• 한국물환경학회지
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• 제21권4호
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• pp.360-367
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• 2005

We have performed to analyze the trophic state resulting of Lake Yongdam as a result of water quality and nutrient concentration. Lake Yongdam is artifitial multi-purpose Dam resulting from the floods of 2001. The water quality of Lake Yongdam may affect the status of the Geum river basin including the Daecheong reservoir. It is necessary to understand the trophic state to assess water quality until stability after flooding. Water quality was surveyed using depth and hydraulic condition analysis. Further density flow was estimated for stratification and trophic state of Lake Yongdam by chlorophyll ${\alpha}$ concentration (2001~2004). And Environmental factors on chlorophyll ${\alpha}$ concentration were analyzed statistically. Trophic state was evaluated as the oligotrophic state at the main stream of the reservoir and eutrophic state at the upper stream in 2001, but evaluated as eutrophic state in 2002 and 2003 by TSI of Aizaki. From the results of multiple regression analysis using stepwise method, chlorophyll ${\alpha}$ concentration was shown to be very significant when nutrient concentration is high upon initial filling of the Dam. Chlorophyll ${\alpha}$ concentration varied according to sample site, season and year. Concentration were high in the upper stream of Lake Yongdam 4, algae bloom in these watershed were affected by location and high nutrient levels in the summer season which have in turn increased phytoplankton bloom into the reservoir.

• Parasites, Hosts and Diseases
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• 제25권1호
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• pp.69-82
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• 1987

금강 상류 지역 주민들에 Metagonimus속 흡충이 만연되어 있음은 1980년이래 보고되어 있으나 아직도 그 흡충의 종(種)이 확정되지 못한 상태이다. 본 연구는 다슬기에서 유출된 cercaria, 어류에 기생된 피낭유충 및 실험적 종숙주에서 검출된 성충의 형태와 생태 등을 검토하였고 그 결과를 다음과 같이 요약한다. 1. 금강 상류 수통리, 무주삼거리 및 소천리 앞의 금강천에서 1,730개의 다슬기(Semisulcospira globus)를 채집하여 cercaria의 자연유출율과 종을 동정한 바 7.2%의 cercaria양성율과 5종을 동정하였고, 그 중에서 Metagonimus속 cercaria가 3.7%로 가장 많았다. 2. Metagonimus속 cercaria를 방출하는 다슬기의 수조에 금붕어와 같이 10일간 사육하고 그 후60일까지 금부어에서 피낭유충형성 실태를 관찰하였던 바 금붕어 105마리중 22.9%의 감염율을 보였고 비늘(13/3%)과 지느러미(86.7%)에 피낭유충이 형성되었으며 그 수는 적었다. 3. 대청호와 금강상류에서 채집한 어류에서 Metagonimus속 피낭유충의 기생 실태를 조사한 바 끄리는 전수가 감염되었고 어체당 피낭유충의 감염수(250~2,400개)도 가장 많았다. 갈겨니, 피라미, 모래무지 등도 상류산은 100% 감염되어 있었으나 대청호산은 기생율이 낮았고 각 어체별 피낭유충의 기생수도 적었다. 잉어와 붕어는 피낭유충의 기생율과 기생수도 매우 적었다. 어종별로 분리한 피낭유층은 형태학적 차이는 없었으며, 어체내의 기생부위는 섬진강산 은어를 제외하고 비늘에서만 검출도었다. 4. 끄리와 피라미 유래의 피낭유충은 흰쥐에 개에, 갈겨니, 모래무지, 금붕어 유래이 피낭유충은 흰주에만 각각 감염시켜 그 성충의 회수율과 종숙주 소장 부위별로 기생율을 관찰하였다. 개에서는 충체의 회수율(63.3~65.8%)이 대단히 높았으나 쥐는 어종별 피낭 유충원(源)에 따라 큰 차이(3.5~31.6%)를 보였다. 성충은 흰주의 소장 중.하부에 분포되어 있었고 소장상부에 기생된 충체를 발견할 수 없었다. 실험적으로 감염시킨 금붕어의 피낭유충도 동일한 결과이었으나 섬진강산 은어 유래의 피낭유충 감염 흰쥐는 그 소장 상부에도 성충이 분포(9.2%)로 되어 있었다. 개에서는 소장상부에 소수(5.4~10.2%) 분포되어 있었으나 소장 중부(57.7~81.9%)와 하부(7.9~36.9%)에 많았다. 5. 성충의 형태는 그 크기가 개와 흰주 숙주에 따른 차이가 있었으나 동일 숙주에서는 어종별 피낭유충에 따라 차이가 없었다. 모든 성충의 구흡반은 복흡반보다 작았다. 채 후부에 위치한 두 정소(精巢)는 전후로 약간 떨어져 비스듬히 기울어져 있었고 자궁은 두 정소 사이를 지나 전방에 위치한 정소를 한 바퀴 돌아서 상행하였고 난황선은 충체의 후부 정소 중간까지 분포되어 있었다. 6. 충란의 크기는 평균 $29.1{\times}17.3{\mu}m$였다. 이상의 결과를 종합컨대 금강 유역에 분포되어 있는 Metagonimus 흡충은 제등(1984a)가 주장하는 Metagonimus yokogawai, Miyata형으로 동정하였다.

