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作者：Brimberg, J; Juel, H; Schöbel, A
作者单位：University of Prince Edward Island; Universite de Montreal; HEC Montreal; Technical University of Denmark; University of Kaiserslautern
摘要：We consider the problem of locating a line or a line segment in three-dimensional space, such that the sum of distances from the facility represented by the line (segment) to a given set of points is minimized. An example is planning the drilling of a mine shaft, with access to ore deposits through horizontal tunnels connecting the deposits and the shaft. Various models of the problem are developed and analyzed, and efficient solution methods are given.
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作者：Chan, LMA; Muriel, A; Shen, ZJ; Simchi-Levi, D
作者单位：University of Toronto; University of Massachusetts System; University of Massachusetts Amherst; State University System of Florida; University of Florida; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT)
摘要：We consider an economic lot-sizing problem with a special class of piecewise linear ordering costs, which we refer to as the class of modified all-unit discount cost functions. Such an ordering cost function represents transportation costs charged by many less-than-truckload carriers. We show that even special cases of the lot-sizing problem are NP-hard and therefore analyze the effectiveness of easily implementable policies. In particular, we demonstrate that there exists a zero-inventory-ord...
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作者：Gerchak, Y; He, QM; Fuller, JD; Chungcharoen, E
作者单位：Tel Aviv University; Dalhousie University; University of Waterloo; Thammasat University
摘要：Consider a basin with remaining undiscovered fields, in which both field sizes and their number are uncertain. Assuming that the probability of finding a field is increasing in its size, we show that the expected size of the first remaining field discovered, which is of particular importance, is increasing in the variability of field sizes, and results from a simulation model of exploration illustrate this trend for the first several fields discovered. We also provide simple bounds on the expe...
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作者：L'ecuyer, P; Simard, R; Chen, EJ; Kelton, WD
作者单位：Universite de Montreal; BASF; University System of Ohio; University of Cincinnati
摘要：Multiple independent streams of random numbers are often required in simulation studies, for instance, to facilitate synchronization for variance-reduction purposes, and for making independent replications. A portable set of software utilities is described for uniform random-number generation. It provides for multiple generators (streams) running simultaneously, and each generator (stream) has its sequence of numbers partitioned into many long disjoint contiguous substreams. The basic underlyi...
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作者：Rajaram, K; Corbett, CJ
作者单位：University of California System; University of California Los Angeles
摘要：Large scale industrial production processes face increasingly tight environmental constraints, which can be addressed through costly but relatively simple end-of-pipe solutions or through cheaper but more subtle pollution prevention approaches Achieving the process improvements necessary for pollution prevention is challenging due to the inherent complexity and unpredictability of several types of processes found in the food processing pharmaceuticals biotechnology and specialty chemical indus...
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作者：Barker, HG III; Calabrese, DA; Fischer, MJ; Garbin, DA; Knepley, JE; Swinsky, GW
摘要：The Defense Information System Agency (DISA) has managerial and engineering responsibility for a circuit switched network currently known as the Defense Information System Network-Voice This network was originally implemented in the 1960s and was known as the Automatic Voice Network Throughout this time DISA has used a network design and analysis model to reconfigure the network This model was developed in the early 1970s has been continually enhanced and is used on a weekly basis to engineer ...
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作者：Alpern, S
作者单位：University of London; London School Economics & Political Science
摘要：The rendezvous search problem was posed by the author 25 years ago In its basic form it asks how two unit speed players can find each other in least expected time when randomly placed in a known dark region The problem received little attention until about 10 years ago This article surveys the rapid progress that has been made since then and also presents some new results.
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作者：Smith, JE; McCardle, KF
作者单位：Duke University; University of California System; University of California Los Angeles
摘要：In Markov models of sequential decision processes one is often interested in showing that the value function is monotonic convex and/or supermodular in the state variables These kinds of results can be used to develop a qualitative understanding of the model and characterize how the results will change with changes in model parameters In this paper we present several fundamental results for establishing these kinds of properties The results are in essence metatheorems showing that the value fu...
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作者：Owen, JH; Mehrotra, S
作者单位：General Motors; Northwestern University
摘要：We study the use of binary variables in reformulating general mixed integer linear programs We show that binary reformulations result in problems for which almost all the binary variables replacing a general integer variable need to be explored during branching We also give computational results on the performance of such reformulations in solving the mixed integer programs which support our theoretical results.
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作者：Ghosh, S; Henderson, SG
作者单位：Cornell University
摘要：There is a growing need for the ability to specify and generate correlated random variables as primitive inputs to stochastic models Motivated by this need several authors have explored the generation of random vectors with specified marginals together with a specified covariance matrix through the use of a transformation of a multivariate normal random vector (the NORTA method) A covariance matrix is said to be feasible for a given set of marginal distributions if a random vector exists with ...
