The amount of information on the World Wide Web (WWW) is rapidly growing in pace and topic diversity. This has made it increasingly difficult, and often frustrating, for information seekers to retrieve the content they are looking for as information retrieval systems (e.g., search engines) are unable to decipher the relevance of the retrieved information as it pertains to the information they are searching for. This issue can be decomposed into two aspects: 1) variability of information relevance as it pertains to an information seeker. In other words, different information seekers may enter the same search text, or keywords, but expect completely different results. It is therefore, imperative that information retrieval systems possess an ability to incorporate a model of the information seeker in order to estimate the relevance and context of use of information before presenting results. Of course, in this context, by a model we mean the capture of trends in the information seeker's search behaviour. This is what many researchers refer to as the personalized search. 2) Information diversity. Information available on the World Wide Web today spans multitudes of inherently overlapping topics, and it is difficult for any information retrieval system to decide effectively on the relevance of the information retrieved in response to an information seeker's query. For example, the information seeker who wishes to use WWW to learn about a cure for a certain illness would receive a more relevant answer if the search engine was optimized into such domains of topics. This is what is being referred to in the WWW nomenclature as a 'specialized search'. This thesis maintains that the information seeker's search is not intended to be completely random and therefore tends to portray itself as consistent patterns of behaviour. Nonetheless, this behaviour, despite being consistent, can be quite complex to capture. To accomplish this goal the thesis proposes a Multi-Agent Personalized Information Retrieval with Specialization Ontology (MAPIRSO). MAPIRSO offers a complete learning framework that is able to model the end user's search behaviour and interests and to organize information into categorized domains so as to ensure maximum relevance of its responses as they pertain to the end user queries. Specialization and personalization are accomplished using a group of collaborative agents. Each agent employs a Reinforcement Learning (RL) strategy to capture end user's behaviour and interests. Reinforcement learning allows the agents to evolve their knowledge of the end user behaviour and interests as they function to serve him or her. Furthermore, REL allows each agent to adapt to changes in an end user's behaviour and interests. Specialization is the process by which new information domains are created based on existing information topics, allowing new kinds of content to be built exclusively for information seekers. One of the key characteristics of specialization domains is the seeker centric - which allows intelligent agents to create new information based on the information seekers' feedback and their behaviours. Specialized domains are created by intelligent agents that collect information from a specific domain topic. The task of these specialized agents is to map the user's query to a repository of specific domains in order to present users with relevant information. As a result, mapping users' queries to only relevant information is one of the fundamental challenges in Artificial Intelligent (AI) and machine learning research. Our approach employs intelligent cooperative agents that specialize in building personalized ontology information domains that pertain to each information seeker's specific needs. Specializing and categorizing information into unique domains is one of the challenge areas that have been addressed and various proposed solutions were evaluated and adopted to address growing information. However, categorizing information into unique domains does not satisfy each individualized information seeker. Information seekers might search for similar topics, but each would have different interests. For example, medical information of a specific medical domain has different importance to both the doctor and patients. The thesis presents a novel solution that will resolve the growing and diverse information by building seeker centric specialized information domains that are personalized through the information seekers' feedback and behaviours. To address this challenge, the research examines the fundamental components that constitute the specialized agent: an intelligent machine learning system, user input queries, an intelligent agent, and information resources constructed through specialized domains. Experimental work is reported to demonstrate the efficiency of the proposed solution in addressing the overlapping information growth. The experimental work utilizes extensive user-centric specialized domain topics. This work employs personalized and collaborative multi learning agents and ontology techniques thereby enriching the queries and domains of the user. Therefore, experiments and results have shown that building specialized ontology domains, pertinent to the information seekers' needs, are more precise and efficient compared to other information retrieval applications and existing search engines.

