• 대한조선학회지
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• 제7권1호
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• pp.57-78
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• 1970

The Korea inshore fishing boats are the size up to 30G.T., and their construction commonly employs the traditional wide wooden planking. Nevertheless, the hull forms have been developed with chine-type straight-framed sections which give developable surface party, but not on the whole: especially not on the whole portion of the hull are preferable for them. Considering many merits in the boat construction, the author, excluding cases of the FRP construction by hand lay-up or spray-up method and of the ferro-cement construction, finds out no reasons to depart from the chine-type hull forms of a developable surface in future development of their hull forms, too. In this report, the author proposed new designs of the developable hull surface for four typical boats forming the main structure of Korean inshore fishing fleets; 5G.T.-class multi-purpose boat, 10G.T.-class angling and longlining boat, 20G.T.-class drift and gill netters, and 27G.T.-class stow netters, and presented the tank test results on their propulsion resistance. The tank test had two purposes; one is to present the powering schedule of the new designs and the other to investigate the resistance characteristics of this kinds of boat in comparision with those of equivalent round-type boats at operational speed ranges. Between the both types of the boat no material differences in powering are expected. Hence, the author is confident of that saving in the construction cost of the developable hull over that of the round-type boat may result in considerable contribution to the over-all boat economy.

• 한국항해학회지
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• 제22권1호
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• pp.79-89
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• 1998

When an automatic course-keeping is concerned , as is quite popular in modern navigation, the closed-loop steering system consists of autopilot device, power unit(or telemotor unit), steering gear, magnetic or gyro compass and ship dynamics. In order to estimate steering system of ship in open seas, we need to know the characteristics of each component of the system and also to know the characteristics of disturbance to ship dynamics. Calculation methods of irrgular disturbances are based on the linear superposition principle. In this paper, for the purpose of evaluation of automatic steering of ships , the influences of linear control constants of autopilot on propulsive energy loss are investigated bya performance index is introduced from the viewpoint of energy saving. Numberical calculations are carried out for an are carrier and for a fishing boat in multi-directional waves.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2003년도 춘계학술대회 논문집
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• pp.215-220
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• 2003

최근 우리나라 연안어업은 한 일, 한 중어업협정, WTO 가입 등으로 주변 환경이 급격하게 변화되는 한편, 연근해 어자원의 감소와 근해어업과의 경쟁조업 등으로 인해 경영수지가 극도로 악화되고 있다. 이에 따라 정부에서는 연안어업의 경영수지 개선을 목적으로 1척의 선박으로 3개 이하의 업종을 허가하여 여기에 맞추어 선택조업이 가긍하도록 하였다. 하지만 기존선박은 단일업종을 대상으로 한 전용선반으로 건조되어 업종변경시 개조비용 발생은 물론 이거니와 개조에 따른 조업중단 또는 차질로 제 효과를 얻지 못하고 있는 실정이다. 그리고, 조선공학적 제 성능에 관한 면밀한 검토가 부족한 가운데 개조 사용함으로써 안정성을 저해하거나 조업효율이 오히려 떨어져 복수조업요건을 모두 수용할 수 있는 새로운 선형개발이 요구되고 있다. 이에 본 논문에서는 동해역 2톤급 다목적어선을 대상으로 하여 어선세력, 어민요구사항 및 어로시스템 분석 등을 통해 다목적어선 대상업종을 선정하고, 선정된 업종의 어로장비를 동시탑재 또는 부분 교체하여 조업할 수 있는 선형을 개발함으로써 연안 어민의 선박건조비 절감, 업종 교체에 따른 부대 경비경감과 안전도 저해요인 해소에 기여하고자 한다.

• 한국해양공학회지
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• 제33권3호
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• pp.289-299
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• 2019

Various sizes of ROVs are being utilized in offshore industrial, scientific, and military applications all around the world. Because of innovative developments in science and technology, image acquisition devices such as sonar devices and cameras have been reduced in size and their performance has been improved. Thus, we can expect better accuracy and higher resolution even in the case of exploration using a small ROV. The purpose of this paper is to prepare a standard procedure for the identification of unidentified hazardous materials found during the National Oceanographic Survey. In this paper, we propose an IDEF (Integrated DEFinition) method modeling technique to identify unidentified targets using a small ROV. In accordance with the proposed procedure, an ROV survey was carried out on target No.16 with a four-ton-class fishing boat as a support vessel on September 18th of 2018 in the sea near Daebu Island. Unidentified targets, which were not known by the multi-beam data obtained from the ship, could be identified as concrete pipes by analyzing the HD camera and high-resolution sonar images acquired by the ROV. The whole proposed procedure could be verified, and the survey with the small ROV required about 10 days to identify the target in one place.