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作者：Chun, So Yeon; Shapiro, Alexander; Uryasev, Stan
作者单位：Georgetown University; University System of Georgia; Georgia Institute of Technology; State University System of Florida; University of Florida
摘要：We discuss linear regression approaches to the estimation of law-invariant conditional risk measures. Two estimation procedures are considered and compared; one is based on residual analysis of the standard least-squares method, and the other is in the spirit of the M-estimation approach used in robust statistics. In particular, value-at-risk and average value-at-risk measures are discussed in detail. Large sample statistical inference of the estimators is derived. Furthermore, finite sample p...
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作者：Akan, Mustafa; Alagoz, Oguzhan; Ata, Baris; Erenay, Fatih Safa; Said, Adnan
作者单位：Carnegie Mellon University; University of Wisconsin System; University of Wisconsin Madison; Northwestern University; University of Waterloo; University of Wisconsin System; University of Wisconsin Madison
摘要：We consider the problem of designing an efficient system for allocating donated livers to patients waiting for transplantation. The trade-off between medical urgency and efficiency is at the heart of the liver allocation problem. We model the transplant waiting list as a multiclass fluid model of overloaded queues, which captures the disease evolution by allowing the patients to switch between classes, i.e., health levels. We consider the bicriteria objective of minimizing total number of pati...
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作者：Chen, Li; Lee, Hau L.
作者单位：Duke University; Stanford University
摘要：The bullwhip effect, or demand information distortion, has been a subject of both theoretical and empirical studies in the operations management literature. In this paper, we develop a simple set of formulas that describe the traditional bullwhip measure as a combined outcome of several important drivers, such as finite capacity, batch-ordering, and seasonality. Our modeling framework is descriptive in nature as it features certain plausible approximations that are commonly employed in practic...
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作者：Caliskan-Demirag, Ozgun; Chen, Youhua (Frank); Yang, Yi
作者单位：Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; City University of Hong Kong; Zhejiang University
摘要：We consider a stochastic periodic-review inventory control system in which the fixed cost depends on the order quantity. In particular, we investigate the optimal ordering policies under three fixed cost structures. The first structure is motivated by transportation and production contracts and considers two fixed costs: if the order size is within a specified limit C, then the fixed cost is K-1; otherwise, it is K-2, where K-1 <= K-2. The second structure contains multiple fixed costs in whic...
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作者：Huh, Woonghee Tim; Janakiraman, Ganesh
作者单位：University of British Columbia; University of Texas System; University of Texas Dallas
摘要：We study a periodically reviewed multiechelon inventory system in series such that order quantities at every stage have to be multiples of a given stage-specific batch size. The batch sizes are nested in the sense that the batch size for every stage is an integer multiple of the batch size for its downstream stage. The problem is that of determining the policy that minimizes the expected discounted sum of costs over a finite horizon. The result is that an echelon (R, nQ) policy is optimal when...
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作者：Abouee-Mehrizi, Hossein; Balcioglu, Baris; Baron, Opher
作者单位：University of Waterloo; Sabanci University; University of Toronto
摘要：Make-to-stock queues are typically investigated in the M/M/1 settings. For centralized single-item systems with backlogs, the multilevel rationing (MR) policy is established as optimal and the strict priority (SP) policy is a practical compromise, balancing cost and ease of implementation. However, the optimal policy is unknown when service time is general, i.e., for M/G/1 queues. Dynamic programming, the tool commonly used to investigate the MR policy in make-to-stock queues, is less practica...
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作者：Jacobson, Evin Uzun; Argon, Nilay Tanik; Ziya, Serhan
作者单位：Imperial College London; University of North Carolina; University of North Carolina Chapel Hill
摘要：In the aftermath of mass-casualty events, key resources (such as ambulances and operating rooms) can be overwhelmed by the sudden jump in patient demand. To ration these resources, patients are assigned different priority levels, a process that is called triage. According to triage protocols in place, each patient's priority level is determined based on that patient's injuries only. However, recent work from the emergency medicine literature suggests that when determining priorities, resource ...
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作者：Ulu, Canan; Honhon, Dorothee; Alptekinoglu, Aydin
作者单位：University of Texas System; University of Texas Austin; Eindhoven University of Technology; Southern Methodist University
摘要：How should a firm modify its product assortment over time when learning about consumer tastes? In this paper, we study dynamic assortment decisions in a horizontally differentiated product category for which consumers' diverse tastes can be represented as locations on a Hotel ling line. We presume that the firm knows all possible consumer locations, comprising a finite set, but does not know their probability distribution. We model this problem as a discrete-time dynamic program; each period, ...
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作者：Zhang, Hao
作者单位：University of Southern California
摘要：This paper studies an infinite horizon adverse selection model with an underlying Markov information process. It introduces a graphic representation of continuation contracts and continuation payoff frontiers, namely finite policy graph, and provides an algorithm to approximate the optimal policy graph through iterations. The algorithm performs an additional step after each value iteration-replacing dominated points on the previous continuation payoff frontier by points on the new frontier and...
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作者：Rusmevichientong, Paat; Topaloglu, Huseyin
作者单位：University of Southern California; Cornell University
摘要：We study robust formulations of assortment optimization problems under the multinomial logit choice model. The novel aspect of our formulations is that the true parameters of the logit model are assumed to be unknown, and we represent the set of likely parameter values by a compact uncertainty set. The objective is to find an assortment that maximizes the worst-case expected revenue over all parameter values in the uncertainty set. We consider both static and dynamic settings. The static setti...
