• 한국해양생명과학회지
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• 제5권2호
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• pp.58-63
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• 2020

척삭동물문에 속하는 붉은멍게(Halocynthia aurantium)는 우렁쉥이와 같이 유용한 양식 품종으로 사료되지만, 발생과 생태 등 생물학적 특성에 대해 잘 알려지지 않았다. 본 연구에서는 붉은멍게 양식을 위한 기초자료를 얻기 위해 강원도 동해 연안에 서식하는 붉은멍게의 배발생을 조사하여 근연종인 우렁쉥이와 비교하였다. 그 결과, 붉은멍게의 수정부터 난할기, 낭배기, 신경배기의 배아 및 올챙이형 유생의 발달 단계 및 형태가 우렁쉥이와 매우 유사하였다. 붉은멍게의 수정란은 수온 11℃에서 부화까지 약 42.1시간이 소요되어 우렁쉥이의 40.9시간과 거의 유사하였다. 부화 후 어린개체로 변태하는 데 소요되는 시간도 두 종 사이에서 매우 유사하였다. 수온 11℃에서 부화한 두 종의 유생은 모두 약 23일이 경과해서 입수공과 출수공이 명확하게 구분되는 어린개체로 발생하였다. 수온 변화에 따른 발생 속도는 저온에서 느렸고 고온에서 빠른 결과를 나타냈다. 붉은멍게의 경우는 9℃에서 부화까지 평균 62.3시간, 11℃에서 42.1시간, 13℃에서 36.3시간이 소요되었다. 우렁쉥이의 경우는 평균 60.4시간, 40.9시간, 35.2시간이 소요되었다. 붉은멍게 배아의 대부분은 수온 15℃ 이상에서 정상적으로 발생이 이루어지지 않아 종묘생산 과정에 주의가 필요한 것으로 사료된다.

• 대한원격탐사학회지
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• 제39권6_2호
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• pp.1605-1613
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• 2023

해양 내의 다양한 물리적 변화는 수온과 염분의 지속적인 변동에 의해 결정된다. 수온과 더불어 넓은 영역의 염분 변화를 파악하기 위해서는 인공위성 자료에 의존할 수밖에 없다. 그럼에도 불구하고 염분을 관측하는 위성인 Soil Moisture Active Passive (SMAP)는 낮은 시·공간 해상도로 인해 연안 근처에서 빠르게 변화하는 해양환경을 관측하기에는 어렵다는 한계가 존재한다. 이러한 한계를 극복하기 위해 본 연구에서는 천리안 해양 관측 위성의 정지궤도 해색 센서인 Geostationary Ocean Color Imager-II (GOCI-II) 원격반사도 자료를 입력자료로 하여 고해상도 표층 염분을 산출하는 Multi-layer Perceptron Neural Network (MPNN) 기반의 알고리즘을 개발하였다. SMAP과 비교한 결과 coefficient of determination (R²)는 0.94, root mean square error (RMSE)는 0.58 psu 그리고 relative root mean square error (RRMSE)는 1.87%였으며, 공간적인 분포 또한 매우 유사한 결과를 나타냈다. R²의 공간 분포는 0.8 이상을 보여주었으며 RMSE는 전반적으로 1 psu 이하의 낮은 값을 보여주었다. 이어도 과학기지에서의 실측 염분값과도 비교하였지만 상대적으로 조금 낮은 결과를 보여주었다. 이에 대한 원인을 분석하였으며, 산출된 GOCI-II 기반 고해상도 염분 자료를 활용하여 2022년 11호 태풍 힌남노에 의한 하루 동안의 동중국해 표층 염분 변화를 표준편차로 계산하였다. 그 결과 SMAP에서 관측할 수 없는 시공간의 염분 변화를 고해상도의 GOCI-II 기반 염분 산출물을 통해 확인할 수 있었다. 따라서 본 연구를 통해 시간 단위로 변화하는 해양환경 모니터링에 큰 기여를 할 것으로 기대된다.

