• 방송공학회논문지
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• 제8권1호
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• pp.45-53
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• 2003

Traffic specification plays a crucial role in the resource reservation for video services over the packet-switching networks. The current development of QoS-guaranteed service still leaves a wide space for the selection of traffic specification. We propose a new method to estimate the traffic specification of variable-bit-rate (VBR) video for deterministic service. The method is based on the concept of empirical envelope and the delay bound. The solution shows to be simple yet it provides excellent network utilization.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2002년도 정기총회 및 학술대회
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• pp.85-90
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• 2002

Traffic specification plays a crucial role in the resource reservation for video services over the packet-switching networks. The current development of QoS-guaranteed service still leaves a wide space for the selection of traffic specification. We propose a new method to estimate the traffic specification of variable-bit-rate (VBR) video for deterministic service. The method is based on the concept of empirical envelope and the delay bound. The solution shows to be simple yet it provides excellent network utilization.

• 대한교통학회지
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• 제5권2호
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• pp.19-35
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• 1987

Transportation energy saving is a national concern because all national petroleum energy is imported. A number of intersections are operating as semi-protected intersections, which have left-turn signal but not exclusive left-turn lanes, because of limited roadways in urban areas. Since the traffic signal methods for the intersections having left-turn signal/lanes cannot be applied to the semi-protected intersection, it is needed to develop a new technique. The purpose of this study was to develop a traffic signal timing method at semi-protected intersections for energy saving and to computerize the method for the practical use. A probability model which could estimate left-turn utilization factors of through traffic during green signal was developed based on field studies. Employing the factors, macro-models to estimate vehicular average delay and proportions of vehicles stopped at the semiprotected intersections were developed. The calculated values of the delay model agreed well with the simulated values of a simulation model using SLAM Ⅱ, a simulation language. Using the two models and the idling fuel consumption rate and the excess fuel consumption per stop-go speed change of vehicles. a traffic signal timing method at semi-protected intersections for energy saving was developed and computerized. The method can be used for other measures of effectiveness such as minimum delay, minimum stop ratio, etc.

• 대한교통학회지
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• 제35권1호
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• pp.25-36
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• 2017

본 연구는 이륜자동차의 안전검사제도가 도입될 경우 교통사고 절감효과에 관한 분석을 다루고 있다. 이를 위하여 우선, 독일 차량 및 운전자 연방국의 차령별 결함률을 이용하여 국내 차령별 이륜자동차 결함대수를 추정하고, 도로교통공단의 4년간 차량결함에 따른 사고건수 자료를 바탕으로 차량결함으로 인한 교통사고 확률을 산정한 뒤, 검사제도로 인한 차량결함 제거비율을 적용하여 검사제도 도입으로 인한 교통사고 감소건수 및 감소된 교통사고비용을 추정하였다. 배기량별 제도도입을 가정하여 시나리오를 구분하여 분석하였는데, 전체 이륜자동차를 대상으로 안전검사제도를 도입 할 경우 교통사고 642건/연 및 교통사고비용 325억 원/연이 감소되는 것으로 분석되었다. 이는 2014년 국내교통사고비용 26조 5,725억 원/연의 약 0.1%에 해당되는 수준으로 이륜자동차 안전검사제도 도입 시 차량적 요인으로 인한 교통사고 및 교통사고비용이 감소되는 기대효과를 제시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권6호
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• pp.2964-2985
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• 2019

Global data center IP traffic is expected to reach 20.6 zettabytes (ZB) by the end of 2021. Intra-data center networks (Intra-DCN) will account for 71.5% of the data center traffic flow and will be the largest portion of the traffic. The understanding of traffic distribution in IntraDCN is still sketchy. It causes significant amount of bandwidth to go unutilized, and creates avoidable choke points. Conventional transport protocols such as Optical Packet Switching (OPS) and Optical Burst Switching (OBS) allow a one-sided view of the traffic flow in the network. This therefore causes disjointed and uncoordinated decision-making at each node. For effective resource planning, there is the need to consider joining the distributed with centralized management which anticipates the system's needs and regulates the entire network. Methods derived from Kalman filters have proved effective in planning road networks. Considering the network available bandwidth as data transport highways, we propose an intelligent enhanced SDN concept applied to OBS architecture. A management plane (MP) is added to conventional control (CP) and data planes (DP). The MP assembles the traffic spatio-temporal parameters from ingress nodes, uses Kalman filtering prediction-based algorithm to estimate traffic demand. Prior to packets arrival at edges nodes, it regularly forwards updates of resources allocation to CPs. Simulations were done on a hybrid scheme (1+1) and on the centralized OBS. The results demonstrated that the proposition decreases the packet loss ratio. It also improves network latency and throughput-up to 84 and 51%, respectively, versus the traditional scheme.

