Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-07T12:50:45Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) vcos_dissertacao_biblio.pdf: 1665179 bytes, checksum: 372d9b7e2643e2c4572b6b7e5b90dfdd (MD5) / Made available in DSpace on 2016-04-07T12:50:45Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) vcos_dissertacao_biblio.pdf: 1665179 bytes, checksum: 372d9b7e2643e2c4572b6b7e5b90dfdd (MD5) Previous issue date: 2015-08-07 / A popularização dos dispositivos móveis e o intenso crescimento das aplicações destinadas a estes dispositivos favorece tais elementos como ferramentas de trabalho para inúmeras áreas, incluindo atenção saúde, uma área em constante evolução. A tecnologia móvel auxilia a área médica oferecendo facilidades e novos recursos às equipes médicas e pacientes, devido a isto, os dispositivos móveis e suas aplicações dedicadas contribuem como uma ferramenta de apoio no contexto de atenção à saúde. As aplicações de mensagens instantâneas facilitam a comunicação, de forma que as equipes médicas possam ter acesso constante aos dados de monitoramento de seus pacientes através do uso de seus dispositivos móveis. O dispositivo móvel é um elemento integrante do ambiente de computação móvel em nuvem e conhecer o tempo médio em que este dispositivo irá funcionar sem que apresente falhas é o ponto de partida para avaliar o desempenho desta ferramenta utilizada pelas equipes de atenção à saúde. O dispositivo móvel é composto por diversos elementos incluindo bateria e as interfaces de rede que são identificadas como componentes relevantes na disponibilidade para utilização constante das aplicações nestes dispositivos. A utilização de modelos de avaliação de desempenho auxilia na previsibilidade do comportamento do dispositivo móvel no ambiente, desta forma é adotado modelos de diagramas de blocos para avaliar a confiabilidade e disponibilidade do dispositivo, juntamente com outros modelos a fim de avaliar o desempenho de elementos específicos do dispositivo móvel, tais como, a conectividade das interfaces de rede através do uso de redes de Petri e o consumo de energia através de cadeias de Markov; com base nos modelos elaborados distintos cenários são avaliados para comparar o desempenho do consumo de energia das quatro estratégias de sincronismo mais usuais de aplicações de comunicação instantânea e desta forma compreender o impacto de adoção destas no desenvolvimento das aplicações voltada à atenção à saúde. Os modelos elaborados permitem avaliar o desempenho dos protocolos de aplicação e o impacto das interfaces de rede do dispositivo para preservar o recurso de energia do dispositivo. / More and more mobile devices and the sharp increase in applications for these devices favors such elements as work tools for many areas, including health care, an area in constant evolution. Mobile technology helps medical facilities and providing new resources to medical staff and patients, due to this, mobile devices and their dedicated applications contribute as a support tool in the context health care. The instant messaging applications facilitate communication so that medical staff can have constant access to their patient’s monitoring data through their mobile devices use. The mobile device is a Mobile Cloud Computing component element. To know the average time this device will function without presenting faults is the starting point for assessing this tool’s performance used by health care teams. The mobile consists of various elements including battery and network interfaces, and these identified as relevant components in readiness for constant use of applications on these devices. The evaluation models help predictability mobile device behavior in the environment. The block diagrams model was adopted to assess the device’s reliability and availability. Like other models to evaluate the specific elements performance of the mobile device. The network interfaces connectivity through the Petri networks use, and energy consumption using Markov chains. With these models, different scenarios are evaluated to compare the energy consumption performance of the four most common timing strategies of instant messaging applications. Thus understand the impact of adopting these in the development of applications dedicated to health care. Elaborate models for evaluating the performance of application protocols and the effects of the device’s network interfaces to preserve the device’s energy resource.

