• 한국수산과학회지
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• 제50권6호
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• pp.788-798
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• 2017

Antarctic krill Euphausia superba are important components of the Antarctic marine ecosystem both economically and ecologically; to manage this species effectively, their distribution and abundance must be understood. Using the Kwang Ja-Ho (3,012 tonnage), a commercial fishing vessel, we conducted acoustic surveys during April 13-24, 2016, to estimate the distribution and population size of krill around the South Shetland Islands of the Antarctic Continent, We used acoustic techniques based on the dB-difference, a method used mainly to classify of marine species. We found that Antarctic krill were present in numbers over 99% at six survey stations, with the exception of Station 3, where we only found Electrona carlsbergi. There was no difference in cell size due to frequency differences, but echo signals differed between species: 4.7-12.0 dB for Antarctic krill, and -4.1~0 dB for Electrona carlsbergi.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.81-85
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• 2003

어업통신에서 출어선의 위치보고를 디지털화하여 VMS(Vessel Monitering system)를 구축하기 위하여는 체계적인 정보의 관리와 운용이 필요하다. 또한 위치정보의 체계적인 관리를 위해서는 먼저 정보의 권역화 및 집중화가 선행되어야 한다. 지역의 전파환경, 출어선의 조업해역, 어선세력, 트래픽량 등을 고려하여 권역을 구분하고, 권역별로 선위정보를 수집하여 이것을 본부에 집중하면 VMS의 DB를 구현할 수 있다. 본 논문에서는 VMS를 구축하기 위한 어업정보망의 구축과 어선의 위치정보를 자동으로 전송하는 방안에 대하여 연구하였다.

• 한국수산과학회지
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• 제43권6호
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• pp.659-664
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• 2010

This study investigated the distribution of spotted seals, Phoca largha, inhabiting the coast of Baekryongdo. Monitoring of spotted seals in Baekryongdo was conducted between June 2006 and November 2008, using a 5-ton fishing vessel 1hour before low tide. The monthly maximum number of observed seals was 274 in September 2006, 139 in September 2007, and 213 in August 2008. Average observed monthly counts were largest in August and September. Relatively more spotted seals were observed when there were few cloudy days and plenty of sunshine. Bycatch, stranding, and observations of spotted seals have been reported along the coast of the Korean peninsula since 2000, and spotted seals were observed four times in the western coastal region, three times in the southeastern region, and 12 times on the east coast. This suggests that spotted seals inhabiting Baekryongdo migrate to the East Sea via the West and South seas as individuals or in groups.

• 한국소음진동공학회논문집
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• 제13권12호
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• pp.923-929
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• 2003

As for the marine propulsion shafting system using 4 stroke diesel engine, it is common to apply a reduction gear box between diesel engine and shafting to increase propulsion efficiency, which requires inevitably a certain elastic coupling to avoid chattering and hammering inside of gear box. In this study, the optimum method of rectifying propulsion shafting system in case of 750 ton fishing vessel is theoretically studied in a view of dynamic characteristics of torsion. After the replacement of diesel engine and gear box, the torsional vibration get worse and so some countermeasures are needed. The elastic coupling is modified from a present rubber coupling of block type having relatively high torsional stiffness to a rubber coupling haying two serially connected elements. Torsional vibration damper was installed at crankshaft free end additionally and moment of inertia of flywheel was adjusted. The dynamic characteristics of shafting system was improved by these modification. The theoretical analysis of torsional vibration are compared to measurement results using two laser torsion meters during the sea trial.

• 대한조선학회지
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• 제26권1호
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• pp.1-10
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• 1989

본 연구에서는 추파중에 항행하는 선박의 전복현상과 관련된 횡복원성 문제를 다루었다. 추파중에서 항행하는 선박의 복원력 변동량을 이론적으로 규명하기 위해서 Froude-Krylov 가설과 파랑중에서의 정적 평형조건 등을 이용한 이론계산법을 정식화하였다. 그리고 본 이론계산법에 따라서 고속화물선 선형과 어선 선형에 대해서 복원력 변동량을 계산하였으며, 동일한 파랑조건하에서 실시된 Hamamoto의 모형실험 결과와 비교하였다. 상기 이론계산 결과 및 모형실험 결과로부터 추파의 파정에서 선체중심이 위치하였을 때 복원력이 평수중에 비해서 절반이하로 감소되며, 이때 전복의 위험이 있다는 것을 확인할 수 있었다.

