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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.
241

Grammaires de graphes et langages formels / Graph grammars and formal languages

Dinh, Trong Hiêu 11 July 2011 (has links)
Cette thèse apporte plusieurs contributions dans le domaine des langages formels. Notre premier travail a été de montrer la pertinence des grammaires de graphes comme outil de démonstration de résultats fondamentaux sur les langages algébriques. Nous avons ainsi reformulé avec un point de vue géométrique les démonstrations du lemme des paires itérantes et du lemme de Parikh. Nous avons ensuite étendu aux graphes réguliers des algorithmes de base sur les graphes finis, notamment pour calculer des problèmes de plus court chemin. Ces extensions ont été faites par calcul de plus petits points fixes sur les grammaires de graphes. Enfin, nous avons caractérisé des familles générales de systèmes de récriture de mots dont la dérivation préserve la régularité ou l’algébricité. Ces familles ont été obtenues par décomposition de la dérivation en une substitution régulière suivie de la dérivation du système de Dyck / Pas de résumé en anglais
242

A construção de significados dos números irracionais no ensino básico: uma proposta de abordagem envolvendo os eixos constituintes dos números reais / The Construction of Irrational Numbers Meaning on Basic School: And approach proposal involving Real Numbers Axes constituents

Pommer, Wagner Marcelo 09 August 2012 (has links)
Considerando-se como fonte primária os manuais escolares brasileiros de Matemática, o saber a ser ensinado ainda situa uma apresentação dual, polarizado no viés pragmático ou teórico, ao que se segue um procedimento temático padrão que privilegia o desenvolvimento operatório envolvendo contextos exatos, finitos e determinísticos. Em particular, essas características se acentuam gravemente no momento de introdução dos números irracionais no ensino básico, o que ocasiona uma abordagem restritiva. Para superar este quadro, Bruner (1987) fundamenta que não devemos adiar o ensino de assuntos essenciais com base na crença de que são difíceis demais, pois as ideias fundamentais de qualquer assunto podem ser ensinadas na escolaridade básica, porém demanda um trabalho para além dos aspectos técnicos, o que equivale a retomada de características ligadas à compreensão. Neste trabalho, tivemos por hipótese que os pares discreto/contínuo; exato/aproximado; finito/infinito, presentes na análise da evolução epistemológica dos números reais e descritos em Machado (2009), se constituem em pilares conceituais essenciais para fundamentar um panorama favorável a uma abordagem significativa do tema dos números irracionais, de modo a compor um amálgama entre os aspectos técnicos e semânticos. Em face da necessária reflexão, em nível educacional, em torno de tal tema, delimitamos inicialmente um contexto investigativo pautado em um estudo qualitativo orientado pela questão Como são abordados os números irracionais no ensino básico, considerando-se como fonte o livro didático de Matemática?, a fim de mapear a apresentação deste assunto no Ensino Fundamental II e no Ensino Médio. O fundamento metodológico se inspirou nos núcleos de significação, descritos em Aguiar&Ozella (2006), que buscou apreender os sentidos que constituem o conteúdo do discurso expresso nos textos dos livros didáticos. O percurso dos núcleos de significação confirmou que, nos livros didáticos analisados, a apresentação dos números irracionais ocorre de modo polarizado: alguns optam por um viés empírico e outros pela definição formal. Verificou-se que, após uma abordagem inicial, não ocorre intercâmbio destas opções, o que acarreta um rápido esgotamento das ferramentas para se desenvolver as temáticas, limitando a compreensão da complexidade dos números irracionais no ensino básico. A partir das hipóteses e da pesquisa empírica, nos propusemos a delinear as contribuições presentes no movimento dialético entre os pares discreto/contínuo, finito/infinito e exato/aproximado, cujas mútuas conexões permeiam um espaço de significações, um campo que possibilita organizar, tecer e ampliar a rede de significados, conforme Machado (1995), favorecendo um quadro de maior compreensão à