The aim of this work is design, implementation and experimental evaluation of distributed algorithms for planning actions of a team of cooperative autonomous agents. Particular algorithms require different amount of communication. In the work, the related research on Monte-Carlo tree search algorithm, its parallelization and distributability and algorithms for distributed coordination of autonomous agents. Designed algorithms are tested in the environment of the game of Ms Pac-Man. Quality of the algorithms is tested in dependence on computational time, the amount of communication and the robustness against communication failures. Particular algorithms are compared according to these characteristics. Powered by TCPDF (www.tcpdf.org)

The thesis deals with the study of the computer worm meeting several criteria (it should be fully distributed, decentralized and stealthy). These conditions lead to anonymity, longevity and better security of our worm. After presenting the recently used architectures and new technologies we analyse the known implementations. We propose the solutions with the new design together with the possible ways of improvements. In the next chapter we study biological concepts suitable for the new replication mode, where we implement the key concepts of functionality in a higher programming language. At design we have considered as important to be platform independent, so it is possible for the worm to spread in almost every computer environment, in dependence of implementation of the required modules. Powered by TCPDF (www.tcpdf.org)

Approved for public release, distribution is unlimited / problem, with engine thrust as the only possible perturbation. The optimal control problems are solved using the general purpose dynamic optimization software, DIDO. The dynamical model together with the fuel optimal control problem is validated by simulating several well known orbit transfers. By replicating the single satellite model, this thesis shows that a multi-satellite model which optimizes all vehicles concurrently can be easily built. The specific scenario under study involves the injection of multiple satellites from a common launch vehicle; however, the methods and model are applicable to spacecraft formation problems as well. / Major, United States Air Force

Dans la zone nord des bassins versants de la Thaïlande, l'augmentation de la dégradation des ressources du bassin hydrographique résultant de la combinaison de l’augmentation de la population et de la croissance économique ont conduit à la création de contrôles divers par différents agents. Le gouvernement thaïlandais a fait des efforts considérables pour responsabiliser et impliquer les populations locales dans la gouvernance des ressources, pour éradiquer le problème et atténuer les conflits d'intérêts. Toutefois, la participation de la population ne progresse pas au-delà des niveaux d'information et de consultation. Afin de promouvoir la bonne gouvernance des ressources, la question de recherche proposée ici est de savoir comment utiliser la modélisation d'accompagnement (ComMod) qui est un processus de médiation outillé pour promouvoir la compréhension mutuelle et l'apprentissage adaptatif chez les intervenants afin d’améliorer la gestion collective des bassins versants. Les principales méthodes de recherche mises en œuvre dans cette étude sont le jeu de rôle (RPG), l'observation participante et la modélisation multi-agents. L'analyse préliminaire du cas du bassin versant Maehae a révélé un risque de conflit entre les agriculteurs et les forestiers. Deux sessions de jeu de rôle (RPG) ont été menées afin de mieux comprendre comment ces acteurs utilisent et gèrent des terres et des forêts malgré des conflits d'intérêts. […]En résumé, le réseau villageois, comme le réseau local, crée des liens divers entre deux ethnies et communautés. Il lie des individus, des groupes et des réseaux plus politiques et se pose en tant qu'intermédiaire informel politique pour co-gérer les ressources du bassin hydrographique et atténuer les tensions éventuelles entre les parties prenantes. La fonction du réseau villageois représente un processus d'évolution culturelle par le biais de l'apprentissage social et permet d’accroitre les préoccupations environnementales, et par conséquent, accroît la capacité d'adaptation la résilience. Cette étude […] souligne l'importance de la participation des principales parties prenantes, la confiance entre le chercheur et les acteurs, la position neutre du chercheur. La prochaine étape dans la modélisation d'accompagnement serait nécessaire, pour partager le plan de gestion collective locale avec les réseaux politiques plus interconnectés, grâce à la simulation du modèle, et passer à d'autres co-planifications et co-décisions en matière de gouvernance durable des ressources des bassins versants. / In the northern watershed area of Thailand, the increase in watershed resources degradation due to the combination of population and economic growths led to diverse controls and responsible agents. Thai government has put substantial effort to empower and involve local people in resource governance, to eradicate the problem and mitigate the conflict of interest. However, the people participation does not progress beyond informative and consultative levels. The Maehae is one of the complex watershed management cases where intensive vegetable cultivated lands located in restricted watershed area, multi-level stakeholders involved in watershed resources management existed. To promote good resource governance, the research questions proposed here is how to employ companion modeling (ComMod) process and mediating tools to promote mutual and adaptive learning among stakeholders to enhance collective watershed management. The main field research methods implemented in this study are roleplaying game (RPG), stakeholders observation and multi-agent based model (MABM). Preliminary system analysis of the Maehae revealed a potential conflict among the farmers and the forester. Two land-forest role-playing game (RPG) sessions were conducted in order to gain a better understanding on how these stakeholders use and manage land and forest under conflict of interests. […]This scenarios exploration showed that the San was only determinant factor in the “business as usual” scenarios. The San […] could reduce forest disturbance and promoted total farm productivity. […] In summary, The Maehae village network, as the local network, bridges diverse ties both ethnicities and communities. It links individual, groups and higher policy network; performs as intermediary informal political network to co-manage the watershed resources and mitigate possible tensions among stakeholders. The village network function represents a cultural evolution process through social learning and gaining of environmental concerns, therefore, enhances adaptive capacity and increase resilience. This study […] recommends the important of key stakeholders’ involvement, the trust between researcher and the stakeholders, the neutral position of the researcher. Further stage of companion modelling would be required, to share collective local management plan with larger interconnected policy networks, through the model simulation, and move to further co-planning and codecision making for sustainable watershed resource governance.

