Le premier objectif de cette thèse consistait à tester l’existence de stratégies de raisonnements dans l’estimation de la probabilité diagnostique : P(cause|effet). A travers quatre expériences, nous montrons que l’estimation de cette probabilitépeut se réaliser selon deux voies formellement distinctes. La première consiste à évaluer P(cause|effet) à travers une forme de déduction affaiblie fondée sur un Modus Ponens rétractable (EFFET ; si EFFET alors il est probable que CAUSE ) il est probable que CAUSE). La seconde stratégie consiste à estimer la probabilité diagnostique à travers un raisonnement abductif qui correspond au schéma d’Affirmation du Conséquent probabilisé (EFFET ; si CAUSE alors il est probable que EFFET ) il est probable que CAUSE). Nous montrons que le choix de la stratégie est dépendant de la probabilité prédictive P(effet|cause) empirique présente dans les données. Quand cette probabilité est faible, les participants marquent une préférence pour la stratégie de type déduction rétractable, en revanche cette stratégie est fortement concurrencée par la stratégie abductive quand P(effet|cause) est haute. Le second objectif de cette recherche consistait à vérifier si les estimations des individus sous stratégie abductive d’une part, et sous stratégie d’estimation par Modus Ponens rétractable d’autre part, reflétaient fidèlement la probabilité diagnostique empirique. Les résultats d’une cinquième expérience infirment cette hypothèse. Quelle que soit la stratégie suivie, la probabilité diagnostique est systématiquement sous-estimée par les individus. Nos résultats indiquent toutefois que la stratégie par déduction rétractable permet d’aboutir à des estimations plus proches de la probabilité empirique. / The first goal of this thesis was to test the existence of reasoning strategies in the diagnostic probability estimate : P(cause|effect). Using four experiments, we show that the estimation of this probability can be achieved according to two formally distinct ways. The first consists in assessing P(cause|effect) through a weakened form of deduction based on a retractable Modus Ponens (EFFECT; if EFFECT then it is likely that CAUSE ) it is likely that CAUSE). The second strategy consists in estimating the diagnostic probability through abductive reasoning corresponding to the Affirmation of the Consequent probability scheme (EFFECT ; if CAUSE then it is likely that EFFECT ) it is likely that CAUSE). We show that the choice of strategy is dependent on the empirical predictive probability P(effect|cause) in the data. When this probability is low,participants show a preference for the retractable deduction strategy; On the other hand this strategy is strongly challenged by the abductive strategy when P(effect|cause) is high. The second objective of this research was to verify whether the estimates of people under abductive strategy on the one hand, and under defeasible Modus Ponens strategy on the other hand, accurately reflected the empirical diagnostic probability. The results of a fifth experiment invalidate this hypothesis. Regardless of the strategy followed, the diagnostic probability is systematically underestimated by people. Our results indicate, however, that the retractable deduction strategy provides estimates which come closer to the empirical probability

Ce mémoire présente le résultat de mon travail de thèse sur la génération d'impliqués premiers en logique équationnelle fermée, i.e., la génération des conséquences les plus générales de formules logiques contenants des équations et des disequations entre termes sans variables. Ce mémoire est divisé en trois parties. Tout d'abord, deux calculs de génération d'impliqués sont définis. Leur complétude pour la déduction est prouvée, ce qui signifie qu'ils sont tous deux capables de générer l'ensemble des impliqués modulo redondance d'une formule équationnelle fermée. Dans une deuxième partie, une structure de données arborescente est proposée pour stocker les impliqués générés, accompagnée d'algorithmes pour déceler les redondances et couper les branches de l'arbre lorsque c'est nécessaire. Cette structure de données est adaptée aux différents types de clauses (avec et sans symboles de fonctions, avec et sans contraintes) ainsi qu'aux différentes notions de redondance utilisées dans les calculs. En effet, chaque calcul utilise un critère de redondance légèrement différent des autres. Les preuves de correction et de terminaison des algorithmes sont fournies pour chaque algorithme. Enfin, une évaluation expérimentale des différentes méthodes de génération d'impliqués premiers est réalisée. Pour cela, un prototype de ces méthodes, écrit en Ocaml est comparé à des outils de génération d'impliqués premiers récents.Les résultats de ces expériences sont utilisés pour identifier les variantes les plus efficaces des algorithmes proposés. Les résultats sont prometteurs et dans la plupart des cas, meilleurs que ceux de l'état de l'art. / The work presented in this memoir deals with the generation of prime implicates in ground equational logic, i.e., of the most general consequences of formulae containing equations and disequations between ground terms.It is divided in three parts. First, two calculi that generate implicates are defined. Their deductive-completeness is proved, meaning they can both generate all the implicates up to redundancy of equational formulae.Second, a tree data structure to store the generated implicates is proposed along with algorithms to detect redundancies and prune the branches of the tree accordingly. This data structure is adapted to the different kinds of clauses (with and without function symbols, with and without constraints) and to the various formal definitions of redundancy used in the calculi since each calculus uses different -- although similar -- redundancy criteria. Termination and correction proofs are provided with each algorithm. Finally, an experimental evaluation of the different prime implicate generation methods based on research prototypes written in Ocaml is conducted including a comparison with state-of-the-art prime implicate generation tools. This experimental study is used to identify the most efficient variants of the proposed algorithms. These show promising results overstepping the state of the art.

