• Title/Summary/Keyword: Sea Field

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Numerical Simulation of Dispersion of a Vast Point Source in Coastal Area using the Local Wind Model (국지풍모델을 이용한 연안지역 거대 점오염원의 이류확산 수치모의)

  • 전병일
    • Journal of Environmental Science International
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    • v.7 no.4
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    • pp.511-522
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    • 1998
  • The two-stage numerical model was used to study the relation between three-dimensional local wind seal area for Korean peninsula. The first stave is three dimensional time-dependent local wind model which elves the wind field and vertical diffusion coefncient. The second stage is advection/duusion model which uses the results of the first stage as input data. First, wand fields on Korean peninsula for none synoptic scale wand showed typical land and sea breeze circulation, and the emitted particles were transported by sea breeze for daytime, emissions return to sea by land breeze for nighttime.

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Survival and growth of the red tide organism Cochlodinium polykrikoides after the addition of yellow loess

  • Lee, Young-Sik;Lim, Wol-Ae;Lee, Sam-Geun
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2008.11a
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    • pp.282-285
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    • 2008
  • At least 15% of the C polykrikoides cells that precipitated to the bottom layer either by the addition of loess or no addition survived for 1 week at all growth phases, rather than disappearing immediately after precipitating. However, no live cells were observed after 20 days, regardless of phase or loess addition. In the exponential phase, the number of C polykrikoides cells increased to >2886 cells/ml after loess was added. However, in the stationary phase, the number of cells did not increase until 18 days. In the exponential phase, those C polykrikoides that survived precipitation caused by scattering loess on cultures did not appear to have the ability to cause red tides again because of the short red tide periods in the field, long lag time after loess addition, and low survival rate after loess addition.

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Numerical Simulation of Advection and Diffusion using the Local Wind Model in Pusan Coastal Area, Korea (부산 연안역에서의 국지풍모델을 이용한 이류확산 수치모의)

  • 김유근;이화운;전병일
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.1
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    • pp.29-41
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    • 1996
  • The two-stage numerical model was used to study the relation between three-dimensional local wind model, advection/diffusion model of random walk method and second moment method on Pusan coastal area. The first stage is three dimensional time-dependent local wind model which gives the wind field and vertical dirrusion coefficient. The second stage is advection/diffusion model which uses the results of the first stage as input data. First, wind fields on Pusan coastal area for none synoptic scale wind showed typical land and sea breeze circulation, and convergence zone occured at 1200LST in northern of domain, in succession, moved northward of domain. Emissions from Sinpyeong industrial district were trasnported toward the inland by sea breeze during daytime, and reached the end part of domain about 1800LST. During nighttime, emissions return to sea by land breeze and vertical diffusion also contributes to upward transport. In order to use this model for forecast of air pollution concentration on the Pusan coastal area, it is necessary that computed value must be compared with measured value and wind fields model must also be dealt in detail.

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Initial Experiment Results in the Development of a L-Band Microwave Radiometer for Remote Sensing of Sea and River Surface Salinity (해수 및 하천수의 염분농도 원격탐사용 L-Band M/W Radiometer의 개발 및 초기 실험결과)

  • Kim, Sang-Bong;Kim, Ji-Hoon;Son, Hong-Min
    • Proceedings of the KSRS Conference
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    • 2007.03a
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    • pp.65-69
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    • 2007
  • A L-Band microwave radiometer for remote sensing of sea and river surface salinity has been developed. The processes of the design and implementation of the microwave radiometer, and the experiment results are presented in this paper. The developed L-Band microwave radiometer was field-tested in Sum-Jin River. The initial results shows that the microwave radiometer measures the sea and river surface salinity with the sensitivity of 1.5psu successfully.

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A Study on the Civil Maritime Guarder to Enhance the Service of Coast Guard (해양경비 서비스 개선을 위한 경비지도사 제도에 관한 연구)

  • Jin, Sung-Yong;Park, Sung-Yong;Ju, Jong-Kwang;Lee, Eun-Bang
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.115-119
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    • 2007
  • The system of civil security service is analyzed and reviewed in order to induce it to maritime security domain. A system of civil maritime guarder who provides security service and cooperates with coast guard at sea is proposed. It is expected not only that some expecters on the field of maritime security service are built up but that the Qualities of security services are improved in considering characteristics of sea control and coast guard.