• 수산해양기술연구
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• 제47권4호
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• pp.327-337
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• 2011

This study was conducted to develop energy-efficient LED lamps with an excellent fishing performance for an anchovy scoop net by comparing the functions of 6 different lamps- incandescent, blue LED, green LED, white LED, yellow LED and red LED lamp. We used incandescent and red LED lamps only for the initial test and then excluded because those showed the lowest herding capacity. According to the result, yellow LED showed lower herding capacity in comparison with the blue, green and white one. Although the herding performance of the blue, green and white LED was similar in almost tests, herding speed to the each light was different. The anchovies were gathered into the blue LED as the speed of 39.88cm/s that was the fastest. Green LED was the second as the speed of 33.28cm/s. White LED was the slowest as the speed of 26.73cm/s. We will have field tests because we found the result that yellow LED's herding performance was better than green LED's for 5 seconds comparing after starting in some tests.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.88-95
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• 2012

In this study, in order to utilize the seawater as a heat source at Gangneung city near the East Sea in Korea, an annual heating performance of a screw heat pump was simulated. For a simulation, the maximum heating capacity of heat pump was assumed at 3.5 MW. An ambient temperature at Gangneung city was calculated from the TMY2 weather data, while the seawater temperature was calculated from the regression equation based on the measurement by the National Fisheries Research and Development Institute of Korea. The heating load was assumed linearly dependent on the ambient temperature, while the maximum heating load was assumed to appear when the ambient temperature is below $-2.4^{\circ}C$, which is the temperature of TAC 2.5% for heating at Gangneung city. A heat pump performance at full-load was calculated from the regression equation, which involves refrigerant's evaporating and condensing temperatures, based on a commercial screw compressor performance map. A heating supply temperature which determines refrigerant's condensing temperature was assumed linearly dependent on the heating load. A performance degradation due to the part-load operation of heat pump was also considered. Simulation results show that an annual heating coefficient of performance ($COP_H$) of a seawater-source screw heat pump is approximately 2.8 and that it is necessary to improve part-load performance to increase an annual performance of the heat pump.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2003년도 춘계공동학술대회논문집
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• pp.165-170
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• 2003

파랑에너지를 차단하고 항내 정온을 확보하기 위해 설치된 외곽시설인 방파제는 불투과성이기 때문에 항만을 폐쇄성으로 만들 수 있으며, 외간의 해수교환은 급격히 감소될 수 있다. 항만개발의 최근 추세는 항내의 수질 보호와 친수성이 강조되어, 기존의 불투과성 방파제의 일부에 투과성으로 설계한 제체투과성 해수교환방파제를 설치하여 외해의 에너지가 항내로 전달되어 항내 오염물질의 희석률 증대와 함께 외해로 배출되도록 하고 있다. 오염이 심화된 항만에서 항내 수질을 개선하기 위한 방안은 육상오염원을 제거하는 것이 최선이나, 폐쇄성이 큰 항만의 경우, 외해와의 해수순환을 강화시켜야만 한다. 즉, 기존의 항만에서의 항내 수질개선을 위해서 외곽시설의 일부에 해수소통구를 두는 방법이 가장 최선이라 할 수 있다. 본 연구에서는 항내 오염이 심각한 항만을 대상으로 하여, 해수소통구를 통한 해수순환 양상을 검토하고 수반되는 해수교환을 검토하고자 한다. 이를 위해 해수유동 및 오염확산 수치모델을 구축하고 대안에 따른 항내의 해수순환 및 해수교환을 평가하였다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제10권S_2호
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• pp.55-63
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• 2001

This work employs two models to quantify the size-segregated dry deposition fluxes of particle-bound N $O_3$$^{[-10]}$ , N $H_4$$^{+}$, and S $O_4$$^{2-}$ along the coastal area of Jeju Island based on the chemical composition data of aerosol collected during the springtime of 1995. The two approaches produced fairly comparable results, despite the feature differences between the two models. The modelling results obtained indicated that the mean dry deposition velocity was around 0.4 cm $s^{-1}$ for N $O_3$$^{[-10]}$ , 0.2 cm $s^{-1}$ for N $H_4$$^{+}$, and 0.3 cm $s^{-1}$ for S $O_4$$^{2-}$, and the dry deposition flux varied between 371~1368 $\mu\textrm{g}$ $m^{-2}$ da $y^{-1}$ for nitrate, 28~625 $\mu\textrm{g}$ $m^{-2}$ da $y^{-1}$ for ammonium, and 957~6088 $\mu\textrm{g}$ $m^{-2}$ da $y^{-1}$ for sulfate. Although difficulties in collecting giant and/or fine particles limited the understanding of the mass size distribution of particles and thus the ability to refine estimates of the dry deposition flux for the particulate matter, both models were still able to offer sufficient realism to explain the features of the available data collected from the coastal area of Jeju Island.and.

