Thesis (M. Tech. (Engineering: Electrical)) -- Central University of technology, Free State, 2013 / The South African (SA) manufacturing industry requires developing similar levels of sophistication and expertise in automation as its international rivals to compete for global markets. To achieve this, manufacturing plants need to be managed extremely efficiently to ensure the quality of manufactured products and these plants must also have the relevant infrastructure. Furthermore, this industry must also compensate for rapid product introduction, product changes and short product lifespan. To support this need, this industry must engage in the current trend in automation known as reconfigurable manufacturing. The aim of the study is to develop a reconfigurable assembly system with enhanced control capabilities by utilizing virtual commissioning. In addition, this system must be capable of assembling multiple different products of a product range; reconfigure to accommodate the requirements of these products; autonomously reroute the product flow and distribute workload among assembly cells; handle erroneous products; and implement enhanced control methods. To achieve this, a literature study was done to confirm the type of components to be used, reveal design issues and what characteristics such a system must adhere to. Software named DELMIA was used to create a virtual simulation environment to verify the system and simultaneously scrutinize the methods of verification. On completion, simulations were conducted to verify software functions, device movements and operations, and the control software of the system. Based on simulation results, the physical system was built, and then verified with a multi agent system as overhead control to validate the entire system. The final results showed that the project objectives are achievable and it was also found that DELMIA is an excellent tool for system verification and will expedite the design of a system. By obtaining these results it is indicated that companies can design and verify their systems earlier through virtual commissioning. In addition, their systems will be more flexible, new products or product changes can be introduced more frequently, with minimum cost and downtime. This will enable SA manufacturing companies to be more competitive, ensure increased productivity, save time and so ensure them an advantage over their international competition.

Common control channels in cognitive radio (CR) ad hoc networks are spectrum resources temporarily allocated and commonly available to CR users for control message exchange. With no presumably available network infrastructure, CR users rely on cooperation to perform spectrum management functions. One the one hand, CR users need to cooperate to establish common control channels, but on the other hand, they need to have common control channels to facilitate such cooperation. This control channel problem is further complicated by primary user (PU) activities, channel impairments, and intelligent attackers. Therefore, how to reliably and securely establish control links in CR ad hoc networks is a challenging problem. In this work, a framework for control channel design and analysis is proposed to address control channel reliability and security challenges for seamless communication and spectral efficiency in CR ad hoc networks. The framework tackles the problem from three perspectives: (i) responsiveness to PU activities: an efficient recovery control channel method is devised to efficiently establish control links and extend control channel coverage upon PU's return while mitigating the interference with PUs, (ii) robustness to channel impairments: a reinforcement learning-based cooperative sensing method is introduced to improve cooperative gain and mitigate cooperation overhead, and (iii) resilience to jamming attacks: a jamming-resilient control channel method is developed to combat jamming under the impacts of PU activities and spectrum sensing errors by leveraging intrusion defense strategies. This research is particularly attractive to emergency relief, public safety, military, and commercial applications where CR users are highly likely to operate in spectrum-scarce or hostile environment.

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

This thesis addresses the problem of positional consensus of multi-agent systems. A positional consensus is achieved when the agents converge to a point. Some applications of this class of problem is in mid-air refueling of the aircraft or UAVs, targeting a geographical location, etc. In this research work some positional consensus algorithms have been developed. They can be categorized in two part (i) Broadcast control based algorithm (ii) Distributed control based algorithm. In case of broadcast based algorithm control strategies for a group of agents is developed to achieve positional consensus. The problem is constrained by the requirement that every agent must be given the same control input through a broadcast communication mechanism. Although the control command is computed using state information in a global framework, the control input is implemented by the agents in a local coordinate frame. The mathematical formulation has been done in a linear programming framework that is computationally less intensive than earlier proposed methods. Moreover, a random perturbation input in the control command, that helps to achieve reasonable proximity among agents even for a large number of agents, which was not possible with the existing strategy in the literature, is introduced. This method is extended to achieve positional consensus at a pre-specified location. A comparison between the LP approach and the existing SOCP based approach is also presented. Some of the algorithm has been demonstrated successfully on a robotic platform made from LEGO Mindstorms NXT Robots. In the second case of broadcast based algorithm, a decentralized algorithm for a group of multiple autonomous agents to achieve positional consensus has been developed using the broadcast concept. Even here, the mathematical formulation has done using a linear programming framework. Each agent has some sensing radius and it is capable of sensing position and orientation with other agents within their sensing region. The method is computationally feasible and easy to implement. In case of distributed algorithms, a computationally efficient distributed rendezvous algorithm for a group of autonomous agents has been developed. The algorithm uses a rectilinear decision domain (RDD), as against the circular decision domain assumed in earlier work available in the literature. This helps in reducing its computational complexity considerably. An extensive mathematical analysis has been carried out to prove the convergence of the algorithm. The algorithm has also been demonstrated successfully on a robotic platform made from LEGO Mindstorms NXT Robots.

