• Title/Summary/Keyword: tidal level

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The Effect of Position on Measured Lung Capacity of Patients with Spinal Cord Injury (척수손상환자의 폐활량에 자세가 미치는 영향)

  • Kim, Myoung-Kwon;Hwangbo, Gak
    • Proceedings of the Korea Contents Association Conference
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    • 2012.05a
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    • pp.173-174
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    • 2012
  • To determine whether position affects measured lung capacity of spinal cord injury patients. The study subjects were 45 patients with spinal cord injury (cervical level 15, thoracic level 15, lumbar level 15). Subjects were provided with a full explanation of the experimental procedures and all provided written consent signifying their voluntary participation. We used a spirometer (Spirometer, Micromedical Ltd, UK) to measure pulmonary function in the supine and sitting positions (straightened upper body at an angle of $90^{\circ}$). Forced vital capacity (FVC), forced expiratory volume during the first second (FEV1), tidal volume (TV), and maximum insufflation capacity (MIC) were also measured. FVC, FEV1, TV, MIC (%) were greater in the supine than in the sitting position for those with injury at the cervical or thoracic injury level. On the other hand, FVC, FEV1, TV, MIC (%) were lower in the supine position for those with an injury at the lumbar level. More attention should be paid to the effect of injury level on measured lung capacity.

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Performance Evaluation of Ocean Small Hydropower Plant by Analyzing Water Level and Flow Rate of Circulating Water (방류수의 수위 및 유량 분석을 통한 해양 소수력 성능평가)

  • Kang, Keum-Seok;Kim, Ji-Young;Ryu, Moo-Sung
    • New & Renewable Energy
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    • v.5 no.3
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    • pp.32-39
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    • 2009
  • The Samcheonpo ocean small hydropower plant (SHP) has a special feature of using marginal hydraulic head of circulating water system of fossil fuel power plant as a power source and having the characteristics of general hydropower generation and tidal power generation as well. Also, it contributes to reducing green house gases and developing clean energy source by recycling circulating water energy otherwise dissipated into the ocean. The efficiency of small hydropower plant is directly affected by effective head and flow rate of discharged water. Therefore, the efficiency characteristics of ocean hydropower plant are analyzed with the variation of water level and flow rate of discharged water, which is based on the accumulated operation data of the Samcheonpo hydropower plant. After the start of small hydropower plant operation, definite rise of water level was observed. As a result of flow pattern change from free flow to submerged flow, the instability of water surface in overall open channel is increased but it doesn't reach the extent of overflowing channel or having an effect on circulation system. Performance evaluation result shows that the generating power and efficiency of small hydropower exceeds design requirements in all conditions. Analysis results of CWP's water flow rate verify that the amount of flowing water is measured less and the highest efficiency of small hydropower plant is achieved when the effective head has its maximum value. In conclusion, efficiency curve derived from water flow rate considering tidal level shows the best fitting result with design criteria curve and it is verified that overall efficiency of hydropower system is satisfactory.

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Short-term Variation in Species Composition of Surf-zone Fishes at Daechon Beach, the Yellow Sea of Korea (대천 해빈 쇄파대어류 종조성의 단기 변화)

  • Lee, Tae-Won
    • Korean Journal of Ichthyology
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    • v.13 no.1
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    • pp.32-39
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    • 2001
  • Surf-zone fishes in Daechon Beach, situated at the mouth of Cheonsu Bay, Korea, were collected by a beach seine during the spring and neap tides in August 1999. Short-term variation in species composition was analyzed based on tidal range, tidal level, and time of day. Of 24 species identified, juvenile pelagic fishes predominated in the number of individuals captured. Wilcoxon signed-rank test revealed that the number of individuals was significantly higher during the spring tide than during the neap tide. During the spring tide the fishes were more abundant at the low level than at the high level, while during the neap tide there was no significant difference. The mean density of pelagic fishes did not show significant differences between high and low tides. Demersal fishes were caught mainly in the water below the low level of the neap tide.

