Les environnements virtuels permettent de représenter des personnes par des humains virtuels ou avatars. Le sentiment de présence virtuelle entre utilisateurs est renforcé lorsque l’avatar ressemble à la personne qu’il représente. L’avatar est alors classiquement un clone de l’utilisateur qui reproduit son apparence et sa voix. Toutefois, la possibilité de cloner l’expressivité des gestes d’une personne a reçu peu d’attention jusqu’ici. Expressivité gestuelle combine le style et l’humeur d’une personne. Des paramètres décrivant l’expressivité ont été proposés dans des travaux antérieurs pour animer les agents conversationnels. Dans ce travail, nous nous intéressons à l’expressivité des mouvements du poignet. Tout d’abord, nous proposons des algorithmes pour estimer trois paramètres d’expressivité à partir des trajectoires dans l’espace du poignet : la répétition, l’étendue spatiale et l’étendue temporelle. Puis, nous avons mené une étude perceptive sur la pertinence de l’expressivité des gestes pour reconnaître des personnes. Nous avons animé un agent virtuel en utilisant l’expressivité estimée de personnes réelles, et évalué si des utilisateurs peuvent reconnaître ces personnes à partir des animations. Nous avons constaté que des gestes répétitifs dans l’animation constituent une caractéristique discriminante pour reconnaître les personnes, tandis que l’absence de répétition est associée à des personnes qui répètent des gestes ou non. Plus important, nous avons trouvé que 75% ou plus des utilisateurs peuvent reconnaître une personne (parmi deux proposée) à partir d’animations virtuelles qui ne diffèrent que par leurs étendues spatiales et temporelles. L’expressivité gestuelle apparaît donc comme un nouvel indice pertinent pour le clonage d’une personne / Virtual environments allow human beings to be represented by virtual humans or avatars. Users can share a sense of virtual presence is the avatar looks like the real human it represents. This classically involves turning the avatar into a clone with the real human’s appearance and voice. However, the possibility of cloning the gesture expressivity of a real person has received little attention so far. Gesture expressivity combines the style and mood of a person. Expressivity parameters have been defined in earlier works for animating embodied conversational agents.In this work, we focus on expressivity in wrist motion. First, we propose algorithms to estimate three expressivity parameters from captured wrist 3D trajectories: repetition, spatial extent and temporal extent. Then, we conducted perceptual study through a user survey the relevance of expressivity for recognizing individual human. We have animated a virtual agent using the expressivity estimated from individual humans, and users have been asked whether they can recognize the individual human behind each animation. We found that, in case gestures are repeated in the animation, this is perceived by users as a discriminative feature to recognize humans, while the absence of repetition would be matched with any human, regardless whether they repeat gesture or not. More importantly, we found that 75 % or more of users could recognize the real human (out of two proposed) from an animated virtual avatar based only on the spatial and temporal extents. Consequently, gesture expressivity is a relevant clue for cloning. It can be used as another element in the development of a virtual clone that represents a person

Cancer is a serious family of disease that continues to cripple and claim those afflicted. For the last several decades, America has invested in a national program to alleviate cancer and cancer related suffering, ultimately seeking a cure. As part of this goal, the National Cancer Institute (NCI) has spent significant effort scouring the globe with the hope of finding naturally occurring compounds that can successfully combat cancer. Presently, this effort has uncovered many natural products with chemotherapeutic potential and many of the lead agents used in the fight against cancer are either natural products themselves or are compounds inspired by a natural product. This work describes one family of natural products uncovered by the NCI that is being explored for chemotherapeutic applications, namely the schweinfurthins. The schweinfurthins were isolated by the NCI; however the natural source, Macaranga schweinfurthii, did not provide these compounds in ample quantity to permit further study. The paucity of natural material indicated that a chemical synthesis of these compounds would be the most reliable method to provide meaningful amounts of schweinfurthins. The present work describes the chemical synthesis of four of the most potent schweinfurthins, describes the synthesis of numerous structural analogues, and details advances to the field of cascade cyclizations which makes their synthesis possible.

