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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Taming NFV orchestration using decentralised cognitive components / Orquestrador NFV descentralizado baseado em raciocínio BDI

Schardong, Frederico January 2018 (has links)
Network Functions Virtualisation (NFV) separa as funções de rede dos dispositivos físicos, simplificando a implantação de novos serviços. As típicas funções de rede, como firewalls, aceleradores de tráfego, sistemas de detecção de intrusão e sistemas de prevenção de intrusões, são tradicionalmente realizadas por equipamentos físicos proprietários, que devem ser instalados manualmente pelos operadores de rede. A implantação de equipamentos físicos é desafiadora porque eles têm requisitos específicos de encadeamento e ordenação. Ao contrário dos equipamentos físicos tradicionais, as funções de rede virtuais (VNFs) podem ser dinamicamente implementadas e reconfiguradas sob demanda, colocando desafios de gerenciamento rigorosos aos sistemas em rede. A seleção das VNFs mais apropriadas para atingir um objetivo específico e a decisão sobre onde implantar essas VNFs e por quais caminhos elas se comunicarão são responsabilidades de um orquestrador de NFV. Nesta dissertação, propomos orquestrar VNFs usando componentes cognitivos interativos estruturados com a arquitetura belief-desire-intention (BDI), levando a soluções emergentes para enfrentar os desafios da rede. A arquitetura BDI inclui um ciclo de raciocínio que fornece aos agentes um comportamento racional, permitindo que lidem com diferentes cenários nos quais o comportamento flexível e inteligente é necessário. Estendemos a arquitetura NFV substituindo seu orquestrador centralizado por agentes BDI. Nossa proposta inclui um protocolo de leilão reverso e uma nova heurística de licitação que permite que os agentes tomem decisões sobre as tarefas de orquestração. Por fim, nós fornecemos uma plataforma de testes que integra uma plataforma para o desenvolvimento de agentes BDI com um emulador de rede, permitindo que os agentes controlem as VNFs e percebam a rede. Essa plataforma de testes é usada para implementar VNFs e avaliar empiricamente nosso modelo teórico em um ataque de negação de serviço distribuído. Os resultados da avaliação mostram que uma solução para o ataque DDoS surge através da negociação de agentes, mitigando com sucesso o ataque. / Network Functions Virtualisation (NFV) decouples network functions from physical devices, simplifying the deployment of new services. Typical network functions, like firewalls, traffic accelerators, intrusion detection systems and intrusion prevention systems, are traditionally performed by proprietary physical appliances, which must be manually installed by network operators. Their deployment is challenging because they have specific chaining requirements. As opposed to traditional physical appliances, virtual network functions (VNFs) can be dynamically deployed and reconfigured on demand, posing strict management challenges to networked systems. The selection of the most appropriate VNFs to achieve a particular objective, the decision on where to deploy these VNFs and through which paths they will communicate are the responsibilities of an NFV orchestrator. In this dissertation, we propose to orchestrate VNFs using interacting cognitive components structured with the belief-desire-intention (BDI) architecture, leading to emergent solutions to address network challenges. The BDI architecture includes a reasoning cycle, which provides agents with rational behaviour, allowing agents to deal with different scenarios in which flexible and intelligent behaviour is needed. We extend the NFV architecture, replacing its centralised orchestrator with BDI agents. Our proposal includes a reverse auction protocol and a novel bidding heuristic that allow agents to make decisions regarding the orchestration tasks. Finally, we provide a testbed that integrates a platform for developing BDI agents with a network emulator, allowing agents to control VNFs and perceive the network. This testbed is used to implement VNFs and empirically evaluate our theoretical model in a distributed denial-of-service (DDoS) attack. The evaluation results show that a solution to the DDoS attack emerges through the negotiation of agents, successfully mitigating the attack.
112

