• 한국구조물진단유지관리공학회 논문집
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• 제1권1호
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• pp.75-87
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• 1997

To study the behavior a deck when it was collide with the ship approaching to the deck to berth, it was analyzed the effect zone by the ship collision which consists of deck slab and PC piles of the quay. The numerical technique is used to simulate the behavior of the deck when the ship hit the expansion joint of deck between the deck slabs. The failure behavior and zone of the deck are determinated by the comprehensive numerical study. The impact energy by the ship is also evaluated. It is concluded that these numerical analysis gave a reasonable estimation of the remedial area of the deck damaged by ship collision.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.7-11
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• 2004

Maritime safety and marine environmental protection are the most important topic in marine society. But, so many marine accidents rave been occurred with the development of marine transportation industry. On the other side, ship is being operated under a highly dynamic environment and many factors are related with ship's collision Nowadays, the increasing tendency to the human errors of ship's collision is remarkable, and the investigation of the human errors has been heavily concentrated. This study analysed on the human errors of ship's collision related to the negligence of lookout and classified basic error type using GEMS(Generic Error Modeling System) dynamic model.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.663-666
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• 2004

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. AF is computed for each bridge component and vessel classification. The summation of AFs computed over all of the vessel classification intervals for a specific component should equal the annual frequency of collapse of the component. The designer should use judgment in developing a distribution of the vessel frequency data based on discrete groupings or categories of vessel size by DWT. In the present study the effect of vessel classification on the annual frequency of collapse in the ship collision risk assessment is investigated by illustrative numerical examples based on the vessel frequency data of the domestic harbor. The DWT interval for larger vessels has more effect on the ship collision risk. Therefore the expert judgement in determining the larger DWT interval is required because the design impact lateral resistances of bridge components depend on the ship collision risk.

• 대한조선학회논문집
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• 제56권1호
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• pp.58-65
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• 2019

The stability, reliability and efficiency of a smart ship are important issues as the interest in an autonomous ship has recently been high. An automatic collision avoidance system is an essential function of an autonomous ship. This system detects the possibility of collision and automatically takes avoidance actions in consideration of economy and safety. In order to construct an automatic collision avoidance system using reinforcement learning, in this work, the sequential decision problem of ship collision is mathematically formulated through a Markov Decision Process (MDP). A reinforcement learning environment is constructed based on the ship maneuvering equations, and then the three key components (state, action, and reward) of MDP are defined. The state uses parameters of the relationship between own-ship and target-ship, the action is the vertical distance away from the target course, and the reward is defined as a function considering safety and economics. In order to solve the sequential decision problem, the Deep Deterministic Policy Gradient (DDPG) algorithm which can express continuous action space and search an optimal action policy is utilized. The collision avoidance system is then tested assuming the $90^{\circ}$intersection encounter situation and yields a satisfactory result.

• 한국항해항만학회지
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• 제31권4호
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• pp.281-287
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• 2007

Human factors have been considered the primary reason of marine accidents. Especially, the collision between vessels is mostly mused by human behavior. However, there have not been many researches to clarify the reason of marine accidents mused by human factors quantitatively. In order to understand human factors and to enhance safe navigation systematically, using a full mission ship-handling simulator, we've investigated the characteristics of avoiding behavior taken by mariners. Further in order to apply the characteristics more widely and effectively, it's necessary to formulate the standard behavior for ship-handling in the condition of collision avoidance. Is this study, therefore, we intended to propose the concept to model the mariner's standard behavior on the handling of collision avoidance as the first step. As a result, we confirmed the contents of information processing in ship-handling that mariner's generally taking to avoid collision.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 추계학술발표회
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• pp.7-11
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• 2003

선박충돌사고는 많은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있으며, 특히 인적요인에 의한 충돌사고가 가장 큰 비중을 차지하고 있다. 이러한 선박충돌사고 원인분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 선박충돌사고 인적요인 모델을 구축하고, 선박충돌사고를 감소시키기 위한 가장 효과적인 대책을 수립하기 위한 정책요소론 제시하고자 한다. 본 연구의 수행을 위해 ]nM법에 의한 충돌사고원인의 구조분석을 인과지도상의 정량적, 정성적, 피드백 루프로 변환하였다. 그리고 표준시뮬레이션모델과 8가지 정책시뮬레이션모델을 20년간(1993-2012) 시뮬레이션을 수행하였다.

