• 한국해양공학회지
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• 제26권4호
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• pp.15-22
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• 2012

In this research, the relationship between the bow shape and green water phenomenon on the bow deck of an FPSO was studied using an experimental method. A 140,000 DWT FPSO was used as the objective hull form in the present research. The incident waves were regular types. The heights were 1.0 and 1.5 times the freeboard, and the length was equal in size to LBP. The wave heights and pressures on the deck were measured in experiments. Model tests were performed to determine the effects of bow flare angles, bow shapes, and a forecastle deck. The free heave and pitch conditions were applied to the models in these experiments. From the results of the model tests, an optimized bow shape was designed, which was found to decrease the green water impact loading. The results of this research could be used as fundamental data in the design of a bow shape.

• 수산해양기술연구
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• 제35권1호
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• pp.11-18
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• 1999

In order to secure accuracy and effectiveness of the electromagnetic compass as information sensor for ship's head up bearing with gyro compass, magnetic compass and electromagnetic compass on the sea and on the dock in land.The results obtained were as follows;1. Between the Northeast and the southsouthwest the deviation on ship's head up bearing on electromagnetic compass got easterly deviation with max. $53^{\cire}$on the East and between the Southwest and the Northnortheast westerly deviation with max. $34^{\cire}$ on the Northwest, of which values were not able to be corrected due to the angle excess of deviation adjustment.2. The varies of deviation seemed to have a tendency to increase easterly deviation on the Northeast and the East, easterly deviation after westerly deviation between the South and the Northwest, small one on the North and the Southeast.3. The varies of deviation of ship were larger than the one of around the dock, were extreme on the bow of forecastle deck and were stable on the ship's center line of compass deck at the dock in land.

• 대한조선학회논문집
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• 제52권3호
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• pp.255-264
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• 2015

Wind load and flow field of a drillship with respect to various super structures were experimentally investigated in KARI 1m-wide wind tunnel with an atmospheric boundary layer simulation. Six-component external balance and Particle image velocimetry technique were used to measure wind load and velocity vectors in the flow-field around the model respectively. The experimental model was an imaginary shaped drillship with an approximated model which has 1/640 scale compared with recent typical drillships. The test Reynolds number based on the overall length was about 1.5×10⁶. It was found that dominant factors influencing on ship wind load are cabin shape and cabin height. Round cabin has smaller axial wind load and narrow boundary layer around the ship than rectangular one, but its yawing moment at certain angles becomes higher. Low cabin height also show positive effects on axial wind load too. Hull shape and forecastle shape show relatively small influences on wind loads except for slight changes around ±45° wind directions.

• 한국정보통신학회논문지
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• 제2권3호
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• pp.359-365
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• 1998

The portable two way radio telephone amongst GMDSS equipment in the vessel is very important portable wireless one for search and rescue in distress situation. Although the portable two way radio telephone must be equipped with in the vessel by IMO & RR, other kinds of wireless tranceivers are widely used to communicate with crew members who are separately appointed at bridge forecastle and poop in leaving or arriving at the port, passing through a narrow canal or voyaging in the foggy weather, Most of those wireless tranceivers except portable two way radio telephone are allocated at 27MHz band with PTT simplex system that makes crew members difficult to work effectively in the vessel. In this research 900MHz band FDD(frequency duplex division) tranceiver system is studied to help crew members in the vessel to communicate with themselves freely and to work easily meanwhile with simple operation. 900MHz band FDD tranceiver system uses one chip FM frontend IC to realize the miniaturization and downsizing of tranceiver and small size head set attached to helmet. The credibility of this research's result is highly evaluated by circuit analysis with computer aided simulation, and partly modified 900MHz band cordless phone circuit.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1998년도 춘계종합학술대회
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• pp.365-370
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• 1998

