Dissertations / Theses: 'Autonomous agents and multiagent systems'

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Hurt, David. "An Empirical Evaluation of Communication and Coordination Effectiveness in Autonomous Reactive Multiagent Systems." Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4770/.

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This thesis describes experiments designed to measure the effect of collaborative communication on task performance of a multiagent system. A discrete event simulation was developed to model a multi-agent system completing a task to find and collect food resources, with the ability to substitute various communication and coordination methods. Experiments were conducted to find the effects of the various communication methods on completion of the task to find and harvest the food resources. Results show that communication decreases the time required to complete the task. However, all communication methods do not fare equally well. In particular, results indicate that the communication model of the bee is a particularly effective method of agent communication and collaboration. Furthermore, results indicate that direct communication with additional information content provides better completion results. Cost-benefit models show some conflicting information, indicating that the increased performance may not offset the additional cost of achieving that performance.

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Oyenan, Walamitien Hervé. "An algebraic framework for compositional design of autonomous and adaptive multiagent systems." Diss., Kansas State University, 2010. http://hdl.handle.net/2097/3869.

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Doctor of Philosophy Department of Computing and Information Sciences Scott A. DeLoach Organization-based Multiagent Systems (OMAS) have been viewed as an effective paradigm for addressing the design challenges posed by today’s complex systems. In those systems, the organizational perspective is the main abstraction, which provides a clear separation between agents and systems, allowing a reduction in the complexity of the overall system. To ease the development of OMAS, several methodologies have been proposed. Unfortunately, those methodologies typically require the designer to handle system complexity alone, which tends to lead to ad-hoc designs that are not scalable and are difficult to maintain. Moreover, designing organizations for large multiagent systems is a complex and time-consuming task; design models quickly become unwieldy and thus hard to develop. To cope with theses issues, a framework for organization-based multiagent system designs based on separation of concerns and composition principles is proposed. The framework uses category theory tools to construct a formal composition framework using core models from the Organization-based Multiagent Software Engineering (O-MASE) framework. I propose a formalization of these models that are then used to establish a reusable design approach for OMAS. This approach allows designers to design large multiagent organizations by reusing smaller composable organizations that are developed separately, thus providing them with a scalable approach for designing large and complex OMAS. In this dissertation, the process of formalizing and composing multiagent organizations is discussed. In addition, I propose a service-oriented approach for building autonomous, adaptive multiagent systems. Finally, as a proof of concept, I develop two real world examples from the domain of cooperative robotics and wireless sensor networks.

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Davis, Cledo L. "The systems integration of autonomous behavior analysis to create a "Maritime Smart Environment" for the enhancement of maritime domain awareness." Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun%5FDavis.pdf.

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Thesis (M.S. in Systems Engineering)--Naval Postgraduate School, June 2010. Thesis Advisor(s): Goshorn, Rachel ; Goshorn, Deborah. "June 2010." Description based on title screen as viewed on June 24, 2010. Author(s) subject terms: Anomaly Detection, Artificial Intelligence, Automation, Behavior Analysis, Distributed Artificial Intelligence, Intelligence-Surveillance-Reconnaissance, Maritime Domain Awareness, Maritime Force Protection, Multi-agent Systems, Network-centric Operations, Network-centric Systems Engineering, Network-centric Warfare, Smart Sensor Networks, Systems Engineering, Systems Integration, System of Systems. Includes bibliographical references (p. 209-212). Also available in print.

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Seppecher, Pascal. "Modélisation multi-agents d'une économie monétaire de production : un système dynamique et complexe d'interactions réelles et monétaires entre des agents multiples, hétérogènes, autonomes et concurrents." Phd thesis, Université de Nice Sophia-Antipolis, 2011. http://tel.archives-ouvertes.fr/tel-00693151.

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Nous présentons un modèle numérique d'économie de marché décentralisée, fonctionnant hors de l'équilibre, composée de deux grands groupes d'agents (entreprises et ménages) auxquels sont respectivement associées deux fonctions économiques principales (production et consommation). Ces fonctions s'exercent dans le respect des règles des économies capitalistes (propriété privée des moyens de production, échanges monétaires, salariat). Les agents sont des individus en interaction directe et indirecte (et non des agents représentatifs ou des agrégats), chacun poursuivant son propre but, agissant en fonction de son état individuel et de l'environnement proche, sans se préoccuper du tout de l'équilibre général du système et sans contrôle supérieur (ni de la part d'un planificateur, ni d'un commissaire-priseur). Le modèle respecte les trois principes essentiels des économies monétaires: - le processus de production prend du temps et les entreprises ont besoin de crédit pour lancer ce processus; - la monnaie est endogène, elle est créée par le crédit bancaire à la production; - les entreprises sont guidées par le motif de profit et ce profit est monétaire. Implémenté en Java, le modèle se présente comme un laboratoire virtuel permettant de conduire de véritables expériences "in silico". Les interactions réelles et monétaires entre les agents (multiples, hétérogènes, autonomes et concurrents) forment un système dynamique et complexe dont les propriétés macroéconomiques ne sont pas postulées. Nous reconstruisons ainsi les conditions de l'émergence de comportements macroéconomiques inobservables dans les modèles basés sur les notions d'agent représentatif et d'équilibre général.

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Seelam, Aruntej. "REORGANIZATION OF MASSIVE MULTIAGENT SYSTEMS: MOTL/O." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1966550041&sid=3&Fmt=2&clientId=1509&RQT=309&VName=PQD.

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Oyenan, Walamitien Hervé. "An algebraic framework for compositional design of autonomous and adaptive multiagent systems." Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3869.

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Jarne, Ornia Daniel. "Ant Colony Algorithms andits applications to Autonomous Agents Systems." Thesis, KTH, Optimeringslära och systemteori, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-217391.

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With the latest advancements in autonomous agents systems and technology, there is a growing interest in developing control algorithms and methods to coordinate large numbers of robotic entities. Following this line of work, the use of biologically inspired algorithms based on swarm emerging behaviour presents some really interesting properties for controlling multiple agents. They rely on very simple instructions and communications to develop a coordinated structure in the system. Particularly, this master thesis focuses on the study of Ant Colony algorithms based on stigmergy interaction to coordinate agents and perform a certain task. The first part focuses on the theoretical background and algorithm convergence proof, while the second part consists of experimental simulations and results. For this, some metric parameters have been developed and found to be especially useful in the study of a simple path planning test case. The main concept developed in this work is an adaptation of Shannon Entropy that measures uniformity and order in the system and the weighted graph. This parameter has been used to study the performance and results of an autonomous agent system based on Ant Colony algorithms. Finally, this control algorithm has been modified to develop an event-triggered control scheme. Using the properties of the weighted graph (Entropy) and the sensing of the agents, a decentralized event-triggered method has been implemented and tested, and has been found to increase efficiency in the usage of system resources. Med den senaste tidens utveckling inom autonoma agentsystem och teknologier, finns ett ökat intresse för utveckling av styralgoritmer och metoder för att koordinera stora mängder robotenheter. Inom detta område visar användandet av biologiskt inspirerade algoritmer, baserade på naturliga svärmbeteenden, intressanta egenskaper som kan utnyttjas i styrandet av system som innefattar ett flertal agenter. Dessa är uppbyggda av simpla instruktioner och kommunikationsmedel för att tillgodose struktur i systemet. I synnerhet fokuserar detta masterexamensarbete på studier av Ant Colony-algoritmer, baserade på stigmergy-interaktion för att koordinera enheter och få dem att utföra specifika uppgifter. Den första delen behandlar den teoretiska bakgrunden och konvergensbevis medan den andra delen i huvudsak består av experimentella simuleringar samt resultat. Till detta ändamål har metriska parametrar utvecklats, vilka ansågs särskilt användbara när planeringen av en enkel bana studerades. Huvudkonceptet som utvecklats i detta arbete är en tillämpning av Shannon- Entropi, vilket mäter enhetlighet och ordning i ett system samt den viktade grafen. Denna parameter har använts för att studera prestandan och resultaten hos ett autonomt agentsystem baserat på Ant Colony-algoritmer. Slutligen har denna styralgoritm modifierats för att utveckla ett händelsestyrt styrschema. Genom att använda egenskaperna hos den viktade grafen (entropi) tillsammans med sensorsystemet hos agentenheterna, så har en decentraliserad händelsestyrd metod implementerats, testats och visat sig ge ökad effektivitet gällande utnyttjandet av systemresurser.

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AL-Buraiki, Omar S. M. "Specialized Agents Task Allocation in Autonomous Multi-Robot Systems." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41504.

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With the promise to shape the future of industry, multi-agent robotic technologies have the potential to change many aspects of daily life. Over the coming decade, they are expected to impact transportation systems, military applications such as reconnaissance and surveillance, search-and-rescue operations, or space missions, as well as provide support to emergency first responders. Motivated by the latest developments in the field of robotics, this thesis contributes to the evolution of the future generation of multi-agent robotic systems as they become smarter, more accurate, and diversified in terms of applications. But in order to achieve these goals, the individual agents forming cooperative robotic systems need to be specialized in what they can accomplish, while ensuring accuracy and preserving the ability to perform diverse tasks. This thesis addresses the problem of task allocation in swarm robotics in the specific context where specialized capabilities of the individual agents are considered. Based on the assumption that each individual agent possesses specialized functional capabilities and that the expected tasks, which are distributed in the surrounding environment, impose specific requirements, the proposed task allocation mechanisms are formulated in two different spaces. First, a rudimentary form of the team members’ specialization is formulated as a cooperative control problem embedded in the agents’ dynamics control space. Second, an advanced formulation of agents’ specialization is defined to estimate the individual agents’ task allocation probabilities in a dedicated specialization space, which represents the core contribution of this thesis to the advancement and practice in the area of swarm robotics. The original task allocation process formulated in the specialization space evolves through four stages of development. First, a task features recognition stage is conceptually introduced to leverage the output of a sensing layer embedded in robotic agents to drive the proposed task allocation scheme. Second, a matching scheme is developed to best match each agent’s specialized capabilities with the corresponding detected tasks. At this stage, a general binary definition of agents’ specialization serves as the basis for task-agent association. Third, the task-agent matching scheme is expanded to an innovative probabilistic specialty-based task-agent allocation framework to generalize the concept and exploit the potential of agents’ specialization consideration. Fourth, the general framework is further refined with a modulated definition of the agents’ specialization based on their mechanical, physical structure, and embedded resources. The original framework is extended and a prioritization layer is also introduced to improve the system’s response to complex tasks that are characterized based on the recognition of multiple classes. Experimental validation of the proposed specialty-based task allocation approach is conducted in simulation and on real-world experiments, and the results are presented and discussed in light of potential applications to demonstrate the effectiveness and efficiency of the proposed framework.

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Hess, Traci J. "A Study of Autonomous Agents in Decision Support Systems." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/11277.

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Software agents have been heralded as the most important emerging technology of the decade. As software development firms eagerly attempt to integrate these autonomous programs into their products, researchers attempt to define the concept of agency and to develop architectures that will improve agent capabilities. Decision Support System (DSS) researchers have been eager to integrate agents into their applications, and exploratory works in which agents have been used within a DSS have been documented. This dissertation attempts to further this exploration by studying the agent features and underlying architectures that can lead to the successful integration of agents in DSS. This exploration is carried out in three parts. In the first part, a review of the relevant research streams is provided. The history and current status of software agents is first discussed. Similarly, a historical and current view of DSS research is provided. Lastly, a historical and tutorial-type of discussion is provided on the topic of Artificial Intelligence (AI) planning. This review of the relevant literature provides a general background for the conceptual analyses and implementations that are carried out in the next two sections. In the second part, the literature on software agents is synthesized to develop a definition of agency applicable to DSS. Using this definition, an agent-integrated DSS that supports variance-analysis is designed and developed. Following this implementation, a general framework for agent-enabling DSS is suggested. The use of this framework promises to raise some DSS to a new level of capability whereby "what-if" systems are transformed into real-time, proactive systems. The third part utilizes this general framework to agent-enable a corporate-planning system DSS and extends the framework in the second section through the introduction of an automated-planning agent. The agent uses AI planning to generate decision-making alternatives, providing a means to integrate and sequence the models in the DSS. The architecture used to support this planning agent is described. This new kind of DSS enables not only the monitoring of goals, but also the maintenance of these goals through agent-generated plans. The conclusion summarizes the contributions of this work and outlines in considerable detail potential research opportunities in the realm of software agents, DSS, and planning. Ph. D.

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Khan, Majid Ali. "Coalition formation and teamwork in embodied agents." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2711.

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Embodied agents are agents acting in the physical world, such as persons, robots, unmanned air or ground vehicles and so on. These types of agents are subject to spatio-temporal constraints, which do not exist for agents acting in a virtual environment. The movement of embodied agents is limited by obstacles and maximum velocity, while their communication is limited by the transmission range of their wireless devices. This dissertation presents contributions to the techniques of coalition formation and teamwork coordination for embodied agents. We considered embodied agents in three different settings, each of them representative of a class of practical applications. First, we study coalition formation in the one dimensional world of vehicles driving on a highway. We assume that vehicles can communicate over short distances and carry agents which can advise the driver on convoy formation decisions. We introduce techniques which allow vehicles to influence the speed of the convoys, and show that this yields convoys which have a higher utility for the participating vehicles. Second, we address the problem of coalition formation in the two dimensional world. The application we consider is a disaster response scenario. The agents are forming coalitions through a multi-issue negotiation with spatio-temporal components where the coalitions maintain a set of commitments towards participating agents. Finally, we discuss a scenario where embodied agents form coalitions to optimally address dynamic, non-deterministic, spatio-temporal tasks. The application we consider is firefighters acting in a disaster struck city. Ph.D. School of Electrical Engineering and Computer Science Engineering and Computer Science Computer Engineering PhD

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Meshref, Hossam. "Modeling Autonomous Agents' Behavior Using Neuro-Immune Networks." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/28473.

