• 한국해양공학회지
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• 제18권5호
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• pp.22-28
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• 2004

This study constructed a 3D real-time numerical model that predicts the water quality and movement characteristics of the inner bay, considering the characteristics of the wind-driven current and density current in estuaries, generated by the river discharge from the Hyeong-san river and oceanic water of the Eastern sea. The numerical model successfully calculated the seawater circulation current of Yeong-il Bay, using the input conditions oj the real-time tidal current, river discharge, and weather conditions during March 2001. This study also observed the wind-driven current and density current in estuaries that are effected by the seawater circulation pattern of the inner bay. We investigated and analyzed each impact factor, and its relationship to the water quality of Yeong-il bay.

• 생명과학회지
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• 제15권3호
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• pp.468-473
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• 2005

여수연안은 어류 치사성 유해적조생물인 C. polykrikoides 적조가 매년 발생되는 해역일 뿐만 아니라 섬진강으로부터 담수유입이 돌산을 중심으로 많은 영향을 받고 있다. 담수유입에 따른 염분도 변화가 C. polykrikoides의 수직이동에 영향을 미칠 수 있는 지를 조사했다. 실험장치는 60l들이 아크릴 수조에 일반해수와 담수와 해수를 혼합시킨 시험구를 설정하여 C.polykrikoides의 수직부상 속도와 DNA/RNA함량 비교를 하였다. 실험은 5일 동안 시행했다. 실험개시로부터 종료시까지 시험구의 경우 상층부위에서는 염분이 20으로 나타난 반면에, 하층은 30 정도로 유지되었다. 그러나 용존산소와 pH 변화는 시험구와 대조구 모두 비슷한 양상을 보였다. 또한 chlorophyll a도 수조의 하층보다 상층에 높은 수치를 보였다. 24시간동안 C. polykrikoides 상$\cdot$하층 이동을 조사한 결과 점등이 되는 순간 시험구는 대조구에 비하여 월등히 높은 상승을 보였으나, 시간이 경과함에 따라 그 차이는 적었다. 소등이 되는 동안은 점등에 비하여 상$\cdot$하층 현저한 차이를 볼 수 없고 대부분 균일하게 분포하는 양상을 보였다. 또한 실험 종료시나 24시간 주 $\cdot$야간 수직이동 시 대조구에 비하여 시험구에 분포하고 있는 C. polykrikoides의 DNA 및 RNA 변화폭이 높았다 이 실험을 통하여 담수유입은 C. polykrikoides 세포에 많은 영향을 미칠 수 있을 것으로 보이며, 특히 신속한 수직상승으로 인하여 여기에 대한 C. polykrikoides의 모니터링이 절실히 요구되는 바이다.

• 한국초등과학교육학회지:초등과학교육
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• 제36권1호
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• pp.1-15
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• 2017

The purpose of this study is to analyze the problems of land and sea breeze model experiment that has presented in $5^{th}$ grade curriculum in chapter "Weather and our lives" and makes better model simulation so that learners can have better and more effective way to study it. To survey the opinions from dedicated teachers about land and sea breeze model experiment, we produced the survey through interview with science exclusive teacher from M elementary school. An elementary science education expert, 3 men of science EdD modified and complemented survey and started Delphi survey to 12 science teachers who have career teaching more than 3 years. The problems found in this survey were 'one heat bulb, short heating time, small temperature difference of water and sand, lack of class time, empty space between sand and water, back of transparent boxes, little amount of scent and the location of the it' etc. But the most of all, it is hard to see the successful result of the experiment. Based on these kinds of investigations, and lots of trial and error, redesigned the new model experiment that has the most similarity to the real one and high probability of success. According to this, it was able to see the smoke forms horizontal movement along the sand and the smoke goes in one circulation cycle. through this experiment, we made a conclusion that although those scientific experiments in textbook were developed through lots of considerations of expert, to consider the aspect of consumer, it needs to reach the educational agreement about simulation experiment so that It can lead to successful experiment and high quality education.

