Abstract Ubiquitous computing transforms physical environments into smart spaces, supporting users in an unobtrusive fashion. Such support requires sensing and interpreting the situation of the user, and providing the required functionality utilizing resources available. In other words, context acquisition, context modelling, and context reasoning are required. This thesis explores rule-based context reasoning from three perspectives: to implement the functionality of ubiquitous applications, to support the creation of ubiquitous applications, and to achieve self-adaptation. First, implementing functionality with reasoning is studied by comparing an application equipped with rule-based reasoning with an application providing similar functionality with hard coded application logic. The scalability of rule-based reasoning is studied with a large-scale student assistant scenario. Reasoning with constrained resources is explored with an application that performs reasoning partially on mobile devices. Finally, distributing a reasoning component that supports smart space interaction is explored with centralized, hybrid, and distributed architectures. Second, the creation of applications with rule-based reasoning is explored. In the first study, rules support building applications from available services and resources based on the instructions that users give via physical user interfaces. The second study supports developers, by proposing middleware that dynamically selects services and data based on the rules written by application developers. Third, self-adaptation is explored with a conceptual framework that adds self-introspective monitoring and control to smart space applications. This framework is verified with simulation and theoretical studies, and an application that fuses diverse data to provide fuel-efficient driving recommendations and adapts decision-making based on the driver’s progress and feedback. The thesis’ contributions include demonstrative cases on using rule-based reasoning from different perspectives, different scales, and with different architectures. Frameworks, a middleware, simulations, and prototypes provide the concrete contribution of the thesis. Generally, the thesis contributes to understanding how rule-based reasoning can be used in ubiquitous computing. The results presented can be used as guidelines for developers of ubiquitous applications. / Tiivistelmä Jokapaikan tietotekniikka muokkaa fyysisen ympäristömme älykkääksi tilaksi, joka tukee käyttäjää häntä häiritsemättä. Tuki toteutetaan asentamalla ympäristöön käyttäjää ja ympäristöä havainnoivia laitteita, tulkitsemalla kerätyn tiedon perusteella käyttäjän tilanne ja tarjoamalla tilanteeseen sopiva toiminnallisuus käyttäen saatavilla olevia resursseja. Toisin sanoen, älykkään tilan on kyettävä tunnistamaan ja mallintamaan toimintatilanne sekä päättelemään toimintatilanteen perusteella. Tässä työssä tutkitaan sääntöpohjaista päättelyä toimintatilanteen perusteella sovellusten toiminnallisuuden toteutuksen, kehittämisen tuen sekä mukautuvuuden näkökulmista. Sovellusten toiminnallisuuden toteuttamista päättelemällä tutkitaan vertaamalla sääntöpohjaisen päättelyn avulla toteutettua toiminnallisuutta vastaavaan suoraan sovellukseen ohjelmoituun toiminnallisuuteen. Sääntöpohjaisen päättelyn skaalautuvuutta arvioidaan laajamittaisessa opiskelija-assistenttiskenaariossa. Niukkojen resurssien vaikutusta päättelyyn arvioidaan päättelemällä osittain mobiililaitteessa. Älykkään tilan vuorovaikutusta tukevan päättelykomponentin hajauttamista tutkitaan keskitetyn, hybridi- ja hajautetun arkkitehtuurin avulla. Sovelluskehityksen tukemiseksi päättelyn säännöt muodostetaan saatavilla olevista palveluista ja resursseista käyttäjän fyysisen käyttöliittymän välityksellä antamien ohjeiden mukaisesti. Toisessa tapauksessa sovelluskehitystä tuetaan väliohjelmistolla, joka valitsee palvelut ja datan dynaamisesti sovelluskehittäjien luomien sääntöjen perusteella. Mukautuvuutta tutkitaan tilan hallintaan ja itsehavainnointiin liittyvän toiminnallisuuden lisäämiseen pystyvän käsitteellisen kehyksen avulla. Kehyksen toiminta varmennetaan simulointien sekä teoreettisten tarkastelujen avulla. Toteutettu useita datalähteitä yhdistävä sovellus antaa ajoneuvon kuljettajalle polttoaineen kulutuksen vähentämiseen liittyviä suosituksia sekä mukautuu kuljettajan ajotavan kehityksen ja palautteen perusteella. Työssä on osoitettu sääntöpohjaisen päättelyn toimivuus eri näkökulmista, eri skaalautuvuuden asteilla sekä eri arkkitehtuureissa. Työn konkreettisia tuloksia ovat kehykset, väliohjelmistot, simuloinnit sekä prototyypit. Laajemmassa mittakaavassa työ edesauttaa ymmärtämään sääntöpohjaisen päättelyn soveltamista ja työn tuloksia voidaankin käyttää suosituksina sovelluskehittäjille.

