• 한국전자통신학회논문지
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• 제10권2호
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• pp.311-318
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• 2015

우리나라 연안에서 매년 발생하는 적조는 환경적, 경제적인 피해의 발생으로 국가적인 문제로 대두되고 있다. 본 연구에서는 10년간의 해양 기상자료를 수집하여 적조발생에 우호적인 조건을 분석하고 각 해양 기상 요소를 이용하여 2012년부터 2014년까지의 해양 기상상황에 적용하여 적조발생예측을 시도하였다. 그 결과 2012년과 2013년은 실제 적조발생 6~11일 전에 적조의 발생가능경보를 할 수 있었다. 그러나 2014년은 평년에 비해 많은 강수(장마), 낮은 일조시수, 저수온 해역 발생 등의 이유로 적조예측의 정확도가 떨어지는 결과를 얻었다. 따라서 적조발생에 일조량이 미치는 영향을 더욱 고려할 필요가 있으며 추가적인 기상 및 해양요소들의 복합적인 분석이 더욱 필요할 것으로 사료된다.

• 대한원격탐사학회지
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• 제24권4호
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• pp.325-331
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• 2008

본 연구는 MODIS에서 제공하는 클로로필 정보를 기반으로 하여 2단계 필터링을 통해 우리나라 동해, 남해 연안에 대규모로 발생했던 Cochlodinium polykrikoides 적조를 탐지하는 알고리즘을 제시한다. 일반적으로 적조 탐지 연구들은 클로로필과 적조 발생의 상관성을 이용하여 클로로필의 농도가 높은 해역을 적조 발생 해역으로 탐지한다. 하지만 이 방법의 문제점은 적조가 발생하지 않은 해역을 적조 발생 해역으로 탐지함으로써 포함오차(Commission error)를 발생시킨다는 것이다. 따라서 본 연구에서는 이러한 문제점을 극복하기 위해 MODIS에서 제공하는 클로로필 정보를 바탕으로 적조 발생 해역을 추출하고, 2단계 필터 링 과정을 적용함으로써 진해, 여수, 남해도 부근 해역에서 발생한 포함오차를 제거하였으며, 그 결과를 국립수산과학원의 적조속보자료와 함께 시각적 정량적으로 평가하여 본 연구에서 제안한 알고리즘의 효용성을 검증하였다.

• 한국물환경학회지
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• 제27권4호
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• pp.542-550
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• 2011

Changes of suspended sediment concentration in the Seomjin river estuary located in south sea of the Korea peninsula were investigated during the spring tide in autumn (i.e. 25 hours in October) 2000 and winter (i.e. 25 hours in February) 2001. The changes of temperature and salinity during the spring tide in October 2000 showed larger variations than the those in February 2001. During the spring tide in October 2000, currents at bottom layer were observed to be stronger than during the spring tide in February 2001, showing that both of the two periods had ebb currents-predominant tide asymmetries. The suspended sediment concentrations in October 2000 were larger than the those in February 2001. At the time of the maximum of tide currents or after about one hour of the maximum during the autumn months, the suspended sediment turbidity was observed to be maximum. Another observation station at Hadong upstream from the Seomjin river estuary showed about one hour delay in tide phase, Thereby, the suspended sediment concentration showed high turbidity after two hours at bottom and three hours at surface layer, in particular, in October 2000. This results can be explained by the facts that river discharge increased significantly after the summer rainy season, causing also increase of erosion processes by strong current velocity at bottom layer.

• 한국전자통신학회논문지
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• 제3권2호
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• pp.101-105
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• 2008

인터넷 웹상으로 제공되는 조석정보 서비스는 여럿 있지만 인터넷이 안 되는 무선통신 환경에서 제공되는 조석정보 서비스는 없다. 따라서 본 논문에서는 사용자가 휴대폰과 같은 개인 휴대용 단말기를 통해 간단한 조작을 거쳐 손쉽게 조석정보 서비스를 제공 받도록 모바일 조석정보 서비스를 설계하여 구현 하였다. 이는 XHTML, CSS 등을 이용하여 플랫폼 독립성 특징인 웹 표준을 준수하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1048-1049
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• 2015

The sihwa tidal power plant is the first tidal power plant in korea and the biggest of the world. The tidal power turbine is operated by tidal energy. The tidal energy is generated by the relative motion of the earth and celestial masses specially the sun and the moon, which interact via gravitational forces. The tidal power is estimated by the predicted the tidal amplitude and phase. This paper gives a process of estimate of tidal power using Matlab T-tide based on tide prediction. The proposed method is tested using actual recorded data comparing to predicted date.

