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Business Intelligence (BI) applications are consulted by their users on a daily basis. BI information obtained assist users to make business decisions and allow for a deeper understanding of the business and its driving forces. In a mining environment companies need to derive maximum benefit from BI applications, therefore these applications need to be used optimally. Optimal use depends on various factors including the usability of the product. The documented lack of usability evaluation guidelines provides the rationale for this study. The purpose is to investigate the usability evaluation of BI applications in the context of a coal mining organization. The research is guided by the question: What guidelines should be used to evaluate the usability of BI applications. The research design included the identification of BI usability issues based on the observation of BI users at the coal mining organization. The usability criteria extracted from the usability issues were compared and then merged with general usability criteria from literature to form an initial set of BI usability evaluation criteria. These criteria were used as the basis for a heuristic evaluation of the BI application used at the coal mining organization. The same application was also evaluated using the Software Usability Measurement Inventory (SUMI) standardised questionnaire. The results from the two evaluations were triangulated to provide a refined set of criteria. The main contribution of the study is the heuristic evaluation guidelines for BI applications (based on these criteria). These guidelines are grouped in the following functional areas: visibility, flexibility, cognition, application behaviour, error control and help, affect and BI elements. / Information Science / M.Sc. (Information Systems)

Nowadays the information system of dynamically developing companies has an increasingly important role. The aim of this thesis is to evaluate current information system used in Brněnské komunikace a.s., analyze its drawbacks and weak spots and then propose steps leading to its improvement and thus to increase the company´s performance.

Ce manuscrit porte sur la modélisation et la simulation numérique d’écoulements diphasiques compressibles. Dans ce contexte, les méthodes d’interfaces diffuses sont aujourd’hui bien acceptées. Cependant, un progrès est encore attendu en ce qui concerne la précision de la capture numérique de ces interfaces. Une nouvelle méthode est développée et permet de réduire significativement cette zone de capture. Cette méthode se place dans le contexte des méthodes numériques de type “MUSCL”, très employées dans les codes de production, et sur maillages non-structurés. Ces interfaces pouvant être le lieu où une transition de phase s’opère, celle-ci est considérée au travers d’un processus de relaxation des énergies libres de Gibbs. Un nouveau solveur de relaxation à thermodynamique rapide est développé et s’avère précis, rapide et robuste y compris lors du passage vers les limites monophasiques. En outre, par rapport aux applications industrielles envisagées, une extension de la thermodynamique des phases et du mélange est nécessaire. Une nouvelle équation d’état est développée en conséquence. La formulation est convexe et est basée sur l’équation d’état “Noble-Abel-Stiffened-Gas”. Enfin, sur un autre plan la dispersion de fluides non-miscibles sous l’effet de la gravité est également abordée. Cette problématique fait apparaître de larges échelles de temps et d’espace et motive le développement d’un nouveau modèle multi-fluide de type “shallow water bi-couche”. Sa résolution numérique est également traitée / This manuscript addresses the theoretical modeling and numerical simulation of compressible two-phase flows. In this context, diffuse interface methods are now well-accepted but progress is still needed at the level of numerical accuracy regarding their capture. A new method is developed in this research work, that allows significant sharpening. This method can be placed in the framework of MUSCL-type schemes, widely used in production codes and on unstructured grids. Phase transition is addressed as well through a relaxation process relying on Gibbs free energies. A new instantaneous relaxation solver is developed and happens to be accurate, fast and robust. Moreover, in view of the intended industrial applications, an extension of the thermodynamics of the phases and of the mixture is necessary. A new equation of state is consequently developed. The formulation is convex and based on the “Noble-Abel-Stiffened-Gas” equation of state. In another context, the dispersion of non-miscible fluids under gravity effects is considered as well. This problematic involves large time and space scales and has motivated the development of a new multi-fluid model for “two-layer shallow water” flows. Its numerical resolution is treated as well