Autonomic Computing (AC) aims at solving the problem of managing the rapidly-growing complexity of Information Technology systems, by creating self-managing systems. In this thesis, we have surveyed the progress of the AC field, and studied the requirements, models and architectures of AC. The commonly recognized AC requirements are four properties - self-configuring, self-healing, self-optimizing, and self-protecting. The recommended software architecture is the MAPE-K model containing four modules, namely - monitor, analyze, plan and execute, as well as the knowledge repository. In the modern software marketplace, Java Management Extensions (JMX) has facilitated one function of the AC requirements - monitoring. Using JMX, we implemented a package that attempts to assist programming for AC features including socket management, logging, and recovery of distributed computation. In the experiments, we have not only realized the powerful Java capabilities that are unknown to many educators, we also illustrated the feasibility of learning AC in senior computer science courses.

This report describes a distributed approach to social filtering based on the agent metaphor. Firstly, previous approaches are described, such as cognitive filtering and social filtering. Then a couple of previously implemented systems are presented and then a new system design is proposed. The main goal is to give the requirements and design of an agent-based system that recommends web-documents. The presented approach combines cognitive and social filtering to get the advantages from both techniques. Finally, a prototype implementation called WebCondor is described and results of testing the system are reported and discussed.

Double (or multiple) marginalization is often identified as the main source of a decentralized supply chain's (SC's) inefficiency. In its core lies the fact that if the agents constituting the SC choose their output prices according to the golden rule of profit maximization (that normally applies to a single firm that produces independently and sells directly to the end consumer), the prices in the SC tend to spiral up to an inefficient (equilibrium) level where both the consumer surplus and the SC's total profit are diminished. The aim of this paper is to analyze and quantify the impact of multiple marginalization on the behaviour of SC's that vary with respect to their structure (i.e. the number of agents and the links between them) and the shape of their cost and demand functions. The main gauge of this impact is the efficiency of a SC, defined as the ratio of the profit of a SC whose agents behave according to the model of multiple marginalization, and the potential profit of the SC (i.e. the maximum profit attainable under the conditions of complete coordination of prices within the chain). Besides efficiency, some other properties of a SC are studied, e.g. the distribution of the SC's profit among the individual agents or cost externalities within the SC. Three different models of multiple marginalization are studied in the paper. The first one is a linear model of multiple marginalization (i.e. a model with linear demand and cost functions); in this simplified setting we derived explicit formulae for values of the studied indicators. The second model is analogous to the first one only that it allows for non-linear demand and cost functions; in this case, the analysis is carried out using computer experiments with numeric algorithms. The last one is a dynamic model of multiple marginalization which studies the abovementioned price spiral through multi-agent simulation.

