带有破坏性负顾客的Geo/Geo/1/MWV可修排队系统均衡策略研究

本文研究带有破坏性负顾客的离散时间Geo/Geo/1/MWV可修排队系统的顾客策略行为.当破坏性负顾客到达系统时,会移除正在接受服务的正顾客,同时造成服务台故障.服务台一旦发生损坏,会立刻接受维修,修理时间服从几何分布.服务台在工作休假期间会以较低的服务速率对顾客进行服务.我们求得系统的稳态分布,进一步给出服务台不同状态下的均衡进入率以及系统单位时间的社会收益表达式.最后对均衡进入率和均衡社会收益进行了数值分析.     

带启动期的Geo/Geo/1/SWV排队系统

考虑带启动期的Geo／Geo／1单重工作休假排队系统，简记为Geo／Geo／1／SWV。服务台在休假期间，不是立即停止服务，而是以较低的服务率为顾客提供服务。应用拟生灭链以及矩阵几何解的方法，本文给出了稳态下顾客数的概率分布、平均队长以及顾客的平均逗留时间，最后通过数值例子说明我们的模型可以较好的模拟一些实际问题。     

有Bernoulli休假和可选服务的Geo/G/1重试排队

讨论了有Bernoulli休假策略和可选服务的离散时间Geo/G/1重试排队系统.假定一旦顾客发现服务台忙或在休假就进入重试区域,重试时间服从几何分布.顾客在进行第一阶段服务结束后可以离开系统或进一步要求可选服务.服务台在每次服务完毕后,可以进行休假,或者等待服务下一个顾客.还研究了在此模型下的马尔可夫链,并计算了在稳态条件下的系统的各种性能指标以及给出一些特例和系统的随机分解.     

具有不同到达率和负顾客的工作休假Geo/Geo/1重试排队

考虑一个具有不同到达率和负顾客的工作休假Geo/Geo/1重试排队,其中正顾客在正常忙期中和工作休假期中的到达率是不同的.假设重试轨道的顾客以一定的重试率进行重试服务,负顾客到达抵消正在接受服务的正顾客.利用拟生灭过程和母函数方法得到了服务台的状态与重试轨道队长的联合分布的概率母函数,从而求得系统在稳态条件下的队长分布等一系列排队指标,进一步讨论了一些特殊情形.最后通过数值实例讨论系统参数对系统主要性能指标的影响,并说明了稳态队长分布在系统容量的优化设计中的重要价值.     

Geo/Geo/1/N型离散时间单重工作休假排队

本文研究了Geo／Geo／1／N型离散时间单重工作休假排队。服务台在假期以较低的速率服务顾客而非停止工作。使用拟生灭链，我们得到稳态下系统中顾客数的分布、顾客的等待时间以及消失概率。更进一步，我们通过数值例子分析了参数对顾客平均等待时间和消失概率的影响来说明我们的模型能够有效的代表一些实际问题。     

带负顾客和N-策略的Geo^{lambda_1, lambda_2/Geo/1(MWV)排队系统分析及最优控制策略N*

分析了一个带有负顾客、N-策略控制的Geo/Geo/1多重工作休假排队系统, 其中正顾客在工作休假及正规忙期以不同的到达率进入系统. 利用拟生灭过程和矩阵几何解方法, 给出了该模型的稳态队长分布及平均队长, 以及系统分别处于假期和忙期的概率. 同时, 对该系统的忙期进行了分析, 并讨论了稳态队长分布在系统容量的优化设计中的应用. 最后, 在给定的费用结构下, 用数值计算例子确定了使系统长期单位时间内期望费用最小的最优控制策 N*.     

带负顾客和N-策略的Geo~(λ_1,λ_2)/Geo/1(MWV)排队系统分析及最优控制策略N~*

分析了一个带有负顾客、N-策略控制的Geo/Geo/1多重工作休假排队系统,其中正顾客在工作休假及正规忙期以不同的到达率进入系统.利用拟生灭过程和矩阵几何解方法,给出了该模型的稳态队长分布及平均队长,以及系统分别处于假期和忙期的概率.同时,对该系统的忙期进行了分析,并讨论了稳态队长分布在系统容量的优化设计中的应用.最后,在给定的费用结构下,用数值计算例子确定了使系统长期单位时间内期望费用最小的最优控制策略N~*.     

具有风险敏感性顾客的离散时间排队系统策略研究

结合博弈论研究排队系统中顾客的策略行为成为当前排队论研究的一个热点.本文研究了离散时间排队系统中风险敏感性顾客的策略行为.不同于经典排队经济学的是,本文的效用函数是期望-方差二次效用函数.根据纳什均衡和马氏过程理论,该文分别研究了在完全可视和完全不可视两种情况下Geo/Geo/1排队系统中风险敏感性顾客的博弈行为.得到了风险敏感性顾客的个体最优策略、社会最优策略和服务商利润最优策略.研究发现,风险敏感系数越小,顾客越喜欢冒险,加入系统的意愿越强.数值实验探索了风险敏感系数对顾客策略行为的影响.     

基于多级适应性休假和$\theta$-进入规则的Geo/G/1排队系统的队长分布[英文]

本文考虑带有多级适应性休假的Geo/G/1离散时间排队系统, 其中在服务员休假期间到达的顾客以概率 $\tha (0 < \tha\leqslant1)$ 进入系统. 运用更新过程理论和全概率分解技术, 从任意初始状态出发, 获得时刻 $n^+$ 处队长瞬态分布的 $z$-变换的递推表达式, 并在瞬时性质分析的基础上, 分别得到时刻 $n^+, n, n^-$ 处队长稳态分布的递推公式, 所得结果进一步表明稳态队长不再具有随机分解结构. 最后通过数值实例, 讨论队长稳态分布对系统参数的敏感性, 并阐述了队长稳态分布的递推公式在系统容量优化设计中的重要应用价值.     

