• 해양환경안전학회지
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• 제24권6호
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• pp.694-700
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• 2018

우리나라는 원자력 발전소를 운영하면서 발생하는 중 저준위 방폐물을 경북 경주시에 위치한 방폐물처분장을 통하여 영구적으로 처분하고 있다. 하지만 방폐물의 해상운송은 해양사고의 위험성에 노출되어 있고, 이에 관하여 해양경찰의 기능과 역할적 관점에서 안전성 확보를 위한 제도의 도입이 필요할 것이다. 특히 우리나라는 허베이스프리트 사고 또는 세월호 사고 등 국가적 재난에 해당하는 대형 해양사고로 인하여 사회적 영향을 받은 바 있으므로, 이를 대비한 대응체계가 필요할 것이다. 이러한 관점에서 우리나라의 방폐물 해상운송의 현황을 파악해 보고, 외국 주요국의 대응체계에 대해서 살펴보았다. 주요 사고 사례를 검토한 결과, 이와 유사한 핵물질 운반선 및 위험물 운반선의 사고 등 사회적, 지역적, 국제적 영향을 미칠 수 있는 해양사고에 긴급하게 대응하고자 유럽 국가를 중심으로 비상예인선(ETV) 선단을 운용하고 있었으며 일정 부분 효과를 증명하고 있다. 이를 바탕으로 한국형 ETV의 도입을 제시한다. 즉, 핵물질 운송선박, 대형 유조선, 대형 여객선 등의 해양사고와 같이 막대한 환경적, 재산적, 인명적 손해로 이어질 수 있는 대형 해양사고의 초기 대응을 위해 비상예인기능, 유류오염 방제기능과 구조 장비 및 인력 수송이 가능한 한국형 ETV의 도입이 필요하리라 보인다. 이를 통해 해양경찰의 해양사고 대응기능의 향상으로 이어지며, 국가적 재난에 대한 초기대응의 골든타임을 놓치지 않게 되어 귀중한 인명과 재산을 지키고 환경을 보호하는데 일조할 것이다.

• 대한조선학회논문집
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• 제51권3호
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• pp.231-238
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• 2014

In this study, the self-propulsion tests are performed in INHA towing tank. And the effective wake characteristics of the KVLCC2 and the KCS models are compared by the experimental results. The form factor is independent of Reynolds number. To estimate the hydrodynamic performance of a full scale ship, the form factor is determined to consider attendant on Reynolds number. In this research, the power predictions are carried out considering the form factor difference of model and full scale ship. The results of this research could be used as one of the fundamental data to the powering performance prediction.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.222-227
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• 2000

"Side scan sonar" using acoustic signal has been developed to survey cable laying, sunken bodie\ulcorner bottom and so on. It use the acoustic signals, which are emitted from two transducer arrays, to get gemetri\ulcorner target area. This system consists of transceiver board, towed body, and deck unit. The transceiver board, w\ulcorner watertight canister of the towed body, controls the transmitting and receiving of 400kHz acoustic signals from \ulcorner After receiving the scattered signals, it processes the filtering, AGF(Automatic Gain Control), TVG(Time Heterodyne. The deck unit is composed of the signal processing part, A/D converter, power supplier, and real\ulcorner And the towed body has been designed to satisfy the optimal hydrodynamic behavior during towing. The de\ulcorner theory of transceiving part and some results from field-experiments will be introduced here.

• 수산해양기술연구
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• 제59권2호
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• pp.135-144
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• 2023

In order to provide basic data to increase the efficiency and stability of seamanship at anchoring, the characteristics of the hull motion including dragging anchor due to external forces were observed at Mokpo and Jinhae anchorage for the avoidance of the typhoon. As a result, it is necessary to check the embedding motion and holding power of the anchor according to at initial position to decrease dragging anchor. Dragging anchor at anchorage seems to have been easily caused according to discrepancy between embedded anchor flukes and the towing direction due to the change in wind direction, rather than the wind speed. This discrepancy, thus, should be considered when anchoring. This test vessel with a small radius of curvature of the stem is relatively vulnerable to the influence of wind direction and wind speed, so it is easy to cause a decrease in the holding power due to an increase in the rate of turn. When the current speed is greater than or equal to 1 knot, the range of the rate of turn is reduced resulting in a relatively increased holding power. In addition, during the swing, the tension of the chain was high according to the angular velocity change of heading at three-quarters of the swing length rather than the left and right ends.

