• 한국경영과학회지
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• 제24권4호
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• pp.111-122
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• 1999

In this paper, we consider a queueing network model. where the population constraint within each subnetwork is controlled by a semaphore queue. The total number of customers that may be present in the subnetwork can not exceed a given value. Each node has a constant service time and the arrival process to the queueing network is an arbitrary distribution. A major characteristics of this model is that the lower layer flow is halted by the state of higher layer. We present some properties that the inter-change of nodes does not make any difference to customer's waiting time in the queueing network under a certain condition. The queueing network can be transformed into a simplified queueing network. A dramatic simplification of the queueing network is shown. It is interesting to see how the simplification developed for sliding window flow control, can be applied to multi-layered queueing network.

• 한국경영과학회지
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• 제25권1호
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• pp.15-26
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• 2000

We consider an open tandem queueing network with population constraint and constant service times. The total number of customers that may be present in the network can not exceed a given value k. Customers arriving at the queueing network when there are more than k customers are forced to walt in an external queue. The arrival process to the queueing network is assumed to be arbitrary. It is known that the queueing network with population constrant and constant service times can be transformed into a simple network involving only two nodes. In this paper, the departure process from the queueing network is examined using this simple network. An approximation can be calculated with accuracy. Finally, validations against simulation data establish the tightness of these.

• 한국경영과학회지
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• 제34권4호
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• pp.113-121
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• 2009

In this paper, we consider the departure process from the open and nested tandem Queueing network with population constraint and constant service times. It is known that the Queueing network can be transformed into a simple Queueing network which can be easy to analyze. Using this simple Queueing network, upper and lower bounds on the interdeparture time are obtained. We prove that the variance of the interdeparture time is bounded within these two bounds. Validation against simulation data is shown that how it works the variance of the interdeparture time within two bounds. These bounds can be applied to obtain the better variance of the interdeparture time using a suitable method.

• 한국시뮬레이션학회논문지
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• 제1권1호
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• pp.48-54
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• 1992

This study discusses the performance evaluation of queueing network methodologies as used for the planning of FMS production systems. The possibility of applications and utilities of queueing network models is investigated for FMS producton plans. Experimental results by queueing network models such as CAN-Q, MVAQ and results by detailed simulation models written in SIMAN are compared and some propositions are presented based on the results of the experiments.

• 한국정보과학회논문지:시스템및이론
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• 제36권4호
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• pp.239-246
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• 2009

각 계층 네트워크가 세마포에 의하여 용량제한을 갖는 중첩형 대기행렬 네트워크의 평균대기시간에 관하여 연구하였다. 중첩형 대기행렬 네트워크는 고객의 대기시간 관점에서 보다 간단한 대기행렬 네트워크로 변환될 수 있다. 이러한 중첩형 대기행렬 네트워크의 가장 중요한 특성은 하위계층의 흐름이 상위 계층의 상태에 의존적이며, 제한을 받는다는 것이다. 이러한 형태의 대기행렬 네트워크는 성능분석을 정확히 할 수 없기 때문에, 변환된 중첩형 대기행렬 네트워크를 이용하여 평균대기시간에 대한 하한과 상한을 분석하고자 한다. 모의실험에 관한 측정은 도착분포가 단계형태 분포로서 포아송, 얼랑 그리고 초지수분포에 관하여 조사하였다. 이렇게 구한 범위는 추후에 좀 더 근접한 근사치를 구하는데 이용할 수 있다.

• 제어로봇시스템학회논문지
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• 제8권4호
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• pp.288-291
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• 2002

We characterize multipath fading channel dynamics at the packet level and analyze the corresponding data queueing performance in various environments. We identify the similarity between wire-line queueing analysis and wireless network per-formance analysis. The second order channel statistics, i.e. channel power spectrum, is fecund to play an important role in the modeling of multipath fading channels. However, it is identified that the first order statistics, i.e. channel CDF also has significant impact on queueing performance. We use a special Markov chain, so-called CMPP, throughout this paper.

• 한국통신학회논문지
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• 제15권7호
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• pp.602-617
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• 1990

본 논문에서는 CCITT에서 권고된 종합 정보 통신망(Integrated Service Digital Network:ISDN)에서의 가입자와 망간의 접속에 있어 S-기준점에서의 D-채널 엑세스 프로토콜의 성능을 분석하였다. 먼저 여러대의 단말이 멀티 포인트로 D-채널을 액세스하는 경우의 D-채널 엑세스 프로토콜의 queueing 모델을 세웠다. 그리고 지연 요소를 waiting queue지연과 경쟁 지연으로 구분하고, 다시 경쟁 지연을 모효 경쟁 지연과 순수 경쟁 지연으로 자누어 해석하므로서 대칭 또는 비대칭의 평균 도착률을 가진 우선도 서비스의 queueing시스템에 모두 적용할 수 있도록 하였다. 또한 대칭 시스템과 비대칭 시스템에 대한 수치 결과를 얻어, 한 단말에서 모든 정보가 지선제 우선도로 서비스되는 queueing 시스템과 비교하였다.

• 한국경영과학회지
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• 제31권1호
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• pp.1-13
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• 2006

In this paper we consider a design problem of a cyclic queueing network with two stages, each with a local buffer of limited capacity. Based on the theory of reversibility and product-form solution, we derive the throughput function of the network as a key performance measure to maximize. Two cases are considered. In case each stage consists of a single server, an optimal allocation policy of a given buffer capacity and work load between stages as well as the optimal number of customers is identified by exploiting the properties of the throughput function. In case each stage consists of multiple servers, the optimal policy developed for the single server case doesn't hold any more and an algorithm is developed to allocate with a small number of computations a given number of servers, buffer capacity as well as total work load and the total number of customers. The differences of the optimal policies between two cases and the implications of the results are also discussed. The results can be applied to support the design of certain manufacturing and computer/communication systems.

• 한국경영과학회지
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• 제28권1호
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• pp.37-49
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• 2003

Using the concept of closed queueing network, we present a consistent way of interpreting existing duality relations among queueing systems. Also, using embedded Markov chains, we present a few new duality relations for the queueing systems with negative customers.

• East Asian mathematical journal
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• 제31권5호
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• pp.707-716
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• 2015

We consider a queueing system with N-limited nonstop forwarding. In this queueing system, when the server breaks down, up to N customers can be serviced during the repair time. It can be used to model an assembly line consisting of several automatic stations and a manual backup station. Within the framework of $Geo^X/D/1$ queue, the matrix analytic approach is used to obtain the performance of the system. Some numerical examples are provided.