995 resultados para Railway permanent way


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This article presents a new and computationally efficient method of analysis of a railway track modelled as a continuous beam of 2N spans supported by elastic vertical springs. The main feature of this method is its important reduction in computational effort with respect to standard matrix methods of structural analysis. In this article, the whole structure is considered to be a repetition of a single one. The analysis presented is applied to a simple railway track model, i.e. to a repetitive beam supported on vertical springs (sleepers). The proposed method of analysis is based on the general theory of spatially periodic structures. The main feature of this theory is the possibility to apply Discrete Fourier Transform (DFT) in order to reduce a large system of q(2N + 1) linear stiffness equilibrium equations to a set of 2N + 1 uncoupled systems of q equations each. In this way, a dramatic reduction of the computational effort of solving the large system of equations is achieved. This fact is particularly important in the analysis of railway track structures, in which N is a very large number (around several thousands), and q = 2, the vertical displacement and rotation, is very small. The proposed method allows us to easily obtain the exact solution given by Samartín [1], i.e. the continuous beam railway track response. The comparison between the proposed method and other methods of analysis of railway tracks, such as Lorente de Nó and Zimmermann-Timoshenko, clearly shows the accuracy of the obtained results for the proposed method, even for low values of N. In addition, identical results between the proposed and the Lorente methods have been found, although the proposed method seems to be of simpler application and computationally more efficient than the Lorente one. Small but significative differences occur between these two methods and the one developed by Zimmermann-Timoshenko. This article also presents a detailed sensitivity analysis of the vertical displacement of the sleepers. Although standard matrix methods of structural analysis can handle this railway model, one of the objectives of this article is to show the efficiency of DFT method with respect to standard matrix structural analysis. A comparative analysis between standard matrix structural analysis and the proposed method (DFT), in terms of computational time, input, output and also software programming, will be carried out. Finally, a URL link to a MatLab computer program list, based on the proposed method, is given

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The EU began railway reform in earnest around the turn of the century. Two ‘railway packages’ have meanwhile been adopted amounting to a series of directives and a third package has been proposed. A range of complementary initiatives has been undertaken or is underway. This BEEP Briefing inspects the main economic aspects of EU rail reform. After highlighting the dramatic loss of market share of rail since the 1960s, the case for reform is argued to rest on three arguments: the need for greater competitiveness of rail, promoting the (market driven) diversion of road haulage to rail as a step towards sustainable mobility in Europe, and an end to the disproportional claims on public budgets of Member States. The core of the paper deals respectively with market failures in rail and in the internal market for rail services; the complex economic issues underlying vertical separation (unbundling) and pricing options; and the methods, potential and problems of introducing competition in rail freight and in passenger services. Market failures in the rail sector are several (natural monopoly, economies of density, safety and asymmetries of information), exacerbated by no less than 7 technical and legal barriers precluding the practical operation of an internal rail market. The EU choice to opt for vertical unbundling (with benefits similar in nature as in other network industries e.g. preventing opaque cross-subsidisation and greater cost revelation) risks the emergence of considerable coordination costs. The adoption of marginal cost pricing is problematic on economic grounds (drawbacks include arbitrary cost allocation rules in the presence of large economies of scope and relatively large common costs; a non-optimal incentive system, holding back the growth of freight services; possibly anti-competitive effects of two-part tariffs). Without further detailed harmonisation, it may also lead to many different systems in Member States, causing even greater distortions. Insofar as freight could develop into a competitive market, a combination of Ramsey pricing (given the incentive for service providers to keep market share) and price ceilings based on stand-alone costs might be superior in terms of competition, market growth and regulatory oversight. The incipient cooperative approach for path coordination and allocation is welcome but likely to be seriously insufficient. The arguments to introduce competition, notably in freight, are valuable and many e.g. optimal cross-border services, quality differentiation as well as general quality improvement, larger scale for cost recovery and a decrease of rent seeking. Nevertheless, it is not correct to argue for the introduction of competition in rail tout court. It depends on the size of the market and on removing a host of barriers; it requires careful PSO definition and costing; also, coordination failures ought to be pre-empted. On the other hand, reform and competition cannot and should not be assessed in a static perspective. Conduct and cost structures will change with reform. Infrastructure and investment in technology are known to generate enormous potential for cost savings, especially when coupled with the EU interoperability programme. All this dynamism may well help to induce entry and further enlarge the (net) welfare gains from EU railway reform. The paper ends with a few pointers for the way forward in EU rail reform.

