• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.33-35
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• 2023

자율운항선박의 항로계획정보와 주변선박의 항적 데이터를 기반으로 자율운항선박 주변의 위험선박을 자동으로 추출하고, 충돌위험지수를 산출하여, 위험지수에 따른 안전지원항로를 생성하여 자율운항선박에 제공하는 자율운항지원서비스 운영 소프트웨어 개발에 관한 연구이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.181-182
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• 2021

본 연구에서는 자율운항선박의 원격 관제 및 제어하는 과정에서 원격 운항자에게 사전 충돌 위험 정보를 제공하기 위해 선박자동식별시스템(AIS, Automatic Identification System)의 항적 정보를 토대로 자율운항선박의 운항 경로 상에 잠재된 충돌 위험 영역을 예측하기 위한 기초 연구를 수행하였다. 자율운항선박의 운항 경로 상에 근접한 타선의 AIS 정보에는 기본적으로 선박의 위치, 속도, 침로에 대한 정보가 반영되어 있으므로, 이러한 정보를 토대로 일정 시간 동안 운항 경로를 예측할 수 있다. 그리고 예측한 정보를 기반으로 대표적 충돌 위험 지수인 최근접점(CPA, Closest Point of Approach)과 최근접점 거리(DCPA, Distance to CPA) 정보를 활용하여 충돌 위험 영역을 2차원 공간상에서 예측하였다. 제안된 방법은 실제 AIS 항적 데이터를 활용한 수치 시뮬레이션을 수행하여 초기 결과를 검증하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.483-491
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• 2021

The identification of regional collision risks in water areas is significant for the safety of navigation. This paper introduces a new method of collision risk assessment that incorporates a clustering method based on the distance factor - hierarchical clustering - and uses real-time data in case of several surrounding vessels, group methodology and preliminary assessment to classify vessels and evaluate the basis of collision risk evaluation (called HCAAP processing). The vessels are clustered using the hierarchical program to obtain clusters of encounter vessels and are combined with the preliminary assessment to filter relatively safe vessels. Subsequently, the distance at the closest point of approach (DCPA) and time to the closest point of approach (TCPA) between encounter vessels within each cluster are calculated to obtain the relation and comparison with the collision risk index (CRI). The mathematical relationship of CRI for each cluster of encounter vessels with DCPA and TCPA is constructed using a negative exponential function. Operators can easily evaluate the safety of all vessels navigating in the defined area using the calculated CRI. Therefore, this framework can improve the safety and security of vessel traffic transportation and reduce the loss of life and property. To illustrate the effectiveness of the framework proposed, an experimental case study was conducted within the coastal waters of Mokpo, Korea. The results demonstrated that the framework was effective and efficient in detecting and ranking collision risk indexes between encounter vessels within each cluster, which allowed an automatic risk prioritization of encounter vessels for further investigation by operators.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.12
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• pp.1503-1510
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• 2012

This paper presents an Integrated Risk Management System (IRMS), which is designed to integrate longitudinal and lateral collision avoidance systems. Indices representing longitudinal and lateral collision risks are designed. From the designed indices, an integrated control strategy is designed. A collision avoidance algorithm is designed to assist the driver in avoiding collisions by using a vehicle-driver-controller integrated linear model. The performance of the proposed algorithm is investigated via computer simulations conducted using the vehicle dynamics software CARSIM and Matlab/Simulink.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.175-186
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• 2010

When a rigid post is exposed to traffic, it is hazardous not only to head-on impacts but also to side impacts. Clip-type slip base is an effective measure to reduce the severity of head-on impacts and side impacts as well because of its multi-directional release mechanism. Side impact tests were conducted and the results were analysed to demonstrate the hazardousness of a rigid post to a side impact and the crash worthiness of a post having clip-type slip base. For that, side impact test standard was made adapting the NCHRP Report 350, and 820kg-50km/h side impact tests were made for posts of D101.6mm(t=4.2mm) with and without slip base. Additionally, 35km/h side impact to the same post with slip base was conducted to check whether the clip-type slip base release mechanism works properly to the low impact speed. The tests revealed that the rigidly connected post was very hazardous to side impact while the post with the clip-type slip base reduced the impact severity tremendously.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.93-102
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• 2017