apresentação dos números irracionais. O enfoque epistemológico realizado revelou uma multiplicidade de relações envolvendo os números irracionais e diversos assuntos do currículo de Matemática, não devidamente caracterizadas e exploradas no ensino básico, o que serviu de mote para a apresentação de algumas situações de ensino para ilustrar os aportes orientadores sugeridos. Acreditamos que o caminho epistemológico trilhado viabilizou uma abertura para ampliar o quadro de significados em relação a outros tópicos presentes na Matemática Elementar, considerando-se como suporte a potencialidade presente nos eixos discreto/contínuo; exato/aproximado; finito/infinito, assim como no par determinístico/aleatório. / Considering Brazilian mathematics school textbooks as a primary research source, the knowledge to be taught still has a dual presentation, polarized in a pragmatic or theoretical way, what follows a thematic procedure pattern that favors an operational development involving exact, finite and deterministic contexts. In particular, these characteristics are seriously accentuated by the time of irrational numbers introduction at basic education, which leads to a restrictive approach. To overcome this situation, Bruner (1987) states that we should not postpone teaching key issues based on the belief that they are too hard, because the fundamental ideas of any subject can be taught at basic education, but it demands a work that overcome technical aspects, considerations that are equivalent to the resumption with aspects related to understanding. In this work, we had by hypothesis that the tension inherent on discrete/continuous, exact/approximate, finite/infinite pairs, extracted from analyses on real numbers epistemological evolution and described at Machado (2009), constitutes an essential conceptual pillar to establish a helpful framework to enable a significant irrational numbers approach, in order to compose an amalgam between technical and semantic aspects. Considering the necessary educational discussion involving this theme, we initially delimited an investigative context based on a qualitative study guided by the question How irrational numbers are approached in basic education, considering mathematics textbook as a source?\' in order to map this subject presentation at Middle and High School. The methodological foundation was inspired in meaning core, described in Aguiar and Ozella (2006), which aims to capture the sense that constitutes the speech content expressed inside mathematics scholar textbooks. The analysis from meaning core route reveals that, in the textbooks examined, the most known irrational numbers introduction occurs in a polarized way: some opt for a pragmatic bias and others by formal definition. However, it was found that after an initial approach, there is no further relationship between these options, which causes a rapid depletion of the tools to develop these themes, which limits the complexity understanding of irrational numbers in basic education. From the hypotheses and the empirical research, we intended to delineate contributions presented on the dialectical movement between discrete/continuous, finite/infinite and exact/approximate pairs, whose mutual connections permeate a \'space of meanings\', a field that allows to organize, to weave and to expand a network of meanings, as Machado (1995), favoring a framework for better understanding the irrational numbers development in basic school. The epistemological approach performed revealed a multiplicity of relationships involving irrational numbers and various subjects of mathematics curriculum, not properly characterized and exploited in basic education, references which served as contexts for the presentation of some teaching situations to illustrate the contributions guidance suggested. We believe that the epistemological path trodden enables an opening to increase possibilities of meanings in relation to other topics of Elementary Mathematics, considering as support the capability constituents presented in discrete/continuous, exact/approximate, finite/infinity axis, as well as in deterministic/random pair.
243

O infinito: um obstáculo no estudo da Matemática / The infinite: an obstacle in the study of the mathematics