• 해양환경안전학회지
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• 제18권6호
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• pp.597-603
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• 2012

해상에서의 안전한 예인 업무를 수행하기 위해서는 정확한 예인력의 추정이 필요하며, 이를 위해서는 예선의 저항성능 특성에 대하여 정확히 파악해 두어야 할 필요가 있다. 본 연구에서는 먼저 정수중 예선 주위의 유동 특성 및 예선의 저항추진 성능을 파악하고자 회류수조에서 예선 모형을 이용하여 실험을 실시하였다. 모형실험은 무한수심 조건에서의 1/33.75 축척으로 제작된 예선 모형을 이용하였으며, 설계속도를 7노트로 선정하고 역조와 순조의 조류 영향을 고려하여 5~10노트의 속도 구간에서 각 속도별로 실행하였다. 또한 파랑에 의한 예선의 운동응답 함수와 부가저항을 추정하기 위하여 수치계산을 실행하였으며, 이에 대한 결과를 정수중에서의 실험을 통하여 얻게 된 데이터와 비교하였다. 이와 같은 해석 결과 파랑중 부가저항은 선수파 및 속도가 높아질수록 증가하며, 유효마력은 정수중에 비하여 70 % 정도 증가하고 있는 현상을 확인할 수 있었다.

• 수산해양기술연구
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• 제32권1호
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• pp.7-15
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• 1996

Full scale experiment was carried out in the southern sea of Korea to compare some important factors tested in the model experiment. The results obtained can be summarized as follows ; 1. The changing aspect of mouth performance of the full scale net was almost coincided with the results obtained by the model experiment. The vertical opening(H) and the opening area(S) can be expressed as a function of the towing velocity(V) as H=48.78. $e^0.38V$(unit: m, k't) S= 1,443 .$e^-0.25V$(unit: $m^2V$, k't) 2. The changing aspect of working depth of the full scale net was almost coincided with the results obtained by the model experiment. The depth(D) can be expressed as a function of the towing velocity(V) and the warp length(L) as D=92.49.$V^1.37$(unit: m, k't, L= 150m) D= 12.07+0.32. L (unit: m, V=2k't) [)= - 7.90+0.22 . L (unit: m, V=3k't) 3. Some problems were found to operate A - type full scale net by common bottom pair trawlers. The problems can be summarized as follows; (1) Entangling of wing and square head ropes while net casting.(2) Man power needed and time spent for net hauling by common bottom trawlers increased considerably.( 3) Tearing of nettings caused by over -load of tension and entangling of net pendant while net hauling. To solve these problems, the trawlers are favorable to be equipped with variable pitch propeller and llet drum. While the net is favorable to be constructed with trifurcated net pendant in stead of quadrifurcated net pendant used at present.

• Journal of Advanced Marine Engineering and Technology
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• 제41권4호
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• pp.316-322
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• 2017

본 논문의 주 목적은 수치해석 도구를 활용하여 저항성능 관점에서 우수한 선형을 개발하는 것이다. 최종 개발된 선형의 성능 평가를 위해 수조 모형시험을 수행하였다. 현존선은 도면을 바탕으로 실물과 도면의 타당성 검토를 위해 실태조사를 수행하였다. 실태조사 시에 실제 운항 상태인 주 운항 배수량 및 주 운항 선속을 확인하였다. 수치해석을 바탕으로 현존선의 저항성능을 검토하였다. 개발선은 선수어깨의 파형개선, 배수량 분포의 균형화, 단면형상의 수정 그리고 중앙 스케그의 크기와 형상 변경에 관한 스터디를 통해 도출되었다. 수치해석 결과 개발선은 조파저항 개선에 의해 저항성능 관점에서 주 운항 선속인 11노트에서 약 15% 개선된 양을 보여주었다(Table 4 참조). 개발된 선형의 성능 평가를 위해서 수조 모형시험을 수행하였으며 그 결과 11노트에서 약 17% 개선된 양을 보여주었다(Table 5 참조).

