• 품질경영학회지
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• 제19권2호
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• pp.145-157
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• 1991

Thid study intends to pursue behavioral-structure of production behavior through statistical models which are using in PERT and Queueing theory. We can corprehand the orders of human production behavior's characteristics by several related attributes of probablity/statistics. These attributes are poisson, Beta, exponential distributions and P.S Laplace's natural probability. Human production behavior is related and regressed to these attributes in many divisions intermediately. Progressive numerical understanding in many essential human behavior acts on the application of practical behavior standard in production word and operation.

• Journal of Communications and Networks
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• 제17권3호
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• pp.265-266
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• 2015

In a recent paper [1], the authors investigated the maximum stable throughput region of a network composed of a rechargeable primary user and a secondary user plugged to a reliable power supply. The authors studied the cases of an infinite and a finite energy queue at the primary transmitter. However, the results of the finite case are incorrect. We show that under the proposed energy queue model (a decoupled M/D/1 queueing system with Bernoulli arrivals and the consumption of one energy packet per time slot), the energy queue capacity does not affect the stability region of the network.

• 산업경영시스템학회지
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• 제6권8호
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• pp.93-103
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• 1983

In this paper, we study an optimal service policy of the M/M/2/K queueing system with two types of customers. The incurred costs consist of waiting cost, service cost and incurred costs consist of waiting cost, service cut and changeover cost. The changeover cost occurs when a server who assigned to serve a particular type of customers reassigned to the other types of customers. Two servers serve two types of customers who arrive to the two separate queues. The two types of customers differ in respect of their arrival rate, service rate, waiting cost, and service cost. The servers require a policy, for determining when they should change their service type, which minimizes the long run expected total cost. The policy is obtained by a Markov decision process model that consists of a finite number of states and actions. In order to find the optimal service policy, we define states and actions of the system, compute onestep transition probabilities, and apply to the successive approximations algorithm.

• 한국시뮬레이션학회논문지
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• 제13권3호
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• pp.1-10
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• 2004

The cell loss probability required in the ATM network is in the range of 10$^{-9}$ ∼10$^{-12}$ . If Monte Carlo simulation is used to analyze the performance of the ATM node, an enormous amount of computer time is required. To obtain large speed-up factors, importance sampling may be used. Since the Markov-modulated processes have been used to model various high-speed network traffic sources, we consider discrete time single server queueing systems with Markov-modulated arrival processes which can be used to model an ATM node. We apply importance sampling based on the Large Deviation Theory for the performance evaluation of, MMBP/D/1/K, ∑MMBP/D/1/K, and two stage tandem queueing networks with Markov-modulated arrival processes and deterministic service times. The simulation results show that the buffer overflow probabilities obtained by the importance sampling are very close to those obtained by the Monte Carlo simulation and the computer time can be reduced drastically.

• 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.

• 한국시뮬레이션학회논문지
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• 제9권2호
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• pp.89-102
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• 2000

In this paper, we consider an optimal allocation of constant service efforts in queueing network to maximize the system throughput. For this purpose, using the perturbation analysis, we apply a stochastic optimization algorithm to two types of queueing systems. Our simulation results indicate that the estimates obtained from a stochastic optimization algorithm for a two-tandem queuing network are very accurate, and those for closed loop manufacturing system are a little apart from the known optimal allocation. We find that as simulation time increases for obtaining a new gradient (performance measure with respect to decision variables) by perturbation algorithm, the estimates tend to be more stable. Thus, we consider that it would be more desirable to have more accurate sensitivity of performance measure by enlarging simulation time rather than more searching steps with less accurate sensitivity. We realize that more experiments on various types of systems are needed to identify such a relationship with regards to stopping rule, the size of moving step, and updating period for sensitivity.

• 한국통신학회논문지
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• 제12권2호
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• pp.92-101
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• 1987

통신망에 입력하는 메시지는 그 메시지에 부과되는 우선도에 의하셔 큐잉(Queueing)되며 큐(Queue)에서의 우선도는 여러가지 방법으로 취급되어진다. 이 연구는 메시지 처리의 한 방법인 동적 우선도(dynamic priority)에 관한 것으로 메시지의 평균 대기 시간에 관한 해석이다. 큐에서의 메시지의 대기 시간에 따라 우선도가 변하는 동적 우선도의 가변성은 그 메시지가 초기 우선도(initial priority)를 가지고 입력되는 경우가 초기우선도를 가지지 않는 경우 달라지는 것으로 특히 그 차이점을 고찰하였다.

• 산업경영시스템학회지
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• 제30권1호
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• pp.33-40
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• 2007

A multi-server queueing system with finite buffer is considered. The input flow is the BMAP (Batch Markovian Arrival Process). The service time has the PH (Phase) type distribution. Customers from the BMAP enter the system according to the discipline of partial admission. Besides ordinary (positive) customers, the Markovian flow (MAP) of negative customers arrives to the system. A negative customer can delete an ordinary customer in service if the state of its PH-service process belongs to some given set. In opposite case the ordinary customer is considered to be protected of the effect of negative customers. The stationary distribution and the main performance measures of the considered queueing system are calculated.

• 산업경영시스템학회지
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• 제32권4호
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• pp.161-168
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• 2009

The most generalized form of the triadic operating policy for an M/G/1 queueing model is developed. It consists of three simple N, T and D operating policies and has a peculiar structure possessing concepts of dyadic policies. Using the concept of the pseudo probability density function of the busy period, its expected busy period for the controllable M/G/1 queueing model is derived. Since the obtained result is the most generalized form the triadic polity, the expected busy periods for all known dyadic policies are recovered as special cases from it.

• 한국통신학회논문지
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• 제25권9A호
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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.