51 |
Thermodynamic formalism, statistical properties and multifractal analysis of non-uniformly hyperbolic systemsWang, Tianyu 20 October 2021 (has links)
No description available.
|
52 |
Use Of Web-Based Lessons Of Statistical Concepts With Graphics And Animation To Enhance The Effectiveness Of LearningPillala, Lavanya 26 March 2010 (has links)
No description available.
|
53 |
A unified approach to structural change tests based on F statistics, OLS residuals, and ML scoresZeileis, Achim January 2005 (has links) (PDF)
Three classes of structural change tests (or tests for parameter instability) which have been receiving much attention in both the statistics and econometrics communities but have been developed in rather loosely connected lines of research are unified by embedding them into the framework of generalized M-fluctuation tests (Zeileis and Hornik, 2003). These classes are tests based on F statistics (supF, aveF, expF tests), on OLS residuals (OLS-based CUSUM and MOSUM tests) and on maximum likelihood scores (including the Nyblom-Hansen test). We show that (represantives from) these classes are special cases of the generalized M-fluctuation tests, based on the same functional central limit theorem, but employing different functionals for capturing excessive fluctuations. After embedding these tests into the same framework and thus understanding the relationship between these procedures for testing in historical samples, it is shown how the tests can also be extended to a monitoring situation. This is achieved by establishing a general M-fluctuation monitoring procedure and then applying the different functionals corresponding to monitoring with F statistics, OLS residuals and ML scores. In particular, an extension of the supF test to a monitoring scenario is suggested and illustrated on a real-world data set. / Series: Research Report Series / Department of Statistics and Mathematics
|
54 |
Théorèmes limites dans l'analyse statistique des systèmes dynamiques / Limit theorems in the statistical analysis of dynamical systemsAbdelkader, Mohamed 30 November 2017 (has links)
Dans cette thèse nous étudions les théorèmes limites dans l’analyse statistique dessystèmes dynamiques. Le premier chapitre est consacré aux notions des bases des systèmesdynamiques ainsi que la théorie ergodique. Dans le deuxième chapitre nous introduisonsun cadre fonctionnel abstrait pour lequel la version quenched du théorème de la limitecentrale (TLC) en dimension 1 pour les systèmes dynamiques uniformément dilatantsest satisfaite sous une condition de validité nécessaire et suffisante. Le troisième chapitreest consacré au principe d’invariance presque sûr (PIPS) pour les application aléatoiresdilatantes par morceaux. Nous présentons certaines hypothèses sous lesquelles le (PIPS)est vérifié en utilisant la méthode d’approximation des martingales de Cuny et Merlèvede.Nous étudions aussi le théorème de Sprindzuk et ses conséquences. Nous établissons dansle chapitre quatre la décroissance des corrélations pour les systèmes dynamiques aléatoiresuniformément dilatants par la méthode de couplage en dimension 1. Nous terminons cetravail par une présentation des concepts de base de la théorie des mesures et probabilitéset une présentation de l’espace des fonctions à variation bornée. / In this thesis we study the limit theorems in the statistical analysis of dynamicalsystems. The first chapter is devoted to the basic notions in dynamical systems as well asthe ergodic theory. In the second chapter we introduce an abstract functional frameworkunder which the quenched version of the central limit theorem (CLT) in dimension 1for uniformly expanding dynamic systems is satisfied under a necessary and sufficientcondition validity. The third chapter is devoted to the almost sure invariance principle(ASIP) for random piecewise expanding maps. We present some hypotheses under whichthe (ASIP) is verified using the method of approximation of the martingales of Cuny andMerlèvede. We also study the Sprindzuk theorem and its consequences. In chapter four,we define the decay of correlations for the random dynamical systems uniformly expandingby the coupling method in dimension 1. We finish this work with a presentation of thebasic concepts of the theory of measures and probabilities and a presentation of the spaceof functions with bounded variation.
|
55 |
An exploratory study of the effectiveness of computer graphic and simulations in a computer-student interactive environment in illustrating random sampling and the central limit theoremUnknown Date (has links)
"The purposes of this study were: (1) to investigate the effectiveness of the computer-student interactive method in presenting statistical concepts and in instructing students in the applications of these concepts, and (2) to develop instruments that test for the understanding of these concepts and the mastery of these application skills"--Abstract. / Typescript. / "Spring Semester, 1990." / "Submitted to the Department of Curriculum and Instruction in partial fulfillment of the requirements for the degree of Doctor of Philosophy." / Advisor: E. T. Denmark, Professor Directing Dissertation. / Includes bibliographical references.