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Autonomous robots are expected to interact with their dynamic changing environment. This interactions requires certain level of behavior based Intelligence, which facilitates the dynamic adaptation of the robot behavior accordingly with his surrounding environment. Many researches have been done in biological information processing systems to model the behavior of an autonomous robot. The Artificial Immune System (AIS) provides new paradigm suitable for dynamic problem dealing with unknown environment rather than a static problem. The immune system has some features such as memory, tolerance, diversity and more features that can be used in engineering applications. The immune system has an important feature called meta-dynamics in which new species of antibodies are produced continuously from the bone marrow. If the B-Cell (robot) cannot deal with the current situation, new behaviors (antibodies) should be generated by the meta dynamics function. This behavior should be incorporated into the existing immune system to gain immunity against new environmental changes. We decided to use a feed forward Artificial Neural Network (ANN) to simulate this problem, and to build the AIS memory. Many researchers have tried to tackle different points in mimicking the biological immune system, but no one previously has proposed such an acquired memory. This contribution is made as a "proof of concept" to the field of biological immune system simulation as a start of further research efforts in this direction. Many applications can potentially use our designed Neuro-Immune Network (NIN), especially in the area of autonomous robotics. We demonstrated the use of the designed NIN to control a robot arm in an unknown environment. As the system encounters new cases, it will increase its ability to deal with old and new situations encountered. This novel technique can be applied to many robotics applications in industry, where autonomous robots are required to have adaptive behavior in response to their environmental changes. Regarding future work, the use of VLSI neural networks to enhance the speed of the system for real time applications can be investigated along with possible methods of design and implementation of a similar VLSI chip for the AIN. Ph. D.

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Faratin, Peyman. "Automated service negotiation between autonomous computational agents." Thesis, Queen Mary, University of London, 2000. http://qmro.qmul.ac.uk/xmlui/handle/123456789/28945.

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Multi-agent systems are a new computational approach for solving real world, dynamic and open system problems. Problems are conceptualized as a collection of decentralised autonomous agents that collaborate to reach the overall solution. Because of the agents autonomy, their limited rationality, and the distributed nature of most real world problems, the key issue in multi-agent system research is how to model interactions between agents. Negotiation models have emerged as suitable candidates to solve this interaction problem due to their decentralised nature, emphasis on mutual selection of an action, and the prevalence of negotiation in real social systems. The central problem addressed in this thesis is the design and engineering of a negotiation model for autonomous agents for sharing tasks and/or resources. To solve this problem a negotiation protocol and a set of deliberation mechanisms are presented which together coordinate the actions of a multiple agent system. In more detail, the negotiation protocol constrains the action selection problem solving of the agents through the use of normative rules of interaction. These rules temporally order, according to the agents' roles, communication utterances by specifying both who can say what, as well as when. Specifically, the presented protocol is a repeated, sequential model where offers are iteratively exchanged. Under this protocol, agents are assumed to be fully committed to their utterances and utterances are private between the two agents. The protocol is distributed, symmetric, supports bi and/or multi-agent negotiation as well as distributive and integrative negotiation. In addition to coordinating the agent interactions through normative rules, a set of mechanisms are presented that coordinate the deliberation process of the agents during the ongoing negotiation. Whereas the protocol normatively describes the orderings of actions, the mechanisms describe the possible set of agent strategies in using the protocol. These strategies are captured by a negotiation architecture that is composed of responsive and deliberative decision mechanisms. Decision making with the former mechanism is based on a linear combination of simple functions called tactics, which manipulate the utility of deals. The latter mechanisms are subdivided into trade-off and issue manipulation mechanisms. The trade-off mechanism generates offers that manipulate the value, rather than the overall utility, of the offer. The issue manipulation mechanism aims to increase the likelihood of an agreement by adding and removing issues into the negotiation set. When taken together, these mechanisms represent a continuum of possible decision making capabilities: ranging from behaviours that exhibit greater awareness of environmental resources and less to solution quality, to behaviours that attempt to acquire a given solution quality independently of the resource consumption. The protocol and mechanisms are empirically evaluated and have been applied to real world task distribution problems in the domains of business process management and telecommunication management. The main contribution and novelty of this research are: i) a domain independent computational model of negotiation that agents can use to support a wide variety of decision making strategies, ii) an empirical evaluation of the negotiation model for a given agent architecture in a number of different negotiation environments, and iii) the application of the developed model to a number of target domains. An increased strategy set is needed because the developed protocol is less restrictive and less constrained than the traditional ones, thus supporting development of strategic interaction models that belong more to open systems. Furthermore, because of the combination of the large number of environmental possibilities and the size of the set of possible strategies, the model has been empirically investigated to evaluate the success of strategies in different environments. These experiments have facilitated the development of general guidelines that can be used by designers interested in developing strategic negotiating agents. The developed model is grounded from the requirement considerations from both the business process management and telecommunication application domains. It has also been successfully applied to five other real world scenarios.

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Baltrusch, Rob. "Hybrid Multiagent Systems: Intelligent Agile Oriented Architectures for Enterprise Integration." Thesis, Griffith University, 2007. http://hdl.handle.net/10072/366265.

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This research defines the business requirements for forming a Network capable of instantiating Virtual Enterprises (VEs); investigates the current state of the art for enterprise and Information and Communication Technology (ICT) architectures; and develops an improved intelligent software architecture for managing a dynamic, VE-forming Network of Partners. What is lacking in the current body of knowledge are methodologies and reusable partial models for how to specify and design ICT architectures that support complex coordination in an agile and intelligent manner. There is no generic method or comprehensive architecture today which would give businesses the ability to build and maintain such collaboration in a dynamically changing virtual enterprise. This problem is particularly evident in one-of-a-kind production, because the VEs must be created every time a large project is undertaken. Enterprises need to remain competitive by developing products which are specific to individual requirements, and developed globally to leverage resources. This research proposes that an enterprise can be represented as a set of hybrid, flexible, autonomous agents which encapsulate decision centres and other resources in order to execute business functions. The goal of this research is to define and develop an improved software architecture which supports globally distributed functional and resource management. The proposed ICT architecture will be developed and demonstrated using state-of-the-art protocols and platforms. The focus is on supporting: intelligent and agile interaction with customers and other Network stakeholders optimisation of the supply chain through collaboration and reasoning integrating heterogenous information and human activity systems The research objectives are to answer the following questions: 1. What are the business requirements, design parameters and design constraints for managing a dynamic, VE-forming Network of Partners? 2. Based on this design space, how can suitable supporting software architectures be specified? 3. Is the developed hypothesis valid? The fundamental research hypotheses are: 1. a VE-forming Network of Partners can be designed as a multiagent system of hybrid agents 2. such a design can be implemented using current protocols and platforms The research specifies and validates the architectural design of the Agile-Oriented Architecture, which contains several important design attributes currently not present in any of the current ICT architectures. Thesis (PhD Doctorate) Doctor of Philosophy (PhD) School of Information and Communication Technology Full Text

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Chau, Wan-hin Derek, and 鄒允軒. "Modeling and solving decentralized supply chain management problems using multi-agent system with dynamic-control agents." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2015. http://hdl.handle.net/10722/208622.

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Managing large scale supply chains are never an easy task. Numerous researches have put emphasis on supply chain modeling and optimization to assist businesses in searching for the best practices so as to endure the extremely competitive business landscape. To some, the paradigm of centralized supply chain management is adequate for solving its strategic and operational problems. Yet with the improper use of authoritative assumptions, the efficiency of the management process is often jeopardized. Furthermore, current researches in decentralized supply chain are mostly focused on dyadic or linear relationship and seldom consider quantitative modeling and analysis with scalability. Recent development in multi-agent systems provided a means for such a modeling methodology and hence researches in this area. To enhance model representativeness and computational efficiency, vision-based control models that are able to simulate individual operational and strategic traits are developed. In this research, pyramidal agent alignment is proposed for simulating the management-operation dimension with regards to decision exercising and bargaining power management. The system offers one thousand supply chain agents that are simulated in a mono-layer, multi-tier network in real time. Stochastic and dynamic behaviors of the network are handled by statistical regression on scenario-based model evaluation. The proposed design enabled grand scale supply chain modeling and optimization that follows a general or custom simulation supported optimization architecture. Network governance problems and dynamic steering problems are considered and solved using genetic algorithm and dynamic programming. The thesis looks into the potential benefits and limitations of the proposed methods in details, and future research directions are discussed. published_or_final_version Industrial and Manufacturing Systems Engineering Doctoral Doctor of Philosophy

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Troquard, Nicolas. "Independent agents in branching time : towards a unified framework for reasoning about multiagent systems." Toulouse 3, 2007. http://www.theses.fr/2007TOU30119.

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Le travail présenté dans cette thèse est une étude multidisciplinaire de le notion de réalisation (`agency'). Nous construisons de nouvelles approches formelles à partir de la littérature de la réalisation en philosophie de l'action, théorie des jeux ou informatique. Nous cherchons particulièrement à confronter les différentes logiques issues de traditions diverses, et à transférer entre elles leurs résultats et méthodes respectifs. La théorie du STIT de Belnap et Perloff est notre cadre d'expérimentation The work presented in this thesis is a multidisciplinary study of the notion of agency. We build new formal approaches starting on the literature of agency in philosophy of action, game theory or computer science. Belnap and Perloff's STIT theory is our frame of experimentation. This is a logic that stems from philosophy of action based on the observation that an action can be identi_ed with what it brings about. In this tradition, the sentence. Ishmael sails on board the Pequod. Will be paraphrased by. Ishmael sees to it that Ishmael sails on board the Pequod. . Our first contribution is to simplify the axiomatics of a version of the logic restrained to individual agency and without temporal aspects. This allows us to simplify the semantics of STIT as well as to discover a link with product logics. We establish the NEXPTIME-completeness of the problem of satisfiability. We capitalize on the simplifications and extend the axiomatization to coalitional actions. We show that we can embed Coalition Logic in the resulting logic. We also provide an epistemic extension and use it to tackle the problem of epistemically uniform strategies. Then we study further the temporal aspects of agency. We first do it by way of a logic combining STIT with a dynamic logic providing actions with duration, that can be deliberatively continued or aborted along time. We then give an embedding of Alternating-time Temporal Logic in a slightly adapted strategic STIT logic. Having developed a neat understanding of relevant structures of agency, we propose a fine-grained ontology of action and agency

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White, Alan Gordon. "CAMP-BDI : an approach for multiagent systems robustness through capability-aware agents maintaining plans." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/31465.

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Rational agent behaviour is frequently achieved through the use of plans, particularly within the widely used BDI (Belief-Desire-Intention) model for intelligent agents. As a consequence, preventing or handling failure of planned activity is a vital component in building robust multiagent systems; this is especially true in realistic environments, where unpredictable exogenous change during plan execution may threaten intended activities. Although reactive approaches can be employed to respond to activity failure through replanning or plan-repair, failure may have debilitative effects that act to stymie recovery and, potentially, hinder subsequent activity. A further factor is that BDI agents typically employ deterministic world and plan models, as probabilistic planning methods are typical intractable in realistically complex environments. However, deterministic operator preconditions may fail to represent world states which increase the risk of activity failure. The primary contribution of this thesis is the algorithmic design of the CAMP-BDI (Capability Aware, Maintaining Plans) approach; a modification of the BDI reasoning cycle which provides agents with beliefs and introspective reasoning to anticipate increased risk of failure and pro-actively modify intended plans in response. We define a capability meta-knowledge model, providing information to identify and address threats to activity success using precondition modelling and quantitative quality estimation. This also facilitates semantic-independent communication of capability information for general advertisement and of dependency information - we define use of the latter, within a structured messaging approach, to extend local agent algorithms towards decentralized, distributed robustness. Finally, we define a policy based approach for dynamic modification of maintenance behaviour, allowing response to observations made during runtime and with potential to improve re-usability of agents in alternate environments. An implementation of CAMP-BDI is compared against an equivalent reactive system through experimentation in multiple perturbation configurations, using a logistics domain. Our empirical evaluation indicates CAMP-BDI has significant benefit if activity failure carries a strong risk of debilitative consequence.

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Case, Denise Marie. "Engineering complex systems with multigroup agents." Diss., Kansas State University, 2015. http://hdl.handle.net/2097/19045.

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Doctor of Philosophy Computing and Information Sciences Scott A. DeLoach As sensor prices drop and computing devices continue to become more compact and powerful, computing capabilities are being embedded throughout our physical environment. Connecting these devices in cyber-physical systems (CPS) enables applications with significant societal impact and economic benefit. However, engineering CPS poses modeling, architecture, and engineering challenges and, to fully realize the desired benefits, many outstanding challenges must be addressed. For the cyber parts of CPS, two decades of work in the design of autonomous agents and multiagent systems (MAS) offers design principles for distributed intelligent systems and formalizations for agent-oriented software engineering (AOSE). MAS foundations offer a natural fit for enabling distributed interacting devices. In some cases, complex control structures such as holarchies can be advantageous. These can motivate complex organizational strategies when implementing such systems with a MAS, and some designs may require agents to act in multiple groups simultaneously. Such agents must be able to manage their multiple associations and assignments in a consistent and unambiguous way. This thesis shows how designing agents as systems of intelligent subagents offers a reusable and practical approach to designing complex systems. It presents a set of flexible, reusable components developed for OBAA++, an organization-based architecture for single-group MAS, and shows how these components were used to develop the Adaptive Architecture for Systems of Intelligent Systems (AASIS) to enable multigroup agents suitable for complex, multigroup MAS. This work illustrates the reusability and flexibility of the approach by using AASIS to simulate a CPS for an intelligent power distribution system (IPDS) operating two multigroup MAS concurrently: one providing continuous voltage control and a second conducting discrete power auctions near sources of distributed generation.