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Vols. for -Apr. 1916 called new ser. and also old ser., v. -91.

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No. 141- also called v. 13-

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No numbers issued for Nov.-Dec. 1975

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Past studies resulted in conflicting definitions of consumer motivation. On the one hand, motivations are seen as the consumer’s characteristics that shape her general behavior (motivational trait). On the other hand, they are seen as contextual variables representing the reason why the individual is behaving specific to today’s context (motivational state). The objective of this research is to stress the difference between these two concepts and to understand the impact of each on consumer behavior. We applied our empirical study to shopping motivations; our results show a strong interaction between motivational trait and motivational state. Problem and Hypothesis On the one hand, Westbrook and Black (1985) consider shopping motivations as individual permanent characteristics. This concept is shared by other researchers (Rohm and Swaminathan 2004), which show that some shoppers are functional (they shop for convenience, information seeking, and time saving) while some others are hedonic (they shop for social interaction, bargain hunting and browsing). On the other hand, Kaltcheva and Weitz (2006) define motivations as a contextual orientation changing over time, depending on the situation, and show that contextual shopping motivations have a strong impact on shopping behavior. From our knowledge, no research specifically examined the respective impact of both these shopping motivation types. To deal with this issue, we used the notions of “traits” and “states” that have been largely used in marketing research to designate respectively a permanent characteristic of the individual and a temporary orientation of the consumer (Mowen 2000). The reversal theory (Apter 2001) suggests that two opposite states exist: the telic and the paratelic states. In the telic state, individuals set goals for themselves, must be disciplined to reach these goals, and do not behave in accordance with their personal trait. In the paratelic state, individuals are seeking arousal and enjoyment, do not set rules, and one could postulate that they act in accordance with their natural tendencies. Based on these considerations, we hypothesize the following process: in situations involving paratelic states, hedonic as well as functional individuals should behave according to their natural traits, whereas in situations involving telic states, hedonic people should inhibit their natural propensity to enjoy shopping and behave similarly to functional people. Hence, we postulate the following: Hypothesis: Compared to shoppers with functional motivational trait, shoppers with hedonic motivational trait will a) significantly display more hedonic shopping behavior intentions in a condition of paratelic motivational state, and b) not display more hedonic shopping behavior intentions in a condition a telic motivational state Empirical Research First, 108 participants were asked to fill a multi-items scale about their shopping habits, which actually measured their shopping motivational traits. This questionnaire allowed us to highlight four different dimensions in shopping motivational traits: social interaction, novelty/utility seeking, bargain hunting, and browsing. According to their scores on different items, participants were classified as functional or as hedonic on each of these four dimensions (a single individual may be hedonic on some dimensions and functional on others). Then, participants were then induced to adopt either a telic or a paratelic shopping motivational state while reading an appropriate scenario. Finally, participants were asked for their shopping behavior intentions in response to the shopping context. Four items were developed, corresponding to the four shopping motivational trait dimensions we found with our factor analysis. Results As we found four dimensions in shopping motivational trait, we set up four quasi-experimental designs to capture the entire phenomenon: for each dimension, a 2 (motivational trait) x 2 (motivational state) design was built, where the dependant variable was the shopping behavior element corresponding to the studied dimension. Four 2 x 2 Anovas were performed to assess the interaction between motivational trait and motivational state. Concerning the three dimensions - browsing, novelty/utility seeking, and bargain hunting- , in the paratelic state scenario participants with hedonic motivational trait displayed significantly more hedonic shopping behavior intentions than participants with a functional motivational trait (resp. F = 9.701, p = .003; F = 4.979, p = .03; F = 5.757, p = .02); and in the telic state scenario, there was no significant difference in behavior intentions between participants with hedonic or functional motivation trait. Each time, the interaction effect between motivational state and motivational trait was significant (resp. F = 4.859, p = .03; F = 3.314, p = .07; F = 2.98, p = .08). Concerning the fourth dimension, social interaction, shopping behavior intentions of participants with hedonic and with functional motivational traits were significantly different in the paratelic state scenario (F = 29.898, p <.000) as well as in the telic state scenario (F = 9.559, p = .003). However, the interaction effect showed that this behavioral difference was significantly stronger in the paratelic scenario. All these results support our research hypothesis. Discussion and Implications Our study provides consistent support for our hypotheses saying that there is an interaction effect between shopping motivational states and shopping motivational traits. The generalization of the results is strengthened by the study of four different shopping traits: social interaction, novelty/utility seeking, bargain hunting and browsing. As we proposed, when shopping in a goal-oriented state (telic state), behaviors of hedonic and functional shoppers do not differ significantly. Conversely, when shopping for a recreational reason (paratelic state), hedonic and functional shoppers behave significantly different. These results could explain why some previous studies concluded that shopping motivational traits had no impact on shopping behavior: they did not take into consideration the interaction between motivational trait and motivational state. Moreover, our study shows that marketing surveys performed by store managers to draw the personal profile of their customers must be crossed with contextual motivations in order to accurately forecast shopper behavior. Future Developments Our results can be explained by the self-control process, which pushes hedonic-trait shoppers to behave in a rather functional way in utilitarian situations. However, to be certain that this is the very process that occurs, we plan to add self-control perception scales to our existing measures. This is obviously the next step of this research.