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Within maintenance activities and industrial operations, human is subjected to different kind of stresses and situation that could result in mistakes and accidents. The human errors in maintenance and manufacturing are an unexplored latter such that a little focusis invested in this area. The report aims to widen up the understanding of the human error in maintenance and manufacturing area. Aviation and marine operations are the most sectors that are subjected to human errors according tothe literature. There aredifferent types of human error that have effect on quality and overall effectivity. Human reliability models are one method to quantify human errors and usually used for the identification of human errors and HEP calculation. The most common reliability measurement methods are HEART, THERP and SLIM which are used depending on application and industry. As a part of efforts to define differences between those reliability models, literature including different industries is used and itis found that expert judgement influences the success and accuracy of such methods. There are many causes for human errors depending on the application but, communication and procedures followed are the most contributing factors. There is always a probability of existence of human errors as the mistake done by workers are inevitable. Industry 4.0 can help in decreasing human errors through the introduction of operator 4.0 as well as other approaches like training and upgrading organizational standards.

This thesis deals with the systems reliability. At First, there is discussed the concept of reliability itself and its indicators, which can specifically express reliability. The second chapter describes the different kinds of reliability models for simple and complex systems. It further describes the basic methods for construction of reliability models. The fourth chapter is devoted to a very important Markov models. Markov models are very powerful and complex model for calculating the reliability of advanced systems. Their suitability is explained here for recovered systems, which may contain absorption states. The next chapter describes the standby redundancy. Discusses the advantages and disadvantages of static, dynamic and hybrid standby. There is described the influence of different load levels on the service life. The sixth chapter is devoted to the implementation, description of the application and description of the input file in XML format. There are discussed the results obtaining in experimental calculations.

The diploma thesis analyses the problem of the company efficiency and its evaluation. Theoretical basis was applied in the cooperative company, whose main activity is the custom-made furniture. The analysis of company efficiency was conducted on a base of a financial analysis. The concrete analysis includes: analysis of absolute indicators, differential indicators, ratio indicators, Du Pont analysis, bankruptcy and value indicators, economic value added, Spider analysis. The conclusion contains suggestions for improving the current company situation.

[ES] La seguridad ha sido, es y seguirá siendo una prioridad en la operación de las centrales nucleares para la producción de energía eléctrica. Uno de los grandes retos a los que se enfrenta la industria nuclear es el envejecimiento de las estructuras, sistemas y componentes (ESC) de seguridad. Actualmente, este hecho cobra especial relevancia porque un gran número de reactores está alcanzando el fin de su vida de diseño, debiendo afrontar próximamente una Revisión Periódica de Seguridad (RPS), que garantice el funcionamiento seguro de la central durante un periodo adicional denominado Opera-ción a Largo Plazo (OLP). El Análisis Probabilista de Seguridad (APS) es una herramienta fundamental para la gestión integral de la seguridad de una planta, tanto en el marco de la RPS como en la Toma de Decisiones Informada en el Riesgo (TDIR), siendo capaz de evaluar el incremento o disminución en el riesgo producido por un cambio determinado. Sin embargo, los modelos y datos actuales que lo integran no tienen en cuenta factores que influyen de forma determinante en el riesgo de una central. Por un lado, no tienen en cuenta el envejecimiento o la estrategia de pruebas y mantenimiento, en el caso del modelado de la fiabilidad e indisponibilidad de componentes. Por otro lado, no con-templan la imprecisión en el modelado de las acciones humanas, ni la inexactitud en la cuantificación de sus probabilidades de error. La presente tesis doctoral pretende actualizar y mejorar los modelos del APS, con vistas a su aplicación en el contexto de la RPS y de la TDIR. En este sentido, se establecen dos objetivos principales. En primer lugar, el desarrollo de un modelo RAM (fiabilidad, mantenibilidad y disponibilidad) dependiente del tiempo para componentes de seguridad, ajustado con datos reales de planta y con un nivel de detalle suficiente para recoger explícitamente en la edad del mismo, el efecto de las pruebas y el mantenimiento. En segundo lugar, mostrar las aplicaciones del APS para la TDIR. En primer término, se define un modelo de riesgo dependiente de la edad, a partir del mode-lo