A BMAP/G/1 Retrial Queue with a Server Subject to Breakdowns and Repairs

In this paper, we consider a BMAP/G/1 retrial queue with a server subject to breakdowns and repairs, where the life time of the server is exponential and the repair time is general. We use the supplementary variable method, which combines with the matrix-analytic method and the censoring technique, to study the system. We apply the RG-factorization of a level-dependent continuous-time Markov chain of M/G/1 type to provide the stationary performance measures of the system, for example, the stationary availability, failure frequency and queue length. Furthermore, we use the RG-factorization of a level-dependent Markov renewal process of M/G/1 type to express the Laplace transform of the distribution of a first passage time such as the reliability function and the busy period.     

服务中断的M/M/1重试排队模型的稳态解

研究服务中断的M/M/1重试排队模型的稳态解,证明当α+μ>λ时0不足该模型主算子的特征值.由此推出该模型不存在稳态解.     

Reliability Analysis of the Retrial Queue with Server Breakdowns and Repairs

Retrial queues have been widely used to model many problems arising in telephone switching systems, telecommunication networks, computer networks and computer systems, etc. It is of basic importance to study reliability of retrial queues with server breakdowns and repairs because of limited ability of repairs and heavy influence of the breakdowns on the performance measure of the system. However, so far the repairable retrial queues are analyzed only by queueing theory. In this paper we give a detailed analysis for reliability of retrial queues. By using the supplementary variables method, we obtain the explicit expressions of some main reliability indexes such as the availability, failure frequency and reliability function of the server. In addition, some special queues, for instance, the repairable M/G/1 queue and repairable retrial queue can be derived from our results. These results may be generalized to the repairable multi-server retrial models.     

具有Bernoulli休假的M/G/1重试可修的排队系统

本文研究了具有Bernoulli休假、一般重试的服务台可修的M/G/1排队系统,求得系统稳态解存在的充分必要条件.利用补充变量法求得系统的排队指标和可靠性指标.     

带特殊重试时间的M/M/1重试排队模型的一个特征值

证明0是对应于带特殊重试时间的M/M/1重试排队模型主算子的几何重数为1的特征值,0是此主算子的共轭算子的特征值.     

M/M/1 Retrial Queue with Collisions and Transmission Errors

Methodology and Computing in Applied Probability - In this paper, an M/M/1 retrial queue with collisions and transmission errors is considered. The collision may occur when a primary arriving...     

带特殊重试时间的M／M／1重试排队模型的另一个特征值

研究对应于带特殊重试时间的M／M／1重试排队模型主算子在左半复平面的谱,证明-（2λ＋α＋β＋√（α＋β）^2＋4λβ/4是该主算子的几何重数为1的特征值．     

关于两类M/M/1排队系统的渐进稳定性

讨论了两类M/M/1排队系统的关系,通过较简单的方法得到了系统的稳态解是渐进稳定的.     

On the Relative Waiting Times in the GI/M/s and the GI/M/1 Queueing Systems

The expected steady-state waiting time, Wq(s), in a GI/M/s system with interarrival-time distribution H(·) is compared with the mean waiting time, Wq, in an "equivalent" system comprised of s separate GI/M/1 queues each fed by an interarrival-time distribution G(·) with mean arrival rate equal to 1/s times that of H(·). For H(·) assumed to be Exponential, Gamma or Deterministic three possible relationships between H(·) and G(·) are considered: G(·) can be of the "same type" as H(·); G(·) can be derived from H(·) by assigning new arrivals to the individual channels in a cyclic order; and G(·) may be obtained from H(·) by assigning customers probabilistically to the different queues. The limiting behaviour of the ratio R = Wq/Wq(s) is studied for the extreme values (1 and 0) of the common traffic intensity, ρ. Closed form results, which depend on the forms of H(·) and G(·) and on the relationships between them, are derived. It is shown that Wq is greater than Wq(s) by a factor of at least (s + 1)/2 when ρ approaches one, and that R is at least s(s!) when ρ tends to zero. In the latter case, however, R goes to infinity (!) in most cases treated. The results may be used to evaluate the effect on the waiting times when, for certain (non-queueing) reasons, it is needed to partition a group of s servers into several small groups.     