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Sediment Distribution of the Yeosu Sound on the Southern Coast of Korea Based on the 3.5 kHz Profiles (3.5 kHz 지층단면도에 나타난 여수해만의 퇴적물 분포)

  • 오진용;이연규;윤혜수;김성렬;최정민
    • Economic and Environmental Geology
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    • v.33 no.5
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    • pp.425-434
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    • 2000
  • The 3.5 KHz seismic survey was carried out for studying the distribution pattern of the unconsolidated sediments of the Yeosu Sound on the southern coast of the Korean Peninsula. Field data originally recorded in analog are converted and processed digitally to recover the high-resolution acoustic profiles. Across the north-south trending channel with the depth of 20~30 m, different seismic facies types are observed in the top section of sediments. The western part is characterized by the continuous high-amplitude subparallel reflectors within which the acoustic turbidity as a token of the presence of gas is commonly observed, whereas the counterpart largely shows poor reflectors and has shallow acoustic basement toward the north. The dissimilarity of the seismic expression across the channel can be interpreted as the result of the change of depositional environment caused by relative sea-level fluctuations of the late-Quaternary. During the last glacial period, the Yeosu Sound was exposed and eroded by the paleo-Seomjin River. By the following rapid rise of sea level, it was covered by the transgressive sand sheet. When the sea level reached near the present position, the muddy sediment has accumulated only in the western part of the Yeosu Sound as its depositional front has moved toward the north. It is partly caused by the asymmetrical tidal current in the Yeosu Sound where the flood near the bottom has stronger current flow and contains more suspended sediments.

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Numerical Modeling of Storm Surge around the Coast of Pusan (부산연안 폭풍해일 변동양상과 수치예측)

  • 이종섭;주귀홍;장선덕
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.2 no.2
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    • pp.104-111
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    • 1990
  • The water level variation due to the Typhoon around the coast of Pusan in the southern sea of Korea is investigated from the observed tidal record. Water level variations at six stations along the coast are discussed in association with the meteorological data. The characteristics of storm surge at Pusan during Typhoon Thelma in 1987 is analysed using the observed data, and it is performed the numerical simulation of storm surge which includes a inverse barometric effect due to the horizontal distribution of sea sur-face pressure. From the calculation results, the peak value of storm surge in the coast of Pusan was occur-red around the 01:00 July 16th, which is well coincident with the observed water level variation at the Kadukdo. However, the calculated value at the Pusan TBM is inconsistent with the observed one, which is regarded due to a reason that the Tidal Bench Mark (TBM) locates in the channel. In the computation results, the maximum surge occurs at the coast of Nakdong estuary, which is considered primarily due to a topographic effect, and water level variation exceeded 2.5 meter in these areas while only about 60 cm in another coasts.

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The evaluation of pollution level and release characteristics by inner productivity in the sediment of lake (호소 퇴적물 내부생산성 오염도 영향 평가 및 용출특성에 관한 연구)

  • Lee, Sang Eun;Choi, I Song;Lee, Sang Keun;Lee, In Ho;Oh, Jong Min
    • Journal of Environmental Impact Assessment
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    • v.21 no.1
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    • pp.81-91
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    • 2012
  • In this study, it is grasped the status of nutrients through an investigation of release characteristics and physicochemical properties of sediments on reservoir. And then the effect of sediments is evaluated on the water quality in reservoir. In the results of physicochemical analysis, the pollution level of midstream is the highest, which shows the traits that the water is more deeper and takes place a deposition consistently. Then, the pollution level of upstream is higher than downstream's because inflow has influence on the upstream directly. The downstream is located near tidal gate so that the soil particles can be moved easily and are difficult to be deposited due to the distribution of seawater by control of tidal gate. Therefore, the downstream is showed the lowest pollution level than the others. Also, the concentration of SOD(Sediment Oxygen Demand) in the upstream which is influenced on the effect of inflow is highest than the others. When it analyzes under anaerobic and aerobic condition to understand the release characteristic of sediment, it shows that the release rate is low or negative under the aerobic condition. Whereas the release rate is usually positive under the unaerobic condition relatively. According to these results, it is necessary to maintain the proper environmental factors of water body for decreasing the release rate of sediment. Because the release rate is changeable under the different condition of water body. Therefore, proper strategies are required for increasing the self-purification of water as well as keeping the aerobic condition of sediment and managing a sediment layer directly to control the inner-pollution by the sediment of reservoir.