En esta tesis se propone el uso de agentes inteligentes en entornos de aprendizaje en línea con el fin de mejorar la asistencia y motivación del estudiante a través de contenidos personalizados que tienen en cuenta el estilo de aprendizaje del estudiante y su nivel de conocimiento. Los agentes propuestos se desempeñan como asistentes personales que ayudan al estudiante a llevar a cabo las actividades de aprendizaje midiendo su progreso y motivación. El entorno de agentes se construye a través de una arquitectura multiagente llamada MASPLANG diseñada para dar soporte adaptativo (presentación y navegación adaptativa) a un sistema hipermedia educativo desarrollado en la Universitat de Girona para impartir educación virtual a través del web.Un aspecto importante de esta propuesta es la habilidad de construir un modelo de estudiante híbrido que comienza con un modelo estereotípico del estudiante basado en estilos de aprendizaje y se modifica gradualmente a medida que el estudiante interactúa con el sistema (gustos subjetivos). Dentro del contexto de esta tesis, el aprendizaje se define como el proceso interno que, bajo factores de cambio resulta en la adquisición de la representación interna de un conocimiento o de una actitud. Este proceso interno no se puede medir directamente sino a través de demostraciones observables externas que constituyen el comportamiento relacionado con el objeto de conocimiento. Finalmente, este cambio es el resultado de la experiencia o entrenamiento y tiene una durabilidad que depende de factores como la motivación y el compromiso.El MASPLANG está compuesto por dos niveles de agentes: los intermediarios llamados IA (agentes de información) que están en el nivel inferior y los de Interfaz llamados PDA (agentes asistentes) que están en el nivel superior. Los agentes asistentes atienden a los estudiantes cuando trabajan con el material didáctico de un curso o una lección de aprendizaje. Esta asistencia consiste en la recolección y análisis de las acciones de los estudiantes para ofrecer contenidos personalizados y en la motivación del estudiante durante el aprendizaje mediante el ofrecimiento de contenidos de retroalimentación, ejercicios adaptados al nivel de conocimiento y mensajes, a través de interfaces de usuario animadas y atractivas. Los agentes de información se encargan del mantenimiento de los modelos pedagógico y del dominio y son los que están en completa interacción con las bases de datos del sistema (compendio de actividades del estudiante y modelo del dominio).El escenario de funcionamiento del MASPLANG está definido por el tipo de usuarios y el tipo de contenidos que ofrece. Como su entorno es un sistema hipermedia educativo, los usuarios se clasifican en profesores quienes definen y preparan los contenidos para el aprendizaje adaptativo, y los estudiantes quienes llevan a cabo las actividades de aprendizaje de forma personalizada. El perfil de aprendizaje inicial del estudiante se captura a través de la evaluación del cuestionario ILS (herramienta de diagnóstico del modelo FSLSM de estilos de aprendizaje adoptado para este estudio) que se asigna al estudiante en su primera interacción con el sistema. Este cuestionario consiste en un conjunto de preguntas de naturaleza sicológica cuyo objetivo es determinar los deseos, hábitos y reacciones del estudiante que orientarán la personalización de los contenidos y del entorno de aprendizaje. El modelo del estudiante se construye entonces teniendo en cuenta este perfil de aprendizaje y el nivel de conocimiento obtenido mediante el análisis de las acciones del estudiante en el entorno.

In recent years many people have built Personal Assistant Agents, Information Agents and the like, and have simply added them to the operating system as auxiliary applications, without regard to architecture. This thesis argues that an agent architecture, one designed as a sophisticated representation of an individual user, should be embedded deep in the device system software, with at least equal status to the GUI – the graphical user interface. A sophisticated model of the user is then built, drawing upon contemporary Analytical Psychology – the Psychology of Subselves. The Shadowboard Agent architecture is then built upon that user model, drawing both structural and computational implications from the underlying psychology. An XML DTD file named Shadowboard.dtd is declared as a practical manifestation of the semantics of Shadowboard. An implementation of the Shadowboard system is mapped out, via a planned conversion of two existing integrated systems: SlimWinX, an event-driven GUI system; and XSpaces, an object-oriented tuplespace system with Blackboard-like features. The decision making mechanism passes logic terms and contraints between the various sub-agent components (some of which take on the role of Constraint Solvers), giving this agent system some characteristics of a Generalised Constraint Solver. A Shadowboard agent (built using the system) consists of a central controlling autonomous agent named the Aware Ego Agent, and any number of sub-agents, which collectively form an integrated but singular whole agent modelled on the user called the Digital Self. One such whole-agent is defined in a file named DigitalSelf.xml – which conforms to the schema in Shadowboard.dtd - which offers a comprehensive and generic representation of a user’s stance in a 24x7 network, in particular - the Internet. Numerous types of Shadowboard sub-agents are declared.

