Inventory models with lost sales and large lead times are notoriously difficult to manage due to the curse of dimensionality. Recently, Goldberg et al. (2016) and Xin and Goldberg (2016) proved that in the lost-sales inventory model with divisible products, as the lead time grows large, a simple...

In low-density rural areas, implementing traditional public transportation can be challenging due to the first-and-last-mile problem. With the development of transformative technologies, an online ride-sharing platform can be a solution to address the rural mobility problem by offering on-demand...

We consider a partially observable inventory system in which the inventory level can only be observed when it reaches zero, the unmet demand is lost, and replenishment orders must be decided so as to minimize the long-run average cost. This problem has an infinite-dimensional state space and is...

We consider a generic Markov decision process (MDP) with two controls: one control taking effect immediately and the other control whose effect is delayed by a positive lead time. Computing the optimal policy of this MDP is difficult when the lead time is large. Interestingly, as the lead time...