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作者：Aggarwal, CC; Orlin, JB; Tai, RP
作者单位：Massachusetts Institute of Technology (MIT)
摘要：We propose a knowledge-based crossover mechanism for genetic algorithms that exploits the structure of the solution rather than its coding. More generally, we suggest broad guidelines for constructing the knowledge-based crossover mechanisms. This technique uses an optimized crossover mechanism, in which the one of the two children is constructed in such a way as to have the best objective function value from the feasible set of children, while the other is constructed so as to maintain the di...
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作者：Resnick, S; Samorodnitsky, G
作者单位：Cornell University
摘要：We discuss how long-range dependence can influence the characteristics of a single server queue. We take the analogue of the G/M/1 queue except that the input stream is altered to exhibit long-range dependence. The equilibrium queue size and equilibrium waiting time distributions have heavy tails. By suitably selecting the parameters of the inputs, the queue size or waiting time can be made to possess infinite variance and even infinite mean. Some simulations dramatically illustrate the potent...
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作者：Glasserman, P
摘要：We develop bounds and approximations for setting base-stock levels in production-inventory systems Kith limited production capacity. Our approximations become exact as inventories become critical, meaning either that the target service level is very high or the backorder penalty is very large. Our bounds apply even without this requirement. Wt consider both single-stage and multi-stage systems. For single-stage systems, we find tight bounds and asymptotically exact approximations for optimal b...
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作者：Samaratunga, C; Sethi, SP; Zhou, XY
作者单位：University of Toronto; Chinese University of Hong Kong
摘要：This paper is concerned with near-optimal control of manufacturing systems consisting of two unreliable machines in tandem and having the objective of minimizing the total discounted cost of inventories/shortages over an infinite horizon. Asymptotic optimal feedback controls are constructed with respect to the rate of machine breakdown/repair as compared to the given discount rate. Performance of these controls, known as hierarchical controls, is compared with the optimal cost (when possible) ...
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作者：Chen, FR; Zheng, YS
作者单位：University of Pennsylvania
摘要：We consider a distribution system with a central warehouse and multiple retailers. The warehouse orders from an outside supplier and replenishes the retailers which in turn satisfy customer demand. The retailers are nonidentical, and their demand processes are independent compound Poisson. There are economies of scale in inventory replenishment, which is controlled by an echelon-stock, batch-transfer policy. For the special case with simple Poisson demand, we develop an exact method for comput...
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作者：Williamson, DP; Hall, LA; Hoogeveen, JA; Hurkens, CAJ; Lenstra, JK; Sevastjanov, SV; Shmoys, DB
作者单位：Johns Hopkins University; Eindhoven University of Technology; Cornell University; Centrum Wiskunde & Informatica (CWI)
摘要：We consider the open shop, job shop, and flow shop scheduling problems with integral processing times. We give polynomial-time algorithms to determine if an instance has a schedule of length at most 3, and show that deciding if there is a schedule of length at most 4 is NP-complete. The latter result implies that, unless P = NP. there does not exist a polynomial-time approximation algorithm for any of these problems that constructs a schedule with length guaranteed to be strictly less than 5/4...
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作者：Bramel, J; SimchiLevi, D
作者单位：Northwestern University
摘要：The Vehicle Routing Problem with Time Windows (VRPTW) is one of the most important problems in distribution and transportation. A classical and recently popular technique that has proven effective for solving these problems is based on formulating them as a set covering problem. The method starts by solving its linear programming relaxation, via column generation, and then uses a branch and bound strategy to find an integer solution to the set covering problem: a solution to the VRPTW. An empi...
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作者：De, P; Dunne, EJ; Ghosh, JB; Wells, CE
作者单位：Ihsan Dogramaci Bilkent University
摘要：This note addresses the discrete version of the well-known time-cost tradeoff problem for project networks, which has been studied previously in the standard project management literature as well as in the related literature on Decision-CPM, All the algorithms proposed thus far for the solution of the general problem exhibit exponential worst-case complexity, with the notable exception of the pseudo-polynomial dynamic program due to Hindelang and Muth. We first demonstrate that this algorithm ...
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作者：Deichtmann, JM; Sainfort, F
摘要：Dyer and Sarin (1979) proposed an important generalization of the additive-multiplicative decomposition theorem for von; Neumann-Morgenstern (vNM) utility functions to measurable value functions based on the cardinality property of measurable value functions. However, because of a difference between the cardinality of measurable Value functions and the cardinality of vNM utility functions, an additional technical condition is needed, and presented here, for the decomposition theorem to hold.
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作者：Sharifnia, A
摘要：We demonstrate the instability of the ''join-the-shortest-queue'' routing policy and the ''first-come-first-served'' dispatching policy for a multiclass single-station queuing system with multiple nonidentical servers. Although instability is demonstrated in a deterministic setting, we have found strong evidence that it is not limited to this setting. The phenomenon that leads to instability is different from the one reported recently in the literature for nonacyclic systems, namely, servers s...
