• Title/Summary/Keyword: tidal difference

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A Calculation of Agricultural Water Demand According to the Farmland Developing Plan on the Saemangeum Tidal Land Reclamation Project (새만금 간척지구의 농업용지 토지이용계획을 고려한 농업용수 수요량 산정)

  • Jang, JeongRyeol;Lee, SungHack;Cho, Youngkweon;Choi, JinYong
    • KCID journal
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    • v.21 no.1
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    • pp.1-16
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    • 2014
  • The purpose of this study is to calculate agricultural water demand as considering landuse plan of the farm land on the Saemangeum tidal land reclamation project. This study based on the farm landuse plan(2012) and considered some items which did not included previous work like prevention water for resalinization for paddy and upland and muli-purpose water for upland. This study showed that the agricultural water demand estimated $145.123Mm^3/yr$, which is needed as much $14.792Mm^3/yr$ as more water than previous work. The difference comes from the change of unit water demand. Water demand is possible to be changed if guidelines are improved and detailed design work is completed through further study. Especially, the more studies for prevention water for resalinization in a tidal reclaimed farmland and water demand for a horticulture are needed.

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Analysis of Electrical Conductivity during the Growing Period in Saemangum Recaliamed Tidal Lands (새만금 간척지토양의 벼생육과정중 전기전도도 분석)

  • Son, Jae-Gwon;Choi, Jin-Kyu;Koo, Ja-Woong;Song, Jae-Do;Kim, Young-Joo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.79-82
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    • 2003
  • This study was performed in order to analyze the changes of electrical conductivity during the growing period in Saemangum reclaimed tidal lands soils. According to USDA Salinity Laboratory classification system of salt affected soils, the reclaimed tidal land soils used in this study were saline-sodic soils. As the results obtained from analying the changes of electrical conductivity(EC) during the growing period in reclaimed tidal land soils, EC of irrigation water and soils were no difference among the fertilization quanity, fertilization method and fertilization times.

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Estimation of Time Mean Velocities from NOAA Satellite 557 Data (NOAA위성의 557자료를 이용한 시간평균유속의 추정)

  • 이태신;정종률
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.7 no.3
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    • pp.241-247
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    • 1995
  • A time mean surface velocity field was estimated from AVHRR/SST in the Korea Strait. Time duration of SST data set was not different from tidal period and tidal elimination was investigated. The velocity field was estimated by inverse method and compared with results of ADCP observation and results of Odamaki(1989). In accordance with results. tidal component was eliminated partially in case that there were a little difference between total time interval of 557 data set and tidal period.

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Study on the Estimation of Discharge Coefficient of Sluice for Tidal Power Generation by Performing Physical Experiment (수리실험에 의한 조력발전용 수문의 유량계수 산정에 관한 고찰)

  • Oh, Sang-Ho;Lee, Kwang Soo;Lee, Dal Soo;Jang, Se-Chul
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.160.1-160.1
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    • 2011
  • In this study, the influence of methodology of assessing water levels on the discharge coefficient of sluice for tidal power generation was investigated. A physical experiment was performed in a planar open channel by installing 1/70 scale model of the sluice caisson in the planar open channel. In front of and behind the sluice model, sloping bathymetry was made to reproduce corresponding field condition. By analyzing the experimental results, it was found that the location of measuring water levels significantly affects the estimates of the discharge coefficient, due to the variability of the parameter according to the head difference between the measuring locations. Therefore, it is necessary to be careful in estimating and utilizing the discharge coefficient in the relevant study of a tidal power generation.

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Community Structure of the Ecosystem on the Intertidal Zone and Grass Land in Cheju Island - Distribution and Community Structure of Benthic Macroinvertebrates- (제주도 조간대 및 초지대 생태계의 군집구조에 관한 연구 -저서 대형무척추동물의 분포와 군집구조-)

  • 이정재;장익창;조운삼
    • The Korean Journal of Malacology
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    • v.5 no.1
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    • pp.10-28
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    • 1989
  • A study on the distribution and community structure of benthic macroinvertebrates on the intertidal zone of Cheju Island was carried out from June 1988 to May 1989. The macroinvertebrates collected and identified were composed of 7 phyla, 14 classes, 29 orders, 71 families and 135 species in this study. The dominant species of the upper tidal zone were Nodilittorina granularis and Heminerita japonica, those of the middle tidal zone were Monodonta neritoides and Lunella coronata coreensis, However, Monodonta neritoides and Chlorostoma arhyrostoma lischkei were dominant in the lower tidal zone. Community dominant indices were significantly high in the upper tidal zone. Macuoinvertebrates species which have the ability of resistance to the physical factors such as, strong waves and exposure to the hot sunlight were mainly distributed on the intertidal zone of Cheju Island. The difference in the number of species among seasons was not significant, but thao among zones was quite apparent and the lower the zone, the more abundant.