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This paper considers the role of HR in ethics and social responsibility and questions why, despite an acceptance of a role in ethical stewardship, the HR profession appears to be reluctant to embrace its responsibilities in this area. The study explores how HR professionals see their role in relation to ethical stewardship of the organisation, and the factors that inhibit its execution. A survey of 113 UK-based HR professionals, working in both domestic and multinational corporations, was conducted to explore their perceptions of the role of HR in maintaining ethical and socially responsible action in their organisations, and to identify features of the organisational environment which might help or hinder this role being effectively carried out. The findings indicate that although there is a clear understanding of the expectations of ethical stewardship, HR professionals often face difficulties in fulfilling this role because of competing tensions and perceptions of their role within their organisations. A way forward is proposed, which draws on the positive individual factors highlighted in this research to explore how approaches to organisational development (through positive deviance) may reduce these tensions to enable the better fulfilment of ethical responsibilities within organisations. The involvement and active modelling of ethical behaviour by senior management, coupled with an open approach to surfacing organisational values and building HR procedures, which support socially responsible action, are crucial to achieving socially responsible organisations. Finally, this paper challenges the HR profession, through professional and academic institutions internationally, to embrace their role in achieving this. © 2013 Taylor & Francis.

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The concept of a substantive integrator is introduced as a method for integrated resource and environmental management as a means to assimilate different resource values at the operational or field level. A substantive integrator is a strategic management tool for integrating multiple uses into coprorate management regimes that traditionally manage for single values. Wildlife habitat management is presented as a substantive integrator for managing vegetation on electric utility power line corridors. A case study from northern British Columbia provides an example of wildlife habitat management as a means to integrate other resource values such as aesthetics, access and subsistence along British Columbia Hydro and Power Authority's transmission rights-of-way.