Le Conseil Général de la Gironde (CG33) est une collectivité territoriale qui met en oeuvre les politiques décidées par des élus. L’une de ses missions fondamentales est l’induction de comportements auprès des citoyens, des acteurs économiques et institutionnels. Citons par exemple la concrétisation, par l’intermédiaire de la réalisation de projets, des politiques publiques autour des thématiques du développement Durable (DD). Un constat issu des retours d’expérience s’impose : les projets mis en oeuvre au CG 33 sont de plus en plus complexes. Ils requièrent la collaboration de nombreux acteurs publics et privés qui se connaissent mal. Les démarches territoriales de DD nécessitent l’articulation de compétences spécifiques et interdépendantes, qui n’existent pas chez un acteur unique. Ces constats sont généralisables, quel que soit le secteur d’activité professionnelle. La connaissance, l’identification et le partage optimal de compétences est au coeur même de la réussite de projets. La problématique consiste à répondre aux attentes de tout maître d’oeuvre qui doit être capable de définir un projet, d’identifier les compétences qui le composent, les acteurs capables d’exercer ces compétences, puis finalement d’évaluer à postériori la réussite globale du projet. Définir la liste des compétences n’est pas toujours aisé puisqu’elles évoluent au fil du temps. Elles peuvent, par exemple, se transformer suite à l’arrivée d’évolutions techniques. Elles peuvent également disparaitre si elles sont remplacées ou bien finalement non utilisées. Un système optimal se doit donc d’être dynamique lors de la constitution des projets au fil du temps, dans le but de coller au plus prêt de la réalité du contexte dans lequel le système est utilisé. Nous voyons bien ici que la Compétence(et non l’acteur) est l’élément fondamental du système.Une réponse dite « classique » pourrait consister à réaliser simplement une base de données où les compétences et acteurs seraient des objets statiques. Cette solution ne répondant pas à notre souhait de dynamisme. Nous proposons plutôt un système informatique collaboratif, accessible en ligne, dans lequel nous définissions des « agents compétence » (AC), dynamiques et apprenants, qui évoluent au sein d’une architecture de type multi-agents. Chaque AC y est unique, bien qu’il puisse être incarné sur le terrain par plusieurs acteurs humains. Il possède une « vie propre », des moyens d'actions multiples et multi-localisés (réparti sur plusieurs acteurs physiques). Tout AC dispose de mécanismes de perception de son environnement, de communication avec les autres ACs. Il utilise de ressources (telles que les acteurs humains) et vise à réaliser 4buts principaux :1. Constituer sa propre définition (liste des compétences élémentaires) 2. Restituer une liste d’acteurs humains capables de le concrétiser sur le terrain3. Etablir des relations avec d’autres ACs afin d’optimiser la constitution des projets4. Se porter spontanément candidat à une participation à de nouveaux projets. Nos ACs ont également un « cycle de vie » décliné en 3 « âges » (enfance, adolescence et maturité). Chacun d’eux correspond à un niveau d’autonomie particulier. Notre SMA est de type «évènementiel ». Les agents y évoluent grâce aux interactions avec les194 utilisateurs humains du système. Un « modèle comportemental » dédié et évolutif est proposé dans le but d’optimiser leur dynamisme et de stimuler leur apprentissage. / In France, the “Conseil Général de la Gironde” is a local authority that promotes various sustainable development policies and practices. One of its missions is to coordinate and stimulate public and private partnerships in the framework of green building projects.Whatever the sector of professional activities and the thematic addressed, the concrete projects’ feedbacks show all the complexity to succeed in managing efficiently the collaboration of involved actors. Indeed, each of them has only a partial knowledge ofthe others’ skills. To answer to the problematic, and in order to improve the management of the projects, we propose an online collaborative tool that allows actors to share skills. According to the “Multi-Agent” theory, "skill agents" have been defined.The key idea is to consider that a skill is an agent of the system, and the actors are only its resources.Skill agents are dynamic and autonomous, have learning abilities, and have their ownlife cycle. They pursue four main goals: building their own definition, identifying actorswho can concretize them across projects, setting up links with other skill agents, and beeing candidates to new projects. Skill agents interact with human actors to stimulate their cooperation.This work shows that our model is appropriate for complex collaborative projects,giving results in various areas. For example, a case study based on the selection of players to form a rugby team has been given.