• 한국수산과학회지
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• 제49권6호
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• pp.856-861
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• 2016

This study compared the density of fish determined using three different echogram methods: the frequency-difference, time variable, and threshold modification methods. An acoustic survey was conducted off the coast of Jeju Island after sunset. Data at 38 and 120 kHz frequencies were collected using a commercial fishing vessel. As a reference point, the value of ${\Delta}MVBS_{120-38kHz}$ that distinguished fish from zooplankton using the 38 and 120 kHz frequencies was set at < 2 dB. The estimated density of fish along the survey line was 0.1-30.4, 0.1-64.3, and $0.1-51.7m^2/nmi^2$ using the frequency difference, time variable threshold, and threshold modification methods, respectively. The results of this study constitute basic research for estimating fish densities.

• 수산해양교육연구
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• 제29권2호
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• pp.396-408
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• 2017

This study aims to analyze pre-service elementary teachers' oceanographic literacy, understanding of ocean environmental problems and opinions on teaching strategies for ocean topics. As survey participants, this study selected 126 pre-service elementary teachers. Firstly, as a result of testing their oceanographic literacy, this study found out that out of all the basic principles, 'Oceans Largely Unexplored' was highest in the mean score, followed by 'Human Connections', 'Ocean & Its Life Shape Earth', 'Habitability', 'Biodiversity', 'Weather & Climate' and 'Size of Ocean'. Besides, regarding environmental problems affecting all the aspects of ocean, they mentioned oil spills caused by vessel accidents, so called 'Oil Pollution', as the most serious marine environmental problem. Regarding environmental problems affecting coral reefs, they considered over-fishing as the most serious problem. Secondly, as a result of analyzing their opinions on effective teaching strategies for ocean-related topics in elementary science textbooks, this study found out that regarding topics about understanding the undersea topography in the chapter of the earth and moon, they proposed 'Making an Undersea Topographic Model with Sand' most as an effective teaching strategy. As an effective teaching strategy for the chapter of animals' lives, they proposed 'Classifying Animals with Marine Animal Cards' most. As an effective teaching strategy for the chapter of ground surface changes, they proposed 'Making and Simulating Seashore Topography' most.

• 어선
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• 제29권
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• pp.15-20
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• 1986

This paper describes on the measurement of the deck vibration produced by the main engine vibration of stern trawler MIS SAE-BA-DA (2,275GT, 3,600PS) while the ship is cruising and drifting. The obtained results are as follows; 1. The deck vibration level was the highest point at vertical line which pass main engine and the lowest point at vertical line which pass top bridge while the crusing. 2. The vibration source level of the main engine, screw shaft and screw propeller were respectively 110, 90 and 80% while the crusing. 3. The main deck vibration pressure level at the check points 2, 20, 30, 40, 60, 70, 80, 86m from the bow to stern was respectively 9, 8, 7, 10, 22, 45, 18, 23%. 4. The frequency distributions of the main engine, screw shaft, screw propeller vibration were from 3Hz to 10KHz, predominant frequency was 1KHz, each vibration accelration the highest level were respectively 1.3, 0.8, 0.5mm/$S^2$. 5. The predominant frequency distributions of the main deck, second deck, bridge deck and top bridge deck's vibration were from 10 to 30Hz, and each vibration accelration level were respe¬ctively 0.7, 0.05, 0.07, 0.04mm/$S^2$.

• 한국정보통신학회논문지
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• 제7권7호
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• pp.1387-1392
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• 2003

어업통신에서 출어선의 위치보고를 디지털화하여 VMS(Vessel Monitoring system)를 구축하기 위하여는 체계적인 정보의 관리와 운용이 필요하다. 또한 위치정보의 체계적인 관리를 위해서는 먼저 정보의 권역화 및 집중화가 선행되어야 한다. 지역의 전파환경, 출어선의 조업해역, 어선세력, 트래픽량 등을 고려하여 권역을 구분하고, 권역별로 선위정보를 수집하여 이것을 본부에 집중하면 VMS의 DB를 구현할 수 있다. 본 논문에서는 VMS를 구축하기 위한 어업정보망의 구축과 어선의 위치정보를 자동으로 전송하는 방안에 대하여 연구하였다.

• 한국항만학회지
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• 제7권1호
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• pp.89-114
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• 1993

ICLL 66 is the most widely ratified instrument of the IMO and is, along with the International Convention on Safety of life at Sea (SOLAS), the primary document setting forth internationally agreed ship safety standards. ICLL 66 set freeboard requirement based on experience gained from the first Load Line Convention in 1930 and on contemporary developments in ship design. Reexamination of ICLL 66 is indicated by the proliferation of novel ship designs for which it lacks adequate regulations and by significant advancements in analytical seakeeping and deck wetness prediction techniques now available to the designer. In this paper, the Freeboard Advisory Group reviews these issues against the changing climate of the marine industry and maritime administrations, discusses the state of the art in analytical seakeeping programs, and outlines a series of recommendations for the establishment of a new international load line convention for the next century. The steps needs for an international program at IMO are discussed and a new convention is proposed.