• Title, Summary, Keyword: 평균 대기 시간

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Dynamic Control of Coordinated Traffic Signals for Minimizing Queue-lengths (대기 차량 최소화를 위한 동적 교통 신호연동 모델)

  • 윤경섭
    • Proceedings of the KOR-KST Conference
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    • pp.196-205
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    • 1998
  • 교통신호에서 주로 고려되는 변수는 신호주기(cycle length), 녹색시간(green split), 옵셋(offset)그리고 좌회전 현시순서(left-turn phase sequence)로 구성된다. 기존의 대부분의 연동 모델들은 고정된 주기하에서 평균적인 유입 교통량을 측정한 후, 선형최적화 이론을 적용하여 최적 신호를 산출한다. 그러나 이 방법은 어디까지나 평균적인 데이터에 대해서 계산을 한 것이기 때문에 실시간 최적화를 제공하기가 어렵다. 본 연구에서는 평균 차량 통행량 대신 실시간으로 입력되는 차량 대기행렬, 차량 도착률을 기초로 대기차량을 최소화하는 동적 신호시간 산출 모델을 개발하였다. 본 모델에서는 Peytechew가 제안한 각 진입로에서의 대기 차량 예측 모델을 기초로 하여 다음 주기에서의 차량 대기 행렬을 예측한 후, 선형 최적화 이론을 적용하여 신호시간을 산출한다. 본 모델에서 산출된 신호주기와 녹색시간은 대기차량길이를 최소화하는 신호 시간으로서 교차로간의 연동효과를 고려하여 실시산 교통상황에 따라 주기별로 변화한다. 본 모델은 3개의 교차로로 구성된 네트워크를 대상으로 적용하였다. 실험 네트워크의 주도로 교통량은 부도로의 교통량 보다 많다고 가정하였으며 각 링크사이에서의 차량 진출입은 없다고 보았다.

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An Estimation of the Average Waiting Cost of Vessels Calling Container Terminals in Northern Vietnam (북베트남 컨테이너 터미널에 기항하는 선박의 평균대기비용 추정)

  • Nguyen, Minh-Duc;Kim, Sung-june
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.25 no.1
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    • pp.27-33
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    • 2019
  • Several studies have been completed on the topic of container terminals in Northern Vietnam. Few of them, however, deal with competition in terms of costs related to vessel waiting time or cargo handling. This paper estimates the average waiting cost per TEU for all the container terminals in Northern Vietnam. After average waiting time was first estimated by applying queuing theory, uncertainty theory was applied to estimated vessel daily cost. A simulation was performed to create a series of data representing waiting cost per TEU in relation to the rate of volume handled/capacity of each terminal. Non-linear regression based on this series was used to present a function for the relationship between the average waiting cost of each terminal and the rate of volume handled /capacity.

Workload and waiting time analysis of BMAP/G/1 queue under D-policy (D-정책을 갖는 BMAP/G/1 대기행렬 시스템의 일량 및 대기시간분석)

  • Baek Jeong-U;Lee Ho-U;Lee Se-Won;Kim Sang-An
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • pp.1093-1100
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    • 2006
  • 본 연구는 D-정책을 갖는 BMAP/G/1 대기행렬 시스템의 일량(workload) 및 대기시간(waiting time)을 분석한다. 유휴한 서버는 도착하는 고객들의 서비스 시간의 총합이 주어진 임계점 D를 넘어야만 서비스를 시작한다. 고객의 도착과정은 집단마코비안도착과정(BMAP, Batch Markovian Arrival Process)을 따른다. 본 논문에서는 이러한 시스템의 일량 및 대기시간에 대한 LST를 구하고, 이로부터 평균일량 및 평균대기시간을 유도한다. 또한 BMAP/G/1의 특별한 경우인 $M^X/G/1$인 경우와 대기시간의 비교를 행한다.

