• Title/Summary/Keyword: Tide effect

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연약지반 변형해석을 위한 다목적 Program개발

  • 박병기;정진섭
    • Proceedings of the Korean Geotechical Society Conference
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    • 1991.10a
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    • pp.362-375
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    • 1991
  • Background and Necessity of the study : For more than 20 years, the soil engineering reserach group of Chonnam National University has been performing the deformation analysis of soft clayey foundation, since the University is located near the south-western coast of Korean Peninsulla, along which tide reclamation works have been under proaressing. Associsted with the fact mentioned above, the researchers have been developing a computer program in order to carry out deformation analysis of soft foundation since early 1980. Case-studies : In this research, the Biot's equation was selected as the governing equation coupled with several constitutive models including original and modified Cam-clay models, elasto-viscoplastic model, Lade's model etc. The anisotropy of soi1 can be considered in this program. To validate the accuracy of the computer program developed a couple of case-studies were performed. These include the pilot banking, sand drain considering smear effect and compound foundation reinforced with sheet pile into soft foundation.i) The pilot banking Good results could be acquired by assuming banking load as the body force composed of finite element mesh rather than equivalent concentrated load.ii) The sand drain Due to smear, the delay of consolidation was remarkable at the early stsge. so safety for the failure of foundation should be checked for the initial step of consolidation. iii) The compound foundation Accurate results were obtained by introducing the joint element method for the soft foundation reinforced with sheet pile into soiㅣ.

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Antiobesity Effect of Recombinant Human Caseinomacropeptide tide in Sprague-Dawley Rat

  • Kim Yu-Jin;Oh You-Kwan;Yoo Seung-Shick;Park Kun-Young;Kang Whankoo;Park Sunghoon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.3
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    • pp.242-247
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    • 2005
  • Caseinomacropeptide (CMP) is a glycopeptide of 64 amino acid residues derived from the C-terminal of mammalian milk K-casein. Recently, human CMP (hCMP) was produced from the recombinant yeast Saccharomyces cerevisiae. In this study, the antiobesity activity of the recombinant hCMP (rhCMP) was investigated in vivo using Sprague-Dawley rats. The rhCMP did not affect the rats fed with a normal fat diet (fat content, $5.0\%$), but decreased the body weight gain of the rats fed with a high fat diet (fat content, $20\%$) by up to $19\%$. Autopsies revealed that the weights of the liver, kidney and adipose tissues decreased when the rats were given the rhCMP, which also reduced the lipid concentrations in the plasma and liver, but enhanced the fecal excretion of lipids. These results suggest that rhCMP prevent the accumulation of lipid by stimulating its fecal excretion, so could be used as a food supplement to alleviate the obesity problem caused by a high fat diet.

The Change of Beach Processes at the Coastal Zone with the Impact of Tide (조석(潮汐)의 영향(影響)이 있는 연안(沿岸)해역(海域)에서의 해안과정(海岸過程)의 변화(變化))

  • Kim, Sang-Ho;Lee, Joong-Woo
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.05a
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    • pp.257-262
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    • 2002
  • Numerical model introduced in this study combines wave refraction-diffraction, breaking, bottom friction, lateral mixing, and critical shear stress and three sub-models for simulating waves, currents, and bottom change were briefly discussed. Simulations of beach processes and harbor sedimentation were also described at the coast neighboring Bangpo Harbor, Anmyundo, Chungnam, where the area has suffered from accumulation of drifting sand in a small fishing harbor with a wide tidal range. We also made model test for the case of a narrow tidal range at Nakdong river's estuary area to understand the effect of water level variation on the littoral drift. Simulations are conducted in terms of incident wave direction and tidal level. Characteristics of wave transformation, nearshore current, sediment transport, and bottom change are shown and analyzed. We found from the simulation that the tidal level impact to the sediment transport is very important and we should apply the numerical model with different water level to analyze sediment transport mechanism correctly. Although the model study gave reasonable description of beach processes and harbor sedimentation mechanism, it is necessary to collect lots of field observation data, including waves, tides and bottom materials, etc. for better prediction.