Late Quaternary Sequence Stratigraphy in Kyeonggi Bay, Mid-eastern Yellow Sea (황해 중동부 경기만의 후기 제4기 순차층서 연구)

  • Kwon, Yi-Kyun
    • Journal of the Korean earth science society
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    • v.33 no.3
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    • pp.242-258
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    • 2012
  • The Yellow Sea has sensitively responded to high-amplitude sea-level fluctuations during the late Quaternary. The repeated inundation and exposure have produced distinct transgression-regression successions with extensive exposure surfaces in Kyeonggi Bay. The late Quaternary strata consist of four seismic stratigraphic units, considered as depositional sequences (DS-1, DS-2, DS-3, and DS-4). DS-1 was interpreted as ridge-forming sediments of tidal-flat and estuarine channel-fill facies, formed during the Holocene highstand. DS-2 consists of shallow-marine facies in offshore area, which was formed during the regression of Marine Isotope Stage (MIS)-3 period. DS-3 comprises the lower transgressive facies and the upper highstand tidal-flat facies in proximal ridges and forced regression facies in distal ridges and offshore area. The lowermost DS-4 rests on acoustic basement rocks, considered as the shallow-marine and shelf deposits formed before the MIS-6 lowstand. This study suggests six depositional stages. During the first stage-A, MIS-6 lowstand, the Yellow Sea shelf was subaerially exposed with intensive fluvial incision and weathering. The subsequent rapid and high amplitude rise of sea level in stage-B until the MIS-5e highstand produced transgressive deposits in the lowermost part of the MIS-5 sequence, and the successive regression during the MIS-5d to -5a and the MIS-4 lowstand formed the upperpart of the MIS-5 sequence in stage-C. During the stage-D, from the MIS-4 lowstand to MIS-3c highstand period, the transgressive MIS-3 sequence formed in a subtidal environment characterized by repetitive fluvial incision and channel-fill deposition in exposed area. The subsequent sea-level fall culminating the last glacial maximum (Stage-E) made shallow-marine regressive deposits of MIS-3 sequence in offshore distal area, whereas it formed fluvial channel-fills and floodplain deposits in the proximal area. After the last glacial maximum, the overall Yellow Sea shelf was inundated by the Holocene transgression and highstand (Stage-F), forming the Holocene transgressive shelf sands and tidal ridges.

Growth and Yield of Rice as Affected by Nitrogen Level and Split-Application Method in the Puddled Drill Seeding in Tidal Land Paddy Field (염해답(鹽害畓)에서 벼 무논골뿌림재배시(栽培時) 질소시비량(窒素施肥量) 및 분시방법(分施方法)에 따른 생육(生育)과 수량성(收量性))

  • Shin, Bog-Woo;Yoo, Chul-Hyun;Choi, Song-Yeol;Jeong, Ji-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.29 no.3
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    • pp.264-269
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    • 1996
  • Four leavels of nitrogen and five split-application method were investigated in the puddled drill seeding of rice in tidal land paddy field of Munpo series in Gyehwado. Soil ammonium concentration increased of higer nitrogen level, and was higher in latex coated urea(LCU) than urea split-application, and stage of $NH_4-N$ was the higher in maximum tillering stage. Rice yield, nitrogen availability and yield increment rate according to nitrogen levels were the highest when nitrogen was applied 200kg/ha and also it were the highest in the LCU application by 30% decreased than urea application as affected by application method. Adequate application amount of nitrogen was estimated 222kg/ha in direct drill seeding of rice in tidal land paddy field.