The portable two way radio telephone amongst GMDSS equipment in the vessel is very important portable wireless one for search and rescue in distress situation. Although the portable two way radio telephone must be equipped with in the vessel by IMO RR, other kinds of wireless tranceivers are widely used to communicate with crew members who are separately appointed at bridge forecastle and poop in leaving or arriving at the port, passing through a narrow canal or voyaging in the foggy weather. Most of those wireless tranceivers except portable two way radio telephone are allocated at 27MHz band with PTT simplex system that makes crew members difficult to work effectively in the vessel. In this research 900MHz band FDD(frequency duplex division) tranceiver system is studied to help crew members in the vessel to communicate with themselves freely and to work easily meanwhile with simple operation. 900MHz band FDD tranceiver system uses one chip FM frontend IC to realize the miniaturization and downsizing of tranceiver and small size head set attached to helmet. The credibility of this research's result is highly evaluated by circuit analysis with computer aided simulation. and partly modified 900MHz band cordless phone circuit.

• 해양환경안전학회지
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• 제3권1호
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• pp.33-49
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• 1997

One of the most important missons that are imposed on merchant ship at sea is to accomplish the safe transportation of cargo loaded. Recently, a study on the seakeeping performance has been carried out on the development of evaluation system related to the synthetic safety of a ship at sea. The seakeeping performance is the ship's ability sailing at, and executing its misson against adverse environmental factors successfully and safely. Until now, however, there has not been any method of quantitative evaluation on the dynamic safety of the ship's cargo loaded. In this regards, this paper has introduced the evaluation method of dynamic safety of the ship's cargo. In order to evaluate the dynamic safety of cargo, the vertical and lateral acceleration which causes the collapse, racking and local structure failure of cargo was adopted as the evaluation factors in the ship's motions. The response amplitude of ship's motions in regular waves is manipulated by NSM (New Strip Method) on a given 2,700 TEU full container vessel under the wind forces of 7, 8 and 9 Beaufort scale. Each response of ship's motions induced by NSM was applied to short-crested irregular waves for stochastic process on evaluation factors and then vertical and lateral acceleration of each cargo was compared with significant amplitude of each acceleration. A representative dangerous factor was determined by comparing permissible values of stacking and racking forces occurred typically to the vertical and transverse directions with the container strength required on ISO 1496 at the positions of forecastle, poop and ship's midship respectively. Through the occurrence probability of the determined factor by Rayleigh's probability density function, the dangerousness which limits loads on container's side wall as an evaluation was applied in judging of the danger of the ship's cargo loaded.

• 수산해양기술연구
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• 제40권1호
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• pp.54-59
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• 2004

최근 개발되고 있는 전자자기 컴퍼스를 이용한 소형어선의 항행자동화시스템을 구축하기 위한 기초 연구로서, 부두에 계류된 선박에서 각종 장비의 가동 시켰을 때 나타나는 컴퍼스 오차 변화를 측정하여 비교 분석한 결과를 요약하면 다음과 같다. 1. 목선에서 85kW의 집어등을 점등하였을 때, 조타용 자기컴퍼스는 7$^{\circ}$편서되었고, 전자자기 컴퍼스는 13$^{\circ}$~16$^{\circ}$ 까지 편서되는 것으로 나타났다. 2. FRP 어선에서 13OkW의 집어등을 점등하였을때, 전자자기 컴퍼스는 19$^{\circ}$~23$^{\circ}$ 까지 편동되는 것으로 나타났다. 3. 강선에서 225kW의 전력으로 각종 장비를 가동 시킬 때, 가동전과 비교하여 컴퍼스 오차의 차분은 조타용 자기 컴퍼스에서는 13$^{\circ}$ 편서되고, 전자자기 컴퍼스는 상갑판에서는 68$^{\circ}$ 편서되었고, 선수루 갑판과 조타실 및 컴퍼스갑판에서는 각각 16$^{\circ}$, 32$^{\circ}$, 20$^{\circ}$ 편동되어 나타났다. 4. 소형어선의 항행자동화시스템에 전자자기 컴퍼스를 활용하기 위해서는 선박내에서 사용하는 각종 장비에 의해 발생하는 컴퍼스 오차를 측정하여 적절하게 수정하여 사용해야 할 것으로 판단된다.