355 research outputs found

    AC railway electrification systems - An EMC perspective

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    Railways are electrified in many different ways. In this article, the main options for electrifying a high speed AC railway are reviewed from an electromagnetic compatibility (EMC) perspective. Firstly, the trend of increasing the usage of electrified trains to replace conventional diesel locomotives is pointed out. On this basis, the significance of considering EMC in the railway environment is explained, with a view to preventing the malfunction of the railway system. Secondly, different electrification options are introduced, namely the rail-return, booster-transformer and auto-transformer systems. The benefits and drawbacks of each electrification option are considered based on the interference level to the trackside railway signaling and telecommunication systems. The discussion of each electrification system is verified using electromagnetic simulations. By comparing the different electrification schemes, it is shown that the auto-transformer system has better EMC performance and delivers higher power to the train

    Exploring Perspectives of the Validity, Legitimacy and Acceptability of Environmental Valuation using Q Methodology

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    The extension of market systems and economic appraisal methods to the natural world and allocation of scarce resources is highly controversial and viewed by some as unethical. This has resulted in questions about the appropriate role of valuation and appraisal methods in informing policy and decision-making. We address this issue by assessing the different points of view that exist in marine research, management and policy communities regarding the estimation of monetary values for marine ecosystems and services and their use in appraisal and policy settings. The principal perspectives emerging from a Q-sort survey of x respondents reveal a clear distinction between a group that is highly sceptical of the framing of human-environment relations in terms of ecosystem services and of the use of economic appraisal and valuation tools in this context, and two or three other groups that are broadly favourable towards that paradigm and its methods, but with slightly different reasons for supporting valuation in practice. Despite the distinguishing features, areas of consensus emerge, including a strong shared perspective that places avoiding damage to marine biodiversity and ecosystems as a fundamental obligation. Furthermore, it is shown that the sceptics do not entirely reject valuation out of hand, but rather express understandable concerns about applicability and appropriate uses that are to some extent recognised by the pro-valuation groups

    Exploring Perspectives of the Validity, Legitimacy and Acceptability of Environmental Valuation using Q Methodology

    Get PDF
    The extension of market systems and economic appraisal methods to the natural world and allocation of scarce resources is highly controversial and viewed by some as unethical. This has resulted in questions about the appropriate role of valuation and appraisal methods in informing policy and decision-making. We address this issue by assessing the different points of view that exist in marine research, management and policy communities regarding the estimation of monetary values for marine ecosystems and services and their use in appraisal and policy settings. The principal perspectives emerging from a Q-sort survey of x respondents reveal a clear distinction between a group that is highly sceptical of the framing of human-environment relations in terms of ecosystem services and of the use of economic appraisal and valuation tools in this context, and two or three other groups that are broadly favourable towards that paradigm and its methods, but with slightly different reasons for supporting valuation in practice. Despite the distinguishing features, areas of consensus emerge, including a strong shared perspective that places avoiding damage to marine biodiversity and ecosystems as a fundamental obligation. Furthermore, it is shown that the sceptics do not entirely reject valuation out of hand, but rather express understandable concerns about applicability and appropriate uses that are to some extent recognised by the pro-valuation groups

    Prospects for Valuation in Marine Decision Making in Europe

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    There is now high-level recognition that the UN Sustainable Development Goals can only be achieved if the decline of ecosystems and biodiversity can be halted and reversed. This will require effective control of ongoing pressures, meaningful protection and enforcement of protected areas, and significant investments in ecosystem restoration. This paper explores the possible use of economic valuation and appraisal in achieving these goals in marine systems and discusses the European marine policy instruments where they should have an important role The paper first briefly reviews the tools of economic valuation and appraisal for marine ecosystem management. A critique of the use of economic valuation and appraisal in marine conservation and restoration is then presented. The paper argues that while progress has been made there remains a pressing need for better integration of marine environmental values in policy processes. It also highlights the fact that the focus on natural capital accounting, and more generally on green/blue growth and market instruments, could create a reliance on exchange values at the expense of welfare values required for policy appraisal