Este trabalho apresenta um modelo de acompanhamento e atendimento de pacientes crônicos baseado nos conceitos de relacionamento de clientes utilizados nas empresas, mais especificamente aqueles presentes na tecnologia CRM (Customer Relationship Management). A esse modelo denominou-se Gestão do Relacionamento com o Paciente Crônico (GRPC). A tecnologia CRM é uma estratégia com ferramentas para implementar um programa de relacionamento e fidelidade entre o cliente/consumidor e o fornecedor. O modelo GRPC, ao utilizar o conceito de CRM no atendimento ao paciente, apresenta uma estratégia de acompanhamento e monitoramento de pacientes crônicos diferente da abordagem tradicional, muitas vezes baseada somente no tratamento da doença. Da mesma forma que o CRM consegue atingir os clientes dos mais variados níveis através dos seus canais de comunicação, neste modelo propõe-se utilizar a mesma tecnologia a fim de garantir um acompanhamento efetivo e adequado a todas as camadas populacionais. Para implementar o modelo GRPC propõe-se a criação de centrais de relacionamento de pacientes crônicos, que compõem a infra-estrutura do modelo ao combinar, de maneira adequada, a troca de informações, as campanhas, a transmissão e o processamento de dados, com a finalidade de melhorar o relacionamento com o paciente, através da tecnologia de telefonia e computação. Para uma avaliação preliminar do modelo, elaborou-se uma central de monitoração de pacientes diabéticos e desenvolveu-se um sistema de monitoração para diabéticos. A modelagem da central de monitoração foi feita utilizando-se a extensão da UML para a modelagem de negócio, o que permitiu analisar a abrangência do modelo. O sistema de monitoração, denominado TeleDM, foi desenvolvido visando a realizar as simulações necessárias para os estudos desse trabalho. A partir da modelagem de negócio elaboraram-se os modelos para o desenvolvimento do sistema. Após a avaliação de suas características optou-se por implementá-lo utilizando a tecnologia de orientação a agentes e objetos, o que permitiu verificar que tal combinação é adequada na solução de sistemas complexos com as características do sistema TeleDM. / This paper shows a chronic patient follow-up and attendance model based on the concepts of customers’ relationship used in the companies, mainly those existent in CRM technology (Customer Relationship Management). The model was designated as Chronic Patient Relationship Management (CPRM). The CRM technology is a strategy with tools to implement a relationship and fidelity program between the client / customer and the supplier. The CPRM model, by using the CRM concept on patient attendance, presents a strategy to follow-up and monitoring the chronic patient different from the usual traditional approach, which many times only consists in illness treatment. In the same way as the CRM, this model is able to reach clients of every condition through its communication channels; and suggests the use of the same technology in order to guarantee an effective and suitable follow-up for all social layers. To implement the CPRM model, the creation of relationship centers for chronic patients, thus building the model’s infrastructure when properly connecting the information exchange, campaigns, and data processing and transmitting, for the purpose of improving the relationship with the patient through telephone and computing technology. For a preliminary assessment of the model, a monitoring center was elaborated for diabetic patients, as well as a system for diabetes monitoring. The modeling of the center was done using the UML extension for business modeling, which allowed analyzing the model’s coverage. The monitoring system known, as TeleDM was developed to execute the simulations needed for this work’s studies. The models for the system’s development were elaborated from the business modeling. After evaluating its features, the choice was implementing it with agent and object-oriented technology, thus allowing checking this combination suitability for complex systems solution with the TeleDM system features.