RAM previamente formulado, con el que seleccionar la mejor estrategia de pruebas y mantenimiento en un horizonte temporal dado. En segundo término, para mejorar el modelado del APS y la cuantificación de las probabilidades de error humano (PEH), se propone una metodología de evaluación de impacto en el riesgo para cambios en las acciones humanas y las Especificaciones Técnicas de Funcionamiento, que aprovecha los resultados del uso conjunto de los análisis de seguridad determinista y probabilista. Las aportaciones que conforman esta tesis doctoral se integran en la línea de investigación financiada por el Ministerio de Economía y Empresa en el proyecto ENE2016-80401-R, "Armonización de requisitos de vigilancia y mantenimiento en centrales nucleares con información en el riesgo" y la ayuda para contratos predoctorales para la formación de doctores BES-2014-067602. / [CA] La seguretat ha sigut, és i continuarà sent una prioritat en l'operació de les centrals nuclears par a la producció d'energia elèctrica. Un del grans reptes als que s'enfronta la industria nuclear es l'envelliment de les estructures, sistemes i components de seguretat. Actualment, aquest fet té especial rellevància perquè un gran nombre de reactors està arribant a la fi de la seua vida de disseny, havent d'afrontar pròximament una Revisió Periòdica de Seguretat (RPS), que garantirà el funcionament segur de la central durant un període addicional conegut com Operació a Llarg Termini (OLP). L'Anàlisi Probabilista de Seguretat es una ferramenta fonamental per a la gestió integral de la seguretat d'una planta, tant en el marc de la RPS com en la presa de decisions informades en el risc (TDIR), sent capaç d'avaluar l'increment o disminució en el risc produït per un canvi determinat. No obstant això, els models i dades actuals que ho integren no tenen en compte factors que influeixen de forma determinant en el risc d'una central. Per una banda, no consideren l'envelliment o l'estratègia de proves i manteniment, en el cas del modelat de la fiabilitat i indisponiblitat de components. Per altra banda, no contemplen la imprecisió en el modelat de les acciones humanes, ni la inexactitud en la quantificació de la probabilitat d'error de les mateixes. La present tesi doctoral pretén actualitzar i millorar els models APS, amb la intenció d'aplicar-los en el context de la RPS y la TDIR. En aquest sentit, s'estableixen dos objectius principals. En primer lloc, el desenvolupament d'un model RAM (fiabilitat, mantenibilitat i disponibilitat) dependent del temps per a components de seguretat, ajustat amb dades reals de planta i amb un nivell de detall suficient per a recollir explícitament en l'edat del mateix, la política de proves i manteniment a la que es sotmès. En segon lloc, mostrar les aplicacions de l'APS per a la TDIR. En primer terme, es defineix un model de risc dependent de l'edat, a partir del model RAM prèviament formulat, amb el qual seleccionar la millor estratègia de proves i manteniment en un horitzó temporal determinat. En segon terme, per a millorar el modelat de l'APS i la quantificació de les probabilitats d'error humà (PEH), es proposa una metodologia d'avaluació d'impacte en el risc per a canvis en les accions humanes i en les Especificacions Tècniques de Funcionament, que aprofita els resultats de l'ús conjunt dels anàlisis determinista i probabilista. Les aportacions que formen part d'aquesta tesi doctoral s'integren en la línia d'investigació finançada pel Ministeri d'Economia i Empresa en el projecte ENE2016-80401-R, "Armonización de requisitos de vigilancia y mantenimiento en centrales nucleares con información en el riesgo" i l'ajuda per a contractes predoctorals per a la formació de doctors BES-2014-067602. / [EN] Safety always has been and always will be a priority in nuclear power plant operation to generate electricity. One of the major challenges of nuclear industry is the ageing of safety-related structures, systems and components (SSC). Presently, this fact gains relevance due to several reactors are reaching their design life, having to conduct a Periodic Safety Review (PSR) that assures safety operation for an additional period better-known as Long Term Operation (LTO) Probabilistic Safety Assessment (PSA) is an essential tool in an integral NPP safety management, both PSR framework and Risk Informed Decision Making (RIDM), being able to evaluate a risk increase or decrease for any specific change on the plant. However, current PSA models and data do not consider factors, which have an impact in the overall risk of the plant. On the one hand, they do not take into account the effect of ageing nor maintenance and testing program, in the case of reliability and unavailability modelling. On the other hand, human actions modelling and their associated error probabilities are characterized by its inaccuracy and uncertainty. This Ph. Dissertation aims to update and improve PSA models, in order to apply with-in the framework of PSR and RIDM. In this sense, two main objectives are established. Firstly, the development of a time dependent RAM (reliability, availability and maintainability) for safety-related components, fitted with a historical plant data and with enough level of detail to