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作者：Bergman, David; Cardonha, Carlos H.; Cire, Andre A.; Raghunathan, Arvind U.
作者单位：University of Connecticut; University of Toronto; University Toronto Scarborough; University of Toronto
摘要：A graph is chordal if every cycle with at least four edges contains a chord-that is, an edge connecting two nonconsecutive vertices of the cycle. Several classical applications in sparse linear systems, database management, computer vision, and semidefinite programming can be reduced to finding the minimum number of edges to add to a graph so that it becomes chordal, known as the minimum chordal completion problem (MCCP). We propose a new formulation for the MCCP that does not rely on finding ...
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作者：Levi, Retsef; Perakis, Georgia; Romero, Gonzalo
作者单位：Massachusetts Institute of Technology (MIT); University of Toronto
摘要：We study a subsidies and taxes allocation problem with endogenous market response subject to a budget constraint. The central planner's objective is to maximize the consumption of a good, and she allocates per-unit copayments and taxes to its producers. We show that the optimal policy taxes the more efficient firms and allocates larger copayments to less efficient firms, making it impractical. Therefore, we consider the simple and frequently implemented policy that allocates the same copayment...
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作者：Song, Eunhye; Nelson, Barry L.
作者单位：Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Northwestern University
摘要：When input distributions to a simulation model are estimated from real-world data, they naturally have estimation error causing input uncertainty in the simulation output. If an optimization via simulation (OvS) method is applied that treats the input distributions as correct, then there is a risk of making a suboptimal decision for the real world, which we call input model risk. This paper addresses a discrete OvS (DOvS) problem of selecting the real-world optimal from among a finite number o...
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作者：Ata, Baris; Lee, Deishin; Sonmez, Erkut
作者单位：University of Chicago; Western University (University of Western Ontario); University of Nebraska System; University of Nebraska Lincoln
摘要：Gleaning programs organize volunteer gleaners to harvest a variety of leftover crops that are donated by farmers for the purpose of feeding food-insecure individuals. Thus, the gleaning process simultaneously reduces food waste and food insecurity. However, the operationalization of this process is challenging because gleaning relies on two uncertain sources of input: the food and labor supplies. The purpose of this paper is to help gleaning organizations increase the (value-weighted) volume o...
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作者：Bray, Robert L.; Yao, Yuliang; Duan, Yongrui; Huo, Jiazhen
作者单位：Northwestern University; Lehigh University; Tongji University
摘要：We model a single-supplier, 73-store supply chain as a dynamic discrete choice problem. We estimate the model with transaction-level data, spanning 3,251 products and 1,370 days. We find two interrelated phenomena: the bullwhip effect and ration gaming. To establish the bullwhip effect, we show that shipments from suppliers are more variable than sales to customers. To establish ration gaming, we show that upstream scarcity triggers inventory runs, with stores simultaneously scrambling to amas...
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作者：Balseiro, Santiago R.; Brown, David B.
作者单位：Columbia University; Duke University
摘要：In the analysis of complex stochastic dynamic programs, we often seek strong theoretical guarantees on the suboptimality of heuristic policies. One technique for obtaining performance bounds is perfect information analysis: this approach provides bounds on the performance of an optimal policy by considering a decision maker who has access to the outcomes of all future uncertainties before making decisions, that is, fully relaxed nonanticipativity constraints. A limitation of this approach is t...
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作者：Cruise, James; Flatley, Lisa; Gibbens, Richard; Zachary, Stan
作者单位：Heriot Watt University; University of Warwick; University of Cambridge
摘要：We study the control of large-scale energy storage operating in a market. Reoptimization of deterministic models is a common pragmatic approach when prices are stochastic. We apply Lagrangian theory to develop such a model and to establish decision and forecast horizons when storage trading affects these prices, an important aspect of some energy markets. The determination of these horizons also provides a simple and efficient algorithm for the determination of the optimal control. The forecas...
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作者：Eisenhandler, Ohad; Tzur, Michal
作者单位：Tel Aviv University
摘要：Food rescue-the collection of perishable products from food suppliers who are willing to make donations, and their distribution to welfare agencies that serve individuals in need-has become increasingly widespread in recent years. This phenomenon is a result of economic crises, but it is also encouraged by the tax and good image it provides to donor companies. The problem we study in this paper focuses on the logistic challenges of a food bank that on a daily basis uses vehicles of limited cap...
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作者：Bensoussan, Alain; Chevalier-Roignant, Benoit
作者单位：University of Texas System; University of Texas Dallas; City University of Hong Kong; University of London; King's College London
摘要：This paper considers a firm's capacity expansion decisions under uncertainty. The firm has leeway in timing investments and in choosing how much capacity to install at each investment time. We model this problem as the sequential exercising of compound capacity expansion options with embedded optimal capacity choices. We employ the impulse control methodology and obtain a quasi-variational inequality that involves two state variables: an exogenous, stochastic price process and a controlled cap...
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作者：Anderson, Edward J.; Philpott, Andrew B.
作者单位：University of Sydney; University of Auckland
摘要：We consider the use of forward contracts to reduce risk for firms operating in a spot market. Firms have private information on the distribution of prices in the spot market. We discuss different ways in which firms may agree on a bilateral forward contract: either through direct negotiation or through a broker. We introduce a form of supply-function equilibrium in which two firms each offer a supply function, and the clearing price and quantity for the forward contracts are determined from th...
