Dissertations / Theses on the topic 'Multi-agent system analysis'

Within today's privatised electricity industry, post-fault disturbance analysis is becoming an increasingly challenging prospect for protection engineers. Not only must they be proficient at operating a diverse range of data gathering tools but they must also be able to spend the time necessary to interpret the large volumes of data generated by modern network monitoring devices. Although a degree of automated assistance is provided by existing intelligent decision support tools, it remains for the protection engineer to manually collate and interpret the output of each system in order to compile a comprehensive understanding of each disturbance. As detailed in this thesis, the requirement for manual intervention has been eliminated through the development of the Protection Engineering Diagnostic Agents (PEDA) decision support architecture capable of automating all aspects of post-fault disturbance analysis. An essential component within this architecture is an alarm processor developed specifically to assist protection engineers with the early stages of post-fault disturbance analysis. The novel reasoning methodology employed emulates a protection engineer's approach to alarm analysis, providing automatic identification of transmission system disturbances and events. PEDA achieves fully automated post-fault disturbance analysis through the novel use of Multi-Agent Systems (MAS) to integrate the alarm processor with other automated systems for fault record retrieval, fault record interpretation and protection validation. As will be described in the thesis, achieving systems integration using MAS provides for levels of architecture flexibility and extensibility not previously realised within existing integrated decision support architectures. The PEDA architecture was developed following a comprehensive eleven stage methodology created as part of the reported research to assist with the specification of MAS for decision support within the power industry. Each stage of the PEDA specification process is detailed together with its implementation. Finally, the implemented architecture has been shown to offer automated retrieval, interpretation, collation and archiving of disturbance information within five minutes of a disturbance occurring. The beneficiaries of this near real-time provision of disturbance information need not be limited to protection engineers.

Cette thèse concerne l’étude des débats argumentatifs entre plusieurs agents artificiels. Notre travail est motivé par les difficultés qui surgissent quand un nombre important d’utilisateurs interagissent et débattent sur le Web, en échangeant des arguments sur différents sujets. Ces difficultés se situent au niveau de la représentation des connaissances des agents impliqués dans le débat, de la représentation du débat, de la façon de tirer les conclusions du débat, de l'évaluation de la qualité du débat, de la définition des protocoles spécifiques d'interaction, et de l'étude des stratégies des agents qui souhaitent atteindre un but précis via le débat. La contribution de cette thèse consiste donc en: a) la modélisation d'un débat argumentatif entre plusieurs agents, la modélisation des expertises de ces derniers, et l'agrégation des opinions des différents experts sur différentes parties d'un débat; b) l'apport d'une aide à l'agent responsable de la gestion d'un débat donné, la proposition d'une méthode permettant d'évaluer la qualité des débats argumentatifs en fonction de la confiance que l'on peut avoir en leurs conclusions, ainsi que la proposition de solutions permettant d'améliorer la qualité des débats dont les conclusions ne sont pas clairement établies; c) l'apport d'une aide permettant aux agents qui participent à un débat argumentatif de déterminer quels arguments placer dans le débat, l'étude des systèmes argumentatifs munis d'une structure dynamique, l'étude des moyens disponibles permettant à un agent d'influencer un système dynamique afin d'atteindre son but, l'étude des modifications minimales permettant à un agent d’atteindre un objectif donné, l'étude des stratégies argumentatives basées sur ce changement minimal; d) la définition, l'étude et l'évaluation des protocoles argumentatifs multi-agents, ainsi que la définition de protocoles de différents types (1) basés sur une évaluation numérique d'arguments et (2) basés sur des extensions d'arguments, l'utilisation des différentes techniques pour assurer la cohérence d'un débat tout en laissant une liberté d'expression aux agents, et enfin un grand nombre d'expérimentations (sur des débats) permettant de tester différentes stratégies et de les évaluer en fonction de différents critères
In this thesis multi-agent argumentation debates are studied. Our work is motivated by the issues which are raised when a large number of users interact and debate on the Web, by exchanging arguments on various topics. These issues are raised on the levels of representing the debating users' knowledge, representing the debate, computing the debate's conclusions, evaluating the debate's quality, defining specific protocols for user interaction, and studying debate strategies which users employ in order to achieve particular goals. This thesis' contribution consists in: a) proposing a way to model a multi-agent argumentation debate where the participants have different types of expertise, and proposing a way to aggregate their opinions; b) offering support to the agent who is arbitrating a debate, proposing a way to evaluate the quality of a debate on the basis of how confident we can be on its conclusions, and proposing solutions for improving the quality of a debate which lacks definite conclusions; c) offering support to the debating agents in order to determine which arguments they should put forward, studying dynamic argumentation systems, studying the potential ways in which an agent can influence a dynamic argumentation system in order to achieve his goal, studying the minimal change allowing an agent to achieve his goal, studying several argumentation strategies based on minimal change; d) defining, studying and evaluating multi-agent argumentation protocols, defining protocols of different types (1) based on numerical argument evaluation and (2) based on argument extensions, using different techniques to ensure a debate's coherence while ensuring some liberty of expression to the agents, and finally performing an important number of experiments (on debates) in order to test various strategies and evaluate them with respect to specific criteria

Cette thèse concerne l’étude des débats argumentatifs entre plusieurs agents artificiels. Notre travail est motivé par les difficultés qui surgissent quand un nombre important d’utilisateurs interagissent et débattent sur le Web, en échangeant des arguments sur différents sujets. Ces difficultés se situent au niveau de la représentation des connaissances des agents impliqués dans le débat, de la représentation du débat, de la façon de tirer les conclusions du débat, de l'évaluation de la qualité du débat, de la définition des protocoles spécifiques d'interaction, et de l'étude des stratégies des agents qui souhaitent atteindre un but précis via le débat. La contribution de cette thèse consiste donc en: a) la modélisation d'un débat argumentatif entre plusieurs agents, la modélisation des expertises de ces derniers, et l'agrégation des opinions des différents experts sur différentes parties d'un débat; b) l'apport d'une aide à l'agent responsable de la gestion d'un débat donné, la proposition d'une méthode permettant d'évaluer la qualité des débats argumentatifs en fonction de la confiance que l'on peut avoir en leurs conclusions, ainsi que la proposition de solutions permettant d'améliorer la qualité des débats dont les conclusions ne sont pas clairement établies; c) l'apport d'une aide permettant aux agents qui participent à un débat argumentatif de déterminer quels arguments placer dans le débat, l'étude des systèmes argumentatifs munis d'une structure dynamique, l'étude des moyens disponibles permettant à un agent d'influencer un système dynamique afin d'atteindre son but, l'étude des modifications minimales permettant à un agent d’atteindre un objectif donné, l'étude des stratégies argumentatives basées sur ce changement minimal; d) la définition, l'étude et l'évaluation des protocoles argumentatifs multi-agents, ainsi que la définition de protocoles de différents types (1) basés sur une évaluation numérique d'arguments et (2) basés sur des extensions d'arguments, l'utilisation des différentes techniques pour assurer la cohérence d'un débat tout en laissant une liberté d'expression aux agents, et enfin un grand nombre d'expérimentations (sur des débats) permettant de tester différentes stratégies et de les évaluer en fonction de différents critères
In this thesis multi-agent argumentation debates are studied. Our work is motivated by the issues which are raised when a large number of users interact and debate on the Web, by exchanging arguments on various topics. These issues are raised on the levels of representing the debating users' knowledge, representing the debate, computing the debate's conclusions, evaluating the debate's quality, defining specific protocols for user interaction, and studying debate strategies which users employ in order to achieve particular goals. This thesis' contribution consists in: a) proposing a way to model a multi-agent argumentation debate where the participants have different types of expertise, and proposing a way to aggregate their opinions; b) offering support to the agent who is arbitrating a debate, proposing a way to evaluate the quality of a debate on the basis of how confident we can be on its conclusions, and proposing solutions for improving the quality of a debate which lacks definite conclusions; c) offering support to the debating agents in order to determine which arguments they should put forward, studying dynamic argumentation systems, studying the potential ways in which an agent can influence a dynamic argumentation system in order to achieve his goal, studying the minimal change allowing an agent to achieve his goal, studying several argumentation strategies based on minimal change; d) defining, studying and evaluating multi-agent argumentation protocols, defining protocols of different types (1) based on numerical argument evaluation and (2) based on argument extensions, using different techniques to ensure a debate's coherence while ensuring some liberty of expression to the agents, and finally performing an important number of experiments (on debates) in order to test various strategies and evaluate them with respect to specific criteria

Doctor of Philosophy
Electrical and Computer Engineering
Balasubramaniam Natarajan
A cyber-physical system (CPS) typically consists of networked computational elements that control physical processes. As an integral part of CPS, the widespread deployment of communicable sensors makes the task of monitoring and control quite challenging especially from the viewpoint of scalability and complexity. This research investigates two unique aspects of overcoming such barriers, making a CPS more robust against data explosion and network vulnerabilities. First, the correlated characteristics of high-resolution sensor data are exploited to significantly reduce the fused data volume. Specifically, spatial, temporal and spatiotemporal compressed sensing approaches are applied to sample the measurements in compressed form. Such aggregation can directly be used in centralized static state estimation even for a nonlinear system. This approach results in a remarkable reduction in communication overhead as well as memory/storage requirement. Secondly, an agent based architecture is proposed, where the communicable sensors (identified as agents) also perform local information processing. Based on the local and underdetermined observation space, each agent can monitor only a specific subset of global CPS states, necessitating neighborhood information exchange. In this framework, we propose an agent based static state estimation encompassing local consensus and least square solution. Necessary bounds for the consensus weights are obtained through the maximum eigenvalue based convergence analysis and are verified for a radial power distribution network. The agent based formulation is also applied for a linear dynamical system and the consensus approach is found to exhibit better and more robust performance compared to a diffusion filter. The agent based Kalman consensus filter (AKCF) is further investigated, when the agents can choose between measurements and/or consensus, allowing the economic allocation of sensing and communication tasks as well as the temporary omission of faulty agents. The filter stability is guaranteed by deriving necessary consensus bounds through Lyapunov stability analysis. The states dynamically estimated from AKCF can be used for state-feedback control in a model predictive fashion. The effect of lossy communication is investigated and critical bounds on the link failure rate and the degree of consensus that ensure stability of the agent based control are derived and verified via simulations.

Simulation has been used to model combat for a long time. Recently, it has been accepted that combat is a complex adaptive system (CAS). Multi-agent systems (MAS) are also considered as a powerful modelling and development environment to simulate combat. Agent-based distillations (ABD) - proposed by the US Marine Corp - are a type of MAS used mainly by the military for exploring large scenario spaces. ABDs that facilitated the analysis and understanding of combat include: ISAAC, EINSTein, MANA, CROCADILE and BactoWars. With new concepts such as networked forces, previous ABDs can implicitly simulate a networked force. However, the architectures of these systems limit the potential advantages gained from the use of networks. In this thesis, a novel network centric multi-agent architecture (NCMAA) is pro-posed, based purely on network theory and CAS. In NCMAA, each relationship and interaction is modelled as a network, with the entities or agents as the nodes. NCMAA offers the following advantages: 1. An explicit model of interactions/relationships: it facilitates the analysis of the role of interactions/relationships in simulations; 2. A mechanism to capture the interaction or influence between networks; 3. A formal real-time reasoning framework at the network level in ABDs: it interprets the emergent behaviours online. For a long time, it has been believed that it is hard in CAS to reason about emerging phenomena. In this thesis, I show that despite being almost impossible to reason about the behaviour of the system by looking at the components alone because of high nonlinearity, it is possible to reason about emerging phenomena by looking at the network level. This is undertaken through analysing network dynamics, where I provide an English-like reasoning log to explain the simulation. Two implementations of a new land-combat system called the Warfare Intelligent System for Dynamic Optimization of Missions (WISDOM) are presented. WISDOM-I is built based on the same principles as those in existing ABDs while WISDOM-II is built based on NCMAA. The unique features of WISDOM-II include: 1. A real-time network analysis toolbox: it captures patterns while interaction is evolving during the simulation; 2. Flexible C3 (command, control and communication) models; I 3. Integration of tactics with strategies: the tactical decisions are guided by the strategic planning; 4. A model of recovery: it allows users to study the role of recovery capability and resources; 5. Real-time visualization of all possible information: it allows users to intervene during the simulation to steer it differently in human-in-the-loop simulations. A comparison between the fitness landscapes of WISDOM-I and II reveals similarities and differences, which emphasise the importance and role of the networked architecture and the addition of strategic planning. Lastly but not least, WISDOM-II is used in an experiment with two setups, with and without strategic planning in different urban terrains. When the strategic planning was removed, conclusions were similar to traditional ABDs but were very different when the system ran with strategic planning. As such, I show that results obtained from traditional ABDs - where rational group planning is not considered - can be misleading. Finally, the thesis tests and demonstrates the role of communication in urban ter-rains. As future warfighting concepts tend to focus on asymmetric warfare in urban environments, it was vital to test the role of networked forces in these environments. I demonstrate that there is a phase transition in a number of situations where highly dense urban terrains may lead to similar outcomes as open terrains, while medium to light dense urban terrains have different dynamics