[pt] Sistemas multi-agentes são sociedades com agentes autônomos e heterogêneos que podem trabalhar em conjunto para alcançar objetivos similares ou totalmente diferentes. Quando falhas acontecem enquanto algum agente de software tenta alcançar seus objetivos, torna-se importante entender porque tais falhas acontecem e o que pode ser feito para remediar tais problemas. Considerando o ambiente distribuído, dinâmico e a natureza dos sistemas multi-agentes, é importante definir os requisitos necessários para realizar diagnósticos das falhas e recomendações de planos alternativos para agentes que desejam alcançar seus objetivos. Assim, esta dissertação propõe soluções para os principais desafios de criar um sistema que realize diagnósticos e proveja recomendações sobre execuções de agentes. Além disso, o trabalho propõe um framework híbrido de diagnóstico e recomendação que provê suporte para tais desafios. A partir do framework, instâncias de diferentes domínios podem ser criadas, como, por exemplo, aplicações baseadas em computação ubíqua e diferentes diagnósticos e recomendações podem ser providas. / [en] Multi-agent systems are societies with autonomous and heterogeneous agents that can work together to achieve similar or different goals. Agents executing in such systems may not be able to achieve their goals due to failures during system execution. When an agent tries to achieve its desired goals, but faces failures during execution, it becomes important to understand why such failures occurred and what can be done to remedy the problem. The distributed, dynamic and nature of multi-agent systems calls for a new form of failure handling approach to address its unique requirements, which involves both diagnosing specific failures and recommending alternative plans for successful agent execution and goal attainment. We discuss solutions to the main challenges of creating a system that can perform diagnoses and provide recommendations about agent executions to support goal attainment, and propose a hybrid diagnostic-recommendation framework that provides support for methods to address such challenges. From the framework, instances of different domains can be created, such as, applications based on ubiquitous computing and different diagnoses and recommendations can be provided.

Disasters especially from natural phenomena are inevitable. The affected areas recover from the aftermath of a natural disaster with the support from various agents participating in humanitarian operations. There are several domains of the operation, and distributing relief aids is one. For distribution, satisfying the demand for relief aid is important since the condition of the environment is unfavorable to affected people and resources needed for the victim’s life are scarce. However, it becomes problematic when the logistic agents believed to be work properly fail to deliver the emergency goods because of the capacity loss induced from the environment after disasters. This study was proposed to address the problem of logistic agents’ unexpected incapacity which hinders scheduled distribution. The decrease in a logistic agent’s supply capability delays<br>achieving the goal of supplying required relief goods to the affected people which further endangers them. Regarding the stated problem, this study explored the importance of<br>setting the profile of logistic agents that can survive for certain duration of times. Therefore, this research defines the “survivability” and the profile of logistic agents for surviving the last mile distribution through agent based modeling and simulation. Through simulations, this study uncovered that the logistic exercise could gain survivability with the certain number and organization of logistic agents. Proper formation of organization establish the logistics’ survivability, but excessive size can threaten the survivability.

Depuis plusieurs décennies, la congestion urbaine est de plus en plus répandue et dégrade la qualité de vie des habitants des villes. Plusieurs méthodes sont utilisées pour diminuer la congestion urbaine, notamment la régulation du trafic et la valorisation des transports en commun. Depuis les années 1990 l'utilisation d‘outils issus de l'intelligence artificielle, et en particulier des méthodes distribuées et les systèmes multi-agents, a permis de concevoir de nouvelles méthodes de régulation du trafic. Parallèlement, l'amélioration des capacités de communication des véhicules et des conducteurs et l'arrivée de voitures autonomes permettent d'envisager de nouvelles approches en matière de régulation. Le travail de recherche proposé dans le cadre de cette thèse est structuré en deux volets. Nous proposons d'abord une méthode de régulation du trafic à une intersection s'appuyant sur la négociation automatique. Notre méthode se fonde sur un système d'argumentation décrivant l'état du trafic et les préférences de chacun, appuyé par des méthodes de raisonnement pour les véhicules et les infrastructures. Dans le deuxième volet de cette thèse, nous proposons une méthode de coordination des bus avec le reste du trafic. Celle-ci permet à un bus de se coordonner de manière anticipative avec les prochaines intersections qu'il prévoit de traverser, afin de mettre en place une politique commune de régulation qui permet au bus d'atteindre son prochain arrêt en subissant le minimum de congestions potentielles / Since several decades, urban congestion is more and more widespread and deteriorate the quality of life of citizens who live in cities. Several methods are used to reduce urban congestion, notably traffic regulation and promotion of public transportation. Since the 1990's, the usage of tools from artificial intelligence, particularly distributed systems and multi-agent systems, allowed to design new methods for traffic regulation. Indeed, these methods ease to take into account the complexity of traffic-related problems with distribution. Moreover, the improvement of the communication abilities of the vehicles and the coming of autonomous vehicles allow to consider new approaches for regulation.The research work presented in this work is twofold. First we propose a method for traffic regulation at an intersection based on automatic negotiation. Our method is based on an argumentation system describing the state of the traffic and the preferences of each vehicle, relying on reasonning methods for vehicles and infrastructures. In the second part of this thesis, we propose a coordination method for buses for the rest of the traffic. This method allows a bus to coordinate in an anticipatory way with the next intersections on its trajectory, in order to define a common regulation policy allowing the bus to reach its next stop without suffering from potential congestions