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Sendi, Naziha. "Transparent approach based on deep learning and multiagent argumentation for hypertension management." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASG036.

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L'hypertension est connue pour être l'une des principales causes de maladies cardiaques et d'accidents vasculaires cérébraux, tuant environ 7,5 millions de personnes dans le monde chaque année, principalement en raison de son diagnostic tardif.Afin de confirmer le diagnostic d'hypertension, il est nécessaire de collecter des mesures médicales répétées. Une solution consiste à exploiter ces mesures et à les intégrer dans les dossiers électroniques de santé par des algorithmes d'apprentissage automatique.Dans ce travail, nous nous sommes concentrés sur les méthodes d'ensemble qui combinent plusieurs algorithmes d'apprentissage automatique pour la classification. Ces modèles ont été largement utilisés pour améliorer les performances de classification d'un seul classificateur. Pour cela, des méthodes telles que Bagging et Boosting sont utilisées. Ces méthodes utilisent principalement le vote majoritaire ou pondéré pour intégrer les résultats des classificateurs. Cependant, un inconvénient majeur de ces approches est leur opacité, car elles ne fournissent pas d'explication des résultats et ne permettent pas une intégration préalable des connaissances. Comme nous utilisons l'apprentissage automatique pour les soins de santé, l'explication des résultats de classification et la possibilité d'introduire des connaissances de domaine et cliniques dans le modèle appris deviennent une nécessité.Afin de pallier ces faiblesses, nous introduisons une nouvelle méthode d'ensemble basée sur l'argumentation multiagents.L'intégration de l'argumentation et de l'apprentissage automatique s'est avérée fructueuse et l'utilisation de l'argumentation est un moyen pertinent de combiner les classificateurs. En effet, l'argumentation peut imiter le processus décisionnel humain pour réaliser la résolution des conflits.Notre idée est d'extraire automatiquement les arguments des modèles ML et de les combiner à l'aide de l'argumentation. Cela permet d'exploiter les connaissances internes de chaque classifieur, de fournir une explication des décisions et de faciliter l'intégration des connaissances du domaine.Dans cette thèse, les objectifs étaient multiples. Du point de vue de l'application médicale, l'objectif était de prédire le traitement de l'hypertension et la date de la prochaine visite chez le médecin. D'un point de vue scientifique, l'objectif était d'ajouter de la transparence à la méthode d'ensemble et d'injecter des connaissances du domaine.Les contributions de la thèse sont diverses:-Explication des prédictions;-Intégration des connaissances internes de classification;-Injection des connaissances du domaine;-Amélioration de la précision des prédictions.Les résultats démontrent que notre méthode fournit efficacement des explications et de la transparence des prédictions des méthodes d'ensemble et est capable d'intégrer le domaine et les connaissances cliniques dans le système. De plus, il améliore les performances des algorithmes d'apprentissage automatique existants Hypertension is known to be one of the leading causes of heart disease and stroke, killing around 7.5 million people worldwide every year, mostly because of its late diagnosis.In order to confirm the diagnosis of Hypertension, it is necessary to collect repeated medical measurements. One solution is to exploit these measurements and integrate them into Electronic Health Records by Machine Learning algorithms.In this work, we focused on ensemble learning methods that combine several machine learning algorithms for classification. These models have been widely used to improve classification performance of a single classifier. For that purpose, methods such as Bagging and Boosting are used. These methods mainly use majority or weighted voting to integrate the results of the classifiers. However, one major drawback of these approaches is their opacity, as they do not provide results explanation and they do not allow prior knowledge integration. As we use machine learning for healthcare, the explanation of classification results and the ability to introduce domain and clinical knowledge inside the learned model become a necessity.In order to overcome theses weaknesses, we introduce a new ensemble method based on multiagent argumentation.The integration of argumentation and machine learning has been proven to be fruitful and the use of argumentation is a relevant way for combining the classifiers. Indeed, argumentation can imitate human decision-making process to realize resolution of the conflicts.Our idea is to automatically extract the arguments from ML models and combine them using argumentation. This allows to exploit the internal knowledge of each classifier, to provide an explanation for the decisions and to facilitate integration of domain and clinical knowledge.In this thesis, objectives were multiple. From the medical application point of view, the goal was to predict the treatment of Hypertension and the date of the next doctor visit. From the scientific point of view, the objective was to add transparency to ensemble method and to inject domain and clinical knowledge.The contributions of the thesis are various:-Explaining predictions;-Integrating internal classification knowledge;-Injecting domain and clinical knowledge;-Improving predictions accuracy.The results demonstrate that our method effectively provides explanations and transparency of the ensemble methods predictions and is able to integrate domain and clinical knowledge into the system. Moreover, it improves the performance of existing machine learning algorithms

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Derakhshan, Farnaz. "The implementation of dynamic assignment of rights, responsibilities and sanctions to external agents in normative multiagent systems." Thesis, University of Liverpool, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494086.

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Recently, the design and development of multiagent systems (MASs) has become increasingly concerned with the recognition that they will be used in a dynamic and open environment. In such environments, it is a very difficult and complicated task to anticipate all possible runtime situations at design time. Therefore, in order to respond to changes in this environment it is necessary to allow the system to provide dynamic responses at runtime. This thesis is concerned with one particular aspect of such responses. Our novel contribution is that we explicitly identify clarify and address the problem of dynamic assignment of rights, responsibilities (R&Rs) and sanctions to external agents in normative MASs.

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Casals, Arthur. "Smart Mobility. An approach using multiagent planning and coordination." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS063.

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Dans cette thèse, nous proposons une approche auto-adaptative pour construire un système intelligent de gestion des feux de circulation à utiliser dans les intersections. Cette approche s'appuie sur l'architecture des systèmes multi-agents (MAS) et le paradigme de l'agent BDI pour modéliser, concevoir et mettre en œuvre un SMA pour le contrôle du trafic capable de prendre en charge un mécanisme de régulation distribué et collaboratif tout en tenant compte des changements dynamiques du flux de trafic. Nos recherches concernent les domaines des systèmes sensibles au contexte, des agents intelligents, des systèmes multi-agents, de la planification collaborative entre agents, des architectures distribuées, du raisonnement contextuel et de l'intelligence ambiante. Nos contributions incluent un modèle général pour l'augmentation contextuelle des agents intelligents, un mécanisme de planification collaborative pour les agents contextuels et un cadre pour fournir la planification des agents en tant que service dans des architectures distribuées et faiblement couplées. Ce travail, lorsqu'il est combiné, aboutit à un agent collaboratif apte à être utilisé dans des scénarios impliquant la gestion et le contrôle des feux de circulation. Nos expériences cumulées, ainsi que l'évolution de notre architecture d'agents, aboutissent à un SMA qui permet aux agents d'optimiser la réalisation de leurs intentions individuelles et est capable de s'appuyer sur des processus auxiliaires tels que l'apprentissage automatique pour améliorer la qualité globale du système. Notre approche est validée par des expériences localisées, des simulations et des expériences reflétant des scénarios du monde réel In this thesis, we propose a self-adaptive approach to build a smart traffic light management system to be used in intersections. This approach relies on the multiagent systems (MAS) architecture and the BDI agent paradigm to model, design, and implement a MAS for traffic control able to support a distributed and collaborative regulation mechanism while taking into account dynamic changes in the traffic flow. Our research involves the domains of context-aware systems, intelligent agents, multiagent systems, collaborative planning among agents, distributed architectures, contextual reasoning, and ambient intelligence. Our contributions include a general model for intelligent agents contextual augmentation, a collaborative planning mechanism for contextual agents, and a framework to provide agent planning as a service in distributed, loosely-coupled architectures. This work, when combined, results in a collaborative agent apt to be used in scenarios involving management and control of traffic lights. Our cumulative experiments, together with the evolution of our agent architecture, result in a MAS that (i) allows the agents to optimize the realization of their individual intentions and (ii) is able to rely on auxiliary processes such as machine learning (reinforcement learning) to improve the overall quality of the system. Our complete approach is validated by localized experiments, simulations, and experiments reflecting real-world scenarios

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Casali, Ana. "On intentional and social agents with graded attitudes." Doctoral thesis, Universitat de Girona, 2008. http://hdl.handle.net/10803/7748.

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La principal contribución de esta Tesis es la propuesta de un modelo de agente BDI graduado (g-BDI) que permita especificar una arquitetura de agente capaz de representar y razonar con actitudes mentales graduadas. Consideramos que una arquitectura BDI más exible permitirá desarrollar agentes que alcancen mejor performance en entornos inciertos y dinámicos, al servicio de otros agentes (humanos o no) que puedan tener un conjunto de motivaciones graduadas. En el modelo g-BDI, las actitudes graduadas del agente tienen una representación explícita y adecuada. Los grados en las creencias representan la medida en que el agente cree que una fórmula es verdadera, en los deseos positivos o negativos permiten al agente establecer respectivamente, diferentes niveles de preferencias o de rechazo. Las graduaciones en las intenciones también dan una medida de preferencia pero en este caso, modelan el costo/beneficio que le trae al agente alcanzar una meta. Luego, a partir de la representación e interacción de estas actitudes graduadas, pueden ser modelados agentes que muestren diferentes tipos de comportamiento. La formalización del modelo g-BDI está basada en los sistemas multi-contextos. Diferentes lógicas modales multivaluadas se han propuesto para representar y razonar sobre las creencias, deseos e intenciones, presentando en cada caso una axiomática completa y consistente. Para tratar con la semántica operacional del modelo de agente, primero se definió un calculus para la ejecución de sistemas multi-contextos, denominado Multi-context calculus. Luego, mediante este calculus se le ha dado al modelo g-BDI semántica computacional. Por otra parte, se ha presentado una metodología para la ingeniería de agentes g-BDI en un escenario multiagente. El objeto de esta propuesta es guiar el diseño de sistemas multiagentes, a partir de un problema del mundo real. Por medio del desarrollo de un sistema recomendador en turismo como caso de estudio, donde el agente recomendador tiene una arquitectura g-BDI, se ha mostrado que este modelo es valioso para diseñar e implementar agentes concretos. Finalmente, usando este caso de estudio se ha realizado una experimentación sobre la flexibilidad y performance del modelo de agente g-BDI, demostrando que es útil para desarrollar agentes que manifiesten conductas diversas. También se ha mostrado que los resultados obtenidos con estos agentes recomendadores modelizados con actitudes graduadas, son mejores que aquellos alcanzados por los agentes con actitudes no-graduadas. The central contribution of this dissertation is the proposal of a graded BDI agent model (g-BDI), specifying an architecture capable of representing and reasoning with graded mental attitudes. We consider that making the BDI architecture more exible will allow us to design and develop agents capable of improved performance in uncertain and dynamic environments, serving other agents (human or not) that may have a set of graded motivations. In the g-BDI model, the agent graded attitudes have an explicit and suitable representation. Belief degrees represent the extent to which the agent believes a formula to be true. Degrees of positive or negative desires allow the agent to set di_erent levels of preference or rejection respectively. Intention degrees also give a preference measure but, in this case, modelling the cost/benefit trade off of achieving an agent's goal. Then, agents having different kinds of behaviour can be modelled on the basis of the representation and interaction of their graded attitudes. The formalization of the g-BDI agent model is based on Multi-context systems and in order to represent and reason about the beliefs, desires and intentions, we followed a many-valued modal approach. Also, a sound and complete axiomatics for representing each graded attitude is proposed. Besides, in order to cope with the operational semantics aspects of the g-BDI agent model, we first defined a Multi-context calculus for Multi-context systems execution and then, using this calculus we give this agent model computational meaning. Furthermore, a software engineering process to develop graded BDI agents in a multiagent scenario is presented. The aim of the proposed methodology is to guide the design of a multiagent system starting from a real world problem. Through the development of a Tourism recommender system, where one of its principal agents is modelled as a g-BDI agent, we show that the model is useful to design and implement concrete agents. Finally, using the case study we have made some experiments concerning the exibility and performance of the g-BDI agent model, demonstrating that this agent model is useful to develop agents showing varied and rich behaviours. We also show that the results obtained by these particular recommender agents using graded attitudes improve those achieved by agents using non-graded attitudes.

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Frozza, Rejane. "Simula : ambiente para desenvolvimento de sistemas multiagentes reativos." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 1997. http://hdl.handle.net/10183/17923.