Les systèmes multi-agents sont des systèmes dynamiques composés par plusieurs éléments qui interagissent entre eux. Ces éléments sont appelés agents. Un agent est un système dynamique caractérisé par deux propriétés. La première est que les agents sont autonomes— c’est-à-dire qu’ils ne sont pas dirigés par l’environnement extérieur et ils peuvent évoluer selon un comportement auto-organisé. La seconde est que les agents sont capables de communiquer entre eux pour accomplir des tâches complexes, telles que la coopération, la coordination et la résolution de conflits. L’un des problèmes courants concernant les systèmes multi-agents est la synchronisation. Les agents sont synchronisés lorsque leur évolution dans le temps converge vers une trajectoire commune. Plusieurs applications du monde réel peuvent être conceptualisés comme des problèmes de synchronisation des systèmes multi-agents : par exemple, l’alignement en vitesse ( flocking en anglais), et le contrôle de la formation du mouvement de groupes cohérents. La synchronisation des systèmes multi-agents peut être obtenue grâce à différentes techniques de contrôle. Dans cette thèse nous proposons des méthodes de contrôle centralisées et distribuées pour la synchronisation des systèmes multi-agents. Nous développons des conditions nécessaires et suffisantes pour la synchronisation des systèmes multi-agents, composés par des agents identiques et linéaires qui ne changent pas dans le temps, en utilisant une approche Lyapunov. Ces conditions sont utilisées pour la conception de lois de contrôles distribuées. ensuite, nous étendons les résultats aux systèmes multi-agents soumis à des perturbations externes, assurant un niveau de performance désiré grâce à une technique de contrôle de type 퐻 ∞ . enfin, nous étendons l’analyse aux systèmes multi-agents avec contraintes sur les actionneurs, en utilisant des techniques de contrôle anti-windup. Nous évaluons l’efficacité et les performances des stratégies de contrôle proposées dans plusieurs simulations, dont deux d’entre elles sont inspirées par des applications issues du monde réel. La première est le contrôle du vol en formation d’avions, et la seconde est l’analyse de la transmission de contenus vidéo comme un problème de synchronisation. Nous comparons aussi les résultats obtenus avec des techniques de contrôle alternatives
Multi-agent systems are dynamical systems composed of multiple interacting elements known as agents . Each agent is a dynamical system with two characteristics. First, it is capable of autonomous action—that is, it is able to evolve according to a self-organised behavior, which is not influenced by the external environment. Second, it is able to exchange information with other agents in order to accomplish complex tasks, such as coordination, cooperation, and conflict resolution. One commonly studied problem in multi-agent systems is synchronization. The agents are synchronized when their time evolutions converge to a common trajectory. Many real-world applications, such as flocking and formation control, can be cast as synchronization problems. Agent synchronization can be achieved using different approaches. In this thesis, we propose distributed and centralized control paradigms for the synchronization of multi-agent systems. We develop necessary and sufficient conditions for the synchronization of multi-agent systems, composed by identical linear time-invariant agents, us- ing a Lyapunov-based approach. Then we use these conditions to design distributed synchronization controllers. Then, we extend this result to multi-agent systems subject to external disturbances enforcing disturbance rejection with 퐻 ∞ control techniques. Furthermore, we extend the analysis to multi-agent systems with actuator constraints using LMI-based anti-windup techniques. We test the proposed control design strategies in simulated examples among which two are inspired by real-world applications. In the first, we study airplane formation control as a synchronization problem. In the second, we analyze the delivery of video streams as a synchronization problem and we compare the results to existing controllers

Modern operating systems should be extensible and flexible. This means that the operating system should be able to accept new behaviour and change existing behaviour without too much trouble and that it should ideally also be able to do this without any, or very little, downtime. Furthermore, during the past years the importance of the network has increased drastically, creating a demand for operating systems to function in a distributed environment. To achieve this flexibility and distribut-edness, I have designed and evaluated ABOS, an Agent-Based Operating System. ABOS uses agents to solve all the tasks of the operating system kernel, thus moving away from traditional monolithic kernel structures. Early results show that I have gained in flexibility and modularity, creating a fault-tolerant distributed operating system that can adapt and be adapted to almost any situa-tion with negligible decrease in performance. Within ABOS some tasks has been designed further, and there exists a demonstration of how the agent-based filesystem might work.

In the context of emerging distribution system with large penetration of distributed generation and storage from prosumers, we consider the distribution system as a multi-layers interacting complex system. The complexity of the system, characterized by several interacting layers fit in the context of physical (network), cyber, social and natural environment, cannot be captured by closed form mathematical models and new approaches derived from complex sciences, as Multi Agent Simulation (MAS), will be employed for developing proper tools. Based on MAS, where individual arbitrariness and realities can be represented almost as in detail as designers want, complex decision making problems encountered in the emerging distribution system can be implemented, learned, and evaluated through predesigned MAS models; evolutions of complex multilayer system and interactions inside can be captured with utmost concretes. Future projections such as emerging distribution system can be simulated ex-ante; perplexities that may arouse can be diagnosed and even resolved in advance.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, December 2003.
Thesis advisor(s): James B. Michael, Mikhail Auguston. Includes bibliographical references (p. 52-54). Also available online.

A Distributed observer design is described for estimating the state of a continuous-time, input free, linear system. This thesis explains how to construct the local estimators, which comprise the observer inputs and outputs, and it is shown which are the requirements to deal with this structure. Every agent senses an output signal from the system and distributes it across a fixed-time network to its neighbors. The information flow increases the capability of each agent to estimate the state of the system and uses collaboration to improve the quality of data. The proposed solution has several positive features compared to recent results in the literature, which include milder assumptions on the network connectivity and the maximum dimension of the state of each observer does not exceed the order of the plant. The conditions are reduced to certain detectability requirements for each cluster of agents in the network, where a cluster is identified as a subset of agents that satisfy specific properties. Instead, the dimension of each observer is reduced to the number of possible observable states of the system, collected by the agent and by the neighbors.

Recent years have witnessed a surge in demand for infrastructure and services to cover high demands on processing big chunks of data and applications resulting in a mega Cloud Datacenter. A datacenter is of high complexity with increasing difficulties to identify, allocate efficiently and fast an appropriate host for the requested virtual machine (VM). Establishing a good awareness of all datacenter’s resources enables the allocation “placement” policies to make the best decision in reducing the time that is needed to allocate and create the VM(s) at the appropriate host(s). However, current algorithms and policies of placement “allocation” do not focus efficiently on awareness of the resources of the datacenter, and moreover, they are based on conventional static techniques. Which are adversely impacting on the allocation progress of the policies. This thesis proposes a new Agent-based allocation/placement policy that employs some of the Multi-Agent system features to get a good awareness of Cloud Datacenter resources and also provide an efficient allocation decision for the requested VMs. Specifically, (a) The Multi-Agent concept is used as a part of the placement policy (b) A Contract Net Protocol is devised to establish good awareness and (c) A verification process is developed to fully dimensional VM specifications during allocation. These new results show a reduction in response time of VM allocation and the usage improvement of occupied resources. The proposed Agent-based policy was implemented using the CloudSim toolkit and consequently was compared, based on a series of typical numerical experiments, with the toolkit’s default policy. The comparative study was carried out in terms of the time duration of VM allocation and other aspects such as the number of available VM types and the amount of occupied resources. Moreover, a two-stage comparative study was introduced through this thesis. Firstly, the proposed policy is compared with four state of the art algorithms, namely the Random algorithm and three one-dimensional Bin-Packing algorithms. Secondly, the three Bin-Packing algorithms were enhanced to have a two-dimensional verification structure and were compared against the proposed new algorithm of the Agent-based policy. Following a rigorous comparative study, it was shown that, through the typical numerical experiments of all stages, the proposed new Agent-based policy had superior performance in terms of the allocation times. Finally, avenues arising from this thesis are included.

L'eau, l'énergie et l’alimentation sont des ressources essentielles pour l’être humain, et sont nécessaires pour garantir le développement économique et atteindre les objectifs de développement durable. La demande mondiale de ces ressources augmente régulièrement en raison de la croissance démographique et du changement climatique. Par rapport à 2012, la dépendance à l'eau, l'énergie et l'alimentation devrait augmenter respectivement de 40, 50 et 35% d'ici à 2050. Il est prévu que l'atmosphère continue à se réchauffer au cours du XXIe siècle, ce qui exercera une pression croissante sur l'utilisation de l'énergie, la disponibilité de l'eau et la production alimentaire. Ces pressions peuvent entraîner des conflits, comme la compétition pour l’accès à des terres et des ressources contestées. Afin de garantir un accès sécuritaire à l'eau, l'énergie et l’alimentation pour le développement humain, les parties prenantes et les décideurs politiques doivent considérer les différentes vulnérabilités lors de l'élaboration de stratégies visant à réduire les risques climatiques. En outre, l'eau, l'énergie et l’alimentation sont étroitement liées et leurs chaînes d'approvisionnement présentent à la fois des synergies et des compromis. Le lien entre ces trois ressources et l'étude de leur interdépendance a été désigné dans la littérature sous le nom de "Water Energy Food Nexus'' (WEFN). Cette thèse explore les systèmes eau-énergie-alimentation abordés sous l'angle de la communauté Procédés et Systèmes Industriels (PSI), en s’intéressant aux interdépendances complexes de ces systèmes et les potentiels conflits le long de leur chaîne d'approvisionnement
Water, energy, and food are critical resources required to meet basic human needs, ensure economic development, and achieve sustainable development goals. Global demand for these resources is steadily rising due to population growth and climate change. Compared to their 2012 values, reliance on water, energy, and food is projected to increase respectively by 40, 50, and 35 percent by the year 2050. In addition, it is expected that the atmosphere will continue to warm up during the twenty-first century, putting even more pressure on energy use, water availability, and food production. These pressures can result in conflicts, for example, over disputed land and resources. To ensure safe access to water, energy, and food for human development, it is important for planners and policy makers to incorporate various vulnerabilities when designing strategies to reduce climate risks. Moreover, water, energy, and food are highly interrelated, presenting both synergisms and trade-offs along their supply chains. The connection of these three resources and the study of their interdependencies has been referred to in the literature as the Water Energy Food Nexus (WEFN). This dissertation explores the Water Energy Food Nexus, examining the intricate interdependencies and potential conflicts along their supply chain.Within the challenges present in WEFN systems, effective decision-making tools are indispensable. Process Systems Engineering (PSE) tools offer promising avenues for managing WEFN systems. This thesis conducts a thorough literature review, identifying gaps in existing optimization models for WEFN management. Subsequently, a generic multi-objective optimization model is formulated and applied to a real-case study at a regional scale, with sensitivity analyses revealing diverse scenarios. Recognizing the roles of various agents and actors within WEFN systems, a multi-agent analysis, coupled with a multi-criteria decision analysis is executed. The tools and methodologies developed in this study not only contribute to the PSE community, but also provide benchmarks for a comparative analysis of WEFN systems. This research emphasizes the vital role of PSE in addressing complexities of WEFN systems, offering insights for planners and policymakers dealing with the critical interdependencies of water, energy, and food resources

La place importante du tutorat dans la réussite d'un dispositif de formation en ligne a ouvert un nouvel axe de recherche dans le domaine des EIAH (Environnements Informatiques pour l'Apprentissage Humain). Nos travaux se situent plus particulièrement dans le champ de recherches des ACAO. Dans un contexte collaboratif, le tutorat et les outils « d'awareness » constituent des solutions admises pour faire face à l'isolement qui très souvent, mène à l'abandon de l'apprenant. Ainsi, du fait des difficultés rencontrées par le tuteur pour assurer un encadrement et un suivi appropriés à partir des traces de communication (en quantités conséquentes) laissées par les apprenants, nous proposons une approche multi-agents pour analyser les conversations textuelles asynchrones entre apprenants. Ces interactions sont révélatrices de comportements sociaux-animateur, indépendant, etc... qu'il nous paraît important de pouvoir repérer lors d'une pédagogie de projet pour permettre aux apprenants de situer leurs travaux par rapport aux autres apprenants et situer leur groupe par rapport aux autres groupes d'une part, et d'autre part permettre au tuteur d'accompagner les apprenants dans leur processus d'apprentissage, repérer et soutenir les individus en difficulté pour leur éviter l'abandon. Ces indicateurs seront déduits à partir des grands volumes d'échanges textuels entre apprenants.L'approche a été ensuite testée sur une situation réelle, qui a montré une parfaite concordance entre les résultatsobservés par des tuteurs humains et ceux déterminés automatiquement par notre système
The growing importance of online training has put emphasis on the role of remote tutoring. A whole new area of research, dedicated to environment for human learning (EHL), is emerging. We are concerned with this field. More specifically, we will focus on the monitoring of learners.The instrumentation and observation of learners activities by exploiting interaction traces in the EHL and the development of indicators can help tutors to monitor activities of learners and support them in their collaborative learning process. Indeed, in a learning situation, the teacher needs to observe the behavior of learners in order to build an idea about their involvement, preferences and learning styles so that he can adapt the proposed activities. As part of the automatic analysis of collaborative learner¿s activities, we describe a multi agent approach for supporting learning activities in a Virtual Learning Environment context. In order to assist teachers who monitor learning processes, viewed as a specific type of collaboration, the proposed system estimates a behavioral (sociological) profile for each student. This estimation is based on automatic analysis of students textual asynchronous conversations. The determined profiles are proposed to the teacher and may provide assistance toteacher during tutoring tasks. The system was experimented with students of the master "software quality" of the Ibn Tofail University. The results obtained show that the proposed approach is effective and gives satisfactory results

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.

