Cette thèse porte sur des stratégies distribuées pour systèmes multi-robot. Tout d'abord, nous nous focalisons sur des algorithmes de consensus pour des systèmes hétérogènes qui représente, par exemple, différents modèles ou générations de robots. Dans la suite, nous proposons deux solutions pour améliorer les propriétés de connectivité du système. Tout d'abord, nous montrons comment améliorer la vitesse de convergence des algorithmes de consensus en modifiant les protocoles classiques. Plus précisément, nous appliquons le principe de retard stabilisant et nous montrons comment de l'information échantillonné convenablement peut être utilisée dans la design du contrôleur. Enfin, nous concevons et analysons un algorithme pour le déploiement d'agents compact. Dans cette approche, qui augmente le nombre de connexions du graphe, la configuration souhaitée de l'ensemble des robots est entièrement spécifiée par les angles inter-agents. La stratégie proposée est un algorithme complètement distribué, uniquement basée sur l'information locale qui permet l'auto-organisation du système. / This dissertation focuses on distributed agreement strategies for multi-robot systems. First of all, we deal with consensus algorithms for heterogeneous systems, representing, for example, different models or generations of robots. In the sequel, we propose two solutions to improve the connectivity properties of the system. Firstly, we show how to improve the consensus algorithm's convergence rate by modifying the classical control algorithms. More precisely, we apply the stabilizing delay principle and we show how appropriately sampled information can be used in the controller's design. Finally, we design and analyse an algorithm for the compact deployment of agents. In this approach, that increases the number of connections of the graph, the desired configuration of the swarm is entirely specified by the inter-agent angles. The proposed strategy is a completely distributed algorithm, only based on local information that allows swarm's self-organization.

Nous construisons un simulateur de marche financier multi-agent. Dans cette marche l'échange des actions n'est pas fait en continu. Le prix de marché est formé à l'aide d'un carnet d'ordres. Les investisseurs que l'on modélise reçoivent de l'information biaisée et ils essayent de maximiser leur richesse. Les différents types d'investisseurs, comme les bruiteurs, chartistes ou informées, coexistent dans notre marche. On montre comment les faites stylises peuvent être causée par la présence des investisseurs chartistes ou par des simple délais dans l'information. Nous montrons comment les bulles de prix sont possibles dans un marché avec des investisseurs bien informés. On découvre que c'est profitable, pour un investisseur informé, d'adopter dans certaines moments des stratégies techniques. A partir de nos résultats nous proposons une nouvelle théorie sur la dynamique des marchés financiers, appelé « marches parfois efficientes ». / We construct an agent-based computer simulated financial market. Trading in this market is not continuous. The market price is formed using a limit-order book. The modelled investors receive biased information and they attempt to maximize their wealth. Different traders, from noise to chartist and informed, coexist in the same market. We show how stylized facts can be formed by the presence of chartists or a simple lag in investor information. Price bubbles can arise when market prices are dominated by technical traders. Interestingly we show that well informed investors can earn more if the adopt, in special situations, a technical strategy. Using our results we propose a new theorem for market dynamics called “sometimes efficient markets”.

O problema do Desaparecimento do Agente é uma objeção que tem assolado a Teoria Causal da Ação ao longo da maior parte da sua história contemporânea, mesmo tendo essa teoria se tornado a ortodoxia da explicação de ações. A objeção questiona qual seria o papel do agente, se é que ele teria algum, se apenas seus estados mentais parecem ter um papel causal relevante na produção de ações, como afirma a Teoria Causal da Ação. Essa questão permanece sem resposta satisfatória e recentemente tem originado até mesmo versões recentes do problema do Desaparecimento do Agente que levam o Livre Arbítrio e a consciência em consideração como sendo centrais para o debate. Assim, aceitar a Teoria Causal da Ação requer lidar com o problema em questão. Esse debate se beneficiará do diálogo com a psicologia e a neurociência e, com base nessa troca, eu argumentarei que o problema do Desaparecimento do Agente surge de uma concepção equivocada do que seria um agente humano e qual seria o seu papel na produção de suas ações. Isso se torna claro quando percebemos que essa concepção não corresponde ao nosso conhecimento científico atual a respeito da produção das ações humanas. Aceito isso, eu proponho então uma concepção diferente de agentes que não permite o surgimento do problema do Desaparecimento do Agente. / The problem of the Disappearing Agent is an objection that has haunted the Causal Theory of Action for most of its contemporary history, even if this theory has become the orthodoxy of action explanation. The objection questions what role, if any, is reserved for the agent, if only her mental states seem to have a relevant causal role in the production of action, as the Causal Theory of Action would have it. This question remains unsatisfactorily answered, and has even originated recent versions of the Disappearing Agent issue, which take Free Will and consciousness as being at the center of the debate. Therefore, acceptance of the Causal Theory of Action requires dealing with such problem. This debate will benefit from a dialog with psychology and neuroscience, and based on this exchange I will argue that the issue of the Disappearing Agent springs from a misguided conception of what is a human agent and what is the agents role in the production of her action. This becomes clear when we realize that this conception does not correspond to our current scientific knowledge about the production of human action. Accepting this, I then propose a different conception of agents that does not allow for the Disappearing Agent problem to rise.

