L’augmentation de la fréquence et de l’intensité des événements de grande ampleur est unanime. En France, l’État impose à l’échelle communale, de se préparer à de tels événements en établissant un Plan Communal de Sauvegarde. Cependant les instances décisionnaires à ce niveau ne disposent pas d’outils leurs permettant au préalable de connaitre la capacité de fonctionnement de leur organisation. Ces travaux de recherche proposent une méthode d’évaluation a priori de l’organisation locale d’urgence pour permettre aux instances décisionnaires, d’identifier des points vulnérables dans leur organisation et ainsi leur fournir une aide à la décision. Cette méthode d’évaluation repose sur le formalisme d’une méthode de modélisation établie, permettant d’une part d’appréhender la complexité des éléments mis en jeux dans l’organisation de gestion d’événements et d’autre part sert de base pour les mécanismes d’évaluation. Ces derniers sont quant à eux supportés par le formalisme des arbres de défaillance. Cependant, ce formalisme est limitant, car il ne propose qu’une évaluation de la défaillance à deux états discrets (complètement nulle ou complètement avérée). C’est pourquoi, ces travaux se sont intéressés à la conception d’une méthode d’évaluation à base d’arbre de défaillance multi-États. Cela se traduit par une nouvelle définition des événements et des portes pour les arbres utilisés dans la méthode de modélisation retenue. Un questionnaire a été créé pour collecter auprès des gestionnaires, les informations sur les états de défaillance. Les résultats de l’évaluation sont présentés sous forme de tableaux de bord et permettent ainsi de guider le choix des actions d’amélioration. / The increase in frequency and intensity of major disasters make a consensus. In France, the state imposes to local administrations to be prepared to face such events by describing their local organizations in a Local Emergency Response Plan (LERP). However, there are no existing tools for decision-Makers at this authority scale to a priori assess functioning capacity of the organization described in their plans. This research work proposes an a priori assessment method of Local Emergency Response Plans, to allow local authorities to identify organizational vulnerabilities of their plans, and thus giving to them an aid to decision-Making. This assessment method is laid on an established formalism of modelling methods. This allows, in one hand, to catch the complexity of elements’ stakes in emergency management and in another hand to lay assessment mechanisms for this one. These mechanisms are supported by Fault-Tree formalism. However, this is restricting because the failure of modelled elements can only be assessed on two discrete levels: complete functioning or complete dysfunctioning. This is why this work aims to build an assessment method based on Multi-Level Fault-Tree. This means that new gates have to be described according to the assessed object (LERP). Furthermore, modelled elements have to be improved to take into account Multi-Level considerations in the chosen modelling method. According to that, a questionnaire has been developed to collect information from local authorities about failure states of modelled elements. The results of this assessment are presented in a dashboard format. The purpose is first, to guide local authorities by having a quick overview of the overall organization system represented in the LERP. Secondly, it helps them to plan the vulnerabilities reductions in a management program.

Made available in DSpace on 2014-12-17T14:56:21Z (GMT). No. of bitstreams: 1 DanielECRM_DISSERT.pdf: 8738315 bytes, checksum: d256cff68e3707ec5352efefd60cc545 (MD5) Previous issue date: 2014-07-04 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / There is a growing need to develop new tools to help end users in tasks related to the design, monitoring, maintenance and commissioning of critical infrastructures. The complexity of the industrial environment, for example, requires that these tools have flexible features in order to provide valuable data for the designers at the design phases. Furthermore, it is known that industrial processes have stringent requirements for dependability, since failures can cause economic losses, environmental damages and danger to people. The lack of tools that enable the evaluation of faults in critical infrastructures could mitigate these problems. Accordingly, the said work presents developing a framework for analyzing of dependability for critical infrastructures. The proposal allows the modeling of critical infrastructure, mapping its components to a Fault Tree. Then the mathematical model generated is used for dependability analysis of infrastructure, relying on the equipment and its interconnections failures. Finally, typical scenarios of industrial environments are used to validate the proposal / A demanda para o desenvolvimento de novas ferramentas que facilitem o projeto, monitoramento, manuten??o e comissionamento de infraestruturas cr?ticas ? permanente. A complexidade do ambiente industrial, por exemplo, exige que estas ferramentas apresentem funcionalidades bastante flex?veis, informando dados valiosos para os projetistas ainda na fase de pr?-projeto. Adicionado a estes fatores, sabe-se que os processos industriais apresentam requisitos de dependabilidade r?gidos, uma vez que falhas podem provocar perdas econ?micas, danos ambientais e riscos de vida aos oper?rios. A utiliza??o de uma ferramenta que habilite a avalia??o de falhas nas infraestruturas cr?ticas poderia mitigar esses problemas. Nesse sentido, o referido trabalho apresenta o desenvolvimento de uma framework para an?lise da dependabilidade de infraestruturas cr?ticas. A proposta permite a modelagem das infraestruturas cr?ticas, mapeando seus componentes em uma ?rvore de Falha. Em seguida, o modelo matem?tico gerado ? utilizado para an?lise da dependabilidade da infraestrutura, baseando-se nas falhas de equipamentos e suas interliga??es. Finalmente, cen?rios t?picos de ambientes industriais s?o utilizados para a valida??o da proposta