Cette thèse présente une contribution sur les problèmes de contrôle de réseaux d'irrigations en tenant compte des contraintes de communication grâce à une approche multicouches d’intelligence distribuée. Les analyses détaillées de chaque couche avec les résultats analytiques et les simulations seront décrites dans les différents chapitres. Ils mettent l'accent sur l'intérêt de l'approche multicouches, plus précisément sur son efficacité et sa fiabilité pour la supervision, l'optimisation multi-objectifs et le contrôle coopératif distribué sur des systèmes complexes de transport d'eau.La première couche analysé est le réseau hydraulique composé de canaux d’écoulements à surface libre, de sous-réseaux maillés de tuyaux sous pression et des structures hydrauliques (pompes vannes, ..). En intégrant les équations de Saint-Venant pour décrire l’écoulement physique des fluides en surface libre et la méthode Lattice Boltzmann pour la simulation du fluide, nous obtenons un modèle non linéaire discret pour les canaux à surface libre. Les structures hydrauliques sont généralement traitées comme des limites internes des biefs (tronçons) et modélisées par des relations entre les variables de flux et de pression.Permettant l'échange d'informations entre les éléments du système de contrôle, le réseau de communication sera considéré comme la deuxième couche. La résolution des problèmes d’hétérogénéités des systèmes et des communications (par exemple les retards de diffusion dans le réseau, la perte de paquets, la consommation d'énergie) sera étudié en introduisant une architecture de réseau hybride avec un routage dynamique basé sur les exigences de Qualité de Service (QoS) des applications de contrôle. Pour le routage dynamique dans le réseau, une composition pondérée de certaines métriques standards est proposée afin que le protocole de routage utilisant cette métrique composite converge sans boucle avec une « route » optimum. Grâce à différents scénarios de simulation, plusieurs critères de performance du réseau ont été évalués. La comparaison des résultats de simulation permet de valider l'intérêt de cette approche de composition pour le routage dynamique.Une troisième couche propose un système de contrôle réactif optimal développé pour la régulation du réseau d'irrigation dans un modèle étendue à grande échelle : Distributed Cooperative Model Predictive Control (DCMPC). Cette partie aborde la mise en œuvre de différentes stratégies de contrôle (centralisées, décentralisées et distribuées) et intègre la communication coopérative entre les contrôleurs MPC locaux afin d’améliorer les performances global es du système. La gestion de la divergence dans l'échange d'informations entre les contrôleurs est considérée comme un problème de consensus et résolue en utilisant un protocole de consensus asynchrone. Cette approche du contrôle distribué basée sur le paradigme des systèmes multi-agents, fournit une solution garantissant que tous les contrôleurs aient une vue cohérente de certaines valeurs des données nécessaires pour le calcul de décision. Un cas d’application sur un canal d'irrigation est étudié dans les simulations. La comparaison des résultats de simulations valide les avantages de l'approche du contrôle distribué coopératif par rapport aux autres stratégies de contrôle. / This thesis presents control problems of irrigation network with communication constraints and a multi-layer approach to solve these problems in a distributed manner. Detailed discussions of each layer with analytical and simulation results are described throughout several chapters. They emphasize the potential interest of the multi-layer approach, more precisely its efficiency and reliability for supervision, multi-objective optimization and distributed cooperative control of complex water transport systems. Conventionally, the first layer to be considered is the hydraulic network composed of free-surface channels, hydraulic structures and mesh subnetwork of pressurized pipes. By coupling the Saint-Venant equations for describing the physics of free-surface fluid and the Lattice Boltzmann method for the fluid simulation, a discrete-time nonlinear model is obtained for channel reaches. The hydraulic structures are usually treated as internal boundaries of reaches and modeled by algebraic relationships between the flow and pressure variables. To enable the exchange of information among the control system’s components, a communication network is considered in the second layer. Solving challenging problems of heterogeneous devices and communication issues (e.g., network delay, packet loss, energy consumption) is investigated in this thesis by introducing a hybrid network architecture and a dynamic routing design based on Quality of Service (QoS) requirements of control applications. For network routing, a weighted composition of some standard metrics is proposed so that the routing protocol using the composite metric achieves convergence, loop-freeness and path-optimality properties. Through extensive simulation scenarios, different network performance criteria are evaluated. The comparison of simulation results can validate the interest of this composition approach for dynamic routing. Finally, the third layer introduces an optimal reactive control system developed for the regulatory control of large-scale irrigation network under a Distributed Cooperative Model Predictive Control (DCMPC) framework. This part discusses the implementation of different control strategies (e.g., centralized, decentralized, and distributed strategies) and how the cooperative communication among local MPC controllers can be included to improve the performance of the overall system. Managing divergent (or outdated) information exchange among controllers is considered in this thesis as a consensus problem and solved by an asynchronous consensus protocol. This approach based on the multi-agent system paradigm to distributed control requires each controller to agree with its neighbors on some data values needed during action computation. For simulations, a particular benchmark of an irrigation channel is considered. The comparison of simulation results validate the benefits of the distributed cooperative control approach over other control strategies.