This work presents the concept of code and data propagation in a multi-agent system. First, the concepts of agent and multi-agent system are defined and examples are presented. Also arguments for using agent approach are given and potential benefits are listed. Afterwards the idea of code and data propagation is defined and explained. Then some examples of real solutions are given along with propagation algorithms, which depict the way of introducing the concept into real system solutions. Afterwards the code and data propagation in a multi-agent system is described, which is in many cases based on the object migration. Discussion about this concept ends with describing the types of agent migration and giving some examples of systems with agent migration. Then three multi-agent environments are described and one is chosen to be the basis of the implemented application. Second part of work starts with description of systems principal objective, which is the distributed calculating of prime numbers. At the beginning, agents of the system are presented, and then the main system processes are depicted in detail. All algorithms are shown in sequence diagrams, which point all asynchronisms in the system. Afterwards migration phase is described with all migration types and algorithms. The experiments are conducted in two environments: home and university. The main aim is to find optimal configurations for both environments. The conclusion from this work is that introducing code and data propagation to a multiagent system in a form of agent migration in a heterogeneous network could considerably decrease the execution time. Moreover based on the efficiency vector of computers participating in the experiment there is a possibility to set a task distribution, which is close to optimal, without searching for optimal configuration every time when running the experiment.

There are many games that have been a challenge to Research in Artificial Intelligence. One such game is Settlers of Catan (SoC). The purpose of this thesis is to develop a Multi-agent player for SoC. Although it is difficult to focus on all the dimensions of the game during implementation, therefore a good enough solution is proposed. An emphasis is placed on building a good trader for the player. Once a working solution had been built, the player was tested against other players which included human players as well as bots.

Abstract The use of agent systems has increased enormously, especially in the field of mobile services. Intelligent services have also increased rapidly in the web. In this thesis, the utilization of software agent technology in mobile services and decentralized intelligent services in the multimedia business is introduced and described. Both Genie Agent Architecture (GAA) and Decentralized International and Intelligent Software Architecture (DIISA) are described. The common problems in decentralized software systems are lack of intelligence, communication of software modules and system learning. Another problem is the personalization of users and services. A third problem is the matching of users and service characteristics in web application level in a non-linear way. In this case it means that web services follow human steps and are capable of learning from human inputs and their characteristics in an intelligent way. This third problem is addressed in this thesis and solutions are presented with two intelligent software architectures and services. The solutions of the thesis are based on a combination of neural network and agent technology. To be more specific, solutions are based on an intelligent agent which uses certain black box information like Self-Organized Map (SOM). This process is as follows; information agents collect information from different sources like the web, databases, users, other software agents and the environment. Information is filtered and adapted for input vectors. Maps are created from a data entry of an SOM. Using maps is very simple, input forms are completed by users (automatically or manually) or user agents. Input vectors are formed again and sent to a certain map. The map gives several outputs which are passed through specific algorithms. This information is passed to an intelligent agent. The needs for web intelligence and knowledge representation serving users is a current issue in many business solutions. The main goal is to enable this by means of autonomous agents which communicate with each other using an agent communication language and with users using their native languages via several communication channels.

