• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.447-454
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• 2017

Using two large coast guard ships at sea, we created four encounter situations ($000^{\circ}$, $045^{\circ}$, $090^{\circ}$, $135^{\circ}$) with high possibility of collision, from 3 NM up to 0.25 NM. As relative distance was gradually decreased, the subjects were measured at 0.25 NM intervals and perceived ship collision risk (PSCR) was determined by looking at the opponent ship. Characteristics were statistically analyzed using the obtained data. The purpose of this study was to analyze the characteristics of collision risk values obtained from twelve intervals, from 3 NM to 0.25 NM relative to encounter situations by curve fitting with appropriate polynomials, to determine the distance from which the change in perceived collision risk is greatest. As a result, an optimal regression equation for each distance interval was derived from each analysis direction. The greatest variation in average collision risk value was over the range 1.25 ~ 1 NM, and the collision risk value was largest at 1 NM. The maximum change in perceived collision risk was at 1 NM. These results can contribute to preventive guidelines to minimize human error in close proximity situations with a high probability of ship collision.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.400-401
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• 2015

해상 교통 관제를 함에 있어서 선박간의 충돌 사고를 미연에 방지하기 위해 관제사의 의사 결정을 도울 수 있는 기술들이 많이 개발되고 있다. 관제 시 선박간의 충돌 위험을 판단하고 사고를 미연에 방지하기 위해, 관제사들이 가장 빈번하게 사용되는 기능이 CPA와 거리/방위각 측정기능이다. 하지만, 기존 해상관제 시스템들은 이러한 기능들이 독립적으로 구성되어 있어, 관제사들의 신속한 업무 처리를 방해할 뿐만 아니라, 관제사의 업무 피로도를 종종 증가시킨다. 본 논문에서 제안한 방법은 관제사 설문조사를 통해 수렴된 내용을 토대로 기존의 CPA, 거리/방위각 측정 기능을 보완하여 CPA 계산 시 선박 조우 정보를 제공하고, 관제사로 하여금 충돌예상 선박들에 대해 신속한 초동 조치 지시를 가능하게 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.47-48
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• 2015

VTSO make a decision which one will be danger and what to expect ship's actions due to each encountering situation with CPA(Closest Point of Approach) and TCPA(Time to Closest Point of Approach) by monitoring ship's vectors(Course & Speeds) in real-time through the VTS system. This study is the fundamental research for developing algorithm and system that does not decide the collision risk in one's own ship's viewpoints, but it identifies the related ships into danger through the third party(VTS ) in real time.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.202-204
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• 2015

2010년부터 최근 5년간 해양안전심판원의 충돌사고 통계분석 결과에 따르면 98%가 인적과실이 원인이 될 정도로 경계소홀 등 해기사에 의한 운항과실이 해양사고의 대부분을 차지하고 있으나 그동안 외국뿐만 아니라 국내에서도 이에 대한 연구는 극히 미흡한 실정이다. 본 연구는 항해중인 선박이 타 선박과 6가지 유형(Head-on, $045^{\circ}$, $090^{\circ}$, $135^{\circ}$, Overtaking, Overtaken)의 다른 방위각으로 조우 상황시 양 선박의 거리가 가까워지면서 거리별 항해당직사관인 해기사가 느끼는 스트레스(주관적 위험도)를 실제 항해중인 선박에 승선하여 실험하였고 획득한 데이터를 통계적으로 분석 및 처리하였다. 데이터를 곡선적합(Curve fitting) 적용 결과 6가지 조우각도별 거리에 따른 연속 데이터 획득이 가능 하였고 인적과실의 주요 원인 중의 하나인 타 선박 조우 상황시 해기사가 느끼는 스트레스 일반화 모델을 위한 기초 식을 제안하였다. 이러한 결과는 향후 해기사의 인적과실을 줄여 해양사고 예방을 위한 기초 자료로 활용 할 수 있을 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.125-127
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• 2014

본 논문은 선박의 일대다 충돌상황에서 국제해상충돌예방규칙(COLREGs, International Regulations for Preventing Collisions at Sea, 1972)을 만족하도록 피항경로를 생성하는 충돌회피 알리고즘의 개발과 적용에 관해 기술한다. 본 연구에서 제안하는 알고리즘은 조우선박의 상대 방위각, 충돌위험정도 및 상호시계와 제한시계의 시계상태에 따라 피항동작을 분류하고, 규칙기반형태의 전문가시스템인 CLIPS(C Language Integrated Production System)를 이용하여 국제해상충돌예방규칙에 따른 피항행동공간을 생성한다. 검증을 위하여 Izuma problems의 3가지 충돌상황을 가정한 컴퓨터 시뮬레이션을 수행하였으며, 다양한 충돌상황에 대하여 안전한 충돌회피경로가 생성됨을 확인 할 수 있었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.462-469
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• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.116-118
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• 2023

In recent years, the need for economical and sustainable ship routing has emerged due to the enforced regulations on environmental issues. Despite the development of weather forecasting technology, maritime accidents by rough waves have continued to occur due to incorrect weather forecasts. In this study, onboard measurements are conducted to observe the acutal situation on merchant ships in operation encountering rough waves. The types of measured data include information related to navigation (Ship's position, speed, bearing, rudder angle) and engine (engine revolutions, power, shaft thrust, fuel consumption), weather conditions (wind, waves), and ship motions (roll, pitch, and yaw). These ship experiments was conducted to 28,000 DWT bulk carrier, 63,000 DWT bulk carrier, 20,000 TEU container ship, and 12,000 TEU container ship. The actual ship experiment of each ship is intended to acquire various types of data and utilize them for multi-objective studies related to ship operation. Additionally, in order to confirm the sea conditions, the directional wave spectrum was reproduced using a wave simulation model. Through data collection from ship experiments and wave simulations, various studies could be proceeding such as the measurement for accurate wave information by marine radar and analysis for cargo collapse accidents. In addition, it is expected to be utilized in various themes from the perspective of safety and efficiency in ship operation.