on this group. Moreover, it compares the impact of both adapted and standardized commercials on this young European audience. This study comes to two main findings. First, the young Swedish and Belgian cultures have similarities, which standardized commercials can exploit, but also differences. This shows that we can speak about cultures’ convergence but not about a complete homogenization. Second, standardization seems to be effective - as effective as adaptation - in its appeal to young Swedes and Belgians. This shows that, given its advantages, standardization is certainly the most adequate method for targeting a young European audience. The findings for Sweden and Belgium should be valid for the whole EU. The thesis also discusses the generalization of the findings to the rest of the world and other age ranges as well as the future of commercials.

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