406,953 research outputs found

    Divine Contingency

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    Contingency planning in southern Africa: Events rather than processes?

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    With the increasing frequency, magnitude and impact of disasters, there is growing focus on contingency planning as a tool for enhancing resilience. Yet, there is little empirical evidence that reflects on the practice of contingency planning systems within the context of disaster risk reduction. This article explores the practice of contingency planning in southern Africa, focussing on Malawi, Mozambique, Namibia, Zambia and Zimbabwe. A qualitative comparative analysis informed by fieldwork was used. The findings show that (1) there was a wide gap between theory and practice in contingency planning, (2) response activities rarely reflected projected scenarios and (3) resources were inadequate for effective contingency planning. We conclude that unless these issues are addressed, contingency planning is likely o remain a theoretical rather than a practical tool for building disaster-resilient communities in southern African countries. Although a generalisation cannot be made on the status of contingency planning and practice in southern Africa without a wider analysis of more examples, the findings may apply beyond the examined contexts and also offer insights into research gaps

    Complete contingency planners

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    A framework is proposed for the investigation of planning systems that must deal with bounded uncertainty. A definition of this new class of contingency planners is given. A general, complete contingency planning algorithm is described. The algorithm is suitable to many incomplete information games as well as planning situations where the initial state is only partially known. A rich domain is identified for the application and evaluation of contingency planners. Preliminary results from applying our complete contingency planner to a portion of this domain are encouraging and match expert level performance

    Contingency-Constrained Unit Commitment with Post-Contingency Corrective Recourse

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    We consider the problem of minimizing costs in the generation unit commitment problem, a cornerstone in electric power system operations, while enforcing an N-k-e reliability criterion. This reliability criterion is a generalization of the well-known NN-kk criterion, and dictates that at least (1−ej)(1-e_ j) fraction of the total system demand must be met following the failures of kk or fewer system components. We refer to this problem as the Contingency-Constrained Unit Commitment problem, or CCUC. We present a mixed-integer programming formulation of the CCUC that accounts for both transmission and generation element failures. We propose novel cutting plane algorithms that avoid the need to explicitly consider an exponential number of contingencies. Computational studies are performed on several IEEE test systems and a simplified model of the Western US interconnection network, which demonstrate the effectiveness of our proposed methods relative to current state-of-the-art

    Responsibility modelling for civil emergency planning

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    This paper presents a new approach to analysing and understanding civil emergency planning based on the notion of responsibility modelling combined with HAZOPS-style analysis of information requirements. Our goal is to represent complex contingency plans so that they can be more readily understood, so that inconsistencies can be highlighted and vulnerabilities discovered. In this paper, we outline the framework for contingency planning in the United Kingdom and introduce the notion of responsibility models as a means of representing the key features of contingency plans. Using a case study of a flooding emergency, we illustrate our approach to responsibility modelling and suggest how it adds value to current textual contingency plans

    Fear expression and return of fear following threat instruction with or without direct contingency experience

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    Prior research showed that mere instructions about the contingency between a conditioned stimulus (CS) and an unconditioned stimulus (US) can generate fear reactions to the CS. Little is known, however, about the extent to which actual CS US contingency experience adds anything beyond the effect of contingency instructions. Our results extend previous studies on this topic in that it included fear potentiated startle as an additional dependent variable and examined return of fear (ROF) following reinstatement. We observed that CS US pairings can enhance fear reactions beyond the effect of contingency instructions. Moreover, for all measures of fear, instructions elicited immediate fear reactions that could not be completely overridden by subsequent situational safety information. Finally, ROF following reinstatement for instructed CS+s was unaffected by actual experience. In summary, our results demonstrate the power of contingency instructions and reveal the additional impact of actual experience of CS US pairings
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