• The KSFM Journal of Fluid Machinery
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• v.16 no.2
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• pp.5-9
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• 2013

The aim of present study is to evaluate the stability of GM(Metacentric Height) calculation and investigate the damping effect of free rolling test. Moreover, GZ(Righting arm in stability) curve shows that it can provide reasonable design conditions for Fish boat. The roll damping characteristics of the improved model for an 7.9 ton class fishing boat are investigated through the free roll test in towing tank. The safety and boarding sensitivity are evaluated by GM calculation and roll motion period. Therefore, the results in this paper describe that the effect for improved hull is more improved than the original hull.

• Proceedings of the KWS Conference
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• v.43
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• pp.213-215
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• 2004

Water jet propulsion system has high efficiency on middle to high speed, and it provides better safety than conventional screw propeller because it has not projected propeller and rudder. So many leisure boat and high-speed ferries use this propulsion system. We developed water-jet propulsion unit for small planning boat, and launched that in the boat, after that we tested water-jet unit in the lake. As a result, we certify heat dissipation at the bearing housing and reverse duct's shape for neutral position are important at the design, and alignment water-jet unit and keel line are important at the launching, and ship's resistance performance and jet's propulsion performance also are needed to consideration.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.148-157
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• 1993

A study was conducted to evaluate the effect of enamel coating on boat hull drag. The results were compared with drag required for varnished uncoated boats. Models of rice barge and fishing boat were used in this study. The speed range of 0.6 to 1.5㎧ at different loads varying from 6 to 9 kg for rice barge and 4.6 to 6.4kg for fishing boats were used during testing. The total weight of the coated and uncoated boats were kept the same. It was observed that the drag force required by the coated boats was less than identical uncoated ones at all speeds and loads. For both uncoated and coated the drag required increased with speed. The maximum recorded reductions in drag were 26% for the rice barge and 28% for the fishing boat model.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.606-612
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• 2010

This study took advantage of NC processing technique in order to recreate design in development process of leisure boat based on the Korean boats and ships. CNC milling is an area which is concerned in automation process of boat production and needs sophisticated software, equipment and professionals to pilot it. The progress of manufacture begins when the surface model creation and simulation being done using CAD/CAM software. In this process, the needs such as 3D design, NC processing data, plug lamination and partition processing appear as detailed steps. The study completed these detailed steps and also the application example has been studied with presenting engineering potentialities.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.880-885
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• 2005

RIB(Rigid Inflatable Boat)형 보트는 선체, 팽차식 선측튜브를 적용한 고속 다목적보트로 뛰어난 내항성능과 높은 안전성으로 해외 선진국에서는 해양레저 활동에 적합한 신개념 고부가가치 보트로 각광받고 있으나 국내에는 레저용 RIB 보트의 제작 및 개술개발 실적이 전무한 실정이다. 이에 본 연구에서는 고속이면서도 안정성 및 편의성을 고려한 레저용 RIB의 최적선형 설계 및 공간배치 연구, 하이파론 선측튜브 설계, 조선학적 제계산을 통한 주요성능 검토 등을 통하여 최근 급증하고 있는 해양레저 수요에 대응한 6m급 RIB형 레저보트를 개발하고자 하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.91-96
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• 2011

The ship working environment of combat service support boat is very inferior to the ground working environment. For this reason, the crew of a combat service support boat suffer from an occupational disease such as hardness of hearing. Owing to its small size and low status, the improvement of its working and residential environment is occasionally ignored and its indoor noise was not fully investigated. In this study, for improving its residential environment indoor, the indoor noise of its shipboard compartments was analysed.

• Journal of Welding and Joining
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• v.32 no.1
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• pp.34-39
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• 2014

There are so many difficulties of melt bonding mainly applied for hull construction of a aluminum alloy small boat. For resolving this problem, Friction stir welding(FSW) in non-melting solid state welding Process generally is applied in the transport industry. This paper is studied the joining strength characteristics and macrostructure according to dissimilar aluminium 5000/6000 alloy joining for a small boat applied for this FSW technology. It is reported that difference of joining strength in accordance with the direction of rotation in case of friction stir welding between dissimilar metals(Al/Cu, Al/Fe) is also highly large. In this study, Test is carried out by making the specimen according to the direction of rotation of dissimilar aluminium alloy joining.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.710-716
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• 2005

The objective of the present study is to design a hull form of a 9.77 ton class trimaran for use as a Pleasure boat around the bay of Gyounggy. The boat will be made of fiber reinforced plastics and equipped with a 650 hp diesel engine with a conventional water jet propulsion system and the maximum speed be 25 knots after fully loaded. In the present study, the optimal configuration such as relative location of outriggers of the 9.77 ton class trimaran is selected and the resistance characteristics are carefully studied through a series of model tests. The general arrangement of the boat are also considered in the final decision of the hull form.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.3
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• pp.1-10
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• 1984

The computer programs of effective horsepower estimation of small fishing boat were developed, which was based on the statistical analysis of model test results. From the EHP estimation by these program and experimental model tests of practical fishing boats, the estimation accuracy was verified with maximum deviation of about 10 percent. Also, the EHP estimation accuracy was practically applied to initial design of four small fishing boats, and after the tank tests, the EHP reduction of the order of 15 to 25 percent was confirmed, as compared with existing ships. Moreover, a computer aided design procedure of fishing boat's hull form has been proposed in this study. The practical use of this procedure of fishing boat's hull form has been proposed in this study. The practical use of this procedure was demonstrated with the hull form design results of several fishing boats.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.506-515
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• 2005

Novel ships are commonly required iterative hull form modifications until she get reputation for new marine environment. Small FRP boats are manufactured in a identical shape with a mould. It implies that every modification step requires great time and expense which makes it difficult to improve the hull form promptly. Domestic hull form of small fishing boat of force has been evolved from the traditional hull form of developable shape. Utilizing this typical developable characteristics of small boats, ,New mouldless production method for FRP boat has been suggested and it is confirmed that the method is recommendable for a petty order of hull in evolving period of hull form development.