Si definisce “smart home” una residenza equipaggiata con tecnologie per favorire il monitoraggio dei residenti, promuovere la loro indipendenza e aumentare la qualità della loro vita. In generale, le smart home controllano le operazioni all’interno dell’ambiente domestico e si adattano automaticamente alle esigenze degli abitanti. I sistemi di reasoning per smart home (“Smart Home Reasoning Systems” – SHRS) hanno il compito di regolare il controllo automatico esercitato dalle smart home e di implementarne l’adattabilità agli abitanti. Per questo, gli SHRS sono stati oggetto di un’ampia ricerca. Tuttavia, c’è ancora un’evidente mancanza di uno studio sistematico sulle caratteristiche e le specifiche di tali sistemi. Per colmare il gap, la prima parte di questa tesi esplora il dominio degli SHRS. Abbiamo pertanto applicato il metodo della “Systematic Literature Review” (SLR) fornendo un’analisi approfondita di 135 articoli scientifici, selezionati tra i risultati di una ricerca sia automatica che manuale condotta su sei database online. A partire dalla SLR, questa tesi mostra come il 43% delle smart home presentate in letteratura sono progettate per fornire servizi generici di domotica. La SLR presenta anche dodici requisiti principali e caratteristiche per gli SHRS. Inoltre, la SLR classifica il 55,5% dei contributi analizzati come teorici. Tra tutti i contributi, il 51,5% risulta basato su tecniche di intelligenza artificiale simbolica. In aggiunta, grazie alla SLR, questa tesi analizza come differenti tecniche di reasoning sono applicate nelle smart home, valutandone semplificazioni, punti di forza e limiti e identificandone le principali sfide in ambiente domestico. Infine, la SLR evidenzia l’importanza di sviluppare sistemi di reasoning ibridi e la necessità di gestire incertezza e inconsistenze all’interno degli SHRS. Incertezza e inconsistenze caratterizzano gli obiettivi e le attività dei vari abitanti, che possono essere in condizione di sovrapposizione, di contemporaneità e/o di conflitto. Infatti, la SLR identifica il reasoning in condizioni di incertezza come una delle maggiori sfide per gli SHRS. L’incertezza è inevitabile nelle smart home: per esempio, i sensori a disposizione potrebbero fornire dati inaccurati o incompleti al fine di preservare la privacy degli occupanti. Inoltre, la natura dinamica di un ambiente domestico, così come comandi vaghi da parte degli abitanti, possono risultare in informazioni ambigue, incomplete e/o inconsistenti, portando la smart home in una condizione di incertezza. A partire da queste considerazioni, la seconda parte della tesi affronta alcune delle sfide legate all’incertezza: in particolare, l’incertezza dovuta a comunicazioni e comandi vaghi da parte degli utenti e l’informazione incompleta nei contesti di “ambient intelligence”. A tale scopo, abbiamo proposto un’architettura basata su sistemi multi-agente e ragionamento probabilistico per la realizzazione di un sistema di reasoning in condizioni di incertezza all’interno delle smart home. L’architettura proposta si basa sulla definizione di sistema multi-agente e su tecniche di “probabilistic logic programming”. In questa parte della tesi mostriamo come le tecniche di ragionamento probabilistico permettono agli agenti del sistema di ragionare in condizioni di incertezza. Inoltre, analizziamo come gli agenti intelligenti potenziano i propri processi di “decision-making” scambiando tra loro informazioni su dati mancanti o variabili non osservabili grazie a protocolli di interazione standard. Al contempo, quando un agente non ha risorse computazionali sufficienti per completare il proprio processo di reasoning, può avvantaggiarsi dei protocolli di interazione per delegare il ragionamento agli altri agenti nel sistema. In generale, dimostriamo che la combinazione di tecnologie per i sistemi multi-agente e tecniche di probabilistic logic programming può contribuire a costruire un sistema di reasoning affidabile anche a fronte di comandi vaghi degli abitanti e di informazione incompleta in ambienti parzialmente osservabili. Nell’ultima parte della tesi abbiamo affrontato i problemi di inconsistenza all’interno degli SHRS basati su regole, identificandone cinque sorgenti principali, Nello specifico, definiamo, formalizziamo e dimostriamo come regole in conflitto, duplicate, sovrapposte, in auto-loop e circolari possono essere rilevate usando le “Satisfiability Modulo Theories” (SMT). Il metodo proposto è stato validato sperimentalmente usando come modello regole raccolte in smart home esistenti. I risultati sperimentali forniscono prove promettenti a sostegno dell’affidabilità e dell’efficacia della soluzione proposta. Inoltre, il metodo proposto in questa parte della tesi può avere diverse applicazioni. Per prima cosa, può essere usato per costruire uno strumento di verifica statico (offline) per i sistemi di reasoning basati su regole. In aggiunta, può essere integrato come un componente di validazione delle regole per un sistema di reasoning. Infine, con alcuni accorgimenti, il metodo proposto può essere usato per la verifica delle proprietà di consistenza di un sistema di reasoning in domini diversi dalle smart home.
A smart home is a residence equipped with technologies that facilitate monitoring of residents, promote independence and increase the quality of life. In general, smart homes control the operations of the home environment and automatically adapt it to its inhabitants’ needs. The smart home reasoning system (SHRS) is in charge of determining the automatic control and adaptation operations of the home system. Recently, there has been extensive research concerning different aspects of the SHRS. However, there is a clear lack of systematic investigation targeted at these systems. To close the gap, in the first part of this thesis we explore the SHRS domain. For this reason, we applied the systematic literature review (SLR) method by conducting automatic and manual searches on six electronic databases, and in-depth analysis of 135 articles from the literature. From the SLR, this thesis identifies that about 43% of smart homes are designed to provide general home automation services. It also presents twelve major requirements and features of the SHRS. In addition, the SLR finds out that 55.5% of the research contributions in SHRS domain are theoretical, and 51.5% of them are based on symbolic artificial intelligence techniques. Further, it characterizes the usage and application trends of different reasoning techniques in smart home domain, and evaluates the major assumptions, strengths, and limitations of the proposed systems in the literature. Additionally, it discusses the challenges of reasoning in smart home environments. Finally, it underlines the importance of utilizing hybrid reasoning approaches and the need to handle uncertainty and inconsistency issues of the SHRS, as well as overlapping, simultaneous and conflicting multiple inhabitants’ activities and goals in the smart home environment. The SLR identifies reasoning under uncertainty as one of the major challenges of SHRSs. Uncertainty is inevitable in smart home environments as sensors may read inaccurate data or due to the existence of unobserved variables for privacy reasons. Furthermore, the dynamic nature of the home environment and vague human communications may result in ambiguous, incomplete and inconsistent contextual information, which ultimately lead the smart home system into uncertainty. With this in mind, the second part of this thesis tackle some of the challenges of uncertainty, in particular, uncertainty due to vague human communication and missing information in ambient intelligence environments. For this, we proposed probabilistic multi-agent system architecture for reasoning under uncertainty in smart home environments. The proposed smart architecture is based on the notion of multi-agent systems (MAS) technologies and probabilistic logic programming techniques. Afterwards, we show how the probabilistic reasoning technique enables the agents to reason under uncertainty. Furthermore, we discuss how intelligent agents enhance their decision-making process by exchanging information about missing data or unobservable variables using agent interaction protocols. Besides, when an agent lacks the necessary computational resources to accomplish its reasoning tasks, we illustrate how it can take advantage of the interaction protocols and delegate the tasks for other agents in the system. In general, we demonstrate that the combination of MAS technologies and probabilistic logic programming can help in building a reasoning system, which is capable of performing well under vague inhabitant commands and missing information in a partially observable environment. In the final part of the thesis, we tackled inconsistency issues in SHRSs, by identifying five major sources of inconsistencies in rule-based SHRSs. Specifically, we define, formalize and demonstrate how conflicting, duplicate, overlapping, self-looping and circular rules in SHRSs can be detected using satisfiability modulo theories. The proposed method was validated empirically using rules collected from a real-world SHRS as a model. The experimental results provide compelling evidence for the reliability and effectiveness of the proposed solution. The method presented in this part of the thesis can have multiple applications. First, it can be used to build a static (off-line) rule-based reasoning system verification tool. Second, it can be integrated as a rule validation component of the reasoning system. Besides, with some adaptation, the method can be directly used to verify the consistency properties of reasoning systems in other domains.

This thesis presents new approach to the supervisory control of complex systems modelled as Multi-Agent (MA) products of finite deterministic automata.
First, the centralized supervisory control problem for the MA product is considered. This differs from the standard approach to supervisory control since (i) vector languages are under consideration and (ii) each supervisor can disable only one particular component of a vector event. The notion of MA controllability is introduced and is shown to essentially constitute a necessary and sufficient condition for the synthesis of an MA supervisor. In the case when a given vector language K fails to be MA controllable, an algorithm for finding the infimal MA controllable superlanguage of K is presented. It is also shown that there exists, with respect to the inclusion partial order, a maximal MA controllable sublanguage of K. The results constitute a natural extension of the central classical supervisory control results for scalar systems to the more general MA product system case.
Second, the controllability properties of component structures are investigated. It is proved that the property of MA controllability is preserved under iterative MA product construction. Moreover, it is proved that in this case the MA product of supervisors of subsystems ensures the desired behaviour of the MA product of specifications for the iterative MA product. Several examples illustrate that neither standard controllability nor the second property of MA controllability, so-called MAC2, are preserved under projection operation. However, a sufficient condition for the standard controllability of a component in terms of the original vector specification and the MA product is given. The equality of the vector specification projected on the set of some components of an original MA product and an MA product of the projections on the corresponding components is shown to be a necessary and sufficient condition for the projected specification having MAC2 property. Furthermore, a special class of specifications, namely, state trajectory specifications, for both scalar and vector automata is considered and conditions for the embedding of two specifications are presented.
Third, the notion of the Graph-Relation MA product is introduced. Through this construction, we modify the connection of supervisors and vector system under consideration, and prove that the property of MA controllably remains the necessary and sufficient condition for the existence of a solution to the supervisory control problem. Next, an initial investigation on the MA product under partial observation is presented. The notions of MA observability and MA co-observability are formulated and it is shown that they play a key role in the solution of decentralized supervisory control problems for the MA product. Furthermore, applications to hybrid systems are explored.
Finally, a line of further research on centralized and decentralized MA product is mapped out, as well as complexity studies and the generation of MA software.

As one of the major fields, Networked Multi-Agent Systems (NMAS), which deals with the study of how network architecture and interactions among network components influence global control goals, has received wide attention across science and engineering. A usual problem that appears in the coordination of NMAS is the consensus problem, i.e., given initial values (scalar or vector) of agents, establish conditions under which through local interactions and computations, the agents asymptotically achieve some kind of agreement, such as control of mobile vehicles, information processing in sensor networks and design of distributed algorithms. Researches have mainly focused on the analysis of NMAS consensus in the past; the interconnection topology and some consensus algorithms were given in advance and the relevant research objective was to verify whether the states of all agents converge to some common value. Agents with single integrator dynamics, double integrator dynamics or more complicated dynamics are the present research emphasis. In addition, most present research activities focus on theoretical study of consensus problems based on relatively simple simulation experiments, but such method will still be a key element of research in the future. Although it is more complicated to consider consensus problems for a team of agents with more complex nonlinear dynamics and even heterogenous dynamics, such kind of problems are very important. To the best of our knowledge, there are few effective. results on this topic. Usually, no common equilibrium for all agents exists even if each isolated agent has an equilibrium, but NMAS with non-identical agents may still exhibit some consensus behaviors which are far from being fully understood. Certain reasonable and satisfactory boundedness of state motion errors between different agents can be taken as useful consensus properties. This thesis focuses on the global consensus problems of NMAS consisting of identical or non-identical agent dynamics, and the proposed consensus property is formulated in terms of certain boundedness of state errors. Moreover, in particular circumstances, we still investigate their exact consensus conditions. Compared with many existing results, the thesis makes several significant contributions. Firstly, we generalize the related results for the case of identical agent dynamics to the case of non-identical agent dynamics and the proposed results cover the existing criteria of networks with identical agent dynamics as special cases. Secondly, we consider the communication delay among the agents, global consensus criteria are given based on solving a number of lower dimensional matrix inequalities and scalar inequalities, which generalize the criteria using the method of the master stability function for NMAS with identical agents. Finally, globally bounded consensus conditions for both delay-independent and delay-dependent conditions based on the Lyapunov-Krasovskii functional method are derived.

