在延迟Min (N, D)-策略M/G/1可修排队系统及最优控制策略
潘取玉,唐应辉

Analysis of M/G/1 Repairable Queueing System and Optimal Control Policy with a Replaceable Repair Facility Under Delay Min(N, D)-Policy
Quyu Pan,Yinghui Tang
图 7 每单位时间内所需费用的期望值随$N$$D$的变化情况