• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.83-83
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• 2018

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.15-22
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• 2009

Auto-navigation algorithm have been studied to avoid collision and grounding of a ship due to human error. There have been many research on collision avoidance algorithms but they have been validated little on the real coastal traffic situation. In this study, a Collision Avoidance algorithm is developed by using Fuzzy algorithm and the concept of Changeable Action Space Searching (CAS). In the first step, on a basis of collision risk calculated from fuzzy algorithm in the current time(t=to), alternative Action Space for collision avoidance is planned. In the second step, next alternative Action Space for collision avoidance in the future($t=to+{\Delta}t$) is corrected and re-planned with re-evaluated collision risk. In the third step, the safest and most effective course among Action Space is selected by using optimization method in real time. In this paper, the main features of the developed collision avoidance algorithm (CAS) are introduced. CAS is implemented in the ship-handling simulator of MOERI. The performance of CAS is tested on the situation of open sea with 3 traffic ships, whose position is assumed to be informed from AIS. Own-ship is fully autonomously navigated by autopilot including the collision avoidance algorithm, CAS. Experimental results show that own-ship can successfully avoid the collision against traffic ships and the calculated courses from CAS are reasonable.

• Journal of Navigation and Port Research
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• v.34 no.6
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• pp.405-415
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• 2010

To assess the possible collision risk between Mokpo Harbour Bridge, which is under construction, and passing vessels, we proposed Real-Time Bridge-Vessel Collision Model (RT-BVCM) in this paper. The mathematical model of RT-BVCM consists of the causation probability by the vessel aberrancy due to navigation environments, the geometric probability by the structural feature of a bridge relative to a ship size and, the failure probability by the ship collision track and the stopping distance which is not to come to a stop before hitting the obstacles. Then, the probabilistic mathematical model represented as risk index with the risk level from 1 to 5. The merit of the proposed model to the collision model proposed by AASHTO (American Association of State Highway and Transportation Officials) is that it can provide enough time to take adequate collision avoiding action. Through the simulation tests to the two kinds of test ships, 3,000 GT and 10,000 GT, it is cleary found that the proposed model can be used as a collision evaluation model to the passing vessel and Mokpo Harbour Bridge.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.29-34
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• 2005

A mis-handling of the ship operators, treated as one qf the main causes of a ship accidents, normally has caused a ship to collide with obstacles like a reef, a rock and other ships etc. since their ability has been declining little by little even though the port conditions have been getting worse. The ship needs a highly sophisticated technology as her size and speed increase as the ship have been demanded. For example, Auto Avoidance Control System gradually has been receiving a growing interest to control the entire ship safely. From that purpose, this research has been done. The research was based on the MMG mathematical model, used Surge-Sway-Yaw-Roll motion equation and Fuzzy theory for calculating the collision-risk Also the research successively was done when the ship encountered continual multitude ships.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.12
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• pp.1700-1709
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• 2019

Recently, many researches have been under way to develop systems (services) to support the safety navigation of ships, and in these studies, common difficulties have been encountered in assessing the usefulness and effectiveness of the developed system. To solve these problems, we propose the DEVS-based ship navigation modeling and simulation technique. Following the preceding study, we analyze the COLREG rules and reflected to officer and helmsman agent models for decision making. Also we propose estimation and interpolation techniques to adopt the motion characteristics of the actual vessel to simulation. In addition, we implement the navigation simulation system to reflect the designed proposed methods, and we present five-scenarios to verify the developed simulation system. And we conduct simulations according to each scenario and the results were reconstructed. The simulation results confirm that the components modelled in each scenario enable to operate according to the navigation relationships.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.311-313
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• 2018

해양안전심판원의 해양사고 통계자료에 따르면 기관손상 등을 제외한 해양사고 중 충돌사고의 비중은 가장 높고, 대부분의 충돌사고는 경계소흘 등 운항과실이 약 90%를 차지한다. 본 연구에서는 운항자의 항행 안전을 지원하고자 육상 무선 통신기술을 이용하여 중소형 선박의 충돌예방 시스템을 최종적으로 개발하기 위해 먼저 소형어선(30톤미만) 운항자의 요구분석을 수행하였다. 분석을 통해 충돌회피거리, 당직자 배치, 긴급피항시 필요시간, 충돌 및 경보시스템 개발에 필요한 사항 등을 도출하였다. 향후 이를 바탕으로 해상에서의 선박충돌 예방을 위한 신뢰성 높은 충돌경보 알고리즘을 개발 적용하는 등 사용자 편의적인 충돌경보 시스템을 개발하고자 한다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.153-156
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• 2001