Les travaux de cette thèse s’inscrivent dans le domaine des systèmes complexes et s’intéressent plus particulièrement à l’exécution efficace et reproductible de simulations multi-agents de grande taille dans un contexte parallèle et distribué de haute performance de type cluster (HPC). Dans ce contexte, nous nous intéressons plus particulièrement à la conception des modèles pour faciliter leur distribution, à la synchronisation des composants distribués et à la communication entre agents. La première contribution de cette thèse est la comparaison qualitative et quantitative des principales plateformes multi-agents parallèles et distribués qui ciblent les simulations à large échelle dans un environnement haute performance.Ce travail a permis d’identifier les limites ou manques des plateformes existantes, majoritairement la communication entre les agents, la synchronisation ainsi que la distribution de la charge peu flexible. Pour offrir plus de flexibilité à la distribution des simulations, nous proposons un formalisme de modélisation à base de graphes imbriqués qui nous permet de tirer parti de librairies performantes pour décomposer et distribuer les simulations. Nous avons ensuite effectué une étude sur l’impact de la synchronisation dans les PDMAS, en proposant trois politiques de synchronisation différentes afin de fournir aux modélisateurs un niveau de résolution adapté aux différents problèmes de synchronisation. Pour finir, nous définissons un schéma de communication entre toutes les entités qui composent une simulation indépendamment du processus sur lequel les entités s’exécutent. Ces propositions sont réunies au sein d’une plateforme multi-agents parallèle appelée FractalPMAS. Cette plateforme est une preuve de concept qui nous a permis de mettre en œuvre nos différentes contributions afin d’observer et de comparer les comportements de nos algorithmes. Pour valider ce travail trois modèles agents reconnus, le modèle proie-prédateur, le modèle Flocking et un modèle de contamination, ont été utilisés. Nous avons réalisé des simulations utilisant jusqu’à 512 cœurs et les résultats obtenus, en termes de performances et d’extensibilité, s’avèrent prometteurs. / Contributions of this PHD take place on computer science research on complex systems, specifically in efficient andreproducible execution of large multi-agent simulations in a parallel and distributed high performance cluster type of context(HPC) systems. We are particularly interested in the design of models to facilitate their distribution, synchronization ofdistributed components and communication between agents. In this context, we are particularly interested in the designof models to facilitate their distribution, synchronization of distributed components and communication between agents.The first contribution of this thesis is the qualitative and quantitative comparison of the main parallel and distributedmulti-agent platforms targeting large scale simulations in a high performance environment. This work identified limitationsof existing platforms, mainly communication between agents, synchronization and the distribution of the load which isinflexible. To offer more flexibility in the distribution of simulations, we propose a modeling formalism based nested graphsallowing us to decompose and distributed simulations using powerful libraries. We then conducted a study on the impactof synchronization in PDMAS, proposing three different synchronization policies to provide modelers a level of resolutionadapted to the various synchronization problems. Finally, we define a communication schema between all entities thatmake up a simulation regardless of the process on which entities are running.These contributions are combined in a parallel multi-agent platform called FractalPMAS. This platform is a proof of conceptand allowed us to implement our different contributions to observe and compare the behavior of our algorithms. To validatethis work three recognized agents model, the predator-prey model, the Flocking model and contamination model wereused. We performed simulations using up to 512 cores and the results obtained, in terms of performance and scalabilityare promising.

Dans un contexte de croissance des diagnostics préventifs, la demande en produits de contraste augmente, tandis que leur prix de revient industriel doit être revu à la baisse pour des raisons de compétitivité. La voie de synthèse d’un produit de contraste à rayons X, molécule iodée aux branchements hydrophiles, comporte plusieurs réactions : certaines sont limitées par le transfert de matière (milieu réactionnel polyphasique) ou par le transfert de chaleur (réaction exothermique) tandis que d’autres sont limitées cinétiquement. Les performances des équipements continus intensifiés permettent de favoriser les phénomènes de transfert de matière et de chaleur, tout en garantissant une bonne sélectivité et reproductibilité. La chaine de synthèse globale est repensée en vue d’un passage en mode continu intensifié et les réactions à étudier en intensification locale sont classées par ordre de priorité selon leur potentiel d’intensification. A partir d’une approche combinée alliant résultats expérimentaux et simulation, des modèles réactionnels peuvent être construits pour orienter les essais, afin de converger rapidement vers des conditions opératoires menant aux performances souhaitées. La nouvelle voie de synthèse proposée mettra ainsi en jeu une alternance entre étapes continues et discontinues, ce qui induit des difficultés en termes de gestion de procédé. Une voie de synthèse entièrement soluble permettrait de contourner les limitations d’intensification dues à la présence de solides et d’envisager la chaine de synthèse globale en continu / Preventing diagnostics are increasing and so is the demand for contrast media while its industrial cost needs to be decreased for competitiveness reasons. The synthesis route for a contrast media used in X-ray medical imaging, an iodinated molecule with hydrophilic functional groups, is made of several reactions: some of them are limited by heat transfer (exothermic reactions) or/and mass transfer (multiple-phase media) while others are kinetically limited. The use of continuous intensified equipment leads to enhanced heat and mass transfer performances while keeping good selectivity and reproducibility. The synthesis route is globally modified in the first place in order to shift from batch to continuous intensified and the reactions are classified for local intensification studies. A combined approach based on experimental measurements and simulation enables the building of reaction models which can be used as a guideline for the experiments towards finding the operating conditions that lead to the desired performances at laboratory scale. The new synthesis route production is based on an alternation between continuous and discontinuous steps, which leads to difficult production management. New prospects are created with a new hydrophilic synthesis route, where the limitations for shifting from batch to continuous due to the presence of solids are solved and the whole synthesis route can be transferred from batch to continuous mode

