• 대한조선학회논문집
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• 제41권1호
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• pp.40-46
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• 2004

In this paper, one of the harbour manoeuvring tests is described. its goal is to investigate the so-called crabbing performance of ships. By crabbing is meant the ability of the vessel to move sideways with the use of her own manoeuvring devices like propellers, rudders, transverse thruster, etc. The crabbing model tests were carried out in the Ocean Engineering Wide Tank, University of Ulsan(UOU) to measure the transverse forces and yawing moments by the transverse thruster alone and the propeller-rudder arrangement in combination with the bow thruster. The comparison between UOU crabbing test results and data measured at one of foreign research institutes showed a little gap due to different rotating conditions of controllable pitch propellers.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권3호
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• pp.294-306
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• 2018

Most offshore structures including offshore wind turbines, ships, etc. suffer from the impulsive pressure loads due to slamming phenomena in rough waves. The effects of elasticity & plasticity on such slamming loads are investigated through wet free drop test results of several steel unstiffened flat bottom bodies in the rectangular water tank. Also, their cumulative deformations by consecutively repetitive free drops from 1000 mm to 2000 mm in height are measured.

• 한국기계가공학회지
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• 제6권1호
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• pp.13-19
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• 2007

The spring is an important mechanical parts to improve the functions of precision machines, automobiles, ships, industrial machines, and IT devices etc.. The hinge mechanism for LCD monitors is very important to support and maintain the proper position of monitor panel, and the tension spring which is a major parts of hinge mechanism plays a significant roll to provide the supporting force positioning the monitor panel. In this paper, an analysis and experiment were carried out to investigate the fatigue characteristics of the tension spring of hinge mechanism, such as hardness test, fatigue test and fractography analysis. As a result of this study the SWPB with heat treatment and shot peening was found to have the optimal design conditions of tension spring for LCD monitor hinge mechanism.

• 대한조선학회논문집
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• 제29권3호
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• pp.102-116
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• 1992

하나 또는 두개의 지주를 가지는 소수선면 쌍동선의 유체동역학적 특성에 대한 비교 연구결과를 다루었다. 두 모형선으로 정수중에서의 저항, 파랑중에서 정지 및 속도를 가질 때의 6자유도 운동응답, 그리고 파랑하중 등을 수조 실험실에서 측정하였으며 수치해석결과들과 자세하게 비교하였다. 본 연구 결과에 의거하여 두 SWATH 모델들의 장단점을 열거하였으며 이는 SWATH선의 설계 고려에 유익하게 쓰여질 수 있다고 생각된다.

• 대한산업공학회지
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• 제35권1호
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• pp.92-100
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• 2009

Today international trade through maritime transportation is significantly increasing. Due to this increase, shipping companies are faced with problems concerning the repositioning of empty containers from import dominant ports. The liner shipping service network has been provided to transport containers which load customers' freights. Container ships are moved on the liner shipping service network by observing the predetermined route and transportation time. This research deals with the empty containers distribution problem considering the container ship route. A mathematical model based on the mixed integer program has been introduced in this study. The objective is to minimize the total relevant costs of empty containers such as handling, leasing, and inventory holding, etc. Due to the complexity of the problem, a genetic algorithm has been suggested to solve large sized problems within a reasonable time. Numerical experiments have been conducted to show the efficiency of the genetic algorithm.

• Journal of Advanced Marine Engineering and Technology
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• 제28권8호
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• pp.1286-1290
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• 2004

This paper describes the anti-corrosion system on underwater structures of ships. Metals and alloys have several positions in the series such as immunity, corrosion and passivity. The iron potential has to change from the corrosion position to the anodic protection or cathodic protection for preventing corrosion by providing corrosion protection system such as ICCP(Impressed Current Cathodic Protection). The purpose of ICCP system is to eliminate the rusting or corrosion, which occurs on metal immersed in water. The system includes a power supply unit, which consists of a transformer, a converter. a controller, etc. This paper presents the protection performance of ICCP under dynamic condition such as velocity. The variation of potential and current density with time and environment factors are also described Finally, the experimental results will be explained and analysed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.171-175
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• 2006

Recently, two reverberation rooms were built up of 300mm thick concrete walls in non-parallel pentagonal shape to measure the sound absorption, transmission, radiation, and impact insulation of acoustical materials, panels, doors, etc. Various acoustic tests, including the sound transmission test, were carried out to investigate their acoustic performances. In order to improve the performance, several modifications on these acoustical parameters, such as the acoustic mode, the position of specimen, the formation of diffuse field, the location of sound source, and flanking transmission, have been conducted. Through a series of tests, the reverberation rooms have been effectively improved so that it could perform a variety of acoustic tests with the international standard. And then, it is expected to be very helpful in developing the low noise design technology for ships.

• 한국항해학회지
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• 제16권3호
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• pp.55-64
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• 1992

Officers and ratings as a group might show differences in some aspects of personality , human relations, job attitudes, perception of business environment and surrounding organizational structure. It has been traditionally believed that licenced-officers are required to have nicely-paired leadership and dignity , and ratings obedience in maritime field. This survey revealed that officers and ratings have some differences in the actual behavior, knowledge , understanding attitude etc., In summary , officers as a superstructure of merchant ship's orgnaization are different, to some degree, from ratings as an infrastructure in several aspects. Officers are believed to have the characteristics of maturity by taking concern of business environment , social circumstance away from the vessels which they are on board. In contrast, ratings are greatly interested in the surrounding environment associated with themselves, and also experiencing alienation and technology.

• 수산해양교육연구
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• 제29권2호
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• pp.415-421
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• 2017

This study is aiming to find one of working conditions for loading and unloading a large ship at game port. Firstly, for dynamic analysis of the moored ships, the motion characteristics of ship according to loading condition are figured out. The motion characteristics of ship is related to environmental factors such as current, wind, mooring line, fender and etc. As a result, it is ascertained through numerical simulation using the AQUA MARINE developed by ANSYS INC. This study might contribute to make a new method of mooring stability of target ship.

• 한국기계가공학회지
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• 제10권3호
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• pp.87-93
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• 2011

CNC lathe machining has been widely used for parts machining of vehicles, aircraft, ships, electronics, etc. because cost savings for shortening processing time and increasing productivity are great. In this study, the purpose is to investigate the effect of cooling methods such as oil mist, water-soluble cutting oils on the workpiece surface roughness with the cutting speed, cutting depth, tool nose radius and feed rate of CNC lathe machine as a parameter in the cutting process of the aluminum alloy 2024 which is used a lot recently on aircraft parts. It is found that oil mist is coolant and water-soluble cooled by cutting the experimental conditions, cutting speed and cutting depth without effecting the surface roughness value was constant.