Représentation et combinaison d'informations incertaines : nouveaux résultats avec applications aux études de sûreté nucléaires

It often happens that the value of some parameters or variables of a system are imperfectly known, either because of the variability of the modelled phenomena, or because the availableinformation is imprecise or incomplete. Classical probability theory is usually used to treat these uncertainties. However, recent years have witnessed the appearance of arguments pointing to the conclusion that classical probabilities are inadequate to handle imprecise or incomplete information. Other frameworks have thus been proposed to address this problem: the three main are probability sets, random sets and possibility theory. There are many open questions concerning uncertainty treatment within these frameworks. More precisely, it is necessary to build bridges between these three frameworks to advance toward a unified handlingof uncertainty. Also, there is a need of practical methods to treat information, as using these framerowks can be computationally costly. In this work, we propose some answers to these two needs for a set of commonly encountered problems. In particular, we focus on the problems of:- Uncertainty representation- Fusion and evluation of multiple source information- Independence modellingThe aim being to give tools (both of theoretical and practical nature) to treat uncertainty. Some tools are then applied to some problems related to nuclear safety issues.Souvent, les valeurs de certains paramètres ou variables d'un système ne sont connues que de façon imparfaite, soit du fait de la variabilité des phénomènes physiques que l'on cherche à représenter,soit parce que l'information dont on dispose est imprécise, incomplète ou pas complètement fiable.Usuellement, cette incertitude est traitée par la théorie classique des probabilités. Cependant, ces dernières années ont vu apparaître des arguments indiquant que les probabilités classiques sont inadéquates lorsqu'il faut représenter l'imprécision présente dans l'information. Des cadres complémentaires aux probabilités classiques ont donc été proposés pour remédier à ce problème : il s'agit, principalement, des ensembles de probabilités, des ensembles aléatoires et des possibilités. Beaucoup de questions concernant le traitement des incertitudes dans ces trois cadres restent ouvertes. En particulier, il est nécessaire d'unifier ces approches et de comprendre les liens existants entre elles, et de proposer des méthodes de traitement permettant d'utiliser ces approches parfois cher en temps de calcul. Dans ce travail, nous nous proposons d'apporter des réponses à ces deux besoins pour une série de problème de traitement de l'incertain rencontré en analyse de sûreté. En particulier, nous nous concentrons sur les problèmes suivants :- Représentation des incertitudes- Fusion/évaluation de données venant de sources multiples- Modélisation de l'indépendanceL'objectif étant de fournir des outils, à la fois théoriques et pratiques, de traitement d'incertitude. Certains de ces outils sont ensuite appliqués à des problèmes rencontrés en sûreté nucléaire

On the Everettian epistemic problem

Recent work in the Everett interpretation has suggested that the problem of probability can be solved by understanding probability in terms of rationality. However, there are *two* problems relating to probability in Everett --- one practical, the other epistemic --- and the rationality-based program *directly* addresses only the practical problem. One might therefore worry that the problem of probability is only `half solved' by this approach. This paper aims to dispel that worry: a solution to the epistemic problem follows from the rationality-based solution to the practical problem

Universality caused: the case of renormalization group explanation

Recently, many have argued that there are certain kinds of abstract mathematical explanations that are noncausal. In particular, the irrelevancy approach suggests that abstracting away irrelevant causal details can leave us with a noncausal explanation. In this paper, I argue that the common example of Renormalization Group explanations of universality used to motivate the irrelevancy approach deserves more critical attention. I argue that the reasons given by those who hold up RG as noncausal do not stand up to critical scrutiny. As a result, the irrelevancy approach and the line between casual and noncausal explanation deserves more scrutiny

Inconceivable Minds

The current debate over the metaphysical nature of the mind is dominated by two major philosophical views: property dualism and physicalism. According to property dualism, mental properties are of metaphysically distinct types. There are phenomenal properties, or qualia, the properties that constitute conscious experience, and there are the cognitive or functional properties of the mind. According to physicalism, there is one metaphysical type of mental property, though there may be a deep conceptual divide between experience and cognition. I challenge both these assumptions. Focusing on two of the most popular anti-physicalist arguments- the Conceivability Argument and the Knowledge Argument- I argue that the property dualist's account of the relationship between consciousness and behavior- the explanatory irrelevance of consciousness to sufficient explanations our behavior and how we make judgment about our conscious experience- make the first argument untenable and the second irrelevant to the metaphysical debate. I also present a case against a physicalist conceptual separation between cognition and consciousness by challenging the Phenomenal Concept Strategy, the most popular argument supporting such a separation. This conceptual separation supposedly allows us to conceive of philosophical zombies, creature physically identical to human beings but who lack conscious experience. The phenomenal concept strategy aims to explain how we can conceive of zombies while maintaining a physicalist account of the metaphysics of mind. For this strategy to succeed, the physicalist must show that we share our epistemic situation regarding consciousness with our zombie-twins. Zombies make claims about their own phenomenal experience, just as we do, but by definition they have none. I examine the most common physicalist interpretation of the zombies' beliefs about their own conscious experiences and show that this leads to the creation of inconceivable minds- creatures whose mental features would be incompatible with the very interpretation of zombie phenomenal belief on which this strategy is based. My dissertation has two overarching goals. First, to undermine the plausibility of the two most popular arguments for property dualism, and second, to force physicalists to reconsider both the phenomenal concept strategy and their commitment to the genuine conceivability of zombies.Doctor of Philosoph