Made available in DSpace on 2014-10-09T12:27:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:51Z (GMT). No. of bitstreams: 0 / Neste trabalho é aplicada a metodologia da Análise Probabilística de Segurança nível 1 ao reator IEA-R1. Inicialmente são descritos os eventos iniciadores de acidentes identificados no reator para duas categorias: perda de vazão e perda de refrigerante primário. Dentre eles foram escolhidos dois eventos iniciadores para análise mais detalhada do acidente e obtenção da estimativa da freqüência de danos ao núcleo devido a sua ocorrência. Foram selecionados os seguintes eventos iniciadores: bloqueio de canal de refrigeração (maior probabilidade) e perda de refrigerante por grande ruptura da tubulação do circuito primário (maiores consequências). Para modelar a evolução do acidente a partir da ocorrência do evento iniciador e da atuação ou não dos sistemas de segurança utilizou-se Árvore de Eventos. Através de Árvore de Falhas, também foi avaliada a confiabilidade dos seguintes sistemas: sistema de desligamento do reator, isolamento da piscina, sistema de resfriamento de emergência (SRE) e sistema elétrico. Como resultados foram obtidas as estimativas das frequências de danos ao núcleo do reator e as probabilidades de falha dos sistemas analisados. As freqüências de danos ao núcleo mostraram-se dentro das margens esperadas, sendo da mesma ordem de grandeza que os encontrados para reatores similares. As confiabilidades dos sistemas de desligamento do reator, de isolamento da piscina e do SRE foram satisfatórias para as condições em que estes sistemas foram exigidos. Todavia, para o sistema elétrico seria recomendável uma análise para verificar a possibilidade de modernização a fim de aumentar a sua confiabilidade. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2016-11-11T09:45:23Z No. of bitstreams: 0 / Made available in DSpace on 2016-11-11T09:45:23Z (GMT). No. of bitstreams: 0 / Um desafio recorrente em processos produtivos é o desenvolvimento de sistemas de monitoração e diagnóstico. Esses sistemas ajudam na detecção de mudanças inesperadas e interrupções, prevenindo perdas e mitigando riscos. Redes Neurais Artificiais (RNA) têm sido largamente utilizadas na criação de sistemas de monitoração. Normalmente as RNA utilizadas para resolver este tipo de problema são criadas levando-se em conta apenas parâmetros como o número de entradas, saídas e quantidade de neurônios nas camadas escondidas. Assim, as redes resultantes geralmente possuem uma configuração onde há uma total conexão entre os neurônios de uma camada e os da camada seguinte, sem que haja melhorias em sua topologia. Este trabalho utiliza o algoritmo de Otimização por Colônia de Formigas (OCF) para criar redes neurais otimizadas. O algoritmo de busca OCF utiliza a técnica de retropropagação de erros para otimizar a topologia da rede neural sugerindo as melhores conexões entre os neurônios. A RNA resultante foi aplicada para monitorar variáveis do reator de pesquisas IEA-R1 do IPEN. Os resultados obtidos mostram que o algoritmo desenvolvido é capaz de melhorar o desempenho do modelo que estima o valor de variáveis do reator. Em testes com diferentes números de neurônios na camada escondida, utilizando como comparativos o erro quadrático médio, o erro absoluto médio e o coeficiente de correlação, o desempenho da RNA otimizada foi igual ou superior ao da tradicional. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

