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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.
11

Análise de substituição de ativos com base em variáveis de confiabilidade e sustentabilidade: uma aplicação DEA / Asset replacement analysis based on reliability and sustainability variables: an DEA application

Roiz, Guilherme Augusto 14 March 2016 (has links)
As companhias estão inseridas em um contexto global de preocupação sustentável, onde questões ambientais e sociais acompanham as preocupações econômicas. Faz-se necessário englobar, de alguma forma, nas análises de viabilidade econômica ou ainda em modelagens de Vida Econômica e Reposição de Ativos, variáveis que possam representar aspectos sociais e ambientais. Nesse panorama entra a norma PAS-55 - Publicly Avaiable Specification - 55, publicada pela British Standards Institution, que visa aperfeiçoar o sistema de gestão de ativos físicos de maneira a permitir maiores resultados econômicos, sociais e ambientais, provenientes da utilização dos equipamentos, nas empresas. Os procedimentos previstos na norma PAS-55 sugerem o alinhamento de conhecimentos oriundos da gestão de manutenção, que compõem o arcabouço da Engenharia de Confiabilidade, a conhecimentos de Engenharia Econômica, de maneira a compor ferramentas e métodos para tomar decisões em relação aos ativos físicos de empresas. O objetivo do presente trabalho é propor um modelo de substituição de ativos que considere variáveis de Confiabilidade e Sustentabilidade, juntamente com variáveis financeiras, por meio da Análise Envoltória de Dados. Os resultados apresentam um modelo conceitual de substituição de ativos, com inclusão de variáveis socioambientais e aplicação DEA e, também, um estudo de caso com dados reais que avalia a substituição de um equipamento pertencente a uma empresa produtora de ácido fosfórico. / Companies are placed in a global context of sustainable concern where environmental and social issues accompanying economic concerns. It is necessary to include, in some way, the economic feasibility analysis or in modeling of Economic Life and Asset Replacement, variables that may pose social and environmental aspects. In this scenario enters the PAS-55 standard - Publicly Avaiable Specification - 55, published by the British Standards Institution, which aims to improve the management system of physical assets in order to allow greater economic results, social and environmental issues arising from the use of equipment, in companies. The procedures laid down in PAS-55 standard suggests the alignment of knowledge from maintenance management, which make up the framework of Reliability Engineering, the knowledge of economic engineering in order to make tools and methods to make decisions in relation to physical assets companies. The objective of this study is to propose a model of asset replacement that considers variables Reliability and Sustainability, along with financial variables, using data envelopment analysis. The results present a conceptual model of asset replacement, with the inclusion of social and environmental variables and DEA application and also a case study with real data that assesses the replacement of equipment belonging to a producer of phosphoric acid.
12

