• 한국항해항만학회지
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• 제34권6호
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• pp.405-415
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• 2010

본 논문에서는 현재 건설 중인 목포 대교와 통항 선박 사이에 발생 가능한 충돌 위기를 평가하기 위한 선박-교량 충돌 모델(Real-Time Bridge-Vessel Collision Model, RT-BVCM)을 제안하였다. RT-BVCM의 수학 모델은, 항행환경으로 선박이 이탈하게 되는 원인 확률과, 선박의 크기와 교량 구조로 인한 기하학적 확률, 선박의 충돌 침로와 정지거리에 기인한 충돌 회피 실패 확률 등으로 구성하였다. 그리고 이러한 확률적인 수학 모델은 1부터 5까지의 위기수준을 갖는 위기지수로 나타냈다. 본 연구에서 제안한 RT-BVCM은 기존 AASHTO(American Association of State Highway and Transportation Officials)에 제시된 선박-교량 충돌 모델과 달리, 충돌 회피를 위한 충분한 시간을 확보할 수 있는 장점이 있다. 3,000 GT와 10,000 GT 실험 선박에 다양한 항행환경을 적용한 시뮬레이션 실험 결과, 제안한 모델이 목포 대교와 통항 선박 사이의 충돌위기 평가 모델로 타당함을 확인하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.320-323
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• 2008

In this study the effect of collision model was evaluated in spray field by CFD. A collision is basically the interaction between droplets and criteria of collision is determined by drop Weber number, impact parameter, and drop-size ratio. Early developed collision model considered coalescence and grazing collision with the exchange of momentum. However in experimental research there were bouncing, coalescence, reflexive separating and stretching separating in interaction between droplets. In this study the collision considering such complex phenomena is modeled and was compared with the basic collision model.

• 전기전자학회논문지
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• 제7권2호
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• pp.253-259
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• 2003

좋은 3D 엔진이란 객체들의 상호 작용을 실세계와 유사하게 표현하는 물리학 엔진을 말한다. 충돌은 이런 상호작용 중의 하나이며, 충돌 유무 검사와, 충돌 지점, 충돌후의 반응을 다룬다. 대부분의 물리학 엔진과 같이 충돌 검사도 정확하게 검출하려면 많은 시간이 소요된다. 그러나 요구되는 정밀도만 만족하는 모델 사용으로 검출시간을 조절 할 수 있다. 그러므로 요구되는 정밀도와 시간에 따라 충돌 검출 모델을 선정하여야 한다. 본 논문에서는 충돌 검출 모델들을 정확도에 따라 7단계로 구분하여 구현하고 실험했다. 이를 통해 시간과 정확도의 연관 관계를 분석하고, 이에 따른 충돌 검출 모델을 선택하기 위한 기준을 제시하고자 한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권2호
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• pp.188-198
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• 2013

In constructing a collision avoidance system, it is important to determine the time for starting collision avoidance maneuver. Many researchers have attempted to formulate various indices by applying a range of techniques. Among these indices, collision risk obtained by combining Distance to the Closest Point of Approach (DCPA) and Time to the Closest Point of Approach (TCPA) information with fuzzy theory is mostly used. However, the collision risk has a limit, in that membership functions of DCPA and TCPA are empirically determined. In addition, the collision risk is not able to consider several critical collision conditions where the target ship fails to take appropriate actions. It is therefore necessary to design a new concept based on logical approaches. In this paper, a collision ratio is proposed, which is the expected ratio of unavoidable paths to total paths under suitably characterized operation conditions. Total paths are determined by considering categories such as action space and methodology of avoidance. The International Regulations for Preventing Collisions at Sea (1972) and collision avoidance rules (2001) are considered to solve the slower ship's dilemma. Different methods which are based on a constant speed model and simulated speed model are used to calculate the relative positions between own ship and target ship. In the simulated speed model, fuzzy control is applied to determination of command rudder angle. At various encounter situations, the time histories of the collision ratio based on the simulated speed model are compared with those based on the constant speed model.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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• pp.83-88
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• 2006

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 by Prof. Jeong in his relevant $articles^{[2][3][4][5]}$. And as a grope in collision risk evaluation field, this paper applied the new model in appraising the collision risk, suggested how to decide the safe range of own ship’'s action. Moreover this paper also analyzed theoretically how to determine the coefficients as describes in the new modification model formula, and suggested the appropriate values as applicable.

• 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.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.380-385
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• 2008

3 DOFs model for the collision analysis of a bridge super-structure and a super-structure of the navigating vessels were proposed and analyzed. The collision event between the super-structure of vessel and the super-structure of bridge are different from the normal collision event that collided at sub-structure of bridge. Because of its moment arm, the stability force of vessel could affect to the collision behaviors. To consider this effect, 3 DOFs model including two translation DOFs and one rotational DOF were introduced. The restoration forces of the collision system were considered as nonlinear springs. The equations of motion were derived if form of differential equations and numerically solved by 4th order Runge-Kutta method. The accuracy and the feasibility of this model were verified by the numerical example with parameter of moment arm length.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1891-1896
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• 2004

The present article proposes a new droplet collision model including the stretching separation regime and the formation of satellite droplets. The new model consists of a several equations to calculate the post-collision characteristics of colliding droplets and satellite droplets. These equations are derived from the energy balance of droplets between before and after collision. For binary collision of water droplets, the new model shows good agreement with experimental data for the number of satellite droplets. Nevertheless, it is thought that, in order to guarantee the generality of the new model, the improvements should be performed to consider the effects of the bouncing and the reflexive separation, which is essential process in the collision of hydrocarbon droplets.

• 정보처리학회논문지B
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• 제11B권7호
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• pp.821-830
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• 2004

본 논문에서는 지표면을 향해 낙하하는 자유 물체의 충돌 현상에 대해 모델링하고자 한다. 이를 위해 최소한의 근원적인 요소를 찾아서 최대한의 다양성을 제공하고자 한다. 몰입감있는 가상환경 구축을 위해 보다 사실적이고 논리적으로 동작하는 충돌 현상을 표현하는데 설계의 초점을 둔다. 이를 위해, 낙하 물체의 재료(material)적 특성에 대한 범위(domain)를 결정하고 우성력(dominant forte)을 선택할 것이며, 힘과 지표면에 대한 모델링을 구축할 것이다. 이는 충돌 후 발생하는 결과들을 정량적인 면뿐만 아니라 정성적인 면에서도 충족시킬 수 있다. 아울러 기존에 많은 연구가 진행된 충돌 검출 보다는 충돌 반응 양상에 모델링의 초점을 둘 것이다.

• 천문학논총
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• 제12권1호
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• pp.149-157
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• 1997

The collision model of the disk, based on collisions between the particles in the disk, is summarized. The dependence of disk stability on the collision of the particles is demonstrated. The energy spectrum produced in the disk is numerically calculated. We concluded that the results are not largely different from those of the standard disk model. It implies that the collision of the particles inside the disk may be considered here.