|
56 |
Marches aléatoires en environnement aléatoire faiblement elliptique / Random walks in weakly elliptic random environmentBouchet, Élodie 30 June 2014 (has links)
Cette thèse est dédiée à l'étude des marches aléatoires en milieu aléatoire sur Zd. On s'intéresse tout particulièrement aux environnements qui sont elliptiques, mais pas uniformément elliptiques, et qui peuvent donc contenir des pièges sur lesquels la marche passe beaucoup de temps. Le premier résultat de cette thèse (chapitre 4) concerne les environnements de Dirichlet, qui forment une sous-classe de marches aléatoires en milieu aléatoire présentant des propriétés remarquables. On se place en dimension d≥ 3 et on étudie le cas où les pièges dus à la non-uniforme ellipticité sont prépondérants. Dans ce contexte, on montre l'équivalence des points de vue statique et dynamique pour une marche accélérée. Ceci permet de compléter les résultats de transience et récurrence directionnelles obtenus par Sabot, et de donner le degré polynomial de l'éloignement de la marche par rapport à l'origine dans le cas sous-balistique et transient. On se place ensuite (chapitre 5) dans le cas des marches transientes dans une direction, et on étudie les conditions sur la loi de l'environnement nécessaires pour assurer l'existence de moments pour les temps de renouvellement. On améliore ainsi les résultats obtenus par Campos et Ramírez. Dans la dernière partie (chapitre 6), on étudie les conditions d'application du théorème central limite quenched dans le cas des marches aléatoires balistiques. Sous la condition supplémentaire (T), on affaiblit les hypothèses sur l'intégrabilité des temps de renouvellement des travaux de Rassoul-Agha et Seppäläinen et de Berger et Zeitouni : on arrive à la condition E (τ12+ε) < +∞ (pour le théorème annealed la condition optimale est E (τ12) < +∞) / In this thesis we study random walks in random environment on Zd. We are particularly interested in environments that are elliptic, but not uniformly elliptic. Those environments can contain traps on which the walk spends a lot of time. The first results in this thesis (chapter 4) deal with the particular case of Dirichlet environments. Random walks in Dirichlet environment form a sub-class of random walks in random environment with specific properties. We consider dimensions d 3 and we study the behavior of the walk when the traps created by the non-uniform ellipticity play an important part. In this context, we show the equivalence between the static and dynamic points of view for an accelerated walk. This completes the results of directional transience and recurrence obtained by Sabot, and it allows to find the polynomial order of the magnitude of the walk’s displacement in the sub-ballistic transient case. Then (chapter 5) we consider the case of directionally transient walks, and we study the conditions on the law of the environment that ensure the existence of moments for the regeneration times. We thus improve the results obtained by Campos and Ramírez. In the last section (chapter 6), we consider the case of ballistic random walks and we study the conditions under which a quenched central limit theorem holds. Under the additional assumption (T), we weaken the integrability of the regeneration times necessary for the works of Rassoul- Agha and Seppäläinen, and Berger and Zeitouni. We obtain the condition E (τ12+ε) < +∞ (whereas for the annealed theorem, the optimal condition is E (τ12) < +∞)
|
57 |
O teorema central do limite: um estudo ecológico do saber e do didáticoRodrigues, Chang Kuo 02 December 2009 (has links)
Made available in DSpace on 2016-04-27T16:59:00Z (GMT). No. of bitstreams: 1
Chang Kuo Rodrigues.pdf: 19165521 bytes, checksum: 423ed2c3982a3973f316dec156e2d596 (MD5)
Previous issue date: 2009-12-02 / This paper refers to the building of mathematical and/or statistical ideas and concepts
around Central Limit Theorem for Mathematics graduates.The investigation focuses
the importance of the theorem in Statistics Inference and its comprehension by the
professionals to be, who will act in Basic Education. Therefore, we chose to research
some books related to the teaching and learning process of the theorem and
emphasised its importance on the Mathematics teacher daily practice. The theoretical
approach is about Mathematics Teaching theories, particularly the Theory of Didactic
Transposition ( CHEVALLARD, 1985), with an echological approach under the
knowlwdge and teaching point of view ( ARTAUD, 1998). We chose methodological
procedures directed to the didactic design (ARTIGUE, 2009), with qualitative nature,
and whose assumptions are linked to Teaching Engineering (ARTIGUE, 1988). The
subjects of this investigation are the graduates who had some knowledge about
Basic Statistics and, from a previous analysis about the kind of knowledge they had
about the theme, we presented some activities in a problem-situation context
connected to the Mathematics teachers daily practice. The analysis of these results
allowed us to relate the existing problems between the subject and the students from
Basic Education, which involved statistics literacy. After these activities, there was a
dialogue, with discussions about the theme, allowing us to analyse how the ideas
and concepts around the Central Limit Theorem were built, being its comprehension
the main aim for the graduates. Besides that, we analysed some textbooks for higher
education, based on the Anthropological Theory of Didactic (CHEVALLARD, 1996,
1999), which also showed us the essential knowledge for the theorem to live ,
because the approach is under the knowledge and teaching echological point of
view. On the other hand, we detected what kind of limitations, or restrictions, exist in
the books analysed, interfering in the elaboration of the activities by the teacher.
