Protection Assessment using Reduced Power System Fault Data

Wavelet transforms provide basis functions for time-frequency analysis and have properties that are particularly useful for the compression of analogue point on wave transient and disturbance power system signals. This paper evaluates the compression properties of the discrete wavelet transform using actual power system data. The results presented in the paper indicate that reduction ratios up to 10:1 with acceptable distortion are achievable. The paper discusses the application of the reduction method for expedient fault analysis and protection assessment.

Substitutes for legal protection: corporate governance and dividends in Victorian Britain

Companies in Victorian Britain operated in a laissez-faire legal environment from the perspective of outside investors, implying that such investors were not protected by the legal system. This article seeks to identify the alternative mechanisms that outside shareholders used to protect themselves by examining the dividend policy and governance of over 800 publicly traded companies at the beginning of the 1880s. We assess the importance of these mechanisms by estimating their impact on Tobin's Q. Our evidence suggests that dividends and well-structured and incentivized boards of directors may have played a role in protecting the interests of outside investors.

Translating policy into practice: A case study in the secondary prevention of coronary heart disease

Background: This paper focuses on the relationships between health ‘policy’ as it is embodied in official documentation, and health ‘practice’ as reported and reflected on in the talk of policy makers, health professionals and patients. The specific context for the study involves a comparison of policies relating to the secondary prevention of coronary heart disease (CHD) in the two jurisdictions of Ireland – involving as they do a predominantly state funded (National Health Service) system in the north and a mixed healthcare economy in the south. The key question is to determine how the rhetoric of health policy as contained in policy documents connects to, and gets translated into practice and action.

Methods: The data sources for the study include relevant healthcare policy documents (N=5) and progress reports (N=6) in the two Irish jurisdictions, and semi-structured interviews with a range of policy-makers (N=28), practice nurses (14), general practitioners (12) and patients (13) to explore their awareness of the documents’ contents and how they saw the impact of ‘policy’ on primary care practice.

Results: The findings suggest that although strategic policy documents can be useful for highlighting and channelling attention to health issues that require concerted action, they have little impact on what either professionals or lay people do.

Conclusion: To influence the latter and to encourage a systematic approach to the delivery of health care it seems likely that contractual arrangements – specifying tasks to be undertaken and methods for monitoring and reporting on activity - are required.

Evaluating Train Protection Systems

This paper arose from the work carried out for the Cullen/Uff Joint Inquiry into Train Protection Systems. It is concerned with the problem of evaluating the benefits of safety enhancements in order to avoid rare, but catastrophic accidents, and the role of Operations Research in the process. The problems include both input values and representation of outcomes. A key input is the value of life. This paper briefly discusses why the value of life might vary from incident to incident and reviews alternative estimates before producing a 'best estimate' for rail. When the occurrence of an event is uncertain, the normal method is to apply a single 'expected' value. This paper argues that a more effective method of representing such situations is through Monte-Carlo simulation and demonstrates the use of the methodology on a case study of the decision as to whether or not advanced train protection (ATP) should have been installed on a route to the west of London. This paper suggests that the output is more informative than traditional cost-benefit appraisals or engineering event tree approaches. It also shows that, unlike the results from utilizing the traditional approach, the value of ATP on this route would be positive over 50% of the time.