• Journal of Korean Society of Transportation
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• v.36 no.1
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• pp.38-50
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• 2018

Emerging automated driving environments will lead to a mixed traffic flow depending on the interaction between automated vehicles (AVs) and manually driven vehicles (MVs) because the market penetration rate (MPR) of AVs will gradually increase over time. Understanding the characteristics of mixed traffic conditions, and developing a method to control both AV and MV maneuverings smoothly is a backbone of the traffic management in the era of automated driving. To facilitate smooth vehicle interactions, the maneuvering of AVs should be properly determined by various traffic and road conditions, which motivates this study. This study investigated whether the aggressiveness of AV maneuvering, defined as automated driving aggressiveness (ADA), affect the performance of mixed traffic flow. VISSIM microscopic simulation experiments were conducted to derive proper ADAs for satisfying both the traffic safety and the operational efficiency. Traffic conflict rates and average travel speeds were used as indicators for the performance of safety and operations. While conducting simulations, level of service(LOS) and market penetration rate(MPR) of AVs were also taken into considerations. Results implies that an effective guideline to manage the ADA under various traffic and road conditions needs to be developed from the perspective of traffic operations to optimize traffic performances.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.6
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• pp.1-14
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• 2011

The surrogate safety assessment model which was developed based on the conflict theory by FHWA in the US is software to analyze traffic conflicts using the individual vehicle trajectory data from a microscopic traffic simulation model. This study aims at assessing the safety of different signal control strategies, including pre-time and actuated signal control, using the SSAM. To this end, this study effort has developed a microscopic traffic simulation model using VISSIM through a field study, and then produced the surrogate measures, including TTC, PET, DR, MaxS and DeltaS, and the numbers of conflicts, including rear-end, right angle and lane-changing conflicts. The assessment results indicated that the actuated signal control may produce more conflicts in terms of rear-end conflicts. The use of SSAM in the safety assessments for diverse traffic alternatives in a safe and fast way may contribute to the improvement of safety in the roadway transportation.

• Journal of Korean Society of Transportation
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• v.28 no.4
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• pp.7-18
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• 2010

This study analyzed the relative vehicle speed and vehicle deceleration time caused by traffic conflicts using vehicle speed data at expressway toll gates and traffic conflict occurrence data. According to the analysis, the greater the relative vehicle speed is at the toll gate, the more sudden vehicle deceleration occurs due to traffic conflicts. In particular, a comparison study of cases in similar operating conditions presents a finding that usage of lanes influences traffic conflict occurrences as well as relative vehicle speed. With this finding, the study further conducted a quantitative analysis of the accident rates in relation to the relative vehicle speed between vehicles using a "Hi-Pass" lane and a regular lane at the toll gate. It indicates that when the relative vehicle speed is greater, the accident rate is higher due to sudden vehicle deceleration and shorter deceleration time. Furthermore, when the expressway entrance/exit point is closely located to a toll gate and the relative vehicle speed is great, a analysis at a traffic conflict shows a low value.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.2 s.10
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• pp.61-71
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• 2006

The main purpose of this study is to search a method for reducing traffic accident at signalized intersections. One of the important factors for this is the Left-turn phase sequence. In 1985, the operational principle of Left-turn phase Sequence was changed from Lagging left-turn to Leading left-turn in Korea. Then there was a resonable motive-no exclusive left turn-lane and narrow intersection. So, it is necessary to evaluate the performance difference between Leading and Lagging left -turn phase Sequence. The process of this study is as follows: $\cdot$ First, all the intersection was divided three parts for analysis the traffic safety: Inside part of an Intersection, Crosswalk, Intersection approach and exit. $\cdot$ Second, a safety analysis was performed by using the concepts of 'Effective interphase Period(EIP)' and 'Conflict method' The Study result is that the benefit of of phase Sequence changes from Leading to Lagging phase were significant. For an example the Accident cost will reduced about 41.8 billion won per year in korea.

