1,721,166 research outputs found
An analysis of the potential for on-track competition in the British passenger rail industry
No full textThis paper undertakes a systematic review of the potential for on-track competition in the passenger railway industry in Great Britain, and concludes that some such competition is likely. A simulation model is developed and tested on an inter-city rail line. The findings in respect of different forms of competition are examined. It is concluded that on-track competition is unlikely to promote economic efficiency unless it leads to cost reductions and/or product differentiation
Towards a checklist for identification of an atypical event scenario
No full textProper hazard identification in safety reports has become progressively more difficult to achieve. Several major incidents in Europe in recent years, such as Buncefield and Toulouse, were not even considered by their site Seveso II Safety Case. One of the reasons is that available hazard identification (HAZID) methodologies take no notice of least likely or unknown events. Non-identified scenarios thus constitute a latent risk, whose management is extremely complex and open-ended. Hence this work aims to investigate the issue of atypical scenarios and explain how they could have been identified.
An in-depth historical analysis of some of these incidents has been performed, in order to outline general features of plants in which they occurred, their causes, consequences and lessons learned. This analysis has followed a precise common scheme, which allowed a systematic approach to the problem. Based on the findings, failures connected to risk management and risk appraisal have been identified. Checklist questions and recommendations will be compiled, making efforts to improve the general safety of industry. Attempts will be made to review well-known HAZID methodologies, and thus the process of risk appraisal, with the purpose of improving the HAZID processes to identify atypical scenarios
The privatization of passenger rail services in Great Britain: an evaluation of competition for the market and competition in the market
No full textThe background to the research reported here is the reorganization and privatization of passenger rail services in Great Britain. This process, enacted by the 1993 Railway Act, made provision for competition in the supply of passenger rail services by fostering competition for the market through a process of franchising, and competition in the market by allowing for the possibility of on-track competition. The attempt to couple both forms of competition is novel and complex, and warrants investigation. In this paper we provide a background to the privatization process and report on the results of models that we have developed to predict and assess the outcome of off-track and on-track competition. On the basis we highlight the principal gains and losses brought about as a result of the regulatory changes and make some suggestions of how rail privatization could be improved
Holistic risk management of atypical accident scenarios
No full textSeveral of the major accidents that occurred in Europe in recent years showed unexpected scenarios not considered by their site safety reports, such as the accidents at Toulouse (France) in 2001 and Buncefield (United Kingdom) in 2005. This contribution tackles this emerging risk of “atypical” accident scenarios, not captured by standard risk assessment because deviating from normal expectations, which has been firstly introduced by the EC project iNTeg-Risk. A synergy of tools developed or used within the this project is adopted as way of prevention of atypical accident scenarios. Lessons learned, recommendations and the new methodology DyPASI (Dynamic Procedure for Atypical Scenarios Identification) is completed by the REWI (Resilience based Early Warning Indicators) method. The first technique is built for the identification of atypical scenarios and is based on systematization of information from early warnings, represented by past events, near misses and in-depth studies related to the industrial process considered. The second one is a proactive methodology for the development of resilience based early warning indicators and can unveil early deviations in the casual chain of potential accident scenarios. The composition of the two represents an advanced approach to tackle this topical issue from different slants for a more complete result. However, the core of the whole project is always kept as a reference point: the Emerging Risk Management Framework (ERMF), defined to provide the basis for integration of the research and management activities in the area of emerging risks.; ; This approach has been applied with the purpose to assess risk in new and emerging technologies, such as the cases of Carbon Capture and Sequestration or Liquid Natural Gas regasification, where relative lack of experience can possibly lead to atypical accident scenarios. The results produced are described in this contribution as demonstration of effectiveness of this new holistic approach
The demand for public transport: a practical guide
No full textThis document reports on the outcome of a collaborative study the objective of which was to produce an up-to-date guidance manual on the factors affecting the demand for public transport for use by public transport operators and planning authorities, and for academics and other researchers. The context of the study was principally that of urban surface transport in Great Britain, but extensive use is made of international sources and examples. Analysis and research by using primary and secondary data sources on the influencing factors were pursued to produce a document that assists in identifying cost-effective schemes for improving services. A wide range of factors was examined. The study has re-examined the evidence from an earlier, 1980, study on the factors affecting the demand for public transport, and has extended the coverage from that of the 1980 study to reflect the changing sociological and policy background
Dypasi Methodology: from Information Retrieval to Integration of Hazid Process
No full textThe availability of hazard identification methodologies based on early warnings is a crucial factor in the prevention of major accidents. Accidents like Seveso, Buncefield and Toulouse, where severe consequences occurred seemingly unexpected by the plant safety management, have made it clear that a comprehensive and complete identification and assessment of potential hazards in the process industry are of primary importance for the prevention and the mitigation of accident scenarios. The accident scenarios deviating from normal expectations of unwanted events or worst-case reference scenarios captured by common HAZard IDentification (HAZID) techniques are usually defined as “atypical”. The main issue posed by the prevention of atypical scenarios is the availability of techniques able to identify them within a routine HAZID process, capturing evidence of new hazards and learning from ‘early warnings’ as soon as they come to light. For this reason a specific method named Dynamic Procedure for Atypical Scenarios Identification (DyPASI) was developed. The method was conceived as a development of conventional bow-tie identification techniques. DyPASI is a method for the continuous systematization of information from early signals of risk related to past events. It dynamically integrates in the bow-ties the results of information retrieval activities. DyPASI features as a tool to support emerging risk management process, having the potentiality to contribute to an integrated approach aimed at breaking “vicious circles”, helping to trigger a gradual process of identification and assimilation of previously unrecognized atypical scenarios. The current contribution presents the technique and demonstrates the application by a selected case-study of practical application (Toulouse AZF accident, Buncefield oil depot accident, LNG regasification terminal, CCS plant)
Demand Forecasting for New Local Rail Services: A Case Study of a New Service Between Leicester and Burton-On- Trent
Get PDFPreston, J. and Wardman, M. (1988) "Demand Forecasting for New
Local Rail Services: A Case Study of a New Service between
Leicester and Burton-on-Trent". Workina Paver 260, Institute for
Transport Studies, University of Leeds.
This paper assesses the potential for a new rail service between
Leicester and Burton-on-rent. In order to do this, three sets of
demand forecasts were produced. These were based on Revealed
Preference (RP) models that had been developed in West Yorkshire,
a Stated Intentions (SI) survey of the Leicester-Burton corridor
and Stated Preference (SP) models developed for the Ashby/
Coalville -and Outer Leicester areas. It was found that these
three approaches gave a wide range of forecasts but it was felt
that the SI survey, adjusted for the findings from the SP models,
were likely to give the most reliable estimates of usage. As a
result, it was concluded that, given patronage growth over time,
total usage of the line would amount to between 3,000 and 4,000
trips on an average day.
The demand forecasts were then used as input to an evaluation
framework which took into account capital costs, operating costs,
revenue and time savings. Even if actual usage reached the upper
level of our forecasts it was shown that, although operating
costs would be covered, only some of the capital costs would be
paid back. Consideration of user time savings strengthens the
case for the scheme but even so a return on capital would still
not be achieved. Therefore, it was concluded that the case for a
rail service between Leicester and Burton is, at best, marginal,
although a number of ways to continue the feasibility study are
suggested
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
