• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.216-221
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• 2005

Many tanks such as a fresh water tank, an aft peak tank and oil tanks are arranged in the engine room and aft part areas of the ship. By added mass effect of the fluid inside the tanks, the natural frequency will be changed according to filling height of the tank. For this reason, there is possibility of occurrence of excessive vibration by resonance between natural frequencies of local structure and excitation frequencies of the propeller or main engine. Therefore, calculation of natural frequencies is required for structure for many types of tank which are contacting with water or oil to consider added mass effect for anti-resonance design at design stage. In this study, a case of structure damage on the fresh water tank for 2600 TEU container vessel is introduced. In addition, natural frequency analysis and vibration measurement have been performed to investigate vibration characteristics for excessive vibration control.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.26-31
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• 2007

After CSR is in effect, a matter of concern is how many to increase in terms of weight due to apply it to the ship and what difference it is comparing between existing rule and CSR rule. The concepts of CSR are to make the ship safer, more robust. and the design requirement clearer. Furthermore it pursues longer life of ship in fatigue strength. By reasons of those, most of requirements are stronger than before. Therefore many part of ship should be reinforced and the weight of ship can be increased. Under those circumstances, the builder should make an effort to define the CSR and to find the methods to manage well this situation. In this study, we performed 3D Cargo hold and Fine-mesh F.E analysis and deduced a conclusion and introduced new detail design.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.85-92
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• 2015

In general, when ships are designed, structural strength and fatigue strength must be verified based on the relative rules respectively. In case of Slurry Iron Sand Carrier designed to carry Iron-Sand saturated at water content, there is no special consideration of fatigue strength analysis. However, this vessel is similar to Ore Carrier in consideration of the overall characteristics of loaded cargo and the shape of cargo hold. Therefore we verified fatigue strength based on fatigue analysis procedure of ore carrier in DNV Rules and carried out the study for improving of fatigue strength of Slurry Iron Sand Carrier.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1382-1384
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• 2002

The flooded type battery is used for solar lighting system. Because the characteristic of flooded type battery is the short life time, the maintenance cost is high. So the using flooded type battery in this system is inappropriate. The valve regulated lead acid batter.(VRLA) is the maintenance free and cycle service purpose. This paper presents the development of control system and monitoring system to applied VRLA battery for maintenance free and long life time in system.

• Special Issue of the Society of Naval Architects of Korea
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• 2008.09a
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• pp.133-135
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• 2008

For complying with the increasing number of ships construction, it's required that not only for minimizing the period of construction in Skid Berth also maximizing application proportion of Skid Barge, The full-ship load out construction method required indispensably.

• Journal of Ship and Ocean Technology
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• v.11 no.2
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• pp.26-33
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• 2007

For the assessment of the retardation of fatigue crack propagation behavior due to overload, new FE analysis algorithms considering compressive residual stress redistribution near crack tip was proposed in this paper. The size of plastic zone near crack tip was obtained by elasto-plastic analysis and it was compared with Irwin's equation. The amount of residual stress redistribution was assessed by subsequent elasto-plastic analysis, and the difference of residual stress distributions between constant amplitude load and overload was obtained. In the analysis of fatigue crack propagation, the applied SIF range was evaluated by ASTM E647, and the effect of residual stresses on crack propagation was considered using the effective SIF concept. The test results of crack propagations were compared with the predicted data obtained by the analysis.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.87-92
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• 2009

CSR for bulk carrier has been required 25 years operation life in North Atlantic condition. As the fatigue life requirement of ship structure is increased it is necessary to study to satisfy the fatigue life which is much severe. Therefore from the fatigue analysis, especially fatigue strength for double bottom & lower stool connection area is not enough. To satisfy the fatigue life, it needs to increase double bottom strength or insert thicker plate. In this study, the consideration though structure modification have been doe with 81K bulk carrier and to find the solution of fatigue problem.

• Special Issue of the Society of Naval Architects of Korea
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• 2017.10a
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• pp.19-27
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• 2017

In spite of adoption of Intact Stability Code Part A as mandatory, the accidents have been occurred frequently caused by dynamic stability. Therefore International Maritime Organization (IMO) is revising the Intact Stability Code to prevent the cause of accidents. The result of 4th meeting of Sub-committee on Ship Design and Construction (SDC), five mode of the cause was defined and establishing each draft regulations. We consider physical background, mathematical description, draft regulations for five failure mode and sample calculations for ships built by STX Offshore & Shipbuilding.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.94-96
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• 2013

Since LNG has explosive properties and difficulty to handle, it was avoided using LNG as fuel. However, recently LNG has been considered as alternative fuel of HFO. Several LNG fuel supply system has developed. Furthermore, STX ONS is developing LNG fuel bunkering system and bunkering shuttle. Bunkering shuttle carries out refueling LNG fuel while LNG fuel ship is on cargo work. In case of emergency, bunkering shuttle breakaway from the ship but a little amount of LNG falls down on deck. It can disperse to cargo work area also can explode. In this case LNG dispersed on deck was not considerable.

• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.90-93
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• 2013

RAM study has been used for various range of industry such as chemical, electronics, defense industry. Recently, in the offshore & shipbuilding industry, demand of owners to analysis risk has been increased. RAM study is a quantitative pointer to risk based design and provides effective method for improvements. This article shows the result of RAM study for LNG fuel supply system. The result provides information to improve design. This study shows how result of risk assessment affects the design of LNG fuel supply system.