Considering the competition in today’s business environment, tactical planning of a supply chain becomes more complex than before. In many multi-product inventory systems, substitution flexibility can improve profits. This paper aims to prepare a comprehensive substitution inventory model, where an inventory system with two substitute products with ignorable lead time has been considered, and e...

We consider a queuing network with M exponential service stations and with N customers. We study the behavior of a subsystem u, which has a single node as input and a single node as output, when the subsystem parameters are varied. An “equivalent” network is constructed in which all queues except those in subsystem u are replaced by a single composite queue. We show that for certain classes of ...

A fuzzy queuing coherent hierarchical location-allocation model is developed for congested systems. The parameters of the model are approximately evaluated and stated as fuzzy-numbers. The coverage of demand nodes is also considered in an approximate manner and is stated by the degree of membership. Using the queuing theory and fuzzy conditions, a coherent hierarchical model is developed for th...

Based on queuing theory we develop an analytical approximation for low and high priority packet delays in a Spatial Reuse Protocol (SRP) ring.

Accurate modeling of queueing dynamics is important in the design and analysis of Internet congestion control. However, as demonstrated in this paper, existing window-based queueing models [26,30] are often not capable of precisely capturing the transient behavior (i.e., self-clocking and burstiness) of TCP-like protocols and their resulting analysis may be inaccurate in practice. As one exampl...

This paper analyzes the performance of single-source and single-relay SR-CARQ protocol in TDMA wireless communication system. We establish its M/G/1 queuing model with vacations, and provide the expressions of its system time delay and saturation throughput. Then the analysis of theory and simulation results under the slow Raleigh fading channel show that under what conditions the SR-CARQ proto...

In our work we use queuing theory both for security (i.e. anonymity) and performance analysis. A well-known anonymity technique, the MIX method, which is the basis of most of today’s deployments, is the object of our investigation. We show shortcomings and problems in the MIX method and suggest possible workarounds. Our investigation reveals the level of security of MIX based systems and their ...