The recent emergence of intelligent agent technology and advances in information gathering have been the important steps forward in efficiently managing and using the vast amount of information now available on the Web to make informed decisions. There are, however, still many problems that need to be overcome in the information gathering research arena to enable the delivery of relevant information required by end users. Good decisions cannot be made without sufficient, timely, and correct information. Traditionally it is said that knowledge is power, however, nowadays sufficient, timely, and correct information is power. So gathering relevant information to meet user information needs is the crucial step for making good decisions. The ideal goal of information gathering is to obtain only the information that users need (no more and no less). However, the volume of information available, diversity formats of information, uncertainties of information, and distributed locations of information (e.g. World Wide Web) hinder the process of gathering the right information to meet the user needs. Specifically, two fundamental issues in regard to efficiency of information gathering are mismatch and overload. The mismatch means some information that meets user needs has not been gathered (or missed out), whereas, the overload means some gathered information is not what users need. Traditional information retrieval has been developed well in the past twenty years. The introduction of the Web has changed people's perceptions of information retrieval. Usually, the task of information retrieval is considered to have the function of leading the user to those documents that are relevant to his/her information needs. The similar function in information retrieval is to filter out the irrelevant documents (or called information filtering). Research into traditional information retrieval has provided many retrieval models and techniques to represent documents and queries. Nowadays, information is becoming highly distributed, and increasingly difficult to gather. On the other hand, people have found a lot of uncertainties that are contained in the user information needs. These motivate the need for research in agent-based information gathering. Agent-based information systems arise at this moment. In these kinds of systems, intelligent agents will get commitments from their users and act on the users behalf to gather the required information. They can easily retrieve the relevant information from highly distributed uncertain environments because of their merits of intelligent, autonomy and distribution. The current research for agent-based information gathering systems is divided into single agent gathering systems, and multi-agent gathering systems. In both research areas, there are still open problems to be solved so that agent-based information gathering systems can retrieve the uncertain information more effectively from the highly distributed environments. The aim of this thesis is to research the theoretical framework for intelligent agents to gather information from the Web. This research integrates the areas of information retrieval and intelligent agents. The specific research areas in this thesis are the development of an information filtering model for single agent systems, and the development of a dynamic belief model for information fusion for multi-agent systems. The research results are also supported by the construction of real information gathering agents (e.g., Job Agent) for the Internet to help users to gather useful information stored in Web sites. In such a framework, information gathering agents have abilities to describe (or learn) the user information needs, and act like users to retrieve, filter, and/or fuse the information. A rough set based information filtering model is developed to address the problem of overload. The new approach allows users to describe their information needs on user concept spaces rather than on document spaces, and it views a user information need as a rough set over the document space. The rough set decision theory is used to classify new documents into three regions: positive region, boundary region, and negative region. Two experiments are presented to verify this model, and it shows that the rough set based model provides an efficient approach to the overload problem. In this research, a dynamic belief model for information fusion in multi-agent environments is also developed. This model has a polynomial time complexity, and it has been proven that the fusion results are belief (mass) functions. By using this model, a collection fusion algorithm for information gathering agents is presented. The difficult problem for this research is the case where collections may be used by more than one agent. This algorithm, however, uses the technique of cooperation between agents, and provides a solution for this difficult problem in distributed information retrieval systems. This thesis presents the solutions to the theoretical problems in agent-based information gathering systems, including information filtering models, agent belief modeling, and collection fusions. It also presents solutions to some of the technical problems in agent-based information systems, such as document classification, the architecture for agent-based information gathering systems, and the decision in multiple agent environments. Such kinds of information gathering agents will gather relevant information from highly distributed uncertain environments.