• 물과 미래
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• 제35권5호
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• pp.21-30
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• 2002

The inflow into a multi-purpose dam reservoir contains many suspended solids from the upper stream during the rainy season. Concentrations of SS increased to 73.3 mg/l and the TP measurement increased to 0.09 mg/l during the rainy season in 1999. It was discovered that particles less than $10\;\mu\textrm{m}$ in size composed about 50% of the total amount. Some of these particles reduce the reservoir capacity and have an impact on water. In this study, the sediment depth at Daecheong multi-purpose dam was examined. Piston coring was performed at 9 locations At Hoenam 1 out of 9 locations examined showed maximum depth, which was 90 cm and at Muneui 3 showed the minimum depth, which was 35 cm. At Hoenam, the release rate of TN was found to be $62.14~84.72\;mg/\textrm{m}^2{\cdot}day$ in 1998. However, it was found to considerably reduced to $23.20\;mg/\textrm{m}^2{\cdot}day$ in 2001. The release rate of TP was measured at $13.02~14.38\;mg/\textrm{m}^2$.day at 1998, and it was reduced to $6.93mg/\;mg/\textrm{m}^2{\cdot}day$ in 2001.

• 한국토양비료학회지
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• 제45권5호
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• pp.690-697
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• 2012

Approximately 67% of the total land area of the Korea is covered by forest. Eutrophication, defined as the enrichment of waters beyond natural levels, principally by the nutrient phosphorus (P), is a serious cause of concern at the present time. The contribution of forestry to P loading in catchment waters has not been intensively studied in Korea, but is potentially important because forests are often located in near-pristine environments. Phosphorus is retained by most mineral soils and, as a consequence, losses are usually negligible. However, it is much more mobile in organic soils where it can be relatively easily leached or lost through surface runoff, as these soils have a low capacity to retain free phosphate. This report has been prepared to study the influence of arable land used for paddy, upland, and forestry on water quality in the basin of Daechung reservoir.

• 한국환경과학회지
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• 제25권3호
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• pp.405-415
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• 2016

We analyzed the micro-meteorological characteristics during typical steam fog over the Gumi Reservoir of Nakdong river with the field observation data for recent 2 year(1 April 2013~31 March 2015) collected by the national institute of meteorological research, KMA. Steam fog occur when the cold drainage flows over the warm water surface. As the sensible and latent heat from water are provided to the air, the instability of lower atmosphere is increased. The resultant vertical mixing of warm, moist air near water surface and cold air aloft causes the formation of status cloud. The convection strengthened by radiative cooling of the upper part of the stratus causes the fog to propagate downward. Also, the temperature at the lowest atmosphere is increased rapidly and the inversion near surface disappear by these processes when the fog forms. The increase of wind speed is observed because the downward transportation of momentum is caused by vertical mixing.

• 한국유체기계학회 논문집
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• 제2권2호
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• pp.39-45
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• 1999

Pumped-storage power plants pumps the water from the lower reservoir to the upper reservoir using the extra electric power at night and generates electric power in the daytime. Currently it tends to be a high-head large-capacity machine. In this paper, we developed the computer programs for vibration analysis of the pump/turbine and generator/motor rotor system considering electromagnetic force, hydrodynamic unbalance force, dynamic characteristics of guide bearings and add mass of water. This program was verified by applying it to the real model and calculating the critical speed, natural mode and unbalance response.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.250-254
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• 1998

Pump-storage power plants, which pumps water from the lower reservoir to the upper reservoir using the extra electronic power at night and generates the electronic power in the daytime, are more increasing. Currently it has a tendency to be high-head large-capacity machines. So in the processing of design, we need to know the vibration characteristics of pump-turbine shaft system sufficiently. In this paper, we developed the computer programs for analyzing pump-turbine shaft system considering magnetic force of generator, hydraulic force at runner, dynamic characteristics of guide bearings and the effect of add mass of water. And the superiority of this program was verified by applying it to the real model and calculating high quality critical speed, natural mode and unbalance response.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.169-178
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• 2006

The pumped-storage power system is the one of the hydroelectric power systems, generating electricity with hydraulic head difference. In this system, the electricity is produced during the hours of peak demand by using water that has been pumped into an upper reservoir from a lower reservoir during the hours of low demand. Generally, the system consists of an under-ground power house and tunnels such as the headrace, pressure, and tailrace tunnels. The Chungsong pumped-storage power station is the sixth one In the pumped-storage power station in Korea. Both the regional self-government and the population of chungsong -Goon had made a great effort to draw this power station construction into this area. The proposed Chungsong pumped-power station construction project was accepted by the central government as a part of the national electricity plan for the first time in Korea.

• 산업기술연구
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• 제27권A호
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• pp.77-83
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• 2007

In this research, we have selected the region of Jawoon river that is the area of high land vegetable growing in the upper Soyang Reservoir and we have observed actual floating materials that generate negative nutrition and turbidity of the Reservoir water and the changes of water quality by raining of each month for one year of 2005 in order to monitor the relationship of pollution sources by the outflow of rain water. In addition, we also have conducted statistical inspection methods such as correlation analysis and regression analysis on strength of raining force and rain continuance time among the elements affecting the outflow of floating materials.

• 산업기술연구
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• 제27권B호
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• pp.221-227
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• 2007

This research investigates the turbidity and flow of river for an year, 2005, in order to examine the relation of the generation of turbidity according to the outflow of min water. For this research, the region of Jawoon river where is the area of high land vegetable growing in the upper Soyang Reservoir is selected to observe actual floating materials that generate negative nutrition and turbidity of the Reservoir water and the changes of water quality by raining of each month. In addition, the researcher has conducted statistical inspection methods, such as correlation analysis and regression analysis on strength of raining force, and rain continuance time among the elements affecting the outflow of floating materials.