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Sistema multiagente é um tema de estudo em IAD, no qual um conjunto de agentes interage em um ambiente comum. A IAD baseia-se no comportamento social de agentes (humanos e artificiais), enfatizando as ações e as interações dos mesmos. Esses agentes podem ser cognitivos ou reativos. Os sistemas multiagentes reativos têm sido usados em pesquisas e estudos ligados a campos importantes de aplicação, gerando o desenvolvimento de sistemas não apenas para a área acadêmica, mas também para atender às necessidades do mercado industrial. Com o objetivo de abranger um ramo de pesquisas em sistemas multiagentes, este trabalho propôs a definição e a implementação de um protótipo de um ambiente de software que possibilita o desenvolvimento de aplicações em sistemas multiagentes reativos. Este ambiente tem a finalidade de facilitar a criação de tais aplicações com o uso de agentes, atingindo um resultado satisfatório. O ambiente definido é o SIMULA, que possibilita ao usuário criar suas aplicações através de elementos de uma interface gráfica. O usuário, na interação com o ambiente, determina os agentes envolvidos no problema e como eles agirão no processo de resolução do mesmo. O usuário define a sua aplicação criando um modelo para ela. Para definir as características do ambiente SIMULA, foram estudados e analisados três modelos de sistemas multiagentes reativos, encontrados em [STE 90], [DEM 93] e [FER 91], e estabelecido um quadro comparativo dos mesmos, segundo alguns critérios determinados. Esses modelos permitem que se faça a modelagem de aplicações nas quais o processo de resolução dos problemas, representados por tais aplicações, parece se adequar às características dos agentes reativos. A validação do uso do ambiente SIMULA envolveu a modelagem de três aplicações: a atuação de robôs na busca de minerais, definido em [STE 90], o jogo PENGI, definido em [AGR 87] e [FER 91], e a atuação de parasitas no controle de pragas de plantações. Esta última sendo uma novidade para a resolução com agentes reativos. Multiagent Systems is a subject of study in DAI (Distributed Artificial Intelligence) in which a group of agents interacts with the same tool . DAI is based on social behavior of agents (human and artificial ones) focus on actions and interactions of them . Those agents can be cognitive or reactive . Reactive Multiagent Systems have been used in research and studies linked to important fields of use that generates the development of systems not only for academic areas but also to meet the needs of industrial market. As we have the objective of ranging a research field of multiagent systems, this work comes up with a definition and implementation of a prototype of a software tool which enables the application development in reactive multiagent system . This tool has the purpose to ease the creation of such applications like the use of agents and consequently achieving a satisfactory result . The tool is called SIMULA and it enables the user to create his own applications through elements from a graphic interface . The user who interacts with the tool determines the agents involved in the problem and how they will act in the process of solving this matter . Applications are developed based in models created by the user. In order to characterize the tool SIMULA , three models of reactive multiagent systems found in [STE 90] , [DEM 93] and [FER 91] have been studied and analyzed. A comparative table has been made according to definite criteria. These models allow shaping the applications in which the process of problem solving represented by such applications seems adequate to the characteristics of reactive agents . Validation of use of SIMULA tool involved modeling of three applications : performance of robots in mineral prospection defined in [STE 90] , PENGI game defined in [AGR 87] and [FER 91] and perfomance of parasite in controlling crop plagues that is being a novelty.

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Collins, N. M. "Towards autonomous agents for live computer music : realtime machine listening and interactive music systems." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597873.

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This thesis will describe a set of interactive systems developed for a range of musical styles and instruments, all of which attempt to participate in a concert by means of audio signal analysis alone. Machine listening, being the simulation of human peripheral auditory abilities, and the hypothetical modelling of central auditory and cognitive processes, is utilised in these systems to track musical activity. Whereas much of this modelling is inspired by a bid to emulate human abilities, strategies diverging from plausible human physiological mechanisms are often employed, leading to matching capabilities which exceed or differ from the human counterparts. Technology is described which detects events from an audio stream, further analysing the discovered events (typically notes) for perceptual features of loudness, pitch, attack time and timbre. In order to exploit processes that underlie common musical practice, beat tracking is investigated, allowing the inference of metrical structure which can act as a co-ordinative framework for interaction. Psychological experiments into human judgement of perceptual attack time and beat tracking to ecologically valid stimuli clarify the parameters and constructs that should most appropriately be instantiated in the computational systems. All the technology produced is intended for the demanding environment of realtime concert use. In particular, an algorithmic audio splicing and analysis library called BBCut2 is described, designed with appropriate processing and scheduling facilities for realtime operation. Proceeding to outlines of compositional applications, novel interactive music systems are introduced which have been tested in real concerts. These are evaluated by interviews with the musicians who performed with them, and an assessment of their claims to agency in the sense of ‘autonomous agents’. The thesis closes by considering all that has been built, and the possibilities for future advances allied to artificial intelligence and signal processing technology.

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Lutzhöft, Margareta. "Self-organised communication in autonomous agents: A critical evaluation of artificial life models." Thesis, University of Skövde, Department of Computer Science, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-485.

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This dissertation aims to provide a critical evaluation of artificial life (A-Life) models of communication in autonomous agents. In particular the focus will be on the issue of self-organisation, which is often argued to be one of the characteristic features distinguishing A-life from other approaches. To ground the arguments, a background of the study of communication within artificial intelligence is provided. This is followed by a comprehensive review of A-Life research on communication between autonomous agents, which is evaluated by breaking down self-organisation into the following sub-questions. Is communication self-organised or hard-coded? What do signals mean to the agents, and how should an external examiner interpret them? Is there any spatial or temporal displacement, or do agents only communicate about their present situation? It is shown that there is very little self-organised communication, as yet, when examined on these grounds, and that most models only look at communication as relatively independent from other behaviours. As a conclusion, it is suggested to use integrated co-evolution of behaviours, including communication, in the spirit of the enactive cognitive science paradigm, and by using incremental evolution combined with learning.

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Evans, Katherine. "The Implementation of Ethical Decision Procedures in Autonomous Systems : the Case of the Autonomous Vehicle." Thesis, Sorbonne université, 2021. http://www.theses.fr/2021SORUL003.

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Les problèmes éthiques liés à l’arrivée de formes d’intelligence artificielles différentes a sollicité beaucoup d’attention aussi bien académique que publique. Cependant, ces inquiétudes se concentrent sur un problème particulier : comment assurer que les décisions prises par les agents artificiels comme des voitures autonomes ne nuisent pas aux êtres humains présents dans leur environnement ? Cette question a incité la création de ceux qui sont communément appelés les agents moraux artificiels dans la littérature, la prise de décision desquels est contrainte par une moralité artificielle : un système de principes normatifs implémenté dans le processus de raisonnement de la machine. A ce jour, la forme que prend cette moralité artificielle relève de deux approches différentes : soit une forme maximalement éthique, qui dépend de l’implémentation stricte des théories morales préexistantes comme la déontologie Kantienne ou l’Utilitarisme, soit une forme minimaliste, qui applique des techniques de l’IA stochastique à l’analyse et agrégation de données portant sur les préférences morales d’une population, afin d’en tirer des principes généraux mobilisés ensuite dans la prise de décision des machines. Prises individuellement, aucune des deux approches n’arrivent à pondérer l’importance des contraintes morales avec la pertinence de l’acceptabilité publique des agents moraux artificiels. Nous proposons une approche alternative à la moralité artificielle, la théorie des valences éthiques, qui s’efforce d’accommoder ce genre de pondération, et nous l’appliquons au cas du véhicule autonome The ethics of emerging forms of artificial intelligence has become a prolific subject in both academic and public spheres. A great deal of these concerns flow from the need to ensure that these technologies do not cause harm—physical, emotional or otherwise—to the human agents with which they will interact. In the literature, this challenge has been met with the creation of artificial moral agents: embodied or virtual forms of artificial intelligence whose decision procedures are constrained by explicit normative principles, requiring the implementation of what is commonly called artificial morality into these agents. To date, the types of reasoning structures and principles which inform artificial morality have been of two kinds: first, an ethically maximal vision of artificial morality which relies on the strict implementation of traditional moral theories such as Kantian deontology or Utilitarianism, and second, a more minimalist vision which applies stochastic AI techniques to large data sets of human moral preferences so as to illicit or intuit general principles and preferences for the design of artificial morality. Taken individually, each approach is unable to fully answer the challenge of producing inoffensive behavior in artificial moral agents, most especially since both forms are unable to strike a balance between the ideal set of constraints which morality imposes on one hand, and the types of constraints public acceptability imposes, on the other. We provide an alternative approach to the design of artificial morality, the Ethical Valence Theory, whose purpose is to accommodate this balance, and apply this approach to the case of autonomous vehicles

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Morge, Maxime. "Syst'eme dialectique multi-agents pour l'aide 'a la concertation." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2005. http://tel.archives-ouvertes.fr/tel-00797376.

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Ce travail de recherche est consacré à la formalisation d'un processus de prise de décision collective et justifiée à l'aide d'un système multi-agents. Ce système est constitué d'agents cognitifs, autonomes et sociaux en interaction. S'appuyant sur la communication par envoi de messages, on parle de modèle d'interaction directe entre agents. Dans ce manuscrit, nous défendons la thèse selon laquelle le dialogue peut être considéré comme un processus argumentatif au travers duquel les participants jouent et arbitrent pour aboutir à une décision collective. Nous proposons ici un modèle de dialogue entre agents. Ce modèle, intitulé DIAL (DIALogue Is an Argumentative Labour ), sert de base à un système d'aide à la concertation.

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Bunnell, Lawrence. "FinPathlight: Framework for an Ontology-Based, Multiagent, Hybrid Recommender System Designed to Increase Consumer Financial Capability." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/5801.

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This study is a design science research (DSR) project in which a description of the development and evaluation process for several novel technological artifacts will be communicated. Specifically, this study will establish: 1) an ontology of recommender systems issues, 2) an ontology of financial capability goals, and 3) a framework for a Personal Financial Recommender System (PFRS) application designed to improve user financial capability, called FinPathlight. The impetus for the RecSys Issues Ontology is to address a gap in the literature by providing researchers with a comprehensive knowledge classification of the issues and limitations inherent to recommender systems research. The development of a Financial Capability Goals Ontology will contribute domain knowledge classification for technological systems within the domain of finance and serves as a recommendation item knowledgebase for our PFRS. The FinPathlight framework provides the architecture and principles of implementation for a novel, financial-technology (FinTech) PFRS. FinPathlight is designed to improve the financial capability of its users through the recommendation, tracking and assistance with achieving financial capability enhancing goals. This research is notable in that it expands the influence and furthers the relevance of information systems research by providing an explicitly applicable research solution to an area of significant socio-economic importance, financial capability, a heretofore unsolved “wicked problem” (Churchman 1967) domain. In light of current financial conditions, recommender systems research that addresses a problem such as consumer financial capability is a step towards ensuring that information systems research continues to matter and retain its influence and relevance in everyday practice.

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LIMA, Allan Diego Silva. "FAct: Um framework para a construção de sistemas multiatores." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/1804.

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Made available in DSpace on 2014-06-12T15:52:31Z (GMT). No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 Atores Sintéticos são agentes inteligentes que possuem personalidade, atuam em ambientes multimídias ou virtuais e são representados graficamente por avatares. Estas entidades são utilizadas em sistemas de simuladores como forma de enriquecer a interação entre a aplicação e seus usuários, proporcionando assim aumento da credibilidade do projeto. Com a sua popularização sugiram vários projetos que os utilizam. Estes projetos têm diversos aspectos em comum. Por exemplo, neles seus atores se comunicam e possuem modelos de personalidade. Contudo, apesar das similaridades os projetos encontrados na literatura foram implementados de forma independente. Ou seja, tiveram seu código fonte desenvolvido do zero. Porém, no âmbito dos sistemas multiagentes tal problema não ocorre devido à existência de diversos frameworks multiagentes que agrupam as funcionalidades comuns a tais sistemas, fazendo com que o desenvolvedor implemente apenas o que é relativo ao seu contexto de simulação. Porém, estes frameworks não são utilizados em sistemas multiarores, pois não suportam as peculiaridades dos sistemas multiatores. Buscando solucionar esse problema, este trabalho apresenta o FAct (Framework for Actors), um projeto criado especificamente para auxiliar na construção sistemas multiatores. Ele focado nas características peculiares destes sistemas e tem como principal objetivo reduzir o custo e tempo de desenvolvimento para os projetos baseados nesta tecnologia. Como forma de exemplificar o uso do FAct e avaliar o seu impacto no desenvolvimento de simuladores multiatores, serão apresentados dois simuladores implementados com base no framework

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Magg, Sven. "Self-organised task differentiation in homogeneous and heterogeneous groups of autonomous agents." Thesis, University of Hertfordshire, 2012. http://hdl.handle.net/2299/9038.

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The field of swarm robotics has been growing fast over the last few years. Using a swarm of simple and cheap robots has advantages in various tasks. Apart from performance gains on tasks that allow for parallel execution, simple robots can also be smaller, enabling them to reach areas that can not be accessed by a larger, more complex robot. Their ability to cooperate means they can execute complex tasks while offering self-organised adaptation to changing environments and robustness due to redundancy. In order to keep individual robots simple, a control algorithm has to keep expensive communication to a minimum and has to be able to act on little information to keep the amount of sensors down. The number of sensors and actuators can be reduced even more when necessary capabilities are spread out over different agents that then combine them by cooperating. Self-organised differentiation within these heterogeneous groups has to take the individual abilities of agents into account to improve group performance. In this thesis it is shown that a homogeneous group of versatile agents can not be easily replaced by a heterogeneous group, by separating the abilities of the versatile agents into several specialists. It is shown that no composition of those specialists produces the same outcome as a homogeneous group on a clustering task. In the second part of this work, an adaptation mechanism for a group of foragers introduced by Labella et al. (2004) is analysed in more detail. It does not require communication and needs only the information on individual success or failure. The algorithm leads to self-organised regulation of group activity depending on object availability in the environment by adjusting resting times in a base. A possible variation of this algorithm is introduced which replaces the probabilistic mechanism with which agents determine to leave the base. It is demonstrated that a direct calculation of the resting times does not lead to differences in terms of differentiation and speed of adaptation. After investigating effects of different parameters on the system, it is shown that there is no efficiency increase in static environments with constant object density when using a homogeneous group of agents. Efficiency gains can nevertheless be achieved in dynamic environments. The algorithm was also reported to lead to higher activity of agents which have higher performance. It is shown that this leads to efficiency gains in heterogeneous groups in static and dynamic environments.

