In most queueing systems the server may be subjected to lengthy and unpredictable breakdowns while serving a customer. For instance, in manufacturing systems the machine may breakdown due to malfunction or job related problems; in computer systems, the machine may be subject to scheduled backups and predicted failures. In these systems, server breakdown results in a period of server unavailabil...

Abstract This paper studies a batch arrival queueing system in which the server may face occasional random breakdowns. The repair process does not start immediately after a breakdown and there is a delay time waiting for repairs to start. Further, after every service completion the server has the option to leave for a vacation with probability p or continue serving with probability1 − p. The ma...

A severe outbreak of cholera has been reported in Zimbabwe since mid 2008, with so far over 92,000 cases and over 4,000 deaths. This outbreak has differed from previous outbreaks in being mainly urban and with a high case-fatality rate. Breakdown in the supply of clean water has been the main underlying cause but breakdown in health service delivery in Zimbabwe has also contributed to the magni...

A gravitational scenario is proposed where the euclidean action is invariant under the isotropic and homogeneous version of the euclidean U(1) group of local transformations of the scale factor and scalar matter field, interpreting the trace of the second fundamental form as the gauge field. The model allows spontaneous breakdown of some involved symmetries, including possibly diffeomorphism in...

This study explains the breakdown mechanism in different triggered spark gap switches. Two different trigger electrode configurations are tested for the switch predischarge operation in a nitrogen laser circuit. The behavior of the breakdown voltage, when a trigger pulse is applied to the trigger electrode, is investigated, and the results are reported. Based on the experimental measurements ne...

This paper deals with the transient analysis of batch arrival retrial queueing system with general retrial times, priority service, balking, second optional service, Bernoulli vacation, extended vacation, breakdown, delayed repair and stand by server. Here we assume that customers arrive in batches according to compound Poisson processes, where the blocked customers either with probability p jo...

The purpose of this research paper was to propose a method which can be utilized to determine the different types of performance measures on the basis of the crisp values for the fuzzy queuing model which has an unreliable server and where the rate of arrival, the rate of service, the rate of breakdown and the rate of repair are all expressed as the fuzzy numbers. In this case the inter arrival...

In this study, an improved trapping/detrapping model was used to simulate the charge dynamics in cross-linked polyethylene peelings from different-year aged cables. Injection barrier of trapping parameters was estimated by the model fitted to experimental data for each type of sample. Moreover, dc breakdown tests were operated on those samples. It has been found that the dc breakdown strength o...

In this paper, we considered a batch arrival feedback retrial queue with two phase of service under Bernoulli vacation schedule and orbit search. At the arrival epoch of a batch, if the server is busy, under repair or on vacation then the whole batch joins the orbit. Where as if the server is free, then one of the arriving customers starts his service immediately and the rest join the orbit. At...

Multipactor breakdown analysis is presented in cylindrical dielectric resonator waveguide filter under its dual-mode behavior. The method of effective electron algorithm with combination of Monte-Carlo method is used to perform the simulation and predict multipactor breakdown thresholds. The breakdown thresholds of the proposed structure are presented for different values of frequency-gap produ...