Le travail présenté dans ce mémoire contribue au domaine de l’entreprise étendue et le développement des systèmes d’informations distribués. et le développement des systèmes d’informations distribués. C’est bien évidemment un sujet d’étude important pour la communauté Logistique (chaîne logistique), mais aussi pour la communauté Génie logiciel. C’est dans cette perspective que se situent les objectifs de proposer une modélisation de la chaîne logistique globale dans un environnement de transport intermodal de porte à porte en vue de résoudre les problèmes : (i) d’interfaces entre les différents acteurs intervenants le long de la chaîne et (ii) de rupture des charges engendrés par les opérations de transfert de marchandises d’un mode de transport à l’autre. Ainsi, l’amélioration de performance de la chaine logistique dépend fortement du niveau de coopération et de coordination, et surtout du partage et de la validité des informations et des connaissances, entre ces différents acteurs de la chaîne (organisateur du transport, transitaire, fournisseur, etc.). L’applicatif se situe dans le corridor de la vallée de Seine. Le travail s’inscrit dans le projet APLOG (Amélioration et Performance de la LOgistique Globale) financé par la région Haute Normandie. / The work presented in this thesis contributes to the field of the extended enterprise and the development of distributed information systems. This is obviously an important subject of study for the logistics community (supply chain), but also for the software engineering community. It is in this context that the objectives are to provide a model of global supply chain in an intermodal environment door to door service to solve the problems: (i) interfaces between the different actors involved along the chain and (ii) trans-loading operations generated by the goods transfer operations from one mode of transport to another. Thus, improved performance of the supply chain depends heavily on the level of cooperation and coordination, and especially sharing and validity of information and knowledge between the different actors in the chain (transport organizer, forwarding, Supplier, etc.). The application is located in the corridor of the Seine valley. The work is part of the project APLOG (Performance Improvement and global logistics) financed by the Haute Normandie region.

La gestion de l'eau peut être un domaine complexe, incertain et conflictuel. Dans différentes régions du monde il se confronte à de nombreux problèmes, tel que la disparité des intérêts liés à la ressource de l’eau, plusieurs décideurs, des réseaux administratives complexes, la distribution d'eau inefficace, divers événements socio-politiques et le changement climatique. Par conséquent, la prise de décision a lieu dans un système fortement interconnecté, dans lequel ni les ramifications décisionnels ni la complexité de ses impacts peuvent être négligés. Dans la région des Pouilles, la rareté de l'eau est le principal problème croissant qui touche les communautés humaines et plus qu’humaines.La pénurie d'eau génère la nécessité d'améliorer les processus décisionnels collaboratifs avec agents multiples. Les chercheurs suggèrent que la «tragédie des communs» pourrait être évitée si une ressource partagée était gérée de manière collective. Cela nécessite le développement d'outils dynamiques d’aide à la décision. Ceux-ci devraient être capables d'intégrer les différents cadres de problèmes détenues par les décideurs, de clarifier les différences entre les cadres, de soutenir la création d'un processus collaboratif pour la structuration d’un problème et de fournir des plates-formes communes et des espaces d'interaction.À cet égard, nous avons construit un espace d'interaction dynamique (DIS), mettant en évidence les points critiques opératoires et permettant aux analystes d'identifier une définition commune du problème. Les nouveaux défis de la collecte et de l'échange de connaissances et de la représentation des concepts structurés peuvent être résolus par une approche combinée. Les systèmes multi-agents joints aux systèmes dynamiques pourraient fournir des alternatives non conventionnelles qui utilisent des composants physiques et sociales, avec une attention particulière sur les comportements individuels et collectifs dans la gestion des ressources avec plusieurs décideurs.Dans notre étude de cas, le modèle a été utilisé comme une plate-forme pour la modélisation des organisations multi-agents, afin de soutenir la prise de décision collective dans la gestion de l'eau. Le modèle est capable de représenter un système de gestion de l'eau distribuée complexe, où les comportements simulés sont basées sur des observations sur le terrain et sur la participation des parties prenantes. De plus, l'approche de système multi-agents permet l'interaction et la formalisation des comportements des usagers de l'eau dans le processus de gestion. Une modélisation type systèmes dynamiques dans un environnement d'interaction entre agents de décision, nous permet d’intégrer explicitement les différents cadres et de simuler les interactions lors de l'adoption d'une nouvelle politique. Le modèle peut montrer comment la compréhension limitée de l'espace d'interaction affecte les actions suivies par chacun des décideurs et, enfin, comment elle pourrait conduire à des mécanismes de résistance systémique. En conclusion, le résultat est l’image la plus riche possible de la situation du problème existant, qui traite de la gestion de l'eau d'irrigation dans les systèmes agricoles. / Water