scholarly journals APPLICATION OF NON PREEMPTIVE PRIORITY QUEUING FOR BASRAH COMMERCIAL PORTS

2019 ◽  
Vol 24 (3) ◽  
Author(s):  
Huda Zaki Naji ◽  
Suaad Abdul Razzaq ◽  
, Samaher Adnan
Keyword(s):  
Sustainable Development ◽  
Waiting Time ◽  
Priority Queues ◽  
Preemptive Priority ◽  
Multiple Servers

Waiting for commercial vessels inside the port is one of the most important problems facing traders and offshore companies, which often lead to material losses. The ports of Basrah are characterized by continuous congestion, which leads to the diversion of ships to the ports of the neighboring countries, causing the loss of many revenues to the country. This paper emphasizes the importance of non-preemptive priority queues (with multiple servers and multiple priority classes) to the problem of congestion of ports in order to promote sustainable development of the ports of Basrah. The aim of this paper is to apply a non-preemptive priority queues at ports of Basrah and calculating the average customer waiting time for the ships at berths.                    

scholarly journals Preemptive priority queues

1963 ◽  
Vol 3 (4) ◽  
pp. 491-502 ◽  
Author(s):  
G. F. Yeo
Keyword(s):  
Waiting Time ◽  
Busy Period ◽  
Priority Queues ◽  
Poisson Processes ◽  
Size Distributions ◽  
Queue Size ◽  
Preemptive Priority ◽  
Preemptive Resume ◽  
Stationary Waiting Time

SummaryIn this paper priority queues with K classes of customers with a preemptive repeat and a preemptive resume policy are considered. Customers arrive in independent Poisson processes, are served, within classes, in order of arrival, and have general requirements for service. Transforms of stationary waiting time and queue size distributions and busy period distributions are obtained for individual classes and for the system; the moments of the distributions are considered.

WAITING TIME ANALYSIS OF MULTI-CLASS QUEUES WITH IMPATIENT CUSTOMERS

2013 ◽  
Vol 27 (3) ◽  
pp. 333-352 ◽  
Author(s):  
Vahid Sarhangian ◽  
Bariş Balciog̃lu
Keyword(s):  
Waiting Time ◽  
Delay Systems ◽  
Single Server ◽  
Impatient Customers ◽  
Preemptive Priority ◽  
System A ◽  
Virtual Waiting Time ◽  
The Laplace Transform ◽  
Time Requirements ◽  
Priority Policy

In this paper, we study three delay systems where different classes of impatient customers arrive according to independent Poisson processes. In the first system, a single server receives two classes of customers with general service time requirements, and follows a non-preemptive priority policy in serving them. Both classes of customers abandon the system when their exponentially distributed patience limits expire. The second system comprises parallel and identical servers providing the same type of service for both classes of impatient customers under the non-preemptive priority policy. We assume exponential service times and consider two cases depending on the time-to-abandon distribution being exponentially distributed or deterministic. In either case, we permit different reneging rates or patience limits for each class. Finally, we consider the first-come-first-served policy in single- and multi-server settings. In all models, we obtain the Laplace transform of the virtual waiting time for each class by exploiting the level-crossing method. This enables us to compute the steady-state system performance measures.

scholarly journals Social welfare and price of anarchy in preemptive priority queues

2020 ◽  
Vol 48 (4) ◽  
pp. 530-533 ◽  
Author(s):  
Jonathan Chamberlain ◽  
David Starobinski
Keyword(s):  
Social Welfare ◽  
Price Of Anarchy ◽  
Priority Queues ◽  
Preemptive Priority

scholarly journals Performance Modeling of Proposed GUISET Middleware for Mobile Healthcare Services in E-Marketplaces

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Alaba Olu Akingbesote ◽  
Mathew Olusegun Adigun ◽  
Sibisuso Xulu ◽  
Edgar Jembere
Keyword(s):  
South Africa ◽  
Waiting Time ◽  
Queuing Theory ◽  
Performance Modeling ◽  
Healthcare Services ◽  
Pricing Strategy ◽  
Preemptive Priority ◽  
Mobile Healthcare ◽  
Utility Services ◽  
Priority Model

GUISET is a proposed middleware engine currently under study in South Africa. The goal is to provide utility services for small, medium, and macroenterprises in the context of mobile e-services. Three things are important to make this engine effective and efficient: the implementation, performance, and the pricing strategy. The literature has delved richly into implementation issue of similar projects. Both the performance and the pricing strategy issues have not been fully discussed especially in the context of mobile healthcare services. Some literature has addressed the performance issue using the exogenous nonpriority and the preemptive model. However, with providers offering different services using that approach may prove to be difficult to implement. This work extends existing and widely adopted theories to non-preemptive model by using the queuing theory and the simulation model in the context of mobile healthcare services. Our evaluation is based on non-preemptive priority and nonpriority discipline. Our results reveal that the unconditional average waiting time remains the same with reduction in waiting time over the non-preemptive priority model in four out of the five classes observed. This is envisaged to be beneficial in mobile healthcare services where events are prioritized and urgent attention is needed to be given to urgent events.

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