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The Prediction of Remaining Service Life of Land Concrete Due to Steel Corrosion (철근부식에 의한 육지 콘크리트의 잔존수명 예측)

  • 정우용;윤영수;송하원;변근주
    • Journal of the Korea Concrete Institute
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    • v.12 no.5
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    • pp.69-80
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    • 2000
  • This paper presents the prediction of remaining service life of the concrete due to steel corrosion caused by the following three cases; carbonation, using sea sand and using deicing salts. The assessment of initiation period was generalized considering the existing perdiction models in the literature, corrosion experiment and field assessment. To evaluate the prediction equation of rust growth, the corrosion accelerating experiments was performed. The polarization resistance was measured by potentiostat and the conversion coefficient of polarzation resistance to corrosion rate was determined by the measurement of real mass loss. Chloride content, carbonation, cover depth, relative humidity, water-cement ratio(W/C), and the use of deicing salts were taken into account and the resulting prediction equation of rust growth was proposed on the basis of these properties. The proposed equation is to predict the rust growth during any specified period of time and be effective in particular for predicting service life of concrete in the case of using sea sand.

Recent Developments of Wave Energy Utilization in Denmark

  • Kofoed, J.P.;Frigaard, P.;Kramer, M.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.91-98
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    • 2006
  • This paper aims at giving an overview of the developments researchers at the Department of Civil Engineering, Aalborg University, Denmark (DCE), have been involved in within the field of wave energy utilization in Denmark over the past decade. At first a general introduction is given followed by a more thorough description of three ongoing projects. These are Wave Dragon, Wave Star and Seawave Slot-cone Generator. Common for these projects are that they are being, or will soon be, tested in real sea and have benefited from the Danish Wave Energy Program. The work by the department on these projects involves substantial laboratory testing, numerical simulations and real sea prototype testing.

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A Study of Performance Improvement of a Vaporizer Sea-Water Pump (기화해수펌프 성능 개선에 대한 연구)

  • Kim, Yang-Ik;Chung, Kyung-Nam
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.645-649
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    • 2005
  • In this study, redesign of a vaporizer sea-water pump has been carried out using computational fluid dynamics. The flow field of the specified pump model is simulated and analyzed. In the flow analysis full pump model has been used, and multi-block grids are employed to solve the governing equations. In order to improve pump efficiency, systematic redesign has been performed to remove the flow recirculation near the hub of the diffuser vanes. The modified model shows about 4 % improvement in pump efficiency compared to the given model.

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Hydraulic Characteristics of water affinity sea-wall block (환경친화형 친수호안(親水護岸)블록 수리특성)

  • Han, Jea-Myung;Oh, Young-Min
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.2
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    • pp.179-182
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    • 2007
  • In this study hydraulic model experiment was conducted to identify the performance of newly developed water affinity sea-wall block to keep the coastal line from eroding and supply water affinity space by reflection coefficient and safety. In the result, the block is applicable to the field.

Wave Breaking and Breaking Wave-Induced High Frequency Pressure over Submerged Breakwater (잠제에 의한 쇄파 및 쇄파에 의해 발생하는 고주파수파동압)

  • Koichiro IWATA;Koji KAWASAKI;Hirokazu SUMI
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2002.08a
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    • pp.14-23
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    • 2002
  • Wave breaking and breaking wave-induced hydrodynamics are very important subjects in the field of coastal and ocean hydrodynamics and engineering. In the coastal zone, a submerged breakwater has been increasingly popular, since it is one of nature-matching structures with multi- functions such as (1) wave energy dissipation by wave breaking and friction, (2) oxygen supply to sea by wave breaking and breaking wave, (3) water purification by entrained air bubbles, (4) keeping. good seascape. and (5) good habitat for sea livings. Recently, the breaking wave-induced high frequency pressure over a submerged breakwater is said to have a function of gathering sea livings around the structure, which has encouraged the construction of the submerged breakwater in coastal zone. (omitted)

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