Les cadres interactionnels actuels pour les communications entre agents (protocoles, stratégies de conversation, jeux de dialogue, ...) garantissent la cohérence structurelle des conversations tenues. Pourtant, ce n'est pas tant l'habilité des agents à structurer leurs conversations qui nous intéresse que leurs aptitudes à tenir des conversations utiles quant à leurs objectifs individuels et collectifs. Pour traiter cette problématique, nous avons défini et implanté un modèle complet de la communication entre agents qui couvre les quatre dimensions classiques de la communication : syntaxe, structure, sémantique et pragmatique. Au niveau syntaxique, nous proposons le langage DIAGAL[DIAlogue Game based Agent communication Language] qui se présente comme un ensemble de jeux de dialogue qui permettent la manipulation conjointe d'engagements sociaux. Du point de vue de la structuration des dialogues, les jeux de dialogue que nous proposons offrent une alternative à la rigidité des protocoles tout en capturant les aspects conventionnels de la communication, absents des approches considérant des actes de langages isolés. Dans notre approche, le niveau sémantique de la communication repose, quant à lui, sur les engagements sociaux qui capturent les interdépendances contractées par les agents lors des communications. Dans ce contexte, notre contribution principale concerne les aspects cognitifs de la pragmatique. À cet effet, nous proposons une théorie cognitive de l'utilisation de ce cadre interactionnel basée sur la notion de cohérence cognitive et fondée sur des résultats non encore formalisés de sciences cognitives. Issue d'une unification de la théorie de la dissonance cognitive (une des théories majeures de psychologie cognitive) avec la théorie de cohérence cognitive (développée en philosophie de l'esprit), notre approche est formulée en termes d'éléments et de contraintes, notions familières en informatique. La théorie motivationnelle résultante est ensuite étendue afin de traiter la communication entre agents cognitifs. Sous les hypothèses de notre théorie, nous définissons alors une métrique de l'utilité des conversations entre agents. Nous montrons comment cette théorie permet de résoudre en pratique de nombreux problèmes fondamentaux des aspects cognitifs de la pragmatique des communications entre agents. En particulier, nous proposons une première application de notre théorie pour l'utilisation automatique par des agents de type BDI [Beliefs, Desires and Intentions] des jeux de dialogue du langage DIAGAL. Ce faisant, nous introduisons un certain nombre d'outils techniques pour l'automatisation des communications entre agents tout en précisant quels sont nos apports théoriques pour les SMAs et plus généralement pour les sciences cognitives.

<p>This paper evaluates some arguments made against the conceptions of right action within virtue ethics. I argue that the different accounts of right action can meet the objections raised against them. Michael Slote‘s agent-based and Rosalind Hursthouses agent-focused account of right action give different judgments of right action but there seems to be a lack of real disagreement between the two accounts. I also argue that the concept of right action often has two important parts, relating to action guidance and moral appraisal, respectively, and that virtue ethics can deal with both without a concept of right action.</p>

Magnetic resonance imaging has developed into a powerful diagnostic technique characterized by a very high spatial resolution and an inherently relatively low sensitivity. In order to improve the contrast of MRI images, contrast agents are commonly injected into the patients before an examination. These substances are paramagnetic, superparamagnetic, or ferromagnetic compounds that shorten the relaxations times of the water hydrogen atoms. At present, most of the contrast enhanced clinical exams are performed with gadolinium complexes. They are particularly useful as their ability to change the relaxation rate (or relaxivity) can be very high. Several factors have a strong influence on the relaxivity of MRI contrast agents but the water exchange time τm and the rotational correlation time τr are particularly important for obtaining an increased relaxivity. These parameters can be adjusted by suitable chemical modifications of the Gd(III) complexes. For instance, decreasing the tumbling rate by linking a Gd(III) complex to a macromolecule leads to an increased relaxivity. This goal can be achieved through a covalent or a noncovalent linkage with synthetic polymers, particles or biomacromolecules. However, the covalent bonding has a detrimental effect on the clearance of the metal complexes thus exposing the patient to the toxicity of released Gd(III) ions and metabolites. This problem could be circumvented by using covalent links that are cleaved by endogenous biomolecules or after administration of exogenous compounds following the exam. In this context, our approach was to bind Gd(III) chelates to macromolecules through disulfide links as the latter are known to be reduced in vivo by thiols present in the body. Towards this aim, we have developed two bifunctional chelator agents bearing a methanethiosulfonate group (MTS) which reacts specifically with thiols, thus spontaneously establishing a disulfide bond between the Gd(III) chelate and the thiolated macromolecule. The first ligand that we have prepared (MTS-ADO3A) is a monoamide derivative of