GI/M/1 Queue with Server Vacations

A queueing model with server vacations is studied in which it is assumed that the interarrival time has a general distribution, the service-time distribution is exponential and vacations are independently and indentically distributed with a general distribution. Using the embedded Markov chain technique, the equilibrium probability distributions of system size have been obtained at pre-arrival and at random epochs separately. Finally, the distribution of waiting time of a customer in the queue (excluding service) has been derived.     

带负顾客,反馈,服务台可修的M/G/1重试排队系统

对负顾客的研究可以从不同的角度,不同的方法,不同的机制来进行.本文提出了带负顾客,反馈,服务台可修的M/G/1重试排队系统.其中负顾客的机制是带走正在接受服务的正顾客和使得服务器处于修理状态.在假定重试区域中只有队首的顾客允许重试的情况下,重试时间具有一般分布时,得到了系统稳态的充分必要条件.求得了系统稳态时队长和重试区域中队长分布及一些排队指标和可靠性指标.     

两类负顾客M/GI/1系统的统计平衡条件

负顾客排队模型由于其灵活模拟各种复杂随机现象的广阔的应用前景，当前正越来越受到各类高性能通讯网络研究多方面的广泛关注．由于负顾客的抵消作用这类系统可以容许在顾客到达率大于服务率的情况下，进入平稳状态．本文用马尔可夫更新理论和Foster负偏移准则，研究了两类M／GI／1负顾客排队模型进入平稳状态的充要条件，首次得到了负顾客更新到达情况下，带负顾客抵消队列头部正顾客和队列尾部正顾客两种策略下的M／GI／1（FCFS）系统的统计平衡条件．当负顾客到达取更新过程的特例一泊松过程时，这一结果与Harrison＆Pital（1996）中所得结果完全一致．     

M/G/1重试排队系统的渐近稳定性

用算子半群理论研究了带有重试排队的M/G/1系统.通过解算子方程和预解方程,证明了0是系统算子的本征值,且为虚轴上唯一的谱点.从而得出了当时间趋于无穷时系统时间依赖解收敛于稳态解的结论.     

An M/G/1 Retrial Queueing System with Two-Phase Service and Preemptive Resume

An M/G/1 retrial queueing system with additional phase of service and possible preemptive resume service discipline is considered. For an arbitrarily distributed retrial time distribution, the necessary and sufficient condition for the system stability is obtained, assuming that only the customer at the head of the orbit has priority access to the server. The steady-state distributions of the server state and the number of customers in the orbit are obtained along with other performance measures. The effects of various parameters on the system performance are analysed numerically. A general decomposition law for this retrial queueing system is established.     

服务员强制休假的M/M/1排队模型的另一个特征值

研究服务员强制休假的M/M/1排队模型的主算子在左半复平面中的特征值,证明(λ-μ-b)-√(b+μ)2-3λ2-μb/2是该主算子的几何重数为1的特征值.     

GI／G／1和GI／M／1的队长的瞬时分布

在本中给出了GI/G／1和GI／M／1的队长L(t)的瞬时分布的计算方法。     

N-策略休假排队系统中异质信息顾客策略分析

本文研究N-策略休假M/M/1排队系统中的异质信息顾客策略和社会最优收益。来到系统的顾客分为两类,第一类顾客有系统信息,加入系统前知道服务员的状态和系统中顾客数;第二类顾客没有系统信息,加入系统前既不知道服务员的状态,也不知道系统中顾客数。利用粒子群优化算法,分析了两类顾客的最优策略行为和最优社会收益。结果表明,最优社会收益随着转换门限N的增大而减小,随着v和系统负载p的增大而增大。并且,第一类顾客的比例越大,社会收益越大。     

The Finite Capacity GI/M/1 Queue with Server Vacations

We consider the GI/M/1/K queue where the server takes exponentially distributed vacations when there are no customers left to serve in the queue. We obtain the queue length distribution at arrival epochs and random epochs for the multiple vacation case. We present heuristic algorithms to compute the blocking probability for this system. Several numerical examples are presented to analyze the behaviour of the blocking probability and to test the performance of the heuristics.