The growing development and use of pervasive systems, equipped with increasingly sophisticated functionalities and communication means, offer fantastic potentialities of services, particularly in the eHealth and Telemedicine domains, for the benifit of each citizen, patient or healthcare professional. One of the current societal challenges is to enable a better exploitation of the available services for all actors involved in a given domain. Nevertheless, the multiplicity of the offered services, the systems functional variety, and the heterogeneity of the needs require the development of knowledge models of these services, systems functions, and needs. In addition, the distributed computing environments heterogeneity, the availability and potential capabilities of various human and material resources (devices, services, data sources, etc.) required by the different tasks and processes, the variety of services providing users with data, the interoperability conflicts between schemas and data sources are all issues that we have to consider in our research works. Our contribution aims to empower the intelligent exploitation of ubiquitous resources and to optimize the quality of service in ambient environment. For this, we propose a knowledge meta-model of the main concepts of a pervasive environment, such as Actor, Task, Resource, Object, Service, Location, Organization, etc. This knowledge meta-model is based on ontologies describing the different aforementioned entities from a given domain and their interrelationships. We have then formalized it by using a standard language for knowledge description. After that, we have designed an architectural framework called ONOF-PAS (ONtology Oriented Framework for Pervasive Applications and Services) mainly based on ontological models, a set of rules, an inference engine, and object oriented components for tasks management and resources processing. Being generic, extensible, and applicable in different domains, ONOF-PAS has the ability to perform rule-based reasoning to handle various contexts of use and enable decision making in dynamic and heterogeneous environments while taking into account the availability and capabilities of the human and material resources required by the multiples tasks and processes executed by pervasive systems. Finally, we have instantiated ONOF-PAS in the telemedicine domain to handle the scenario of the transfer of persons victim of health problems during their presence in hostile environments such as high mountains resorts or geographically isolated areas. A prototype implementing this scenario, called T-TROIE (Telemedicine Tasks and Resources Ontologies for Inimical Environments), has been developed to validate our approach and the proposed ONOF-PAS framework.

Cette thèse porte sur le Web Sémantique des Objets (WSdO), un domaine de recherche à l'interface de l'Internet des Objets (IdO) et du Web Sémantique (WS). L’intégration des approche du WS à l'IdO permettent de traiter l'importante hétérogénéité des ressources, des technologies et des applications de l'IdO, laquelle est une source de problèmes d'interopérabilité freinant le déploiement de systèmes IdO. Un premier verrou scientifique est lié à la consommation en ressource des technologies du WS, là où l'IdO s’appuie sur des objets aux capacités de calcul et de communication limitées. De plus, les réseaux IdO sont déployés à grande échelle, quand la montée en charge est difficile pour les technologies du WS. Cette thèse a pour objectif de traiter ce double défi, et comporte deux contributions. La première porte sur l'identification de critères de qualité pour les ontologies de l'IdO, et l’élaboration de IoT-O, une ontologie modulaire pour l'IdO. IoT-O a été implantée pour enrichir les données d'un bâtiment instrumenté, et pour être moteur de semIoTics, notre application de gestion autonomique. La seconde contribution est EDR (Emergent Distributed Reasoning), une approche générique pour distribuer dynamiquement le raisonnement à base de règles. Les règles sont propagées de proche en proche en s'appuyant sur les descriptions échangées entre noeuds. EDR est évaluée dans deux scénario concrets, s'appuyant sur un serveur et des noeuds contraints pour simuler le déploiement. / This thesis is situated in the Semantic Web of things (SWoT) domain, at the interface between the Internet of Things (IoT) and the Semantic Web (SW). The integration of SW approaches into the IoT aim at tackling the important heterogeneity of resources, technologies and applications in the IoT, which creates interoperability issues impeding the deployment of IoT systems. A first scientific challenge is risen by the resource consumption of the SW technologies, inadequated to the limites computation and communication capabilities of IoT devices. Moreover, IoT networks are deployed at a large scale, when SW technologies have scalability issues. This thesis addresses this double challenge by two contributions. The first one is the identification of quality criteria for IoT ontologies, leading to the proposition of IoT-O, a modular IoT ontology. IoT-O is deployed to enrich data from a smart building, and drive semIoTics, our autonomic computing application. The second contribution is EDR (Emergent Distributed Reasoning), a generic approach to dynamically distributed rule-based reasoning. Rules are propagated peer-to-peer, guided by descriptions exchanged among nodes. EDR is evaluated in two use-cases, using both a server and some constrained nodes to simulate the deployment.