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Analysis of Average Waiting Time and Average Turnaround Time in Web Environment (웹 환경에서의 평균 대기 시간 및 평균 반환 시간의 분석)

  • Lee, Yong-Jin
    • The KIPS Transactions:PartC
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    • v.9C no.6
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    • pp.865-874
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    • 2002
  • HTTP (HyperText Transfer Protocol) is a transfer protocol used by the World Wide Web distributed hypermedia system to retrieve the objects. Because HTTP is a connection oriented protocol, it uses TCP (Transmission control Protocol) as a transport layer. But it is known that HTTP interacts with TCP badly. it is discussed about factors affecting the performance or HTTP over TCP, the transaction time obtained by the per-transaction TCP connections for HTTP access and the TCP slow-start overheads, and the transaction time for T-TCP (Transaction TCP) which is one or methods improving the performance or HTTP over TCP. Average waiting time and average turnaround time are important parameters to satisfy QoS (Quality of Service) of end users. Formulas for calculating two parameters are derived. Such formulas can be used for the environment in which each TCP or T-TCP transaction time is same or different. Some experiments and computational experiences indicate that the proposed formulas are well acted, can be applied to the environment which the extension of bandwidth is necessary, and time characteristics of T-TCP are superior to that of TCP. Also, the load distribution method of web server based on the combination of bandwidths is discussed to reduce average waiting time and average turnaround time.

Effect of Computing Procedure of Average a Daily Air Temperature on Frost Index determination (일평균 대기온도 산정방법이 동결지수 결정에 미치는 영향)

  • Cho, Myung-Hwan;Kim, Nakseok;Lee, Yoon-Han;Jin, Junghoon
    • 한국방재학회:학술대회논문집
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    • pp.83-83
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    • 2011
  • 도로의 동상방지층을 설치하기 위하여 동결관입깊이를 산정하며, 동결지수는 대기온도의 강도와 지속시간의 누가영향으로 표시된다. 대기온도는 일평균 대기온도를 사용하며 4개/일 평균(대기온도$_4$)을 사용하는 것이 일반적이지만, 현재 기상청에서 제공하고 있는 일평균 대기온도는 8개/일(대기온도$_8$)를 제공하고 있다. 이러한 일평균 대기온도의 산정하는 방법이 동결지수의 산정결과에 미치는 영향을 확인하기 위하여 한반도 남부지역(동결지수 $350^{\circ}C{\cdot}$일) 미만 6개지역을 저성토부, 절성경계부 및 절토부로 구분하여 15개소에 대하여 현장계측시스템을 구축하였다. 그리고 현장계측 시스템으로부터 얻어진 대기온도를 통하여 동결지수를 산정하여 비교하였다. 동결지수 비교결과 일반적으로 일평균 대기온도$_4$를 사용한 경우가 일평균 대기온도$_8$을 사용하는 경우보다 약 3% 전후 큰 것으로 나타나났으며, 6개 지역의 동결지수를 결정할 때 대기온도$_8$을 사용한 동결지수를 보정할 수 있는 보정식을 제안하였다.

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A Study on Left-turn Queues Analysis using Queueing Theory under Permissive Left-turn Signal System (비보호좌회전 신호체계운영에 따른 좌회전 대기행렬분석에 관한 연구)

  • Kim, Kap Soo;Jung, Ja Young
    • Journal of The Korean Society of Civil Engineers
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    • v.31 no.5D
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    • pp.663-669
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    • 2011
  • In this study, the optimal length of left-turn lane in permissive left-turn signal system at the signalized intersection which has a left-turn bay is estimated. It is a simulation analysis using the queueing theory that estimate the length of left-turn lane. Traffic density conform to the standards of operating a permissive left-turn system of the Practical Manual Traffic Safety Facilities. And each of a left-turn arrival rate, a left-turn service rate, left-turn average queueing time, for green time average queueing vehicle, for red time average queueing vehicle and average queueing vehicle cycle is calculated. As a result of this study, we would learn how much the space should be secured at the signalized intersection which has a left-turn bay. The methodology using the queueing theory to work out the optimal length of waiting lane in the permissive left-turn signal system was presented.

