• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.46-56
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• 2000

This paper is related with one of safety plans to rescue a damaged-ship whether by collision, grounding or internal accident. We discuss the problem on course stability of damaged-ship while towed under severe wind pressure. The characteristic equation to assess the stability on course, is derived from sway and yaw coupled motion of towing and towed vessels with wind effect. Through the numerical calculation on course stability of towing and towed vessels system, the relationship between the course stability of a towed damaged-ship and wind direction or towrope length, is clarified with the parameters of weather and damage conditions.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.1
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• pp.50-59
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• 2000

This paper presents a brief outline of dynamic stability of a damaged ship at final stage of flooding in rough beam wind and waves. One degree-of-freedom, roll equation is adopted with effects of flooding water and external forces due to wind and waves, but without effect of sloshing. We discuss the dynamic stability of the damaged ship in terms of capsizing probability based on risk analysis, the method of which was firstly proposed by Umeda et al.[6] to high speed craft in intact condition. As a result, we can evaluate the dynamic stability of the damaged ship in probabilistic manner according to sea state, operating condition and damage situation.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.435-447
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• 2005

The 24th ITTC Specialists Committee on Stability in Waves is conducting an international benchmark study where numerical methods for the calculation of ship motion in damaged condition are compared on the basis of specified tests in order to assess the present state of the art in this field. The study is finished and some results are presented in this paper providing an initial insight into the status of damage models and numerical methods and a collective assessment of their performance. The preliminary analysis has shown that current methods are satisfactory, capturing the fundamental physical performance of damaged ships in specified conditions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.4
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• pp.236-243
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• 2013

Offshore wind turbines has to be proved against accidental events such as ship collision. In this study, ship collision fragility analysis of offshore wind turbine is done. Dynamic collision analysis is accomplished by considering soil foundation interaction and fluid structure interaction. Uncertainties due to ship weight and speed, angle are also considered. By analyzing dynamic response of offshore wind turbine, fragility curves are obtained for different damage levels. They can be used for restricting boat speed around the wind turbine and allowable size of the boat for inspection and for other purposes. Results of the fragility, it was confirmed fragility of collision speed of bulk ship of 30,000DWT and 850ton barge ship.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.865-870
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• 2005

Because there are only a limited number of means of action that are available for the master to pursue in the event of flooding, onboard decision support system has been required. The majority of systems activated during a flooding emergency (such as watertight and semi-watertight doors, bulkhead valves, dewatering pumps etc.) almost exclusively aim to restore a sufficiently high level of subdivision to prevent flooding from spreading through the ship. Even though assuming the flooding scenario is not catastrophic, the use of ballast tanks can be an additional and very effective tool to ensure both prevention of flooding spreading and also improve ship stability. This paper describes an optimization algorithm devised to choose the set of ballast tanks that should be filled in order to achieve an optimal response to a flooding accident.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.75-80
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• 2005

Because there are only a limited number of means of action that are available for the master to pursue in the event of flooding, onboard decision support system has been required The majority of systems activated during a flooding emergency (such as watertight and semi-watertight doors, bulkhead valves, dewatering pumps etc.) almost exclusively aim to restore a sufficiently high level of subdivision to prevent flooding from spreading through the ship. Even though assuming the flooding scenario is not catastrophic, the use of ballast tanks can be an additional and very effective tool to ensure both prevention of flooding spreading and also improve ship stability. This paper describes an optimization algorithm devised to choose the set of ballast tanks that should be filled in order to achieve an optimal response to a flooding accident.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.14-21
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• 1994

The studios on the stability of damaged ships have been carried out continuously to prevent frequent damages or sinkings which cause large loss of life and fortunes. For dry cargo ships, continuing losses have resulted in new legislation of the probabilistic damage stability. IMO has developed requirements for the subdivison and damage stability of dry cargo ships based on probabilistic concepts. The calculation of the probabilistc damage stability is a complicated and iterative job hence development of computer programs is indispensable. In this research, programming of the probabilistic damage stability according to new requirements has been done and the results were compared with those carried out by the other foreign packages. New algorithm using a grid model in a transversal section was introduced to reduce efforts in preparing input data for damage scenarios and as a result, has brought significant improvement in efficiency and performance.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.59-60
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• 2001

산업의 발전과 함께 해양환경 중에서 사용되는 항만시설과 해양구조물 등을 비롯하여 철강재로 제작되는 각종 구조물, 공업용수배관, 열교환기, 선박 등의 기계장치나 각종설비는 그 사용 환경이 다양해지고 오염되면서 부식손상이 발생되어 지고있다. 더욱이 강전해질의 해양환경 중에서 기계적인 충격 침식과 더불어 전기화학적인 부식이 중첩하여 발생하는 경우에는 침식과 부식 이 상호간에 가속하는 상승효과 때문에 각종 기계장치 및 설비의 수명에 대한 안정성 확보가 어렵다. (중략)

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.69-70
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• 2011

최근 해저지진의 활동에 따른 극한 쯔나미 파랑이 해안도시와 항만에 어마어마한 손상을 가져오고 있다. 전세계에 걸쳐 특정해역에서는 강한 정진형태의 부진동과 처오름이 관측되고 있다. 한반도에서는 그렇게 빈번한 발생을 나타내고 있지는 않으나, 과거기록을 보면 동해에서 몇 개의 중요한 발생사례도 존재한다. 본 연구에서는 특히 만이나 내수해역에서 최근 해저지진의 발생 추이를 분석하고 이에 따른 쯔나미 발생 메카니즘을 해석하여 새롭게 내수역에서의 수치모델에의 적용을 통해 공진을 통한 쯔나미 파랑의 변환을 다루어 통항선박에 대한 안정성 확보에 기초자료를 제공하고자 하였다. 내수역에서의 쯔나미 파랑에 대한 반응을 정합성 및 웨이블릿 해석으로 탁월 주기와 지속시간에 대한 분석으로 파악하였으며, 쯔나미파의 입사와 독립적인 공진모드의 도출은 쯔나미 재해의 경감을 위한 시설물 및 재난지역을 식별하는데 도움을 주고, 나아가서는 장래 재난에 대한 적절한 대비에 기여할 수 있을 것으로 본다.

• Journal of the Society of Naval Architects of Korea
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• v.43 no.4 s.148
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• pp.451-459
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• 2006

When a ship is damaged and flooded, the motion of the damaged ship is significantly influenced by the flooding water dynamics. The flooding water in the damaged ship has been treated as a lumped mass under the quasi-static assumption in most of previous researches. To calculate the motion of damaged ship rigorously, it is necessary to analyze the coupled dynamics of flooding water. In this study, a series of numerical and experimental studies is conducted for the damaged part of ITTC RORO passenger. FLOW3D is used for investigating the feasibility of the state of the art CFD technique. An applicability of the coupled motion analysis of damaged ships can be confirmed by agreement between the numerical results and the model experiments. A CFD technique is considered for the numerical modeling of the dynamics of flooding water.