There is an increasing need for multi-agent systems to operate under decentralised control regimes that support openness (individual components can enter and leave at will) and enable components representing distinct stakeholders with different aims and objectives to interact effectively. To this end, this thesis explores issues associated with using techniques from Game Theory and Mechanism Design to organise and analyse such systems. In particular, emphasis is given to distributed mechanisms in which there is distributed allocation (no single centre determines the allocation of the resources or the tasks) and distributed information (agents require information privately known by other agents in order to determine their own valuation or cost). Such mechanisms are important because, in comparison to their centralised counterparts, they are robust to a single-point failure, the computational burden can be potentially shared amongst many agents, and there is a reduction in bottlenecks since not all communication need pass through a single point. As a result, distributed mechanisms are better suited to many types of multi-agent application. To provide a grounding for the mechanisms we develop, the thesis contains a running example of a multi-sensor network scenario. In these systems, distributed allocation mechanisms are desirable since they are robust and reduce bottlenecks in the communication system. Furthermore, we show that distributed information naturally arises by deriving an information-theoretic valuation function. This scenario also gives rise to two additional requirements that are addressed within this thesis: (i) constrained capacity, whereby suppliers can only provide a limited amount of goods or services at any given time and (ii) uncertainty in task completion, whereby sensors potentially fail after they have been assigned tasks. Specifically, we focus on the \ac{vcg} mechanisms and investigate ways of extending it so as to address the requirements that arise within distributed setting in general and sensor networks. In particular, we choose the VCG as our point of departure since it is a mechanism that is efficient, individually rational and incentive compatible. Unfortunately, it is brittle in the sense that it does not conserve these desirable properties when considering the requirements that we outlined above. Therefore, we develop novel mechanisms that do. In more detail, the first part of this thesis considers two distributed allocation mechanisms --- a simultaneous auction environment and \ac{cda}. In the former, bidders place sealed bids in a number of selling auctions which are concurrently offering items. This results in a distributed allocation whereby the winner at each auction is determined by the seller conducting it. For this case, we derive the optimal strategy of the bidders using a game-theoretic approach. In the \acs{cda}, buyers and sellers, respectively, submit bids and asks continuously and the market clears when a bid is higher than an ask; meaning that the allocation is again determined in a distributed way. Furthermore, CDAs are known to yield close to efficient allocations, under certain conditions, even when utilising very simple strategies. However, in our case, we need to modify their format in order to deal with the requirement of constrained capacity. In both of these mechanisms, we study the system's loss in efficiency that ensues from distributing the allocation and find that it is $\frac{1}{e}$ in the simultaneous auction case and upto $35 \%$ in the continuous double auction case. The second part of this thesis is concerned with designing mechanisms when agents have distributed information within the system. Such settings are more general than those more traditionally studied in that they encompass the fact that agents can potentially change their valuation or cost upon knowing a signal about the system (which they have not observed) that was hitherto unknown to them. Specifically, we first show that interdependent valuations arise naturally within a sensor network when we develop an information-theoretic valuation function. To account for this, we significantly extend the VCG mechanism in order to deal with these interdependent valuations. We then go on to develop a mechanism that can deal with uncertainty in task allocation. In both of these cases, our mechanisms are shown to be efficient, individually rational and incentive compatible. Moreover, their computational properties are studied and efficient algorithms are designed (based on linear and dynamic programming) in order to speed up the computation of the allocation problem which is generally $\mathcal{NP}$-hard.

A set of systems are considered where there are multiple agents simultaneously active within real-time a environment. These systems are termed SMART systems and are found in domains as diverse as office administration, process control and aviation. Such systems place particular demands on agents that are not present in non-SMART systems. Actions may be time constrained in two ways: i) an action appropriate at one time may not be appropriate at another; ii) the time available for a required action may approximate to the time in which an agent is able to perform that action. In order to be able to function in such environments agents, both human and computer, must be aware of time constraints and the actions necessary to ensure that they do not compromise system goals.

The main topic of this thesis is the study of the interaction of agents interconnected in a large-scale network. In the thesis, three complementary problems have been afforded: Analysis of Consensus Networks, Synthesis of Higher Order Consensus Networks, and Application of Synchronization algorithms
Questa tesi di dottorato e incentrata sullo studio dell'interazione di agenti interconnessi in rete. In questa tesi vengono affrontati tre problemi complementari l'un l'altro: Analisi di reti di consenso, Sintesi di reti di consenso di ordine superiore, e Applicazione di algoritmi di sincronizzazione

Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
Includes bibliographical references (leaves 43-45).
by Athicha Muthitacharoen.
S.B.and M.Eng.

In this thesis several results on two main topics are collected: the coordination of networked multi agents systems and the diffusion of innovation of social networks. The results are organized in two parts, each one related with one of the two main topics. The common aspect of all the presented problems is the following: all the system are represented by graphs. Two are the main contributions of the first part. • A formation control strategy, based on gossip, which leads a set of autonomous vehicles to converge to a desired spatial disposition in absence of a common reference frame. If the vehicles have common direction, we prove that the proposed algorithm is robust against noise on displacement measurement. • \item The formalization of the Heterogeneous Multi Vehicle Routing Problem, which can be described as follows: given an heterogeneous set of mobile robots, and a set of task to be served randomly displaced in a 2D environment, find the optimal task assignment to minimize the service cost. We firstly characterize the optimal centralized solution, and then we propose two distributed algorithms, based on gossip, which lead the system to a sub-optimal solutions and are significantly computationally more efficient than the optimal one. The contributions of the second part are the following. • We study how the innovation spreads in a Social Network according to the so called Linear Threshold Model, in which the innovation is incepted in the network starting from a seed set, and nodes adopt the innovation if the ratio of the neighbours that have already adopted it is greater than or equal a certain threshold value. We focus on the cohesive subset of the network, which can be used to compute the set of final adopters. If a set is cohesive and none of the nodes have adopted the innovation at a certain time $t$, then they are not able to adopt the innovation at any $t'>t$. We propose an algorithm based on linear programming which computes the maximal cohesive subset of the complement of the seed set. • According to the Linear Threshold Model, we define two problem of interest in Social Networks analysis and characterize the optimal solution: the Influence Maximization Problem in Finite Time and the diffusion of innovation over a target set. • We characterize the novel Non Progressive Linear Threshold Model, which extends the classical Linear Threshold Model. We formalize the model and we give a characterization of the network dynamics in terms of cohesive and persistent sets

Considérant un point de vue général de cette thèse aborde le problème de trouver, à partir d'un ensemble de blocs de construction, un sous-ensemble qui procure une solution à un problème donné. Ceci est fait en tenant compte de la compatibilité de chacun des blocs de construction par rapport au problème et l'aptitude d'interaction entre ces parties pour former ensemble une solution. Dans la perspective notamment de la thèse sont les blocs de construction de méta-modèles et le problème donné est une description d'un problème peut être résolu en utilisant un logiciel et d'être résolu en utilisant un système multi-agents. Le noyau de la proposition de thèse est un processus qui analyse un problème donné et puis il proposé une solution possible basée sur système multi-agents pour ce problème. Il peut également indiquer que le problème ne peut être résolu par ce paradigme. Le processus adressée par la thèse consiste en les étapes principales suivantes: (1) A travers un processus de caractérisation on analyse la description du problème pour localiser le domaine de solutions, puis choisissez une liste de candidats des méta-modèles. (2) Les caractérisations de méta-modèles candidats sont prises, ils sont définis dans plusieurs domaines de la solution. On fait la chois parmi le domaine trouvé dans la étape précédant. (3) On crée un système multi-agents où chaque agent représente un candidat méta-modèle. Dans cette société les agents interagissent les uns avec les autres pour trouver un groupe de méta-modèles qui est adapté pour représenter une solution donnée. Les agents utilisent des critères appropriés pour chaque méta-modèle à représenter. Il évalue également la compatibilité des groupes créés pour résoudre le problème de décider le groupe final qui est la meilleure solution. Cette thèse se concentre sur la fourniture d'un processus et un outil prototype pour résoudre plutôt la dernière étape de la liste. Par conséquent, le chemin proposé a été créé à l'aide de plusieurs concepts de la méta-analyse, l'intelligence artificielle de coopération, de la cognition bayésienne, incertitude, la probabilité et statistique
From a general point of view this thesis addresses an automatic path to build a solution choosing a compatible set of building blocks to provide such a solution to solve a given problem. To create the solution it is considered the compatibility of each available building block with the problem and also the compatibility between each building block to be employed within a solution all together. In the particular perspective of this thesis the building blocks are meta-models and the given problem is a description of a problem that can be solved using software using a multi-agent system paradigm. The core of the thesis proposal is the creation of a process based on a multi-agent system itself. Such a process analyzes the given problem and the available meta-models then it matches both and thus it suggests one possible solution (based on meta-models) for the problem. Nevertheless if no solution is found it also indicates that the problem can not be solved through this paradigm using the available meta-models. The process addressed by the thesis consists of the following main steps: (1) Through a process of characterization the problem description is analyzed in order to locate the solution domain and therefore employ it to choose a list of most domain compatible meta-models as candidates. (2) There are required also meta-model characterization that evaluate each meta-model performance within each considered domain of solution. (3) The matching step is built over a multi-agent system where each agent represents a candidate meta-model. Within this multi-agent system each agent interact with each other in order to find a group of suitable meta-models to represent a solution. Each agent use as criteria the compatibility between their represented candidate meta-model with the other represented meta-models. When a group is found the overall compatibility with the given problem is evaluated. Finally each agent has a solution group. Then these groups are compared between them in order to find the most suitable to solve the problem and then to decide the final group. This thesis focuses on providing a process and a prototype tool to solve the last step. Therefore the proposed path has been created using several concepts from meta-analysis, cooperative artificial intelligence, Bayesian cognition, uncertainty, probability and statistics

Cette thèse a pour objectif principal de développer un simulateur multi-agents pour concevoir un système d'aide à la maitrise des risques des activités de maintenance. Le but est d'explorer la complexité de la maintenance et de spécifier les interactions entre la fonction maintenance, l'analyse et l'évaluation des risques. Nous nous intéressons d’une part, à concevoir un modèle systémique permettant d’identifier et de modéliser un système industriel, à montrer les différentes interactions entre ses éléments, à analyser et évaluer les risques des activités de maintenance. Nous proposons la méthode MOSAR et le langage UML pour concevoir un modèle cognitif de référence. Ce modèle a servi de point de départ pour la conception d’une base de données à l’aide du langage SQL, qui est exploitée par le modèle Multi-Agents afin d’acquérir les informations nécessaires à son fonctionnement.D’autre part, nous développons une architecture d’un Système Multi-Agents qui a pour vocation d’anticiper les situations de défaillances et la prise de décisions à l’aide de la simulation du comportement du système étudié. Une comparaison entre les plateformes existantes dédiées aux Systèmes Multi-Agents est effectuée pour choisir la plateforme adéquate à notre problématique pour la réalisation de la simulation.Finalement, les modèles développés sont appliqués dans le cadre d’une chaîne logistique pour le chargement et le déchargement de GPL (Gaz de Pétrole Liquéfié). Un simulateur a été développé à l’aide de la plateforme AnyLogic dans le but d’étudier le comportement du système et de simuler les scénarios de défaillances choisis par l’industriel pour le calcul de la criticité à partir de trois paramètres (fréquence, gravité, détectabilité) et l’obtention d’un Tableau de Bord contenant un ensemble d’indicateurs de performance de la maintenance. Les modèles de simulation proposés permettent d’orienter les industries vers les bonnes décisions pour éviter les situations à risques pouvant déclencher des événements perturbateurs dommageables
The main objective of this thesis is to develop a multi-agent approach to designing a model to overcome risks of maintenance activities. The aim is to explore the maintenance complexity and to indicate the interactions between the maintenance function and the risk assessment.Firstly, we are interested in designing a systemic model to identify and model the industrial system, to show the different interactions between its elements, to analyze and to evaluate risks of maintenance activities. We propose the MOSAR method and the UML language to design a cognitive reference model. This model served as a starting point for designing a database using the SQL language, which is operated by Multi-Agent model to acquire the necessary information for its operation.On the other hand, we develop a framework of a multi-agent system that aims to anticipate failures scenarios and the decision-making by simulating the studied system behaviour. A comparison between the existing platforms dedicated to Multi-Agent Systems is performed to choose the appropriate platform for the simulation.Finally, the developed models are applied in the LPG supply chain (Liquefied Petroleum Gas). A simulator was developed using the AnyLogic platform in order to study the system behaviour and to simulate the failure scenarios chosen by the industry, for the calculation of the criticality from three parameters (Frequency, severity, detectability), and for obtaining a Dashboard containing a set of maintenance performance indicators. The proposed simulation models help to guide the industries toward good decisions to avoid risky situations that may trigger disruptive events damaging