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Nutrient Value and Yield Response of Forage Crop Cultivated in Reclaimed Tidal Land Soil Using Anaerobic Liquid Fertilizer (간척지 토양에서 혐기소화액비 시용에 따른 사료작물의 생산성과 사료가치 평가)

  • Shin, Kook-Sik;Hwang, Won-Jae;Lee, Seung-Heon;Kim, Chang-Hyun;Yoon, Young-Man
    • Korean Journal of Organic Agriculture
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    • v.20 no.4
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    • pp.669-685
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    • 2012
  • This study was carried out to investigate the nutrient value and yield response of corn, barley, and sudangrass by the application of anaerobic liquid fertilizer in two tidal land soil in order to design the resource recycling agricultural system between livestock and forage crop cultivation in a environment friendly agricultural region. Forage crop yields at reclaimed tidal soil during were at the level of 64~76% comparing with forage crop yields at upland soil in the cropping system of corn, barley, and sudangrass. And yields of forage crops were in the order of barley > corn > sudangrass in the cultivated cropping system for 2 year. Relative feed values (RFVs) of forage crops were 88%~106% for corn, 90%~111% for barley, and 91%~113% for sudangrass, and the carrying capacity of beef cattle (Hanwoo) was 5.8~8.6 head/year/ha for the corn-barley cropping system of one year, and 4.8~6.7 head/year/ha for the barley-sudangrass cropping system of one year. Also, carrying capacity of beef cattle (Hanwoo) was highest in the application level of anaerobic liquid fertilizer 200%.

Characteristics of vegetation succession on the Pinus thunbergii forests in warm temperate regions, Jeju Island, South Korea

  • Hong, Yongsik;Kim, Euijoo;Lee, Eungpill;Lee, Seungyeon;Cho, Kyutae;Lee, Youngkeun;Chung, Sanghoon;Jeong, Heonmo;You, Younghan
    • Journal of Ecology and Environment
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    • v.43 no.4
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    • pp.438-453
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    • 2019
  • Background: To investigate the trends of succession occurring at the Pinus thunbergii forests on the lowlands of Jeju Island, we quantified the species compositions and the importance values by vegetation layers of Braun-Blanquet method on the Pinus thunbergii forests. We used multivariate analysis technique to know the correlations between the vegetation group types and the location environmental factors; we used the location environment factors such as altitudes above sea level, tidal winds (distance from the coast), annual average temperatures, and forest gaps to know the vegetation distribution patterns. Results: According to the results on the lowland of Jeju Island, the understory vegetation of the lowland Pinus thunbergii forests was dominated by tall evergreen broad-leaved trees such as Machilus thunbergii, Neolitsea sericea, and Cinnamomum japonicum showing a vegetation group structure of the mid-succession, and the distribution patterns of vegetation were determined by the altitudes above sea level, the tidal winds on the distance from the coast, the annual average temperatures, and the forest gaps. We could discriminate the secondary succession characteristics of the Pinus thunbergii forests on the lowland and highland of Jeju Island of South Korea. Conclusions: In the lowland of Jeju Island, the secondary succession will progress to the form of Pinus thunbergii (early successional species)→Machilus thunbergii, Litsea japonica (mid-successional species)→Machilus thunbergii (late-successional species) sequence in the temperate areas with strong tidal winds. In the highland of Jeju Island, the succession will progress to the form of Pinus thunbergii (early successional species)→Neolitsea sericea, Eurya japonica (mid-successional species)→Castanopsis sieboldii (late-successional species) sequence in the areas where tidal winds are weak and temperatures are relatively low. However, local differences between lowland and highland of Jeju Island will be caused by the micro-environmental factors resulting from the topographic differences and the supply of tree seeds. From the characteristics of succession study, we could properly predict and manage the Pinus thunbergii forest ecosystem on lowland and highland of Jeju Island.