• Title/Summary/Keyword: Coastal ocean

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Review of Internal Waves in Ocean (해양에서의 내부파)

  • Cho, Yong-Sik;Lee, Bong-Hee;Yoon, Tae-Hoon
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 2000.09a
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    • pp.113-119
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    • 2000
  • Internal waves, including all kinds of wave phenomena inside a stratified fluid system, have been a subject of interest for a long time in geophysics, coastal and ocean engineering, applied mathematics and hydrodynamics. The vast oceans on the earth are a complex stratified fluid system widely distributed with pycnoclines, which are horizontally layered regions with a large density variation, commonly located about 50-150 meters below the ocean surface. (omitted)

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Application of time-dependent wave equations to random waves over ripple patch

  • Lee, Chang-Hoon;Suh, Kyung-Doug;Park, Woo-Sun
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1996.10a
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    • pp.109-114
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    • 1996
  • In a linear dispersive system, the combined effect of water wave frnnsformations such as refraction, diffraction, shoaling, and reflection can be predicted by the mild-slope equation which was developed by Berkhoff (1972) using the Galerkin-eigenfunction method. In the derivation of the equation, he assumed a mild slope of the bottom $\nabla$h/kh << 1 (where $\nabla$ is the horizontal gradient operator, k is the wavenumber, and h is the water depth) and thus neglected second-order bottom effect terms proportional to O($\nabla$h)$^2$ and O($\nabla$$^2$h). (omitted)

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Reduction of the Foam Generated in the Discharge Channel of a Power Plant (발전소 배수로에서 발생하는 거품 저감 방법)

  • Oh, Young-Min;Oh, Sang-Ho;Jang, Se-Chul
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.4
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    • pp.235-240
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    • 2010
  • The foam produced by the effluent cooling water which is released to the discharge channel provokes civil complaints due to the visual pollution to the neighboring residents. In this study, a physical model test was conducted by placing tetrapods on the bottom slope of the discharge channel in order to suggest an effective method of reducing the amount of generated foam. Field application of the main results of the model test showed qualitatively apparent reduction of the foam generation at the discharge channel.

Model Parametrization on the Mixing Behavior of Coastal Discharges

  • Kim, Jong-Kyu
    • Journal of Ocean Engineering and Technology
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    • v.17 no.2
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    • pp.1-7
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    • 2003
  • A common feature in the three-dimensional numerical model experiments of coastal discharge with simplifed model and idealized external forcings is investigated. The velocity fields due to the buoyancy and flow flux, are spreaded radiately and the surface velocites are much greater than homegeneous discharges. The coastal dischargd due to the Coriolis force and flow flux are shaped a anticyclical gyre (clockwise) and determined the scale of the gyre in the coastal zone, respectively. The bottom topography restricts a outward extention of the coastal fronts and it accelerates a southward flow.

Total Phenolic Contents and Biological Activities of Korean Seaweed Extracts

  • Kim, So-Jung;Woo, Seon-Ock;Yun, Hee-Young;Yum, Seung-Shic;Choi, Eun-Seok;Do, Jeong-Ryong;Jo, Jin-Ho;Kim, Dong-Giun;Lee, Suk-Chan;Lee, Taek-Kyun
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.798-802
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    • 2005
  • Crude extracts of thirty seaweeds collected in Korea were obtained using 50% ethanol, and total phenolic contents and antioxidant activities were compared. Two brown algae, Ecklonia cava (E. cava) and Sargassum siliquastrum (S. siliquastrum), showing high antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide anion radical scavenging activity were further investigated for their inhibitory effects on tyrosinase activity. The E. cava extract had the highest total phenolic content among the seaweeds extracts. Total phenolic contents were strongly correlated with antioxidant activity in the thirty seaweed extracts ($R^2\;=\;0.9169$). The E. cava and S. siliquastrum extracts exhibited higher inhibition to tyrosinase activity than butylated hydroxytoluene (BHT) and epigallocatechin gallate (EGCG).

Diagnosis for Status of Dredging and Ocean Disposal of Coastal Sediment in Korea (우리나라 연안준설 및 준설토 해양투기 현황 진단)

  • Eom, Ki-Hyuk;Lee, Dae-In;Park, Dal-Soo;Kim, Gui-Young
    • Journal of Environmental Impact Assessment
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    • v.18 no.3
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    • pp.185-193
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    • 2009
  • This study documented and diagnosed the status and problems of coastal dredging and offshore disposal of dredged sediments in South Korea to improve assessment procedures for marine environmental impacts and develop effective management systems. A total of $729({\times}10^6)m^3$ of coastal sediment was dredged in the harbors during the period of 2001-2008. Most of dredged sediment was disposed to the land dumping sites whereas ocean disposal accounted for less than 5%. Ocean disposal areas were especially concentrated to the exclusive economic zone (EEZ) in the southeast of Busan, which is not only an important fishing area for fishermen, but also considered to be spawning and nursery ground for some commercial fish species. To minimize negative impacts of dredging and ocean disposal of coastal sediment on marine ecosystem and potential strife among coastal users, we suggest 1) in development projects involving ocean disposal, it should be mandatory to propose careful reuse plans in the land, and 2) guidelines of environmental assessment and consequence management programs should be developed and implemented.