Il existe des projections corticospinales (CS) vers les motoneurones (MNs) aussi bien contra- (c) qu’ipsilatérales (i). Les influences CSc sur les MNs du poignet sont connues pour être modulées entre autres par la position du poignet et les afférences cutanées. Pour cette raison, notre objectif était de vérifier si ces caractéristiques sont aussi valides pour les influences CSi. En utilisant la stimulation transcrânienne magnétique au niveau du cortex primaire droit, nous avons tout d’abord comparé les influences CSi sur les MNs des fléchisseurs du poignet à des positions maintenues de flexion et d’extension durant une tâche uni-manuelle ainsi que deux tâches bimanuelles, ceci chez des sujets droitiers (n=23). Nous avons ensuite comparé les influences CSi dans cinq tâches bi-manuelles de tenue d’objet durant lesquelles les sujets avaient à tenir entre leurs mains un bloc à la surface soit lisse, soit rugueuse, dont le poids était supporté ou non, ceci en position de flexion (n=21). Dans une tâche, un poids était ajouté au bloc lisse en condition non supportée pour amplifier les forces de préhension requises. Une modulation positiondépendante était observée au niveau des potentiels évoqués moteurs (iPEM), mais seulement lors de la tâche bi-manuelle quand les deux mains interagissaient via un bloc (p= 0.01). Une modulation basée sur la texture était également présente, quel que soit le support de poids, et le bloc lisse était associé avec des iPEMs plus importants en comparaison avec le bloc rugueux (p= 0.001). Ainsi, les influences CSi sur les MNs n’étaient modulées que lors des tâches bi-manuelles et dépendaient de la manière dont les mains interagissaient. De plus, les afférences cutanées modulaient les influences CSi facilitatrices et pourraient ainsi participer à la prise en main des objets. Il en est conclu que les hémisphères droit et gauche coopèrent durant les tâches bimanuelles impliquant la tenue d’objet entre les mains, avec la participation potentielle de projections mono-, et poly-synaptiques, transcallosales inclues. La possibilité de la contribution de reflexes cutanés et d’étirement (spinaux et transcorticaux) est discutée sur la base de la notion que tout mouvement découle du contrôle indirect, de la « référence » (referent control). Ces résultats pourraient être essentiels à la compréhension du rôle des interactions interhémisphériques chez les sujets sains et cliniques. / There are both contra- (c) and ipsilateral (i) corticospinal (CS) projections to motoneurons (MNs). There is evidence that cCS influences on wrist MNs are modulated by wrist position and cutaneous afferents. Thus, we aimed to test whether these findings are valid for iCS influences as well. Using transcranial magnetic stimulation applied over the right primary motor cortex, we first compared iCS influences on wrist flexor MNs at actively maintained flexion and extension wrist positions in one uni- and two bimanual tasks in right-handed subjects (n=23). We further compared iCS influences in five bimanual holding tasks in which subjects had to hold a smooth or coarse block between their hands, with or without its weight being supported, in flexion position (n=21). In one task, a weight was added to the unsupported smooth block to increase load forces. A position-dependent modulation of the short-latency motor evoked potential (iMEP) was observed, but only in the bimanual task when the two hands interacted through a block (p=0.01). A texture-dependent modulation was present regardless of the weight supported, and the smooth block was associated with larger iMEPs in comparison to the coarse block (p=0.001). Hence, iCS influences on MNs were modulated only in bimanual tasks and depended on how the two hands interacted. Furthermore, cutaneous afferents modulated facilitatory iCS influences and thus may participate to grip forces scaling and maintaining. It is concluded that the left and right cortices cooperate in bimanual tasks involving holding an object between the hands, with possible participation of mono- and poly-synaptic, including transcallosal projections to MNs. The possible involvement of spinal and trans-cortical stretch and cutaneous reflexes in bimanual tasks when holding an object is discussed based on the notion that indirect, referent control underlies motor actions. Results might be essential for the understanding of the role of intercortical interaction in healthy and neurological subjects.