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Changes in Benthic Macrofauna of the Saemangeum Tidal Flat as Result of a Drastic Tidal Reduction (급격한 조석 감소에 의한 새만금 갯벌 대형저서동물 변화)

  • Koo, Bon-Joo;Shin, Sang-Ho;Lee, Seok
    • Ocean and Polar Research
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    • v.30 no.4
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    • pp.485-495
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    • 2008
  • Tidal ranges of inner Saemangeum were largely reduced after the final dyke enclosure, resulting in the former tidal flats becoming either permanently exposed, still influenced by changing tide, or permanently submerged. The effect of reduced tidal range on survival and population stability of tidal flat macrofauna were investigated at three shifted habitats after the dyke completion. At the exposed area, several species survived for 80 days after the dyke enclosure. However, within 120 days, all macrofauna died off due to the elevated temperature during summer. At the intertidal area, some species were maintained until 170 days after the dyke enclosure with a large decrease of the faunal abundance. Species of the submerged area were seen to be more tolerant of the changed environments. The opportunistic species, such as Sinocorophium sinensis, Theora fragilis and Pseudopolydora Kempi, were massively introduced into the submerged area after the dyke enclosure, in which the benthic ecosystem was severely disturbed.

Circulation in the Central South Sea of Korea in Spring 1999

  • Lee, Jae-Chul;Lee, Sang-Ho;Kim, Dae-Hyun;Son, Yong-Tae;Perkins, Henry-T.;Kim, Jeong-Chang;Pang, Ig-Chan
    • Journal of the korean society of oceanography
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    • v.38 no.3
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    • pp.143-155
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    • 2003
  • Current and sea level were observed in spring 1999 by a bottom mounted ADCP and tide gauge in the central part of the South Sea of Korea. With respect to the front, the distribution of isotherms is prograde in the offshore region whereas that of isohalines is retrograde, especially in the coastal area. The combined effect results in shoaling of isopycnals at the front. This distribution corresponds to a westward coastal flow on the northern side of the front and the eastward Tsushima Warm Current (TWC) to the south, determined by vessel-mounted ADCP observations. The low-frequency current shows either alternating clockwise-counterclockwise rotation or else persistent eastward motion depending on the frontal motion. Fluctuations of wind, sea level and current are coherent at period of 3-4 days and show some characteristics of Ekman-like dynamics.

A Study on the Luring of fish Shoals into the Fyke net by the Underwater Sound Emission (제주도 연안의 각망어업에 있어서 수중음악에 의한 어군의 유집에 관한 연구)

  • Abn, Jang-Yong;Seo, Du-Ok;Kim, Sam-Kon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.1
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    • pp.50-58
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    • 1996
  • The authors carried out a field experiment to confirm the effect of underwater sound on the luring of fish schools in a setnet in the coast of Cheju Island. The effects of the acoustic emission on the luring of fish schools were observed using a manufectured underwater speaker in the setnet, and pure sound, of which frequency was 600Hz and the source level was 126dB, was emitted on and off at 5 minutes intervals in the set net during the night of ,July 29 and ,July 31. So we had recorded behavior of fish schools by the telesounder with two channel and shape of the setnet by underwater video camera and analyzed them. When the flood and ebb currents were around the setnet, the nets rised to the surface of water and it happened occasionaly at the stand of tide. Therefore, it was in the state that fish schools feel constraint to enter into the setnet, and was required a new design of the setnet stand up to strong tidal current. As the pure sound, of which frequency was 600Hz was emitted for the luring of fish schools in a setnet, the catch ammounts of fish, the young horce mackereWI'rachllrlls japonicus), was increased 4~6 times than not emitted.