European Commission (2011) aims to reduce the greenhouse gas emission sby 85-95% by 2050 in comparison to 1990’s levels. Wave energy could be an important step to archiving this goal. This report aims to develop a quantitative risk assessment for the Uppsala University's wave energy converter. Failure rates have been collected from various databases and reports and have been processed accordingly in order to implement them in the risk analysis. CAPEX, OPEX and possible downtime windows have been estimated. A fault tree analysis (FTA) has estimated the total unavailability, unreliability and downtime. Furthermore an economical assessment model using Monte Carlo and the unreliability data from the FTA has been developed, estimating the expected LCOE and OPEX/WEC for parks consisting of 20, 100, and 200 WECs (wave energy converters). The result show that the O-ring seal has the largest impact on both the unavailability, and the economy of the OPEX/WEC. Second biggest contributor is the translator bearing failure. The study also shows that the CAPEX cost has to be reduced to make the LCOE competitive in comparison to other renewable sources. A comparison between the system unavailability and unreliability has also been done in terms of different component parameters.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-17T19:47:15Z No. of bitstreams: 1 fabricioluisdeandrade.pdf: 7057434 bytes, checksum: a55af7d732de984b9bfdfca483496632 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T15:12:38Z (GMT) No. of bitstreams: 1 fabricioluisdeandrade.pdf: 7057434 bytes, checksum: a55af7d732de984b9bfdfca483496632 (MD5) / Made available in DSpace on 2016-01-25T15:12:38Z (GMT). No. of bitstreams: 1 fabricioluisdeandrade.pdf: 7057434 bytes, checksum: a55af7d732de984b9bfdfca483496632 (MD5) Previous issue date: 2015-08-04 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Esta pesquisa teve como objetivo identificar e detalhar pontos com risco para movimentos de massa - na tipologia movimento de blocos rochosos - na área tombada do Morro do Cristo em Juiz de Fora, MG, bem como a percepção deste risco por parte da população residente nas áreas consideradas mais vulneráveis junto ao sopé da mesma. O estudo foi desenvolvido na porção compreendida pelo polígono estabelecido pelas ruas Espírito Santo e São Sebastião, sentido N-S e pela vertente tombada do Morro do Cristo e a Av. Olegário Maciel, sentido WE. O estudo foi dividido em quatro etapas: na primeira etapa buscou-se identificar e avaliar a estabilidade dos blocos de rocha com dimensões iguais ou superiores a 100x100x100cm. Para tanto, foi utilizada a ficha de avaliação de estabilidade de blocos rochosos (BRASIL, 2011). Na segunda etapa identificou-se as tipologias dos movimentos dos blocos classificados como instáveis e muito instáveis (INFANTI e FORNASARI, 1998). Na terceira etapa verificou-se a percepção de risco que os moradores das áreas mais vulneráveis possuem, por meio de entrevistas semi-estruturadas, que foram transcritas e tiveram seu conteúdo analisado conforme Bardin (1977). Na quarta e última etapa foram elaboradas uma árvore de falhas e um diagrama de causa e consequência (ROCHA, 2005). Um total de trinta (30) blocos foram identificados e avaliados, sendo que destes, três (3) se encontravam instáveis e dez (10) muito instáveis. As quedas e rolamentos mostraram-se como os movimentos comuns no local. Os resultados das entrevistas revelaram uma baixa percepção do risco por parte dos moradores. Consequências naturais e/ou antrópicas são as causas possíveis para as quedas e/ou rolamentos de blocos de rocha. As medidas para a redução da instabilidade dos blocos de rocha e conseqüente redução do risco no local consistem em intervenções de responsabilidade do poder público. A partir desses dados é possível apontar a condição de alto risco para movimento de blocos de rocha na área de estudo. / This research had as its objective to identify and detail risky points for mass movements – in the rock block movement typology – in the protected area of Morro do Cristo in Juiz de Fora, MG, as well as the perception of this risk by part of the population residing in the areas considered to be more vulnerable by its foothills. The study was developed in the part surrounded by the polygon made by the streets Espírito Santo and São Sebastião, running N-S and by the protected slope of Morro do Cristo and Av. Olegário Maciel, running W-E. the study was divided in four stages: on the first stage we sought to identify and evaluate the stability of the rock blocks with dimensions of or above 100x100x100cm. For that we used the rock block stabilization evaluation form (BRASIL, 2011). On the second stage we identified the movement typology of the blocks classified as unstable and very unstable (INFANTI and FORNASARI, 1998). On the third stage we elaborated a tree of faults and a diagram of cause and effect (ROCHA, 2005). On the fourth and last stage we verified the perception of risk that the residents of the more vulnerable areas suffer by means of semistructured interview, which were transcribed and had their content analyzed according to Bardin (1977). A total of thirty (30) were identified and evaluated, out of them, three (3) were found unstable and ten (10) very unstable. The falls and rolls presented themselves as common movements in the place. The results of the interviews revealed a low perception of risk by part of the residents. Natural and/or man-made consequences are the possible causes for the falls and/or rolls of rock blocks. The measures for the reduction of the instability of the rock blocks and consequent reduction of risk in the place are interventions liable to the public authorities. From this data it is possible to point out a high-risk condition for the rock block movements in the studied area.

