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作者：Atamtürk, A; Küçükyavuz, S
作者单位：University of California System; University of California Berkeley
摘要：We investigate the polyhedral structure of the lot-sizing problem with inventory bounds. We consider two models, one with linear cost on inventory, the other with linear and fixed costs on inventory. For both models, we identify facet-defining inequalities that make use of the inventory bounds explicitly and give exact separation algorithms. We also describe a linear programming formulation of the problem when the order and inventory costs satisfy the Wagner-Whitin nonspeculative property. We ...
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作者：Lim, A; Rodrigues, B
作者单位：Hong Kong University of Science & Technology; Singapore Management University
摘要：Huang et al. (2003) used the Cesaro limit of a savings function to determine the optimal special order in an EOQ model with single announced price increases over an infinite horizon. In this note, we point out that the savings function is not Cesaro summable. More importantly, no limiting argument for the cost function d(t, Q(s)) as t -> infinity is necessary at all given that this function is periodic for which it suffices to optimize the integral of the function over any given period.
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作者：Paul, A
作者单位：State University System of Florida; University of Florida
摘要：Increasing generalized failure rate (IGFR) distributions were introduced as a tool in the study of contracting mechanisms in supply chains. In this note, we compare and contrast the closure-and the lack thereof-of IGFR and increasing failure rate (IFR) distributions with respect to standard operations on random variables. Some implications of these results for the use of IGFR distributions in supply chain models are noted.
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作者：den Boef, E; Korst, J; Martello, S; Pisinger, D; Vigo, D
作者单位：Philips; Philips Research; University of Bologna; University of Copenhagen
摘要：In the three-dimensional bin packing problem the task is to orthogotnally pack a given set of rectangular items into a minimum number of three-dimensional rectangular bins. We give a characterization of the algorithm proposed by Martello et al. (2000) for the exact solution of the problem, showing that not all orthogonal packings can be generated by the proposed algorithm. the packings, however, have the property,of being robot, packings, which is relevant in practical settings. References to ...
