• 제목/요약/키워드: Tidal

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마산변의 해수교환율 (Tidal Exchange Ratio in Masan Bay)

  • 김종화;장선덕;김해용
    • 수산해양기술연구
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    • 제22권3호
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    • pp.29-35
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    • 1986
  • The characteristics of tidal exchange in Masan Bay were studied on the basis of salinity observations and current measurements in the summer of 1985. The exchange ratio of the sea water was calculated using three different formulas. The tidal exchange rate was estimated to be smaller than that of another bays in the southern coast of Korea. The tidal exchange ratios in Masan Bay at spring tide were deduced to be 2.4-11.7%. While those at neap tide were 2.0-9.1%. Though tidal range of neap tide is smaller than that of spring tide. the tidal exchange ratio in the bay can be increased in case of highly stratified vertical structure.

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A Numerical Experiment On Tidal Currents In Asan Bay

  • Ahn, Hui Soo;Lee, Suk Woo
    • 한국해양학회지
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    • 제11권1호
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    • pp.18-24
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    • 1976
  • The distribution of tidal currents in Asan Bay was simulated by a numerical experiment. A homogeneous and single layer model with bottom stress taken into account was used. Although the effective configuration of the bay differs significantly between the high tide and the low tkde, its form is assumed to be fixed as a first approximation. The advective term is particularly large because the tidal range of 810cm is large compared to the depth and the changes of velocities occur abruptly. The results of calculations agree fairly well with the observations. For example, the tidal range at Manhoriis amplified 15cm higher and the phase lag is five minutes later than at the mouth of the bay. It also can generally be said that, with the semidiurnal tide at the mouth of the bay, the tidal range is increased toward the inner corner and that tidal currents are found to be large at the deeper part of the bay.

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Topography in intertidal zone by satellite images

  • Kang, Yong-Q.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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    • pp.664-669
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    • 2002
  • Intertidal zone (tidal flat) is a place which is sometimes dry and sometimes wet depending on the tidal rhythm. Direct measurement of topography in the intertidal zone is very difficult to be achieved. The interface between wet and dry parts in the tidal flat, which can be identified from near infrared band of satellite image, is a 'depth contour' which corresponds to the sea level at the time of satellite pass. Aquisition of topography data in tidal flat is possible by combining various techniques such as (1) identification of the interface between wet and dry parts, (2) GCP correction of satellite image, and (3) realtime prediction of sea level elevation at the time of satellite pass. The algorithm was successfully applied in obtaining topography (bathymetry) data in the intertidal zone of Asan Bay in the west coast of Korea from 26 satellite images. The method is expected to be very efficient in making bathymetry data base in the western and southern parts of Korea where tidal flats are well developed in wide regions.

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대.소조기변동에 따른 득량만내의 부유퇴적물의 변동 및 분포특성 (The Variations of SMC During Tidal Cycle in Deukryang Bay, Korea)

  • 이병걸;공영세;조규대
    • 한국환경과학회지
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    • 제5권4호
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    • pp.473-479
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    • 1996
  • The temnoral variations of the suspended material concentration (SMC) during spring-neap tidal cycle was investigated at more than 30 stations in Deukryang Bay, Korea, in 1 and 23 July, 1992. The averaged total SMC in spring tide was two times more than those in neap tide. It can be explained that the strong tidal current in spring tide disturbed bottom waters and induced higher SMC in the bay. The areal distributions of SMC for the surface and the bottom layers in the bay shows much different patterns during spring and neap tidal cycle. We concluded that the vertical stratification intensity of water mass is important factor of the horizonatal distribution of SMC in the bay.

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수평축 조류발전 후류 특성 및 발전 효율 분석 (The Wake Characteristics of Tidal Current Power Turbine)

  • 조철희;이강희;이준호
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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    • pp.163.2-163.2
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    • 2011
  • Due to global warming, the need to secure an alternative resource has become more important nationally. Due to the high tidal range of up to 9.7m on the west coast of Korea, numerous tidal current projects are being planned and constructed. To extract a significant quantity of power, a tidal current farm with a multi-arrangement is necessary in the ocean. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system, and its performance is determined by various design variables. The power generation is strongly dependent on the size of the rotor and the incoming flow velocity. However, the interactions between devices also contribute significantly to the total power capacity. Therefore, rotor performance considering the interaction problems needs to be investigated for generating maximum power in a specific field. This paper documents the characteristics of wake induced by horizontal axis tidal current power turbine.