Les sujets discutés dans cette thèses’inscrivent dans le cadre général des systèmesinterconnectés. Nous abordons les réseauxmulti-agent qui ont des tâches coopératives etnous proposons un nouveau protocole deconsensus qui comporte des retards et desagents anticipatifs. Nous étudions lesconditions pour lesquelles un réseau organiséconformément au protocole proposé atteint leconsensus. Nous dérivons également desrésultats théoriques valables pour une classeplus générale de systèmes. Ces résultatsconcernent le cas des racines multiples surl’axe des imaginaires, situation qui peutcorrespondre aux réseaux avec une topologiechangeante.Dans notre approche, nous discutonsséparément le cas des racines multiples àl’origine et racines multiples sur l’axe desimaginaires sauf l’origine. Un autre résultatimportant comporte un nouveau modèle pourun réseau génétique qui fonctionne comme unmultiplexeur. Ce circuit innovant utilise troisentrées pour commander deux signaux desortie. Nous effectuons une analyse destabilité pour le modèle proposé et nousdémontrons que son point d’équilibre estunique et stable. Pour valider ce réseaugénétique, nous étudions également le modèlestochastique dérivé du modèle déterministe
This thesis discusses diverse types ofinterconnected systems through networks. Weaddress networks of agents with cooperativetasks and propose a new consensus protocolwith delays and anticipatory agents. We studythe consensus reaching conditions for networksorganized under the proposed model.Moreover, we derive some theoretical results,which can apply to a more general class ofsystems, concerning stability issues when theconsidered system has multiple imaginaryroots. In terms of networks, this situation cancorrespond to the case of switching topologynetworks, when the network can even bedisconnected at some point.We separately discuss the case of zerocharacteristic roots, and roots laying on theimaginary axis, except the origin. Finally, wepropose a gene network model with afunctionality similar to a multiplexer circuit.Thus, we control two outputs with three inputsignals, and we carry out a stability analysis.We prove the uniqueness and the stability ofthe network steady states, and validate thecontinuous and deterministic model with astochastic model

[ES] Recientemente, hay una fuerte y creciente influencia de aplicaciones en línea en nuestro día a día. Más concretamente las redes sociales se cuentan entre las plataformas en línea más usadas, que permiten a usuarios comunicarse e interactuar desde diferentes partes del mundo todos los días. Dado que estas interacciones conllevan diferentes riesgos, y además los adolescentes tienen características que los hacen más vulnerables a ciertos riesgos, es deseable que el sistema pueda guiar a los usuarios cuando se encuentren interactuando en línea, para intentar mitigar la probabilidad de que caigan en uno de estos riesgos. Esto conduce a una experiencia en línea más segura y satisfactoria para usuarios de este tipo de plataformas. El interés en aplicaciones de inteligencia artificial capaces de realizar análisis de sentimientos ha crecido recientemente. Los usos de la detección automática de sentimiento de usuarios en plataformas en línea son variados y útiles. Se pueden usar polaridades de sentimiento para realizar minería de opiniones en personas o productos, y así descubrir las inclinaciones y opiniones de usuarios acerca de ciertos productos (o ciertas características de ellos), para ayudar en campañas de marketing, y también opiniones acerca de personas como políticos, para descubrir la intención de voto en un periodo electoral, por ejemplo. En esta tesis, se presenta un Sistema Multi-Agente (SMA), el cual integra agentes que realizan diferentes análisis de sentimientos y de estrés usando texto y dinámicas de escritura (usando análisis unimodal y multimodal), y utiliza la respuesta de los analizadores para generar retroalimentación para los usuarios y potencialmente evitar que caigan en riesgos y difundan comentarios en plataformas sociales en línea que pudieran difundir polaridades de sentimiento negativas o niveles altos de estrés. El SMA implementa un análisis en paralelo de diferentes tipos de datos y generación de retroalimentación a través del uso de dos mecanismos diferentes. El primer mecanismo se trata de un agente que realiza generación de retroalimentación y guiado de usuarios basándose en un conjunto de reglas y la salida de los analizadores. El segundo mecanismo es un módulo de Razonamiento Basado en Casos (CBR) que usa no solo la salida de los analizadores en los mensajes del usuario interactuando para predecir si su interacción puede generar una futura repercusión negativa, sino también información de contexto de interacciones de usuarios como son los tópicos sobre los que hablan o información sobre predicciones previas en mensajes escritos por la gente que conforma la audiencia del usuario. Se han llevado a cabo experimentos con datos de una red social privada generada en laboratorio con gente real usando el sistema en tiempo real, y también con datos de Twitter.com para descubrir cuál es la eficacia de los diferentes analizadores implementados y del módulo CBR al detectar estados del usuario que se propagan más en la red social. Esto conlleva descubrir cuál de las técnicas puede prevenir mejor riesgos potenciales que los usuarios pueden sufrir cuando interactúan, y en qué casos. Se han encontrado diferencias estadísticamente significativas y la versión final del SMA incorpora los analizadores que mejores resultados obtuvieron, un agente asesor o guía basado en reglas y un módulo CBR. El trabajo de esta tesis pretende ayudar a futuros desarrolladores de sistemas inteligentes a crear sistemas que puedan detectar el estado de los usuarios interactuando en sitios en línea y prevenir riesgos que los usuarios pudiesen enfrentar. Esto propiciaría una experiencia de usuario más segura y satisfactoria.
[CA] Recentment, hi ha una forta i creixent influència d'aplicacions en línia en el nostre dia a dia, i concretament les xarxes socials es compten entre les plataformes en línia més utilitzades, que permeten a usuaris comunicar-se i interactuar des de diferents parts del món cada dia. Donat que aquestes interaccions comporten diferents riscos, i a més els adolescents tenen característiques que els fan més vulnerables a certs riscos, seria desitjable que el sistema poguera guiar als usuaris mentre es troben interactuant en línia, per així poder mitigar la probabilitat de caure en un d'aquests riscos. Açò comporta una experiència en línia més segura i satisfactòria per a usuaris d'aquest tipus de plataformes. L'interés en aplicacions d'intel·ligència artificial capaces de realitzar anàlisi de sentiments ha crescut recentment. Els usos de la detecció automàtica de sentiments en usuaris en plataformes en línia són variats i útils. Es poden utilitzar polaritats de sentiment per a realitzar mineria d'opinions en persones o productes, i així descobrir les inclinacions i opinions d'usuaris sobre certs productes (o certes característiques d'ells), per a ajudar en campanyes de màrqueting, i també opinions sobre persones com polítics, per a descobrir la intenció de vot en un període electoral, per exemple. En aquesta tesi, es presenta un Sistema Multi-Agent (SMA), que integra agents que implementen diferents anàlisis de sentiments i d'estrés utilitzant text i dinàmica d'escriptura (utilitzant anàlisi unimodal i multimodal), i utilitza la resposta dels analitzadors per a generar retroalimentació per als usuaris i potencialment evitar que caiguen en riscos i difonguen comentaris en plataformes socials en línia que pogueren difondre polaritats de sentiment negatives o nivells alts d'estrés. El SMA implementa una anàlisi en paral·lel de diferents tipus de dades i generació de retroalimentació a través de l'ús de dos mecanismes diferents. El primer mecanisme es tracta d'un agent que realitza generació de retroalimentació i guia d'usuaris basant-se en un conjunt de regles i l'eixida dels analitzadors. El segon mecanisme és un mòdul de Raonament Basat en Casos (CBR) que utilitza no solament l'eixida dels analitzadors en els missatges de l'usuari per a predir si la seua interacció pot generar una futura repercussió negativa, sinó també informació de context d'interaccions d'usuaris, com són els tòpics sobre els quals es parla o informació sobre prediccions prèvies en missatges escrits per la gent que forma part de l'audiència de l'usuari. S'han realitzat experiments amb dades d'una xarxa social privada generada al laboratori amb gent real utilitzant el sistema implementat en temps real, i també amb dades de Twitter.com per a descobrir quina és l'eficàcia dels diferents analitzadors implementats i del mòdul CBR en detectar estats de l'usuari que es propaguen més a la xarxa social. Açò comporta descobrir quina de les tècniques millor pot prevenir riscos potencials que els usuaris poden sofrir quan interactuen, i en quins casos. S'han trobat diferències estadísticament significatives i la versió final del SMA incorpora els analitzadors que millors resultats obtingueren, un agent assessor o guia basat en regles i un mòdul CBR. El treball d'aquesta tesi pretén ajudar a futurs dissenyadors de sistemes intel·ligents a crear sistemes que puguen detectar l'estat dels usuaris interactuant en llocs en línia i prevenir riscos que els usuaris poguessen enfrontar. Açò propiciaria una experiència d'usuari més segura i satisfactòria.
[EN] In the present days, there is a strong and growing influence of on-line applications in our daily lives, and concretely Social Network Sites (SNSs) are one of the most used on-line social platforms that allow users to communicate and interact from different parts of the world every day. Since this interaction poses several risks, and also teenagers have characteristics that make them more vulnerable to certain risks, it is desirable that the system could be able to guide users when interacting on-line, to try and mitigate the probability of incurring one of those risks. This would in the end lead to a more satisfactory and safe experience for the users of such on-line platforms. Recently, interest in artificial intelligence applications being able to perform sentiment analysis has risen. The uses of detecting the sentiment of users in on-line platforms or sites are variated and rewarding. Sentiment polarities can be used to perform opinion mining on people or products, and discover the inclinations and opinions of users on certain products (or certain features of them) to help marketing campaigns, and also on people such as politics, to discover the voting intention for example in electoral periods. In this thesis, a Multi-Agent System (MAS) is presented, which integrates agents that perform different sentiment and stress analyses using text and keystroke dynamics data (using both unimodal and multi-modal analysis). The MAS uses the output of the analyzers for generating feedback for users and potentially avoids them from incurring risks and spreading comments in on-line social platforms that could lead to the spread of negative sentiment or high-stress levels. Moreover, the MAS incorporates parallelized analyses of different data types and feedback generation via the use of two different mechanisms. On the one hand, a rule-based advisor agent has been implemented, that generates feedback or guiding for users based on the output of the analyzers and a set of rules. On the other hand, a Case-Based Reasoning (CBR) module that uses not only the output of the different analyzers on the messages of the user interacting, but also context information from user interactions such as the topics being talked about or information about the previous states detected on messages written by people in the audience of the user. Experiments with data from a private SNS generated in a laboratory with real people using the system in real-time, and also with data from Twitter.com have been performed to ascertain the efficacy of the different analyzers implemented and the CBR module on detecting states of the user that propagate more in the network, which leads to discovering which of the techniques is able to better prevent potential risks that users could face when interacting, and in which cases. Significant differences were found and the final version of the MAS incorporates the best-performing analyzer agents, a rule-based advisor agent, and a CBR module. In the end, this thesis aims to help intelligent systems developers to build systems that are able to detect the state of users interacting in on-line sites and prevent risks that they could face, leading to a more satisfactory and safe user experience.
This thesis was funded by the following research projects: Privacy in Social Educational Environments during Child-hood and Adolescence (PESEDIA), Ministerio de Economia y Empresa (TIN2014-55206-R) and Intelligent Agents for Privacy Advice in Social Networks (AI4PRI), Ministerio de Economia y Empresa (TIN2017-89156-R)
Aguado Sarrió, G. (2021). MAS-based affective state analysis for user guiding in on-line social environments [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/164902
TESIS

Diagnostic techniques in model-based fault detection and isolation approaches are often based on residuals. If the residuals become greater than a certain threshold then an alarm can be triggered. However, disturbances, such as those caused by model uncertainty, affect the behavior of the residuals and therefore the performance of the diagnostic system. Fault detection becomes a matter of security when applied in multi-agent systems, since their distributed nature offers adversaries possibilities to attack the system. This thesis considers disturbances caused by model uncertainty which is often encountered during implementation. Their influence on a model-based fault detection and isolation scheme in multi-agent systems is analyzed and an evaluation technique for the residuals is proposed. Different attack scenarios are considered and their influence on the residuals will be discussed. Finally, experimental results circumstantiate the proposed approaches.

It is recognised that normative systems, and in particular electronic institutions and contracts are a potentially powerful means for making agent interactions in multi-agent systems effective and efficient. However, correctly specifying the behaviour of such systems is a difficult problem. Designers are faced with two concurrent, complex tasks: firstly they must specify the relationships (over time) between agents’ actions and their effects, and secondly they must also consider how agents’ actions are to be regulated through the definition of agents’ permissions and obligations. Such systems are typi- cally complex, and given this complexity it may be difficult for a designer to determine whether their original objectives have been captured by the specification of the system. In this dissertation we seek to address some of the problems associated with institu- tional specification. In order to do this we present a model for specifying institutions based on the notion of socially constructed reality that accounts not only for how the action and events which constitute the institution are described, but also how they are regulated. Institutions may be used in a number of ways, and may account for concepts at varying levels of abstraction. Recognising this we also investigate how several insti- tutions, each accounting for a particular aspect of a society may be composed and how the relationships between these institutions may be expressed. Given this model, we then demonstrate how, using the answer set programming paradigm institutional spec- ifications based on our model may be checked for the absence or presence of certain (un)desirable properties.