최근 들어 두드러지고 있는 승조원의 승선 기피현상에 따른 항해인력 부족현상을 근원적으로 해결하기 위하여 선박 항해 전반에 걸친 자동화 및 지능화에 대한 연구가 활발히 진행되고 있다. 특히 선박의 자동화된 항해를 위해서는 영역전문자 수준의 안전성과 정확성이 보장된 충돌회피 시스템이 요구된다. 충돌회피는 자선에서 이루어지는 해상 장애물들에 대한 피항 행위로 그 판단 기준은 각 장애물에 대한 충돌 위험도에 기반한다. 본 연구에서는 DCPA와 TCPA를 이용한 기존의 기법에 변침도(VDH: Variation Degree of Heading)의 개념을 추가하여 새로운 충돌 위험도 산출 기법을 제안한다. 입력변수가 되는 DCPA, TCPA, VDH의 퍼지 소속함수를 산출하고, 이를 기반으로 퍼지 규칙을 이용하여 세부적인 충돌 위험도를 산출한다. 본 연구에서 제안하는 기법은 충돌 위험도 산출시 장애물의 직선운항뿐만 아니라 곡선운항에 대한 경로예측이 가능하다는 장점을 지닌다. 과거의 변침도가 다음시점의 변침에 영향을 끼침으로써 장애물의 이동 경로에 대한 예측이 이루어지고, 이를 기반으로 보다 세분화된 충돌위험도 산출이 이루어진다. 제안된 기법은 DCPA와 TCPA만으로 충돌위험도를 산출해 낸 연구와 비교.평가하여 성능을 검증한다.

• Journal of Navigation and Port Research
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• v.38 no.4
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• pp.327-333
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• 2014

The Convention on the international regulations for preventing collisions at sea, 1972(COLREGs) defines the collision avoidance principles and various navigation rules for the prevention of collision at sea. In particular, the initial responses to avoid risk of collision are mainly decided by navigation officer's experience and subjective judgement. However, collision accidents could be effectively prevented if the minimum criteria of quantitative initial response are suggested to the junior officers and the cadets who have insufficient sea experience and navigation competency. This study reviewed the COLREGs terms related to the initial response and the existing papers concerned with risk assessment model. A questionnaire survey is also carried out for safe passing distance, degrees of alternating course and initial response distance to avoid collision in accordance with various encounter situations. Base on these results, we propose the proper minimum safe passing distance between the vessels, the initial response distance and required turning angles for alternation in each encounter situations. The suggested criteria of initial response will contribute to the prevention of collision at sea as well as the improvement of gradual navigation technology.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.183-184
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• 2021

선박의 자율운항을 위해서는 선박 충돌회피에 대한 사전 연구가 필요하다. 항해사들의 상황인식과 의사결정에 기여하기 위해 주변 상황 환경을 인식하고 의사결정을 하기까지 걸리는 시간을 지연(latency)이라고 한다. 따라서 연구 목적은 선박 충돌 상황에서 항해사의 의사결정 지연시간을 측정하는 것이다. 연구방법은 항해사를 대상으로 시뮬레이션을 통한 테스트 결과를 분석하였다. 연구결과 항해사가 선박충돌상황시 상황인식과 의사결정간의 상관관계를 도출할 수 있었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.4-6
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• 2011

부유물 부근을 항해하는 선박의 조종 운동에 미치는 부유물의 영향을 파악하기 위하여 선박과 부유물(40피트 콘테이너)을 형상화 하고 선박과 부유물간의 간섭영향을 수치 계산하였다. 이 논문에서 사용되어진 계산 방법은 충돌 회피를 위한 선박의 자동제어시스템과 해상교통제어시스템 및 항만 건설 등을 위한 초기 설계 단계에서 선박 조종성의 예측에 유용할 것이다.