scholarly journals NOTE ON APPROXIMATIONS FOR THE MULTISERVER QUEUE WITH FINITE BUFFER AND DETERMINISTIC SERVICES

2008 ◽  
Vol 22 (4) ◽  
pp. 653-658 ◽  
Author(s):  
Henk Tijms
Keyword(s):  
Performance Measures ◽  
Service Time ◽  
Finite Buffer ◽  
Two Phase ◽  
Sojourn Times ◽  
Deterministic Service ◽  
Service Times ◽  
Phase Process

This article shows that very accurate accurate approximations to performance measures in the multiserver M/D/c/c+N queue with finite buffer and deterministic service times can be obtained by replacing the deterministic service time by a two-phase process with exponential sojourn times and branching probabilities outside the interval [0, 1].

scholarly journals NEGATIVE PROBABILITIES AT WORK IN THE M/D/1 QUEUE

2006 ◽  
Vol 21 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Henk Tijms ◽  
Koen Staats
Keyword(s):  
Waiting Time ◽  
Service Time ◽  
The State ◽  
Finite Capacity ◽  
Two Phase ◽  
Deterministic Service ◽  
Phase Process ◽  
Explicit Expressions

This article derives amazingly accurate approximations to the state probabilities and waiting-time probabilities in the M/D/1 queue using a two-phase process with negative probabilities to approximate the deterministic service time. The approximations are in the form of explicit expressions involving geometric and exponential terms. The approximations extend to the finite-capacity M/D/1/N + 1 queue.

scholarly journals On the independence of sojourn times in tandem queues

1989 ◽  
Vol 21 (2) ◽  
pp. 488-489 ◽  
Author(s):  
Thomas M. Chen
Keyword(s):  
Tandem Queues ◽  
Sojourn Times ◽  
Deterministic Service ◽  
Service Times

Reich (1957) proved that the sojourn times in two tandem queues are independent when the first queue is M/M /1 and the second has exponential service times. When service times in the first queue are not exponential, it has been generally expected that the sojourn times are not independent. A proof for the case of deterministic service times in the first queue is offered here.

Analysis of Finite Buffer Markovian Queue with Balking, Reneging and Working Vacations

2013 ◽  
Vol 4 (1) ◽  
pp. 1-24 ◽  
Author(s):  
P. Vijaya Laxmi ◽  
V. Goswami ◽  
K. Jyothsna
Keyword(s):  
Performance Measures ◽  
Finite Buffer ◽  
State Behavior ◽  
Arrival Times ◽  
Service Period ◽  
Markovian Queue ◽  
Special Cases ◽  
Working Vacations ◽  
Service Times ◽  
Vacation Period

This article presents the analysis of a finite buffer M/M/1 queue with multiple and single working vacations. The arriving customers balk (that is do not join the queue) with a probability and renege (that is leave the queue after joining) according to exponential distribution. The inter-arrival times, service times during a regular service period, service times during a vacation period and vacation times are independent and exponentially distributed random variables. Steady-state behavior of the model is considered and various performance measures, some special cases of the model and cost analysis are discussed.

scholarly journals On the independence of sojourn times in tandem queues

1989 ◽  
Vol 21 (02) ◽  
pp. 488-489
Author(s):  
Thomas M. Chen
Keyword(s):  
Tandem Queues ◽  
Sojourn Times ◽  
Deterministic Service ◽  
Service Times

Reich (1957) proved that the sojourn times in two tandem queues are independent when the first queue is M/M /1 and the second has exponential service times. When service times in the first queue are not exponential, it has been generally expected that the sojourn times are not independent. A proof for the case of deterministic service times in the first queue is offered here.

A Note on Bounds and Error Bounds for Nonexponential Batch Arrival Systems

1997 ◽  
Vol 11 (2) ◽  
pp. 189-201 ◽  
Author(s):  
Masakiyo Miyazawa ◽  
Nico M. van Dijk
Keyword(s):  
Performance Measures ◽  
Error Bounds ◽  
Sample Path ◽  
Practical Interest ◽  
Batch Arrival ◽  
Finite Buffer ◽  
Infinite Space ◽  
Proof Techniques ◽  
Service Times ◽  
Markov Reward

This note studies the comparison of finite-buffer and nonexponential batch arrival systems of the form Gx/M/c/c + N with the corresponding systems, with N replaced by N', where N' can be smaller, larger, or infinite. If N' = ∞ the service times can be arbitrarily distributed. Both comparison and error bounds are obtained for performance measures such as the throughput, the idle probability, and the active server distribution. The results are of practical interest to establish computational reductions, either by infinite-space approximation or by reduced finite truncations. Two different proof techniques will be employed: the sample path approach and the Markov reward approach. The comparison of these two techniques is of interest in itself, showing the advantage and disadvantage of each.