Multiculturalism and the merging of local communities with immigrants demands glocal policies in various sectors—especially in education. In order to successfully integrate immigrants, language acquisition is oftentimes the first initiative educators and politicians regard as one of the most essential attributes for successful and prompt integration. However, language acquisition cannot be separated from the need to bridge communities and their different values, tradition, ideologies, and identities based on their cultural heritages and religious affiliations. In order to properly respond to newly-emerging glocal dynamics in, for instance, classrooms, it is crucial to understand the shifts in racisms from black versus white to East versus West. Therefore, concepts need to consider different dynamics and embrace issues related to gender, sexuality, skin color, habitus, social, financial, and cultural capital, as well as educational achievement (gaps) on an interdisciplinary level. While seeking to find appropriate adaptations of school curricula, it is necessary to not try to run before one can walk—in other words—to not try to let educators teach before they have been taught cross-cultural communication. In addition, racisms cannot be limited to conflicts between immigrants and non-immigrants; racisms also occur among a homogeneous group. The complexity of reuniting and/or integrating various immigrant, non-immigrant, (Middle) Eastern and Western identities and their (intercultural) belonging is critical because of the various circumstances and settings that need to be considered for responding to linguistic, cultural, social, psychological, educational, and financial matters individually. Although there is not one concrete theoretical framework or outcome that can be applied for integration; this dissertation thesis functions as a roadmap for becoming more aware of regional and international struggles. Despite the multifaceted approaches that need to be combined and implemented in terms of second language acquisition, updated teacher training, cross-cultural policies, access to social services and support systems, etc., the education sector remains the foundation for prospective integration: Integrative and multiculturally-aware education provides the glocal society with intercultural and interdisciplinary-applicable assets and capitals. Such abilities help create a politically, socially, financially, culturally, and educationally responsible future embracing transatlantic intermingling instead of oppressing Otherness. Local and global communities benefit from better-adjusted and well-integrated immigrant families and students. The better societies and politics educate, integrate, and value non-locals, the more societies will benefit culturally, socially, politically, and economically from the glocal population. The newly-introduced PIC SAM guidelines provide, in cooperation with key actors and community-centered programs for immigrants and non-immigrants, a roadmap for combining theory and practice in glocal contexts.:Table of Contents vi List of Figures, Tables, and Illustrations x Chapter One 1 Personal Narrative and Relevance: Education as Powerful Integration Tool 1 Rationale, Overview, and Global Integration and Education 7 Theoretical Framework and Methodological Approaches 14 Terminology 17 Steps for Globally-Adjusted Integration and Education 29 Step 1: Understanding Legal Challenges of Turkish Immigrants 29 Step 2: Understanding that Not Every Middle Easterner is a Muslim 33 Step 3: Starting Successful Integration in Kindergarten 33 Step 4: Nurturing Integration Instead of Oppressing Immigration 36 Step 5: Adapting CRT—From Colorblind to Headscarfblind 39 Step 6: Taking the Education Exit for Integration 43 Step 7: Taking the Education Exit to Integration 44 Step 8: Sprucing Up the Headscarf Image 45 Chapter Two 48 Literature Review 48 Chapter Three 103 “Other” Ideologies and Identities—Theoretical Approaches 103 (1) How to Approach Different Ideologies 103 (2) Reasons for Othering and Biased Headscarf Images 103 (3) Disempowering the Exotic Other 104 (4) The Danger of Ill-Ideologies 106 (5) Ideologies as Utopia and Fantasy 108 (6) Capitalization and Mass Economization of Identities and Ideologies 109 (7) Institutionalization of the ISA (aka the School) 110 Chapter Four 113 Individuals are Always-Already Subjects of Ideology 113 Concepts Creating the Multifaceted Constructions of Ideology 114 (1) Ideology as A-Historical 114 (2) Is Ideology “Real” or an Illusion? 115 (3) Individuals are Always-Already Subjects (of Ideology) 116 (4) Subjects within a Mass-Produced Media (Ill)Ideology 117 (5) Shift: From Dominant via Repressed Ideology to State Apparatus 119 (6) Concluding Thoughts on Ideologies 120 Chapter Five 123 Race as Product of Social, Political, and Educational Thought 123 Chapter Six 128 Shifts in Racisms: Whitewashed—From Black to (Middle) East 128 The Wende within Immigration and Globalization 134 (1) History and Its Effect on Pre- and Post-Activism 134 (2) GDR Museums—(False?) Nostalgia in Times of Globalization 141 (3) Cross-Generational Racisms and Racialized White Others 145 Chapter Seven 149 Different Social and Cultural Capitals: East vs. West (German) Habitus 149 Adapting Bourdieu’s Habitus to Different Contexts 151 Comparative Examples: Disadvantaged Groups in the Education Sector 154 Getting to the Nitty-Gritty: The Case of Oscar 156 Concluding the Nitty-Gritty: Political Trust and Progressive Educators 165 Chapter Eight 170 Reverse Activisms: The Importance of Transnational Post-Activism 170 Tear Down that Church! 173 Transferring Activism from the GDR to the 21st Century 177 From “Teaching” Activism to “Doing” Activism 181 East versus West: Striving for Balanced Activisms 184 Activism, Aktivismus, and Activisme—or Negativism? 187 Chapter Nine 190 Adapting and Diversifying CRT 190 Teaching and Learning German and Intercultural Communication 195 Global and Anti-Racist Pedagogies In- and Outside of Schools 200 Roadmap for Changing (the) Dynamics in Germany’s Education 203 (1) Cross-Language Policies: Bilingualism for Everyone 203 (2) Current Challenges in Germany’s Education System 207 (3) Key Actors and Levels in Addressing the Integration Problem(s) 208 (4) Solution Approaches 210 Chapter Ten 212 Glocal Frameworks: Adding “Bi-Religionism” to Bilingualism & Biculturalism 212 Getting to the Nitty-Gritty: The Case of Mo 215 Educational Policy Recommendations 224 Concluding the Nitty-Gritty 230 Chapter Eleven 233 Outlook and Conclusion: Striving for Glocal Awareness and Activist Change 233 References 243 Endnotes 263

Abstract Between October 1999 and October 2003, 30 adult and 48 young (< 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young racoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radio-collared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.