<p>A difficult issue in stress management is to use biomedical sensor signal in the diagnosis and treatment of stress. Clinicians often make their diagnosis and decision based on manual inspection of physiological signals such as, ECG, heart rate, finger temperature etc. However, the complexity associated with manual analysis and interpretation of the signals makes it difficult even for experienced clinicians. Today the diagnosis and decision is largely dependent on how experienced the clinician is interpreting the measurements.  A computer-aided decision support system for diagnosis and treatment of stress would enable a more objective and consistent diagnosis and decisions.</p><p>A challenge in the field of medicine is the accuracy of the system, it is essential that the clinician is able to judge the accuracy of the suggested solutions. Case-based reasoning systems for medical applications are increasingly multi-purpose and multi-modal, using a variety of different methods and techniques to meet the challenges of the medical domain. This research work covers the development of an intelligent clinical decision support system for diagnosis, classification and treatment in stress management. The system uses a finger temperature sensor and the variation in the finger temperature is one of the key features in the system. Several artificial intelligence techniques have been investigated to enable a more reliable and efficient diagnosis and treatment of stress such as case-based reasoning, textual information retrieval, rule-based reasoning, and fuzzy logic. Functionalities and the performance of the system have been validated by implementing a research prototype based on close collaboration with an expert in stress. The case base of the implemented system has been initiated with 53 reference cases classified by an experienced clinician. A case study also shows that the system provides results close to a human expert. The experimental results suggest that such a system is valuable both for less experienced clinicians and for experts where the system may function as a second option.</p> / IPOS, PROEK

A difficult issue in stress management is to use biomedical sensor signal in the diagnosis and treatment of stress. Clinicians often make their diagnosis and decision based on manual inspection of physiological signals such as, ECG, heart rate, finger temperature etc. However, the complexity associated with manual analysis and interpretation of the signals makes it difficult even for experienced clinicians. Today the diagnosis and decision is largely dependent on how experienced the clinician is interpreting the measurements.  A computer-aided decision support system for diagnosis and treatment of stress would enable a more objective and consistent diagnosis and decisions. A challenge in the field of medicine is the accuracy of the system, it is essential that the clinician is able to judge the accuracy of the suggested solutions. Case-based reasoning systems for medical applications are increasingly multi-purpose and multi-modal, using a variety of different methods and techniques to meet the challenges of the medical domain. This research work covers the development of an intelligent clinical decision support system for diagnosis, classification and treatment in stress management. The system uses a finger temperature sensor and the variation in the finger temperature is one of the key features in the system. Several artificial intelligence techniques have been investigated to enable a more reliable and efficient diagnosis and treatment of stress such as case-based reasoning, textual information retrieval, rule-based reasoning, and fuzzy logic. Functionalities and the performance of the system have been validated by implementing a research prototype based on close collaboration with an expert in stress. The case base of the implemented system has been initiated with 53 reference cases classified by an experienced clinician. A case study also shows that the system provides results close to a human expert. The experimental results suggest that such a system is valuable both for less experienced clinicians and for experts where the system may function as a second option. / IPOS, PROEK