resource management can be a complex, uncertain and conflictual domain. It faces numerous problems in many regions of the world, such as the disparity of interests associated with the water resource, multiple decision makers, complex networks of administration, inoperative water distribution, various socio-political events and climate change. Consequently, environmental decision-making takes place in a highly interconnected system, in which neither the decisional ramifications nor the complexity of its impacts can be neglected. In the Apulia Region, water scarcity is the main rising problem and is affecting human and more-than-human communities.Water scarcity generates the need to enhance collaborative multi-agent decision-making processes. Researchers suggest that the “tragedy of commons” could be avoided when a shared resource is at stake, provided that communities interact and operate in a collective way and avoid, for example, the market rules constraints. This requires the development of dynamic decision-aiding tools. They should be capable to integrate the different problem frames held by the decision makers, to clarify the differences among those frames, to support the creation of a collaborative problem structuring process and to provide shared platforms and interaction spaces.In this regard, we built a dynamic interaction space (DIS), highlighting the operative criticalities and allowing the analysts to identify a shared problem definition. The emerging issues of gathering and exchanging knowledge and representing structured concepts can be solved through a combined approach. Multi-agent systems joined with system dynamics can provide unconventional alternatives that use physical and social components, with a particular focus on individual and collective behaviours in resource management with multiple decision makers.In our case study, the model was used as a platform for modelling multi-agent organizations, in order to support collective decision-making in water management. The model is capable of representing a distributed complex water management system, where simulated behaviours are based on field observations and on the participation of stakeholders. What is more, the multi–agent system approach enables the interaction and allows to formalize theIrene Pluchinotta – “Multi-Agent Modelling For Distributed Intelligent Decision In Water Management”iibehaviours of water users in the management process. A system dynamics modelling in an environment of interacting decision agents, allows us to explicitly consider the different frames and to simulate interactions when adopting a new policy. The model can showcase how the limited understanding of the interaction space affects the actions followed by each decision-makers and, finally, how it could lead to policy resistance mechanisms. In conclusion, the result is the richest possible picture of the existing problem situation that deals with irrigation water management in agricultural systems.

La croissance exponentielle dans l’utilisation du réseau Internet ainsi que l’apparition de nouveaux types d’applications ont augmenté les contraintes du réseau en termes de sécurité. Depuis quelques années, les techniques biométriques ont prouvé une grande précision et fiabilité et ont été utilisées dans plusieurs domaines afin de sécuriser l’accès à différentes ressources. Des solutions intégrant des agents et des systèmes multi-agents (SMA) ont aussi prouvé leur efficacité pour la résolution de nombreux problèmes dans les réeaux. Nous proposons un modèle « IrisCrptoAgentSystem » (ICAS) basé sur la méthode biométrique pour l’authentification utilisant l’iris de l’œil et la méthode de cryptographie asymétrique utilisant l’algorithme « Rivest-Shamir-Adleman » (RSA), et en intégrant des agents. Ce modèle doit assurer un accès sécurisé aux informations et garantir la protection des informations confidentielles. Notre travail porte sur la mise en place de nouvelles méthodes dans le modèle d’authentification biométrique afin de donner plus d’efficacité à notre modèle ICAS. Nous introduisons des aspects prétopologiques dans l’élaboration de la hiérarchie indexée pour classer les gabarits DHVA. Notre approche consiste à améliorer les méthodes relatives à la localisation des contours externe et interne de l’iris. / The exponential growth in the use of the Internet as well as the emergence of new types of applications has increased the network’s constraints in terms f security. Fort the last several years, biometric techniques have proven their applicability and reliability in providing secure access to shared resources in different domains. Furthermore, software agents and multi-agent systems (MAS) have evidently been efficient in resolving several problems in network. Therefore, the aim of this research is to propose a model “IrisCryptoAgentSystem” (ICAS) that is based on a biometric method for authentication using the iris of the eyes and an asymmetric cryptography method using “Rivest-Shamir-Adleman” (RSA) in an agent-based architecture. This model should provide secure access to information and ensure the protection of confidential information. Therefore, our work focuses on the development of new methods in biometric autheitcation in order to provide greater efficiency in the ICAS model. We introduce pretopological aspects in the development of the indexed hierarchy to classify DHVA templates. Our approach aims to improve the existing methods for the localization of the external and the internal edges of the iris.