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Gâteau, Benjamin. "Modélisation et Supervision d'Institutions Multi-Agents." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2007. http://tel.archives-ouvertes.fr/tel-00777825.

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Le domaine scientifique dans lequel nos recherches s'insèrent est celui des Systèmes Multi-Agents. Dans ce domaine, nous nous intéressons à l'élaboration de modèles globaux définissant et structurant l'activité commune d'agents autonomes. En effet l'autonomie d'un agent se traduit par sa capacité à déterminer ses propres buts face à la configuration de l'environnement ainsi qu'à ses motivations. Du fait de cette autonomie, des conflits liés à l'existence de buts propres à chacun des agents autonomes d'une société d'agents peuvent être incompatibles, complémentaires ou en compétition avec les objectifs de la société. Des modèles de gestion de conflits existent, et dans le cadre de ce travail, nous nous sommes intéressés aux modèles organisationnels. Nous défendons la thèse selon laquelle la définition et la mise en place de contraintes globales influençant le fonctionnement d'agents autonomes doit être faite de manière à prendre en compte l'éventualité que les agents puissent ne pas respecter les contraintes selon les contextes et les objectifs individuels de chacun. Afin d'atteindre ces objectifs, nous proposons un modèle d'Institution Electronique comportant une description explicite et déclarative des contraintes à appliquer aux agents ainsi qu'un système de supervision et de renforcement de ces contraintes. Ce modèle permet de définir et de structurer grâce à MoiseInst l'activité d'un ensemble d'agents autonomes au sein d'une organisation normée et de superviser son respect grâce au système d'arbitrage Synai. Ce dernier est composé d'un ensemble d'agents de supervision capables de mettre en place des mécanismes de régulation et de renforcement de ces contraintes sur les agents autonomes. L'application du modèle se fait dans deux domaines totalement différents puisqu'ils concernent la création et l'exécution de contenu pour la télévision interactive d'un côté et la gestion de contrats électroniques d'une plate-forme de e-commerce de l'autre. Ils exhibent cependant la même problématique d'arbitrage d'entités autonomes devant respecter des contraintes. De plus, ces deux applications sont complémentaires par leur différence de portée de l'Institution.

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31

Giansiracusa, Michelangelo Antonio. "A secure infrastructural strategy for safe autonomous mobile agents." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16052/1/Michaelangelo_Giansiracusa_Thesis.pdf.

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Portable languages and distributed paradigms have driven a wave of new applications and processing models. One of the most promising, certainly from its early marketing, but disappointing (from its limited uptake)is the mobile agent execution and data processing model. Mobile agents are autonomous programs which can move around a heterogeneous network such as the Internet, crossing through a number of different security domains, and perform some work at each visited destination as partial completion of a mission for their agent user. Despite their promise as a technology and paradigm to drive global electronic services (i.e.any Internet-driven-and-delivered service, not solely e-commerce related activities), their up take on the Internet has been very limited. Chief among the reasons for the paradigm's practical under-achievement is there is no ubiquitous frame work for using Internet mobile agents, and non-trivial security concerns abound for the two major stake holders (mobile agent users and mobile agent platform owners). While both stake holders have security concerns with the dangers of the mobile agent processing model, most investigators in the field are of the opinion that protecting mobile agents from malicious agent platforms is more problematic than protecting agent platforms from malicious mobile agents. Traditional cryptographic mechanisms are not well-suited to counter the bulk of the threats associated with the mobile agent paradigm due to the untrusted hosting of an agent and its intended autonomous, flexible movement and processing. In our investigation, we identified that the large majority of the research undertaken on mobile agent security to date has taken a micro-level perspective. By this we mean research focused solely on either of the two major stakeholders, and even then often only on improving measures to address one security issue dear to the stake holder - for example mobile agent privacy (for agent users) or access control to platform resources (for mobile agent platform owners). We decided to take a more encompassing, higher-level approach in tackling mobile agent security issues. In this endeavour, we developed the beginnings of an infrastructural-approach to not only reduce the security concerns of both major stakeholders, but bring them transparently to a working relationship. Strategic utilisation of both existing distributed system trusted-third parties (TTPs) and novel mobile agent paradigm-specific TTPs are fundamental in the infrastructural framework we have devised. Besides designing an application and language independent frame work for supporting a large-scale Internet mobile agent network, our Mobile Agent Secure Hub Infrastructure (MASHIn) proposal encompasses support for flexible access control to agent platform resources. A reliable means to track the location and processing times of autonomous Internet mobile agents is discussed, withfault-tolerant handling support to work around unexpected processing delays. Secure,highly-effective (incomparison to existing mechanisms) strategies for providing mobile agent privacy, execution integrity, and stake holder confidence scores were devised - all which fit comfortably within the MASHIn framework. We have deliberately considered the interests - withoutbias -of both stake holders when designing our solutions. In relation to mobile agent execution integrity, we devised a new criteria for assessing the robustness of existing execution integrity schemes. Whilst none of the existing schemes analysed met a large number of our desired properties for a robust scheme, we identified that the objectives of Hohl's reference states scheme were most admirable - particularly real - time in - mission execution integrity checking. Subsequently, we revised Hohl's reference states protocols to fit in the MASHIn framework, and were able to overcome not only the two major limitations identified in his scheme, but also meet all of our desired properties for a robust execution integrity scheme (given an acceptable decrease in processing effiency). The MASHIn offers a promising new perspective for future mobile agent security research and indeed a new frame work for enabling safe and autonomous Internet mobile agents. Just as an economy cannot thrive without diligent care given to micro and macro-level issues, we do not see the security prospects of mobile agents (and ultimately the prospects of the mobile agent paradigm) advancing without diligent research on both levels.

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32

Giansiracusa, Michelangelo Antonio. "A Secure Infrastructural Strategy for Safe Autonomous Mobile Agents." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16052/.

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Portable languages and distributed paradigms have driven a wave of new applications and processing models. One of the most promising, certainly from its early marketing, but disappointing (from its limited uptake)is the mobile agent execution and data processing model. Mobile agents are autonomous programs which can move around a heterogeneous network such as the Internet, crossing through a number of different security domains, and perform some work at each visited destination as partial completion of a mission for their agent user. Despite their promise as a technology and paradigm to drive global electronic services (i.e.any Internet-driven-and-delivered service, not solely e-commerce related activities), their up take on the Internet has been very limited. Chief among the reasons for the paradigm's practical under-achievement is there is no ubiquitous frame work for using Internet mobile agents, and non-trivial security concerns abound for the two major stake holders (mobile agent users and mobile agent platform owners). While both stake holders have security concerns with the dangers of the mobile agent processing model, most investigators in the field are of the opinion that protecting mobile agents from malicious agent platforms is more problematic than protecting agent platforms from malicious mobile agents. Traditional cryptographic mechanisms are not well-suited to counter the bulk of the threats associated with the mobile agent paradigm due to the untrusted hosting of an agent and its intended autonomous, flexible movement and processing. In our investigation, we identified that the large majority of the research undertaken on mobile agent security to date has taken a micro-level perspective. By this we mean research focused solely on either of the two major stakeholders, and even then often only on improving measures to address one security issue dear to the stake holder - for example mobile agent privacy (for agent users) or access control to platform resources (for mobile agent platform owners). We decided to take a more encompassing, higher-level approach in tackling mobile agent security issues. In this endeavour, we developed the beginnings of an infrastructural-approach to not only reduce the security concerns of both major stakeholders, but bring them transparently to a working relationship. Strategic utilisation of both existing distributed system trusted-third parties (TTPs) and novel mobile agent paradigm-specific TTPs are fundamental in the infrastructural framework we have devised. Besides designing an application and language independent frame work for supporting a large-scale Internet mobile agent network, our Mobile Agent Secure Hub Infrastructure (MASHIn) proposal encompasses support for flexible access control to agent platform resources. A reliable means to track the location and processing times of autonomous Internet mobile agents is discussed, withfault-tolerant handling support to work around unexpected processing delays. Secure,highly-effective (incomparison to existing mechanisms) strategies for providing mobile agent privacy, execution integrity, and stake holder confidence scores were devised - all which fit comfortably within the MASHIn framework. We have deliberately considered the interests - withoutbias -of both stake holders when designing our solutions. In relation to mobile agent execution integrity, we devised a new criteria for assessing the robustness of existing execution integrity schemes. Whilst none of the existing schemes analysed met a large number of our desired properties for a robust scheme, we identified that the objectives of Hohl's reference states scheme were most admirable - particularly real - time in - mission execution integrity checking. Subsequently, we revised Hohl's reference states protocols to fit in the MASHIn framework, and were able to overcome not only the two major limitations identified in his scheme, but also meet all of our desired properties for a robust execution integrity scheme (given an acceptable decrease in processing effiency). The MASHIn offers a promising new perspective for future mobile agent security research and indeed a new frame work for enabling safe and autonomous Internet mobile agents. Just as an economy cannot thrive without diligent care given to micro and macro-level issues, we do not see the security prospects of mobile agents (and ultimately the prospects of the mobile agent paradigm) advancing without diligent research on both levels.

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33

Cointe, Nicolas. "Jugement éthique pour la décision et la coopération dans les systèmes multi-agents." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEM043/document.

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L’usage croissant des systèmes multi-agents dans divers domaines d’application soulève la nécessité de concevoir des agents capables de prendre des décisions s’appuyant sur des principes éthiques. Notre objectif est d’équiper les agents de capacités de raisonnement éthique pour permettre la mise en place de coopérations fondées sur l’éthique. Ce travail propose un modèle de jugement éthique pour les agents autonomes artificiels dans les systèmes multi-agents permettantde guider leurs décisions afin d’influencer leur comportement individuel d’une part, et de décrire un cadre de coopération fondée sur l’éthique d’autre part. Les éléments de ce modèle reposent sur une distinction entre la morale (ou théorie du bien), décrivant le caractère bon ou mauvais des actions d’un agent en faisant appel à la définition de valeurs morales et de règles morales, et l’éthique (ou théorie du juste), permettant de juger de l’action qu’il est juste d’effectuer dans une situation au regard d’un ensemble ordonné de principes éthiques et des actions moralement évaluées. L’agent, en employant ce modèle de jugement comme un processus décisionnel, adopte alors un comportement éthique du point de vue des théories du bien et du juste qui lui sont confiées. Il lui est également possible d’employer ce modèle pour juger le comportement des autres agents et tenir compte de ce jugement dans son propre comportement vis-à-vis des agents jugés.La présentation de ce modèle est accompagnée d’expérimentations illustrant son utilisation dans un domaine applicatif rséaliste de gestion éthique d’actifs financiers permettant d’éprouver l’influence du jugement sur le comportement des agents The increasing use of multiagent systems in various fields raises the need of autonomous agents able to take into account such ethical principles in their decisions. More and more propositions are published, but they are often agent-centered and they don’t consider the issues raised by the interactions between artificial agents and possibly humans, potentially using another ethics. Our goal is to give the agents the ability to reason on ethics to enable an ethics-based cooperation in multiagent systems. This work presents a model of ethical judgment for artificial autonomous agents in multiagent systems both useful to influence their decisions and behaviors, and describes an ethics-based cooperation framework. This model distinguishes the morality (or theory of the good), describing the goodness of actions in a context regarding a set of moral values and moral rules, and ethics (or theory of the right), describing the rightness of an action regarding a set of ethical principles. The use of this model in the decision process generates a conform behavior regarding the chosen theories of good and right. An agent may also use this model to judge the observed behavior of the other agents and employ this judgment to adapt its own behavior towards the judged agents. The detailed presentation of this model is followed by some experimentations to show the use of this model in a realistic application based on an ethical asset management scenario. The results show how the behaviors of the agents might be impacted and the efficiency of this model to discriminate the behaviors of the others

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34

Poli, Nicola. "Game Engines and MAS: BDI & Artifacts in Unity." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15657/.

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In questa tesi vedremo un breve sunto riguardo lo stato dei Sistemi Multi-Agente e andremo ad analizzare le limitazioni che attualmente ne impediscono l'utilizzo ai programmatori di videogiochi. Dopodiché, andremo a proporre un nuovo linguaggio BDI, basato su Prolog e inspirato a Jason, che, grazie all'interprete Prolog sviluppato da I. Horswill, darà la possibilità al programmatore di videogiochi di esprimere comportamenti dichiarativi di alto livello per agenti autonomi all'interno del game engine Unity. Andremo anche a proporre una versione di Artefatto per la modellazione dell'ambiente in una scena Unity e un layer di comunicazione che agenti e artefatti possano utilizzare per interagire tra loro. Infine presenteremo un caso di studio per sottolineare i benefici che questo sistema fornisce.

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35

Wang, Zhu Wei. "Multi-agent path finding in an order picking system." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3950627.

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36

Szwaykowska, Klementyna. "Controlled Lagrangian particle tracking: analyzing the predictability of trajectories of autonomous agents in ocean flows." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50357.

