Xiangtong Qi

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We study the problem of a manufacturer who outsources a single product to multiple capacitated suppliers. Given a pool of potential suppliers, a decision has to be made about which supplier(s) to use, and how much and how often to purchase from each selected supplier. We build an EOQ-type model with a finite-time horizon, which differs from the existing(More)
In this research, we introduce a dual-purpose simulation model that integrates two decision support systems used by the US Postal Service to configure and staff their mail processing and distribution centers (P&DCs). The first system is designed to optimize the daily equipment schedules and the second to optimize the size and composition of the permanent(More)
We study the problem of recovering a production plan after a disruption, where the disruption may be caused by incidents such as power failure, market change, machine breakdown, supply shortage, worker no-show, and others. The new recovery plan we seek after has to not only suit the changed environment brought about by the disruption, but also be close to(More)
Multicast is an important application in all-optical WDM networks. The wavelength assignment problem for WDM multicast is to assign a set of wavelengths to the links of a given multicast tree. In an all-optical WDM network without wavelength conversions, wavelength assignment is the key to guarantee the quality of service and to reduce communication costs.(More)