• 한국환경과학회지
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• 제6권3호
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• pp.231-238
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• 1997

The community of phyloplankton and water quality were Investigated 5 times from October, 1994 to October, 1995 In the east area of Chinhae Bay. Seasonal changes of enoronmental parameters were shown general pattern and related to the red tide mechanism of phytoplankton community. Seasonal variations of dissolved oxygen concentrations were affected by the photosynthetic activity of phytoplankton community and the Increase of COD at the bottom water was occurred after the red tide. The standing stocks of phytoplankton In this study area ranged 202 - 1616 Cells . ml-1 and the bloom(red tide) was formed from April to July. The diatom species, Skeletonema costahm was a dominant species all the year round and the dinoflagellate species, Alexandrium tmuense and prorocentrum triestinum were red tide species Increased standing stocks in phytoplankton bloom.

• 한국해양공학회지
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• 제33권6호
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• pp.573-580
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• 2019

A submerged breakwater is a coastal structure built under water with excellent landscape. The depth of the crest of the breakwater should be maintained at more than a certain level in order for the submerged breakwater to control waves properly. This means that the effect of blocking waves deceases sharply at high tide in coastal areas with large tidal differences. In this study, we proposed a Tide-Adapting Submerged Breakwater (TA-SB) to overcome this problem, and then we conducted hydraulic model experiments to evaluate the performance of the TA-SB for controlling waves. The experimental results showed that the tapered wings attached to the crest of the TA-SB helped induce forced breaking waves. In particular, they were very effective in blocking waves and attenuating wave energy at high tide. In addition, the wave control performance of the proposed TA-SB was far superior to the Tide-Adapting Low-Crested Structure (TA-LCS) of the previous study.

• 한국농공학회논문집
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• 제55권2호
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• pp.1-8
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• 2013

This study was performed for the purpose of analyzing the effect of tide on the stress-strain behavior in the boundary surface of sea dike embankment. Tide is a dynamic condition, but there are not suitable numerical models to solve the dynamic embankment condition caused by tide. So the analysis was simplified to quasi dynamic as follow. First, seepage by tide was analyzed according to elapsed time, and the results of the analysis at every hour during one periodic cycle time of 12 hours were applied to the pore water pressure conditions of stress-strain analysis with hyperbolic model by Duncan and Chang. The place at which maximum shear strain took place in the analysis result moved up and down repeatedly along the boundary of the dredged sand fill section and the crashed stone filter section. The value of maximum shear strain was large at high water level of tide. This result means that contraction and relaxation occur in turn repeatedly at every specific position along the boundary, and the repeated action compact loose position with sand moved down from the upper position by gravity. The experiment with the small sea dike model showed the result consistent with the numerical analysis. The surface of sea side on the dike collapsed at high water level after a couple of repetition of the rising and falling of water.

• 한국수산과학회지
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• 제25권5호
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• pp.359-370
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• 1992

To investigate the flow pattern and mixing process in Suyoung Bay, field observations and data analyses of tidal current, salinity and suspended sediment (SS) were carried out. Ebb flow is stronger than flood flow, and duration of ebb tide is longer than that of flood tide. Semi-diurnal component of tidal current is predominant, and current rotating clockwise occurs in the central part of the bay. The direction of the residual currents in the central part of the bay and offshore is almost N to WNW, and the speed is 4-14cm/s. Eulerian diffusion coefficients estimated from the current data have the range of $6.2\times10^4-4.2\times10^6\;cm^2/s,$ Salinity structure in Suyoung River estuary during flood tide is of partially mixed type, but is of stratified type during ebb tide. Salinity fluctuation is large at the surface, and the fluctuation decreases with depth. SS concentration in Suyoung River estuary has a higher value during ebb tide than that during flood tide. Salinity and 55 concentrations in the estuary appeared to be very sensitive to the change of river flow.

• 지구물리와물리탐사
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• 제14권2호
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• pp.133-139
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• 2011

지구조석을 계산하는데 있어 가장 주요한 항은 달이나 태양에 의한 구면조화차수가 2인 항으로서 지구조석의 약 98%를 이루며, 나머지는 3차 이상의 고차 항들이다. 그런데 차수 3항과 그 이상의 고차수의 항들의 값들은 차수 2항과는 다른 상수가 각각 곱하여져서 계산되어야 한다. 본 연구에서는 조석에 의한 중력변화, 변위 및 수직선의 변화에 대한 바른 계산을 검토하였으며, 필요한 관련상수들을 다시 구하였다. 동일차수내의 다른 계수의 조화함수적 조석주기의존성을 토의하였다. 한편, 지구조석을 계산하는데 관련된 중요한 개념들을 요약 소개하였다.