Amadei, Flavio Luiz 17 June 2005 (has links)
Made available in DSpace on 2016-04-27T16:58:42Z (GMT). No. of bitstreams: 1 dissertacao_flavio_luiz_amadei.pdf: 355407 bytes, checksum: 9113491693f07d1f5b01c29d5008a168 (MD5) Previous issue date: 2005-06-17 / nenhum / The research here presented approaches the notion of infinite under some different views, with the main purpose of indicating how imbricated was its formation as a mathematical concept and its consequences to the learning of mathematics. This research is supported by bibliographical study, presentation and analysis of the literature currently available on this subject. Some introductory mathematical concepts are presented on the notion of infinite, some aspects of the historical evolution of this notion in Mathematics, with special consideration to Bolzano s work The Paradoxes of Infinite , and data from other researches in the field of Mathematics Education. Analysis that intent to underline relationships between the epistemological and historical process of the notion of infinite, specially actual infinite, and the developmental process of human thinking in the learning of Mathematics, are presented as a conclusion / A pesquisa aqui apresentada visa abordar a noção de infinito sob alguns pontos de vista, com o objetivo principal de indicar quão imbricada foi a sua formação como conceito matemático e suas conseqüências para a aprendizagem da matemática. Esta pesquisa é desenvolvida a partir de estudo bibliográfico, apresentação e análise de textos sobre o assunto. São apresentados alguns conceitos introdutórios sobre a noção de infinito, alguns aspectos da evolução histórica dessa noção na matemática com destaque especial à obra "Os Paradoxos do Infinito" de Bolzano e resultados de pesquisas no âmbito da Educação Matemática. Análises que objetivam evidenciar relações existentes entre o processo epistemológico e histórico da noção de infinito, em especial do infinito atual e os processos de desenvolvimento do pensamento humano na aprendizagem da matemática, são apresentadas como fechamento
244

Sobre a incomunicabilidade humana / Sobre a incomunicabilidade humana

Alves, Claudenir Modolo 05 June 2009 (has links)
Esta dissertação versa sobre a incomunicabilidade humana. A pergunta problematizadora que temos como objetivo aprofundar é: o ser humano é, ontologicamente, um ser capaz de se comunicar? ou de outra forma: é possível a existência da comunicação? A hermenêutica imanente dos textos de natureza filosófica, seguida da reflexão analítica, nos aproxima da problemática sobre a incomunicabilidade humana, iluminando os enfoques chave do estado instaurado de incomunicação radical e generalizada, por outro lado a possibilidade do ser de relacionar-se e abrir a comunicação para sua existência. A possibilidade do ser humano de relacionar-se é mínima no sistema planetário de comunicação, o que nos faz concluir que vivemos na era da incomunicabilidade humana, por primeiro da incomunicabilidade entre eu e o outro. / This dissertation deals with human incommunicability. We intend to further study the following problematizing issue: Ontologically speaking, is the human being capable of communicating? In other words: can communication exist? The immanent hermeneutics of philosophical texts, followed by analytical reflection, leads us to the problem of human incommunicability, throws light on key approaches to the state of radical and generalized incommunication, and, on the other hand, the possibility for human beings to establish relationships and open lines of communication for their survival. The planets communication system allows for minimal possibilities of human beings establishing relationships; we have, therefore, to conclude that we live in an era of human incommunicability, starting with the incommunicability between the self and others.
245

ε-SUPERPOSITION AND TRUNCATION DIMENSIONS IN AVERAGE AND PROBABILISTIC SETTINGS FOR ∞-VARIATE LINEAR PROBLEMS

Dingess, Jonathan M. 01 January 2019 (has links)
This thesis is a representation of my contribution to the paper of the same name I co-author with Dr. Wasilkowski. It deals with linear problems defined on γ-weighted normed spaces of functions with infinitely many variables. In particular, I describe methods and discuss results for ε-truncation and ε-superposition methods. I show through these results that the ε-truncation and ε-superposition dimensions are small under modest error demand ε. These positive results are derived for product weights and the so-called anchored decomposition.
246

張湛《列子注》貴虛思想研究 / A Study on Chang - Chan's Theories of Emptiness from the Book of 《Lieh Tzu Chu》

