• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.173-182
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• 2007

An innovative feature of this study is to propose a methodology for evaluating safety performance in real time based on vehicle trajectory data extracted from video images. The essence of evaluating safety performance is to capture unsafe car-following events between individual vehicles traveling surveillance area. The proposed methodology applied two indices including real-time safety index (RSI) based on the concept of safe stopping distance and time-to-collision (TTC) to the evaluation of safety performance. It is believed that outcomes would be greatly utilized in developing a new generation of video images processing (VIP) based traffic detection systems capable of producing safety performance measurements. Relevant technical challenges for such detection systems are also discussed.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.74-74
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• 2017

• Journal of Korean Society of Transportation
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• v.17 no.3
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• pp.117-130
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• 1999

Earthquakes damage roadway bridges and structures, resulting in significant impacts on transportation system Performance and regional economy. Seismic risk analysis (SRA) procedures establish retrofit priorities for vulnerable highway bridges. SRA procedures use average daily traffic volumes to determine the relative importance of a bridge. This research develops a cost-effective transportation network analysis (TAN) procedure for evaluating numerous traffic flow analyses in terms of the additional system cost due to failure. An important feature of the TNA Procedure is the use of an associative memory (AM) approach in the artificial intelligence held. A simple seven-zone network is developed and used to evaluate the TNA procedure. A subset of link failure system states is randomly selected to simulate synthetic post-earthquake network flows. The performance of different AM model is evaluated. Results from numerous link-failure scenarios demonstrate the applicability of the AM models to traffic flow estimation.

• Korean Journal of Culture and Social Issue
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• v.15 no.3
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• pp.431-446
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• 2009

This study was intended to validate and develop the driving stress coping behavior scale. In a preliminary investigation, literature studies on the driving stress and open questionnaire were administered and examined in four regions in Korea. As a result, 64 items driving stress questionnaire were developed. In the study, this Driving Stress Coping Behavior Scale(DS-CBS) was examined to 372 drivers located seven regions in Korea. The factors analysis revealed 2 meaningful factors[(Good Coping: GC), (Bad Coping: BC) with 24 items. When internal consistency for each 2 factor was calculated, all sub-scale revealed a satisfactory level of Cronbach's α. Also, correlations with Driver Coping Questionnaire(DCQ) and risk driving behaviors(speed driving, drunken driving, traffic violation, offence accident, defence accident) supported consistently validity of the Driving Stress Coping Behavior Scale(DS-CBS). Also, We investigated the influences of 'Good Coping', 'Bad Coping' consisting of driving stress coping behavior, on traffic accidents risk. As a result, 'Good Coping' and 'Bad Coping' influenced traffic accidents risk. 'Good Coping' had decreased effects, the other side 'Bad Coping' had increased effects on traffic accidents risk(TARI).

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2D
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• pp.111-119
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• 2012

In this study, the effect of safety improvement project was analyzed, and a decision making model for traffic accident reduction measures was suggested. The results of this study are as follow; First the overall number of traffic accidents and casualties were reduced, especially reduced the number of unauthorized crossing and centerline encroachments was remarkable. Second, the priorities of traffic accident reduction measures. through hazards roadway section improvement projects were determined. As, higher level evaluation items of AHP hierachy structure include civil facilities and transportation facilities. The civil facilities has 6 lower level evaluation items and transportation facilities has 4 items. The results of this study, It was revealed that traffic experts prefer civil facilities more than transportation facilities and the top 2 items of the each data (or index) took over 50%. In addition, one of the last evaluation contents through the verification, the top 3 items of civil facilities took 55.38%. The project according to the improvement projects for hazards roadway reduced traffic accidents and casualties as well as saving the cost. So these results should be available for basic information for the countermeasure about reducing the traffic accidents by local governments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.145-146
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• 2022

물동량 증가로 인하여 부산신항에는 극초대형 컨테이너 선박들이 입항하고 있으며 서컨테이너 부두 건설 사업이 완료되면 부산신항 진출입 항로 내 다양한 조우 상황 발생으로 충돌 위험 상황을 초래할 수 있어 선박 통항 안전성 향상 방안 마련을 위하여 부산신항 내 항만 입출항 현황과 해상교통흐름을 살펴보았으며, AHP 기법을 활용하여 위험요소 및 안전대책 식별로 도출된 안전대책을 기반으로 환경 스트레스 모델을 활용하여 해상교통류 시뮬레이션을 실시하여 각 안전대책의 교통 위험도를 파악하였다. 설문조사 및 시나리오 평가 결과, 선박운항자는 일방통행을 위한 진입금지 해역 설정을 가장 중요하게 생각하였으며, 이는 위험도 경감에 큰 효과가 있을 것으로 예상되었다, 본 연구는 부산신항을 입출항 하는 선박들의 통항 안전성 제고를 위한 안전대책 마련의 기반이 될 수 있을 것이다.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.133-144
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• 2004