This diploma thesis deals with the usage of agents in business process modelling. The aim is to identify possible uses in the problem area and to evaluate their potential. Intended usage is analysed on the basis of the objectives of process modelling. Described in detail, it focuses on potential application of agents in a process modelling itself, in deploying executable and flexible processes, process improvements and finally in dynamic planning. A further objective is to provide an overview of current research and literature in problem area. To fulfil the goal available literature is analysed and basis approaches are demonstrated in case study. Paper does not address the implementation of multi-agent systems (MAS). Following introduction reader is guided though basic elements of the processes and their modelling, concept of agents and modelling of MAS. As a process modelling notation BPMN in planned 2.0 release was selected. Next section is devoted to the usage of agents. The last part of the work is a case study discussing the possibilities of agents application in company operating public car auctions. In addition the process model (BPMN) transformation to agent model is presented and further developed as a interconnection between process modelling and agent-based systems. Combination of agent approach with business rules and hybrid simulation are proposed as the most promising usages.

Les opérations chirurgicales pour le traitement des défauts de soutènement d'organes dans les pays industrialisés sont des actes de plus en plus fréquents, et requièrent l'implantation de plus d'un million de prothèses par an. Même si l'usage des prothèses de soutènement a permis de diminuer les complications postopératoires, les taux de réinterventions restent très élevés. Ces travaux présentent différentes stratégies permettant d'apporter de nouvelles propriétés à des treillis en polypropylène, afin d'améliorer leur résistance à l'infection et de permettre leur suivi postopératoire en IRM. Des treillis anti-infectieux sont développés en enrobant les filaments de treillis d'un réservoir de polymère dégradable et biocompatible contenant des agents anti-infectieux, par une technique de pulvérisation à l'aide d'un aérographe. L'association ofloxacine – rifampicine incorporée présente une excellente activité antibactérienne in vitro, et la cinétique de libération prolongée des agents actifs permet d'inhiber la contamination des treillis pendant au moins 72 heures. Les techniques de stérilisation par rayonnement Gamma n'impactent ni la stabilité des agents actifs, ni l'efficacité antibactérienne des treillis anti-infectieux.Afin de permettre une visualisation en IRM des treillis implantés, des polymères ont été synthétisés par greffage d'agent de contraste (DTPA-Gd) sur de la poly(ε-caprolactone) (dégradable) et du poly(acrylate de méthyle) (biostable). Après enrobage des prothèses par ces polymères, le rehaussement du signal induit par la présence du gadolinium permet de visualiser les prothèses à la fois in vitro et in vivo sur différents types d'appareils d'IRM. La stabilité de l'agent de contraste est suffisante pour pouvoir visualiser les treillis pendant plusieurs mois, quelle que soit la technique de stérilisation utilisée. / Soft tissue reinforcement surgical operations in industrial countries are common and require annually at least one million of prostheses for treating this problem. Even if meshes used for organ prolapse surgical procedures allow decreasing postoperatory complications, reinterventions ratio is still relevant. This work present several strategies to bring new properties to polypropylene meshes in order to improve their resistance to infection and enable their postoperative MRI follow-up. Anti-infective meshes are developed by coating the filaments of the meshes with an antibiotics drug reservoir based on degradable and biocompatible polymers, using an airbrush system. Dual ofloxacin-rifampicin antibiotics incorporation on these coated meshes shows an excellent antibacterial activity in vitro and sustained release of the drugs can inhibit meshes contamination for at least 72 hours. Sterilization procedures using Gamma-ray irradiation impact neither the drugs stability nor the anti-infective meshes activity. In order to visualize by Magnetic Resonance Imaging (MRI) meshes after implantation, a contrast agent (DTPA-Gd) is covalently grafted onto the polymeric backbone of poly(ε-caprolactone) (degradable) or poly(methyl acrylate) (biostable). Meshes were coated with these new polymers and MR signal enhancement induced by the presence of gadolinium allows the visualization of the meshes in vitro and in vivo with several MR equipments. Coated meshes are visible during several months, whatever the sterilization procedures, showing the stability of the contrast agent.