Between October 1999 and October 2003, 30 adult and 48 young (< 1 year) raccoon dogs (Nyctereutes procyonoides) were monitored using radio-telemetry in an area of North-East Germany which has been occupied by this invasive alien species since the early 1990s. Additionally, three pairs of raccoon dogs were observed by continuous radio-tracking during the first six weeks after parturition in 2003. Furthermore 136 raccoon dog pubs were ear-tagged between June 1999 and August 2006. No adult animals dispersed from the area during the study period and home ranges tended to be used for several years, probably for life. The average annual home range size, calculated using 95% fixed kernel, was 382.2 ha ± 297.4 SD for females (n = 30 seasonal home ranges) and 352.4 ha ± 313.3 SD for males (n = 32 seasonal home ranges). Paired raccoon dogs had home ranges of similar size, with pair mates sharing the same area all year round. Raccoon dogs occupied large core areas (85% kernel) covering 81.2% of their home ranges. The home ranges were at their smallest during the mating season. The slightly larger size of home ranges in winter suggests that, due to the temperate climate, raccoon dogs do not hibernate in Germany. Males and females formed a long-term (probably lifelong) pair bond. Same-sex neighbours ignored each other and even adjacent males/females showed neither preference nor avoidance. Thus, it can be assumed that the raccoon dog in Central Europe is monogamous without exclusive territories, based on the results of home range overlap analysis and interaction estimations. Habitat composition within home ranges and within the whole study area was almost equal. Although, percentage shares of farmland and meadow was 16.35% smaller and 12.06% higher within the home ranges, respectively. All nine habitat types (farmland, forest, settlement, water, meadows, maize fields, small woods, reeds and hedges) were used opportunistically by raccoon dogs. No significant, recognisable difference for habitat preferences between seasons was detected. Male and female raccoon dog showed equal habitat preference pattern. A comparison of active and inactive locations in different habitats found no remarkable differences. Habitat composition of individual home ranges was used to classify animals. If the percentage of forest within a home range exceeded 50% the individual was classified as a ‘forest type’ raccoon dog. If the percentage of forest habitats within a home range was less than 5%, the share of pastureland was mean 81.82% ± 16.92 SD. Consequently the individual was classified as a ‘agrarian type’ raccoon dog. Neither habitat preference nor habitat selection process differed between the two ‘types’. Habitat use and preference is discussed with relation to the ability of the raccoon dog to expand its range towards Western Europe. Males spent noticeably more time (40.5% of the time ±11.7 SD) alone with the pups than females (16.4% of the time ±8.5 SD). Females had noticeably larger 95% kernel home ranges (98.24 ha ±51.71 SD) than males (14.73 ha ±8.16 SD) and moved much longer daily distances (7,368 m ±2,015 SD) than males (4,094 m ±2,886 SD) in six weeks postpartum. The raccoon dogs being studied left the breeding den in the 6th week after the birth of the pups. In situ video observation showed that the male carried prey to the den to provide the female and the litter with food. A clear division of labour took place among parents during the period in which the pups were nursed: males guarded the litter in the den or in close vicinity of it, while the females foraged to satisfy their increased energy requirements. There were relocations of 59 (43.4%) ear-tagged young raccoon dogs and mean distance from marking point was 13.5 km ±20.1 SD. Dispersal mortality rate was 69.5% among young raccoon dogs. Most animals (55.9%) were recovered nearer than 5 km from the marking point, whereas only 8.5% relocations were recorded further than 50 km from the marking point. There was no difference in the distances of relocations between sexes. Most (53.7%) relocations of ear-tagged young raccoon dogs were in August and September and, only 34.1% were recorded from October to April. Hunting (55 %) and traffic (27 %) were the major mortality factors. Radiocollared young raccoon dogs generally dispersed between July and September. The mean natal home range size (MCP 100%) with and without excursions was 502.6 ha ±66.4 SD (n = 9) and 92.1 ha ±66.4 SD (n = 17), respectively. There were no differences between sexes in the month of dispersal. The direction of travel for dispersing animals appeared to be random, with distances from 0.5 km to 91.2 km. A highly flexible dispersing behaviour is certainly one of the reasons which contribute to the high expansion success of the species.