• 한국항만경제학회지
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• 제21권4호
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• pp.255-274
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• 2005

To acquire a port traffic, governments in North-East Asia have intensively invested port development. Furthermore, the major shipping company directly make a call at northern chinese ports like Qingdao, Dalian and Tianjin. Those changes of port environment will have a considerable effect on a port traffic in Korea. In order to prepare against those changes, it is necessary to estimate a port traffic in Korea A port traffic in Korea is estimated by the use of explanation variables like GDP of Korea, real effective exchange rate, world economic performances and the trade in China, et al. When GDP in Korea goes up 1%, it is estimated that container port traffic of all ports and Pusan Port is upward $1.0{\sim}1.2%$ and $0.8{\sim}0.9%$ respectively. When the trade in China goes up 1%, it is estimated that Container transshipment is upward $1.6{\sim}1.7%$ approximately.

• 대한토목학회논문집
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• 제30권3D호
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• pp.241-246
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• 2010

본 연구는 버스정보시스템(BIS)의 운영을 통해 수집되고 있는 데이터를 이용하여 도시내 가로의 통행시간을 추정하기 위한 연구이다. 기존의 버스시스템에 첨단정보통신 기술을 접목한 BIS는 많은 지방자치단체에서 구축하여 운영 중에 있다. 그러나 이러한 기술동향을 반영한 연구는 부족한 실정이다. 기존에 구축된 BIS의 운영을 통해 유용한 교통정보들이 수집되고 있으나 수집된 데이터의 활용은 활발히 이루어지지 못하고 있다. 본 연구에서는 BIS의 운영을 통해 수집되고 있는 버스운행 데이터를 이용하여 도시내 가로의 링크통행시간 추정을 통해 도시의 교통관리에 활용하고 운전자에게 교통정보를 제공하기 위한 기초적인 연구를 수행하고자 하였다. 연구결과 버스의 링크통행시간이 두 개의 군집으로 나타났으며 따라서 링크통행시간을 두 개의 군집으로 나누어 추정모형을 구축하였다. 구축된 모형을 통계적으로 검정하기 위해 T-test를 실시한 결과 통계적으로 유의한 것으로 분석되었다.

• 한국ITS학회 논문지
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• 제12권3호
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• pp.42-52
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• 2013

본 연구는 비시장재화의 가치추정을 위해 환경경제학 분야에서 발전되어 온 가치추정방법인 조건부가치측정법을 교통 분야에 적용하여 VMS 교통정보의 가치를 산정하였다. 조건부가치측정법(CVM)은 사업 시행 전 이용자들이 대상재에 대해 부여하는 가치를 추정하고, 추정된 값을 근거로 사업의 타당성을 간접적으로 검토할 수 있는 방법이다. 본 연구에서는 고속도로의 교통문제를 완화시키기 위한 방안으로 도로공사에서 추진 중인 교통체계 선진화 사업 중 가변전광판(VMS)에서 제공하는 교통정보의 가치를 추정하였다. 특히 본 연구는 기존연구와는 다르게 통행목적, 정보의 종류, 소통 상태에 따른 정보의 가치를 분석하였다. 비시장재인 교통정보의 가치를 추정하기 위해 가상시나리오를 설계하여 진술선호 방법을 활용하여 설문하였으며, 설문의 신뢰도를 높이기 위해 설문에 앞서 예비조사를 실시하였다. 지불용의액의 설문방식은 직접설문법을 채택하였다. 교통정보의 가치추정의 방법으로 Tobit 모형과 이항 probit 모형을 이용하였고 계수 추정은 최우추정법을 이용하여 계수를 추정하였다. 연구결과 고속도로 이용자들이 생각하고 있는 교통정보의 가치는 건당 518.28원으로 추정되었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1989년도 가을 학술발표회 논문집
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• pp.59-64
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• 1989

On this condition of steel bridge member having a crack, occasionaly it is improssible to measure of stress history and to extract test specimen. Under this situation, tried to estimate remaining service life from statistical data on traffic and existing results of fatigue test without measuring of stress history and fatigue test. The main results are as following (1) Stress history of simple beam estimated from Montecallo simulation method with probabilistic model of traffic can be use to estimate remaining fatigue life instead of measuring of stress history. (2) In such a case measuring of remaining fatigue life at bridge member haying a crack, influences of RMS model and RMC model on fatigue crack growth rate are not differ without difference of applied stress range. (3) Application of cut off method may be overestimate remaining fatigue life.

• 국토계획
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• 제53권6호
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• pp.117-130
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• 2018

Heavy snow is a natural disaster that causes serious economic damage. Since snowfall has been increasing recently, there is a need for measures against heavy snowfall. In order to make a policy decision on heavy snowfall, it is necessary to estimate the precise amount of damage by heavy snowfall. The direct damage of the heavy snow is severe, however the indirect damage caused by the road congestion and the urban dysfunction is also serious. Therefore, it is necessary to estimate indirect damage of snowfall. The purpose of this study is to estimate the effects on the regional economy from the limitation in traffic logistics caused by heavy snow using the transport demand model and inoperability input-output Model. The result shows that the amount of production loss caused by the heavy snow is KRW 2,460 billion per year and if the period of snowfall removal is shortened by one day or two days, it could be reduced to KRW 1,219 or 2,787 billion in production loss.