吳慕雅, Wu, Mu Ya Unknown Date (has links)
張湛《列子注》長久以來在學術界未受到重視,但是在整個魏晉玄學的發展史上(尤其是東晉玄學)實具有不可磨滅的價值,因此對於張湛的玄學思想應給予什麼樣的評價?張湛的「貴虛」思想與《列子》的「貴虛」究竟有什麼不同?他的理論是否可以名之為「貴虛論」?張湛的思想體系只是單純的雜揉各家的說法、還是又提出了一些新的命題及概念?這些都是在探討張湛思想所欲解決的問題。本文擬分為六章,以「貴虛」為理論核心,再探討相關的幾個重要的子題--言意觀、力命論、天道觀、聖人論等,將張湛的行為及思考模式作一時代的定位。本文各章重點如下:第一章緒論,先宏觀介紹東晉玄學的特色及《列子注》「貴虛」的意涵,並對張湛是否偽作《列子》疑案作一釐清。第二章言意觀,說明《列子注》言意之辨的內涵,從去知忘言的語言模式及名實與公私二方面論述。進而再探討張湛的思考脈絡及思維方式。第三章天道觀,探討有無之辨的思想背景及思想內涵,從道與的關係、萬有生化的情形、宇宙的生成三方面申說。第四章力命論,主要探討理與力命的關係及「為我」與「知命」觀念的矛盾與調和。第五章聖人之道,說明張湛「聖人」模式的內涵及儒道調和的意義,並進一步闡明張湛對於覺與夢的辨別及具體的修養之方。第六章結論,對張湛思想體系的檢討及評價。
247

Subordinação Adverbial : um estudo cognitivo sobre o infinitivo, o clítico SE e as formas verbais finitas em proposições adverbiais do Português Europeu / Adverbial subordination : a cognitive study on the infinitive, the clitic SE and finite verb forms in European Portuguese adverbial clauses

Vesterinen, Rainer January 2006 (has links)
<p>The aim of this study is to analyse the variation between infinitive and finite verb adverbial clauses in European Portuguese. In order to understand this variation, three central questions are raised: (1) What determines the use of the uninflected vs. the inflected infinitive in same-subject adverbial clauses? (2) What does the pronoun SE signal in these adverbial clauses? (3) What difference is there between the use of the inflected infinitives vs. finite verbs in different subject adverbial clauses?</p><p>Earlier investigations about these three questions are discussed. One conclusion of this review is that former research almost exclusively has been conducted from a traditional or formalistic point of view that has given priority to structural descriptions instead of semantic or conceptual explanations. In contrast to this, the present study endeavours to examine these issues from a cognitive linguistic perspective.</p><p>It is claimed that the use of the inflected infinitive in adverbial same-subject clauses may be explained by contextual factors which create a cognitive need to highlight the subject of the adverbial clause. Further, an analysis about how the grammatical micro-context can determine the interpretation of the clitic pronoun SE as a marker for a generic trajector is conducted. It is also argued that the difference between infinitive and finite adverbial clauses can bee explained by means of theories of subjectification and mental spaces.</p><p>The conclusion is drawn that a cognitive approach to grammar can, indeed, shed light on the issues considered. In particular, it is shown that different adverbial constructions can express different conceptual meaning. In the light of this fact, other issues concerned with finite and infinite verb forms are raised.</p>
248

Becoming the New Man in Post-PostModernist Fiction: Portrayals of Masculinities in David Foster Wallace's Infinite Jest and Chuck Palahnuik's Fight Club

Delfino, Andrew Steven 03 May 2007 (has links)
While scholars have analyzed the masculinity crisis portrayed in American fiction, few have focused on postmodernist fiction, few have examined masculinity without using feminist theory, and no articles propose an adequate solution for ending normative masculinity’s dominance. I examine the masculinity crisis as it is portrayed in two postmodernist novels, David Foster Wallace’s novel Infinite Jest and Chuck Palahniuk’s novel Fight Club. Both novels have male characters that ran the gamut of masculinities, but those that are the most successful at avoiding gender stereotypes (Donald Gately in Infinite Jest, and the narrator in Fight Club) develop a masculinity which incorporates strong, phallic masculinity and nurturing, testicular masculinity, creating a balanced gender. At the same time, both novels examine postmodernist fiction’s future. Post-postmodernist fiction, similar to well-rounded masculinity, seeks to be more emotionally open with the reader while still using irony and innovation for meaningful effects, not just to be clever.
249