Afin d'accompagner les professionnels de santé dans leur démarche clinique, plusieurs systèmes de suivi et deprise en charge médicale ont été construits et déployés dans le milieu hospitalier. Ces systèmes permettentprincipalement de collecter des données médicales sur les patients, de les analyser et de présenter les résultats dedifférentes manières. Ils représentent un appui et une aide aux professionnels de santé dans leur prise de décisionpar rapport à l'évolution de l'état de santé des patients suivis. L'utilisation de tels systèmes nécessitesystématiquement une adaptation à la fois au domaine médical concerné et au mode d'intervention. Il estnécessaire, dans un milieu hospitalier, que ces systèmes puissent s'adapter et évoluer d'une manière simple, enlimitant toute maintenance corrective ou évolutive. Ils doivent être en mesure de prendre en compte dynamiquementdes connaissances théoriques et empiriques du domaine issues des experts médicaux.Afin de répondre à ces exigences, nous avons proposé une approche pour la construction d'un système d'aide à ladécision médicale capable de s'adapter au domaine médical concerné et au mode d'intervention approprié pourassister les professionnels de santé dans leur démarche clinique. Cette approche permet notamment l'organisationde la collecte des données médicales, en tenant compte du contexte du patient, la représentation desconnaissances du domaine à base d'ontologies ainsi que leur exploitation associée aux guides de bonnes pratiqueset à l'expérience clinique.Dans la continuité des travaux précédemment réalisés au sein de notre équipe de recherche, nous avons choisid'enrichir, avec notre approche, la plateforme E-care qui est dédiée au suivi et à la détection précoce de touteanomalie de l'état de patients atteints de maladies chroniques. Nous avons pu ainsi adapter facilement la plateformeE-care aux différentes expérimentations qui sont été menées notamment dans des EPHAD de la MutualitéFrançaise en Anjou-Mayenne, au CHU de Hautepierre et au CHUV à Lausanne.Les résultats de ces expérimentations ont montré l'efficacité de l'approche proposée. L'adaptation de la plateformepar rapport au domaine et au mode d'intervention de chacune de ces expérimentations se limite à de la simpleconfiguration. De plus, l'approche proposée a suscité l'intérêt du personnel médical par rapport à l'organisation de lacollecte des données, qui tient compte du contexte du patient, et par rapport à l'exploitation des connaissancesmédicales qui apporte aux professionnels de santé une assistance pour une meilleure prise de décision. / To support health professionals in their clinical processes, several monitoring and medical care systems have beenbuilt and deployed in the hospital setting. These systems are mainly used to collect medical data on patients,analyze and present the outcomes in different ways. They represent support and assistance to health professionalsin their decision making regarding the evolution in the health status of the patients followed. The use of suchsystems always requires an adaptation to both the medical field and the mode of intervention. It is necessary, in ahospital setting, to adapt and evolve these systems in a simple manner, limiting any corrective or evolutionarymaintenance. Moreover, these systems should be able to consider dynamically the domain knowledge from medicalexperts.To meet these requirements, we proposed an approach for the construction of a medical decision support system(MDSS). This MDSS can adapt to the medical field and to the appropriate mode of intervention to assist healthprofessionals in their clinical processes. This approach allows especially the organization of the medical datacollection by taking into account the patient¿s context, the ontology-based knowledge representation of the domainand permits the exploitation of the medical guidelines and the clinical experience.In continuity of our research team¿s previous work, we chose to expand with our approach, the E-care platformwhich is dedicated to monitoring and early detection of any abnormality of the health status of patients with chronicdiseases. We were able to adapt easily the E-care platform for the various experiments that have been conducted,including EPHAD of the Mutualité Française in Anjou-Mayenne, Hautepierre hospital and Lausanne hospital(CHUV).The outcomes of these experiments have shown the effectiveness of the proposed approach. Where, the adaptationof the platform regarding to the domain and mode of intervention of each of these experiments is limited to thesimple configuration. Furthermore, the proposed approach has attracted the interest of the medical staff regardingthe organization of the medical data collection, and the exploitation of the medical knowledge which bringsassistance to the health professionals for better decision making.