    Practices for strategic capacity management in Malaysian manufacturing firms

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    While the notion of manufacturing capabilities is a long-standing notion in research on operations management, its actual implementation and management has been hardly researched. Five case studies in Malaysia offered the opportunity to examine the practice of manufacturing managers with regard to strategic capability management. The data collection and analysis was structured by using the notion of Strategic Capacity Management. Whereas traditionally literature has demonstrated the beneficial impact of an appropriate manufacturing strategy on the business strategy and performance, the study highlights the difficulty of managers to set the strategy, let alone implementing it. This is partly caused by the immense pressure of customers in these dominantly Make-To-Order environments for SMEs. Current concepts for manufacturing capabilities have insufficiently accounted this phenomenon and an outline of a research agenda is presented

    Hows and whys of artificial intelligence for public sector decisions: Explanation and evaluation

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    Evaluation has always been a key challenge in the development of artificial intelligence (AI) based software, due to the technical complexity of the software artifact and, often, its embedding in complex sociotechnical processes. Recent advances in machine learning (ML) enabled by deep neural networks has exacerbated the challenge of evaluating such software due to the opaque nature of these ML-based artifacts. A key related issue is the (in)ability of such systems to generate useful explanations of their outputs, and we argue that the explanation and evaluation problems are closely linked. The paper models the elements of a ML-based AI system in the context of public sector decision (PSD) applications involving both artificial and human intelligence, and maps these elements against issues in both evaluation and explanation, showing how the two are related. We consider a number of common PSD application patterns in the light of our model, and identify a set of key issues connected to explanation and evaluation in each case. Finally, we propose multiple strategies to promote wider adoption of AI/ML technologies in PSD, where each is distinguished by a focus on different elements of our model, allowing PSD policy makers to adopt an approach that best fits their context and concerns.Comment: Presented at AAAI FSS-18: Artificial Intelligence in Government and Public Sector, Arlington, Virginia, USA; corrected typos in this versio

    Prospects for Valuation in Marine Decision Making in Europe

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    There is now high-level recognition that the UN Sustainable Development Goals can only be achieved if the decline of ecosystems and biodiversity can be halted and reversed. This will require effective control of ongoing pressures, meaningful protection and enforcement of protected areas, and significant investments in ecosystem restoration. This paper explores the possible use of economic valuation and appraisal in achieving these goals in marine systems and discusses the European marine policy instruments where they should have an important role The paper first briefly reviews the tools of economic valuation and appraisal for marine ecosystem management. A critique of the use of economic valuation and appraisal in marine conservation and restoration is then presented. The paper argues that while progress has been made there remains a pressing need for better integration of marine environmental values in policy processes. It also highlights the fact that the focus on natural capital accounting, and more generally on green/blue growth and market instruments, could create a reliance on exchange values at the expense of welfare values required for policy appraisal.publishedVersio

    Prospects for Valuation in Marine Decision Making in Europe

    Get PDF
    There is now high-level recognition that the UN Sustainable Development Goals can only be achieved if the decline of ecosystems and biodiversity can be halted and reversed. This will require effective control of ongoing pressures, meaningful protection and enforcement of protected areas, and significant investments in ecosystem restoration. This paper explores the possible use of economic valuation and appraisal in achieving these goals in marine systems and discusses the European marine policy instruments where they should have an important role The paper first briefly reviews the tools of economic valuation and appraisal for marine ecosystem management. A critique of the use of economic valuation and appraisal in marine conservation and restoration is then presented. The paper argues that while progress has been made there remains a pressing need for better integration of marine environmental values in policy processes. It also highlights the fact that the focus on natural capital accounting, and more generally on green/blue growth and market instruments, could create a reliance on exchange values at the expense of welfare values required for policy appraisal
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