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Calculation of Generation Power Integrating Sihwa Tidal Power into Power Systems (시화조력발전 계통연계에 따른 시간대별 발전량 산정)

  • Kim, Kyu-Ho;Song, Kyung-Bin
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.1
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    • pp.157-163
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    • 2007
  • This paper presents a method to calculate generation power for integrating Sihwa tidal power into power systems. The sea levels of 1 minute interval using cubic interpolation based on the forecasted levels of high and low water offered from Nori(National Oceanographic Research Institute) are calculated. If the sea level is greater than the lake level and the difference between sea level and lake level at high tide is over the default value, it begins to calculate the tidal power. It is seen that tidal power can supply power to demand side stably and economically from assessment of effect for integrating tidal power into power systems.

GLOBAL MONITORING OF PLANKTON BLOOMS USING MERIS MCI

  • Gower, Jim;King, Stephanie;Goncalves, Pedro
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.441-444
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    • 2006
  • The MERIS MCI (Maximum Chlorophyll Index), measuring the radiance peak at 709 nm in water-leaving radiance, indicates the presence of a high surface concentration of chlorophyll ${\underline{a}}$ against a scattering background. The index is high in 'red tide' conditions (intense, visible, surface, plankton blooms), and is also raised when aquatic vegetation is present. A bloom search based on MCI has resulted in detection of a variety of events in Canadian, Antarctic and other waters round the world, as well as detection of extensive areas of pelagic vegetation (Sargassum spp.), previously unreported in the scientific literature. Since June 1 2006, global MCI composite images, at a spatial resolution of 5 km, are being produced daily from all MERIS (daylight) passes of Reduced Resolution (RR) data. The global composites significantly increase the area now being searched for events, though the reduced spatial resolution may cause smaller events to be missed. This paper describes the composites and gives examples of plankton bloom events that they have detected. It also shows how the composites show the effect of the South Atlantic Anomaly, where cosmic rays affect the MERIS instrument.

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Methodology for Risk Assessment for Exposure to Hurricane Conditions

  • Edge, Billy L.;Jung, Kwang-Hyo
    • International Journal of Ocean System Engineering
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    • v.2 no.1
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    • pp.37-49
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    • 2012
  • An analysis of potential flooding by storm surge and wave run-up and overtopping can be used to evaluate protection afforded by the existing storm protection system. The analysis procedure can also be used to evaluate various protection alternatives for providing typhoon flood protection. To determine risk, the storm surges for both historical and hypothetical are compiled with tide conditions to represent high, slack and low water for neap, spring and mid range tides to use with the statistical procedure known as the Empirical Simulations Technique (EST). The EST uses the historic and hypothetical events to generate a large population of life-cycle databases that are used to compute mean value maximum storm surge elevation frequency relationships. The frequency-of-occurrence relationship is determined for all relevant locations along the shoreline at appropriate locations to identify the effect using the Empirical Storm Simulation (EST). To assist with understanding the process, an example is presented for a study of storm surge analysis for Freeport, Texas. This location is in the Gulf of Mexico and is subject to hurricanes and other tropical storms that approach from the Atlantic Ocean.

Liquifaction Evaluation of Saemangeum Area and the Considerations of Liquifaction Effect to the Foundations of Structures in Near Future (I) (새만금 지역의 액상화 평가 및 향후 구조물 기초 설계시 액상화 영향의 고려방안 (I))

  • Kim, You-Seong;Ko, Hyoung-Woo
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.2
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    • pp.91-100
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    • 2011
  • This study presents the estimation for the possibility of liquefaction according to the liquefaction evaluation methods in Saemangeum reclamation area for tide embankment, Jeollabuk-do, Korea. Liquefaction estimation is performed by cyclic triaxial tests and seismic response analysis using earthquake records of the long- and short-term. This area appears to have greatly potential of liquefaction from the grain-size distribution curve of the dredged and reclaimed soil in the area. Because the liquefaction can occur in this area if the foundations or buried structures are built at a depth within 10m below ground surface, the meticulous care is required in the design of them in the future.