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Use of model-based path planning and navigation is a common strategy in mobile robotics. However, navigation performance may degrade in complex, time-varying environments under model uncertainty because of loss of prediction ability for the robot state over time. Exploration and monitoring of ocean regions using autonomous marine robots is a prime example of an application where use of environmental models can have great benefits in navigation capability. Yet, in spite of recent improvements in ocean modeling, errors in model-based flow forecasts can still significantly affect the accuracy of predictions of robot positions over time, leading to impaired path-following performance. In developing new autonomous navigation strategies, it is important to have a quantitative understanding of error in predicted robot position under different flow conditions and control strategies. The main contributions of this thesis include development of an analytical model for the growth of error in predicted robot position over time and theoretical derivation of bounds on the error growth, where error can be attributed to drift caused by unmodeled components of ocean flow. Unlike most previous works, this work explicitly includes spatial structure of unmodeled flow components in the proposed error growth model. It is shown that, for a robot operating under flow-canceling control in a static flow field with stochastic errors in flow values returned at ocean model gridpoints, the error growth is initially rapid, but slows when it reaches a value of approximately twice the ocean model gridsize. Theoretical values for mean and variance of error over time under a station-keeping feedback control strategy and time-varying flow fields are computed. Growth of error in predicted vehicle position is modeled for ocean models whose flow forecasts include errors with large spatial scales. Results are verified using data from several extended field deployments of Slocum autonomous underwater gliders, in Monterey Bay, CA in 2006, and in Long Bay, SC in 2012 and 2013.

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37

Lucien, Laurent. "Contribution à une modélisation globale de la collaboration dans les systèmes multi-agents : Application aux entités mobiles intelligentes." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCD039/document.

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Nous vivons aujourd'hui dans un monde de plus en plus complexe et interconnecté où de nombreuses entités, de plus en plus intelligentes, génèrent une multitude d'interactions qui peuvent contribuer à enrichir leurs capacités. Nous nous intéressons à la collaboration qui favorisera la réalisation de tâches complexes par ces machines d'aujourd'hui et de demain en stimulant ces interactions structurées et en intégrant des processus de décisions intelligents. Par ce biais, cela contribuera à améliorer leur fonctionnement et pourra participer à leur perfectionnement (meilleures connaissances de leur environnement, rapidité d'action et de décision, apport de nouvelles compétences). L'objectif principal de la thèse est donc de contribuer à la compréhension de ce qu'est la collaboration, de sa définition à sa mise en œuvre, en mettant en lumière ses concepts sous-jacents. Nous proposons une méthode d'analyse du besoin et des contraintes ainsi qu'un modèle d'architecture d'agent collaboratif (HACCA) permettant d'intégrer toutes les caractéristiques des processus collaboratifs que nous présentons. Nous présentons également une première implémentation dans la plateforme multi-agents GAMA.Dans le cadre de cette étude, nous nous intéressons à deux cas d'application d'entités mobiles : les drones et les véhicules connectés. Ainsi nous contribuons également plus largement aux besoins d'autonomie et de décision des drones, des véhicules connectés et autonomes du futur, dans un contexte temporel contraint où la qualité des interactions est primordiale pour optimiser le processus de réalisation des objectifs We live today in an increasingly complex and interconnected world where many entities, increasingly intelligent, generate a multitude of interactions that can contribute to enrich their capabilities.We are interested in collaboration that will enable complex tasks to be performed by these machines of today and tomorrow by stimulating these structured interactions and integrating intelligent decision-making processes. In this way, it will contribute to improve their functioning and will be able to participate in their improvement (better knowledge of their environment, speed of action and decision-making, provision of new skills).The main objective of the thesis is therefore to contribute to the understanding of what collaboration is, from its definition to its implementation, by highlighting its underlying concepts. We propose a method of analysis (needs and constraints) and a collaborative agent architecture model (HACCA) to integrate all the characteristics of the collaborative processes that we present. We are also showing a first implementation in the GAMA multi-agent platform.As part of this study, we are interested in two cases of application of mobile entities: drones and connected vehicles.Thus we also contribute more to the autonomy needs and decision-making process of drones, connected and autonomous vehicles of the future, in a constrained temporal context where the quality of interactions is essential to optimize the process of achieving objectives

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Estgren, Martin. "Lightweight User Agents." Thesis, Linköpings universitet, Artificiell intelligens och integrerad datorsystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-129909.

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The unit for information security and IT architecture at The Swedish Defence Research Agency (FOI) conducts work with a cyber range called CRATE (Cyber Range and Training Environment). Currently, simulation of user activity involves scripts inside the simulated network. This solution is not ideal because of the traces it leaves in the system and the general lack of standardised GUI API between different operating systems. FOI are interested in testing the use of artificial user agent located outside the virtual environment using computer vision and the virtualisation API to execute actions and extract information from the system. This paper focuses on analysing the reliability of template matching, a computer vision algorithm used to localise objects in images using already identified images of said object as templates. The analysis will evaluate both the reliability of localising objects and the algorithms ability to correctly identify if an object is present in the virtual environment. Analysis of template matching is performed by first creating a prototype of the agent's sensory system and then simulate scenarios which the agent might encounter. By simulating the environment, testing parameters can be manipulated and monitored in a reliable way. The parameters manipulated involves both the amount and type of image noise in the template and screenshot, the agent’s discrimination threshold for what constitutes a positive match, and information about the template such as template generality. This paper presents the performance and reliability of the agent in regards to what type of image noise affects the result, the amount of correctly identified objects given different discrimination thresholds, and computational time of template matching when different image filters are applied. Furthermore the best cases for each study are presented as comparison for the other results. In the end of the thesis we present how for screenshots with objects very similar to the templates used by the agent, template matching can result in a high degree of accuracy in both object localization and object identification and that a small reduction of similarity between template and screenshot to reduce the agent's ability to reliably identifying specific objects in the environment.

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Ouzrout, Yacine. "Modélisation et Simulation d'Organisations Productives Réactives: Une Approche Moiti-Agents." Phd thesis, INSA de Lyon, 1990. http://tel.archives-ouvertes.fr/tel-00838911.

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L'objectif de cette thèse est de proposer une démarche méthodologique de conception d'un modèle de simulation de systèmes de production qui intègre une représentation des comportements distribués et cognitifs des acteurs décisionnels, et dont l'intérêt est de permettre d'étudier la pertinence de changements organisationnels dans ces systèmes. En effet, l'analyse des conditions d'évolution des systèmes de production et de leur contexte a permis de mettre en relief le besoin de " réactivité " pour faire face à un environnement de moins en moins stable et prévisible et devant lequel l'organisation doit chercher des alternatives à un fonctionnèment planifié, prédictif, figé et séquentiel. Les réponses organisationnelles des entreprises à ces sollicitations s'expriment par un mouvement vers la fleXIbilité et l'intégration, et passent par un rapprochement entre la structure décisionnelle et la structure physique. Pour mettre en évidence cette nouvelle réalité, nous proposons un processus de modélisation qui débute par la construction d'un modèle conceptuel de compréhension des organisations, basé sur une représentation des processus de décision, et sur une formalisation des phénomènes d'orientation des comportements décisionnels. En parallèle, nous analysons les concepts associés à la problématique des systèmes multi-agents, systèmes qui étudient l'émergence de comportements collectifs résultant de l'activité coopérative de plusieurs entités autonomes "intelligentes" sur lesquelles l'expertise est répartie. Ces études convergent vers un modèle de simulation issu des techniques de simulation à événements discrets, dans lequel nous intégrons une modélisation du système décisionnel à base d'agents. Enfin, l'implémentation de ce modèle sera basée sur des techniques de simulation orientée objets (objets actifs, programmation concurrente), et sera validée sur deux exemples, l'un pédagogique et conceptuel, 1 'autre industriel.

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40

Bakolas, Efstathios. "Optimal steering for kinematic vehicles with applications to spatially distributed agents." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42873.

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The recent technological advances in the field of autonomous vehicles have resulted in a growing impetus for researchers to improve the current framework of mission planning and execution within both the military and civilian contexts. Many recent efforts towards this direction emphasize the importance of replacing the so-called monolithic paradigm, where a mission is planned, monitored, and controlled by a unique global decision maker, with a network centric paradigm, where the same mission related tasks are performed by networks of interacting decision makers (autonomous vehicles). The interest in applications involving teams of autonomous vehicles is expected to significantly grow in the near future as new paradigms for their use are constantly being proposed for a diverse spectrum of real world applications. One promising approach to extend available techniques for addressing problems involving a single autonomous vehicle to those involving teams of autonomous vehicles is to use the concept of Voronoi diagram as a means for reducing the complexity of the multi-vehicle problem. In particular, the Voronoi diagram provides a spatial partition of the environment the team of vehicles operate in, where each element of this partition is associated with a unique vehicle from the team. The partition induces, in turn, a graph abstraction of the operating space that is in a one-to-one correspondence with the network abstraction of the team of autonomous vehicles; a fact that can provide both conceptual and analytical advantages during mission planning and execution. In this dissertation, we propose the use of a new class of Voronoi-like partitioning schemes with respect to state-dependent proximity (pseudo-) metrics rather than the Euclidean distance or other generalized distance functions, which are typically used in the literature. An important nuance here is that, in contrast to the Euclidean distance, state-dependent metrics can succinctly capture system theoretic features of each vehicle from the team (e.g., vehicle kinematics), as well as the environment-vehicle interactions, which are induced, for example, by local winds/currents. We subsequently illustrate how the proposed concept of state-dependent Voronoi-like partition can induce local control schemes for problems involving networks of spatially distributed autonomous vehicles by examining different application scenarios.

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Coutinho, Luciano Reis. "Interoperabilidade organizacional em sistemas multiagentes abertos baseada em engenharia dirigida por modelos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/3/3141/tde-29092010-152356/.

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Nesta tese, propõe-se integrar, de modo sistemático, modelos organizacionais para prover interoperabilidade organizacional em sistemas multiagentes abertos. A interoperabilidade organizacional consiste em permitir que, em uma mesma organização de agentes, coexistam agentes desenvolvidos a partir de modelos organizacionais distintos. Para realizar tal intuito, aplica-se uma abordagem baseada em técnicas da Engenharia Dirigida por Modelos. A abordagem proposta divide-se em três etapas principais: (1) representar a estrutura conceitual de modelos organizacionais através de metamodelos; (2) identificar correspondências entre as estruturas conceituais dos modelos organizacionais utilizando como heurística a idéia de dimensões e padrões de modelagem organizacional ; e (3) combinar os metamodelos dos modelos organizacionais seguindo um algoritmo de junção de modelos baseado em grafos e articulações de grafos. Utilizando a abordagem proposta, quatro modelos organizacionais existentes são integrados: os modelos AGR, STEAM, MOISE+ e ISLANDER. Para ilustrar o uso da integração de metamodelos no problema de interoperabilidade organizacional, especifica-se e implementa-se uma infraestrutura de interoperabilidade organizacional chamada MAORI (Model-driven Architecture for Organizational Interoperability). A infraestrutura MAORI é estruturada em duas camadas: (1) a camada M2M, na qual a integraçãoo de modelos realizada é utilizada para traduzir especificações e estados organizacionais, e (2) a camada ORI, na qual infraestruturas organizacionais são interconectadas. Para testar e validar toda a proposta, a infraestrutura MAORI foi implementada para as infraestruturas organizacionais S-MOISE+ e MADKIT, e uma aplicaçào denominada WritePaper foi desenvolvida. A partir das implementações, alguns experimentos foram realizados. Os resultados obtidos demonstram que a integração de modelos organizacionais proposta, realizada na infraestrutura de interoperabilidade MAORI, efetivamente interconecta infraestruturas organizacionais distintas e permite que, em uma mesma organização de agentes, coexistam agentes desenvolvidos a partir de modelos organizacionais distintos. This thesis proposes to integrate systematically organizational models for providing organizational interoperability in open multiagent systems. Organizational interoperability consists in enabling the participation, in the same agent organization, of agents developed with different organizational models. For this purpose, it is applied an approach based on techniques from Model-driven Engineering. The approach is divided in three main steps: (1) to represent the conceptual structure of organizational models by means of metamodels; (2) to identify correspondences among the conceptual structures of the organizational models using as heuristics the idea of organizational modeling dimensions and patterns; (3) to combine the metamodels of the organizational models by following a merge algorithm based on graphs and graph articulations. Using the proposed approach, four existing organizational models are integrated: AGR, STEAM, MOISE+ and ISLANDER. To illustrate the use of the integration, an organizational interoperability infrastructure called MAORI (Model-driven Architecture for Organizational Interoperability) is specified and implemented. The MAORI infrastructure is structured in two layers: (1) the M2M layer, in which the integration of models is used to translate the organizational specifications and states, and (2) the ORI layer, in which the organizational infrastructures are interconnected. To test and validate the approach, MAORI infrastructure was implemented for the organizational infrastructures S-MOISE+ and MADKIT, and an application called Write Paper was developed. Using the implementations, some experiments were done. The results show that the organizational model integration, implemented in the MAORI infrastructure, effectively interconnects distinct organizational infrastructures and enables the participation, in the same agent organization, of agents developed with different organizational models.

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Kieling, Gustavo Luiz. "Inserção de conhecimento probabilístico para construção de agentes BDI modelados em redes bayesianas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/28741.