<div><div><div><p>The process of acquiring the large-scale complex systems is usually characterized with cost and schedule overruns. To investigate the causes of this problem, we may view the acquisition of a complex system in several different time scales. At finer time scales, one may study different stages of the acquisition process from the intricate details of the entire systems engineering process to communication between design teams to how individual designers solve problems. At the largest time scale one may consider the acquisition process as series of actions which are, request for bids, bidding and auctioning, contracting, and finally building and deploying the system, without resolving the fine details that occur within each step. In this work, we study the acquisition processes in multiple scales. First, we develop a game-theoretic model for engineering of the systems in the building and deploying stage. We model the interactions among the systems and subsystem engineers as a principal-agent problem. We develop a one-shot shallow systems engineering process and obtain the optimum transfer functions that best incentivize the subsystem engineers to maximize the expected system-level utility. The core of the principal-agent model is the quality function which maps the effort of the agent to the performance (quality) of the system. Therefore, we build the stochastic quality function by modeling the design process as a sequential decision-making problem. Second, we develop and evaluate a model of the acquisition process that accounts for the strategic behavior of different parties. We cast our model in terms of government-funded projects and assume the following steps. First, the government publishes a request for bids. Then, private firms offer their proposals in a bidding process and the winner bidder enters in a con- tract with the government. The contract describes the system requirements and the corresponding monetary transfers for meeting them. The winner firm devotes effort to deliver a system that fulfills the requirements. This can be assumed as a game that the government plays with the bidder firms. We study how different parameters in the acquisition procedure affect the bidders’ behaviors and therefore, the utility of the government. Using reinforcement learning, we seek to learn the optimal policies of involved actors in this game. In particular, we study how the requirements, contract types such as cost-plus and incentive-based contracts, number of bidders, problem complexity, etc., affect the acquisition procedure. Furthermore, we study the bidding strategy of the private firms and how the contract types affect their strategic behavior.</p></div></div></div>

Nombreux sont ceux à considérer que depuis le développement de la médecine curative, la prévention a occupé une place secondaire dans le système de santé français. La préoccupation majeure aurait été jusque-là d’assurer un accès aux soins plutôt que de favoriser une culture de la prévention. Depuis quelques années, les différents drames sanitaires (transfusion sanguine, amiante, canicule, hormone de croissance, épidémies de grippe, cancers,...) ont sensibilisé l’opinion à la notion de “sécurité sanitaire” et fait émerger une prise de conscience nouvelle autour des problématiques de la prévention. Le recours à la prévention permet aux individus et aux pouvoirs publics d’exercer un contrôle sur les risques de santé auxquels ils sont exposés et de mener des actions conséquentes dans le but d’améliorer l’état de santé en évitant l’apparition, le développement ou l’aggravation des maladies ou des accidents tout en favorisant des comportements individuels et collectifs pouvant contribuer à réduire les risques sanitaires. Une des réponses face aux risques de santé est d’inciter les individus à plus de prévention car ils ne sont plus seulement consommateurs de soins mais aussi producteurs de leur état de santé. Quel est donc le rôle des individus et quelle est la part de responsabilité dévolue à chacun dans la prévention des risques sanitaires ? De plus, la prévention des risques sanitaires s’inscrit dans un environnement d’ambiguïté et d’incertitudes car les risques auxquels sont exposés les individus sont diversement nombreux et pas toujours bien connus. Il n’est donc pas aisé de relier avec certitude un facteur de risque et un effet sanitaire pour ainsi adopter un comportement de prévention adéquat. Dans ce contexte d’incertitude, de nombreux modèles d’aide à la décision, ou de représentations des préférences ont été proposés ces dernières années (Klibanoff et al.(2005), Bleichrodt et Eeckhoudt(2006) Machina(2009), Etner et al.