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This article explores the relationship between ethnic representation in security sector institutions and perceptions of safety. While most studies on post-conflict institutional reform focus on national institutions and outcomes, this article argues that a more nuanced view on ethnic representation is fruitful in order to account for the everyday perceptions of local people. Drawing on post-conflict Kosovo, the article analyzes how the representation of ethnic minorities in security institutions affects perceptions of safety among individuals across Kosovo’s municipalities. It also analyzes original interview data collected in the Pristina and Mitrovica municipalities that are typical cases of our sample. Both approaches validate that those municipalities that have ethnically representative security institutions also have higher levels of perceived safety. 相似文献
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In this article we investigate situations where the buyer is offered discounted price schedules from alternative vendors. Given various discount schedules, the buyer must make the best buying decision under a variety of constraints, such as limited storage space and restricted inventory budgets. Solutions to this problem can be utilized by the buyer to improve profitability. EOQ models for multiple products with all-units discounts are readily solvable in the absence of constraints spanning the products. However, constrained discounted EOQ models lack convenient mathematical properties. Relaxing the product-spanning constraints produces a dual problem that is separable, but lack of convexity and smoothness opens the door for duality gaps. In this research we present a set of algorithms that collectively find the optimal order vector. Finally, we present numerical examples using actual data. to illustrate the application of the algorithms. © 1993 John Wiley & Sons, Inc. 相似文献
46.
Craig C. Sherbrooke 《海军后勤学研究》1992,39(1):29-40
We develop approximations to estimate the expected backorders in a multiechelon system in which lateral supply actions between bases are allowed when a backorder occurs. These approximations are easy to compute, and the average absolute error over a wide range of parameter values is less than 4% when items are depot repairable, even when bases are dissimilar. With lateral supply, backorder reductions of 30-50% are not uncommon, and a 72% reduction was observed in two cases. Lateral supply becomes more important with low demand rates. A similar approach was unsuccessful for base-repairable items. However, lateral supply has a beneficial effect only when the lateral supply time is very short, 1/4 or less of the average base repair time. Even in such cases lateral supply is unlikely to be important in an actual application, because base management can expedite repair of critical items. 相似文献
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We show that the deterministic nonpreemptive scheduling problem with earliness and tardiness penalties can be solved in polynomial time for certain forms of an objective function provided that a certain optimization problem can be solved. We give instances where this problem has a solution and show that this generalizes several results from the literature. These results do not require symmetric penalization and the penalty functions need only be lower semicontinuous. 相似文献
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John W. Chinneck 《海军后勤学研究》1992,39(4):531-543
Nonviable network models have edges which are forced to zero flow simply by the pattern of interconnection of the nodes. The original nonviability diagnosis algorithm [4] is extended here to cover all classes of network models, including pure, generalized, pure processing, nonconserving processing, and generalized processing. The extended algorithm relies on the conversion of all network forms to a pure processing form. Efficiency improvements to the original algorithm are also presented. 相似文献
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We study a class of replacement models for systems subject to deterioration. The objective is to determine an optimal replacement policy that minimizes the average operating costs of the system. We use a parametric analysis to establish sufficient conditions for the optimality of control limit policies. This work generalizes several existing results for optimal replacement models in the literature. © 1992 John Wiley & Sons, Inc. 相似文献
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We consider a one-machine scheduling problem with earliness and tardiness penalties. All jobs are assigned a common due date and the objective is to minimize the total penalty due to job earliness and tardiness. We are interested in finding the optimal combination of the common due-date value and the job sequence. Despite the fact that this problem in general is very hard to solve, we prove that there exists at least a common property for all optimal solutions: The first job in an optimal sequence is one of the longest jobs. We also prove that this property holds for a general class of unimodal penalty functions. 相似文献