Environmentally conscious construction has received a significant amount of research attention during the last decades. Even though construction literature is rich in studies that emphasize the importance of environmental impact during the construction phase, most of the previous studies failed to combine environmental analysis with other project performance criteria in construction. This is mainly because most of the studies have overlooked the multi-objective nature of construction projects. In order to achieve environmentally conscious construction, multi-objectives and their relationships need to be successfully analyzed in the complex construction environment. The complex construction system is composed of changing project conditions that have an impact on the relationship between time, cost and environmental impact (TCEI) of construction operations. Yet, this impact is still unknown by construction professionals. Studying this impact is vital to fulfill multiple project objectives and achieve environmentally conscious construction. This research proposes an analytical framework to analyze the impact of changing project conditions on the relationship of TCEI. This study includes green house gas (GHG) emissions as an environmental impact category. The methodology utilizes multi-agent systems, multi-objective optimization, analytical network process, and system dynamics tools to study the relationships of TCEI and support decision-making under the influence of project conditions. Life cycle assessment (LCA) is applied to the evaluation of environmental impact in terms of GHG. The mixed method approach allowed for the collection and analysis of qualitative and quantitative data. Structured interviews of professionals in the highway construction field were conducted to gain their perspectives in decision-making under the influence of certain project conditions, while the quantitative data were collected from the Florida Department of Transportation (FDOT) for highway resurfacing projects. The data collected were used to test the framework. The framework yielded statistically significant results in simulating project conditions and optimizing TCEI. The results showed that the change in project conditions had a significant impact on the TCEI optimal solutions. The correlation between TCEI suggested that they affected each other positively, but in different strengths. The findings of the study will assist contractors to visualize the impact of their decision on the relationship of TCEI.

L’objectif de cette thèse est de fournir des modèles de référence, les méthodes de soutien et des outils qui simulent les change propagations dans un projet de développement de produit (PD) pour aider les prises de décision. Nous établissons d’abord un cadre d’analyse des changes de modéliser le contexte du change apparition et la propagation en prenant en compte les multiples domaines du projet PD simultané- ment. Dans le cadre, nous proposons les modèles conceptuels de change apparition et la propagation qui fournissent une méthode pour identifier les change et propagation et impliquent certaines caractéristiques du change propagations. S’appuyant sur cela, nous vous proposons les procédures de mise en place des réseaux de propagation. Au sein du réseau, nous proposons la méthodologie de simulation de l’évolution propaga- tions, puis de présenter le processus de mise en uvre des méthodologies et des modèles comme un prototype en utilisant la technologie à base multi-agents
The overall goal of this Ph.D. research is to provide reference models, support me- thods and tools that simulate change propagations in a Product Development (PD) project to assist decision-makings. We firstly establish a change analysis framework of modeling the context of change occurrence and propagation by taking into account the multiple knowledge areas of PD project simultaneously. Under the framework, we propose the conceptual models of change occurrence and change propagation that pro- vide a qualitative method to identify change and change propagation and imply some characteristics of change propagations. Relying on that, we suggest the procedures of building up the change propagation networks. Within the network, we propose the methodology of simulating change propagations and then present the process of im- plementing the methodologies and the models as a software prototype by using multi- agent based technology

The impact of spatial characteristics on the dynamics of urban development is a topic of great interest in urban studies. The interaction between the residents and the spatial characteristics is of particular interest in the context of urban models where some of the most famous urban models have been based on the process of individual settlements in some specific parts of cities.This research investigates the dynamism of urban development modeled by Cellular Automata and Multi-Agent System. The urban development, in this study embraces urban renewal and residential mobility. It corresponds to the residential mobility of households, attracted by residential and centrality comfort; these comforts are crystallized in some areas and residences of Strasbourg. The diversity and quality of these comforts become criteria for residential choice in a way that the households seek for proximity to these comforts.The Cellular Automata in this study, models the spatial characteristics of urban spatial units and they are identified by some inherent attributes that are equal to the comfort in residences and urban areas. The Multi- Agent System represent a system in which the population of the city interact between them and between them and the city; the agents delegate the socio-professional classes of households. During the spatiotemporal change, the aspiration of households forms the socio-spatio-temporal development of the city.

Le travail présenté dans cette thèse concerne le développement d'un Framework pour les Systèmes Multi-Agents Holoniques. Ce type de système se compose de structures auto-similaires appelées holons. Un ensemble de holons peut être vu, selon le niveau d'observation, comme une entité unique ou comme un groupe de holons en interactions. Pour concevoir un framework générique et modulaire, nous utilisons une approche organisationnelle. Nous définissons les comportements des entités du framework en termes de rôles et d'interactions. Le framework met l'accent sur la modélisation et la représentation de trois aspects importants d'un SMA Holonique. Structure et Gestion d'un Holon : cette partie du framework prend en compte l'organisation des membres et la gestion du super-holon. Une organisation spécifique est proposée pour définir les statuts des membres vis-à-vis de leur super-holon. Interactions dépendantes du Problème : Pour réaliser les buts et les tâches du super-holon, les membres doivent interagir et coordonner leurs actions. Ces comportements, dépendants du problème, constituent les organisations internes. Notre framework offre aussi la possibilité de modéliser ces aspects. Dynamique : La dynamique est une caractéristique inhérente des SMA. Le framework considère également deux caractéristiques intrinsèques aux SMA holoniques : la Fusion (création et intégration dans le super-holon) et l'Auto-Organisation. Chaque organisation est modélisée en utilisant le modèle Rôle-Interaction-Organisation (RIO). Ce modèle offre une spécification formelle des rôles et permet la vérification et la validation des spécifications. Le framework a été formellement spécifié et cette formalisation, nous a permis de prouver d'importantes propriétés importantes sur l'auto-organisation du système. Nous proposons également une méthodologie pour l'analyse et la conception des systèmes complexes basée sur la notion de "Vues du Système". Chaque vue se consacre à un aspect particulier du système, et est représentée par une holarchie. Deux applications illustrent les concepts présentés dans ce travail. La première applique le framework au cas du Maillage Adaptatif pour le dimensionnement de réseaux radiomobiles. Cette application illustre le raffinement de la partie auto-organisation du framework et la spécification formelle d'un problème réel. La deuxième présente quant à elle, l'application des SMA holoniques pour la simulation d'un important site industriel. Plusieurs holarchies sont utilisées pour capturer les interactions entre les chaînes de production et le trafic routier interne au site. Pour implémenter ces concepts nous proposons un ensemble de modules basés sur la plateforme MadKit
The work presented in this PhD thesis is concerned with the development of a framework for Holonic MultiAgent Systems. This type of systems consists in self-similar structures called holons. A set of holons may be seen, depending on the level of observation, as a unique entity or as a group of holons in interaction. In order to conceive a generic and modular modeling framework, we use an organizational approach. We define then the behavior of the frame work entities in terms of roles and their interactions. The framework is concerned with the modeling and representation of three important aspects of a Holonic MAS. Holon Structure and Management : This part of the framework considers how the members organize and manage the super-holon. It offers a specific organization whose roles define the status of the member from the super-holon's point of view. Goal-Dependent Interactions : In order to achieve the goals/tasks of the super-holon, the members must interact and coordinate their actions. These goal-dependent behaviors are called Internal Organizations and our framework also offers means to model these aspects of the super-holons functioning. Dynamics : Dynamics are inherent characteristics of MAS. The framework considers in particular two of the most attractive characteristics of Holonic MAS: Merging (Creating and Joining a super-holon) and Self-Organization. Each organization is modeled using the Role-Interaction-Organization (RIO) Model. This model offers a formal specification of roles that enables the validation and verification of the model. We have formally specified the framework. Based on this formalization we were able to prove important properties concerning the self-organization of the system. We propose some guidelines based upon this framework for the analysis and design of Complex Systems. Two applications illustrate the concepts presented. The first uses the framework to the Adaptive Meshing Problem applied to the dimensioning of radiomobile networks. It illustrates the refinement of a self-organization module and formal specification. The second presents the use of holonic MAS for the simulation of an important industrial plant. Multiple holarchies are used to capture the interaction between the production and traffic inside the plant. In order to implement these concepts we propose a set of modules based on the MadKit platform

Over the past few years, mining data located in heterogeneous and geographically distributed sites have been designated as one of the key important issues. Loading distributed data into centralized location for mining interesting rules is not a good approach. This is because it violates common issues such as data privacy and it imposes network overheads. The situation becomes worse when the network has limited bandwidth which is the case in most of the real time systems. This has prompted the need for intelligent data analysis to discover the hidden information in these huge amounts of distributed databases. In this research, we present an incremental approach for building an efficient Multi-Agent based algorithm for mining real world databases in geographically distributed sites. First, we propose the Distributed Multi-Agent Association Rules algorithm (DMAAR) to minimize the all-to-all broadcasting between distributed sites. Analytical calculations show that DMAAR reduces the algorithm complexity and minimizes the message communication cost. The proposed Multi-Agent based algorithm complies with the Foundation for Intelligent Physical Agents (FIPA), which is considered as the global standards in communication between agents, thus, enabling the proposed algorithm agents to cooperate with other standard agents. Second, the BitTable Multi-Agent Association Rules algorithm (BMAAR) is proposed. BMAAR includes an efficient BitTable data structure which helps in compressing the database thus can easily fit into the memory of the local sites. It also includes two BitWise AND/OR operations for quick candidate itemsets generation and support counting. Moreover, the algorithm includes three transaction trimming techniques to reduce the size of the mined data. Third, we propose the Pruning Multi-Agent Association Rules algorithm (PMAAR) which includes three candidate itemsets pruning techniques for reducing the large number of generated candidate itemsets, consequently, reducing the total time for the mining process. The proposed PMAAR algorithm has been compared with existing Association Rules algorithms against different benchmark datasets and has proved to have better performance and execution time. Moreover, PMAAR has been implemented on real world distributed medical databases obtained from more than one hospital in Egypt to discover the hidden Association Rules in patients¿ records to demonstrate the merits and capabilities of the proposed model further. Medical data was anonymously obtained without the patients¿ personal details. The analysis helped to identify the existence or the absence of the disease based on minimum number of effective examinations and tests. Thus, the proposed algorithm can help in providing accurate medical decisions based on cost effective treatments, improving the medical service for the patients, reducing the real time response for the health system and improving the quality of clinical decision making.

Over the past few years, mining data located in heterogeneous and geographically distributed sites have been designated as one of the key important issues. Loading distributed data into centralized location for mining interesting rules is not a good approach. This is because it violates common issues such as data privacy and it imposes network overheads. The situation becomes worse when the network has limited bandwidth which is the case in most of the real time systems. This has prompted the need for intelligent data analysis to discover the hidden information in these huge amounts of distributed databases. In this research, we present an incremental approach for building an efficient Multi-Agent based algorithm for mining real world databases in geographically distributed sites. First, we propose the Distributed Multi-Agent Association Rules algorithm (DMAAR) to minimize the all-to-all broadcasting between distributed sites. Analytical calculations show that DMAAR reduces the algorithm complexity and minimizes the message communication cost. The proposed Multi-Agent based algorithm complies with the Foundation for Intelligent Physical Agents (FIPA), which is considered as the global standards in communication between agents, thus, enabling the proposed algorithm agents to cooperate with other standard agents. Second, the BitTable Multi-Agent Association Rules algorithm (BMAAR) is proposed. BMAAR includes an efficient BitTable data structure which helps in compressing the database thus can easily fit into the memory of the local sites. It also includes two BitWise AND/OR operations for quick candidate itemsets generation and support counting. Moreover, the algorithm includes three transaction trimming techniques to reduce the size of the mined data. Third, we propose the Pruning Multi-Agent Association Rules algorithm (PMAAR) which includes three candidate itemsets pruning techniques for reducing the large number of generated candidate itemsets, consequently, reducing the total time for the mining process. The proposed PMAAR algorithm has been compared with existing Association Rules algorithms against different benchmark datasets and has proved to have better performance and execution time. Moreover, PMAAR has been implemented on real world distributed medical databases obtained from more than one hospital in Egypt to discover the hidden Association Rules in patients' records to demonstrate the merits and capabilities of the proposed model further. Medical data was anonymously obtained without the patients' personal details. The analysis helped to identify the existence or the absence of the disease based on minimum number of effective examinations and tests. Thus, the proposed algorithm can help in providing accurate medical decisions based on cost effective treatments, improving the medical service for the patients, reducing the real time response for the health system and improving the quality of clinical decision making.

Une chaîne logistique est composée d’entreprises fabriquant et distribuant des produits aux consommateurs. En modélisant chacune de ses entreprises comme un agent intelligent, nous étudions l’effet « coup de fouet » qui s’y propage. Cet effet consiste en l’amplification de la variabilité des commandes passées par les entreprises lorsque l’on s’éloigne du client final. Dans un premier temps, nous modélisons chaque entreprise d’une chaîne logistique forestière québécoise comme un agent intelligent, afin de proposer deux mécanismes de coordination décentralisés réduisant ce phénomène. Des simulations de ce système multiagent montrent que ce mécanisme est efficace pour une chaîne logistique dans son ensemble. Dans un second temps, d’autres simulations sont utilisées pour construire un jeu, que nous analysons avec la Théorie de Jeux. Nous vérifions ainsi que les entreprises n’ont pas intérêt d’arrêter unilatéralement d’utiliser nos mécanismes de coordination (équilibre de Nash).
A supply chain is a set of companies that manufacture and distribute products to consumers. We study the “bullwhip effect” that is propagated therein by modelling each company as an intelligent agent. This effect is the amplification of the variability of orders placed by companies, as one moves away from end-customers. Firstly, we model each company in a Québec wood supply chain as an intelligent agent, in order to propose two decentralized coordination mechanisms reducing this phenomenon. Simulations of this multi-agent system show that our mechanism is efficient for a supply chain as a whole. Secondly, additional simulations are used to build a game, which we analyze with Game Theory. We verify here that companies have no incentive to cease unilaterally from using our two coordination mechanisms (Nash equilibrium).