(2011)). Cette thèse analyse les comportements de prévention des individus face à des risques de santé tout en mettant l’accent sur les politiques publiques de prévention proposées. Elle consiste d’une part à des études théoriques des comportements de prévention et de gestion des risques sanitaires en utilisant des modèles récents de préférences. Ce travail analyse le comportement des individus qui doivent prendre des mesures de prévention pour protéger leur propre santé dans un contexte d’incertitude. D’autre part, elle se consacre à une étude empirique pour cerner les perceptions et informations qu’ont les individus en termes de risque de santé. En outre, tout au long de ce travail, nous avons cherché à étudier la pertinence du modèle théorique élaboré au regard des politiques pratiquées. Le premier chapitre présente les principes de modélisation des décisions économiques en présence d’un risque de santé plus ou moins bien connu. Après avoir détaillé lesdifférentes approches dans les modèles de décisions dans le risque et dans l’incertain, nous avons mis en relief l’importance de l’introduction de variables bidimensionnelles (ou multidimensionnelles) dans le modèle de choix pour permettre de rendre de l’environnement multidimensionnel des risques de santé. Le deuxième chapitre est une étude originale proposée sur l’analyse de la prévention en santé lorsque les individus présentent de l’aversion à l’ambiguïté. Dans ce chapitre, nous avons étudié les comportements individuels de prévention face à une incertitude sur l’état de santé et avons montré que l’aversion à l’ambiguïté incite les individus à faire plus de prévention primaire et secondaire sous l’hypothèse d’une utilité marginale de la richesse croissante avec l’état de santé. (...) / Many are those to consider that since the development of the curative medicine, the prevention occupied a secondary place in the French health care system. Major concern would have been up to that point to ensure an access to healthcare rather than to support a culture of prevention. Since a few years, various medical dramas (blood transfusion, asbestos, heat wave, growth hormone, flu epidemics,cancers,...) have raised awareness of the concept of “safety” and brings out a new awakening around the prevention problems.The use of prevention allows the individuals and the public authorities to exert a control on the health risks to which they are exposed and to conduct consequent actions in order to improve health and prevent the emergence, the development, the development or the aggravation of the diseases or accidents while promoting individual and collective behaviors that can help to reduce the risk health. One of the answers in front of the health risks is to incite the individuals to more prevention because they are not only consumers of care, but also producers of their health. What is the role of individuals and what is the share of responsibility reserved for each one in the prevention of health risks ? In addition, the prevention of health risks is part of an environment ambiguity and uncertainty because the risks to which are exposed individuals are many different ways and not always well known. It is thus not easy to connect with certainty a risk factor and a health effect for adopting an adequate prevention behavior. In this context of uncertainty, many support the decision models or representations of preferences have been proposed in recent years (and Klibanoff (al. (2005), and Bleichrodt Eeckhoudt (2006), Machina 2009), Etner et al. (2011)).This thesis analyzes the individual behaviors of prevention in front of health risks while focusing on the public policies of prevention proposed. It consists on the one hand in theoretical studies of the behaviors of prevention and management of the health risks by using recent models of preferences. This work analyzes the behavior of the individuals who need to take preventive measures to protect their own health in a context of uncertainty. On the other hand, it is devoted to an empirical study to determine perceptions and information which have the individuals in terms of risk of health. Moreover, throughout this work, we sought to examine the relevance of the theoretical model developed with regard to the policies practiced. The first chapter presents the principles of modeling economic decisions in the presence of a more or less well known health risk. After detailing the different approaches in models of decisions under risk and uncertainty, we have highlighted the importance of the introduction of two-dimensional variables (or multidimensional) in the model of choice to allow to report the multidimensional environment of health risks. The second chapter is an original proposed study on the analysis of preventive health when the individuals have an aversion to ambiguity. In this chapter, we studied individual behavior of prevention in front of an uncertainty on the health status and have showed that aversion to ambiguity encourages the individuals to make more primary and secondary prevention under the assumption of a marginal utility of the increasing wealth with the health status. (...)