Modelagem da disponibilidade de uma unidade geradora da UHE-Tucuruí

MOREIRA, Pedro Igor Carvalho 04 July 2013 (has links)
Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-11-12T16:11:38Z No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_ModelagemDisponibilidadeUnidade.pdf: 2938493 bytes, checksum: c9fb17fbdb7f0bba297ede0cc1d161b5 (MD5) / Approved for entry into archive by Ana Rosa Silva (arosa@ufpa.br) on 2014-11-13T11:48:58Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_ModelagemDisponibilidadeUnidade.pdf: 2938493 bytes, checksum: c9fb17fbdb7f0bba297ede0cc1d161b5 (MD5) / Made available in DSpace on 2014-11-13T11:48:58Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Dissertacao_ModelagemDisponibilidadeUnidade.pdf: 2938493 bytes, checksum: c9fb17fbdb7f0bba297ede0cc1d161b5 (MD5) Previous issue date: 2013 / Com o advindo do marco regulatório do Setor Elétrico Brasileiro, a partir de 2004, os agentes que atuam neste mercado têm experimentado um acirramento nas disputas por novos negócios, evidenciando um aumento de competitividade. A Disponibilidade dos Ativos Físicos e os Custos com Manutenção se apresentam como os pontos chave para a competitividade dos agentes. O presente trabalho tem por objetivo apresentar uma metodologia de Análise de Disponibilidade de Sistemas Reparáveis, durante as etapas de projeto ou de operação do sistema, contemplando a mensuração dos Custos com Manutenção versus o Desembolso com Aquisição para um nível esperado de desempenho. A metodologia para a Análise de Disponibilidade sugerida se utiliza da construção do Diagrama de Blocos do Sistema com respectivas descrições funcionais, exportação das informações para o formato de Árvore de Sucesso, composta de portas lógicas dos tipos "E" e "OU" as quais caracterizam um subsistema integrante do sistema principal. O analista pode reavaliar a topologia do sistema, agregando ou retirando redundâncias com a finalidade de ajustar o desempenho do projeto aos requisitos de Disponibilidade, Custo de Aquisição e Custos de Manutenção. Como resultados do trabalho foram identificadas lacunas normativas que definem a forma de controle do desempenho dos ativos, estabelecida uma sistemática de integração entre técnicas de modelagem de confiabilidade e disponibilidade, estabelecidos e incorporados indicadores de desempenho de Manutenção Programada em um agente do mercado, foram modelados e discutidos diferentes cenários para um Sistema de Circulação de Óleo de Mancal e foi aplicado o modelo a toda uma Unidade Geradora Hidráulica por meio da implementação computacional do modelo aos componentes críticos dos principais sistemas. / Since 2004, the regulatory rules in the Brazilian Electricity Sector has changed. The agents who act in this market have experienced a rise in new business disputes, showing an increase in competitiveness. The availability of physical assets and maintenance costs are presented as key points of these agents competitiveness. This work aims to present a methodology of Availability Analysis of Repairable Systems during the design or operational phases, covering the measurement of maintenance costs versus the acquisition costs to an expected performance level. The suggested methodology takes the System Block Diagram and exports to the Successful Tree Analysis format, composed by logic gates "AND" and "OR" where each represents a subsystem in the main system. The analyst may re-evaluate the system's topology, adding or removing redundancies in order to adjust the performance to the requirements of availability, acquisition and maintenance costs. As results of this work were identified gaps in the standards rules which defines how to control the assets performance, was established a systematic integration of modeling techniques for reliability and availability, performance indicators of Scheduled Maintenance were incorporated, different scenarios were modeled for an Oil Circulation System and was applied to an entire Hydraulic Generating Unit by modeling the critical components in the main systems.
13

Padrões baseados em metas: uma abordagem quantitativa aplicada à emissão de gases por veículos marítimos e automotivos. / Goal based standards: a quantitative approach applied to gases emissions of marine and automotive

Marcos Coitinho 09 February 2012 (has links)
Este trabalho propõe um método com base no planejamento estatístico de testes de confiabilidade para proporcionar um tratamento quantitativo aos dois primeiros níveis da abordagem de padrões baseados em metas (Goal-Based Standards). O uso do método é demonstrado em dois exemplos práticos, através da sua aplicação na meta de confiabilidade dos componentes do sistema de pós-tratamento de gases de exaustão, em motores a diesel de veículos automotivos e marítimos. Os fundamentos do trabalho incluem a teoria do planejamento estatístico de testes de confiabilidade, os princípios do GBS, tipos e características de metas de confiabilidade, a ferramenta de avaliação de segurança formal (FSA), e da análise do modo e efeito da falha (FMEA). A originalidade da contribuição do trabalho está na combinação das técnicas de planejamento de testes de confiabilidade com os princípios do GBS para quantificar o nível de atendimento das metas de confiabilidade. Dessa forma, é possível ajustar o programa de testes na verificação das metas de segurança, aumentando o conhecimento sobre o desempenho do sistema. O método é de simples aplicação permitindo a sua aplicação expedita e integrada aos processos de desenvolvimento de sistemas. / This research proposes a probabilistic method based on reliability test planning in order to provide a quantitative approach to the Tier I and II of the Goal-Based Standards (GBS). The use of the method is exhibited through its application in the reliability goal of the components of the exhaust gases post-treatment system in diesel engines for automotive and marine vehicles. The fundamentals of this work includes the theory of statistical design of reliability tests, the GBS principles, a brief description of the types and characteristics of reliability goals, the tool of Formal Safety Assessment (FSA) recommended for marítima projects, and the risk qualitative methodology based on Failure Mode Effect Analysis (FMEA). This theoretical framework was applied to two practical examples, one in the automotive industry and the other in the shipbuilding sector. The originality of this research lies in the combination of the reliability test planning techniques with the principles of GBS, in order to verify, from the whole project tests planning, the reliability goals of the basic components as a fundamental step in the assessment of system safety. The testing program can be adjusted to focus on verifying the safety goals, so that the level of knowledge about the product performance before it is delivered to the client. This work also offers the benefit of providing an easy method of system safety assessment, which allows a large number of companies to use it and to integrate it into their product development process.
14

