• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.827-832
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• 2004

Up to now a lot of the study on ship collision avoidance systems have proceeded actively. However the rate of ship collision accidents hasn't decreased yet. If there is collision risk in close quarters situation in spite of maneuvering ship for collision avoidance according to the system, only use of TCP A and DCP A as input factor for collision risk decision is not useful to avoiding collision action. For the recent 5 years by the analysis of first observation distance about approaching ship in domestic collision accidents, nearly $45\%$ of accidents is close first observation less than 2 miles. Therefore it is essential part for safety navigations to study for collision avoidance action in close encounter. In this paper, as a fundamental study of supporting collision avoidance maneuvering for navigators, we proposed ship collision avoidance support model in close quarters situation through analysis qf collision accidents to effectively get rid of the causes.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.67-73
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• 2021

The purpose of this study is to obtain a safe area for a passing vessel between anchored vessels by developing a model to predict the collision risk, frequent collisions occur between the anchored vessel and the passing vessel through the anchorage. For this, this study selected the southern anchorage of Busan port, which is the largest harbor in Korea, as the target area and extracted and analyzed VTS (Vessel Traffic Service) data during the period in which anchored vessels were the most waited. The ratio of D/L for each bearing was obtained to determine the safe distance (D) passes based on the length (L) of the passing vessel between anchored vessels. Based on the average domain of the D/L ratio distribution, the percentage of anchored vessels within the scope of the pre-studied ship's domain was analyzed to obtain a domain reflecting the degree of risk of VTSOs. Further research will evaluate and analyze the collision risk of a passing vessel using Domain-watch, the minimum safe distance between anchored vessels, and the safe domain of a passing vessel through anchorage, to develop a model for VTS to manage anchorages more efficiently and safely.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.5
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• pp.1753-1763
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• 2013

In the design phase of sea-crossing bridge projects, ship collision problem is mostly participated in decision of substructure section and it would be performed by risk assessment and impact simulations. Ship collision risk is assessed by probability model which is similar to method II of Guide Specification and Commentary for Vessel Collision Design of Highway Bridge(AASHTO, 2009). However, several factors used in the applicable code are limited to inland waterways or have many local characteristics. Accordingly, it should be needed judgement of engineer or referred to related criteria, research finding. In this study risk assessment for In-cheon bridge and review of existing substructure's impact risk and resistance capacity are performed using the 2010's ship passage data. And then consideration regarding to presumption and applied instance of factors needed for risk assessment and related research findings are performed on the basis of AASHTO Guide's Method. As a result of study, adequate variable region of factors needed for risk assessment is defined and sensitivity analysis for appropriate region is performed. Consequently, factors that should be applied carefully or needed for direct analysis of local data are confirmed. This research could be fundamental material to risk assessment related to design for sea-crossing bridge taken into account ship collision.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.6
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• pp.603-608
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• 2014

In the maritime traffic environment, the near-miss between vessels is the situation approaching on collision course but collision accident is not occurred. In this study, in order to calculate the near-miss between navigating vessels, the discriminating equation using ship bumper theory and vessel position clustering methods are proposed. Applying proposed module to the vessel trajectories of the WANDO waterway, we assessment navigational risk factors of vessel type, navigational speed, meeting situation.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.43-57
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• 2023

The hypervelocity impact simulations of space objects and structures are performed using LS-DYNA. Space objects with spherical, conical, and hollow cylindrical shapes are modeled using the Smoothed Particle Hydrodynamics (SPH). The direct and indirect impact zones of a space structure are modeled using the SPH and finite element methods, respectively. The Johnson-Cook material model and Mie-Grüneisen Equation of State are used to represent the nonlinear behavior of metallic materials in hypervelocity impact. In the hypervelocity impact simulations, various impact conditions are considered, such as the shape of the space object, the thickness of the space structure, the impact angle, and the impact velocity. The shapes of debris clouds are quantitatively classified based on the geometric parameters. Conical space objects provide the worst debris clouds for all impact conditions.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.3
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• pp.290-295
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• 2011

On the basis of DCPA(Distance to Closest Point of Approach) and TCPA(Time to CPA), the conventional algorithms for collision avoidances have a drawback that the '72 CORLEGs(International Regulations for Preventing Collisions at Sea, 1972) has not taken into account to prevent collisions between ships. In this paper, the proposed algorithm decides whether the own ship is a give-way vessel or a stand-on vessel by observing the relative bearing of the encountered ship. To determine the ship position and time for collision avoidance, the proposed algorithm utilizes the ellipse model for ship safety domain. The computer simulation is done to represent the process of adversive behavior. Using the proposed method, the past maritime accident is analyzed. The proposed method can be effectively applied to collision avoidance by CORLEGs even when the target ship's navigational lights is invisible in poor weather and/or in the restricted visibility.

• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.235-245
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• 2007

UUV(Unmanned Underwater Vehicle) should possess an intelligent control software performing intellectual faculties such as cognition, decision and action which are parts of domain expert's ability, because unmanned underwater robot navigates in the hazardous environment where human being can not access directly. In this paper, we suggest a RVC intelligent system architecture which is generally available for unmanned vehicle and develope an autonomous navigation system for UUV, which consists of collision avoidance system, path planning system, and collision-risk computation system. We present an obstacle avoidance algorithm using fuzzy relational products for the collision avoidance system, which guarantees the safety and optimality in view of traversing path. Also, we present a new path-planning algorithm using poly-line for the path planning system. In order to verify the performance of suggested autonomous navigation system, we develop a simulation system, which consists of environment manager, object, and 3-D viewer.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.26-27
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• 2019

This study is to calculate the Real-Time contact point of ellipses between the vessels ships by Ship's Bumper Theory. The Real-Time contact point of ship's bumper ellipses can be used the important tool to feel the perceived risk evaluation of ship's collision risk by VTS operator. In this paper, The warning information to feel the risk of collision between the vessels in advance is able to help them for VTS operation, We will study the technique to certify the perceived risk of collision from several different angles by programming.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.565-567
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• 2012

최근 목포 해상교통관제(VTS)구역 내 만곡부 항로상에 연륙교가 건설됨에 따라 연륙교를 통과하는 선박들의 충돌사고 위험성이 높아질 개연성이 커졌다. 해당 수역에서의 선박교차와 관련된 선박교통의 분석을 집중적으로 실시함으로써 향후 해상교통관제 업무와 관련하여 주의하여야 할 사항 및 대책들을 제시하였다. 특히 교차빈도가 높은 여객선과 예부선 간의 C PA를 분석함으로써 해상교통사고의 위험을 줄이기 위해 확보되어야 할 최소안전거리에 대해서 중점적으로 검토하였다.

• 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.