• 제목/요약/키워드: Queue Length Distribution

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Estimating the Queue Length Distribution of ATM multiplexer using Threshold Bootstrap

  • 김윤배
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 1999년도 추계학술대회 논문집
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    • pp.62-62
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    • 1999
  • In this paper, we propose a new technique of estimating tail of steady-state queue length distribution; Pr(Q>q), fo ATM multiplexer. Pr(Q>q) is a fundamental measure of network congestion. Assessing Pr(Q>q) properly is crucial for design and control of ATM networks. Data traffic pattern of high-speed networks is highly correlated and bursty. Estimating Pr(Q>q) is very difficult because of correlation and burstiness. We estimate entropy(rate-function) using large deviation principles and threshold bootstrap. Simulation studies are conducted to compare the performance of an existing method and our new method.

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Stochastic Upper Bound for the Stationary Queue Lengths of GPS Servers

  • Kim, Sung-Gon
    • 응용통계연구
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    • 제22권3호
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    • pp.541-551
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    • 2009
  • Generalized processor sharing(GPS) service policy is a scheduling algorithm to allocate the bandwidth of a queueing system with multi-class input traffic. In a queueing system with single-class traffic, the stationary queue length becomes larger stochastically when the bandwidth (i.e. the service rate) of the system decreases. For a given GPS server, we consider the similar problem to this. We define the monotonicity for the head of the line processor sharing(HLPS) servers in which the units in the heads of the queues are served simultaneously and the bandwidth allocated to each queue are determined by the numbers of units in the queues. GPS is a type of monotonic HLPS. We obtain the HLPS server whose queue length of a class stochastically bounds upper that of corresponding class in the given monotonic HLPS server for all classes. The queue lengths process of all classes in the obtained HLPS server has the stationary distribution of product form. When the given monotonic HLPS server is GPS server, we obtain the explicit form of the stationary queue lengths distribution of the bounding HLPS server. Numerical result shows how tight the stochastic bound is.

Exact Asymptotics in a Multi-class M/G/1 Queue

  • 이지연
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2006년도 PROCEEDINGS OF JOINT CONFERENCEOF KDISS AND KDAS
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    • pp.43-47
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    • 2006
  • Consider a multitype queue where queued customers arc served in their order of arrival at a rate which depends on the customer type. Here we calculate the sharp asymptotics of the probability the total number of customers in the queue reaches a high level before emptying. The natural state space to describe this queue is a tree whose branches increase in length as the number of customers in the queue grows. Consequently it is difficult to prove a large deviation principle. Moreover, since service rates depend on the customer type the stationary distribution is not of product form so there is no simple expression for the stationary distribution. Instead, we use a change of measure technique which increases the arrival rate of customers and decreases the departure rate thus making large deviations common.

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휴가기간이 고객의 도착에 영향을 받는 휴가형 우선순위 M/G/1 대기행렬 분석 (Analysis of the M/G/1 Priority Queue with vacation period depending on the Customer's arrival)

  • 정보영;박종훈;백장현;이창훈
    • 산업공학
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    • 제25권3호
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    • pp.283-289
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    • 2012
  • M/G/1 queue with server vacations period depending on the previous vacation and customer's arrival is considered. Most existing studies on M/G/1 queue with server vacations assume that server vacations are independent of customers' arrival. However, some vacations are terminated by some class of customers' arrival in certain queueing systems. In this paper, therefore, we investigate M/G/1 queue with server vacations where each vacation period has different distribution and vacation length is influenced by customers' arrival. Laplace-Stieltjes transform of the waiting time distribution and the distribution of number of customers waiting for each class of customers are respectively derived. As performance measures, mean waiting time and average number of customers waiting for each class of customers are also derived.

시스템 내 고객 수에 따라 서비스율과 도착율을 조절하는 M/G/1/K 대기행렬의 분석 (Analysis of an M/G/1/K Queueing System with Queue-Length Dependent Service and Arrival Rates)

  • 최두일;임대은
    • 한국시뮬레이션학회논문지
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    • 제24권3호
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    • pp.27-35
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    • 2015
  • 대기행렬 시스템에는 고객들의 대기시간이 지나치게 길어지는 것을 막기 위해 다양한 정책들이 적용되는데, 본 연구에서는 고객숫자에 따른 제어 정책을 갖는 유한용량 M/G/1/K 대기행렬을 분석한다. 고객의 숫자에 따라 서버의 서비스율과 고객의 도착율을 조절하는 정책이다. 두 개의 한계점(thresholds) $L_1$$L_2$($${\geq_-}$$L1)를 설정하고 시스템 내 고객의 숫자가 $L_1$보다 작을 때는 시스템은 보통(또는 상대적으로 느린)의 서비스율(service rate)과 보통의 도착율(arrival rate)을 갖는다. 고객의 숫자가 증가하여 $L_1$이상이고 $L_2$보다 작으면 도착율은 그대로 이지만 서비스율을 증가시켜 빠르게 서비스한다. 이후 고객의 숫자가 더욱 증가하여 $L_2$ 이상이면 고객의 도착율도 작은 값으로 바꾸어 고객을 덜 입장시킨다. 위 정책을 갖는 M/G/1/K 대기행렬을 내재점 마코프 체인과 준-마코프 과정을 이용하여 분석하고 수치예제를 제시한다.