Automated service negotiation between autonomous computational agents

Faratin, Peyman January 2000 (has links)
Multi-agent systems are a new computational approach for solving real world, dynamic and open system problems. Problems are conceptualized as a collection of decentralised autonomous agents that collaborate to reach the overall solution. Because of the agents autonomy, their limited rationality, and the distributed nature of most real world problems, the key issue in multi-agent system research is how to model interactions between agents. Negotiation models have emerged as suitable candidates to solve this interaction problem due to their decentralised nature, emphasis on mutual selection of an action, and the prevalence of negotiation in real social systems. The central problem addressed in this thesis is the design and engineering of a negotiation model for autonomous agents for sharing tasks and/or resources. To solve this problem a negotiation protocol and a set of deliberation mechanisms are presented which together coordinate the actions of a multiple agent system. In more detail, the negotiation protocol constrains the action selection problem solving of the agents through the use of normative rules of interaction. These rules temporally order, according to the agents' roles, communication utterances by specifying both who can say what, as well as when. Specifically, the presented protocol is a repeated, sequential model where offers are iteratively exchanged. Under this protocol, agents are assumed to be fully committed to their utterances and utterances are private between the two agents. The protocol is distributed, symmetric, supports bi and/or multi-agent negotiation as well as distributive and integrative negotiation. In addition to coordinating the agent interactions through normative rules, a set of mechanisms are presented that coordinate the deliberation process of the agents during the ongoing negotiation. Whereas the protocol normatively describes the orderings of actions, the mechanisms describe the possible set of agent strategies in using the protocol. These strategies are captured by a negotiation architecture that is composed of responsive and deliberative decision mechanisms. Decision making with the former mechanism is based on a linear combination of simple functions called tactics, which manipulate the utility of deals. The latter mechanisms are subdivided into trade-off and issue manipulation mechanisms. The trade-off mechanism generates offers that manipulate the value, rather than the overall utility, of the offer. The issue manipulation mechanism aims to increase the likelihood of an agreement by adding and removing issues into the negotiation set. When taken together, these mechanisms represent a continuum of possible decision making capabilities: ranging from behaviours that exhibit greater awareness of environmental resources and less to solution quality, to behaviours that attempt to acquire a given solution quality independently of the resource consumption. The protocol and mechanisms are empirically evaluated and have been applied to real world task distribution problems in the domains of business process management and telecommunication management. The main contribution and novelty of this research are: i) a domain independent computational model of negotiation that agents can use to support a wide variety of decision making strategies, ii) an empirical evaluation of the negotiation model for a given agent architecture in a number of different negotiation environments, and iii) the application of the developed model to a number of target domains. An increased strategy set is needed because the developed protocol is less restrictive and less constrained than the traditional ones, thus supporting development of strategic interaction models that belong more to open systems. Furthermore, because of the combination of the large number of environmental possibilities and the size of the set of possible strategies, the model has been empirically investigated to evaluate the success of strategies in different environments. These experiments have facilitated the development of general guidelines that can be used by designers interested in developing strategic negotiating agents. The developed model is grounded from the requirement considerations from both the business process management and telecommunication application domains. It has also been successfully applied to five other real world scenarios.
113

A computational model of Lakatos-style reasoning

Pease, Alison January 2007 (has links)
Lakatos outlined a theory of mathematical discovery and justification, which suggests ways in which concepts, conjectures and proofs gradually evolve via interaction between mathematicians. Different mathematicians may have different interpretations of a conjecture, examples or counterexamples of it, and beliefs regarding its value or theoremhood. Through discussion, concepts are refined and conjectures and proofs modified. We hypothesise that: (i) it is possible to computationally represent Lakatos's theory, and (ii) it is useful to do so. In order to test our hypotheses we have developed a computational model of his theory. Our model is a multiagent dialogue system. Each agent has a copy of a pre-existing theory formation system, which can form concepts and make conjectures which empirically hold for the objects of interest supplied. Distributing the objects of interest between agents means that they form different theories, which they communicate to each other. Agents then find counterexamples and use methods identified by Lakatos to suggest modifications to conjectures, concept definitions and proofs. Our main aim is to provide a computational reading of Lakatos's theory, by interpreting it as a series of algorithms and implementing these algorithms as a computer program. This is the first systematic automated realisation of Lakatos's theory. We contribute to the computational philosophy of science by interpreting, clarifying and extending his theory. We also contribute by evaluating his theory, using our model to test hypotheses about it, and evaluating our extended computational theory on the basis of criteria proposed by several theorists. A further contribution is to automated theory formation and automated theorem proving. The process of refining conjectures, proofs and concept definitions requires a flexibility which is inherently useful in fields which handle ill-specified problems, such as theory formation. Similarly, the ability to automatically modify an open conjecture into one which can be proved, is a valuable contribution to automated theorem proving.
114