Magister Legum - LLM

Trata-se de uma proposta de investigação das ideias cosmológicas de Charles S. Peirce, particularmente das que dizem respeito à pertinência da inclusão de esquemas de explicação que façam uso da causalidade final como instância determinante do desenvolvimento dos fenômenos naturais. Anterior à avaliação desse tipo de explicação cabe uma investigação sobre as características mais relevantes de seu pensamento, que o próprio autor julgava construído arquitetonicamente. Com esse objetivo, centramos a análise no conceito de continuum, que pode ser visto como fundamental para o desenvolvimento da obra de Peirce. É o estudo do continuum que permitirá e conduzirá a investigação das categorias ontológicas peirceanas: acaso, existente e lei. A passagem do acaso à lei, isto é, a própria origem do cosmos, se dá por um processo evolutivo que tem na lei da mente seu principal motor. A lei da mente, por sua vez, atua de modo finalístico, tornando mais provável o desenvolvimento dos fenômenos em certas direções, restringindo, assim, o horizonte das possibilidades, sem, contudo, esgotá-lo. / This thesis is about the cosmological ideas of Charles S. Peirce, particularly those concerning the relevance of the inclusion of explanatory schemes that make use of final causality as an instance determinant of the development of natural phenomena. Before the evaluation of this type of explanation, it is important to perform an investigation into the most relevant features of his thought, which the author believed was architecturally built. With this aim, we focus on the concept of the continuum, which can be seen as fundamental to the development of the work of Peirce. It is the study of the continuum that will lead to investigation of Peirce\'s ontological categories: chance, existent and law. The passage of chance to law, that is, the very origin of the cosmos, is given by an evolutionary process in which the law of the mind is its main engine. The law of the mind, in turn, acts in a finalistic way, making more probable the development of phenomena in certain directions, thus restricting the horizon of possibilities, without, however, exhausting it.

O Realismo Científico tem sido defendido quase exclusivamente através do Argumento do Milagre, segundo o qual ou assumimos que as teorias científicas são verdadeiras ou tornamos o sucesso da atividade científica em um fenômeno misterioso e inexplicável. No primeiro momento, as principais críticas ao argumento do milagre são reunidas em cinco objeções: (i) apresenta-se uma explicação alternativa para o sucesso da ciência que não assuma a verdade das teorias científicas e que compita com a explicação realista; (ii) defende-se que a hipótese realista não é uma explicação satisfatória para o sucesso da ciência, acusando-a de vacuidade explicativa, ou (iii) acusando-a de não satisfazer os critérios de rigor metodológico científico que ela mesmo impõe à justificação de teorias; (iv) afirma-se que o argumento seja uma petição de princípio, por pressupor uma regra de inferência abdutiva aceita apenas pela posição realista; (v) propõe-se que o argumento constitua uma falácia estatística ao ignorar um índice de fundo relevante. Ao replicar às objeções apresentadas, alguns autores propõem distinguir entre uma versão semântica do argumento, baseada no sucesso empírico obtido pelas teorias científicas enquanto entidades semânticas; e uma versão metodológica do argumento, baseada no sucesso pragmático dos cientistas em escolher teorias férteis e descobrir teorias bem sucedidas. Além disso, outros autores propõem uma segunda distinção entre uma versão geral do argumento, baseada estatisticamente no sucesso generalizado das teorias científicas, e uma versão retalhada do argumento, baseada na sua aplicação específica a uma teoria tomada individualmente. Após comparar as vantagens e desvantagens de cada interpretação, critica-se a relevância das distinções propostas e defende-se uma versão do argumento que sintetize suas diferentes interpretações de modo a solucionar as objeções inicialmente apresentadas. / Scientific Realism has been defended almost exclusively by the Non-Miracle Argument, which states that either it‘s assumed that scientific theories are true or the success of the scientific enterprise becomes a mysterious and unexplainable fact. At first, the main criticisms of the Non-Miracle Argument are gathered in five objections: (i) it‘s presented an alternative explanation to the success of science that competes with the realist explanation and does not assume the truth of the scientific theories; (ii) it‘s defended that the realist hypothesis is not a satisfactory explanation to the success of science, charging it of being an empty explanation, or (iii) charging its capacities to reach the scientific methodological rigorousness that itself imposes to the warrant of theories; (iv) it‘s affirmed that the argument is a petition principii, on account of presupposing an abductive rule of inference accepted only by the realist perspective; (v) it‘s proposed that the argument constitutes a statistical fallacy on account of neglecting a relevant base rate; When replying to the presented objections, some authors come up with the distinction between a semantic version of the argument, based on the empiric success reached by scientific theories considered as semantic entities, and a methodological version of the argument, based on the pragmatic success of scientists at choosing fruitful theories and discovering succeeded theories. Furthermore, other authors offer a second distinction between a general version of the argument, statistically based on the generalized success of science, and a retail version of the argument, based on its specific application to an individual theory. After comparing the advantages and drawbacks of each interpretation, the relevance of each distinction is reanalyzed and a new version of the argument by making a synthesis of its different interpretations is defended in a way to answer the five initial objections.