고객수 기반의 오버로드 제어 정책이 있는 M/G/1/K 대기행렬의 바쁜기간 분석 (Busy Period Analysis of an M/G/1/K Queue with the Queue-Length-Dependent Overload Control Policy)

  • 임헌상;임대은
    • 한국시뮬레이션학회논문지
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    • 제27권3호
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    • pp.45-52
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    • 2018
  • 대기행렬에 고객 (또는 패킷 등)이 몰리는 오버로드(overload)가 발생하는 경우 긴 대기열이 발생하여 서비스 품질에 좋지 않은 영향을 줄 수 있다. 오버로드 상황에서 혼잡을 완화하기 위해 대기하는 고객숫자에 기반한 다양한 오버로드 제어 정책들이 고안, 적용되고 있다. 본 연구는 대기 중인 고객 숫자에 한계점 (threshold)을 두고, 한계점을 넘으면 서비스 속도를 빠르게 하거나 고객의 도착 간격(시간)을 증가시키는 제어정책을 대상으로 한다. 이러한 정책을 갖는 M/G/1 대기행렬에 대해 바쁜 기간(busy period)을 분석하는데, 연구결과는 비용구조가 주어졌을 때 최적 시스템 제어 정책을 찾는데 필수적이다.

워킹 휴가형 GI/M/1 대기행렬의 바쁜기간 분석 (Busy Period Analysis for the GI/M/1 Queue with Working Vacations)

  • 채경철;임대은
    • 한국경영과학회지
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    • 제32권2호
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    • pp.141-147
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    • 2007
  • We consider a GI/M/1 queue with vacations such that the server works with different rate rather than completely stops working during a vacation period. We derive the transform of the joint distribution of the length of a busy period, the number of customers served during the busy period, and the length of the subsequent idle period.

Proposal of Approximation Analysis Method for GI/G/1 Queueing System

  • Kong, Fangfang;Nakase, Ippei;Arizono, Ikuo;Takemoto, Yasuhiko
    • Industrial Engineering and Management Systems
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    • 제7권2호
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    • pp.143-149
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    • 2008
  • There have been some approximation analysis methods for a GI/G/1 queueing system. As one of them, an approximation technique for the steady-state probability in the GI/G/1 queueing system based on the iteration numerical calculation has been proposed. As another one, an approximation formula of the average queue length in the GI/G/1 queueing system by using the diffusion approximation or the heuristics extended diffusion approximation has been developed. In this article, an approximation technique in order to analyze the GI/G/1 queueing system is considered and then the formulae of both the steady-state probability and the average queue length in the GI/G/1 queueing system are proposed. Through some numerical examples by the proposed technique, the existing approximation methods, and the Monte Carlo simulation, the effectiveness of the proposed approximation technique is verified.

PERFORMANCE ANALYSIS OF THE LEAKY BUCKET SCHEME WITH QUEUE LENGTH DEPENDENT ARRIVAL RATES

  • Choi, Doo-Il;Lee, Sang-Min
    • 대한수학회보
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    • 제43권3호
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    • pp.657-669
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    • 2006
  • In this paper, we analyze a leaky bucket (LB) scheme with queue length dependent arrival rates. In other words, if the queue length exceeds an appropriate threshold value on buffer, the arrivals need to be controlled. In ATM networks, if the congestion occurs, the input traffics must be controlled (reduced) for congestion resolution. By the bursty and correlated properties of traffics, the arrivals are assumed to follow a Markov-modulated Poisson process (MMPP). We derive the loss probability and the waiting time distribution for arbitrary cell. The analysis is done by using the embedded Markov chain and supplementary variable method. We also present some numerical examples to show the effects of our proposed LB scheme.

여러개의 two-state MMPP 입력을 갖는 대기체계에 대한 계산방법 (Analysis of MMPP/M/1 Queue with several homogeneous two-state MMPP sources)

  • 이계민;안수한;전종우
    • 한국통신학회논문지
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    • 제24권9A호
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    • pp.1354-1358
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    • 1999
  • In this paper, we suggest a simple computational algorithm to obtain the queue length distribution in the finite queue, where the input process consists of several homogeneous two-state Markov modulated Poisson processes. With comparison to the conventional algorithm, is more practical, in particular, when a large number of input sources are loaded to the system.

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