• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1377-1386
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• 2000

As all delays resulting from the signaling network directly affect the response time of network management activity, all control informations have to be transported most efficiently. It is very important to know the performance of the signaling system not only because of smooth network operation but also because of efficient engineering of signaling networks. In this paper, we analyzed mean queueing delay of signaling link for ISUP signaling messages in common channel signaling system by using M[X]/G/1 and M[X]/D/1 batch arrival queueing system. This is because we modeled arrival process of the signaling messages as batch arrival process considering that many kinds of signaling messages are generated at short intervals when a call requests a connection. Analysis was carried out considering different call processing scenario based on ITU-T specification. We also described the numerical results from the different types of queueing models.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.153-165
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• 1995

Many closed queueing network models have been used as an effective tool to make a preliminary design of FMS. Although a loading/unloading function is an important factor to effect the utilization and throughput of FMS as well as a transfer function and a processing function, the Solberg's model did not clarify the loading/unloading function. In this paper, we propose a closed queueing network model for analyzing a flexible manufacturing system that consists of a load/unload station, a material handling system and a group of workstations for processing jobs, and define the expected utilization and the expected throughput of the FMS. As applications of the proposed model, the cases of a material handling system consisting of a conveyor and the FMS including an inspection station are also formulated.

• The Journal of the Korea Contents Association
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• v.5 no.4
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• pp.245-253
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• 2005

The multimedia ad hoc wireless network is quite an attractive issue since it offers a flexible solution to enable delivery of multimedia services to mobile end users without fixed backbone networks. However, with the unique design challenges of ad hoc wireless networks, it is a non-trivial issue to provide bounded delay guarantee, with fair share of resources. In this paper, we proposed distributed implementation of the delay guaranteed fair queueing (DGFQ) scheme in multimedia ad hoc wireless networks. Through the the results of performance evaluation, we can conclude that DGFQ also performs well to control bounded delay in multimedia ad hoc wireless networks.

• Korean Management Science Review
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• v.27 no.1
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• pp.17-31
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• 2010

Patients entering an emergency care center in a hospital usually visit medical processes in different orders depending on the urgency level and the medical treatments required. We formulate the patient flows among diverse processes in an emergency care center using the Jackson network, which is one of the queueing networks, in order to evaluate the system performances such as the expected queue length and the expected waiting time. We present a case study based on actual data collected from an emergency care center in a hospital, in order to prove the validity of applying the Jackson network model in practice. After assessing the current system performances, we provide operational strategies to reduce waiting at the bottleneck processes and evaluate the impact of those strategies on the entire system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.6
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• pp.545-553
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• 1987

An approximation algorithm has been obtained to analyze the network of single server tandem queues with a finite length. In the queueing network with a finite queue length, the blocking which is mutually dependent, occure due to the limitation of the queue length. Thus, it is difficults to analyze such a queueing network. In this paper each queue has been regarded as the independent M/M/1/K system to analyze the queueing network with the blocking, which is based on the assumption that an arrival rate to the present station is increased by the blocking of the following stations. The performance measures, such as state probability, average queue length and tha waiting time, can be easily obtained using the proposed algorithm. In order to justify this approximation algorithm, comparison of the results of this algorithm with those of state transition simultaneous equations has been made an verified with computer simulation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.4
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• pp.39-45
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• 2007

The BMAP/M/N/0 queueing system operating in Markovian random environment is investigated. The stationary distribution of the system is derived. Loss probability and other performance measures of the system also are calculated. Numerical experiments which show the necessity of taking into account the influence of random environment and correlation in input flow are presented.

• The KIPS Transactions:PartA
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• v.9A no.1
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• pp.45-52
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• 2002

This paper proposes the fuzzy closed RCMP queueing network model using fuzzy set theory for the performance evaluation of centralized distributed processing system with ambiguous system factors in the network environments. This model can derive the measures for system performances such as the job spending time, the system throughput, average job number and server utilizations using fuzzy mean value analysis which can process the fuzzy factors. Computer simulation has been performed centralized distributed system with fuzzy service requirement time for verifying the effectiveness of derived equations of performance evaluation according to the numbers of clients, and the results were analyzed. The proposed model provides more and flexible realistic than performance evaluation of conventional method when we evaluated system performance with ambiguous factors.

• Journal of the military operations research society of Korea
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• v.6 no.2
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• pp.47-67
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• 1980

Interactions of major activities participating in fleet operations are investigated in the framework of a closed queueing network system with finite aircrafts assigned to it. An implementable algorithm is developed, which is useful for computing the distributions needed to evaluate the effects of the interactions on the fleet operations. The availability management program is focused on seeking an optimal resource allocation to multiple repair-shops to maximize the fleet availability subject to the budget constraint.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.22
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• pp.87-98
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• 1990

The performance analysis and capacity planning of Service Control Point which is real time response system is studied. The system is modeled by multiclass open queueing network. The analytical method is used to solve the queueing network. The solution of the model has product form solution. The focus of this paper is to investigate the capacity of system under the restriction of response time. To get the reasonable capacities, nonlinear programming problem is formulated and is solved by GINO. And the simulation model using SLAM II is formulated.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.3
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• pp.319-330
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• 2002

We consider BMAP/G/1 queueing system with N-policy and multiple vacations. We derive the vector generating functions of the queue length in a factorized form and interpret the factorization. We also derive the mean queue length.