Les médecins cherchent à résoudre les problèmes de santé posés par des individus. Une solution individualisée tient compte de la singularité du patient concerné. L'individualisation des pratiques est-elle possible et souhaitable? Le cas échéant, selon quelles modalités peut-elle ou doit-elle être réalisée'? La première partie de la thèse vise à montrer: que la question se pose depuis les premières théories de la décision médicale (Hippocrate) ; qu'elle s'est posée de façon aiguë au début du XIX" siècle, avec l'apparition des études statistiques; et que l'observation médicale et son évolution concrétisent la façon dont la documentation des cas et leur individualisation interagissent. La deuxième partie reprend la question dans le contexte contemporain, à travers la naissance de l'"evidence-based medicine", ses critiques et son évolution. La troisième partie montre que l'articulation du raisonnement par règles et du raisonnement par cas modélise de façon opérationnelle une démarche raisonnée d'individualisation des décisions médicales. Ce modèle simple permet de rendre compte du mouvement d'aller-retour entre deux conceptions de l'individualisation et d'en proposer une version équilibrée, mise à l'épreuve dans les domaines de l'évaluation des pratiques et de la littérature médicale. / Physicians try to solve health problems of individual patients. Customized solutions take into account the uniqueness of the patient. Is the individualization of medical decisions possible and desirable'? If so, how can I tor should it be performed? The first part of the thesis shows: that the question arises since the first conceptualizations of medical reasoning (Hippocrates); that is was much debated in the early nineteenth century, when statistical studies were first performed to guide medical decisions; and that the medical observation and its evolution materialize how case documentation and management interact. The second part addresses the issue in the current context, from the birth of evidence-based medicine, its cri tics and its evolution. The third part shows that linking rule-based and case-based reasoning adequately pictures the process of customizing medical decisions. This simple model can account for the movement between two kinds of customization and leads to a balanced approach, tested in the field of practice evaluation and medical literature.

Le développement et l’usage croissants de systèmes pervasifs, dotés de fonctionnalités et de moyens de communication de plus en plus sophistiqués, offrent de fantastiques potentialités de services, en particulier pour l’e-Santé et la télémédecine, au bénéfice de tout citoyen, patient ou professionnel de santé. L’un des challenges sociétaux actuels est de permettre une meilleure exploitation des services disponibles pour l’ensemble des acteurs impliqués dans un domaine donné. Mais la multiplicité des services offerts, la diversité fonctionnelle des systèmes, et l’hétérogénéité des besoins nécessitent l’élaboration de modèles de connaissances de ces services, des fonctions de ces systèmes et des besoins. En outre, l’hétérogénéité des environnements informatiques distribués, la disponibilité et les capacités potentielles des diverses ressources humaines et matérielles (instrumentation, services, sources de données, etc.) requises par les différentes tâches et processus, la variété des services qui fournissent des données aux utilisateurs, et les conflits d’interopérabilité entre schémas et sources de données sont autant de problématiques que nous avons à considérer au cours de nos travaux de recherche. Notre contribution vise à optimiser la qualité de services en environnement ambiant et à réaliser une exploitation intelligente de ressources ubiquitaires. Pour cela, nous proposons un méta-modèle de connaissances des principaux concepts à prendre en compte en environnement pervasif. Ce méta-modèle est basé sur des ontologies décrivant les différentes entités précitées dans un domaine donné ainsi que leurs relations. Puis, nous l’avons formalisé en utilisant un langage standard de description des connaissances. A partir de ce modèle, nous proposons alors une nouvelle méthodologie de construction d’un framework architectural, que nous avons appelé ONOF-PAS. ONOF-PAS est basé sur des modèles ontologiques, une base de règles, un moteur d’inférence, et des composants orientés objet permettant la gestion des différentes tâches et le traitement des ressources. Il s’agit d’une architecture générique, applicable à différents domaines. ONOF-PAS a la capacité d’effectuer un raisonnement à base de règles pour gérer les différents contextes d’utilisation et aider à la prise de décision dans des environnements hétérogènes dynamiques, tout en tenant compte de la disponibilité et de la capacité des ressources humaines et matérielles requises par les diverses tâches et processus exécutés par des systèmes d’information pervasifs. Enfin, nous avons instancié