DOTA with an ethyl-MTS substituent. This compound is relatively easily synthesized but amide arms such as the one it features are known to have a detrimental effect on relaxivity through the lengthening of water exchange times. The conjugate obtained by binding Gd(III) chelates of this ligand to albumin or to polythiolated silica nanoparticles has been studied by nuclear magnetic relaxation dispersion (NMRD),17O NMR and luminescence analyses. These measurements confirm that the method is suitable to increase the relaxivity (20 mM-1s 1, 20 MHz, 25°C) but that this relaxivity increase (of 300%) is limited by a slow water exchange (660 ns). To overcome this limitation, a second ligand called MTS-CyDOTA has been synthesized. This ligand is a DOTA ligand grafted with a cyclohexyl ring featuring a MTS function. The synthesis is more demanding but faster water exchange times are expected because of a more sterically crowded coordination sphere. Moreover, this second ligand has a more rigid structure that could limit the independent rotation of the chelate from the macromolecule. As expected, the water exchange time of the Gd(III) chelate of this ligand (120 ns) is clearly lower than the one determined for Gd MTS-ADO3A. After binding to albumin or to silica nanoparticles a notable relaxivity increase was expected. Unfortunately, if the obtained relaxivity is higher (30 mM-1s 1, 20 MHz, 25°C), its not as high as it could have been expected in view of the size of the conjugate and of the water exchange time of the free chelate. Results obtained in this work suggest that fixation on silica nanoparticles or on albumin drastically decreases the water exchange rate which remains the limiting parameter. This effect has already been reported for Gd(III) chelates linked to albumin by non-covalent bonds and has been assigned to stable layers of water molecules on the macromolecule surface. Thanks to the high loading of the silica nanoparticles (10000 Gd(III) per particle), we have reached very high molecular relaxivities (>200000 mM-1s-1). Stability tests carried out on the disulfide links formed suggest that the small amount of free thiols in the circulation is not sufficient to cause a significant degradation of the disulfide bond in the conjugate within a reasonable length of time. An injection of glutathione would be necessary to achieve a complete degradation. To avoid the problem of water exchange lenghtening, we propose to increase the distance between Gd(III) chelates and macromolecules without loss of rigidity by developing double anchor chelates with substituents grafted on the side of the ring. Considerable synthetic efforts have devoted to the synthesis of such a system and are discussed in chapter VI. At present, this work is still in progress in the laboratory and recent results suggest that it should be possible to evaluate this double arms system in a near future. On the fringe of this synthesis, we present a relaxometric study on the interaction between HSA and a hydrophobic Gd(III) chelate obtained during the preparation of our double anchor chelate. Finally, a chapter of this work is devoted to the study of two compounds, phenEDTA and phenDTPA, which are ditopic chelates featuring a dihydro-1,10-phenanthroline unit that spontaneously self-assemble in the presence of a transition metal ion. The tris-complex generated by this process rotates more slowly in solution and thus presents an increased relaxivity (+130%). As part of this work, we have determined by potentiometric titration the acidity constants of phenEDTA and its stability constant with Gd(III). Moreover, the protonation scheme of this ligand has been studied by NMR titration. The particular behavior of Gd phenDTPA and Fe(Gd phenDTPA)3 in the presence of Zn(II) has also been studied by relaxometry, luminescence and EXAFS.

In the media today, remuneration programs to CEO’s are frequently discussed. Media are usually focusing on the large amounts paid out rather than why the companies use the programs. The purpose of this thesis is to examine whether the conflict of interest presented by the Principal Agent Theory is affected by a CEO remuneration program. To reach the purpose, an inductive method has been used. Questionnaires have been send out by e-mail and phone interviews have been carried out with two sample groups, one with remuneration programs, and one that do not use remuneration programs. The main theoretical framework used is Principal Agent Theory. With the help of other supporting and complementing theories the authors have been able to analyze the empirical findings gathered, and come to a conclusion. The authors were able to come to the conclusion that an effective remuneration program can to some extent steer a CEO’s behavior in the short term, and thereby affect the conflict of interest going on between principals and agents according to Principal Agent Theory. At the same time the authors have come to the conclusion that it is more difficult to make any clear connections between remuneration programs and being able to steer CEO’s behavior in the long run. However the long run reason for a remuneration program is to create a loyalty between the owners and managers. It has also been seen that companies without a remuneration plan tend to apply a Stewardship relationship rather than a principal agent relationship, and are thereby managing to decrease the conflict of interest between the two parties. / Bonusprogram är ofta diskuterade