The dependence of sojourn times on service times in tandem queues

1984 ◽  
Vol 21 (3) ◽  
pp. 661-667 ◽  
Author(s):  
Xi-Ren Cao
Keyword(s):  
Sojourn Time ◽  
Past History ◽  
Interarrival Time ◽  
Conditional Probabilities ◽  
Tandem Queues ◽  
Sojourn Times ◽  
Distributed Service ◽  
Service Times

In this paper we study a series of servers with exponentially distributed service times. We find that the sojourn time of a customer at any server depends on the customer's past history only through the customer's interarrival time to that server. A method of calculating the conditional probabilities of sojourn times is developed.

Generic application of an aqueous two-phase process for protein recovery from animal blood

2000 ◽  
Vol 35 (7) ◽  
pp. 665-673 ◽  
Author(s):  
Marco Rito-Palomares ◽  
Christopher Dale ◽  
Andrew Lyddiatt
Keyword(s):  
Protein Recovery ◽  
Two Phase ◽  
Animal Blood ◽  
Phase Process

scholarly journals Tails in generalized Jackson networks with subexponential service-time distributions

2005 ◽  
Vol 42 (2) ◽  
pp. 513-530 ◽  
Author(s):  
François Baccelli ◽  
Serguei Foss ◽  
Marc Lelarge
Keyword(s):  
Closed Form ◽  
Service Time ◽  
Large Deviation ◽  
Exact Asymptotics ◽  
Fluid Limits ◽  
Jackson Networks ◽  
Single Station ◽  
Service Times

We give the exact asymptotics of the tail of the stationary maximal dater in generalized Jackson networks with subexponential service times. This maximal dater, which is an analogue of the workload in an isolated queue, gives the time taken to clear all customers present at some time t when stopping all arrivals that take place later than t. We use the property that a large deviation of the maximal dater is caused by a single large service time at a single station at some time in the distant past of t, in conjunction with fluid limits of generalized Jackson networks, to derive the relevant asymptotics in closed form.

scholarly journals Queues with two units connected in series with a multiserver bulk service with accessible and non accessible batch in unit II

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
G. Ayyappan ◽  
S. Velmurugan
Keyword(s):  
Service Time ◽  
Subject Classification ◽  
Geometric Method ◽  
Finite Buffer ◽  
Queueing Model ◽  
Service Station ◽  
Matrix Geometric Method ◽  
In Series ◽  
Bulk Service ◽  
Number Of Customers

This paper analyses a queueing model consisting of two units I and II connected in series, separated by a finite buffer of size N. Unit I has only one exponential server capable of serving customers one at a time. Unit II consists of c parallel exponential servers and they serve customers in groups according to the bulk service rule. This rule admits each batch served to have not less than ‘a’ and not more than ‘b’ customers such that the arriving customers can enter service station without affecting the service time if the size of the batch being served is less than ‘d’ ( a ≤ d ≤ b ). The steady stateprobability vector of the number of customers waiting and receiving service in unit I and waiting in the buffer is obtained using the modified matrix-geometric method. Numerical results are also presented. AMS Subject Classification number: 60k25 and 65k30

scholarly journals FORMULATION AND EVALUATION OF ORMELOXIFENE FAST DISSOLVING TABLETS

2018 ◽  
Vol 6 (3) ◽  
pp. 17-31
Author(s):  
Abdul Hasan Sathali ◽  
Ramanathan M
Keyword(s):  
Solid Dispersion ◽  
Research Work ◽  
Solvent Evaporation ◽  
Water Soluble ◽  
Two Phase ◽  
Evaporation Technique ◽  
Co Precipitation ◽  
Phase Process

The objective of the present work was to enhancedissolution and solubility of slightly water soluble ormeloxifene hydrochloride and formulate fast dissolving tablets. The research work was two-phase process, the first phase was to enhance the solubility and dissolution of ormeloxifene. For this object drugwas processed with different solid dispersion techniques like kneading, co precipitation, melting and solvent evaporation technique with

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