ONOF-PAS dans le domaine de la télémédecine pour traiter le scénario de l’orientation des patients ou de personnes victimes de problèmes de santé en environnement hostile telles que la haute montagne ou des zones géographiquement isolées. Un prototype d’implémentation de ces scénarios, appelé T-TROIE a été développé afin de valider le framework ONOF-PAS. / The growing development and use of pervasive systems, equipped with increasingly sophisticated functionalities and communication means, offer fantastic potentialities of services, particularly in the eHealth and Telemedicine domains, for the benifit of each citizen, patient or healthcare professional. One of the current societal challenges is to enable a better exploitation of the available services for all actors involved in a given domain. Nevertheless, the multiplicity of the offered services, the systems functional variety, and the heterogeneity of the needs require the development of knowledge models of these services, systems functions, and needs. In addition, the distributed computing environments heterogeneity, the availability and potential capabilities of various human and material resources (devices, services, data sources, etc.) required by the different tasks and processes, the variety of services providing users with data, the interoperability conflicts between schemas and data sources are all issues that we have to consider in our research works. Our contribution aims to empower the intelligent exploitation of ubiquitous resources and to optimize the quality of service in ambient environment. For this, we propose a knowledge meta-model of the main concepts of a pervasive environment, such as Actor, Task, Resource, Object, Service, Location, Organization, etc. This knowledge meta-model is based on ontologies describing the different aforementioned entities from a given domain and their interrelationships. We have then formalized it by using a standard language for knowledge description. After that, we have designed an architectural framework called ONOF-PAS (ONtology Oriented Framework for Pervasive Applications and Services) mainly based on ontological models, a set of rules, an inference engine, and object oriented components for tasks management and resources processing. Being generic, extensible, and applicable in different domains, ONOF-PAS has the ability to perform rule-based reasoning to handle various contexts of use and enable decision making in dynamic and heterogeneous environments while taking into account the availability and capabilities of the human and material resources required by the multiples tasks and processes executed by pervasive systems. Finally, we have instantiated ONOF-PAS in the telemedicine domain to handle the scenario of the transfer of persons victim of health problems during their presence in hostile environments such as high mountains resorts or geographically isolated areas. A prototype implementing this scenario, called T-TROIE (Telemedicine Tasks and Resources Ontologies for Inimical Environments), has been developed to validate our approach and the proposed ONOF-PAS framework.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-15T14:16:38Z No. of bitstreams: 1 ALEXANDRE NÓBREGA DUARTE - DISSERTAÇÃO PPGCC 2003..pdf: 1526817 bytes, checksum: dfc39cd8b1649bf64468cbe2eaefe99b (MD5) / Made available in DSpace on 2018-08-15T14:16:38Z (GMT). No. of bitstreams: 1 ALEXANDRE NÓBREGA DUARTE - DISSERTAÇÃO PPGCC 2003..pdf: 1526817 bytes, checksum: dfc39cd8b1649bf64468cbe2eaefe99b (MD5) Previous issue date: 2003-02-25 / Apresenta uma nova ferramenta para o diagnóstico automático de falhas em redes elétricas. A ferramenta utiliza uma técnica híbrida de correlação de eventos criada especialmente para ser utilizada em redes com constantes modificações de topologia. A técnica híbrida combina o raciocínio baseado em regras com o raciocínio baseado em modelos para eliminar as principais limitações do raciocínio baseado em regras. Com a ferramenta de diagnóstico foi possível validar o conhecimento dos especialistas em sistemas de transmissão de energia elétrica necessário para o diagnóstico de falhas em linhas de transmissão e construir uma base de regras para tal. A ferramenta foi testada no diagnóstico de falhas em linhas de transmissão de um dos cinco centros regionais da Companhia Hidro Elétrica do São Francisco (CHESF) e apresentou resultados satisfatórios de desempenho e precisão. / It presents a new tool for the automatic diagnosis of faults in electric networks. The toot uses a hybrid event correlation technique especially created to be used in networks with constant topological modifications. The hybrid technique combines ruJe-based reasoning with modelbased reasoning to eliminate the main limitations of rule-based reasoning. With the tool it was possible to validate the knowledge acquired from electric energy transmission systems specialists needed for the diagnosis of faults in transmission lines and to construct rules. The tool was tested in the diagnosis of faults in transmission lines of one of the five regional centers of the Companhia Hidro Elétrica do São Francisco (CHESF) and presented satisfactoiy results in terms of performance and precision.