• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.1
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• pp.30-37
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• 2002

Recently, there have been frequent environmental threats associated with the red tide. The discharge of bilge water and waste lubricating oil from fishing vessels is known to be the major cause of such problems. In oder to treat those wastes, post processing units at harbours are being considered, and an accurate prediction of the amount of such wastes is required. In this paper we have proposed a method to estimate the amount of bilge water and waste lubricating oil from fishing vessels. We identified the key parameters affecting the quantity of oily bilge water and waste lubricating oil, and proposed a prediction model. We applied the present model to estimate the quantity of oily bilge water and waste lubricating oil in the sample fishing port.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.130-138
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• 1994

Bottom plates of empty hold are subjected to not only water pressure but also bi-axial inplane loads, specially in the alternate full loading full loading condition of bulk carrier. This kind of plate behaviours is very difficult to be explained and to be estimated using common buckling design guide in the initial design stage of hull structure, therefore, some more concrete studies for this plate structure was performed based on the currently developed buckling estimation formula. In this buckling formula, torsional stiffness effects of edge stiffener are included additionally and effects of elastic buckling strength of plate panel are treated as characteristic value problem. Also considering boundary stiffener effects and inplane and lateral loading, evaluation of bottom plate scantling using this formula, calculated results using various classification regulation of buckling strength and results of first report approach are compared each other and useful guides using developed formula for bottom plate scantling design are discussed.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.1-7
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• 1999

This paper describes the modification of hull bottom for the air lubrication technique to the passenger boat in service at the Chung-Ju lake, which has a large beam-draft ratio. From numerical analysis of 2-D cavity problem by potential theory, the cavity shape, length and the pressure in cavity are estimated for the simplified geometry of hull bottom, and the non-dimensional parameters affecting air cavity phenomena are investigated. Extensive resistance tests for the model ship which has variation of step height and side strip have been performed to investigate the formation of air cavity and the drag reduction effectiveness. And also, the development of attached cavity to the bottom were observed from the flat bottom made by transparent acrylic plate. From this survey on the modification of bottom shape and the air lubrication technique, the total resistance of model ship could be reduced by about 25% at the design speed compared to the proto type hull form.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.220-221
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• 2018

배스보트는 주로 민물에서 낚시를 위해 설계되는 소형 고속 활주형 선박으로 국내에서도 수요가 높은 편이다. 하지만 경기에 참가하는 선수들이 선호하는 17ft급 이상의 배스보트에 대해서는 수입에 100% 의존하는 중이다. 본 연구에서는 18.5ft급 배스보트의 주요요목 결정 및 선형을 개발하고, 선저경사각을 결정하기 위해 상용 CFD코드인 STAR-CCM+ v10.04를 사용하여 수치해석을 수행하여 각 선저경사각별 항주자세 및 저항성능을 분석하여 최적의 선저경사각을 갖는 선형을 도출하였다.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.157-162
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• 2012

A planing craft is designed specifically to achieve comparatively high speed on the surface of the water. The frictional resistance of planing craft can be reduced further by injecting air to the craft's bottom. In this paper, the resistance characteristics of high speed planing crafts with & without air injection at the bottom were compared by sea model-test method. As a result, we conformed that planing craft with air injection has much greater the effect of resistance reduction.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.583-588
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• 2008

The planing craft is designed specifically to achieve comparatively high speed on the surface of the water. In general, the stepped hull craft has effect improvement in speed and fuel-efficiency because of the reduction of total resistance by a small wetted surface area without corresponding stepped hull craft. In this paper, the high speed stepped hull crafts with respect to the number of bottom steps were performed to compare the effect of resistance performance using at-sea model-test method. In conclusion, the stepped hull craft with twin-step was proved to be effective to reduce the total resistance.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.1
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• pp.121-132
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• 1994

The aim of the present paper is to clarify the damage characteristics fur ship bottom stiffened platings in grounding. For this purpose, a series of tests are performed. A rigid wedge is quasi-statically pushed into the high tensile steel plates with two stiffeners. The aspect ratio of plates(a/B) is in the range from 1.0 to 2.5 and the thickness of plates is in the range from 3.4 to 7.0mm. Also other parameters, namely the shape of wedge tip, wedge angle and property/direction of stiffeners are varied. The test is carried out using the 100ton universal test machine. During the loading. both applied force and length of cutting(penetration) resulting in the grounding force-penetration response are measured.

• Journal of Advanced Navigation Technology
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• v.24 no.5
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• pp.343-347
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• 2020

This paper presents the development of a software for tracking the location of objects in the water and for creating a three-dimensional hull map. The objective of this software, as a software for underwater hull cleaning robot, is to map the location of underwater hull cleaning robot and to locate the position of sensor by identifying the shaded area of acoustic communication. For the software designed for mapping the location of cleaning robot in the water, the height and intensity were applied as variables for underwater ultrasonic communication. The software for creating a three-dimensional hull was developed by OpenGL using scanned lines from a blueprint of a ship. This software can help identifying the location of underwater hull cleaning robot without actual visibility and can be used to maintain a stable communication status by locating the position of sensor by easily spotting the shaded area of acoustic communication caused by the curved area of the bottom of the ship.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1593-1601
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• 2018

The International Hydrographic Organization has developed the S-100 standard as a geospatial standard to express various types of hydrographic information. Product specification describes information of data on ENC such as definition, structure, data model, etc. S-129 PS is for under keel clearance management information. In this paper, to help developers to implement S-129 PS using the technology of S-100, we analyze the process to portray the S-100 based data and then implement a case study. This paper introduces the XSLT processing of portrayal engine to reform the generated data set, and the generation of drawing instructions to display the data set on the electronic chart. A case study is experimented to display the portrayal output of under keel clearance management on an electronic chart.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.2
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• pp.96-104
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• 1984

This paper is on the prediction and response of the ship hull girder due to slamming of foreward flat bottom plate. The response with respect to foreward flat bottom is divided two kinds by estimating method. One is the estimation of impact forces by slamming, Another is the response of hull girder due to impact forces, that is, displacement, velocity, acceleration, etc. must calculate the values for considered ship hull girder. In this paper, therefore, was estimated only impact forces along ship ordinate of foreward. The analysis of data for estimation followed mainly papers of Ochi. These estimated data shall contribute for ship gull construction for basic optimum design. In particular, the estimated impact forces shall be given for the response of ship gull girder on the foreward flat bottom plate with characteristics of external forces.