include the effects of testing and maintenance activities in the age of the component. Secondly, it shows PSA applications of new models in RIDM. In the first place, it defines an age-dependent risk model based on the RAM model previously formulated, which helps to select the best approach of maintenance and testing activities for a specific timeline. In the second place, to improve PSA modelling and human error probabilities (HEP) quantification, a methodology is pro-posed to evaluate the risk impact of human actions and TS changes, taking advantage of combining DSA and PSA insights. The work of this thesis is part of the research supported by the Ministry of Economy and Business in the project ENE2016-80401-R, "Risk Informed Harmonization of Surveillance Requirements and Maintenance in Nuclear Power Plants", and in the Doctoral Fellowship BES-2014-067602. / Las aportaciones que conforman esta tesis doctoral se integran en la línea de investigación financiada por el Ministerio de Economía y Empresa en el proyecto ENE2016- 80401-R, “Armonización de requisitos de vigilancia y mantenimiento en centrales nucleares con información en el riesgo” y la ayuda para contratos predoctorales para la formación de doctores BES-2014-067602. / Martorell Aigües, P. (2019). Aportaciones al modelado de la indisponibilidad de componentes y la fiabilidad humana para la mejora de la seguridad de las centrales nucleares informada en el riesgo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/118794

Monte Carlo simulation techniques have emerged as widely accepted computing tools in tackling many problems in modern structural mechanics. Apart from developments in computational hardware, which have undoubtedly made simulation strategies practically feasible, the success of Monte Carlo simulations has also resulted equally significantly from the methodological developments aimed at controlling sampling variance of the Monte Carlo estimates. The study reported in the present thesis is aimed at developing and validating Monte Carlo simulation based approaches with inbuilt variance reduction capabilities to deal with problems of time variant reliability modeling, random vibration testing, and updating reliability models for statically/dynamically loaded instrumented structures. The relevant literature has been reviewed in Chapter 1. Time variant reliability analysis of randomly parametered and randomly driven non-linear vibrating systems has been tackled by combining two Monte Carlo variance reduction strategies into a single framework (Chapter 2). The first of these strategies is based on the application of the Girsanov transformation to account for the randomness in dynamic excitations and, the second approach is fashioned after the subset simulation method to deal with randomness in system parameters. A novel experimental test procedure to estimate the reliability of structural dynamical systems under excitations specified via random process models has been proposed (Chapter 3). The samples of random excitations to be used in the test are modified by the addition of an artificial control force. An unbiased estimator for the reliability is derived based on measured ensemble of responses under these modified inputs based on the tenets of Girsanov’s transformation. The study observes that an acceptable choice for the control force (that can reduce the sampling variance of the estimator) can be made solely based on experimental techniques. This permits the proposed procedure to be applied in the experimental study of time variant reliability of complex structural systems which are difficult to model mathematically. Illustrative example consists of a multi-axes shake table study on bending-torsion coupled, geometrically non-linear, five-storey frame under uni/bi-axial, non-stationary, random base excitation. The first order reliability method (FORM) and inverse FORM have been extended to handle the problem of updating reliability models for existing, statically loaded structures based on measured responses (Chapter 4). The proposed procedures are implemented by combining Matlab based reliability modules with finite element models residing on the Abaqus software. Numerical illustrations on linear and non-linear frames are presented. A solution strategy within the framework of Monte Carlo simulation based dynamic state estimation method and Girsanov’s transformation for variance reduction has been developed to tackle the problem of updating the reliability of instrumented structures based on measured response under random dynamic loading (Chapter 5). For linear Gaussian state space models, the solution is developed based on continuous version of the Kalman filter, while, for non-linear and (or) non-Gaussian state space models, bootstrap particle filters are adopted. Results from laboratory testing of an archetypal five storey bending-torsion coupled frame under seismic base motions form the basis of one of the illustrative examples. A set of three annexures contain details of numerical methods for discretizing Ito’s differential equations (Annexure 1), working of the Girsanov transformation through Kolmogorov’s equations (Annexure 2) and tools for interfacing Matlab and Abaqus codes (Annexure 3).