Thus, our investigation reaffirms the importance of teaching and learning Statistics in
the various applications for the Mathematics teachers to be formation in a world
controlled by the technological advances, which interfere directly on the
understanding of the information we receive every moment / O presente trabalho refere-se à construção das ideias e dos conceitos matemáticos
e/ou estatísticos em torno do Teorema Central do Limite para os Licenciandos de
Matemática. O cerne da investigação limita-se à importância do teorema na
Inferência Estatística e à sua compreensão pelos futuros profissionais que atuarão
na Educação Básica. Nesse sentido, optamos por revisar algumas bibliografias que
têm relação com o processo de ensino e de aprendizagem do teorema e
enfatizamos sua importância na pratica do dia a dia do professor de Matemática. O
quadro teórico incide sobre as teorias da Didática da Matemática, particularmente, a
Teoria da Transposição Didática (CHEVALLARD, 1985), munido de uma abordagem
ecológica sob o ponto de vista do saber e do didático (ARTAUD, 1998). Optamos por
procedimentos metodológicos voltados para o design didático (ARTIGUE, 2009), de
cunho qualitativo e, cujos pressupostos estão aliados à Engenharia Didática
(ARTIGUE, 1988). Os sujeitos dessa investigação são os licenciandos que já
predispunham de conhecimentos sobre a Estatística Básica e, a partir de uma
análise prévia sobre que tipos de conhecimento eles já detinham sobre o tema,
apresentamos algumas atividades no contexto de uma situação-problema pertinente
ao cotidiano dos professores de Matemática. A análise desses resultados nos
propiciou interrelacionar as problemáticas existentes na disciplina de Matemática
com alunos da Educação Básica, envolvendo assim, a literacia estatística. Após a
realização dessas atividades, ocorreu também um diálogo, com discussões acerca
do tema, o que nos permitiu analisar como foram construídos as ideias e os
conceitos no entorno do Teorema Central do Limite, de modo que sua compreensão
fosse o principal alvo para os licenciandos. Além disso, analisamos alguns livrostexto
do ensino superior, à luz da Teoria Antropológica do Didático (CHEVALLARD,
1996, 1999), o que também nos indicou que saberes são indispensáveis de modo
que o teorema viva , já que a abordagem é sob o ponto de vista ecológico do saber
e do didático. Por outro lado, detectamos que tipos de limitações, ou restrições,
existem nas obras consultadas, interferindo assim, a elaboração das atividades por
parte do professor. Portanto, a nossa investigação reitera a importância do ensino e
da aprendizagem da Estatística nas diversas aplicações na formação dos futuros
professores de Matemática num mundo ditado pelos avanços tecnológicos, que
interferem diretamente na leitura de informações que recebemos a todo instante
|
58 |
Chaotické náhodné veličiny v aplikované pravděpodobnosti / Chaotic random variables in applied probabilityVečeřa, Jakub January 2019 (has links)
This thesis deals with modeling of particle processes. In the first part we ex- amine Gibbs facet process on a bounded window with discrete orientation distri- bution and we derive central limit theorem (CLT) for U-statistics of facet process with increasing intensity. We calculate all asymptotic joint moments for interac- tion U-statistics and use the method of moments for deriving the CLT. Moreover we present an alternative proof which makes use of the CLT for U-statistics of a Poisson facet process. In the second part we model planar segment processes given by a density with respect to the Poisson process. Parametric models involve reference distributions of directions and/or lengths of segments. Statistical methods are presented which first estimate scalar parameters by known approaches and then the reference distribution is estimated non-parametrically. We also introduce the Takacs-Fiksel estimate and demonstrate the use of estimators in a simulation study and also using data from actin fibres from stem cells images. In the third part we study a stationary Gibbs particle process with determin- istically bounded particles on Euclidean space defined in terms of a finite range potential and an activity parameter. For small activity parameters, we prove the CLT for certain statistics of this...