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Simulation of Tidal Fields around a Huge Floating Marina using a Multi-level Method

  • BOO SUNG YOUN
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.11a
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    • pp.114-119
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    • 2004
  • Floating marina has been interests as an alternative to the facilities for recreational boats because of its cost effectivenes and less environmental conflicts. For tile present research, a square floating marina with a length of 400m and draft of 5m was used. This marina can be extended to 800m by putting anotjer one together. Tidal field around tile marina was simulated using a multi-level finite difference method. Tidal motion was assumed sinusoidal in a closed rectangular bay. Velocities and residual current were investigated for two cases of single marina and two marinas installed in tile bay. It was found that the horizontal velocity fields from the water surface to the structure bottom around tile marina were affected. In the marina basin, magnitude of velocity was reduced considerably but overall quality of water circulation was preserved even after two marina were installed.

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A study on characteristics of seadike settlement according to the change of tidal level (조위 변화에 따른 제체의 침하 특성에 관한 연구)

  • Yoo, Hyun-Gu;Kim, Jong-Yun;Yoon, Myung-Seok;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1029-1036
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    • 2009
  • Seapage condition by sea water may appears on sea dike due to the gap of tidal, which generated by the sealevel repeatedly moves up and down result of the change of tidal level. In this study, apparatus was developed to apply similitude after setting the critical section. It was found that the soil loss was dramatically increased by increasing hydraulic gradient step by step. Also, to understand the change of seadike which considered the changes of the change of tidal level and inside sealevel, it was executed the experiments which divided the sea level condition of inside by continually changes the sealevel difference which is outside of the high tide and ebb tide.

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The Development of Model to Calculate Maximum Power for Tidal Power Plant Operation (조력발전 운영을 위한 최대 발전량 산정 모델개발)

  • Oh, Min-Hwan;Kim, Hual-Soo;Kim, Jae-Hoon;Song, Gyu-Seok
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.505-508
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    • 2006
  • Recently, concern for tidal power is being increased by newly recycled energy. It is important to decide on the maximum power estimate operation and it's stop by applying the difference of water level between tide level and artificial reservoir for the administration of tidal development. For maximum output of power through turbine generator, administrative variables and process on efficiency of hydraulic turbine and inflow discharge of reservoir is quite complicated because it is run through the connection of discharge-gate and turbine On the development of this model, the administrative process is decided, Operation block is presented for it's maximum power estimate.

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The Cause of Abnormal Tidal Residuals Along the Coast of the Yellow Sea in November 2013 (황해연안의 2013년 11월 이상조위편차 발생 원인)

  • Kim, Ho-Kyun;Kim, Young Taeg;Lee, Dong Hwan
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.4
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    • pp.344-353
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    • 2016
  • The cause of abnormal tidal residuals was examined by analyzing sea levels, sea surface atmospheric pressures, winds at ten tide stations, and current, measured at the coast of the Yellow Sea from the night of November $24^{th}$ to the morning of the $25^{th}$ in 2013, along with weather chart. Additionally, the cross-correlations among the measured data were also examined. The 'abnormal tidal residuals' mentioned in this study refer to differences between maximum and minium tidal residuals. The largest abnormal tidal residual was identified to be a difference of 176 cm occurring over 4 hours and 1 minute at YeongJongDo (YJD) with a maximum tidal residual of 111 cm and minimum of -65 cm. The smallest abnormal tidal residual was 68 cm at MoSeulPo (MSP) during 8 hours 52 minutes. The cause of these abnormal tidal residuals was not a meteo-tsunami generated by an atmospheric pressure jump but wind generated by the pressure patterns. The flow speed due to these abnormal tidal residuals as measured at ten tide stations was not negligible, representing 16 ~ 41 % of the annual average ebb current speed. From the cross correlation among the tidal residuals, winds, and tidal residual currents, we learned the northern flow, due to southerly winds, raised the sea level at Incheon when a low pressure center located on the left side of the Korean Peninsula. After passing the Korean Peninsula, a southern flow due to northerly winds decreased the sea level.

A comparison of ventilation effects using bag-valve-mask assist device (백-밸브-마스크 보조장치를 이용한 환기효과 비교)

  • EunYoung, Seo;ByoungGil, Yoon;GaEun, Kim;YougSeok, Kim
    • The Korean Journal of Emergency Medical Services
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    • v.26 no.3
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    • pp.37-46
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    • 2022
  • Purpose: TThe experiment was designed to compare the efficiency of ventilation between conventional BVM ventilation and a newly devised A-BVM ventilation method with Tidal volume, total ventilation rate, average Ventilation speed, and average Ventilation volume. Methods: 40 Paramedical students who agreed to participate in the study were analyzed. Values were measured using IMB PASS after 2 minutes of Brayden Pro manikin with BVM and A-BVM ventilation. The difference in general characteristics was assessed by t-test and ANOVA and the difference in ventilation methods was analyzed by IBM SPSS. Results: A significant difference was found between the two ventilation methods in terms of tidal volume (t=-11.203, p<.001), ventilation time (t=-3.834, p<.001), and optimum ventilation probability (t=10.770, p<.001). A-BVM ventilation method, rather than BVM ventilation method, showed a value close to the appropriate amount recommended by Korean Advanced Life Support (500~600mL) in tidal volume, and higher in optimum ventilation probability. Conclusion: We could identify the a better mode of ventilation. Further studies on the efficacy of existing BVM ventilation methods as compared to device augmented BVM ventilation methods should be carried out to ensure that adequate ventilation is available to patients in clinical practice.