基于多级适应性休假和θ-进入规则的Geo/G/1排队系统的队长分布（英文）

本文考虑带有多级适应性休假的Geo/G/1离散时间排队系统,其中在服务员休假期间到达的顾客以概率θ(0 θ1)进入系统.运用更新过程理论和全概率分解技术,从任意初始状态出发,获得时刻n+处队长瞬态分布的z-变换的递推表达式,并在瞬时性质分析的基础上,分别得到时刻n~+, n, n~-处队长稳态分布的递推公式,所得结果进一步表明稳态队长不再具有随机分解结构.最后通过数值实例,讨论队长稳态分布对系统参数的敏感性,并阐述了队长稳态分布的递推公式在系统容量优化设计中的重要应用价值.     

带启动时间的Geom/Geom/1多重工作休假排队

本文中研究了一个带有启动时间的Geom/Geom/1多重工作休假排队模型。服务台在休假期间,不停止服务,而是以较低的服务率为顾客提供服务。运用拟生灭过程和矩阵几何解的方法,给出了该模型的稳态队长分布,并求出了平均队长以及顾客的平均逗留时间。     

Geo/Geo/1 retrial queue with working vacations and vacation interruption

Consider a Geo/Geo/1 retrial queue with working vacations and vacation interruption, and assume requests in the orbit try to get service from the server with a constant retrial rate. During the working vacation period, customers can be served at a lower rate. If there are customers in the system after a service completion instant, the vacation will be interrupted and the server comes back to the normal working level. We use a quasi birth and death process to describe the considered system and derive a condition for the stability of the model. Using the matrix-analytic method, we obtain the stationary probability distribution and some performance measures. Furthermore, we prove the conditional stochastic decomposition for the queue length in the orbit. Finally, some numerical examples are presented.     

Analysis of the GI/Geo/1 Queue with Disasters

The occurrence of disasters to a queueing system causes all customers to be removed if any are present. Although there has been much research on continuous-time queues with disasters, the discrete-time Geo/Geo/1 queue with disasters has appeared in the literature only recently. We extend this Geo/Geo/1 queue to the GI/Geo/1 queue. We present the probability generating function of the stationary queue length and sojourn time for the GI/Geo/1 queue. In addition, we convert our results into the Geo/Geo/1 queue and the GI/M/1 queue.     

Geo/Geo/1 retrial queue with non-persistent customers and working vacations

In this paper, we consider a Geo/Geo/1 retrial queue with non-persistent customers and working vacations. The server works at a lower service rate in a working vacation period. Assume that the customers waiting in the orbit request for service with a constant retrial rate, if the arriving retrial customer finds the server busy, the customer will go back to the orbit with probability q (0≤q≤1), or depart from the system immediately with probability $\bar{q}=1-q$ . Based on the necessary and sufficient condition for the system to be stable, we develop the recursive formulae for the stationary distribution by using matrix-geometric solution method. Furthermore, some performance measures of the system are calculated and an average cost function is also given. We finally illustrate the effect of the parameters on the performance measures by some numerical examples.     

A GI/Geo/1 queue with negative and positive customers

The arrival of a negative customer to a queueing system causes one positive customer to be removed if any is present. Continuous-time queues with negative and positive customers have been thoroughly investigated over the last two decades. On the other hand, a discrete-time Geo/Geo/1 queue with negative and positive customers appeared only recently in the literature. We extend this Geo/Geo/1 queue to a corresponding GI/Geo/1 queue. We present both the stationary queue length distribution and the sojourn time distribution.     

Discrete-time GI/Geo/1 queue with multiple working vacations

Consider the discrete time GI/Geo/1 queue with working vacations under EAS and LAS schemes. The server takes the original work at the lower rate rather than completely stopping during the vacation period. Using the matrix-geometric solution method, we obtain the steady-state distribution of the number of customers in the system and present the stochastic decomposition property of the queue length. Furthermore, we find and verify the closed property of conditional probability for negative binomial distributions. Using such property, we obtain the specific expression for the steady-state distribution of the waiting time and explain its two conditional stochastic decomposition structures. Finally, two special models are presented.      

The Discrete-Time GI/Geo/1 Queue with Multiple Vacations

We study a discrete-time GI/Geo/1 queue with server vacations. In this queueing system, the server takes vacations when the system does not have any waiting customers at a service completion instant or a vacation completion instant. This type of discrete-time queueing model has potential applications in computer or telecommunication network systems. Using matrix-geometric method, we obtain the explicit expressions for the stationary distributions of queue length and waiting time and demonstrate the conditional stochastic decomposition property of the queue length and waiting time in this system.     

Numerical Computation and Tail Asymptotic for Stationary Indices of a Discrete-Time Vacation Queue

In this paper we study a Geo/Geo/1 queue with T-IPH vacations, where T-IPH denotes the discrete-time phase type distribution defined on a birth and death process with countably many states. Both the multiple and single vacation strategies are considered. For each case, based on the system of stationary equations and using complex analysis method, we firstly give the probability generating functions (PGFs) of stationary distributions for queue length and sojourn time. Moreover, by analysis the PGFs, recursive and asymptotic formulas for additional queue length and additional delay are also given. Finally, we further give some numerical examples to show the effectiveness of the method.