Norm awareness for virtual characters behaviour : a socio-cognitive approach

Lee, JeeHang January 2015 (has links)
Social intelligence has a huge impact on the determination of human behaviour in the society. The use of norms can contribute to advances in this social intelligence by the provision of appropriate behaviour based upon the understanding of social situations. Hence, the domain of virtual characters research has given much attention to take advantage of these characteristics of norms particularly in engineering human-like behaviour. However, a lack of capability in reasoning about norms as well as a lack of norm autonomy in virtual characters have significantly diminished the naturalism in virtual characters behaviour. Within this context, a hybrid approach incorporating social and individual reasoning inspired by socio-cognitive theory is taken into account in this thesis. To this end, we propose DNA 3 , Distributed Norm Aware Agent Architecture, established through the integration of (i) the institution, a normative framework performing the social reasoning, (ii) N-Jason, a (BDI-type) cognitive agent carrying out run-time norm-aware deliberation and (iii) a virtual character in charge of perception and realisation of actions. The institution takes responsibility of (i) analysis of state of external worlds by recording a sequence of event occurrences observed by multiple virtual agents, (ii) reasoning about situationally appropriate behaviour with an assistance from Answer Set Programming (ASP) solver depending upon the social context virtual characters encounter and (iii) in turn detachment of a new set of norms, more precisely normative consequences of specific actions, to virtual characters. This contributes to the enhancement in the flexibility in specifying and reasoning about social norms subject to changes of social situations. Those detached norms are involved in the reasoning process of in- dividual virtual characters. In here, a norm-aware BDI-type agent, N-Jason, performs a practical reasoning to select a plan to execute between norms and goals. Basically, N-Jason offers a generic norm execution mechanism on top of norm aware deliberation to contribute to the exploitation of run-time norm compliance. The selection of agent behaviour is achieved in the norm-aware deliberation process by intention scheduling with deadlines and priorities. This improves the rationality in the choice of behaviour with taking into account the preference on norms and goals in agent mind by evaluation of the importance and imminence between feasible plans triggered by both norms and goals. The design and simulation of politeness is presented as an evaluation of DNA 3 with respect to the effectiveness and adequacy in modelling virtual characters behaviour. The emphasis in here lies on the capability that is able to exhibit different types of appropriate polite behaviour in response to frequent changes in social situations. This is mainly driven by two main activities: prediction of other participants’ intention is carried out by norm-aware virtual characters whilst the understanding of context and reasoning about relevant social behaviour is performed in normative frameworks. For this purpose, three case studies are provided in this thesis: (i) politeness in navigation of individuals, (ii) politeness in the formation and navigation of groups during a guided tour, and(iii) evacuation model as a politeness in the emergency situation. The evaluation is conducted by measuring: (i) the appropriateness of in response to scenarios (e.g.a number of avoiding collisions) and (ii) the reliability of agent decision making (e.g. a response time in relation to norms with the highest priority and the most urgent).
115

Um modelo de sistema AVA-SMA orientado à legislação

Moreira, Maria Isabel Giusti January 2017 (has links)
Dentro da Educação a Distância (EaD), os softwares de apoio como os Ambientes Virtuais de Aprendizagem (AVA) são considerados recursos que favorecem a comunicação entre os atores envolvidos, permitindo a troca de informação. Atribuir Inteligência Artificial a esses AVAs, utilizando Sistemas Multiagentes (SMA) e uma forma de procurar que os mesmos tenham um bom desempenho e que seus recursos facilitem o processo de aprendizagem. Esse trabalho cont em um estudo sobre os principais AVAs existentes e sobre os métodos alternativos de integração de AVA com SMA. Ao analisar o estado da arte dos AVAs pode-se observar que todos trabalham como ferramentas de auxílio ao aluno, por em nenhum deles trabalha aspectos da gestão da EaD dando suporte aos aspectos relevantes da legislação dessa modalidade. Por esse motivo, essa Tese tem por objetivo a criação de um modelo de integração AVA-SMA que possa tornar o AVA MOODLE capaz de auxiliar os gestores da EaD em suas diferentes tarefas, com base na incorporação, ao mesmo, de um modelo de representação de legislação. Para realizar essa integração do modelo AVA-SMA orientado a Legislação foi desenvolvido um espec co modelo organizacional de Sistema Multiagente. Por m com base em um estudo de caso, ser a realizado simulações para veri car as funcionalidades do Modelo de Sistema AVA-SMA orientado a Legislação, proposto nesta Tese. / In Distance Learning (EaD), supporting software such as Virtual Learning Environments (VLE) are considered resources that favor communication between the actors involved, allowing the exchange of information. Assigning Arti cial Intelligence to these VLEs, using Multi-Agent Systems (MAS) is a way of ensuring they have a good performance and that its resources facilitate the learning process. This work contains a study on the major existing VLEs and on alternative methods to integrate VLE with MAS. When analyzing the state of the art of the VLEs it is possible to see that all of them work as aid tools for students, but none of them work on management aspects of distance learning that support the relevant aspects of the legislation for this type of education. Therefore, this thesis aims to create a VLE-MAS integration model that can make the VLE MOODLE able to help distance learning managers in their di erent tasks, based on incorporating a legislation representation model to it. To accomplish this integration of the legislation-oriented VLE-MAS model, a speci c Multi-Agent System organizational model was developed. At last, based on a case study, simulations will be conducted to verify the functionalities of the VLE-MAS System Model oriented to legislation, proposed in this thesis.
116