• 수산해양기술연구
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• 제21권2호
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• pp.123-130
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• 1985

Loran-C 위치의 정도를 높이기 위하여 제주지역을 대상으로 북동태평양 Chain (GRI 5970)에 대한 시간차를 관측하여 그 전파경로와 측지계 및 전파속도에 따른 시간차오차 등을 분석 검토한 결과는 다음과 같다. 1. Loran-C 전파는 M-X 조국, M-Y조국 모두 주국, X, Y 종국과 관측점 사이에 높이 500m 이상 되는 한라산을 통과하여 전파될 때 시간차 오차가 커짐을 알 수 있었다. 2. 측지계 및 전파속도의 보정에 따른 시간차오차는 M-X 조국에서는 측지계변환과 속도보정을 행할수록 적어지고, M-Y조국에서는 M-X조국과는 달리 해상 및 육상의 전파경로에 따라 시간차오차가 불규칙적으로 변함을 알 수 있었다. 3. 보정요소별 측위의 정도는 측지계를 변화하고 속도보정을 행한 것이 가장 높고, WGS-72 측지계를 변환시키지 않은 것이 가장 낮았다. 4. 측정위치의 정도를 향상시키기 위해서는 굴절율에 의한 속도보정과 측지계변환 및 육상전파속도보정을 행하여야 함을 알 수 있었다.

• 수산해양기술연구
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• 제49권2호
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• pp.116-125
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• 2013

Jigging and angling fishery is prevalent in the East Sea of Korea and this fishery needs many lamps to attract the fish. And the fishing boat uses 24~47 ballasts by the vessel's tonnage to turn on the fishing lamp. A 3.5kW magnetic-type ballast being currently used at many fishing boats can drive two 1.5kW metal-halide lamps. Meanwhile, this ballast has large weight (25kg) and volume. Therefore it is one of reason for the over-consumption of energy and the fire, resulted from overheat and electrical short, occurs occasionally because the ballast is installed at narrow and hot engine room. In addition, most of magnetic ballast has several problems such as periodic condenser replacement, low energy efficiency and making lamp short life, etc. So it is necessary to improve or develop newly the electronic ballast, which has to be smaller, lighter and more efficient. An electronic ballast was designed for the fishing boat by considering duration and electromagnetic interference in the study. Its weight and volume are respectably 40% and 66% compared to current ballast on the basis of PCB. The metal-halide lamp's spectrum of the designed ballast was nearly same to that of the current ballast in the test of lighting. In particular, the light stability was improved and there isn't any radio interference. As mentioned above, it is expected that the developed electronic ballast can replace current magnetic ballast because of many advantages related to energy-saving.

• 수산해양기술연구
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• 제57권2호
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• pp.173-184
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• 2021

In this study, internationally widely utilized bioeconomic models were used to make a comparison and analyze the effectiveness of red snow crab fisheries management measures. As a specific effect analysis, biological and economic effects of both total allowable catch (TAC) and effort reduction management measures were analyzed simultaneously. Model results showed that the red snow crab biomass would be decreased from 106,000 tons to 73,076 tons after ten years when the TAC is set to and maintained at the current level of 26,000 tons. The amount of biomass would be increased to 125,316 tons when the level of TAC is set to 22,000 tons. In cases of reduced fishing efforts, a 30% decrease from the current level would result in greater biomass and NPV would be also estimated at the highest level. In addition, a sensitivity analysis by market price was conducted to analyze the minimum TAC level of the red snow crab offshore pot fishery. Results showed that the minimum TAC level would be 8,210 tons when the market price increased by 30% and it would be also 15,247 tons when the market price decreased by 30%. Furthermore, results of the sensitivity analysis by fishing cost showed that the minimum TAC level was analyzed to be 13,857 tons when the fishing cost increased by 30% from the current level.

• 수산해양기술연구
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• 제47권4호
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• pp.411-418
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• 2011

As a fish way is a structure for fish migrating well toward upper stream due to breaking river flow by a dam or dammed pool, the specific fish's swimming ability is one of the main factors in making a plan and managing it. In addition, it also needs to understand the current field in fish road to evaluate its performance. This study is aimed to analyze the swimming patterns with current velocity changes using a Particle Imaging Velocimetry (PIV) in order to understand the swimming ability of silver fish (Plecoglossus altivelis) that is one of the fishes migrating through the fish way of Nakdong River, and to analyze the 2 dimensional current field near to silver fish at swimming momentum. The results showed that average values of tail beat frequencies for continuous swimming with current velocity were 2.8 Hz at 0.3 m/s, 3.2 Hz at 0.4 m/s, 3.8 Hz at 0.5 m/s, respectively. The wake would be produced by direction turning of fish's tail fin and its magnitude would be verified by the difference of pressure. The pressure turbulent flow produced by its tail beat would be made in both sides, and then, the magnitude of wake should be the source of moving direction. The swimming momentum will help to support the primary factor in making a suitable design for specific fish species migrating toward the district river.