This investigation deals with M/M/R/N machine repair problem with R non-reliable service stations which are subjected to unpredictable breakdown. 1here is provision of an additional server to reduce backlog in the case of heavy load of failed machines. 1he permanent service stations repair the failed machines at an identical rate m and switch to faster repair rate when all service stations are ...

This paper reports a study on a single server queue with bulk arrival and bulk service patterns wherein the incoming traffic depends on the state of the server which may be in operating or breakdown state. The repair of the breakdown server is performed in two phases. The operating duration of server, repair duration of both phases of repairing as well as job's inter-arrival times and service t...

This investigation deals with MX/G/1 queueing model with setup, bulk- arrival, loss-delay and balking. The provision of second optional service apart from essential service by an unreliable server is taken into consideration. We assume that the delay customers join the queue when server is busy whereas loss customers depart from the system. After receiving the essential service, the customers m...

In this paper we consider M[X]/G(a, b)/1 queueing system with accessible service, server breakdown without interruption, multiple vacation and closedown time. The service rule is as follows: the server starts service only when a minimum number of customers ′a′ is available in the queue and the maximum service capacity is ′b′ units such that late entries are allowed to join a service batch, with...

I present a summary of recent use of the Open Archives Initiative (OAI) registration and validation services for data-providers. The registration service has seen a steady stream of registrations since its launch in 2002, and there are now over 220 registered repositories. I examine the validation logs to produce a breakdown of reasons why repositories fail validation. This breakdown highlights...

Experimental Study of degradation of oil impregnated paper has attracted enormous attention over the past 20 years worldwide. Outside the controlled conditions of the laboratory, however the real situation is more complex due to loading change, ambient temperature, fluctuation and sudden impulse impact. Therefore, interests in forensic examinations of scrapped old transformers have increased in...

1569-190X/$ see front matter 2009 Elsevier B.V doi:10.1016/j.simpat.2009.09.013 * Corresponding author. Tel.: +353 857254678. E-mail address: [email protected] (J. Byrne). The area of Web-based simulation (the integration of the Web with the field of simulation) (WBS) has grown since the mid-1990s. The Web itself has evolved rapidly, and current Web-related research areas include Web 2.0, servi...

The present investigation deals with the bulk arrival M/G/1 retrial queue with impatient customers and modified vacation policy. The incoming customers join the virtual pool of customers called orbit if they find the server being busy, on vacation or in broken down state otherwise the service of the customer at the head of the batch is started by the server. The service is provided in k</em...

Consider a single server queue in which the service station may breakdown according to a Poisson process with rates γ in busy time and γ’ in idle time respectively. After a breakdown, the service station will be repaired immediately and the repair time is assumed to have an exponential distribution with rate δ. Suppose the arrival time has an exponential distribution with rate λ, and the probab...