• Ocean and Polar Research
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• 제30권3호
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• pp.261-275
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• 2008

The profile of a fixed site at station M ($34.77^{\circ}N,\;129.13^{\circ}E$) in the Korea Strait was studied from March 2006 to February 2007. The aim was to understand the relationship between the annual thermal stratification pattern and seasonal variation in phytoplankton community structure. Physicochemical factors including temperature, salinity and nutrient concentrations, which strongly influence the proliferation and diversity of phytoplankton, were measured. The study period was divided into three due to the characteristic of thermohaline structures; mixed I (March-May 2006), stratified (June-November 2006) and mixed II(December 2006-Feburuary 2007). Diatoms dominated during the mixed I (89%) and II (48%) periods, while nanoplankton group occupied over 83% of total population during the stratified period. The dominant species during the mixed I and II was Chaetoceros socialis (47% and 29%, respectively), while during the stratified period Gyrodinium sp.(4%) was the most dominant. Averaged total chl a concentrations during the mixed I and II periods were 0.61 mg $m^{-3}$ and 0.72 mg $m^{-3}$, respectively, which were at least two-fold higher than that during the stratified period (0.30 mg $m^{-3}$). The vertical mixing and convection process of the water column induced nutrient supply from the bottom layer to the euphotic zone. It also led to the dominance of diatoms during the mixed periods, whereas small phytoplankton prevailed over large phytoplankton as stratification blocked the upward movement of nutrients to subsurface during the stratified period. During the mixed I and II periods, microplanktonic chl a dominated concentrations (50% and 48%, respectively), while picoplanktonic chl a occupied over 37% of total chl a during the stratified period.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.241-248
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• 2004

In general, the salient features if the floating breakwater have excellent regulation of sea-water keeping the marine a1ways clean, up and dorm free movement with the incoming and outgoing tides, capable of being installed without considering the geological condition of sea-bed at any water depth, This study discusses the three dimensional wave transformation of the floating breakwater moored by catenary. Numerical method is based at the Green function method and eigenfunction expansion method. The validity of the present is confirmed by comparing it with the result of Ijima et a1.(1975) fer tensile maxed floating breakwater. According to the numerical results, drift and width of the floating breakwater affect at the wave transformation greatly, and incident wave of long period is well transmitted to the rear of the floating breakwater.

• 수산해양기술연구
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• 제52권1호
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• pp.17-23
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• 2016

This study investigates the development of an automatic lightening buoy that can indicate an aquaculture cage at night or in rough weather. The energy for the light is generated by the linear motion of a magnet along with a coil inside the buoy as the waves cause the buoy to oscillate up and down. The principle of the magnet motion is different between the magnet and body of the buoy because the movement of the latter is dependent on the surface wave, while the former is affected by the damper. To obtain a quantitative performance of the buoy, the voltage as well as up and down motion produced by several waves were measured in the wave tank. A shorter wave period, i.e., faster motion, of the magnet produced a brighter light. It is expected that this study can aid in deciding the optimum design of a buoy capable of producing a bright light at any aquaculture site affected by sea or fresh water waves.

• Fisheries and Aquatic Sciences
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• 제26권11호
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• pp.669-677
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• 2023

The spotted seal (Phoca largha) in the Yellow Sea has declined due to poaching and habitat destruction. To aid conservation efforts, Argos satellite tracking were used to monitor the movements of a free ranging spotted seal around Baengnyeongdo Island. The satellite-transmitting tag successfully attached to the seal provided 1,556 location data collected during 107 days. The seal mostly moved between two haul-out sites, Yeonbong Rock and Mulbeom Rock. From October 6th to December 12th, the seal stayed within a 7 km radius of Yeonbong Rock. However, as the signal was lost, it was not possible to identify when the seal started to migrate from Baengnyeongdo Island to winter breeding area. This study provide understanding into the habitat preferences and movement patterns of spotted seals around Baengnyeongdo Island, contributing to the conservation and management of this species. Further research with more individuals and different age groups is essential to understand their habitat preference and develop effective conservation measures for the spotted seal population in the Yellow Sea.

• 한국환경과학회지
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• 제3권2호
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• pp.111-128
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• 1994

서귀포와 부산사이를 취항하고 있는 “카페리 제 주1호”에 수온계를 설치하여 1990년 10월 부터 10 개월간 제주해협과 대한해협을 횡단하는 해역에서 표면수온의 관측을 실시하였다. 그 결과 거문도 부근의 해역에서 뚜렷한 수온전선이 형성되고 있 으나, 그 위치는 약간의 변동성을 냐타내고 있었 다. 전선이 북으로 이동할 때는 비교적 느리고 뚜 렷하나 남으로 이동할 때는 전선구조가 분명하지 않았다. 수온전선에는 수십일 주기를 가진 단주기 변동이 관측된다. 이 변동은 동계 강한 북서계절 풍의 영향과 열이동의 효과로 인한 것으로 사료된 다 표변수온의 수평구배가 3월부터 10월에 걸쳐 매우 약하고, 그 이외의 시기에는 확실하다. 이러 한 결과는 제주해협과 대한해협을 횡단하는 표면 수온의 연속적 인 관측이 한국남안수의 소장과 대 마난류수의 출현 동을 모니터하는데 매우 유효함 을 나타내고 있다. 제주해협과 대한해협에서의 해양관측을 통하여 추자도 부근 해역에서 형성되는 연안전선의 구조 를 파악하였다. 이 전선은 연중 형성되고 있으나, 계절과 연에 따라 그 위치 및 분포형상이 매우 다 르다 이같은 연안전선이 대한해협에서는 매우 약 하게 형성되고 있었다.