Component failures can result in catastrophic behaviors in safety critical embedded systems, sometimes resulting in loss of life. Component failures can be treated as off nominal behaviors (ONBs) with respect to the components and sub systems involved in an embedded system. A lot of research is being carried out to tackle the problem of ONBs. These approaches are mainly focused on the states (i.e., desired and undesired states of a system at a given point of time to detect ONBs). In this paper, an approach is discussed to detect component failures and critical components of an embedded system. The approach is based on fault tree analysis (FTA), applied to the requirements specification of embedded systems at design time to find out the relationship between individual component failures and overall system failure. FTA helps in determining both qualitative and quantitative relationship between component failures and system failure. Analyzing the system at design time helps in detecting component failures and critical components and helps in devising strategies to mitigate component failures at design time and improve overall safety and reliability of a system.

This thesis focuses on the theoretical description of risk management options related to information technologies and describes methods used to risk analysis. Described methods are fault tree analysis, event tree analysis, FMEA, HAZOP and Markovov analysis. Practical part includes proposal and implementation of program that visualizes decision trees and determines probability of each tree item.

This thesis deals with the sludge management in wastewater treatment plants. It provides a basic overview of methods for modifying risk material in sludge ending. The main goal of this work is to create a fault trees based on faults which occurred in the sludge management facilities. Furthermore, it was created frequency of failures assessment of the objects on wastewater treatment plant in Hodonín. Provided information were obtained during excursions of WWTP Hodonín and Zbýšov.

Yes / Dynamic systems exhibit time-dependent behaviours and complex functional dependencies amongst their components. Therefore, to capture the full system failure behaviour, it is not enough to simply determine the consequences of different combinations of failure events: it is also necessary to understand the order in which they fail. Pandora temporal fault trees (TFTs) increase the expressive power of fault trees and allow modelling of sequence-dependent failure behaviour of systems. However, like classical fault tree analysis, TFT analysis requires a lot of manual effort, which makes it time consuming and expensive. This in turn makes it less viable for use in modern, iterated system design processes, which requires a quicker turnaround and consistency across evolutions. In this paper, we propose for a model-based analysis of temporal fault trees via HiP-HOPS, which is a state-of-the-art model-based dependability analysis method supported by tools that largely automate analysis and optimisation of systems. The proposal extends HiP-HOPS with Pandora, Petri Nets and Bayesian Networks and results to dynamic dependability analysis that is more readily integrated into modern design processes. The effectiveness is demonstrated via application to an aircraft fuel distribution system. / Partly funded by the DEIS H2020 project (Grant Agreement 732242).