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-08-16T13:58:48Z No. of bitstreams: 1 STEFANI SILVA PIRES - DISSERTAÇÃO PGCC 2010..pdf: 819684 bytes, checksum: 625f468cb174d699bf5b98131d1adf61 (MD5) / Made available in DSpace on 2018-08-16T13:58:48Z (GMT). No. of bitstreams: 1 STEFANI SILVA PIRES - DISSERTAÇÃO PGCC 2010..pdf: 819684 bytes, checksum: 625f468cb174d699bf5b98131d1adf61 (MD5) Previous issue date: 2010-08-19 / Este trabalho apresenta uma técnica de análise de causa-raiz para sistemas elétricos de potência. A análise de causa-raiz é uma forma de auxiliar o operador na compreensão da ocorrênciadefalha,interpretandoasocorrênciascomefeito"cascata"entreoselementosda rede. A técnica proposta utiliza o raciocínio baseado em regras, onde regras parametrizadas constroem um modelo de propagação com os diagnósticos de uma ocorrência de falha. A técnica permite apontar o elemento causador da ocorrência, e detalhar a sua propagação para os demais elementos em um modelo de causa-efeito. A utilização de regras parametrizadas traz grandes vantagens ao processo, permitindo que a técnica seja adaptável a alterações na topologia do sistema, e contribuindo para sua escalabilidade. Um estudo de caso foi elaborado para sua avaliação, no contexto da Companhia Hidro Elétrica do São Francisco (CHESF), onde foi desenvolvido um protótipo que implementa a técnica, e levantados um conjunto de regras parametrizadas e um conjunto de cenários de falha utilizando uma ferramenta de simulação de um ambiente real, o Simulop. Utilizamos também na avaliação, um conjunto de regressões, que são dados históricos armazenados pela CHESF. As regressões foramimportantesnaprimeirafasededefiniçãodatécnica,masapresentamproblemascomo afaltadedados,ecomportamentosinesperadosdosistema,ondeamargemdeacertodatécnica foi de 74%. Para o conjunto de cenários levantados com oSimulop, a técnica proposta conseguiu realizar com sucesso o processo de análise de causa-raiz, identificando a causaraiz da ocorrência em 100% dos cenários de falha, e detalhando sua propagação para todos os outros elementos da rede envolvidos em 89% dos cenários, onde a margem de erro é composta de cenários cuja propagação foi identificada apenas parcialmente, devido à falta de regras que contemplassem os cenários. Dessa forma, a técnica proposta se mostrou uma abordagem viável para a análise de causa-raiz em sistemas elétricos. A margem de acerto reduzida nas regressões, indica que, para ser aplicada em um ambiente operacional real, faz-se necessária a elaboração de um conjunto de regras mais abrangente e que possa contornar esses problemas. / This paper presents a root cause analysis technique for electric power systems. The root cause analysis is a way to assist the operator in understanding the occurrence of failure, interpreting the events cascade occurrences. The proposed technique uses a rule based reasoning, where parameterized rules construct a propagation model with diagnosis of an occurrence of failure. The technique allows to point out the element that causes the occurrence, and detailing its propagation to other elements in a cause and effect model. The use of parameterized rules brings major benefits to the process, allowing the technique to be adaptable to changes in system topology, and contributing to its scalability A case study was prepared for evaluation in the context of the Companhia Hidro Elétrica do São Francisco (CHESF). We developed a prototype that implements the technique, and raised a set of parameterized rules and a set of failure scenarios using a tool to simulate a real environment, the Simulop. We also used in the evaluation process, a set of regressions, which are historical data stored by CHESF. The regressions were important in the first phase of the technique, but they have problems such as lack of data, and unexpected behavior of the system, where the accuracy of the technique was 74%. For the set of scenarios created with Simulop, the proposed technique has achieved success in the root cause analysis process, identifying the root cause of the occurrence in 100% of failure scenarios, and detailing their propagation to all other equipments involved in 89% of scenarios, where the margin of error is composed of scenarios whose propagation has been identified only in part due to the lack of rules that contemplate these scenarios. Thus, the proposed technique proved to be a viable approach to root cause analysis in electrical systems. The reduced margin of success in the regressions , indicates that, to be applied to an operational environment, it is necessary to elaborate a comprehensive set of rules that can deal these problems.