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東支那海의 觀測潮流 및 計算潮流 (Observed and Computed Tidal Currents in the East China Sea)

  • 최병호
    • 한국해양학회지
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    • 제20권1호
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    • pp.56-73
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    • 1985
  • 黃海 및 東支那海의 三次元 水動力學的 數値모델이 기보고된 主太陰半日週潮 (M2)의 潮流分布(崔, 1984)에 附加하여 S$_{2}$, $K_{1}$, 및 $O_{1}$ 分潮의 水深에 따른 潮流分布를 算定하는데 利用되었다. 모델 結果는 近年의 美.中共 共同 海洋觀測 프로그램의 潮流觀測値( Larsem과 Cannon, 1983)와 比較檢討되었으며 또 한 S$_{2}$, $K_{1}$$O_{1}$ 分潮의 表層, 中間水深, 海底에서의 潮流 調和 常數 分布圖 및 潮流 圓圖로서 提示되었다.

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국내외 해양 조류발전 기술 (Recent Ocean Tidal Stream Power Generation Technology)

  • 조철희;박관규
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 추계학술대회
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    • pp.134-137
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    • 2006
  • Tidal power can use conventional technology to extract energy from the tides. It is usually best deployed in areas where there i s a high tical range which includes Western and Southern coastal areas in Korea. However, to extract tical energy, a barrage across an estuary or a bay is to be constructed that is now very hard due to severe environmental impact on local estuary. The recent technology of application of tidal stream provides a new window to extract power minimizing the adverse environmental impact Tidal stream technology which directly exploits these currents is relatively new but is presently generating considerable interest Turbine rotors can be used to extract energy from the flows. Prototype devices currently on test in the UK include the 300kW SeaFlow turbine. In this paper, the recent technology and research on ocean tical stream power are addressed

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하천 감조부에 있어서 질소의 장기변동에 관한 연구 (Study on the Long-term Change of nitrogen in the Tidal Area of River)

  • 김원규;강주복
    • 물과 미래
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    • 제25권2호
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    • pp.67-78
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    • 1992
  • Several field surveys were conducted to investigate changes of water quality with time in a tidal river. Results indicated that nitrification process were dependent on the change of salinity and suspended solids concenttration. Therefore laboratory batch experiments were conducted, using suspended solids and sediment taken from a tidal river, to study the effect of salinity on nitrification and to estimate kinetic parameters of it in the tidal river. suspended solids and sediment were sampled at a point in the middle stream. Sediments were collect from the aerobic layer of mud. The change of nitrogen concentration with time was clearly explained with Monod groth model and kinetic parameters were obtained by curve fitting method. Changes in NH4-N, NO2-N, and NO3-N concentrations in the river ROKKAU with time were simulated well using Lagrangian reference frame and parameter values obtained in the laboratory tests. T도 mechanism of nitrification by suspended solids and sediment in a tidal river is shown to depend on tidal effects.

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Depth contours appeared on SAR images by interactions between tidal current and bottom topography

  • Kim, Tae-Rim
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.692-694
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    • 2006
  • X-SAR images taken on the coastal waters of Hwanghe province in Korea during SIR-C/X-SAR campaign in April and October 1994 are analysed. The SAR images show the peculiar signatures like nail marks, curved long string, and vortex streets patterns and they all seem to be produced by strong interactions between the topography in the coastal waters and tidal currents. The nail mark signatures are located at the same position of small scaled sand banks and the curved line patterns are almost identical to the outer boundary of large sand banks. Based on the tidal record, all the three images are taken at the almost same phase of tidal cycles, which are close to the low tide. It seems that bottom shapes are more strongly appeared on the SAR images when the tidal currents are slow. The front between two different current velocities caused by the flows along the steep boundaries of sandbanks is also the main factors imprinting the bottom features to the sea surface SAR images

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A Study on Energy Extraction from Tidal Currents

  • 황안둥;양창조
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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    • pp.79-79
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    • 2011
  • The oceans are an untapped resource, capable of making a major contribution to our future energy needs. In the search for a non polluting renewable energy source, there is a push to find an economical way to harness energy from the ocean. Tidal stream is one of ocean energy form that is being investigated as potential source for power generation. Tidal current turbines are therefore designed as conversion machinery to generate power from tidal currents. A study on energy extraction from tidal currents is presented in this paper.

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