In this dissertation I consider the problem of external world skepticism and attempts at providing an argument to the best explanation against it. In chapter one I consider several different ways of formulating the crucial skeptical argument, settling on an argument that centers on the question of whether we're justified in believing propositions about the external world. I then consider and reject several options for getting around this issue which I take to be inadequate. I finally conclude that the best option available to us at the moment is to argue that the antiskeptical view is the best explanation of our ordinary experiences In chapter two I argue that, if we hope to ground what counts as defending antiskepticism in common sense, there is an argument against the possibility of ever knowing one has succeeded in defending antiskepticism. After showing that common sense is no place to look in setting a goal for our antiskeptical project, I present the view that what will be crucial to settling on our antiskeptical goal is coming to a successful analysis of the nature of physical objects. I suggest some minimal criteria that must be met by a view in order to be antiskeptical based on our intuitions about core skeptical cases, but acknowledge that a fully successful response to external world skepticism will require the antiskeptic to engage in some much more difficult analysis. In chapter three I consider various views of the nature of explanation and conclude, tentatively, that explanation as it interests the antiskeptic is fundamentally causal. In chapter four I consider and reject some of the core views on which best explanation facts are so fundamental that a project of attempting to vindicate probabilistically the virtues which make explanations epistemically good. In this chapter I show that views which analyze justification in terms of best explanation factors fail. In chapter five I attempt to vindicate the various explanatory virtues probabilistically. In doing so I attempt to express or translate the various explanatory virtues in terms of probabilities in order to show that having those virtues makes a view at least prima facie more probable. In chapters six and seven I explain and evaluate the various arguments to the best explanation against skepticism present in current philosophical literature. I attempt to show that extant arguments fail to appreciate the virtues possessed by classical (and some new) skeptical scenarios. In chapter eight I briefly consider some options that may be open to the antiskeptic moving forward. All routes forward contain considerable obstacles, but there are some fruitful areas of research to pursue.

Th. de licence et de doct.--Droit--Lausanne--Faculté de droit de l'Université de Lausanne. / Bibliogr. p. 515-522. Glossaire.

Dancers spend many years practicing repetitive movements in order for their bodies to gain flexibility, strength and muscle memory. This thesis investigated the biomechanics of a dance student's knee motion during a tendu to the front in first, third, and fifth positions. A dancer will often perform 75 or more tendu closing actions during one technique class - particularly in ballet technique. During a tendu the moving foot moves along the floor but the toes never leave the floor. The tendu is used to strengthen the leg muscles, particularly the quadriceps and gluteal muscles. Flexion/extension, abduction/adduction, and rotation angles of the knees during a traditional flat footed closing were compared to the knee angles during pli#233; and relev#233; closing. These movements were performed by 10 healthy dance students from USF. The dancers' movements were tracked using the VICON Nexus motion analysis system and 27 passive reflective markers placed on bony landmarks. Visual 3D software was used to calculate the knee angles. There were statistically significant the differences between knee angles during the traditional and pli#233; closings and between the relev#233; and pli#233; closings for all positions. There were only 4 conditions in which there was statistical significance between traditional and relev#233; closings. Knee flexion difference between the traditional and relev#233; closings was unanticipated, as the expectation of the tendu movement is to maintain a fully straight knee throughout the full range. This result suggests that the students may be bending the knees to achieve greater outward rotation, particularly in the third and fifth positions. The pli#233; had the largest range of motion (ROM) for all of the angles tested including abduction/adduction in which the subjects used the abduction at the knee to hold the feet in a turned out position. The collected data gives better insight into the biomechanics of the knee movement and will be used as feedback for improving muscular strength and preventing injuries in dancers.

This study is intended to address the problem of international parental child abduction from Islamic and international perspectives.  During a decade of working as a judge in the state of Qatar a number of cross-border child abduction cases occurred involving GCC, Arab and Western parents.  In none of these cases has the Hague Convention on The Civil Aspects of International Child Abduction (1980) been consulted or mentioned.  There is no evidence that the attention of Qatari judges has ever been drawn to the existence of this important international treaty. However, for the reasons given throughout this study, it will be argued that The Hague Convention is too important to be totally ignored by Muslim countries, while these countries will probably start to face an increasing number of cross-border child abduction cases.  The benefits of acceding to the Convention are made clear by considering a diversity of international cases where the solutions of the Convention best serve the welfare of the abducted children by procedurally ordering their prompt return to their habitual residence, thus putting to an end an arbitrary act of abduction unjustifiably carried out by one of the carers.  It is hoped that in the end this research will bring Islamic and Convention understandings closer to each other with regard to the problem of international parental child abduction.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Supervisor: Kathleen Stewart. Vita. Includes bibliographical references.