|
59 |
Mosaïques de Poisson-Voronoï sur une variété riemannienne / Poisson-Voronoi tessellation in a Riemannian manifoldChapron, Aurélie 20 November 2018 (has links)
Une mosaïque de Poisson-Voronoï est une partition aléatoire de l'espace euclidien en polyèdres, appelés cellules, obtenue à partir d'un ensemble aléatoire discret de points appelés germes. A chaque germe correspond une cellule, qui est l'ensemble des points de l'espace qui sont plus proches de ce germes que des autres germes. Ces modèles sont souvent utilisées dans divers domaines tels que la biologie, les télécommunications, l'astronomie, etc. Les caractéristiques de ces mosaïques et des cellules associées ont été largement étudiées dans l'espace euclidien mais les travaux sur les mosaïques de Voronoï dans un cadre non-euclidien sont rares.Dans cette thèse, on étend la définition de mosaïque de Voronoï à une variétériemannienne de dimension finie et on s'intéresse aux caractéristiques des cellules associées. Plus précisément, on mesure dans un premier temps l'influence que peut avoir la géométrie locale de la variété, c'est-à-dire les courbures sur les caractéristiques moyennes d'une cellule, comme son volume ou son nombre de sommets, en calculant des développements asymptotiques des ces caractéristiques moyennes à grande intensité. Dans un deuxième temps, on s'interroge sur la possibilité de retrouver la géométrie locale de la variété à partir des caractéristiques combinatoires de la mosaïque sur la variété. En particulier, on établit desthéorèmes limites, quand l'intensité du processus des germes tend vers l'infini, pour le nombre de sommets de la mosaïque dans une fenêtre, ce qui permet de construire un estimateur de la courbure et d'en donner quelques propriétés.Les principaux résultats de cette thèse reposent sur la combinaison de méthodesprobabilistes et de techniques issues de la géométrie différentielle. / A Poisson-Voronoi tessellation is a random partition of the Euclidean space intopolytopes, called cells, obtained from a discrete set of points called germs. To each germ corresponds a cell which is the set of the points of the space which are closer to this germ than to the other germs. These models are often used in several domains such as biology, telecommunication, astronomy, etc. The caracteristics of these tessellations and cells have been widely studied in the Euclidean space but only a few works concerns non-Euclidean Voronoi tessellation. In this thesis, we extend the definition of Poisson-Voronoi tessellation to a Riemannian manifold with finite dimension and we study the caracteristics of the associated cells. More precisely, we first measure the influence of the local geometry of the manifold, namely the curvatures, on the caracteristics of the cells, e.g. the mean volume or the mean number of vertices. Second, we aim to recover the local geometry of the manifold from the combinatorial properties of the tessellation on the manifolds. In particular, we establish limit theorems for the number of vertices of the tessellation, when the intensity of the process of the germs tends to infinity. This leads to the construction of an estimator of the curvature of the manifold and makes it possible to derive some properties of it. The main results of this thesis relies on the combination of stochastic methods and techniques from the differential geometry theory.
|
60 |
Gaussian structures and orthogonal polynomialsLarsson-Cohn, Lars January 2002 (has links)
<p>This thesis consists of four papers on the following topics in analysis and probability: analysis on Wiener space, asymptotic properties of orthogonal polynomials, and convergence rates in the central limit theorem. The first paper gives lower bounds on the constants in the Meyer inequality from the Malliavin calculus. It is shown that both constants grow at least like <i>(p-1)</i><sup>-1</sup> or like <i>p</i> when <i>p</i> approaches 1 or ∞ respectively. This agrees with known upper bounds. In the second paper, an extremal problem on Wiener chaos motivates an investigation of the <i>L</i><sup>p</sup>-norms of Hermite polynomials. This is followed up by similar computations for Charlier polynomials in the third paper. In both cases, the <i>L</i><sup>p</sup>-norms present a peculiar behaviour with certain threshold values of p, where the growth rate and the dominating intervals undergo a rapid change. The fourth paper analyzes a connection between probability and numerical analysis. More precisely, known estimates on the convergence rate of finite difference equations are "translated" into results on convergence rates of certain functionals in the central limit theorem. These are also extended, using interpolation of Banach spaces as a main tool. Besov spaces play a central role in the emerging results.</p>
|
Page generated in 0.1721 seconds