• Journal of Arbitration Studies
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• v.24 no.2
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• pp.81-107
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• 2014

ADR has recently been expanded, making it possible to solve traffic accident disputes, which is a matter of urgency for parties to avoid. This point serves as an important procedural element. Such disputes are an area that requires a quick resolution. To try to solve any dispute that occurs in the complex environment of modern times one-by-one through litigation does not make sense. It gives an undue burden on the judicial body and the investigation agency. Like litigation, today's arbitration system, should have effective conflict resolution. The arbitration of automobile traffic accident disputes can be seen as roughly adjusted through the insurance company, the Dispute Coordinating Committee, and the Crime Victims Protection Act. It consists of experts mainly, and the resolution of automobile traffic accident disputes can be resolved through the Sajonsa and workers insurance company. However, adjustments to failure incident mostly need attention. Most of a company's compensation insurance indemnity needs to be processed in practice. In addition, a vicious cycle of litigation and delay period is repeated if a lawyer is appointed. There are unreasonable adjustment systems in the midst of these. Avoiding traffic accidents allows parties to resolve disputes better. Arbitration of disputes in automobile traffic accidents handled by arbitration institutions is desirable. It is determined that the handling of a case by a village attorney is efficient.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.179-185
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• 2007

In large station with high density traffic, trains can be hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within each station such as departures, arrivals of many trains from different lines and shunting of trains to move between yards and platforms, etc. Therefore the station's dispatcher has to make quick decision about how to reschedule the times and routes for all the trains scheduled within a specific time window. And such decision becomes harder when an unexpected delay occurs because a delay occurring in a train propagates other trains as time goes on. Generally, it is called the conflict detection and resolution to adjust beforehand the distorted schedule due to a delay to original schedule. Our research is different from the state of the arts in that ours determines simultaneously the routes and the times of arrival and departure of trains, although others do only the arrival and departure time of the trains without considering the alternative routes and shunting of the station. This study suggests a mathematical approach for how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.413-418
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• 2015

As the elderly are increasing, traffic accidents which are related to the elderly are one of major issues in aged society. In this paper, we analyze traffic accident statistics for the elderly. Based on the analyzed data, safety message transmission system for the elderly pedestrians is introduced. The proposed system is based on the P2V(Pedestrian-to-Vehicle) communication which combines ICT(Information and Communication Technology) with vehicles and pedestrians. We introduce the concept and principle of the proposed system and discuss implementation issues for realizing the proposed system.

• Journal of Korean Port Research
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• v.14 no.3
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• pp.269-278
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• 2000

Today the pedestrian-related problems a key subject requiring the attention of the traffic engineers for improving the transportation system. Particularly in urban and CBD locations, the pedestrian presents an element of sharp conflict with vehicular traffic. Therefore pedestrian movements must be studied for the purpose of providing guideline for the design and operation of walking transportation systems. This paper is to address the characteristics of walking transportation in a big city. Especially the focuses are emphasized on the ratio occupied by pedestrian traffic among the whole unlinked trips in a city and walking time. The data for analysis are collected in Seoul metropolitan city through sampling 1,006 citizens. Compared with other similar research works this paper utilized diversified tools to acquire more useful results. Finally, policy directions for pedestrian environment improvement were suggested.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2000.11a
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• pp.53.2-60
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• 2000

One of the elements requiring the attention of the traffic engineer is the pedestrian. Particularly in urban and CBD locations ,the pedestrian presents an element of sharp conflict with vehicular traffic. Therefore pedestrian movements must be studied for the purpose of providing guideline for the design and operation of transportation systems. This paper addressed the characteristics of walking transportation in a big city. Especially the focuses are emphasized on the ratio occupied by pedestrian traffic among the whole unlinked trips in a city and walking time. The data for analysis are gathered in Seoul metropolitan city sampling 1,006 citizens. Compared with other similar research works this paper utilized diversified tools to acquire more useful results.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.1159-1164
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• 2005

현재 철도청이 운용중인 열차운행관리 시스템(Railway Traffic Management System, RTMS)은 서울, 대전, 부산, 순천 그리고 영주 등으로 총 5개 지역본부로 분산되어 있어 업무의 중복을 줄이고, 자동화(Automation)된 열차집중제어장치(Central Traffic Control, CTC)를 구축하기 위해 지역본부를 대전으로 통합하는 프로젝트를 진행중이다. 본 논문은 철도청 사령실 통합 신호설비 구축 프로젝트에 의거하여 열차 경합을 검지 또는 예측하고 운영자에게 최소의 시간 내에 최적의 해소 대책을 제시함을 목적으로 하는 열차 경합 검지 시스템을 구현하는 과정에서 작성되었다. 여기에서는 열차 경합 검지에 대한 개요와 검지 가능한 경합 종류에 대해 기술하고, 실제 구현된 알고리즘의 기본적인 내용, 프로세스의 구성도 및 시뮬레이션 결과를 설명하려고 한다.