Análise de substituição de ativos com base em variáveis de confiabilidade e sustentabilidade: uma aplicação DEA / Asset replacement analysis based on reliability and sustainability variables: an DEA application

Guilherme Augusto Roiz 14 March 2016 (has links)
As companhias estão inseridas em um contexto global de preocupação sustentável, onde questões ambientais e sociais acompanham as preocupações econômicas. Faz-se necessário englobar, de alguma forma, nas análises de viabilidade econômica ou ainda em modelagens de Vida Econômica e Reposição de Ativos, variáveis que possam representar aspectos sociais e ambientais. Nesse panorama entra a norma PAS-55 - Publicly Avaiable Specification - 55, publicada pela British Standards Institution, que visa aperfeiçoar o sistema de gestão de ativos físicos de maneira a permitir maiores resultados econômicos, sociais e ambientais, provenientes da utilização dos equipamentos, nas empresas. Os procedimentos previstos na norma PAS-55 sugerem o alinhamento de conhecimentos oriundos da gestão de manutenção, que compõem o arcabouço da Engenharia de Confiabilidade, a conhecimentos de Engenharia Econômica, de maneira a compor ferramentas e métodos para tomar decisões em relação aos ativos físicos de empresas. O objetivo do presente trabalho é propor um modelo de substituição de ativos que considere variáveis de Confiabilidade e Sustentabilidade, juntamente com variáveis financeiras, por meio da Análise Envoltória de Dados. Os resultados apresentam um modelo conceitual de substituição de ativos, com inclusão de variáveis socioambientais e aplicação DEA e, também, um estudo de caso com dados reais que avalia a substituição de um equipamento pertencente a uma empresa produtora de ácido fosfórico. / Companies are placed in a global context of sustainable concern where environmental and social issues accompanying economic concerns. It is necessary to include, in some way, the economic feasibility analysis or in modeling of Economic Life and Asset Replacement, variables that may pose social and environmental aspects. In this scenario enters the PAS-55 standard - Publicly Avaiable Specification - 55, published by the British Standards Institution, which aims to improve the management system of physical assets in order to allow greater economic results, social and environmental issues arising from the use of equipment, in companies. The procedures laid down in PAS-55 standard suggests the alignment of knowledge from maintenance management, which make up the framework of Reliability Engineering, the knowledge of economic engineering in order to make tools and methods to make decisions in relation to physical assets companies. The objective of this study is to propose a model of asset replacement that considers variables Reliability and Sustainability, along with financial variables, using data envelopment analysis. The results present a conceptual model of asset replacement, with the inclusion of social and environmental variables and DEA application and also a case study with real data that assesses the replacement of equipment belonging to a producer of phosphoric acid.
15