• 한국항해항만학회지
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• 제27권5호
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• pp.493-498
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• 2003

선박충돌사고는 많은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있으며, 특히 인적요인에 의한 충돌사고가 가장 큰 비중을 차지하고 있다. 이러한 선박충돌사고 원인분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템 다이내믹스법을 이용하여 선박충돌사고 인적요인 모델을 구축하고, 선박충돌사고를 감소시키기 위한 가장 효과적인 대책을 수립하기 위한 정책요소를 제시하고자 한다. 본 연구의 수행을 위해 FSM법에 의한 충돌사고원인의 구조분석을 인과지도상의 정량적, 정성적, 피드백 루프로 변환하였다. 그리고 시뮬레이션 기간을 20년간(1993-2012)으로 설정하여 표준시뮬레이션모델과 8가지 정책시뮬레이션모델에 대해 시뮬레이션을 수행하였다.

• 해양환경안전학회지
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• 제24권3호
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• pp.339-345
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• 2018

Sunrise and sunset times differ depending on location and date. Previous studies conveniently but monotonously applied day and night times set up. This research defined the daytime and nighttime while considering the time of twilight according to the date and the location of ship collision accidents. Classifying the frequency of ship collision accidents with this standard, we conducted a chi-squared test for the difference between daytime and nighttime. The frequencies of ship collision accidents according to daytime and nighttime was compared by season, month, and time, and all of them showed statistically significant differences. The highest number of daytime ship collisions was 11.6 %, in June, and nighttime collisions peaked at 13.7 %, in December. The most frequent hour for daytime ship collisions was 0700h-0800h, at 10.2 %, and nighttime collisions peaked between 0400h-0500h, at 16.9 %. It is clear that the criteria used in previous studies cited was applied without any theoretical basis and likely only for the convenience of the researchers. It was found that results depend on what criteria are applied to the same research data. This study shows that statistical analyses of marine accidents, traffic volume, and congestion density should be carried out quantitatively while considering daytime and nighttime hours for each particular location and date.

• 해양환경안전학회지
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• 제24권3호
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• pp.319-324
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• 2018

The collision problem is one of the design factors that must be carefully considered for the risk of collision occurring during the operation of ships and offshore structures. This paper presents the main results of the ship collision study, and its main goal is to analyze potential crash scenarios that may occur in the FLNG (Floating Liquefied Natural Gas) considering the likelihood and outcome. Consideration being given to vessels visiting the FLNG and surrounding vessels navigating around, such as functionally supported vessels and offloading carriers. The scope includes vessels visiting the FLNG facility such as in-field support vessels and off-loading carriers, as well as third party passing vessels. In this study, based on QRA (quantitative risk assessment), basic research methods and information on collision are provided. Based on the assumptions and methodologies documented in this study, it has been possible to clarify the frequency of collision and the damage category according to the type of visiting ship. Based on these results, the risk assessment results related to the collision have been derived.

• 한국항해항만학회지
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• 제31권2호
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• pp.121-126
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• 2007

Evaluation of collision risk plays a key role in developing the expert system of navigation and collision avoidance. This paper presents a new collision risk model formula that is one modification model on the basis of one approach to the evaluation of collision risk using sech function produced in earlier studies. And as a tool of the evaluation field of ship collision, this paper applied the new model in appraising the collision risk and represented how to decide the safe range of own ship's action. Moreover this paper also analyzed theoretically how to determine the coefficients as described in the new modification model, and suggested the appropriate values as applicable.