• 한국해양공학회지
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• 제11권3호
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• pp.89-94
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• 1997

In the design of high speed fishing vessel, its hull form has to be decided from a view point of resistance and propulsion performance without negelction of seakeeping characteristics. In spite of many efforts, the performance improvement by hull form itself has its limitations, specially for high speed craft. In this paper, the development of performance of resistance and seakeeping improving appendage for high speed planing hull on behalft of the hull form of fishing vessel has been introduced. The developed appendage verified its effectiveness in the full scale test.

• 대한조선학회논문집
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• 제41권1호
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• pp.64-69
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• 2004

In recent years, Medium size high speed Ro-Pax vessel has appeared at European sea and especially Agean sea is a center of operating in this type of Ro-Pax. This vessel operates its high Froude number range and requires higher engine power due to considerably increased resistance in comparing to large Ro-Pax in high speed range. SHI has investigated this kind of high speed Ro-Pax in accordance with market requirements and developed more advanced vessel to meet the future market needs. Process of hull form development, model test results and design of general arrangement results are introduced in this paper.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.691-698
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• 2020

In this study, the effects of hydrodynamic interceptors on a high-speed vessel were investigated to identify the operating principle based on experiments. Model tests were performed using a high-speed towing carriage. The resistance, trim and rise of Center of Gravity (CG) of the high-speed vessel were measured for various ship speeds and interceptor heights. As the interceptor height increased, the trim and rise of CG were reduced. In order to quantitatively analyze these phenomena, the pressure at the stern bottom was measured using tactile sensors. The reliability of the measured results from the tactile sensors was verified through repeat tests. The pressure on the stern bottom increased in proportion to the interceptor height, as the interceptor partially blocked the flow there. Then, the trim was reduced. However, as the ship speed increases, the pressure at the location close to the interceptor decreases when the interceptor height is small, leading to increased trim. Therefore, the interceptor height for running attitude control should be carefully determined considering multiple factors in the operating condition of the high-speed planing hull.

• Structural Engineering and Mechanics
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• 제59권4호
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• pp.683-701
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• 2016

Safety is the prime concern for a high-speed railway bridge, especially when it is subjected to a collision. In this paper, an analysis framework for the dynamic responses of train-bridge systems under collision load is established. A multi-body dynamics model is employed to represent the moving vehicle, the modal decomposition method is adopted to describe the bridge structure, and the time history of a collision load is used as the external load on the train-bridge system. A (180+216+180) m continuous steel trussed-arch bridge is considered as an illustrative case study. With the vessel collision acting on the pier, the displacements and accelerations at the pier-top and the mid-span of the bridge are calculated when a CRH2 high-speed train running through the bridge, and the influence of bridge vibration on the running safety indices of the train, including derailment factors, offload factors and lateral wheel/rail forces, are analyzed. The results demonstrate that under the vessel collision load, the dynamic responses of the bridge are greatly enlarged, threatening the running safety of high-speed train on the bridge, which is affected by both the collision intensity and the train speed.

• 수산해양기술연구
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• 제41권1호
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• pp.64-69
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• 2005

In spite of many efforts, in the design of high speed fishing vessel the sea-keeping performance improvement without neglection of resistance-propulsion performance by hull form itself has its limitations. In this paper, the development of sea-keeping improving appendage pitching and trim improver for high speed planing hull on behalf of the hull form of fishing vessel has been introduced. The developed appendage verified its effectiveness in the full scale test and also has been proved the better resistance performance in the model test and full scale test.

• 수산해양기술연구
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• 제38권4호
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• pp.289-292
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• 2002

TPI는 고속 활주선의 소음, 진동, 트림 및 핏칭운동을 감소시킨 것으로 실선 시운전에서 증명되었다. 또한 모형시험에서 저항성능도 미소하게나마 개선시킨 것으로 입증되었다

• 대한조선학회논문집
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• 제48권4호
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• pp.357-362
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• 2011

It has been often reported that a water-jet propelled high speed vessel lost the course keeping ability in seaway. In this study, model tests of a high speed vessel were performed to measure the running attitude and to check the course keeping ability. The model ship may lose the course keeping ability due to bad running attitudes such as bow drop. So model tests were carried out to improve the running attitude by changing the position of longitudinal center of gravity and using appendages at the bow and the stern of a model. The position of lateral center of pressure moved toward stern and the course keeping ability was improved by modifying the transom wedge angle.

• 한국가구학회지
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• 제28권3호
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• pp.248-258
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• 2017

A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Thuja orientalis L., diffuse-porous wood Gmelina arborea Roxb., and ring-porous wood Phellodendron amurense Rupr., Longitudinal flow was considered from bottom to top while the radial flow was considered from bark to pith directions. In radial direction, ray cells and in longitudinal direction tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents(MC). The variation of penetration speed for different species was observed and the reasons behind for this variation were explored. The highest radial penetration depth was found in ray parenchyma of T. orientalis but the lowest one was found in ray parenchyma of P. amurense. The average liquid penetration depth in longitudinal trachied of T. orientalis was found the highest among all the other cells. The penetration depth in fiber of G. arborea was found the lowest among the other longitudinal cells. It was found that cell dimension and also meniscus angle of safranine solution with cell walls were the prime factors for the variation of liquid flow speed in wood. Vessel was found to facilitate prime role in longitudinal penetration for hardwood species. The penetration depth in vessel of G. arborea was found highest among all vessels. Anatomical features like ray parenchyma cell length and diameter, end-wall pits number were found also responsible fluid flow differences. Initially liquid penetration speed was high and the nit gradually decreased in an uneven rate. Liquid flow was captured via video and the penetration depths in those cells were measured. It was found that even in presence of abundant rays in hardwood species, penetration depth of liquid in radial direction of softwood species was found high. Herein the ray length, lumen area, end wall pit diameter determined the radial permeability. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Following a go-stop-go cycle, the penetration speed of a liquid decreased over time.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 추계학술발표회
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• pp.123-126
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• 2003

In the present paper, the analysis is on the safe navigation between ships moving each other in restricted waterways under the external force, such as wind or current The numerical simulation of manoeuvring motion was carried out to propose an appropriate safe speed and distance between ships, which is required to avoid marine disasters from the viewpoint of marine safety. From the inspection q this investigation, it indicates the following result In case of proximal navigation between ships under the wind and current, the low-speed vessel is potentially hazardous because the rudder force if low-speed vessel needed for steady-state course-keeping is not sufficient, compared to the high-speed vessel The manoeuvring characteristic based on this investigation will be very useful for keeping the safety of navigation from the practical point of ships design and traffic control in restricted waterways.

• 한국항해학회지
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• 제1권1호
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• pp.45-62
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• 1977

The advanced researches of the ship's motion in the seaway can predict the heaving, pitching and slamming of ship's motion. The researches as of today are that of displacement type such as a small typical fishing boat and U, UV and V bow ship forms under low speed. In recent day, the study of behaviours of high speed planning boat in the regular waves has been carried out by Bessho [5]. The calculation about behaviours of a high speed vessel in the longitudinal regular waves is calculated by Ordinary Strip Method in this paper. The data of the results were discussed and compared with Bessho's results. The conclusions deduced from this study are as follow, (1) The acceleration of motion calculated by the O.S.M. is similar with Bessho's data for the Fn 0.5 (2) The amplitudes of the behaviours of motions take peak at 1.0<λ/L<1.4.