Sistema minimamente invasivo baseado em agentes aplicado em controladores lógicos programáveis

Peixoto, João Alvarez January 2016 (has links)
A indústria carece de sistemas produtivos que atendam a diversidade de demanda do mercado, com eficiência e capacidade de adaptação rápida. As novas soluções para estas necessidades remetem ao uso de novas tecnologias de automação. Porém, a maioria dos sistemas integrados de manufatura implantados em indústria possui seu gerenciamento por controladores lógicos programáveis, assim como suas interligações elétricas e lógicas de controle. A tese proposta faz uso de Sistemas Multiagentes em controladores lógicos programáveis, para que estes possam controlar seus sistemas de manufatura, propiciando-lhes os requisitos de diversidade, agilidade e auto-organização no meio produtivo. A comprovação desta tese se dá pelo método desenvolvido para que tal implementação aconteça, bem como pela análise de abrangência deste método, a fim de verificar em quais cenários ele é eficaz. O método proposto analisa o controlador lógico programável e descreve uma rotina de ações a serem seguidas para que ele se insira em Sistemas Multiagentes, valendo-se das funcionalidades que um agente pode oferecer. Sua análise de aplicação ocorreu em três cenários distintos, onde a abordagem por sistemas auto-organizáveis apresentou melhores resultados para atingir os requisitos de diversidade, agilidade e auto-organização, a partir de sistemas multiagentes interagindo com os controladores lógicos programáveis e suas lógicas locais. / The industry needs production systems that attend the diversity of market demand, with efficiency and fast adaptability. The new solutions to these needs refer to the use of new automation technologies. However, most integrated manufacturing systems deployed in industry have its management by programmable logic controllers as well as their electrical interconnections and logics of control. The thesis proposal indicates the use of multi-agent systems on programmable logic controllers, so that they are able to control their manufacturing systems, addressing the requirements of diversity, self-organizing and agility to the productive environment. The proof of this thesis is given by the method developed for such implementation to happen, as well as analysis of the scope of this method in order to verify in what scenarios it is effective. The proposed method analyzes the programmable logic controller and describes a routine of actions to follow so that it may enter into a multi-agent system, using the features that an agent can offer. Its application analysis took place in three different scenarios where the approach by self-organizing systems showed better results for achieving the requirements of diversity, agility and self-organization from multi-agent systems interacting with programmable logic controllers and their local logic.
117

GOAL DELIBERATION AND PLANNING IN COOPERATIVE MULTI-ROBOT SYSTEMS

Yongho Kim (5929901) 17 January 2019 (has links)
Intelligent robots are rational agents. The rationality of robots working cooperatively is significantly different from robots working independently. Cooperation between intelligent robots requires the high level of reasoning and complex interactions for successful operations. The required reasoning process includes knowledge representation and sharing as well as the ability to understand the context of a situation. The reasoning process heavily influences on the planning of deciding what actions need to be taken. Goal deliberation and planning is the process that deals with those requirements. This dissertation investigates the problem of goal deliberation and planning to enable such cooperation between goal-oriented intelligent robots, working as a team. The dissertation then proposes a multi-robot system model that embraces results of the investigation. The proposed model is realized on the top of the platform ‘robot operating system’ (ROS). The implemented system, named ‘goal-oriented multi agent systems’ (GOMAS), is demonstrated with the computer game, StarCraft II. Units in StarCraft II are individually controlled by the GOMAS robots and work cooperatively to attain a set of goals given from operators. The demonstration with the three different scenarios validates that the GOMAS system successfully and efficiently deliberates and plans the given goals.
118

