scholarly journals Analysis of Multi-Server Queue with Self-Sustained Servers

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2134
Author(s):  
Alexander Dudin ◽  
Olga Dudina ◽  
Sergei Dudin ◽  
Konstantin Samouylov

A novel multi-server vacation queuing model is considered. The distinguishing feature of the model, compared to the standard queues, is the self-sufficiency of servers. A server can terminate service and go on vacation independently of the system manager and the overall situation in the system. The system manager can make decisions whether to allow the server to start work after vacation completion and when to try returning some server from a vacation to process customers. The arrival flow is defined by a general batch Markov arrival process. The problem of optimal choice of the total number of servers and the thresholds defining decisions of the manager arises. To solve this problem, the behavior of the system is described by the three-dimensional Markov chain with the special block structure of the generator. Conditions for the ergodicity of this chain are derived, the problem of computation of the steady-state distribution of the chain is discussed. Expressions for the key performance indicators of the system in terms of the distribution of the chain states are derived. An illustrative numerical result is presented.

2006 ◽  
Vol 132 (5) ◽  
pp. 578-589 ◽  
Author(s):  
P. P. Bocharov ◽  
R. Manzo ◽  
A. V. Pechinkin

2005 ◽  
Vol 131 (3) ◽  
pp. 5606-5613 ◽  
Author(s):  
P. P. Bocharov ◽  
R. Manzo ◽  
A. V. Pechinkin

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Ali Delavarkhalafi

<p style='text-indent:20px;'>In this paper, a queuing system as multi server queue, in which customers have a deadline and they request service from a random number of identical severs, is considered. Indeed there are stochastic jumps, in which the time intervals between successive jumps are independent and exponentially distributed. These jumps will be occurred due to a new arrival or situation change of servers. Therefore the queuing system can be controlled by restricting arrivals as well as rate of service for obtaining optimal stochastic jumps. Our model consists of a single queue with infinity capacity and multi server for a Poisson arrival process. This processes contains deterministic rate <inline-formula><tex-math id="M1">\begin{document}$ \lambda(t) $\end{document}</tex-math></inline-formula> and exponential service processes with <inline-formula><tex-math id="M2">\begin{document}$ \mu $\end{document}</tex-math></inline-formula> rate. In this case relevant customers have exponential deadlines until beginning of their service. Our contribution is to extend the Ittimakin and Kao's results to queueing system with impatient customers. We also formulate the aforementioned problem with complete information as a stochastic optimal control. This optimal control law is found through dynamic programming.</p>


2001 ◽  
Vol 15 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Arie Hordijk

Traveling times in a FIFO-stochastic event graph are compared in increasing convex ordering for different arrival processes. As a special case, a stochastic lower bound is obtained for the sojourn time in a tandem network of FIFO queues with a Markov arrival process. A counterexample shows that the extended Ross conjecture is not true for discrete-time arrival processes.


2019 ◽  
Vol 51 (4) ◽  
pp. 1179-1208 ◽  
Author(s):  
Jose Blanchet ◽  
Yanan Pei ◽  
Karl Sigman

AbstractUsing a result of Blanchet and Wallwater (2015) for exactly simulating the maximum of a negative drift random walk queue endowed with independent and identically distributed (i.i.d.) increments, we extend it to a multi-dimensional setting and then we give a new algorithm for simulating exactly the stationary distribution of a first-in–first-out (FIFO) multi-server queue in which the arrival process is a general renewal process and the service times are i.i.d.: the FIFO GI/GI/c queue with $ 2 \leq c \lt \infty$ . Our method utilizes dominated coupling from the past (DCFP) as well as the random assignment (RA) discipline, and complements the earlier work in which Poisson arrivals were assumed, such as the recent work of Connor and Kendall (2015). We also consider the models in continuous time, and show that with mild further assumptions, the exact simulation of those stationary distributions can also be achieved. We also give, using our FIFO algorithm, a new exact simulation algorithm for the stationary distribution of the infinite server case, the GI/GI/ $\infty$ model. Finally, we even show how to handle fork–join queues, in which each arriving customer brings c jobs, one for each server.


2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.


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