共查询到9条相似文献,搜索用时 15 毫秒
1.
This paper studies a single-server priority queueing model in which preemptions are allowed during the early stages of service.
Once enough service effort has been rendered, however, further preemptions are blocked. The threshold where the change occurs
is either a proportion of the service requirement, or time-based. The Laplace–Stieltjes transform and mean of each class sojourn
time are derived for a model which employs this hybrid preemption policy. Both preemptive resume and preemptive repeat service
disciplines are considered. Numerical examples show that it is frequently the case that a good combination of preemptible
and nonpreemptible service performs better than both the standard preemptive and nonpreemptive queues. In a number of these
cases, the thresholds that optimize performance measures such as overall average sojourn time are determined.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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3.
A survey of retrial queues 总被引:18,自引:0,他引:18
Gennadij Falin 《Queueing Systems》1990,7(2):127-167
We present a survey of the main results and methods of the theory of retrial queues, concentrating on Markovian single and multi-channel systems. For the single channel case we consider the main model as well as models with batch arrivals, multiclasses, customer impatience, double connection, control devices, two-way communication and buffer. The stochastic processes arising from these models are considered in the stationary as well as the nonstationary regime. For multi-channel queues we survey numerical investigations of stationary distributions, limit theorems for high and low retrial intensities and heavy and light traffic behaviour. 相似文献
4.
This paper deals with an MX/G/1 queueing system with a vacation period which comprises an idle period and a random setup period. The server is turned
off each time when the system becomes empty. At this point of time the idle period starts. As soon as a customer or a batch
of customers arrive, the setup of the service facility begins which is needed before starting each busy period. In this paper
we study the steady state behaviour of the queue size distributions at stationary (random) point of time and at departure
point of time. One of our findings is that the departure point queue size distribution is the convolution of the distributions
of three independent random variables. Also, we drive analytically explicit expressions for the system state probabilities
and some performance measures of this queueing system. Finally, we derive the probability generating function of the additional
queue size distribution due to the vacation period as the limiting behaviour of the MX/M/1 type queueing system.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
5.
In this paper, we analyse a multi-server queue with bulk arrivals and finite-buffer space. The interarrival and service times
are arbitrarily and exponentially distributed, respectively. The model is discussed with partial and total batch rejections
and the distributions of the numbers of customers in the system at prearrival and arbitrary epochs are obtained. In addition,
blocking probabilities and waiting time analyses of the first, an arbitrary and the last customer of a batch are discussed.
Finally, some numerical results are presented.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
We introduce a simple approach for the analysis of the M/M/c queues with a single class of customers and constant impatience time by finding simple Markov processes (see (2.1) and (2.15) below), and then by applying this approach we analyze the M/M/1 queues with two classes of customers in which class 1 customers have impatience of constant duration, and class 2 customers have no impatience and lower priority than class 1 customers. 相似文献
7.
The M/G/1 queue with impatient customers is studied. The complete formula of the limiting distribution of the virtual waiting time is derived explicitly. The expected busy period of the queue is also obtained by using a martingale argument. 相似文献
8.
In this paper, we analyze a finite buffer queueing model with two servers and two nonpreemptive priority service classes. The arrival streams are independent Poisson processes, and the service times of the two classes are exponentially distributed with different means. One of the two servers is reserved exclusively for one class with high priority and the other server serves the two classes according to a nonpreemptive priority service schedule. For the model, we describe its dynamic behavior by a four-dimensional continuous-time Markov process. Applying recursive approaches we present the explicit representation for the steady-state distribution of this Markov process. Then, we calculate the Laplace–Stieltjes Transform and the steady-state distribution of the actual waiting times of two classes of customers. We also give some numerical comparison results with other queueing models. 相似文献
9.
《随机分析与应用》2013,31(3):739-753
Abstract We consider an M x /G/1 queueing system with a random setup time, where the service of the first unit at the commencement of each busy period is preceded by a random setup time, on completion of which service starts. For this model, the queue size distributions at a random point of time as well as at a departure epoch and some important performance measures are known [see Choudhury, G. An M x /G/1 queueing system with setup period and a vacation period. Queueing Sys. 2000, 36, 23–38]. In this paper, we derive the busy period distribution and the distribution of unfinished work at a random point of time. Further, we obtain the queue size distribution at a departure epoch as a simple alternative approach to Choudhury4. Finally, we present a transform free method to obtain the mean waiting time of this model. 相似文献