Yusen Xia

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This paper proposes a new model for portfolio selection in which the expected returns of securities are considered as variables rather than as the arithmetic means of securities. A genetic algorithm is designed to solve the optimization problem which is di$cult to solve with the existing traditional algorithms due to its nonconcavity and special structure.(More)
In this paper, we investigate how opportunities to invest in demand enhancing services for a product line affect the interactions between a manufacturer and her dealer. Many demand enhancing services, e.g. after sales support, warranty repair etc. can be provided either by the manufacturer or they can be delegated to the dealer. We first show that when a(More)
We study the optimal production-inventory-outsourcing policy for a firm with Markovian in-house production capacity that faces independent stochastic demand and has the option to outsource. We find very simple optimal policy forms under fairly reasonable assumptions. In addition, when the capacity Markov process is stochastically monotone, the policy(More)
We consider a stochastic inventory control problem with Markovian capacity and the option of order rejection. We show its optimal policy to be the combination of a capacity-dependent modified base-stock production policy and a capacity-dependent critical-point order acceptance policy. When capacity is stochastically monotone, we show that the policy(More)