• 수산해양기술연구
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• 제53권4호
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• pp.446-455
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• 2017

The improvement of resistance performance for the 4.99 ton class fishing boats was shown. The 4.99 ton fishing boats are the most commonly used one in the Korean coastal region. The evaluation of resistance performance was estimated by the Computational Fluid Dynamics (CFD) analysis. The CFD simulation was performed by the validation for various types of bow shapes on the hull. The optimized hull form from the simulation was selected and showed the best resistance performance. This hull type was tested on the towing tank in the National Institute of Fisheries Science (NIFS). The effective horsepower (EHP) was estimated by the resistance test on the towing tank with the bare hull condition. The drag force on the three service speed conditions was obtained for the resistance analysis to power prediction. The measured drag forces are compared with the results from the CFD simulation with one another. As results of the model tests, it was confirmed that the shape of the bow is an important factor in the resistance performance. The effective horsepower decreased about 30% in comparison with the conventional hull form. Also, the resistance performance improved the reduction of required horsepower, which especially contributed to the energy-saving for the fisheries industry. In the CFD analysis, the resistance performance improved slightly. In this case, the ratio of the residual resistance ($C_R$) in the total resistance ($C_T$) was high. Therefore, the CFD analysis was not enough to satisfy with reflection for the free surface and wave form in the CFD procedure. Both model test and CFD calculation in this study can be applied to the initial design process for the coastal fishing vessel.

• 수산해양기술연구
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• 제54권1호
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• pp.12-24
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• 2018

This study was conducted in order to improve opening efficiency of the miniaturized large-scale net for anchovy boat seine gear to reduce the fleet size. Field experiments were performed to observe geometry of nets by catcher boats. When the distances between the two ships were 150, 300 and 450 m, and the speeds of towing nets were 0.6, 0.9, and 1.2 k't, respectively. The vertical opening and actual opening of each part of the miniaturized large-scale net was as follows: the front part of the wing net, 8.7-13.3 m, 51-78%; the middle part of the wing net, 28.1-34.2 m, 55-67%; the entrance of the inside wing net, 31.3-38.5 m, 60-73%; the square and bosom, 22.7-29.6 m, 47-62%; the entrance of the body net, 20.9-26.4 m, 42-52%; the entrance of the bag net, 17.2-21 m, 72-89%; the flapper, 13.2-15.3 m, 78-83%; and the end of the bag net, 13.2-15.7 m, 72-75%. By connecting the net pendants with the front part of the wing net, the opening of the front part of the wing net was significantly improved compared to the traditional gear, which ensured both the wing net and the inside wing net with a normal net height. This, in turn, increased the efficiency of herding. The height of the body and bag nets was also higher than that of the tradition gear. In particular, the body net attached to the gear significantly improved the pocket shape of the gear and reduced the number of fish that were caught and escaped from the bag net, which increased the rate of fishing. The tension of towing nets was measured approximately between 2,958 and 7,110 kg, which indicates that the fleet can tow nets with 350 ps, the standard engine horse power. The fishing operation time was shortened compared with of the existent net, and the large-scale buoy attachment operation was also possible to operate the ship without fish detecting boat.

• 수산해양기술연구
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• 제55권1호
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• pp.7-19
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• 2019

This study was conducted in order to improve opening efficiency of the miniaturized small-scale net for anchovy boat seine gear to reduce the fleet size. Field experiment was performed to observe geometry of nets by catcher boats. When the distance between the two ships was 150, 300 and 450 m and the speed of towing nets was 0.6, 0.9, and 1.2 kt, the vertical opening and actual opening of each part of the miniaturized small-scale net was as follows: the front part of the wing net, 6.8-9.5 m, 45-63%; the middle part of the wing net, 16.1-30.7 m, 34-65%; the entrance of the inside wing net, 21.6-41.2 m, 44-84%; the square and bosom, 17.4-34.0 m, 38-75%; the entrance of the body net, 16.5-29.4 m, 36-64%; the entrance of the bag net, 14.5-21.9 m, 70-106%; the flapper, 6.7-7.7 m, 81-83%, and the end of the bag net, 8.6-10.9 m, 64-81%. The tension of towing nets was measured to be 2,734-6,812 kg approximately, which indicates that the fleet can tow nets with 350 hp, the standard engine horse power. The fishing operation time was shortened comparing to existent net with the large-scale buoy attachment operation. It was also possible to operate the ship without fish detecting boat.