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作者：Klausen, Jytte; Marks, Christopher E.; Zaman, Tauhid
作者单位：Brandeis University; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT)
摘要：Online extremists' use of social media poses a new form of threat to the general public. These extremists range from cyberbullies to terrorist organizations. Social media providers often suspend the extremists' accounts in response to user complaints. However, extremist users can simply create new accounts and continue their activities. In this work we present a new set of operational capabilities to address the threat posed by online extremists in social networks. We use thousands of Twitter ...
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作者：Kress, Moshe; Lin, Kyle Y.; MacKay, Niall J.
作者单位：United States Department of Defense; United States Navy; Naval Postgraduate School; University of York - UK
摘要：We extend classical force-on-force combat models to study the attrition dynamics of three-way and multilateral war. We introduce a new multilateral combat model-the multiduel-which generalizes the Lanchester models, and we solve it under an objective function that values one's own surviving force minus that of one's enemies. The outcome is stark: either one side is strong enough to destroy all the others combined, or all sides are locked in a stalemate, which results in collective mutual annih...
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作者：Nadar, Emre; Akcay, Alp; Akan, Mustafa; Scheller-Wolf, Alan
作者单位：Ihsan Dogramaci Bilkent University; Eindhoven University of Technology; Carnegie Mellon University
摘要：We provide a new method for solving a very general model of an assemble-to-order system: multiple products, multiple components that may be demanded in different quantities by different products, batch production, random lead times, and lost sales, modeled as a Markov decision process under the discounted cost criterion. A control policy specifies when a batch of components should be produced and whether an arriving demand for each product should be satisfied. As optimal solutions for our mode...
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作者：Wu, Shining; Zhang, Jiheng; Zhang, Rachel Q.
作者单位：Hong Kong Polytechnic University; Hong Kong University of Science & Technology
摘要：We consider a band of the electromagnetic spectrum with a finite number of identical channels shared by both licensed and unlicensed users. Such a network differs from most many-server, two-class queues in service systems, including call centers, because of the restrictions imposed on the unlicensed users to limit interference to the licensed users. We first approximate the key performance indicators-namely the throughput rate of the system and the delay probability of the licensed users under...
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作者：Bimpikis, Kostas; Fearing, Douglas; Tahbaz-Salehi, Alireza
作者单位：Stanford University; Northwestern University
摘要：This paper studies sourcing decisions of firms in a multitier supply cham when procurement is subject to disruption risk. We argue that features of the production process that are commonly encountered in practice (including differential production technologies and financial constraints) may result in the formation of inefficient supply chains, owing to the misalignment of the sourcing incentives of firms at different tiers. We provide a characterization of the conditions under which upstream s...
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作者：Keskin, N. Bora; Zeevi, Assaf
作者单位：Duke University; Columbia University
摘要：We consider a dynamic learning problem where a decision maker sequentially selects a control and observes a response variable that depends on chosen control and an unknown sensitivity parameter. After every observation, the decision maker updates his or her estimate of the unknown parameter and uses a certainty-equivalence decision rule to determine subsequent controls based on this estimate. We show that under this certainty-equivalence learning policy the parameter estimates converge with po...
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作者：Sen, Alper; Atamturk, Alper; Kaminsky, Philip
作者单位：Ihsan Dogramaci Bilkent University; University of California System; University of California Berkeley
摘要：We consider the constrained assortment optimization problem under the mixed multinomial logit model. Even moderately sized instances of this problem are challenging to solve directly using standard mixed-integer linear optimization formulations. This has motivated recent research exploring customized optimization strategies and approximation techniques. In contrast, we develop a novel conic quadratic mixed-integer formulation. This new formulation, together with McCormick inequalities exploiti...