Thesis (M.S. in Modeling, Virtual Environments and Simulation and M.S. in Computer Science)--Naval Postgraduate School, June 2003.
"This thesis is done in cooperation with the MOVES Institute"--Cover. Thesis advisor(s): Eugene Paulo, John Hiles. Includes bibliographical references (p. 49). Also available online.

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O desenvolvimento de soluções de Inteligência Artificial (IA) para sistemas computacionais é complexo dado a natureza dos problemas atacados, em particular quando envolvem problemas multiagentes e multitarefas (MAMT). Apesar de existirem vários métodos para o desenvolvimento de Sistema Multiagentes (SMA), são poucos os que dão alguma importância à compreensão do problema; e mesmo estes métodos não abordam os problemas MAMT com o devido detalhamento. Abordando a deficiência destas metodologias, estamos propondo o método Icelus que foca em guiar o analista em compreender e descrever corretamente o problema a ser solucionado. Icelus permitirá uma melhor abordagem na análise e compreensão de um problema MAMT, facilitando a distribuição do conhecimento para o restante do time de desenvolvimento, reduzindo o risco de erros de codificação ao longo do desenvolvimento do projeto.
The development of Artificial Intelligence (AI) to computational systems is a complex activity, given the nature of the problems attacked, in particular when they involve multi-agent problems and multitasking (MAMT). Although there are several methods for the development of Multi-agent System (MAS), there are just a few that give any importance to understanding the problem; and even these methods do not address the problems with all detailing that MAMT problems needs. Addressing the deficiency of these methods, we are proposing the Icelus method that focuses on leading the analyst to understand and describe correctly the problem to be solved. Icelus will enable a better approach in the analysis and understanding of a MAMT problem, facilitating the distribution of knowledge to the rest of the development team, reducing the risk of coding errors throughout the development of the project.

Transições sociotecnológicas são processos de modificação e substituição de regimes sociotecnológicos, estruturas sociais que englobam sistemas tecnológicos e produtivos, bem como políticas públicas, sistemas econômicos e significados simbólicos associados. A transição sociotecnológica tem sido discutida como um caminho para o desenvolvimento sustentável, dada a possibilidade de substituição de regimes sociotecnologicos vigentes por regimes que representem menores impactos sociais e ambientais. Apesar da atenção que a transição sustentável tem recebido em anos recentes, observa-se na literatura uma lacuna no estudo da função de agência na transição. O objetivo da presente pesquisa é analisar a agência no processo de transição sociotecnológica sustentável, e a principal contribuição está na proposição de um modelo conceitual estruturado para a explicação desta agência. No desenvolvimento do modelo adotou-se a perspectiva multinível, a qual estuda a transição a partir de três diferentes níveis de análise: nicho, regime e cenário. O modelo está consolidado em três ideias centrais, que se constituíram em hipóteses de trabalho no desenvolvimento da pesquisa. Propõe-se como primeira hipótese que a agência na transição seria distribuída, resultando de uma ação coletiva do nicho. Propõe-se também como segunda hipótese de trabalho que a agência seria exercida por meio da construção pelos atores nicho de um sistema de narrativas, o qual direcionaria as expectativas dos demais atores, bem como o compromisso resultante destas expectativas. Por fim, propõe-se como terceira hipótese que expectativas e compromisso seriam continuamente ajustados pelo desempenho do sistema, e a principal medida de desempenho na transição tecnológica estaria na capacidade do nicho em desenvolver aprendizado. Adotou-se no desenvolvimento da pesquisa uma abordagem multimétodo, a partir de um posicionamento epistemológico de complexidade organizacional; outra contribuição significativa de pesquisa está no tratamento metodológico adotado no teste do modelo proposto. O modelo conceitual proposto foi operacionalizado em uma fase de pesquisa qualitativa, a partir de em análise de conteúdo de narrativas socialmente construídas, e outra quantitativa, através de modelagem computacional por meio de um sistema multiagente. Para o desenvolvimento destas fases adotou-se como objeto de pesquisa o nicho de energia eólica brasileiro, o qual se entende como uma transição em andamento dado seu expressivo crescimento recente. Na fase qualitativa de pesquisa buscou-se caracterizar os processos discursivos envolvidos em transições tecnológicas sustentáveis. Observou-se que narrativas atuaram no estabelecimento de expectativas sobre nicho tecnológico, defendendo a existência de grande potencial de geração no Brasil, e a sustentabilidade da geração de energia eólica. A caracterização de narrativas resultado da fase qualitativa de pesquisa foi adotada na fase quantitativa de pesquisa como base para o desenvolvimento do processo de modelagem e simulação. O modelo computacional foi considerado como valido dada sua capacidade de representar o processo de constituição de um nicho tecnológico, e as três hipóteses de trabalho que consolidam o modelo conceitual proposto foram testadas por meio deste modelo. Os resultados de simulação observados dão suporte à aceitação das primeira e segunda hipóteses, embora indiquem pela rejeição da terceira. A principal implicação dos achados está na sugestão que a transição sustentável deve ser entendida como um processo iminentemente coletivo, não podendo ser conduzida de forma isolada por um único agente.
Socio-technological transitions are processes of change and replacement of socio-technical regimes, social structures that include technological and production systems, as well as the associated public policies, economic systems and symbolic meanings. Socio-technical transitions have been discussed as a path to sustainable development, due to the opportunity of replacement of incumbent socio-technical regimes by regimes that account for lesser social and environmental impacts. Despite the attention that sustainable transitions have recently received, it is observed in the literature a gap in the study of agency in the transition. The aim of this research is to analyze agency in the socio-technical transition to sustainability, and the main contribution is the proposition of a structured conceptual model in order to explain this agency. In developing the model, it was adopted the multi-level perspective, which studies the transition through three different levels of analysis: niche, regime and landscape. The model is consolidated in three core ideas, which constituted themselves in working hypotheses for the development of research. At first, it is proposed a first hypothesis the adoption of a conception of distributed agency, resulting from a collective action of the niche. It is also proposed as second work hypothesis that agency would be exerted through the construction by the social actors of the niche of a system of narratives, which would direct the expectations of other actors, as well as the commitment resulting from these expectations. Finally, it is proposed as the third work hypothesis that expectations and commitment would be continuously adjusted by system performance, and the main performance measure in the sociotechnical transition would be in the ability of the niche to develop learning. It was adopted in the research a multimethod design, from an epistemology of organizational complexity; another significant contribution of the research is the methodological approach adopted in testing the proposed model. The proposed conceptual model was operationalized in a qualitative research phase, using a content analysis of socially constructed narratives, and other quantitative phase, by means of computational modeling using a multi-agent system. To the development of these phases it was adopted as a research subject the Brazilian wind energy niche, which is understood as a transition in progress, given its significant recent growth. In qualitative research phase, we attempted to characterize the discursive processes involved in sustainable technological transitions. It was observed that narratives have acted in establishing expectations about technological niche, defending the existence of a large generation potential in Brazil, and the sustainability of wind power generation. The characterization of narratives resulting of the qualitative research phase was adopted in the quantitative phase as the basis for the development of modeling and simulation process. The computational model was considered valid, given its ability to represent the process of establishment of a technological niche. The three working hypotheses that consolidate the proposed conceptual model were tested using this model. The observed simulation results supported the acceptance of the first and second hypotheses, while indicating the rejection of the third one. The main implication of the findings is the suggestion that the transition to sustainability must be considered as a collective process, and cannot be conducted by a single individual agent.

Cette recherche se place dans le domaine de l’ingénierie industrielle, plus exactement aux premières étapes du processus d´innovation (Fuzzy Front-End). Aujourd´hui dans un monde globalisé, où la technologie est à la portée de tous, les entreprises cherchent de nouvelles techniques permettant de se distinguer de la concurrence, et offrent de nouveaux et meilleurs produits ou services ; une manière de conserver leurs avantages comparatifs ou d’en acquérir de nouveaux, pour des clients toujours plus exigeants, et dont les besoins changent constamment. Partant de ce constat, l’innovation se définit comme un processus long et continu, au sein duquel s’utilisent différents modèles. Du fait de la complexité du processus, il n’existe pas de modèle unique réunissant tous les besoins des clients. C’est pourquoi le processus d’innovation, implique différents acteurs de l’entreprise et de son environnement. Ces acteurs, dont l’importance varie, sont souvent d’origines diverses et possèdent des compétences variées. Ils ont des besoins différents, et sont soumis à des contraintes de travail différentes (ressources technologiques et financières, réglementations, etc...). Il paraît ainsi essentiel pour l’entreprise de créer un modèle unique, capable d’identifier les besoins de toutes les parties prenantes, avant d’entamer le processus de développement de nouveaux produits. C’est pour l’entreprise une manière de renforcer le processus d’innovation, et de réduire le taux d´échec lors du lancement de nouveaux produits. Ainsi l’objectif de cette étude est de proposer une nouvelle méthode d’analyse des impacts de l’innovation (A.I), afin de permettre aux entreprises d’identifier les besoins dynamiques des acteurs. Celles-ci pourront ainsi mieux définir leurs nouveaux produits et s’adapter plus facilement aux évolutions du marché. Cet outil fait partie d´une méthodologie de gestion des projets innovants, et doit être utilisé avant la définition des caractéristiques fonctionnelles du nouveau produit. Ceci nous ramène aux premières phases du développement, avant la conception du produit, qui comprennent toutes les étapes depuis la définition des besoins et opportunités pour l´innovation, jusqu’à la prise de décision pour le développement du nouveau produit, appelée Fuzzy Front-End. L’apport théorique de notre travail : Il n´existe pas de définition des impacts de l’innovation (I_n), nous avons donc fait un travail bibliographique sur le concept d’impact. Celui-ci a permis d’explorer les différentes définitions d´impact au sein de différentes disciplines (ingénierie, écologie, psychologie, etc.). Nous avons proposé de cette manière, notre propre définition de l’impact adaptée au contexte de l´innovation. Cette recherche bibliographique, nous a aussi permis d’identifier les différents types d´impacts et de justifier l´utilisation de différentes méthodologies. La contribution méthodologique : l’approche proposée pour l´analyse des impacts de l´innovation (A.I) se décompose en deux étapes. La première vise à modéliser l’« écosystème d´innovation », sur la base des relations, de l´importance et des besoins individuels de chacun des acteurs face au nouveau produit. Ceci grâce à une Analyse des Besoins Dynamiques (A.B.D), qui permettra d´obtenir les besoins agrégés permettant de représenter le système complet, sans considérer les possibles perturbations du milieu extérieur ou les impacts de la même innovation. Pour bien identifier et décrire les besoins des acteurs, nous avons basé la méthodologie sur l´observation de leurs activités. Ainsi, nous avons pu identifier les différents besoins des acteurs de l´innovation sur la base de l’analyse RAR (Ressources, Activités, Résultat), ensuite nous avons classifié les besoins grâce au modèle de KANO et ses améliorations réalisées par Tontini. Une méthode originale d’agrégation des besoins de tous les acteurs est proposée.[...]
This research belongs to the industrial engineering field, focusing on the first stages of the innovation process (Fuzzy Front-End). In a globalized world, where the technology is near to everyone, enterprises are looking for new technologies to be different from their competitors, offering new and better products / services as a strategy to keep or acquire new competitive advantages. Moreover, innovation is a large and continuous process, where different management models are used. But, because of the complexity of the process, no general model is suitable for situations and projects. Thus, the innovation process involves different stakeholders from the company and its environment. These individuals come from different origins (field of knowledge), have different needs, abilities, importance and work under different restrictions (technological or financial resources, work rules, etc.). Consequently, it is essential for the enterprise to identify all the needs of the parts involved in the products. And, a model is required in order to identify the stakeholder’s needs before starting design tasks. This model aims at more robustness in the new product development process and at the reduction of the failure rate when launching new products. Thus, the objective of this PhD thesis is to propose a new method to analyze the impact of the innovation, allowing companies to identify the dynamic actors' needs, to improve the definition of their new products and to adapt to the possible changes of the market. This tool is part of an innovative projects management methodology, used before the elaboration of the functional specifications of a new product. This locates the research in the first stages of development called Fuzzy Front-End: before the genesis of the product. Fuzzy front ends integrate among others the opportunity / needs identification for innovation to the development of the new product decision taking. The proposed approach for the innovation impact analysis (A.I) consists of two stages: the first one intends to model an innovation ecosystem, integrating the relations, the importance of each stakeholder and their individual necessities in regard to the new product. Through a Dynamic Needs Analysis (A.B.D) it will be possible to get the global needs, which represent the whole system, without considering the disturbances of the environment or the impact of the same innovation. Thus, the second stage of the model, through the generation of innovation impact scenarios (S.I.I), evaluates the impact of the innovation the new product may face at its market launching. Due to a new product emergence changes emerge: actors’ performance, their interrelations, the importance and their own needs about the product [...]

