344 resultados para grounding
Resumo:
A procedure is proposed to accurately model thin wires in lossy media by finite element analysis. It is based on the determination of a suitable element width in the vicinity of the wire, which strongly depends on the wire radius to yield accurate results. The approach is well adapted to the analysis of grounding systems. The numerical results of the application of finite element analysis with the suitably chosen element width are compared with both analytical results and those computed by a commercial package for the analysis of grounding systems, showing very good agreement.
Resumo:
The purpose of this article is to present a quantitative analysis of the human failure contribution in the collision and/or grounding of oil tankers, considering the recommendation of the ""Guidelines for Formal Safety Assessment"" of the International Maritime Organization. Initially, the employed methodology is presented, emphasizing the use of the technique for human error prediction to reach the desired objective. Later, this methodology is applied to a ship operating on the Brazilian coast and, thereafter, the procedure to isolate the human actions with the greatest potential to reduce the risk of an accident is described. Finally, the management and organizational factors presented in the ""International Safety Management Code"" are associated with these selected actions. Therefore, an operator will be able to decide where to work in order to obtain an effective reduction in the probability of accidents. Even though this study does not present a new methodology, it can be considered as a reference in the human reliability analysis for the maritime industry, which, in spite of having some guides for risk analysis, has few studies related to human reliability effectively applied to the sector.
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We present a two-level model of concurrent communicating systems (CCS) to serve as a basis formachine consciousness. A language implementing threads within logic programming is ¯rstintroduced. This high-level framework allows for the de¯nition of abstract processes that can beexecuted on a virtual machine. We then look for a possible grounding of these processes into thebrain. Towards this end, we map abstract de¯nitions (including logical expressions representingcompiled knowledge) into a variant of the pi-calculus. We illustrate this approach through aseries of examples extending from a purely reactive behavior to patterns of consciousness.
Resumo:
The subject of this master’s thesis is to research grounding in a particular wind power application. The aim is to define how the grounding from different points effects to the function of the whole system. The investigated subjects are generator voltage spikes, ground currents and system fault situations. The first part of this thesis represents power electronics, which is commonly used in wind power systems. The second part concentrates more to the grounding, electrical safety demands and potential fault situations. The object of the simulations is to investigate voltage spikes and fault situations. Measurements will be made with small-scale setup and in the last part simulation and measurement results are compared to each other and to a full-scale system.
Resumo:
¿Qué significa exactamente el concepto anglosajón de Grounding? ¿Qué técnicas podemos utilizar para ayudar a las personas a estar más conectadas con su cuerpo y enraizadas en su realidad? Esta tesina analiza este concepto clave en Danza Movimiento Terapia (DMT) basado en la psicoterapia corporal de la bioenergética, fundada por Alexander Lowen, en Estados Unidos, en 1954. Revisaremos el concepto según Lowen y la bioenergética actual y lo analizaremos bajo la perspectiva de la DMT. En la segunda parte, se abordan los usos y aplicaciones del concepto con diversos ejercicios corporales de grounding o enraizamiento de tipo físico, sensorial, emocional y relacional, realizados en sesiones de DMT (años 2010-12), con dos poblaciones específicas (gente mayor con demencia y adultos con discapacidad psíquica). Las aplicaciones y usos del concepto de grounding son muy diversos y pueden beneficiar a todo tipo de personas, en el ámbito personal y/o laboral y no sólo a las personas consideradas “enfermas”.
Resumo:
Sediments recovered from seven Last Glacial Maximum grounding lines sites, around the Antarctic Peninsula, were analyzed using micromorphology. This is the first evidence that grounding line sediments from around the Antarctic Peninsula have complex deformational histories and subglacial origins. It was determined that grounding zone wedge contain multiple units, or diamicton layers, with homogenized boundaries. The multiple diamicton units / layers are due to the accretionary formation of a grounding line wedge. All the sediments were deposited via deformation, and continual reincorporation, homogenization of lower diamicton layers by upper diamicton layers produced what macroscopically appeared to be a single massive diamicton unit. The morainal ridge that was sampled, alternatively, is composed of a single unit, or diamicton layer, that was subglacial in origin and believed to have been pushed out to form a ridge that was subsequently deformed via glacial push.
