10 resultados para SYSTEM FAILURE ANALYSIS
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Some of the properties sought in seismic design of buildings are also considered fundamental to guarantee structural robustness. Moreover, some key concepts are common to both seismic and robustness design. In fact, both analyses consider events with a very small probability of occurrence, and consequently, a significant level of damage is admissible. As very rare events,in both cases, the actions are extremely hard to quantify. The acceptance of limited damage requires a system based analysis of structures, rather than an element by element methodology, as employed for other load cases. As for robustness analysis, in seismic design the main objective is to guarantee that the structure survives an earthquake, without extensive damage. In the case of seismic design, this is achieved by guaranteeing the dissipation of energy through plastic hinges distributed in the structure. For this to be possible, some key properties must be assured, in particular ductility and redundancy. The same properties could be fundamental in robustness design, as a structure can only sustain significant damage if capable of distributing stresses to parts of the structure unaffected by the triggering event. Timber is often used for primary load‐bearing elements in single storey long‐span structures for public buildings and arenas, where severe consequences can be expected if one or more of the primary load bearing elements fail. The structural system used for these structures consists of main frames, secondary elements and bracing elements. The main frame, composed by columns and beams, can be seen as key elements in the system and should be designed with high safety against failure and under strict quality control. The main frames may sometimes be designed with moment resisting joints between columns and beams. Scenarios, where one or more of these key elements, fail should be considered at least for high consequence buildings. Two alternative strategies may be applied: isolation of collapsing sections and, provision of alternate load paths [1]. The first one is relatively straightforward to provide by deliberately designing the secondary structural system less strong and stiff. Alternatively, the secondary structural system and the bracing system can be design so that loss of capacity in the main frame does not lead to the collapse. A case study has been selected aiming to assess the consequences of these two different strategies, in particular, under seismic loads.
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RESUMO - A segurança do doente é um tema que tem sido amplamente estudado por todo o mundo. Com o desenvolvimento do conhecimento, das técnicas e o advento das learning organizations é possível detectar as áreas onde existe potencial risco, conhecer o número de incidentes de forma sistemática, promover a evolução das técnicas nas áreas mais urgentes, determinar o impacto de todos os incidentes e eventos adversos, aprender com eles e promover modificações nas organizações. A neonatologia não foi excepção, pelo que se pretende a criação e validação de um sistema de notificação de eventos adversos e de incidentes, anónimo e não punitivo, adaptado a uma Unidade de Cuidados Intermédios Neonatal. O delineamento do estudo passou pela revisão bibliográfica para a construção de um sistema e posterior análise do mesmo por um painel de especialistas, para a selecção e consenso de itens que integraram o modelo. Por fim este sistema foi sujeito a um pré-teste. Com a aplicação da Técnica de Grupo Nominal constatou-se que a confidencialidade dos dados é um tema muito sensível aos profissionais. Na aplicação do pré-teste as categorias de incidentes notificados relacionam-se com medicação, ventilação e identificação. Assim sendo, este sistema detém validade interna, no entanto com a aplicação do pré-teste verificou-se que este perde validade externa, pelo que os resultados apresentados neste projecto de investigação não podem ser generalizados. A notificação é uma área para a qual os profissionais estão sensibilizados, no entanto, ainda encontra muitos entraves à sua implementação e consequentemente à colheita de dados.
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Thesis submitted to the Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia for the degree of Doctor of Philosophy in Environmental Engineering
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Assessing the safety of existing timber structures is of paramount importance for taking reliable decisions on repair actions and their extent. The results obtained through semi-probabilistic methods are unrealistic, as the partial safety factors present in codes are calibrated considering the uncertainty present in new structures. In order to overcome these limitations, and also to include the effects of decay in the safety analysis, probabilistic methods, based on Monte-Carlo simulation are applied here to assess the safety of existing timber structures. In particular, the impact of decay on structural safety is analyzed and discussed, using a simple structural model, similar to that used for current semi-probabilistic analysis.
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ABSTRACT - The Patient Protection and Affordable Care Act shook the foundations of the US health system, offering all Americans access to health care by changing the way the health insurance industry works. As President Obama signed the Act on 23 March 2010, he said that it stood for “the core principle that everybody should have some basic security when it comes to their health care”. Unlike the U.S., the Article 64 of the Portuguese Constitution provides, since 1976, the right to universal access to health care. However, facing a severe economic crisis, Portugal has, under the supervision of the Troika, a tight schedule to implement measures to improve the efficiency of the National Health Service. Both countries are therefore despite their different situation, in a conjuncture of reform and the use of new health management measures. The present work, using a qualitative research methodology examines the Affordable Care Act in order to describe its principles and enforcement mechanisms. In order to describe the reality in Portugal, the Portuguese health system and the measures imposed by Troika are also analyzed. The intention of this entire analysis is not only to disclose the innovative U.S. law, but to find some innovative measures that could serve health management in Portugal. Essentially we identified the Exchanges and Wellness Programs, described throughout this work, leaving also the idea of the possibility of using them in the Portuguese national health system.
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Dissertação para obtenção do Grau de Doutor em Ciências da Educação
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Based on the report for the unit “Project IV” of the PhD programme on Technology Assessment under the supervision of Dr.-Ing. Marcel Weil and Prof. Dr. António Brandão Moniz. The report was presented and discussed at the Doctorate Conference on Technologogy Assessment in July 2013 at the University Nova Lisboa, Caparica campus.
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Information systems are widespread and used by anyone with computing devices as well as corporations and governments. It is often the case that security leaks are introduced during the development of an application. Reasons for these security bugs are multiple but among them one can easily identify that it is very hard to define and enforce relevant security policies in modern software. This is because modern applications often rely on container sharing and multi-tenancy where, for instance, data can be stored in the same physical space but is logically mapped into different security compartments or data structures. In turn, these security compartments, to which data is classified into in security policies, can also be dynamic and depend on runtime data. In this thesis we introduce and develop the novel notion of dependent information flow types, and focus on the problem of ensuring data confidentiality in data-centric software. Dependent information flow types fit within the standard framework of dependent type theory, but, unlike usual dependent types, crucially allow the security level of a type, rather than just the structural data type itself, to depend on runtime values. Our dependent function and dependent sum information flow types provide a direct, natural and elegant way to express and enforce fine grained security policies on programs. Namely programs that manipulate structured data types in which the security level of a structure field may depend on values dynamically stored in other fields The main contribution of this work is an efficient analysis that allows programmers to verify, during the development phase, whether programs have information leaks, that is, it verifies whether programs protect the confidentiality of the information they manipulate. As such, we also implemented a prototype typechecker that can be found at http://ctp.di.fct.unl.pt/DIFTprototype/.