A agência na abordagem multinível da transição sociotecnológica sustentável

Chevarria, Diego Gonzales January 2016 (has links)
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.
119

Apprentissage artificiel collectif ; aspects dynamiques et structurels / Collective machine learning ; structural and dynamic aspects

Veillon, Lise-Marie 08 March 2018 (has links)
L’apprentissage collectif dans un système multi-agents considère comment une communauté constituée d’agents autonomes partageant un même objectif d’apprentissage peut bénéficier, au niveau individuel et collectif, d’échanges structurés d’informations. Les agents, reliés par un réseau de communication, ont tous la faculté de percevoir des observations, appelées exemples d’apprentissage. Cette thèse s’appuie sur un protocole pré-existant, SMILE (Sound-Multi-agent-Incremental-LEarning), qui organise un échange parcimonieux d’exemples et d’hypothèses. Ce protocole garantit, dans le cas d’agents tous connectés, que les agents obtiennent une hypothèse qui tient compte de tous les exemples perçus par l’ensemble des agents. Il existe des variantes séquentielles de ce protocole qui mettent en place une propagation de l’information pour offrir les mêmes garanties dans un réseau, non pas complet mais, connexe.Cette thèse apporte deux nouveaux éclairages sur l’apprentissage artificiel collectif. Une première étude montre l’influence de la structure du réseau sur l’apprentissage avec un protocole dont les communications sont limitées au voisinage, sans propagation. Une seconde contribution présente et analyse un nouveau protocole, Waves, qui préserve les garanties de SMILE et dont les interactions en parallèle rendent l’apprentissage en réseau plus dynamique. Ce protocole est évalué en détail,dans un contexte simplifié de tour par tour, ce qui permet de le raffiner par la suite avec diverses améliorations. Il est cependant conçu pour s’adapter à un apprentissage en ligne et une acquisition non limitée, ni en temps ni en nombre, de nouveaux exemples par la communauté. / Collective learning in multi-agent systems considers how a community of autonomous agents sharing a learning purpose may benefit from exchanging information to learn efficiently as a community as well as individuals. The community forms a communication network where each agent may accesses observations, called learning examples. This thesis is based on a former protocol, SMILE (Sound-Multi-agent-Incremental-LEarning), which sets up parsimonious examples and hypotheses exchanges between agents. In a fully connected community, this protocol guarantees an agent’s hypothesis takes into account all the examples obtained by the community. Some sequential protocols add propagation to SMILE in order to extend this consistency guarantee to other connected networks. This thesis contribution to the artificial collective learning field is two fold.First, we investigate the influence of network structures on learning in networks when communication is limited to neighbourhood without further information propagation. Second, we present and analyze a new protocol, Waves, with SMILE’s guarantees and a more dynamic learning process thanks to its execution in parallel. The evaluation of this protocol in a simple turn-based setting gives the opportunity to improve it here in multiple ways. It is however meant to be used with online learning without any restriction on the acquisition rate of new examples, neither on speed nor number.
120

Decentralized control of multi-agent aerial transportation system

Toumi, Noureddine 04 1900 (has links)
Autonomous aerial transportation has multiple potential applications including emergency cases and rescue missions where ground intervention may be difficult. In this context, the following work will address the control of multi-agent Vertical Take-off and Landing aircraft (VTOL) transportation system. We develop a decentralized method. The advantage of such a solution is that it can provide better maneuverability and lifting capabilities compared to existing systems. First, we consider a cooperative group of VTOLs transporting one payload. The main idea is that each agent perceive the interaction with other agents as a disturbance while assuming a negotiated motion model and imposing certain magnitude bounds on each agent. The theoretical model will be then validated using a numerical simulation illustrating the interesting features of the presented control method. Results show that under specified disturbances, the algorithm is able to guarantee the tracking with a minimal error. We describe a toolbox that has been developed for this purpose. Then, a system of multiple VTOLs lifting payloads will be studied. The algorithm assures that the VTOLs are coordinated with minimal communication. Additionally, a novel gripper design for ferrous objects is presented that enables the transportation of ferrous objects without a cable. Finally, we discuss potential connections to human in the loop transportation systems.

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