Submitted by Maicon Juliano Schmidt (maicons) on 2015-07-09T14:56:04Z No. of bitstreams: 1 Luiz Rodrigo Jardim da Silva.pdf: 2565431 bytes, checksum: 6a2df89b794e9afe09546769e43ef4e9 (MD5) / Made available in DSpace on 2015-07-09T14:56:04Z (GMT). No. of bitstreams: 1 Luiz Rodrigo Jardim da Silva.pdf: 2565431 bytes, checksum: 6a2df89b794e9afe09546769e43ef4e9 (MD5) Previous issue date: 2013-01-31 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Problemas relacionados à heterogeneidade semântica vêm se mostrando atualmente como um importante campo de pesquisa. Dentro do contexto educacional, pesquisadores têm se dedicado ao desenvolvimento de novas tecnologias que visam melhorar os processos de localização, recuperação, catalogação, e reutilização de objetos de aprendizagem. Baseado neste cenário, destaca-se o uso de técnicas de alinhamento de ontologias para prover integração entre ontologias distintas. Assim, o objetivo deste trabalho é desenvolver uma ferramenta que forneça mecanismos de busca semântica de objetos de aprendizagem com suporte a alinhamento automático de ontologias. / Semantics heterogeneity problems are becoming an important field of research. Within the educational context, researchers have focused on developing new technologies to improve the processes of localization, retrieval, cataloging, and reuse of learning objects. This scenario highlights the use of ontology alignment techniques to provide integration between different ontologies. Therefore, the goal of the present work is to develop a tool that provides mechanisms for semantic search of learning objects, with support for automatic aligning ontologies.

Este trabalho apresenta um modelo de acompanhamento e atendimento de pacientes crônicos baseado nos conceitos de relacionamento de clientes utilizados nas empresas, mais especificamente aqueles presentes na tecnologia CRM (Customer Relationship Management). A esse modelo denominou-se Gestão do Relacionamento com o Paciente Crônico (GRPC). A tecnologia CRM é uma estratégia com ferramentas para implementar um programa de relacionamento e fidelidade entre o cliente/consumidor e o fornecedor. O modelo GRPC, ao utilizar o conceito de CRM no atendimento ao paciente, apresenta uma estratégia de acompanhamento e monitoramento de pacientes crônicos diferente da abordagem tradicional, muitas vezes baseada somente no tratamento da doença. Da mesma forma que o CRM consegue atingir os clientes dos mais variados níveis através dos seus canais de comunicação, neste modelo propõe-se utilizar a mesma tecnologia a fim de garantir um acompanhamento efetivo e adequado a todas as camadas populacionais. Para implementar o modelo GRPC propõe-se a criação de centrais de relacionamento de pacientes crônicos, que compõem a infra-estrutura do modelo ao combinar, de maneira adequada, a troca de informações, as campanhas, a transmissão e o processamento de dados, com a finalidade de melhorar o relacionamento com o paciente, através da tecnologia de telefonia e computação. Para uma avaliação preliminar do modelo, elaborou-se uma central de monitoração de pacientes diabéticos e desenvolveu-se um sistema de monitoração para diabéticos. A modelagem da central de monitoração foi feita utilizando-se a extensão da UML para a modelagem de negócio, o que permitiu analisar a abrangência do modelo. O sistema de monitoração, denominado TeleDM, foi desenvolvido visando a realizar as simulações necessárias para os estudos desse trabalho. A partir da modelagem de negócio elaboraram-se os modelos para o desenvolvimento do sistema. Após a avaliação de suas características optou-se por implementá-lo utilizando a tecnologia de orientação a agentes e objetos, o que permitiu verificar que tal combinação é adequada na solução de sistemas complexos com as características do sistema TeleDM. / This paper shows a chronic patient follow-up and attendance model based on the concepts of customers’ relationship used in the companies, mainly those existent in CRM technology (Customer Relationship Management). The model was designated as Chronic Patient Relationship Management (CPRM). The CRM technology is a strategy with tools to implement a relationship and fidelity program between the client / customer and the supplier. The CPRM model, by using the CRM concept on patient attendance, presents a strategy to follow-up and monitoring the chronic patient different from the usual traditional approach, which many times only consists in illness treatment. In the same way as the CRM, this model is able to reach clients of every condition through its communication channels; and suggests the use of the same technology in order to guarantee an effective and suitable follow-up for all social layers. To implement the CPRM model, the creation of relationship centers for chronic patients, thus building the model’s infrastructure when properly connecting the information exchange, campaigns, and data processing and transmitting, for the purpose of improving the relationship with the patient through telephone and computing technology. For a preliminary assessment of the model, a monitoring center was elaborated for diabetic patients, as well as a system for diabetes monitoring. The modeling of the center was done using the UML extension for business modeling, which allowed analyzing the model’s coverage. The monitoring system known, as TeleDM was developed to execute the simulations needed for this work’s studies. The models for the system’s development were elaborated from the business modeling. After evaluating its features, the choice was implementing it with agent and object-oriented technology, thus allowing checking this combination suitability for complex systems solution with the TeleDM system features.

