In this paper, we consider retrial queueing systems with batch arrivals in which the server is subject to controllable interruptions (called vacations) and random interruptions (breakdowns). No specific assumption is taken regarding probability distributions of parametric random variables. The purpose of this work is to show effect of above mentioned parameters (in particular retrial and breakd...

We study the convergence of finite-capacity open queueing systems to their infinite-capacity counterparts as the capacity increases. Convergence of the transient behavior is easily established in great generality provided that the finite-capacity system can be identified with the infinitecapacity system up to the first time that the capacity is exceeded. Convergence of steady-state distribution...

Previous statistical tests showed that call center arrival data were consistent with a non-homogeneous Poisson process (NHPP) within each day, but exhibit over-dispersion over multiple days. These tests are applied to arrival data from an endocrinology clinic, where arrivals are by appointment. The clinic data are also consistent with an NHPP within each day, but exhibit under-dispersion over m...

We review some recent work in fast, efficient and accurate methods to compute viscosity solutions and non-viscosity solutions to static HamiltonJacobi equations which arise in optimal control, anisotropic front propagation, and multiple arrivals in wave propagation. For viscosity solutions, the class of algorithms are known as “Ordered Upwind Methods”, and rely on a systematic ordering inherent...

We consider the problem of routing Poisson arrivals toN parallel servers under the condition that the system is heavily loaded. We show that a scheme which limits arrivals to one or two choices and takes into account locality considerations has a diffusion scaled queue length process that is the same as if all of the servers were pooled with a single queue (in other words, no routing decision n...

In this paper we revisit the results of Loynes (1962) on stability of queues for ergodic arrivals and services, and show examples when the arrivals are bounded and ergodic, the service rate is constant, and under stability the limit distribution has larger than exponential tail. Dept. of Computer Science and Information Theory, Technical University of Budapest, 1521 Stoczek u. 2, Budapest, Hung...

Modern telecommunication networks are designed to support converged traffic including voice, data and video. [1] One major feature of these networks is that the input traffic is usually highly bursty.[2] Also, because these networks operate in a packet switching mode, there is usually a strong correlation between packet arrivals. Thus, for these networks the traditional Poisson traffic model ca...

This little book should prove itself invaluable to the great majority of the new yearly arrivals in India. Fully 90 per cent, of new arrivals become possessed of a horse soon after getting to their stations, and a mastering of the details of this little volume will give them a good deal of confidence in selecting a horse that is sound. An examination for soundness includes testing the sight, la...

In this paper, we address the scheduling problem with rejection and non-identical job arrivals, in which we may choose not to process certain jobs and each rejected job incurs a penalty. Our goal is to minimize the sum of the total penalties of the rejected jobs and the maximum completion time of the processed ones. For the off-line variant, we prove its NP-hardness and present a PTAS, and for ...

The steady state distribution of quasi-birth-death pro esses an be eÆ iently obtained by matrix-geometri (MG) methods. Sin e a number of tele ommuni ation problems are modelled by pro esses with bat h arrivals, the extension of MG methods for these pro esses has pra ti al importan e. This paper presents an extension of MG methods whi h is e e tive for the analysis of quasi-birth-death pro esses...