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A representação do conhecimento de maneira mais fiel possível à realidade é uma meta histórica e não resolvida até o momento na área da Inteligência Artificial. Problemas são resolvidos e decisões são tomadas levando-se em conta diversos tipos de conhecimentos, os quais muitos são tendenciosos, inexatos, ambíguos ou ainda incompletos. A fim de tentar emular a capacidade de representação do conhecimento humano, levando-se em conta as diversas dificuldades inerentes, tem-se construído sistemas computacionais que armazenam o conhecimento das mais diversas formas. Dentro deste contexto, este trabalho propõe um experimento que utiliza duas formas distintas de representação do conhecimento: a simbólica, neste caso BDI, e a probabilística, neste caso Redes Bayesianas. Para desenvolvermos uma prova de conceito desta proposta de representação do conhecimento estamos utilizando exemplos que serão construídos através da tecnologia de programação voltada para agentes. Para tal, foi desenvolvida uma implementação de um Sistema MultiAgente, estendendo o framework Jason através da implementação de um plugin chamado COPA. Para a representação do conhecimento probabilístico, utilizamos uma ferramenta de construção de Redes Bayesianas, também adaptada a este sistema. Os estudos de caso mostraram melhorias no gerenciamento do conhecimento incerto em relação às abordagens de construções de agentes BDI clássicos, ou seja, que não utilizam conhecimento probabilístico. Achieving faithful representation of knowledge is a historic and still unreached goal in the area of Artificial Intelligence. Problems are solved and decisions are made taking into consideration different kinds of knowledge, from which many are biased, inaccurate, ambiguous or still incomplete. Computational systems that store knowledge in many different ways have been built in order to emulate the capacity of human knowledge representation, taking into consideration the several inherent difficulties to it. Within this context, this paper proposes an experiment that utilizes two distinct ways of representing knowledge: symbolic, BDI in this case, and probabilistic, Bayesian Networks in this case. In order to develop a proof of concept of this propose of knowledge representation, examples that will be built through agent oriented programming technology will be used. For that, implementation of a MultiAgent System was developed, extending the Jason framework through the implementation of a plugin called COPA. For the representation of probabilistic knowledge, a Bayesian Network building tool, also adapted to this system, was used. The case studies showed improvement in the management of uncertain knowledge in relation to the building approaches of classic BDI agents, i.e., that do not use probabilistic knowledge.

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Assaad, Mohamad Ali. "An overview on systems of systems control : general discussions and application to multiple autonomous vehicles." Thesis, Compiègne, 2019. http://www.theses.fr/2019COMP2466/document.

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La thèse porte sur le contrôle des systèmes de systèmes (SdS) et, sur la manière de construire des SdS adaptables et fiables. Ce travail fait partie du laboratoire d’excellence Labex MS2T sur le développement des SdS technologiques. Les SdS sont des systèmes complexes constitués de plusieurs systèmes indépendants qui fonctionnent ensemble pour atteindre un objectif commun. L’ingénierie des SdS est une approche qui se concentre sur la manière de construire et de concevoir des SdS fiables capables de s’adapter à l’environnement dynamique dans lequel ils évoluent. Compte tenu de l’importance du contrôle des systèmes constituants (SC) pour atteindre les objectifs du SdS , la première partie de cette thèse a consisté en une étude bibliographique sur le sujet du contrôle des SdS. Certaines méthodes de contrôle existent pour les systèmes à grande échelle et les systèmes multi-agents, à savoir, le contrôle hiérarchique, distribué et décentralisé peuvent être utiles et sont utilisés pour contrôler les SdS. Ces méthodes ne conviennent pas pour contrôler un SdS dans sa globalité et son évolution, en raison de l’indépendance de leur SC ; alors que les “frameworks” multi-vues conviennent mieux à cet objectif. Une approche de ”framework” générale est proposée pour modéliser et gérer les interactions entre les SC dans un SdS. La deuxième partie de notre travail a consisté à contribuer aux systèmes de transport intelligent. À cette fin, nous avons proposé le gestionnaire de manœuvres coopératives pour les véhicules autonomes (CMMAV), un “framework” qui guide le développement des applications coopératives dans les véhicules autonomes. Pour valider le CMMAV, nous avons développé le gestionnaire de manœuvres latérales coopératives (CLMM), une application sur les véhicules autonomes qui permet d’échanger des demandes afin de coopérer lors de manœuvres de dépassement sur autoroute. Cette application a été validée par des scénarios formels, des simulations informatiques, et testée sur les véhicules autonomes du projet Robotex au laboratoire Heudiasyc This thesis focuses on System of Systems (SoS) control, and how to build adaptable and reliable SoS. This work is part of the Labex MS2T laboratory of excellence on technological SoS development. SoS are complex systems that consist of multiple independent systems that work together to achieve a common goal. SoS Engineering is an approach that focuses on how to build and design reliable SoS that can adapt to the dynamic environment in which they operate. Given the importance of controlling constituent systems (CS) in order to achieve SoS objectives, the first part of this thesis involved a literature study about the subject of SoS control. Some control methods exist for large-scale systems and multi-agent systems, namely, hierarchical, distributed, and decentralized control might be useful and are used to control SoS. These methods are not suitable for controlling SoS in its whole, because of the independence of their CS; whereas, multi-views frameworks are more suitable for this objective. A general framework approach is proposed to model and manage the interactions between CS in a SoS. The second part of our work consisted of contributing to Intelligent Transportation Systems. For this purpose, we have proposed the Cooperative Maneuvers Manager for Autonomous Vehicles (CMMAV), a framework that guides the development of cooperative applications in autonomous vehicles. To validate the CMMAV, we have developed the Cooperative Lateral Maneuvers Manager (CLMM), an application on the autonomous vehicles that enables equipped vehicles to exchange requests in order to cooperate during overtaking maneuvers on highways. It was validated by formal scenarios, computer simulations, and tested on the autonomous vehicles of the Equipex Robotex in Heudiasyc laboratory

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Verdaguer, Planas Marta. "Avaluació del paradigma d'agents en la gestió d'un sistema complex d'aigües residuals." Doctoral thesis, Universitat de Girona, 2012. http://hdl.handle.net/10803/97128.

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The thesis presents and evaluates the application of the paradigm of agents to the management of the urban wastewater system. The system is conceptualised as a multi-agent system from the development of the models of agents and communication paths. In the development, it has become obvious that coordination (of volumes and pollutant loads) between all the wastewater treatment inputs and the available capacity of the treatment is a key point in the system’s performance. To consider this factor, a coordinating agent is defined. This agent executes the coordination of inputs and the prioritisation of industrial wastewaters when the treatment does not have sufficient available capacity. The prioritisation is solved by a meta-heuristic of ant colony optimisation, which has been instantiated by four algorithmic versions. Finally, the system has been implemented and consecutive cycles of simulation have been executed with the conclusion that the paradigm of agents is a feasible proposal. La tesi presenta i avalua l’aplicació del paradigma d’agents en la gestió d’un sistema d’aigües residuals urbanes. El sistema es conceptualitza com a sistema multiagent a partir del desenvolupament dels models d’agents i d’enllaços de comunicació. En el desenvolupament s’evidencia que la coordinació (de volums i càrregues contaminants) entre totes les aportacions d’aigües residuals al tractament i la capacitat disponible d’aquest, constitueix un punt clau del funcionament del sistema. Per tal de considerar-ho, es defineix un agent Coordinador que executa la coordinació de les aportacions al tractament i a més, la priorització dels efluents industrials quan el tractament no disposa de capacitat suficient per admetre totes les propostes d’aportacions. La priorització es resol emprant una metaheurística d’optimització de colònia de formigues, la qual s’instancia mitjançant quatre versions algorísmiques diferents. Per últim, s’implementa el sistema i s’executen cicles consecutius de simulació mostrant com el paradigma constitueix una proposta factible.

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Conforto, nedelmann Déborah. "Vers le passage à l'échelle de l'allocation en ligne multi-agents multi-tâches." Electronic Thesis or Diss., Toulouse, ISAE, 2024. http://www.theses.fr/2024ESAE0049.

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Cette thèse s'inscrit dans le contexte de l'allocation en ligne multi-agents multi-tâches, dont le but est de coordonner efficacement un ensemble d'agents (ressources) afin de distribuer des tâches entre eux. À titre d'exemple d'application, nous pouvons citer les cas où des clients font des requêtes à un fournisseur de services qui cherchera la meilleure répartition des tâches parmi son ensemble d'agents : des taxis répondant à la demande des clients ou des robots assurant la distribution de colis.Contrairement au cadre hors ligne, qui suppose une connaissance totale du problème d'allocation à résoudre avant le début de l’allocation, dans le cadre en ligne, les tâches arrivent au cours du temps et doivent être allouées de manière dynamique. Ce cadre d'optimisation en ligne présente plusieurs défis. Tout d'abord, l'allocation répétée des tâches aux agents est un problème NP-difficile, dont une solution doit être trouvée en un temps limité, parfois très court. Ensuite, la connaissance sur l'arrivée de futures tâches (par exemple, moment d'arrivée et localisation) est en général modeste, ce qui rend difficile le raisonnement sur le long terme (c’est-à-dire optimiser le positionnement des agents pour la planification à plus long terme). Enfin, la taille du problème à traiter en termes d'agents et de tâches peut être importante, particulièrement dans un cadre réaliste où la recherche d’une solution en temps limité peut être parfois compromise.Dans ce contexte, cette thèse propose différentes contributions. Tout d'abord, cette thèse propose une approche proactive qui permet d'anticiper la disponibilité des agents dans un futur proche afin d'obtenir une coordination efficace (c’est-à-dire minimisant la distance parcourue par les agents et le temps qu'ils restent désœuvrés). Cette approche proactive a été comparée à une approche réactive classique. Les résultats obtenus dans deux problèmes de référence, l'un synthétique et l'autre basé sur des données réelles, montrent que la méthode proactive permet d'obtenir de meilleurs résultats en termes de coûts et de nombre de tâches allouées aux agents par rapport à une approche réactive, tout en diminuant le temps d'inactivité des ressources. Malgré les résultats encourageants obtenus, la méthode proposée présente des limitations de scalabilité dans notre problème de référence basé sur des données réelles. Pour pallier cette limitation, cette thèse propose une deuxième approche qui développe une méta-heuristique d'allocation multi-agent multi-tâche, appelée SKATE - Successive Rank-based Task Assignment for Proactive Online Planning, permettant le passage à l'échelle. SKATE permet de traiter des problèmes avec des milliers d'agents et de tâches en obtenant des solutions efficaces en temps limité. SKATE présente de bons résultats en termes de coût des solutions trouvées pour un tel ordre de grandeur d'agents et de tâches, comparé à des méthodes classiques de la littérature, telles qu'un algorithme génétique ou la programmation linéaire en nombres entiers. Grâce à ces résultats, cette thèse a pu envisager deux extensions à SKATE. La première extension permet d'optimiser non seulement les assignations de tâches, mais aussi le nombre d'agents à considérer. Pour cela, cette thèse développe deux méthodes qui permettent d'optimiser à la fois le nombre d'agents (économie de ressources pour le fournisseur de services) tout en garantissant la satisfaction des utilisateurs (temps d'attente avant réalisation d'une tâche). La deuxième extension couple SKATE avec des outils de calcul vérifiable, permettant d'une part aux agents de vérifier que l'assignation des tâches a été correctement effectuée par le serveur central, et d'autre part de contrer des attaques cyber-physiques qu'un réseau d'agents mobiles pourrait subir dans des environnements hostiles, par exemple This thesis is set in the context of online multi-agent multi-task allocation, aiming to efficiently coordinate a set of agents (resources) to distribute tasks among them. As an application example, we can cite cases where clients make requests to a service provider who seeks the best distribution of tasks among its set of agents: taxis responding to customer demands or robots ensuring the delivery of parcels.Unlike the offline framework, which assumes full knowledge of the allocation problem to be solved before the start of the allocation, in the online framework, tasks arrive over time and must be allocated dynamically. This online optimization framework presents several challenges. Firstly, the repeated allocation of tasks to agents is an NP-hard problem, whose solution must be found in a limited time, sometimes very short. Secondly, knowledge about the arrival of future tasks (e.g., arrival time and location) is generally modest, making long-term reasoning difficult (i.e., optimizing the positioning of agents for long-term planning). Finally, the size of the problem to be handled in terms of agents and tasks can be substantial, especially in a realistic setting where finding a solution within a limited time can sometimes be compromised.In this context, this thesis proposes various contributions. Firstly, this thesis proposes a proactive approach that anticipates the availability of agents in the near future to achieve efficient coordination (i.e., minimizing the distance traveled by agents and the time they remain idle). This proactive approach has been compared to a classic reactive approach. The results obtained in two benchmark problems, one synthetic and the other based on real data, show that the proactive method achieves better results in terms of costs and the number of tasks allocated to agents compared to a reactive approach, while reducing the idle time of resources. Despite the encouraging results obtained, the proposed method has scalability limitations in our real-data-based benchmark problem. To address this limitation, this thesis proposes a second approach that develops a multi-agent multi-task allocation meta-heuristic called SKATE - Successive Rank-based Task Assignment for Proactive Online Planning, enabling scalability. SKATE allows for handling problems with thousands of agents and tasks, obtaining effective solutions in a limited time. SKATE shows good results in terms of the cost of the solutions found for such a scale of agents and tasks when compared to classical methods in the literature, such as a genetic algorithm or integer linear programming. Thanks to these results, this thesis subsequently considered two extensions to SKATE. The first extension optimizes not only task assignments but also the number of agents to consider. To achieve this, this thesis develops two methods that optimize both the number of agents (resource savings for the service provider) while ensuring user satisfaction (waiting time before task completion). The second extension couples SKATE with verifiable computing tools, allowing agents to verify that task assignment has been correctly performed by the central server and countering cyber-physical attacks that a network of mobile agents could face in hostile environments, for example

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Ben, Hmida Faten. "Evaluation des performances des systèmes multi-agents." Thesis, Bordeaux 1, 2013. http://www.theses.fr/2013BOR15200/document.

