Showing papers by "Zhe George Zhang published in 2017"
TL;DR: A double-ended queueing system which is motivated by the passenger-taxi problem under a gated policy that makes taxis start to balk when the taxi queue length reaches an upper limit and to join again when the Taxi queue length is reduced to a lower limit is concerned.
24 citations
TL;DR: The minimal total expected long-run net cost per unit time of the system is derived and a computational algorithm for determining the optimal policy is developed and a real-world application from electric power industry is provided.
16 citations
TL;DR: This paper studies a queue with server vacations where customers need complementary services and investigates the equilibriums of such a system in a time-based fee model under competition and monopoly cases, respectively.
Abstract: This paper studies a queue with server vacations where customers need complementary services. The main service provider or the queue server may become absent for a random period of time called a vacation. More specifically, the server adopts a multiple vacation policy which means that the server keeps taking vacations until at least a customer waiting at the vacation completion instant. The secondary service provider offers an instantaneous service (no delay or no queue). The two services are complementary and a customer must receive both services if he or she joins the system. We investigate the equilibriums of such a system in a time-based fee model under competition and monopoly cases, respectively. Furthermore, a fixed or flat fee model is also analysed.
8 citations
TL;DR: A review of methodologies for analyzing stochastic manufacturing and service systems using micro-, meso-, and macro-scopic models is presented to help practitioners select the appropriate level of modeling to enhance their understanding of the dynamic behavior of manufacturing or service systems.
Abstract: This paper presents a review of methodologies for analyzing stochastic manufacturing and service systems. On the basis of the scale and level of details of operations, we can study stochastic systems using micro-, meso-, and macro-scopic models. Such a classification unifies stochastic modeling theory. For each model type, we highlight the advantages and disadvantages and the applicable situations. Micro-scopic models are based on quasi-birth-and-death process because of the phase-type distributed service times and/or Markov arrival processes. Such models are appropriate for modeling the detailed operations of a manufacturing system with relatively small number of servers (production facilities). By contrast, meso-scopic and macro-scopic models are based on the functional central limit theorem (FCLT) and functional strong law of large numbers (FSLLN), respectively, under heavy-traffic regimes. These high-level models are appropriate for modeling large-scale service systems with many servers, such as call centers or large service networks. This review will help practitioners select the appropriate level of modeling to enhance their understanding of the dynamic behavior of manufacturing or service systems. Enhanced understanding will ensure that optimal policies can be designed to improve system performance. Researchers in operation analytics and optimization of manufacturing and logistics also benefit from such a review.
2 citations