Development of Queue Length, Link Travel Time Estimation and Traffic Condition Decision Algorithm using Taxi GPS Data (택시 GPS데이터를 활용한 대기차량길이, 링크통행시간 추정 및 교통상황판단 알고리즘 개발)

  • Hwang, Jae-Seong;Lee, Yong-Ju;Lee, Choul-Ki
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.3
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    • pp.59-72
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    • 2017
  • As the part of study which handles the measure to use the individual vehicle information of taxi GPS data on signal controls in order to overcome the limitation of Loop detector-based collecting methods of real-time signal control system, this paper conducted series of evaluations and improvements on link travel time, queue vehicle time estimates and traffic condition decision algorithm from the research introduced in 2016. considering the control group and the other, the link travel time has enhanced the travel time and the length of queue vehicle has enhanced the estimated model taking account of the traffic situation. It is analyzed that the accuracy of the average link travel time and the length of queue vehicle are respectably both approximately 95 % and 85%. The traffic condition decision algorithm reflected the improved travel speed and vehicle length. Smoothing was performed to determine the trend of the traffic situation and reduce the fluctuation of the data, and the algorithms have refined so as to reflect the pass period on overflow judgment criterion.

An Adaptive Synchronization by Analyzing the Delay Time of Media (미디어 지연시간 분석에 의한 가변적 동기화)

  • Seo, Yeong-Geon;O, Hae-Seok;Sim, Jong-Chae;Kim, Ho-Yong;Kim, Hyeon-Ju
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.11
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    • pp.2801-2811
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    • 1997
  • This thesis Proposes a media synchronization mechanism for video conferencing system by analyzing a variation of the delay time of media. Using this mechanism, this thesis analyzes the media traffics and determines the values of external variables important on waiting time. This system uses some dummy streams to get the time. When two hosts are initially connected, they change the dummy streams by which a logical time of the sender may be extracted. The time presenting a media stream is a sum of base time, logical time and the waiting time. At this time, for the purpose of optimally adjusting the waiting time, this mechanism uses the rate of updating the waiting time and the sampling unit of media. These values are acquired by analyzing the waiting times, the delay rates and the delayed arrival times.

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Power Charge Scheduling and Charge-Ready Battery Allocation Algorithms for Real-Time Drones Services (실시간 드론 서비스를 위한 전원 충전 스케쥴링과 충전 배터리 할당 알고리즘)

  • Tajrian, Mehedi;Kim, Jai-Hoon
    • KIPS Transactions on Computer and Communication Systems
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    • v.8 no.12
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    • pp.277-286
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    • 2019
  • The Unmanned Aerial Vehicle (UAV) is one of the most precious inventions of Internet of things (IOT). UAV faces the necessity to charge battery or replace battery from the charging stations during or between services. We propose scheduling algorithms for drone power charging (SADPC). The basic idea of algorithm is considering both a deadline (for increasing deadline miss ratio) and a charging time (for decreasing waiting time) to decide priority on charging station among drones. Our simulation results show that our power charging algorithm for drones are efficient in terms of the deadline miss ratio as well as the waiting time in general in compare to other conventional algorithms (EDF or SJF). Also, we can choose proper algorithms for battery charge scheduling and charge ready battery allocation according to system parameters and user requirements based on our simulation.

Characteristics of Air Quality in Seoul in Hot Season (서울지역 하절기의 대기질 특성 분석)

  • 정일록;한진석;홍유덕;김정수;조창래;마창민;이길철
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • pp.233-234
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    • 2001
  • 1997년부터 2000년 사이의 하절기(5~9월)의 평일(월~토요일)과 일요일(공휴일 포함)의 매 시간평균 미세먼지 및 오존의 농도특성을 분석하기 위하여 질소산화물(NOx), 오존(O$_3$), 미세먼지(PM10)등의 대기 오염물질을 한 시간단위로 자동측정하는 서울의 27개 측정소의 측정자료를 분석하였다. (중략)

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