As humans, we tackle many problems in complex societies and manage the complexities of networked social systems. Cognition and sociability are two vital human capabilities that improve social life and complex social interactions. Adding these features to smart devices makes them capable of managing complex and networked Internet of Things (IoT) settings. Cognitive and social devices can improve their relationships and connections with other devices and people to better serve human needs. Nowadays, researchers are investigating two future generations of IoT: social IoT (SIoT) and cognitive IoT (CIoT). This study develops a new framework for IoT, called CSIoT, by using complexity science concepts and by integrating social and cognitive IoT concepts. This framework uses a new mechanism to leverage the friendships between devices to address service management, privacy, and security. The framework addresses network navigability, resilience, and heterogeneity between devices in IoT settings. This study uses a new simulation tool for evaluating the new CSIoT framework and evaluates the privacy-preserving ability of CSIoT using the new simulation tool. To address different CSIoT security and privacy issues, this study also proposes a blockchain-based CSIoT. The evaluation results show that CSIoT can effectively preserve the privacy and the blockchain-based CSIoT performs effectively in addressing different privacy and security issues.

This diploma thesis is focusing on description of processing social network analysis, design and implementation of a model that simulates a particular social network and its analysis. Social networks are modern and very used in this time. They are very good point for exploring. This project deal with static analysis social network, where social network is constructed by graph. We nd out di erent properties of single component and than we establish signi cance of them. Relationships between components are important too for us, because they have a big influence on propagation information in network. Structural properties figure out existence of di fferent communities. We simulate social network with multi-agent systems, they are desirable for represent changes in network. Multi-agent systems have implemented a simulation model that represents a particular social network. His behaviour was analyzed and examinated by chosen methods.

Simple games are a fundamental class of cooperative games. They have a huge relevance in several areas of computer science, social sciences and discrete applied mathematics. The algorithmic and computational complexity aspects of simple games have been gaining notoriety in the recent years. In this thesis we review different computational problems related to properties, parameters, and solution concepts of simple games. We consider different forms of representation of simple games, regular games and weighted games, and we analyze the computational complexity required to transform a game from one representation to another. We also analyze the complexity of several open problems under different forms of representation. In this scenario, we prove that the problem of deciding whether a simple game in minimal winning form is decisive (a problem that is associated to the duality problem of hypergraphs and monotone Boolean functions) can be solved in quasi-polynomial time, and that this problem can be polynomially reduced to the same problem but restricted to regular games in shift-minimal winning form. We also prove that the problem of deciding wheter a regular game is strong in shift-minimal winning form is coNP-complete. Further, for the width, one of the parameters of simple games, we prove that for simple games in minimal winning form it can be computed in polynomial time. Regardless of the form of representation, we also analyze counting and enumeration problems for several subfamilies of these games. We also introduce influence games, which are a new approach to study simple games based on a model of spread of influence in a social network, where influence spreads according to the linear threshold model. We show that influence games capture the whole class of simple games. Moreover, we study for influence games the complexity of the problems related to parameters, properties and solution concepts considered for simple games. We consider extremal cases with respect to demand of influence, and we show that, for these subfamilies, several problems become polynomial. We finish with some applications inspired on influence games. The first set of results concerns to the definition of collective choice models. For mediation systems, several of the problems of properties mentioned above are polynomial-time solvable. For influence systems, we prove that computing the satisfaction (a measure equivalent to the Rae index and similar to the Banzhaf value) is hard unless we consider some restrictions in the model. For OLFM systems, a generalization of OLF systems (van den Brink et al. 2011, 2012) we provide an axiomatization of satisfaction. The second set of results concerns to social network analysis. We define new centrality measures of social networks that we compare on real networks with some classical centrality measures.
Los juegos simples son una clase fundamental de juegos cooperativos, que tiene una enorme relevancia en diversas áreas de ciencias de la computación, ciencias sociales y matemáticas discretas aplicadas. En los últimos años, los distintos aspectos algorítmicos y de complejidad computacional de los juegos simples ha ido ganando notoriedad. En esta tesis revisamos los distintos problemas computacionales relacionados con propiedades, parámetros y conceptos de solución de juegos simples. Primero consideramos distintas formas de representación de juegos simples, juegos regulares y juegos de mayoría ponderada, y estudiamos la complejidad computacional requerida para transformar un juego desde una representación a otra. También analizamos la complejidad de varios problemas abiertos bajo diferentes formas de representación. En este sentido, demostramos que el problema de decidir si un juego simple en forma ganadora minimal es decisivo (un problema asociado al problema de dualidad de hipergrafos y funciones booleanas monótonas) puede resolverse en tiempo cuasi-polinomial, y que este problema puede reducirse polinomialmente al mismo problema pero restringido a juegos regulares en forma ganadora shift-minimal. También demostramos que el problema de decidir si un juego regular en forma ganadora shift-minimal es fuerte (strong) es coNP-completo. Adicionalmente, para juegos simples en forma ganadora minimal demostramos que el parámetro de anchura (width) puede computarse en tiempo polinomial. Independientemente de la forma de representación, también estudiamos problemas de enumeración y conteo para varias subfamilias de juegos simples. Luego introducimos los juegos de influencia, un nuevo enfoque para estudiar juegos simples basado en un modelo de dispersión de influencia en redes sociales, donde la influencia se dispersa de acuerdo con el modelo de umbral lineal (linear threshold model). Demostramos que los juegos de influencia abarcan la totalidad de la clase de los juegos simples. Para estos juegos también estudiamos la complejidad de los problemas relacionados con parámetros, propiedades y conceptos de solución considerados para los juegos simples. Además consideramos casos extremos con respecto a la demanda de influencia, y probamos que para ciertas subfamilias, varios de estos problemas se vuelven polinomiales. Finalmente estudiamos algunas aplicaciones inspiradas en los juegos de influencia. El primer conjunto de estos resultados tiene que ver con la definición de modelos de decisión colectiva. Para sistemas de mediación, varios de los problemas de propiedades mencionados anteriormente son polinomialmente resolubles. Para los sistemas de influencia, demostramos que computar la satisfacción (una medida equivalente al índice de Rae y similar al valor de Banzhaf) es difícil a menos que consideremos algunas restricciones en el modelo. Para los sistemas OLFM, una generalización de los sistemas OLF (van den Brink et al. 2011, 2012) proporcionamos una axiomatización para la medida de satisfacción. El segundo conjunto de resultados se refiere al análisis de redes sociales, y en particular con la definición de nuevas medidas de centralidad de redes sociales, que comparamos en redes reales con otras medidas de centralidad clásicas

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This work proposes ONTOCADE (Ontology-based Environment for Computer- Aided Domain Engineering), an ontology-based CASE environment for analysis and design in Multi-Agent Domain Engineering. Success in Multi-Agent Domain Engineering, the process of creating reusable software abstractions for the development of a set of multi-agent software applications in a domain or problem-solving area, depends on the availability of appropriate methodologies and tools providing adequate support for ontologies, communications, mobility, and autonomy, among others central topics of agent-based systems. ONTOCADE supports the application of the phases of MADEM, a methodology for Multi-Agent Domain Engineering. According to the rules of integration for composing an environment, its tools use a shared data model and incorporate the knowledge of methods for coordinating and guiding the execution of the phases of the software development lifecycle. For that, ONTOCADE is based on ontologies, structures particularly appropriate for representing knowledge and high-level software abstractions, because they present clear and unambiguous terminology. ONTOCADE uses a generic ontology, ONTOMADEM, for guiding the user in modeling tasks. To define ONTOMADEM, it was used the MADEM knowledge to generate a semantic network with the representation of the concepts of the methodology. For its design, the ONTOMADEM was generated by mapping the semantic network to an ontology represented by a hierarchy of classes. To function as a runtime environment, it was chosen Protégé, an extensible platform for creating knowledge-based applications. ONTOMADEM is an extension of the meta-ontology of Protégé. In this way, ONTOCADE executes as a plugin, that is, an aggregated component, which takes advantages of all the functionalities provided by Protégé and offers specifics functions, such as domain and architectural modeling.
Este trabalho propõe ONTOCADE (Ontology-based Environment for Computer- Aided Domain Engineering), um ambiente CASE baseado em ontologias para análise e projeto na Engenharia de Domínio Multiagente (EDMA). O sucesso da Engenharia de Domínio Multiagente, processo para criação de abstrações de software reutilizáveis para a construção de sistemas multiagentes em um domínio ou área de solução de problemas, depende da disponibilidade de metodologias e ferramentas que ofereçam adequadamente suporte para ontologias, comunicações, mobilidade, autonomia e outros tópicos centrais relacionados aos sistemas baseados em agentes. ONTOCADE fornece suporte à aplicação das fases da MADEM, uma metodologia para EDMA. De acordo com as regras de integração para a constituição de um ambiente, as ferramentas que o compõem utilizam um modelo de dados compartilhado e incorporam o conhecimento de métodos para coordenar e guiar a execução das fases do ciclo de desenvolvimento de software. Por esta razão, o ambiente ONTOCADE é baseado em ontologias, estruturas particularmente apropriadas para representar conhecimento e abstrações de software de alto nível, pois apresentam terminologia clara e não ambígua. ONTOCADE utiliza uma ontologia genérica, a ONTOMADEM, para guiar o usuário na realização da modelagem. Na definição da ONTOMADEM é utilizado o conhecimento da MADEM para gerar uma rede semântica com a representação dos conceitos da metodologia. No projeto, a ONTOMADEM é construída mapeando a rede semântica a uma ontologia representada por uma hierarquia de classes. Como ambiente de execução do ONTOCADE, foi escolhido o Protégé, uma plataforma extensível para a criação de aplicações baseadas em conhecimento. A ONTOMADEM é uma extensão à meta-ontologia do Protégé. Desta forma, o ONTOCADE executa como um plugin, ou seja, um componente agregado ao Protégé, que se serve de todas as funcionalidades providas pela plataforma e oferece suas funções específicas, tais como modelagem de domínio e modelagem arquitetural.

Une vaste quantité d'outils mathématiques permettant la modélisation et l'analyse des problèmes multi-agents ont récemment été développés dans le cadre de la théorie du transport optimal. Dans cette thèse, nous étendons pour la première fois plusieurs de ces concepts à des problématiques issues de la théorie du contrôle. Nous démontrons plusieurs résultats sur ce sujet, notamment des conditions nécessaires d'optimalité de type Pontryagin dans les espaces de Wasserstein, des conditions assurant la régularité intrinsèque de solutions optimales, des conditions suffisantes pour l'émergence de différents motifs, ainsi qu'un résultat auxiliaire à propos des arrangements de certaines singularités en géométrie sous-Riemannienne
A wealth of mathematical tools allowing to model and analyse multi-agent systems has been brought forth as a consequence of recent developments in optimal transport theory. In this thesis, we extend for the first time several of these concepts to the framework of control theory. We prove several results on this topic, including Pontryagin optimality necessary conditions in Wasserstein spaces, intrinsic regularity properties of optimal solutions, sufficient conditions for different kinds of pattern formation, and an auxiliary result pertaining to singularity arrangements in Sub-Riemannian geometry

In the era of information, emergent paradigms such as the Internet of Things with billions of devices constantly connected to the Internet exchanging heterogeneous data, demand new computing approaches for intelligent big data processing. Given this technological scenario, a suitable approach leverages on many computational entities, each of which performs tasks with low computational burden, conceived to be executed on multi-core and many-core architectures. To this aim, in this thesis, we propose Evolutive Agent Based Clustering (E-ABC) as promising framing reference. E-ABC is conceived to orchestrate a swarm of intelligent agents acting as individuals of an evolving population, each performing a random walk on a different subset of patterns. Each agent is in charge of discovering well-formed (compact and populated) clusters and, at the same time, a suitable subset of features corresponding to the subspace where such clusters lie, following a local metric learning approach, where each cluster is characterized by its own subset of relevant features. E-ABC is able to process data belonging to structured and possibly non-metric spaces, relying on custom parametric dissimilarity measures. Specifically, two variants are investigated. A first variant, namely E-ABC, aims at solving unsupervised problems, where agents’ task is to find well-formed clusters lying in suitable subspaces. A second variant, E-ABC^2, aims at solving classification problems by synthesizing a classification system on the top of the clusters discovered by the swarm. In particular, as a practical and real-world application, this novel classification system has been employed for recognizing and predicting localized faults on the electric distribution network of Rome, managed by the Italian utility company ACEA. Tests results show that E-ABC is able to synthesize classification models characterized by a remarkable generalization capability, with adequate performances to be employed in Smart Grids condition-based management systems. Moreover, the feature subsets where most of the meaningful clusters have been discovered can be used to better understand sub-classes of failures, each identified by a set of related causes.

碩士
東海大學
工業工程與經營資訊學系
94
Because of keen environment, customer demand makes great impact on the market trend and enterprise produces productions to fulfil customers` needs. However, the market direction changes frequently and violently, production lifecycle is brief, and forecasting the needs of customer is very difficult so that the capability of responsing the market variation fast become the crucial factor in gaining orders. In multi-site production enterprise has to consider material flow and capacity of every plant to avoid meeting the situation of resource shortage and surplus. And enterprise must be dependent on transmitting information in real-time to make a production planning and response customers` needs. The multi-agent technology has high suitability in dealing with the distributed problems, so we mention many references about agent-oriented system development methodology and multi-site architecture to analysis and design an agent-based multi-site production planning system. We want to make use of agents` feature, negotiation, to utilize the system we proposed efficient.