[pt] Consciência de software (software awareness) tornou-se um requisito importante na construção de sistemas com capacidade de autoadaptação. Para que aplicações de software possam melhor se adaptar a mudanças nos diversos ambientes em que operam, ter consciência (no sentido de perceber e entender esses ambientes e a seu próprio funcionamento nestes ambientes) é fundamental. Entretanto, mesmo em um nível básico aplicado a software, consciência é um requisito difícil de definir. Nosso trabalho propõe a organização de um catálogo para o requisito de consciência de software, com mecanismos para instanciação e uso do conhecimento armazenado neste catálogo na modelagem e implementação de software para problemas onde a autoadaptação, e por consequência consciência, sejam requisitos chave. / [en] Software awareness has become an important requirement in the construction of self-adaptive systems. As such, the software should better adapt to changes in the various environments in which they operate, be aware of (in the sense of perceiving and understanding) these environment and be aware of its own operation in these environments. However, even at a basic level applied to software, awareness is a requirement difficult to define. Our work proposes the creation of a catalog to the awareness requirement through non-functional requirements patterns (NFR patterns). We also propose mechanisms for enabling the instantiation and use of the knowledge about awareness, represented in this catalog.

Made available in DSpace on 2014-07-29T15:08:16Z (GMT). No. of bitstreams: 1 Dissertacao_Wildener_Monteiro.pdf: 504804 bytes, checksum: 182065e82ecb49614ac91a869030a772 (MD5) Previous issue date: 2011-02-10 / The goal of this dissertation is to make a methodological repetition of Duffy and Ochs's and Rouchier's works. Nonetheless, it tries to have a different focus. Among many theoreticaleconomical models which explain the emergence of money, there is one that distinguishes itself due to its simplicity, efficiency, and robustness: Kiyotaki-Wright's model. Therefore, some economists devoted themselves to apply this model in experiments with human beings and in computer simulations. Among those economists, Duffy and Ochs applied it later, correcting some flaws of the application process used by their predecessors. Duffy and Ochs's studies showed that Kiyotaki-Wright's model is actually valid for its purpose. However, besides all the efforts made, their agents were not able to achieve the foreseen equilibrium. In the same way, the French researcher Rouchier repeated methodologically the works of Duffy and Ochs while criticizing their implementation details. From this research, Rouchier creates other four sub-models in order to take her agents to the proposed equilibrium, obtaining partial success. In this dissertation, the computer system development platform is Swarm, especially created to multi-agent simulations and used, most of the time, in social and biological scope models. The agents' rationalization process is undertaken in trial and error way in accordance with the reinforcement learning technique, analyzing the answer given by the environment in each period. Finally, a new entity called Mediator is created to intermediate the relations between agents and mainly to pair them randomly. The obtained results are, in general, closer to the equilibrium when compared to the results of previous research. From them, some studies are made about the relation between the number of agents and the number of periods of simulation as values approximates the equilibrium. / O objetivo deste trabalho é realizar uma repetição metodológica dos trabalhos de Duffy, Ochs e Rouchier. Entretanto, ele possui um enfoque diferente. Dos vários modelos teóricoeconômicos que explicam o surgimento do dinheiro, um se destaca por sua simplicidade, eficiência e robustez: o modelo de Kiyotaki-Wright. Por este motivo, alguns economistas se propuseram a aplicar este modelo em experimentos com seres humanos e em simulações computacionais. Destes, Duffy e Ochs vieram pouco depois, corrigindo algumas falhas do processo de aplicação usado pelos que lhes antecederam. Os estudos de Duffy e Ochs mostraram que o modelo de Kiyotaki-Wright é