Reciprocal classes of Markov processes : an approach with duality formulae

Murr, Rüdiger January 2012 (has links)
This work is concerned with the characterization of certain classes of stochastic processes via duality formulae. In particular we consider reciprocal processes with jumps, a subject up to now neglected in the literature. In the first part we introduce a new formulation of a characterization of processes with independent increments. This characterization is based on a duality formula satisfied by processes with infinitely divisible increments, in particular Lévy processes, which is well known in Malliavin calculus. We obtain two new methods to prove this duality formula, which are not based on the chaos decomposition of the space of square-integrable function- als. One of these methods uses a formula of partial integration that characterizes infinitely divisible random vectors. In this context, our characterization is a generalization of Stein’s lemma for Gaussian random variables and Chen’s lemma for Poisson random variables. The generality of our approach permits us to derive a characterization of infinitely divisible random measures. The second part of this work focuses on the study of the reciprocal classes of Markov processes with and without jumps and their characterization. We start with a resume of already existing results concerning the reciprocal classes of Brownian diffusions as solutions of duality formulae. As a new contribution, we show that the duality formula satisfied by elements of the reciprocal class of a Brownian diffusion has a physical interpretation as a stochastic Newton equation of motion. Thus we are able to connect the results of characterizations via duality formulae with the theory of stochastic mechanics by our interpretation, and to stochastic optimal control theory by the mathematical approach. As an application we are able to prove an invariance property of the reciprocal class of a Brownian diffusion under time reversal. In the context of pure jump processes we derive the following new results. We describe the reciprocal classes of Markov counting processes, also called unit jump processes, and obtain a characterization of the associated reciprocal class via a duality formula. This formula contains as key terms a stochastic derivative, a compensated stochastic integral and an invariant of the reciprocal class. Moreover we present an interpretation of the characterization of a reciprocal class in the context of stochastic optimal control of unit jump processes. As a further application we show that the reciprocal class of a Markov counting process has an invariance property under time reversal. Some of these results are extendable to the setting of pure jump processes, that is, we admit different jump-sizes. In particular, we show that the reciprocal classes of Markov jump processes can be compared using reciprocal invariants. A characterization of the reciprocal class of compound Poisson processes via a duality formula is possible under the assumption that the jump-sizes of the process are incommensurable. / Diese Arbeit befasst sich mit der Charakterisierung von Klassen stochastischer Prozesse durch Dualitätsformeln. Es wird insbesondere der in der Literatur bisher unbehandelte Fall reziproker Klassen stochastischer Prozesse mit Sprungen untersucht. Im ersten Teil stellen wir eine neue Formulierung einer Charakterisierung von Prozessen mit unabhängigen Zuwächsen vor. Diese basiert auf der aus dem Malliavinkalkül bekannten Dualitätsformel für Prozesse mit unendlich oft teilbaren Zuwächsen. Wir präsentieren zusätzlich zwei neue Beweismethoden dieser Dualitätsformel, die nicht auf der Chaoszerlegung des Raumes quadratintegrabler Funktionale beruhen. Eine dieser Methoden basiert auf einer partiellen Integrationsformel fur unendlich oft teilbare Zufallsvektoren. In diesem Rahmen ist unsere Charakterisierung eine Verallgemeinerung des Lemma fur Gaußsche Zufallsvariablen von Stein und des Lemma fur Zufallsvariablen mit Poissonverteilung von Chen. Die Allgemeinheit dieser Methode erlaubt uns durch einen ähnlichen Zugang die Charakterisierung unendlich oft teilbarer Zufallsmaße. Im zweiten Teil der Arbeit konzentrieren wir uns auf die Charakterisierung reziproker Klassen ausgewählter Markovprozesse durch Dualitätsformeln. Wir beginnen mit einer Zusammenfassung bereits existierender Ergebnisse zu den reziproken Klassen Brownscher Bewegungen mit Drift. Es ist uns möglich die Charakterisierung solcher reziproken Klassen durch eine Dualitätsformel physikalisch umzudeuten in eine Newtonsche Gleichung. Damit gelingt uns ein Brückenschlag zwischen derartigen Charakterisierungsergebnissen und der Theorie stochastischer Mechanik durch den Interpretationsansatz, sowie der Theorie stochastischer optimaler Steuerung durch den mathematischen Ansatz. Unter Verwendung der Charakterisierung reziproker Klassen durch Dualitätsformeln beweisen wir weiterhin eine Invarianzeigenschaft der reziproken Klasse Browscher Bewegungen mit Drift unter Zeitumkehrung. Es gelingt uns weiterhin neue Resultate im Rahmen reiner Sprungprozesse zu beweisen. Wir beschreiben reziproke Klassen Markovscher Zählprozesse, d.h. Sprungprozesse mit Sprunghöhe eins, und erhalten eine Charakterisierung der reziproken Klasse vermöge einer Dualitätsformel. Diese beinhaltet als Schlüsselterme eine stochastische Ableitung nach den Sprungzeiten, ein kompensiertes stochastisches Integral und eine Invariante der reziproken Klasse. Wir präsentieren außerdem eine Interpretation der Charakterisierung einer reziproken Klasse im Rahmen der stochastischen Steuerungstheorie. Als weitere Anwendung beweisen wir eine Invarianzeigenschaft der reziproken Klasse Markovscher Zählprozesse unter Zeitumkehrung. Einige dieser Ergebnisse werden fur reine Sprungprozesse mit unterschiedlichen Sprunghöhen verallgemeinert. Insbesondere zeigen wir, dass die reziproken Klassen Markovscher Sprungprozesse vermöge reziproker Invarianten unterschieden werden können. Eine Charakterisierung der reziproken Klasse zusammengesetzter Poissonprozesse durch eine Dualitätsformel gelingt unter der Annahme inkommensurabler Sprunghöhen.
250