When VTSOs (Vessel Traffic Service Operator) determine the degree of collision risk for two vessels, they consider comprehensive information about each vessel's course, speed, DCPA, TCPA, and encountering situation. In this study, we proposed a utility function based on the risk attitudes of VTSOs toward the Risk Index (RI). The RI was calculated using the risk of encounter, the risk of approach, and the risk of time for two vessels in order to predict each ship's collision risk from the VTS viewpoint. We obtained each coefficient of the RI and the risk attitude through a survey of collision risks among VTSOs of Korea. In order to verify whether the proposed utility is reasonable, we validated by applying the degree of collision risk to some historical cases of accidents in Busan port along with the Ship of ES value($ES_S$) of ES(Environmental Stress) model.

• Journal of Navigation and Port Research
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• v.43 no.4
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• pp.250-255
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• 2019

The objective of this study was to analyze the risk of collision accidents to the VTSOs (Vessel Traffic Service Operators) as small ferries and fishing boats are expanded for monitoring targets. The VTSOs was surveyed, the scale of the small vessels defined and the course of general cargo vessels and small vessels along the Busan VTS area investigated for three days. From calculating the risk with CoRI, patterns of increased or decreased risk due to course deviation were similar, and there was no significant difference between the maximum values and the minimum values. In addition, most VTSOs responded that the minimum time required was approximately three minutes to safely instruct in encounter situation, however, the collision risk with a small vessel is very rapidly changing within the three minutes, which is likely to increase the workload and decrease the concentration of the VTSOs. The objective of this study was to investigate the effect on VTSOs with respect to the expansion of small vessels as collision risk, it is expected that it will contribute to the establishment of a suitable scale for the target vessels for VTS through the analysis of each index of the CoRI model and various case studies.

• Journal of Auto-vehicle Safety Association
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• v.5 no.1
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• pp.44-49
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• 2013

This paper presents a lateral collision risk index between an ego vehicle and a rear-side vehicle. The lateral collision risk is designed to represent a lateral collision risk and provide the appropriate threshold value of activation of the lateral collision management system such as the Blind Spot Detection(BSD). The lateral collision risk index is designed using the Time to Line Crossing(TLC) and the longitudinal collision index at the predicted TLC. TLC and the longitudinal collision index are calculated with the signals from the exterior sensor such as the radar equipped on the rear-side of a vehicle and a vision sensor which detects the distance and time to the lane departure. For the robust situation assessment, the perception of driving environment determining whether the road is straighten or curved should be determined. The relative motion estimation method has been proposed with the road information via the integrated estimator using the environment sensors and vehicle sensor. A lateral collision risk index was composed with the estimated relative motion considering the relative yaw angle. The performance of the proposed lateral collision risk index is investigated via computer simulations conducted using the vehicle dynamics software CARSIM and Matlab/Simulink.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.197-202
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• 2010

Post release mechanism is generally used to reduce the severity of the occupant of an errant vehicle impacting a roadside posts. The 820kg-50km/h head-on impact simulations were made using LS-DYNA program for the posts of 101.6mm Dia(t=4.0mm) with and without clip-type release mechanism. The simulation result was compared with impact test result to enhance the credibility of simulation model. The study shows that the high impact severity (THIV, PHD) and excessive deformation threatens the safety of the occupant when a car impacts a rigidly connected posts, while a post with clip-type slip base reduce the impact severity to a safe level.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.225-227
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• 2023

선박의 안전운행을 지원하기 위해 다양한 정보를 신속하고 정확하게 파악할 필요가 있다. 이를 지원하기 위해 6종 개별 서비스를 표출하고, 별도의 데이터를 통합해서 표시하는 통합대시보드를 배치하여 종합적인 정보를 한눈에 확인할 수 있도록 하였다. 통합대시보드는 선박의 안전상태(충돌위험지수, 횡경사, 침수상태 등)를 시각적으로 확인이 용이하게 디자인 되었으며, 사고 발생 시 상태모니터링을 통해 신속한 의사결정이 가능하도록 구성하였다.