• 해양환경안전학회지
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• 제2권1호
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• pp.57-65
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• 1996

The latest date, No. 1 YouII was grounded and sunk into the sea at MAMHYUNGJEDO ( South brother Island) in Sep. 21. 1995, and M.V. Sea Prince of V.L.C.C also made a big oil poullution accident owing to Typhoon "Paei" at front sea of Yeu Choun on Jul. 25. 1995. The large or small scall scale of oil poullution accident frequently was occurred about 300-350 cases per ine(1) year. The countries advanced in marine relations like as, nited Kingdom and Japan, have perfect system The country of expert education, training and oil recovery equipments in oil poullution accidents. The large quantity oil skimming ship's basic condition need general skimming ship which was high speed and large quantity skimming ability , and hve to store the recovered oil into tanks This oil skimming shop are composit the skimmer whuch move up and down according to the wace movements, storage tank which storage the recovered oil in after side, transfer pump which transformed from flooding tank to separating tank and separating tank which separated the oil mixtures, Also there are cylindrical floated which keep the auto positing, gate which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. Also there are cylindrical floated which keep the auto positing, gate which protect and guide the recovering oil from sea and balance weight for skimmer balance. The important arrangement is twin arm which moved by two hinge and move te skimming unit by wave movement. In gate of inside, made long wear in the gate bellow position, there are also connected the flexible hose for oil mixtures drop. The separating tank composited with multi-divided bulkhead for ffective oil and sea water separating by settling and flotation principle. As use the above natural princile and equipment, we can remove the large quantity oil by developed oil skimming ship.ming ship.

• 수산해양기술연구
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• 제55권1호
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• pp.29-38
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• 2019

In order to investigate the behavioral characteristics of Pacific cod (Gadus macrocephalus) released at the entrance of Jinhae Bay, Korea, the direction and range of movement, swimming speed of the fish were measured with an acoustic telemetry techniques in winter, 2015. Three wild Pacific codes WC1 to WC3 (total length 66.0, 75.0, 76.0 cm; body weight 2.84, 2.79, 3.47 kg, respectively) were tagged with the acoustic transmitter. WC1 tagged with an acoustic transmitter internally by surgical method, WC2 and WC3, externally with the acoustic data logger and a micro data logger for recording audible sound waves including timer release unit. The movement routes of the tagged fish were measured more than five hours using VR100 receiver and a directional hydrophone. The directionality of the fish movement was tested by Rayleigh's z-Test, the statistical analysis, and a statistical program SPSS. Three tagged fishes were individually released on the sea surface around the entrance to the Jinhae Bay on 10 to 24 January 2015. WC1 moved about 13.32 km with average swimming speed of 0.63 m/s for six hours. The average swimming depth and water depth of the seabed on the route of WC1 were 7.2 and 32.9 m, respectively. The movement range of WC2 and WC3 were 7.95 and 11.06 km, approximately, with average swimming speed of 0.44 and 0.58 m/s for 5.1 and 5.3 hours, respectively. The average swimming depth of WC2 and WC3 were 18.7 and 5.0 m, and the water depth on the route, 34.4 and 29.8 m, respectively. Three fishes WC1 to WC3 were shown significant directionality in the movement (p < 0.05). Movement mean angles of WC1 to WC3 were 77.7, 76.3 and $88.1^{\circ}$, respectively. There was no significant correlation between the movement direction of fish (WC1 and WC2) and the tidal currents during the experimental period (p >= 0.05). Consequently, three tagged fishes were commonly moved toward outside of the entrance and headed for eastward of the Korean Peninsula, approximately, after release. It may estimate positively that the tidal current speed may affect to the swimming speed of the Pacific cod during the spring tide than the neap tide.