A Semismooth Newton Method For Generalized Semi-infinite Programming Problems

Tezel Ozturan, Aysun 01 July 2010 (has links) (PDF)
Semi-infinite programming problems is a class of optimization problems in finite dimensional variables which are subject to infinitely many inequality constraints. If the infinite index of inequality constraints depends on the decision variable, then the problem is called generalized semi-infinite programming problem (GSIP). If the infinite index set is fixed, then the problem is called standard semi-infinite programming problem (SIP). In this thesis, convergence of a semismooth Newton method for generalized semi-infinite programming problems with convex lower level problems is investigated. In this method, using nonlinear complementarity problem functions the upper and lower level Karush-Kuhn-Tucker conditions of the optimization problem are reformulated as a semismooth system of equations. A possible violation of strict complementary slackness causes nonsmoothness. In this study, we show that the standard regularity condition for convergence of the semismooth Newton method is satisfied under natural assumptions for semi-infinite programs. In fact, under the Reduction Ansatz in the lower level problem and strong stability in the reduced upper level problem this regularity condition is satisfied. In particular, we do not have to assume strict complementary slackness in the upper level. Furthermore, in this thesis we neither assume strict complementary slackness in the upper nor in the lower level. In the case of violation of strict complementary slackness in the lower level, the auxiliary functions of the locally reduced problem are not necessarily twice continuously differentiable. But still, we can show that a standard regularity condition for quadratic convergence of the semismooth Newton method holds under a natural assumption for semi-infinite programs. Numerical examples from, among others, design centering and robust optimization illustrate the performance of the method.

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