normal 0 false false false en-us x-none ar-sa microsoftinternetexplorer4 background: urban living and transition of illnesses, today has led hygienic centers for dedicating services to serious challenge management of an outpatient center is very difficult. worse is that the patient advice and service time is much less than waiting time. many people to avoid long waiting go to private treatment ...

This paper studies a batch arrival single server Bernoulli feedback queue with Poisson arrivals, two stages of heterogeneous service with different (arbitrary) service time distributions subject to random breakdowns and multiple vacations with exponential distributed with Mean vacation time . After first-stage service the server must provide the second stage service. However after the completio...

Queueing networks with finite buffers, multiple servers, arbitrary acyclic, series-parallel topologies, and general service time distributions are considered in this paper. An approach to optimally allocate servers to series, merge, and split topologies and their combinations is demonstrated. The methodology builds upon two-moment approximations to the service time distribution embedded in the ...

We study the waiting-time distributions in cyclic polling models with renewal arrivals, general service and switch-over times, and exhaustive service at each of the queues. The assumption of renewal arrivals prohibits an exact analysis and reduces the available analytic results to heavy-traffic asymptotics, limiting results for large switch-over times and large numbers of queues, and some numer...

In this paper, we present a discrete-time single-server finite-buffer queue in which the server takes single/multiple vacations whenever the system becomes empty. The interarrival times are geometrically distributed and service, vacation times are independently identically distributed random variables and their durations are integral multiples of a slot duration. We obtain the state probabiliti...

This paper analyzes a single-server finite-buffer vacation (single and multiple) queue wherein the input process follows a discrete-time batch Markovian arrival process (D-BMAP). The service and vacation times are generally distributed and their durations are integral multiples of a slot duration. We obtain the state probabilities at service completion, vacation termination, arbitrary, and prea...

We consider an open queueing network consisting of an arbitrary number of queues in series. We assume that the arrival process into the rst queue and the service processes at the individual queues are jointly stationary and ergodic, and that the mean inter-arrival time exceeds the mean service time at each of the queues. Starting from Lindley's recursion for the waiting time, we obtain a simple...

This paper investigate a queueing model where in customers arrive in batches according to compound Poisson process with rate λ and are served one by one in FIFO basis. All incoming customers demand the first ’essential’ service wherein only some of them demand the second ’optional’ service. The service times of both essential and optional services follow arbitrary(general)distribution with diff...

We consider a queueing loss system with heterogeneous skill based servers with arbitrary service distributions. We assume Poisson arrivals, with each arrival having a vector indicating which of the servers are eligible to serve it. An arrival can only be assigned to a server that is both idle and eligible. Assuming exchangeable eligibility vectors and an idle time ordering assignment policy, th...

In this paper, an exact geometric algorithm is presented for solving two-job sequencing and scheduling problems in flexible flow shop and job shop environments while the resources are (un)available in some time periods and processors (un)availability is the same in all work centers. This study seems utterly new and it is applicable to any performance measure based on the completion time. The in...