945 resultados para railway crossing


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Rolling Contact Fatigue (RCF) is one of the main issues that concern, at least initially, the head of the railway; progressively they can be of very high importance as they can propagate inside the material with the risk of damaging the railway. In this work, two different non-destructive techniques, infrared thermography (IRT) and fibre optics microscopy (FOM), were used in the inspection of railways for the tracing of defects and deterioration signs. In the first instance, two different approaches (dynamic and pulsed thermography) were used, whilst in the case of FOM, microscopic characterisation of the railway heads and classification of the deterioration -- damage on the railways according to the UIC (International Union of Railways) code, took place. Results from both techniques are presented and discussed.

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The Synapsing Variable Length Crossover (SVLC) algorithm provides a biologically inspired method for performing meaningful crossover between variable length genomes. In addition to providing a rationale for variable length crossover it also provides a genotypic similarity metric for variable length genomes enabling standard niche formation techniques to be used with variable length genomes. Unlike other variable length crossover techniques which consider genomes to be rigid inflexible arrays and where some or all of the crossover points are randomly selected, the SVLC algorithm considers genomes to be flexible and chooses non-random crossover points based on the common parental sequence similarity. The SVLC Algorithm recurrently "glues" or synapses homogenous genetic sub-sequences together. This is done in such a way that common parental sequences are automatically preserved in the offspring with only the genetic differences being exchanged or removed, independent of the length of such differences. In a variable length test problem the SVLC algorithm is shown to outperform current variable length crossover techniques. The SVLC algorithm is also shown to work in a more realistic robot neural network controller evolution application.

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Let $R_{t}=\sup_{0\leq s\leq t}X_{s}-X_{t}$ be a Levy process reflected in its maximum. We give necessary and sufficient conditions for finiteness of passage times above power law boundaries at infinity. Information as to when the expected passage time for $R_{t}$ is finite, is given. We also discuss the almost sure finiteness of $\limsup_{t\to 0}R_{t}/t^{\kappa}$, for each $\kappa\geq 0$.

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Results are presented of a study of a performance of various track-side railway noise barriers, determined by using a two- dimensional numerical boundary element model. The basic model uses monopole sources and has been adapted to allow the sources to exhibit dipole-type radiation characteristics. A comparison of boundary element predictions of the performance of simple barriers and vehicle shapes is made with results obtained by using the standard U.K. prediction method. The results obtained from the numerical model indicate that modifying the source to exhibit dipole characteristics becomes more significant as the height of the barrier increases, and suggest that for any particular shape, absorbent barriers provide much better screening efficiency than the rigid equivalent. The cross-section of the rolling stock significantly affects the performance of rigid barriers. If the position of the upper edge is fixed, the results suggest that simple absorptive barriers provide more effective screening than tilted barriers. The addition of multiple edges to a barrier provides additional insertion loss without any increase in barrier height.

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This paper examines attitudes towards Radio Frequency Identification (RFID) technology and explores the wider concerns of the ever increasing prospect of social tagging. Capturing vignettes and narratives from a sample of study participants, the paper highlights concerns about adopting RFID implements now and in the future. The views captured through qualitative methodology act as the platform for a wider argument concerning the human rights and privacy intrusion concerns over IT applications. Intended as an insight into the reality of technology impact, this paper lists a series of questions for leaders to consider over matters of human rights specifically concerning RFID adoption. The authors conclude that caution, naivety and fear are the underlying reasons for society accepting RFIDs without question and that RFIDs will be a part of everyday working and domestic life in the near future.

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This article examines a little known decision of the Judicial Committee of the Privy Council: Grand Trunk Railway Company of Canada v Robinson (1915). The examination is historical and it provides a different insight into the understanding of privity of contract, a doctrine central to contract law. The examination reveals a process of trans-Atlantic legal migration in which English law was applied to resolve an Ontario case. The nature of the resolution is surprising because it appears to conflict with the better known decision of the House of Lords, Dunlop Pneumatic Tyre Company, Limited v Selfridge and Company, Limited, which a similarly constituted panel delivered in the same week. This article argues that there was a greater malleability in the resolution of cases concerned with privity than was thought to have existed. It is also argued that the power of Canadian railway capitalism is a significant factor in understanding the legal resolution of the case. Finally, it the article considers the use of English and American precedents relevant to the case. The application of English precedents to the case led to a resolution not entirely befitting Canadian conditions.

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Families at the bottom end of the Edwardian white-collar income spectrum demonstrated middle-class status through observable consumption, at the cost of squeezing other expenditures, including ‘necessities’. This had negative economic impacts, lowering living standards due to inefficiently high budget shares for positional goods. Drawing on the work of Pierre Bourdieu, we examine how railway clerks sought to demonstrate ‘distinction’ from manual workers through certain conspicuous expenditures and how this strategy was progressively undermined by falling real incomes over the Edwardian period.

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A key issue in UK railway history is whether the railway system was an efficient response to the traffic requirements of the economy. The UK railway system was constructed entirely by private enterprise with minimal state subsidies. This chapter considers whether the railway system was 'over-built' because the government ignored the advice of the Railway Committee of the Board of Trade. The chapter suggests that the system was over-built by about 35 per cent. The causes of this over-building are investigated and are found to be mainly social and political failures arising from distrust between MPs and civil servants and public pressure on local MPs to ensure that their constituencies were well served by railways.