Resumo:
In this paper, I seek to undermine G.A. Cohen’s polemical use of a metaethical claim he makes in his article, ‘Facts and Principles’, by arguing that that use requires an unsustainable equivocation between epistemic and logical grounding. I begin by distinguishing three theses that Cohen has offered during the course of his critique of Rawls and contractualism more generally, the foundationalism about grounding thesis, the justice as non-regulative thesis, and the justice as all-encompassing thesis, and briefly argue that they are analytically independent of each other. I then offer an outline of the foundationalism about grounding thesis, characterising it, as Cohen does, as a demand of logic. That thesis claims that whenever a normative principle is dependent on a fact, it is so dependent in virtue of some other principle. I then argue that although this is true as a matter of logic, it, as Cohen admits, cannot be true of actual justifications, since logic cannot tell us anything about the truth as opposed to the validity of arguments. Facts about a justification cannot then be decisive for whether or not a given argument violates the foundationalism about grounding thesis. As long as, independently of actual justifications, theorists can point to plausible logically grounding principles, as I argue contractualists can, Cohen’s thesis lacks critical bite.
Resumo:
The accurate identification of features of dynamical grounding systems are extremely important to define the operational safety and proper functioning of electric power systems. Several experimental tests and theoretical investigations have been carried out to obtain characteristics and parameters associated with the technique of grounding. The grounding system involves a lot of non-linear parameters. This paper describes a novel approach for mapping characteristics of dynamical grounding systems using artificial neural networks. The network acts as identifier of structural features of the grounding processes. So that output parameters can be estimated and generalized from an input parameter set. The results obtained by the network are compared with other approaches also used to model grounding systems.
Resumo:
In some applications like fault analysis, fault location, power quality studies, safety analysis, loss analysis, etc., knowing the neutral wire and ground currents and voltages could be of particular interest. In order to investigate effects of neutrals and system grounding on the operation of the distribution feeders with faults, in this research a hybrid short circuit algorithm is generalized. In this novel use of the technique, the neutral wire and assumed ground conductor are explicitly represented. Results obtained from several case studies using IEEE 34-node test network are presented and discussed.
Resumo:
The aim of this article is to analyse the meaning of Mercosur for Brazilian foreign policy. To this end, we discuss the perceptions of the Brazilian elites concerning the regional integration process. The defence of the principle of inter-governmentalism is related to the conception of Mercosur's place within Brazil's international relations. The fact that principles such as universalism and sovereignty are very highly valued ends up affecting the deepening of the integration. The hypothesis of this article is that the Mercosur structure is in line with the perceptions of part of the Brazilian elites, which has put less emphasis on integration since the late 1990s. Our argument is that the current structure is insufficient to guarantee the dynamics of integration.
Resumo:
Iceberg calving has been assumed to be the dominant cause of mass loss for the Antarctic ice sheet, with previous estimates of the calving flux exceeding 2,000 gigatonnes per year. More recently, the importance of melting by the ocean has been demonstrated close to the grounding line and near the calving front. So far, however, no study has reliably quantified the calving flux and the basal mass balance (the balance between accretion and ablation at the ice-sheet base) for the whole of Antarctica. The distribution of fresh water in the Southern Ocean and its partitioning between the liquid and solid phases is therefore poorly constrained. Here we estimate the mass balance components for all ice shelves in Antarctica, using satellite measurements of calving flux and grounding-line flux, modelled ice-shelf snow accumulation rates and a regional scaling that accounts for unsurveyed areas. We obtain a total calving flux of 1,321 ± 144 gigatonnes per year and a total basal mass balance of -1,454 ± 174 gigatonnes per year. This means that about half of the ice-sheet surface mass gain is lost through oceanic erosion before reaching the ice front, and the calving flux is about 34 per cent less than previous estimates derived from iceberg tracking. In addition, the fraction of mass loss due to basal processes varies from about 10 to 90 per cent between ice shelves. We find a significant positive correlation between basal mass loss and surface elevation change for ice shelves experiencing surface lowering and enhanced discharge. We suggest that basal mass loss is a valuable metric for predicting future ice-shelf vulnerability to oceanic forcing.