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This is an initial report of the PolyU SD part of the team to study Pre-fabricated Building Design and Construction Methodology and marks the completion of Phase 1. It follows our first notes prepared for the meeting on 2 February that identified some critical issues including future lifestyles, life expectancy of buildings, sustainability, size, flexibility and planning considerations. It is also an expansion of our presentation in Dongguan on 23 February. It is not a comprehensive survey of existing approaches or possible ways forward, but it has homed in on certain specific issues and does give specific examples to make the suggestions concrete. It is recommended that more comprehensive research be done to establish previous work and experience internationally. It is also recommended that more research be done on lifestyles as a preliminary to developing at least three concepts for evaluation before proceeding to the detailed design of one concept for full prototyping and market testing. The goal at this point is not to define a single direction but to suggest several future trajectories for further consideration. By the same token, this report is not intended as an exhaustive description of the considerable base of knowledge and ideas brought by the PolyU team to this exciting task. Before taking on an issue of this magnitude and importance in the definition of Hong Kong's future, one must carry out a thoughtful analysis of the issues at hand and an informed definition of paradigms, directions, goals and methods whereby our energies can be best used in the next steps. This report is the result of this analysis

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Literature addressing methodological issues in organisational research is extensive and multidisciplinary, encompassing debates about methodological choices, data-collection techniques, epistemological approaches and statistical procedures. However, little scholarship has tackled an important aspect of organisational research that precedes decisions about data collection and analysis – access to the organisations themselves, including the people, processes and documents within them. This chapter looks at organisational access through the experiences of three research fellows in the course of their work with their respective industry partners. In doing so, it reveals many of the challenges and changing opportunities associated with access to organisations, which are rarely explicitly addressed, but often assumed, in traditional methods texts and journal publications. Although the level of access granted varied somewhat across the projects at different points in time and according to different organisational contexts, we shared a number of core and consistent experiences in attempting to collect data and implement strategies.

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The Way-fi nding in the Built Environment project is a worldwide review identifying those way-fi nding systems and technologies that could be used to make it easier and safer for people with a sensory impairment (and in particular a vision impairment) to fi nd their way around buildings and large public spaces. The project makes recommendations on how these technologies and systems may be incorporated, by law or otherwise, into Australia’s building and construction practice. Way-fi nding aims to ensure that people with a sensory impairment know where they are in a building or an environment, where their desired location is, and how to get there from their present location. It is unlawful to discriminate against people with a disability under the Disability Discrimination Act 1992.

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Industrial employment growth has been one of the most dynamic areas of expansion in Asia; however, current trends in industrialised working environments have resulted in greater employee stress. Despite research showing that cultural values affect the way people cope with stress, there is a dearth of psychometrically established tools for use in non-Western countries to measure these constructs. Studies of the "Way of Coping Checklist-Revised" (WCCL-R) in the West suggest that the WCCL-R has good psychometric properties, but its applicability in the East is still understudied. A confirmatory factor analysis (CFA) is used to validate the WCCL-R constructs in an Asian population. This study used 1,314 participants from Indonesia, Sri Lanka, Singapore, and Thailand. An initial exploratory factor analysis revealed that original structures were not confirmed; however, a subsequent EFA and CFA showed that a 38-item, five-factor structure model was confirmed. The revised WCCL-R in the Asian sample was also found to have good reliability and sound construct and concurrent validity. The 38-item structure of the WCCL-R has considerable potential in future occupational stress-related research in Asian countries.

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Over the last decade in Australia, the role of the teacher has changed. Teachers are now expected to model and foster in their students a wide range of skills such as critical thinking, self-regulated learning, knowledge of self and others and lifelong learning. These changes are having a significant impact on the design of pre-service teacher education programmes, with university educators re-evaluating the teacher training curriculum and embedded pedagogical processes in order to consider how they might develop these skills in pre-service teachers. One approach is to consider the processes and practices inherent in philosophical inquiry. This paper reports on three participants’ reflections of a 12-week philosophy programme that was conducted for teacher educators at Queensland’s University of Technology (QUT) in 2008. The programme was facilitated by teachers from Buranda State School who have been teaching philosophy in their P-7 school for more than ten years. This paper provides insight into teacher educators’ reflections on the philosophy programme and the associated changes and challenges of implementing such a programme in pre-service teacher education degrees.