Le test unifié de cartes appliqué à la conception de systèmes fiables

Lubaszewski, Marcelo Soares January 1994 (has links)
Si on veut assurer de fawn efficace les tests de conception, de fabrication, de maintenance et le test accompli au cours de l'application pour les systemes electroniques, on est amend a integrer le test hors-ligne et le test en-ligne dans des circuits. Ensuite, pour que les systemes complexes tirent profit des deux types de tests, une telle unification doit etre &endue du niveau circuit aux niveaux carte et module. D'autre part, bien que rintegration des techniques de test hors-ligne et en-ligne fait qu'il est possible de concevoir des systemes pour toute application securitaire, le materiel ajoute pour assurer une haute siirete de fonctionnement fait que la fiabilite de ces systemes est reduite, car la probabilite d'occurrence de fautes augmente. Confront& a ces deux aspects antagoniques, cette these se fixe l'objectif de trouver un compromis entre la securite et la fiabilite de systemes electroniques complexes. Ainsi, dans un premier temps, on propose une solution aux problemes de test hors-ligne et de diagnostic qui se posent dans les &apes intermediaires de revolution vers les cartes 100% compatibles avec le standard IEEE 1149.1 pour le test "boundary scan". Une approche pour le BIST ("Built-In Self-Test") des circuits et connexions "boundary scan" illustre ensuite retape ultime du test hors-ligne de cartes. Puis, le schema UBIST ("Unified BIST") - integrant les techniques BIST et "self-checking" pour le test en-ligne de circuits, est combine au standard IEEE 1149.1, afin d'obtenir une strategie de conception en vue du test unifie de connexions et circuits montes sur des cartes et modules. Enfin, on propose un schema tolerant les fautes et base sur la duplication de ces modules securitaires qui assure la competitivite du systeme resultant du point de vue de la fiabilite, tout en gardant sa silrete inherente. / On one hand, if the goal is to ensure that the design validation, the manufacturing and the maintenance testing, along with the concurrent error detection are efficiently performed in electronic systems, one is led to integrate the off-line and the on-line testing into circuits. Then, for complex systems to make profit of these two types of tests, such unification must be extended from the circuit to the board and module levels. On the other hand, although the unification of off-line and on-line testing techniques makes possible the design of systems suiting any safety application, the hardware added for increasing the application safety also decreases the system reliability, since the probability of occurrence of faults increases. Faced to these two antagonist aspects, this thesis aims at finding a compromise between the safety and the reliability of complex electronic systems. Thus, firstly we propose a solution to the off-line test and diagnosis problems found in the intermediate steps in the evolution towards boards which are 100% compliant with the IEEE standard 1149.1 for boundary scan testing. An approach for the BIST (Built-In Self-Test) of boundary scan circuits and interconnects then illustrates the ultimate step in the board off-line testing. Next, the UBIST (Unified BIST) scheme - merging BIST and self-checking capabilities for circuit on-line testing, is combined with the IEEE standard 1149.1, in order to obtain a design strategy for unifying the tests of interconnects and circuits populating boards and modules. Finally, we propose a fault-tolerant scheme based on the duplication of these kind of modules which ensures the competitivity of the resulting system in terms of reliability at the same time as preserving the inherent module safety.
16

Le test unifié de cartes appliqué à la conception de systèmes fiables

Lubaszewski, Marcelo Soares January 1994 (has links)
Si on veut assurer de fawn efficace les tests de conception, de fabrication, de maintenance et le test accompli au cours de l'application pour les systemes electroniques, on est amend a integrer le test hors-ligne et le test en-ligne dans des circuits. Ensuite, pour que les systemes complexes tirent profit des deux types de tests, une telle unification doit etre &endue du niveau circuit aux niveaux carte et module. D'autre part, bien que rintegration des techniques de test hors-ligne et en-ligne fait qu'il est possible de concevoir des systemes pour toute application securitaire, le materiel ajoute pour assurer une haute siirete de fonctionnement fait que la fiabilite de ces systemes est reduite, car la probabilite d'occurrence de fautes augmente. Confront& a ces deux aspects antagoniques, cette these se fixe l'objectif de trouver un compromis entre la securite et la fiabilite de systemes electroniques complexes. Ainsi, dans un premier temps, on propose une solution aux problemes de test hors-ligne et de diagnostic qui se posent dans les &apes intermediaires de revolution vers les cartes 100% compatibles avec le standard IEEE 1149.1 pour le test "boundary scan". Une approche pour le BIST ("Built-In Self-Test") des circuits et connexions "boundary scan" illustre ensuite retape ultime du test hors-ligne de cartes. Puis, le schema UBIST ("Unified BIST") - integrant les techniques BIST et "self-checking" pour le test en-ligne de circuits, est combine au standard IEEE 1149.1, afin d'obtenir une strategie de conception en vue du test unifie de connexions et circuits montes sur des cartes et modules. Enfin, on propose un schema tolerant les fautes et base sur la duplication de ces modules securitaires qui assure la competitivite du systeme resultant du point de vue de la fiabilite, tout en gardant sa silrete inherente. / On one hand, if the goal is to ensure that the design validation, the manufacturing and the maintenance testing, along with the concurrent error detection are efficiently performed in electronic systems, one is led to integrate the off-line and the on-line testing into circuits. Then, for complex systems to make profit of these two types of tests, such unification must be extended from the circuit to the board and module levels. On the other hand, although the unification of off-line and on-line testing techniques makes possible the design of systems suiting any safety application, the hardware added for increasing the application safety also decreases the system reliability, since the probability of occurrence of faults increases. Faced to these two antagonist aspects, this thesis aims at finding a compromise between the safety and the reliability of complex electronic systems. Thus, firstly we propose a solution to the off-line test and diagnosis problems found in the intermediate steps in the evolution towards boards which are 100% compliant with the IEEE standard 1149.1 for boundary scan testing. An approach for the BIST (Built-In Self-Test) of boundary scan circuits and interconnects then illustrates the ultimate step in the board off-line testing. Next, the UBIST (Unified BIST) scheme - merging BIST and self-checking capabilities for circuit on-line testing, is combined with the IEEE standard 1149.1, in order to obtain a design strategy for unifying the tests of interconnects and circuits populating boards and modules. Finally, we propose a fault-tolerant scheme based on the duplication of these kind of modules which ensures the competitivity of the resulting system in terms of reliability at the same time as preserving the inherent module safety.
17