<p>The agent technology represents one of the most consistent approaches to distributed artificial intelligence. Agents are characterized by autonomous, reactive, proactive, and social behavior.&nbsp;In addition, more complex, intelligent agents are often defined&nbsp;in terms of human-like mental attitudes, such as beliefs, desires,&nbsp;and intentions.</p><p>This thesis deals with software agents and multiagent systems&nbsp;in several ways. First, it defines a new reasoning architecture&nbsp;for intelligent agents called<em> Distributed Non-Axiomatic Reasoning System </em>(DNARS). Instead of the popular Belief-Intention-Desire model, it uses Non-Axiomatic Logic, a formalism developed for the domain of articial general intelligence. DNARS&nbsp;is highly-scalable, capable of answering questions and deriving&nbsp;new knowledge over large knowledge bases, while, at the same&nbsp;time, concurrently serving large numbers of external clients.&nbsp;</p><p>Secondly, the thesis proposes a novel agent runtime environment&nbsp;named<em> Siebog.</em> Based on the modern web and enterprise stan-dards, Siebog tries to reduce the gap between the agent technology and industrial applications. Like DNARS, Siebog is a&nbsp;distributed system. Its server side runs on computer clusters&nbsp;and provides advanced functionalities, such as automatic agent&nbsp;load-balancing and fault-tolerance. The client side, on the other<br />hand, runs inside web browsers, and supports a wide variety of&nbsp;hardware and software platforms.</p><p>Finally, Siebog depends on DNARS for deploying agents with&nbsp;unique reasoning capabilities.</p> / null / <p>Agentska tehnologija predstavlja dosledan pristup razvoju distribuirane ve&scaron;tačke&nbsp; inteligencije. Ono &scaron;to agente izdvaja od ostalih pristupa su autonomno, reaktivino,&nbsp; pro-aktivno, i socijalno pona&scaron;anje. Pored toga, kompleksniji, inteligentni agenti se često defini&scaron;u koristeći ljudske mentalne konstrukcije, kao sto su verovanja, želje i namere.</p><p>Disertacija se bavi softverskim agentima i multiagentskim sistemima sa nekoliko aspekata. Prvo, definisana je nova&nbsp; arhitektura za rasuđivanje sa primenom u razvoju&nbsp; inteligentnih agenata, nazvana Distribuirani sistem za ne-aksiomatsko rasuđivanje&nbsp; (eng. <em>Distributed Non-Axiomatic Reasoning System</em>) (DNARS). Umesto popularnog&nbsp;&nbsp; BDI modela za razvoj inteligentnih agenata (eng. <em>Belief-Desire-Intention</em>),&nbsp; arhitektura&nbsp; se zasniva na tzv. <em>ne-aksiomatskoj</em> logici, formalizmu razvijenom u domenu ve&scaron;tačke&nbsp; op&scaron;te inteligencije. DNARS je skalabilan softverski sistem, sposoban da odgovara na&nbsp;&nbsp; pitanja i da izvodi nove zaključke na osnovu veoma velikih&nbsp; baza znanja, služeći pri&nbsp;&nbsp; tome veliki broj klijenata.</p><p>Zatim, u disertaciji je predložena nova multiagentska platforma nazvana Siebog. Siebog je zasnovan na modernim standardima za razvoj veb aplikacija, čime poku&scaron;ava da smanji razliku izmedu multiagentskih sistema i sistema koji se koriste u&nbsp;industriji. Kao DNARS, i Siebog je distribuiran sistem. Na serverskoj strani, Siebog se izvr&scaron;ava na računarskim klasterima, pružajući napredne funkcionalnosti, poput automatske distribucije agenata i otpornosti na gre&scaron;ke. Sa klijentske strane, Siebog&nbsp;se izvr&scaron;ava u veb pretrazivačima i podržava &scaron;iroku lepezu hardverskih i softverskih platformi.</p><p>Konačno, Siebog se oslanja na DNARS za ravoj agenata sa jedinstvenim sposobnostima za rasuđivanje.</p>

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

Cette thèse d'HDR en anglais, présente l'essentiel de mes travaux de 1996 à 2005. Voir le résumé anglais pour plus de détails.