We study the stochastic machine replenishment problem, which is a canonical special case of closed multiclass queuing systems in Markov decision theory. The problem models the scheduling of processor repairs in a multiprocessor system in which one repair can be made at a time and the goal is to maximize system utilization. We analyze the performance of a natural greedy index policy for this pro...

In this research, we propose a weighted class based queuing (WCBQ) mechanism to provide class differentiation and to reduce the load for the IMS (IP Multimedia Subsystem) presence server (PS). The tasks of admission controller for the PS are demonstrated. Analysis and simulation models are developed to quantify the performance of WCBQ scheme. An optimized dropping time frame has been developed ...

Modeling and predicting age differences in driver mental workload and performance may help the invehicle system design to reduce or prevent information overloading on older drivers. However, few computational models exist that account for age differences in mental workload. We propose a new computational modeling approach to model workload and performance—a queuing network approach based on que...

We consider queuing systems as models of distance learning system we analyze how characteristics of business process in the system affect on throughput and on learning outcomes. The processes of executing tasks and tasks validation process are the key processes in the distance learning. A model of the process performed by a student is a queuing system with refusals. A model of the process perfo...

We discuss some known and some new results on the score function (SF) approach for simulation analysis. We show that while simulating a single sample path from the underlying system or from an associated system and applying the Radon-Nikodym measure one can: estimate the performance sensikGries (gradient, Hessian etc.) of the underlying system with respect to some parameter (vector of parameter...

We develop a new approach to queuing analysis for an infinite-length queue with constant service rate fed by any traffic process. Our approach provides important theoretical results, is easy to implement in practice, and is particularly relevant to queues fed with long-range-dependent (LRD) traffic. We use traffic statistics at only a small fixed set of time scales and develop three approximati...

A crucial factor for real-time (interactive) services is the end-to-end delay experienced by the application. The contribution resulting from the queuing delay induced by the network nodes is the most difficult to assess. First, it is a stochastic quantity which should be aggregated over many (possibly different) network nodes. Secondly, the queuing delay in a single node stems from two differe...

In a heterogeneous parallel computer system, the computational power of each of the processors differs from one another. Furthermore, with distributed memory, the capacity of the memory, which is distributed to each of the processors, differs from one another. Using queuing system to describe a distributed memory heterogeneous parallel computer system, each of the heterogeneous processors will ...