Le test unifié de cartes appliqué à la conception de systèmes fiables

Lubaszewski, Marcelo Soares January 1994 (has links)
Si on veut assurer de fawn efficace les tests de conception, de fabrication, de maintenance et le test accompli au cours de l'application pour les systemes electroniques, on est amend a integrer le test hors-ligne et le test en-ligne dans des circuits. Ensuite, pour que les systemes complexes tirent profit des deux types de tests, une telle unification doit etre &endue du niveau circuit aux niveaux carte et module. D'autre part, bien que rintegration des techniques de test hors-ligne et en-ligne fait qu'il est possible de concevoir des systemes pour toute application securitaire, le materiel ajoute pour assurer une haute siirete de fonctionnement fait que la fiabilite de ces systemes est reduite, car la probabilite d'occurrence de fautes augmente. Confront& a ces deux aspects antagoniques, cette these se fixe l'objectif de trouver un compromis entre la securite et la fiabilite de systemes electroniques complexes. Ainsi, dans un premier temps, on propose une solution aux problemes de test hors-ligne et de diagnostic qui se posent dans les &apes intermediaires de revolution vers les cartes 100% compatibles avec le standard IEEE 1149.1 pour le test "boundary scan". Une approche pour le BIST ("Built-In Self-Test") des circuits et connexions "boundary scan" illustre ensuite retape ultime du test hors-ligne de cartes. Puis, le schema UBIST ("Unified BIST") - integrant les techniques BIST et "self-checking" pour le test en-ligne de circuits, est combine au standard IEEE 1149.1, afin d'obtenir une strategie de conception en vue du test unifie de connexions et circuits montes sur des cartes et modules. Enfin, on propose un schema tolerant les fautes et base sur la duplication de ces modules securitaires qui assure la competitivite du systeme resultant du point de vue de la fiabilite, tout en gardant sa silrete inherente. / On one hand, if the goal is to ensure that the design validation, the manufacturing and the maintenance testing, along with the concurrent error detection are efficiently performed in electronic systems, one is led to integrate the off-line and the on-line testing into circuits. Then, for complex systems to make profit of these two types of tests, such unification must be extended from the circuit to the board and module levels. On the other hand, although the unification of off-line and on-line testing techniques makes possible the design of systems suiting any safety application, the hardware added for increasing the application safety also decreases the system reliability, since the probability of occurrence of faults increases. Faced to these two antagonist aspects, this thesis aims at finding a compromise between the safety and the reliability of complex electronic systems. Thus, firstly we propose a solution to the off-line test and diagnosis problems found in the intermediate steps in the evolution towards boards which are 100% compliant with the IEEE standard 1149.1 for boundary scan testing. An approach for the BIST (Built-In Self-Test) of boundary scan circuits and interconnects then illustrates the ultimate step in the board off-line testing. Next, the UBIST (Unified BIST) scheme - merging BIST and self-checking capabilities for circuit on-line testing, is combined with the IEEE standard 1149.1, in order to obtain a design strategy for unifying the tests of interconnects and circuits populating boards and modules. Finally, we propose a fault-tolerant scheme based on the duplication of these kind of modules which ensures the competitivity of the resulting system in terms of reliability at the same time as preserving the inherent module safety.

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