realmente válido para aquilo a que se propõe. No entanto, apesar dos esforços empreendidos, seus agentes não conseguiram alcançar o equilíbrio previsto. Nesta mesma linha, a francesa Rouchier repetiu metodologicamente os trabalhos de Duffy e Ochs ao mesmo tempo em que criticava os detalhes de suas implementações. Ao aproveitar a pesquisa, Rouchier criou quatro outros sub-modelos na tentativa de levar seus agentes ao equilíbrio proposto, alcançando um sucesso parcial. No presente trabalho, a plataforma de desenvolvimento do sistema computacional é a Swarm, criada especificamente para simulações multi-agentes e usada, na maioria das vezes, em modelos dos campos social e biológico. O processo de racionalização dos agentes é dado na forma de tentativa e erro como rege a técnica de aprendizado por reforço. Ele analisa, em cada período, a resposta dada pelo ambiente. Finalmente, uma nova entidade chamada de Mediador é criada para intermediar as relações entre os agentes e, principalmente, para colocá-los em pares de forma aleatória. Os resultados alcançados são, em geral, mais próximos do equilíbrio quando comparados aos resultados das pesquisas anteriores. A partir deles, são feitos alguns estudos sobre a relação entre o número de agentes e o número de períodos da simulação com a aproximação dos valores para o equilíbrio.

Made available in DSpace on 2016-08-17T14:52:39Z (GMT). No. of bitstreams: 1 Heider Cristian Moura Quintao.pdf: 4191526 bytes, checksum: 3053fbdd9113f05514fce93fc176aa9e (MD5) Previous issue date: 2008-02-15 / When equipment failure occur in complex industrial plants, the automation and control system generates a great amount of alarms that can confuse the operators and lead them to take wrong decisions - the time for decision taking is very short and the amount of generated information is higher, being impossible for the operator read all of them before taking the correct decision. The new industrial systems have presented functionalities that try to minimize this deficiency presenting some support to the user, but still in an inefficient form. This work presents a proposal of an Alarm Management System based on Action Recommendation - SIGARA, a knowledge-based tool which aims supporting users of industrial control systems, when abnormal events occur. SIGARA is an action recommender multi-agent system, shaped on the basis of the described tasks and phases of the ONTORMAS ontology and MAAEM methodology. Beyond searching the solution of a problem of the real world in the industries, the proposed SIGARA presents some additional features not present on existing systems, as the application of information filtering techniques in different processing phases, and also the use of MAAEM and ONTORMAS in this new domain. / Quando ocorrem falhas de equipamentos em plantas industriais complexas, o sistema de automação e controle gera uma grande quantidade de alarmes que podem confundir os operadores e induzi-los a tomar decisões erradas. O tempo para a tomada de decisão é muito curto e a quantidade de informação gerada é muito grande, sendo impossível que o operador consiga ler todas antes de tomar a decisão correta. Os novos sistemas industriais têm apresentado funcionalidades que buscam minimizar essa deficiência apresentando algum suporte ao usuário, mas ainda de forma ineficiente. O presente trabalho apresenta como proposta um Sistema Informatizado de Gerenciamento de Alarmes baseado na Recomendação de Ações (SIGARA). É uma ferramenta baseada em conhecimento que objetiva suportar usuários de sistemas industriais de automação e controle, quando da ocorrência de alguma anomalia. O SIGARA é um sistema multiagente de recomendação de ações, modelado com base nas tarefas e fases descritas na ontologia ONTORMAS ( Ontology for Reusing Multi-agent Software ), conforme a metodologia MAAEM ( Multi-Agent Application Engineering Methodology ). Além de buscar a solução de um problema do mundo real presente nas indústrias, o SIGARA proposto apresenta alguns diferenciais frente aos existentes no mercado, como o uso de técnicas de filtragem de informação em várias etapas do processamento das informações, e também a aplicação da MAAEM e ONTORMAS que ainda não haviam sido utilizadas nesse domínio.