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作者：DADA, M; MARCELLUS, R
摘要：We study the control of a production process which moves at a random time from an in-control state to an out-of-control state where an increased number of defective units is produced. After each unit is produced, a decision maker has three choices: continue production, invest in routine maintenance that restores the process to control, and invest in a more expensive learn maintenance that, in addition, may decrease the tendency of the process to go out of control. The optimal policy structure ...
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作者：VEATCH, MH; WEIN, LM
作者单位：Massachusetts Institute of Technology (MIT)
摘要：A manufacturing facility consisting of two stations in tandem operates in a make-to-stock mode: After production, items are placed in a finished goods inventory that services an exogenous Poisson demand. Demand that cannot be met from inventory is backordered. Each station is modeled as a queue with controllable production rate and exponential service times. The problem is to control these rates to minimize inventory holding and backordering costs. Optimal controls are computed using dynamic p...
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作者：FU, MC
摘要：For (s, S) inventory systems, we derive sample path derivatives of performance measures with respect to the two Parameters s and S. These derivatives yield derivative estimators which can be estimated from a single sample path or simulation of the inventory system, in some cases not even requiring actual knowledge of the underlying demand distribution. Such derivative estimates would be useful in sensitivity analysis or in gradient-based optimization techniques. We consider the nondiscounted p...
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作者：HLYNKA, M; STANFORD, DA; POON, WH; WANG, T
作者单位：Western University (University of Western Ontario); University of Alberta
摘要：We consider a queueing system with two servers, each with its own queue. The interarrival times are generally distributed. The service time for each server is exponentially distributed but the rates may be different. No jockeying between the two queues is allowed. We consider situations in which a smart customer can delay joining a queue until some arrivals or service departures have been observed. All other customers join the shortest queue. We find conditions under which the smart customer c...
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作者：GEORGIADIS, L; VINIOTIS, I
作者单位：North Carolina State University
摘要：We consider a multiclass GI/G/I queueing system, operating under an arbitrary work-conserving scheduling policy pi. We derive an invariance relation for the Cesaro sums of waiting times under pi, which does not require the existence of limits of the Cesaro sums. This allows us to include important classes in the set of admissible policies such as time-dependent and adaptive policies. For these classes of policies, ergodicity is not known a priori and may not even exist. Therefore, the classica...
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作者：ADVE, VS; NELSON, R
作者单位：International Business Machines (IBM); IBM USA
摘要：We consider an M/G/I queue with feedback, in which customers, after receiving service, either return to the tail of the queue or depart the system, according to some feedback policy. We derive simple expressions for the expected response time for feedback policies that include Bernoulli feedback and feeding back a fixed number of times. Our results reveal some interesting and nonintuitive properties of the behavior of such feedback policies when the coefficient of variation of service time is ...
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作者：NEMHAUSER, GL
作者单位：University System of Georgia; Georgia Institute of Technology
摘要：In the last decade, new advances in algorithms have been as important as the impressive advances in computer technology. Using the new interior-point algorithms and advanced implementations of simplex methods, we can now solve linear programs with more than one million variables and thousands of constraints. Preprocessing and polyhedral theory have yielded at least an order of magnitude improvement in branch-and-bound algorithms for solving mixed integer programs. Moreover, these algorithmic a...
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作者：SADRIAN, AA; YOON, YS
摘要：Emergence of a new discount pricing schedule called Business Volume Discount becomes a major obstacle for procurement managers in finding the best purchasing strategy. In the context of business volume discount, a supplier offers discounts on total dollar amount of sales volume, not on the quantity or variety of the products purchased from the supplier. This paper describes a Procurement Decision Support System (PDSS) that has been successfully implemented to improve the purchasing activities ...
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作者：KREIMER, J; MEHREZ, A
作者单位：Ben-Gurion University of the Negev; University System of Ohio; Kent State University; Kent State University Kent; Kent State University Salem; University System of Ohio; Ohio University; McMaster University
摘要：We obtain an optimal operation policy for a general n-server (channel, machine) stand-by system involving preventive maintenance and operating in real time. We show that such a policy is achieved by successive total use of each server capacity, and does not depend on the arrival pattern of processed data and task duration. We show also that this policy is optimal for any finite, initial period of time, and not only in the sense of long-run availability. The analysis is performed in two stages:...
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作者：ROTHKOPF, MH
作者单位：Rutgers University System; Rutgers University New Brunswick
摘要：The OR Practice Section of Operations Research is approaching its tenth anniversary. This note ''amines and interprets the nature of the papers that it has attracted and argues that they suggest vigor in the practice of operations research.