A model and a measure which can evaluate the risk of rear end collision are developed. Most traffic accidents involve multiple causes such as the human factor, the vehicle factor, and the highway element at any given time. Thus, these factors should be considered in analyzing the risk of an accident and in developing safety models. Although most risky situations and accidents on the roads result from the poor response of a driver to various stimuli, many researchers have modeled the risk or accident by analyzing only the stimuli without considering the response of a driver. Hence, the reliabilities of those models turned out to be low. Thus in developing the model behaviors of a driver, such as reaction time and deceleration rate, are considered. In the past, most studies tried to analyze the relationships between a risk and an accident directly but they, due to the difficulty of finding out the directional relationships between these factors, developed a model by considering these factors, developed a model by considering indirect factors such as volume, speed, etc. However, if the relationships between risk and accidents are looked into in detail, it can be seen that they are linked by the behaviors of a driver, and depending on drivers the risk as it is on the road-vehicle system may be ignored or call drivers' attention. Therefore, an accident depends on how a driver handles risk, so that the more related risk to and accident occurrence is not the risk itself but the risk responded by a driver. Thus, in this study, the behaviors of a driver are considered in the model and to reflect these behaviors three concepts related to accidents are introduced. And safe stopping distance and accident occurrence probability were used for better understanding and for more reliable modeling of the risk. The index which can represent the risk is also developed based on measures used in evaluating noise level, and for the risk comparison between various situations, the equivalent risk level, considering the intensity and duration time, is developed by means of the weighted average. Validation is performed with field surveys on the expressway of Seoul, and the test vehicle was made to collect the traffic flow data, such as deceleration rate, speed and spacing. Based on this data, the risk by section, lane and traffic flow conditions are evaluated and compared with the accident data and traffic conditions. The evaluated risk level corresponds closely to the patterns of actual traffic conditions and counts of accident. The model and the method developed in this study can be applied to various fields, such as safety test of traffic flow, establishment of operation & management strategy for reliable traffic flow, and the safety test for the control algorithm in the advanced safety vehicles and many others.

• KDI Journal of Economic Policy
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• v.35 no.4
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• pp.31-61
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• 2013

The purpose of this study is to calculate the economic value of transport demand forecasting risks in the road PPP project. Under the assumption that volatility of the road PPP project value occurs only in regard with uncertainty of traffic volume forecasting, this study calculates the economic value of the traffic forecasting risks in the case of the road PPP project. To that end, forecasted traffic volume is assumed to be a stochastic variable and to follow the Geometric Brownian motion as time passes. In particular, this study attempts to differentiate itself from existing studies that simply use an arbitrary assumption by presenting the application of different traffic volume growth volatility and the rates before and after the ramp-up period. Analysis of the case projects reveals that the risk premium related to traffic volume forecast of the project turns out as 7.39~8.30%, without considering option value-such as minimum revenue guarantee-while the project value volatility caused by transport demand forecasting risks is 17.11%. As the discount rate grows higher, the project value volatility tends to decrease and volatility in project value is always suggested to be larger than that in transport volume influenced by leverage effect due to fixed expenditure. The market value of transport demand forecasting risk-calculated using the project value volatility and risk premium-is analyzed to be between 0.42~0.50, implying that a 1% increase or decrease in the transport amount volatility would lead to a 0.42~0.50% increase or decrease in risk premium of the project.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.157-159
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• 2012

해상 교통량 증가에 따른 연안해역 해상교통밀집도가 증가되고 있다. 그러므로 해상교통안전관리를 위해 실 해역의 해상교통패턴을 파악하여 해상교통지수를 평가하는 것이 중요하다. 분석대상해역의 실제 선박위치, 속력, 침로를 고려한 CPA-TCPA분석은 통계적인 선박데이터에 의한 분석보다 해당해역의 실제적인 VTS영향 등 교통환경을 반영한다. 본 연구에서는 횡간수도와 완도진입수로의 항로가동률을 분석하고, 해당 해역에서 교차되는 선박들의 CPA, TCPA 등을 분석하여 해상교통안전지수를 평가하고자 한다. 또한 산출된 해상교통안전지수를 해당 해역의 통계적인 해상교통안전지수와 비교 및 분석하고자 한다.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.4
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• pp.723-728
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• 2022

This study is a method for evaluating and quantifying driver's dangerous driving behavior. The quantification method calculates various driving information in real time after starting the vehicle operation such as the time that the vehicle has been continuously driven without a break, overspeed, rapid acceleration, and overspeed driving time. These quantified risk of driving behavior values can be individually provided as a safe driving index, or can be used to objectify the evaluation of a group of drivers on roads, or vehicle groups such as cargo/bus/passenger vehicles.