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Cette thèse s’intéresse à la question de l’évaluation des Systèmes Multi-Agents (SMA). Les caractéristiques propres que possèdent ces derniers, notamment en termes d’autonomie, de distribution, de dynamique et de socialité, ont grandement contribué à l’élargissement de leurs champs d’application, mais en contrepartie, elles ont rendu leur analyse plus ardue. Ainsi, les méthodes d’évaluation dans les systèmes informatiques classiques s’avèrent insuffisantes à analyser les SMA, étant donné qu’elles ne tiennent pas compte de leurs spécificités. L’objectif de cette thèse consiste donc à proposer une approche générique pour l’évaluation des SMA en se basant sur la mesure de leurs caractéristiques fonctionnelles. A cet effet, le besoin de disposer d’informations sur l’exécution du système à évaluer est manifeste. C’est dans ce cadre qu’une nouvelle approche d’observation des SMA est proposée. Les résultats de ces observations sont exploités pour construire une abstraction du système sous forme d’un modèle, lequel est étudié pour définir les mesures de performances. L’analyse se focalise sur deux caractéristiques essentielles, à la base de la dynamique et de la socialité des SMA : la communication et l’organisation. Les expérimentations de la solution proposée portent sur deux applications multi-agents. La première est une application de diagnostic des pannes dans un environnement industriel et la seconde est une application de pilotage et de gestion de la production dans les chaînes logistiques This thesis focuses on the issue of MultiAgent Systems (MAS) evaluation. The MAS own characteristics, namely autonomy, distribution, dynamicity and sociality, have greatly contributed to the expansion of their application scope; but in return they made their analysis more difficult. Thus, evaluation methods in classic computer systems are insufficient to analyse MAS, since they do not take into account their specificities. The objective of this thesis is to provide a generic approach for the evaluation of MAS by measuring their functional characteristics. To this end, the need for information about the execution of the system to be evaluated is evident. In this context, a new approach to observe MAS is proposed. The results of these observations are exploited to build an abstraction model of the system which is studied in order to define performance metrics. The analysis focuses on two key characteristics, at the basis on the dynamics and sociality in MAS: communication and organization. The experiments of the proposed solution are performed on two multiagent applications. The first is an application of fault diagnosis in an industrial environment and the second is an application of control and production planning in supply chains

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Galland, Stéphane. "Méthodologie et outils pour la simulation multiagent dans des univers virtuels." Habilitation à diriger des recherches, Université de Franche-Comté, 2013. http://tel.archives-ouvertes.fr/tel-00936334.

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La modélisation de la dynamique des piétons, des cyclistes et des conducteurs de véhicules est d'un grand intérêt théorique et pratique. Au cours des deux dernières décennies, la Recherche dans un large éventail de domaines tels que l'infographie, la physique, la robotique, les sciences sociales, la sécurité et les systèmes de formation a créé des simulations impliquant des individus de type hétérogènes. Deux grands types de simulation d'individus dans un univers virtuel peuvent généralement être distingués selon qu'elles cherchent à atteindre : un haut niveau de réalisme de comportement (simulation pour la sécurité ou les sciences sociales) ou une visualisation de haute qualité (productions de films, de jeux vidéos, d'outils de réalité virtuelle). Dans la première catégorie, les résultats de simulation sont généralement cohérents avec les observations réalisées sur la population réelle et peuvent servir de base à des études théoriques pour l'évaluation et la prévision du comportement des individus. Dans la seconde catégorie, les modèles de comportement ne sont pas la priorité et ne correspondent pas quantitativement au monde réel. Cependant, les individus sont des personnages en 3D entièrement animés et les utilisateurs de l'application peuvent avoir un degré élevé d'interaction avec les éléments de la simulation. Les recherches et les applications récentes tendent à unifier ces deux domaines, en particulier dans le domaine des systèmes de formation où les deux aspects sont nécessaires pour une formation efficace. Dans ce cadre, les systèmes multiagents sont utilisés pour modéliser les populations d'individus. Ils forment un paradigme prometteur pour la conception de logiciels complexes. En effet, ce paradigme propose de nouvelles stratégies pour analyser, concevoir et implémenter de tels systèmes. Les systèmes multiagents sont considérés comme des sociétés composées d'entités autonomes et indépendantes, appelées agents, qui interagissent en vue de résoudre un problème ou de réaliser collectivement une tâche. Les systèmes multiagents peuvent être considérés comme un outil viable pour la modélisation et la simulation de systèmes complexes, et notamment les systèmes de simulation d'individus dans un univers virtuel. Nous proposons un métamodèle organisationnel et holonique permettant de modéliser ces systèmes multiagents. L'approche organisationnelle permet de décomposer le système en unités comportementales appelées rôles. L'approche holonique permet de composer le système en un ensemble d'agents, eux-mêmes, pouvant être décomposés en un ensemble d'agents, et ainsi de suite. Ce métamodèle est utilisé comme la base de notre processus méthodologique, appelé ASPECS, qui guide les scientifiques et les experts d'un domaine dans la modélisation et la construction d'un modèle d'un SMA représentant un système complexe. Sur la base du métamodèle organisationnel et holonique, nous proposons des modèles d'environnement et de groupes d'individus constituant un système de grande échelle spatiale et avec une large population d'individus. Ces modèles sont utilisés pour la simulation d'individus et de foules dans des univers virtuels. L'une des particularités intéressantes de nos modèles est leur conception multiniveau. Nous proposons des modèles de décomposition hiérarchique dynamique pour l'environnement et pour la population. Durant le processus de simulation, il devient alors possible de sélectionner les niveaux permettant d'atteindre le meilleur compromis entre la qualité des résultats produits par la simulation et les performances de calculs pour obtenir ces résultats. Les modèles présentés dans ce mémoire ont été appliqués à la simulation de foule et de trafic dans le cadre de contrats de recherche dont certains sont abordés dans ce document : simulation du réseau urbain de bus de Belfort, simulation de foules dans un centre ville de Belfort, simulation du covoiturage dans les Flandres.

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Suárez, Barón Silvia Andrea. "Dynamic task allocation and coordination in cooperative multi-agent environments." Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/7754.

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La coordinació i assignació de tasques en entorns distribuïts ha estat un punt important de la recerca en els últims anys i aquests temes són el cor dels sistemes multi-agent. Els agents en aquests sistemes necessiten cooperar i considerar els altres agents en les seves accions i decisions. A més a més, els agents han de coordinar-se ells mateixos per complir tasques complexes que necessiten més d'un agent per ser complerta. Aquestes tasques poden ser tan complexes que els agents poden no saber la ubicació de les tasques o el temps que resta abans de que les tasques quedin obsoletes. Els agents poden necessitar utilitzar la comunicació amb l'objectiu de conèixer la tasca en l'entorn, en cas contrari, poden perdre molt de temps per trobar la tasca dins de l'escenari. De forma similar, el procés de presa de decisions distribuït pot ser encara més complexa si l'entorn és dinàmic, amb incertesa i en temps real. En aquesta dissertació, considerem entorns amb sistemes multi-agent amb restriccions i cooperatius (dinàmics, amb incertesa i en temps real). En aquest sentit es proposen dues aproximacions que permeten la coordinació dels agents. La primera és un mecanisme semi-centralitzat basat en tècniques de subhastes combinatòries i la idea principal es minimitzar el cost de les tasques assignades des de l'agent central cap als equips d'agents. Aquest algoritme té en compte les preferències dels agents sobre les tasques. Aquestes preferències estan incloses en el bid enviat per l'agent. La segona és un aproximació d'scheduling totalment descentralitzat. Això permet als agents assignar les seves tasques tenint en compte les preferències temporals sobre les tasques dels agents. En aquest cas, el rendiment del sistema no només depèn de la maximització o del criteri d'optimització, sinó que també depèn de la capacitat dels agents per adaptar les seves assignacions eficientment. Addicionalment, en un entorn dinàmic, els errors d'execució poden succeir a qualsevol pla degut a la incertesa i error de accions individuals. A més, una part indispensable d'un sistema de planificació és la capacitat de re-planificar. Aquesta dissertació també proveeix una aproximació amb re-planificació amb l'objectiu de permetre als agent re-coordinar els seus plans quan els problemes en l'entorn no permeti la execució del pla. Totes aquestes aproximacions s'han portat a terme per permetre als agents assignar i coordinar de forma eficient totes les tasques complexes en un entorn multi-agent cooperatiu, dinàmic i amb incertesa. Totes aquestes aproximacions han demostrat la seva eficiència en experiments duts a terme en l'entorn de simulació RoboCup Rescue. Distributed task allocation and coordination have been the focus of recent research in last years and these topics are the heart of multi-agent systems. Agents in these systems need to cooperate and consider the other agents in their actions and decisions. Moreover, agents may have to coordinate themselves to accomplish complex tasks that need more than one agent to be accomplished. These tasks may be so complicated that the agents may not know the location of them or the time they have before the tasks become obsolete. Agents may need to use communication in order to know the tasks in the environment, otherwise, it may take a long time to find the tasks into the scenario. Similarly, the distributed decisionmaking process may be even more complex if the environment is dynamic, uncertain and real-time. In this dissertation, we consider constrained cooperative multi-agent environments (dynamic, uncertain and real-time). In this regard, we propose two approaches that enable the agents to coordinate themselves. The first one is a semi-centralized mechanism based on combinatorial auction techniques and the main idea is minimizing the cost of assigned tasks from the central agent to the agent teams. This algorithm takes into account the tasks' preferences of the agents. These preferences are included into the bid sent by the agent. The second one is a completely decentralized scheduling approach. It permits agents schedule their tasks taking into account temporal tasks' preferences of the agents. In this case, the system's performance depends not only on the maximization or the optimization criterion, but also on the agents' capacity to adapt their schedule efficiently. Furthermore, in a dynamic environment, execution errors may happen to any plan due to uncertainty and failure of individual actions. Therefore, an indispensable part of a planning system is the capability of replanning. This dissertation is also providing a replanning approach in order to allow agents recoordinate his plans when the environmental problems avoid fulfil them. All these approaches have been carried out to enable the agents to efficiently allocate and coordinate all their complex tasks in a cooperative, dynamic and uncertain multi-agent scenario. All these approaches have demonstrated their effectiveness in experiments performed in the RoboCup Rescue simulation environment.

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Carabelea, Cosmin. "Raisonner sur l'autonomie d'un agent au sein de systèmes multi-agents ouverts : une approche basée sur les relations de pouvoir." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 2007. http://tel.archives-ouvertes.fr/tel-00786141.

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Nous prenons le point de vue d'un agent sur le point d'entrer dans une organisation multi-agent, où il aura à choisir parmi plusieurs rôles disponibles. Notre objectif est de donner à cet agent les moyens d'évaluer avant d'entrer dans une organisation les implications que cette action aura sur ses capacités de satisfaire les désirs de son utilisateur. Quand il entre dans une organisation, un agent devient le sujet de plusieurs contraintes imposées par des entités externes (d'autres agents, l'organisation même, la société). Comme le montre cette thèse, l'autonomie sociale de décision est une caractéristique d'un agent, qui est directement liée à ces contraintes sociales. En conséquence, nous basons l'évaluation faite par un agent des contraintes qui lui sont imposées sur le concept d'autonomie. Cette approche est illustrée à l'aide d'un scénario d'intelligence ambiante qui a été implémenté et déployé sur des objets portables.

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Hoang, Thi Thanh Ha. "Un modèle multi-agent récursif générique pour simplifier la supervision de systèmes complexes artificiels décentralisés." Thesis, Grenoble, 2012. http://www.theses.fr/2012GRENM033/document.

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L'observation des systèmes complexes artificiels à grande échelle est difficile en raison de leur dimension et de leur ouverture. Cette thèse propose le modèle SMA-R (Système Multi-Agent Récursif) basé sur la récursivité pour l'observation multi-niveau des systèmes complexes artificiels. À partir d'un Système Multi-Agent donné, ce modèle est capable de construire une représentation abstraite multi-niveau. Le modèle d'agent récursif proposé possède un module contenant les connaissances, les capacités et le contexte de récursivité; un module pour observer les changements; deux mécanismes pour construire ou détruire les niveaux abstraits; un module d'interaction récursive prenant en charge des comportements collectifs et individuels. Pour appliquer ce modèle à des SMA physiquement décentralisés, nous avons proposé une architecture générique décentralisée d'agents récursifs en adoptant les concepts du modèle OSI qui offre en avant les capacités que nous cherchons: multi niveau, encapsulation, échange de messages virtuels et physiques... Un framework décentralisé générique a été développé permettant aux agents réels de construire les niveaux d'observation. Ce framework est appliqué à l'observation d'un réseau de capteurs sans fil Observation of large scale artificials systems is difficult because of their dimension and their openness. This thesis proposes a model SMA-R (Recursive Multi-Agent Systems) based on recursion for multi-level observation of artificial complex systems. From a given SMA, this model is able to build multi-level of abstractions. The model's agent has a module containning knowledge, skills and context of recursion, an eye to observe changes; two mechanisms to build or destroy an abstract level, a module of recursive interaction to support collective and individual behaviors. For applying this model to SMA physically decentralized, we proposed a generic decentralized architecture for recursive agent by adopting the concepts of the OSI model which offerts forward capabilities that we look for: multi-level encapsulation, exchange of virtual and physical messages ... A generic decentralized framework was developed allowing applicatives agents to build multi-levels observation. This framework is applied to the observation of a wireless sensor network

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Dissertations / Theses on the topic 'Autonomous agents and multiagent systems'

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