i media idag. Fokus ligger oftare på storleken på beloppen som betalas ut snarare än varför företagen väljer att använda sig av programmen. Syftet med den här uppsatsen är att undersöka huruvida intressekonflikten presenterad i Principal Agent Teori påverkas av ett bonusprogram till VD. För att uppnå syftet har en induktiv metod används. Frågeformulär har skickats ut via e-post och telefonintervjuer har genomförts med två olika urvalsgrupper, en där företagen använder sig av bonusprogram till sin VD och en där företagen inte använder sig av bonusprogram till sin VD. Den huvudsakliga teorin som använts är Principal Agent Teori. Med hjälp av andra stödjande samt kompletterande teorier har författarna kunnat analysera det empiriska materialet som samlats in och på så sätt lyckats komma fram till en slutsats. Författarna kom fram till slutsatsen att ett effektivt bonusprogram kan till viss del styra en VD:s beteende på kortsikt, och på så sätt påverka den intressekonflikt som pågår mellan principal och agent enligt Principal Agent Teorin. Samtidigt har författarna kommit fram till slutsatsen att det är svårare att se något klart samband mellan bonusprogram och möjligheten att styra en VD:s beteende på långsikt. En annan anledning för att använda ett bonusprogram är att skapa en lojalitet mellan ägare och chefer på långsikt. Det har även framkommit att företag som inte använder sig av ett bonussystem tenderar att ha en Stewardship relation snarare än en principal agent relation mellan ägaren och VD. På så sätt lyckas dessa företag minska intressekonflikten mellan de två parterna.

This dissertation investigates selected empirical and theoretical aspects of land-use and land-cover change (LUCC) in exurban areas. Two challenges – observation and monitoring of LUCC, and spatially explicit modeling, are addressed using three main approaches – measuring, reviewing and agent-based modeling (ABM). All of these approaches focus on LUCC at the individual household level, investigating how micro-scale elements interact to influence macro-scale functional patterns—bottom-up analysis. First, the temporal change of the quantity and pattern of land-cover types within exurban residential parcels in three townships in the southeastern Michigan is examined using landscape metrics and local indicators of spatial association at the parcel and parcel-neighborhood level respectively. The results demonstrate that the number and area of exurban residential parcels increased steadily from 1960 to 2000, and different land-cover types have distinctive temporal changes over time. The results also indicate that there is a convergence process at the neighborhood level through which the quantity and pattern of land cover in parcels conform with the neighborhood appearance. Second, 51 urban residential choice models based on ABM are reviewed. The results divide these models into three categories (i.e. models based on classical theories, models focusing on different stages of urbanization process; and integrated ABM and microsimulation models). This review also compares the differences among these models in their representations of three essential features brought by the technique of ABM: agent heterogeneity, the land market and output measurement. Challenges in incorporating these features, such as the trade-off between the simplicity and abstraction of model and the complexity of urban residential system, interactions of multiple features and demands for data at individual level, are also discussed. Third, the effects of agent heterogeneity on spatial and socioeconomic outcomes under different levels of land-market representations are explored through three experiments using a stylized agent-based land-market model. The results reveal that budget heterogeneity has prominent effects on socioeconomic outcomes, while preference heterogeneity is highly pertinent to spatial outcomes. The relationship between agent heterogeneity and macro-measures becomes more complex as more land-market mechanisms are represented. The results also imply that land-market representation (e.g., competitive bidding) is indispensable to reproduce the results of classical urban land market models (e.g., monocentric city model) in a spatial ABM when agents are heterogeneous.

Controlling systems with multiple robots is quickly becoming the next large hurdle that must be overcome for groups of robots to successfully function as a team. An agent oriented approach for this problem is presented in this thesis. By using an agent oriented method, the robots can act independently yet still work together. To be able to establish communities of robots, a basic agent oriented control system for each robot must first be implemented. This thesis introduces a novel method to create Physical Robot Agents, promoting a separation of cognitive and reactive behaviours into a two layer system. These layers are further abstracted into key subsections that are required for the Physical Robot Agents to function. To test this architecture, experiments are performed with physical robots to determine the feasibility of this approach. <br /><br /> A real-time implementation of a Physical Robot Agent would greatly expand its field of use. The speed of internal communication is analyzed to validate the application of this architecture to real-time tasks. <br /><br /> It is concluded that the Physical Robot Agents are well suited for multiple robot systems and that real-time applications are feasible.