• 한국물환경학회지
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• 제24권1호
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• pp.99-106
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• 2008

With globally increasing interests in climate-soil-vegetation system, a new stochastic model of soil water and plant water stress is derived for better understanding of the soil water and plant water stress dynamics and their role in water-controlled ecosystem. The steady-state assumption is used for simplifying the equations. The derived model is simple yet realistic that it can account for the essential features of the system. The model represents the general characteristics of rainfall, soil, and vegetation; i.e. the soil moisture constitutes the decrease form of the steady-state and the plant water stress becomes increasing with the steady state when the rainfall is decreased. With this model, further deep study for the effects of soil water and plant water stress on the system will be accomplished.

• 상하수도학회지
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• 제23권2호
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• pp.251-255
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• 2009

Foreign and domestic seawater desalination plant market investigation was performed to analyze the worldwide trend of seawater desalination plant market and to establish the activation plan for seawater desalination plant application. Water demand and seawater desalination related laws and regulations were investigated and analyzed for the activation plan. RO type and large scale plants are popular nowadays however there are only small plants in island region in Korea. There will be about $1 million\;m^3/day$ deficit in 2015 according to the water demand forecasting from Ministry of Environment and Ministry of Land, Transportation, and Maritime Affairs in Korea. Therefore, it is necessary to activate the domestic application of seawater desalination plant to secure stable water resources. To activate the domestic application of seawater desalination plant, first, we need to establish regulations, support system in the water service law for seawater desalination plant. Second, related Ministry should increase the support for the operation and management of seawater desalination plant and suggest the construction of seawater desalination plant for water resources security near seaside region.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.327-332
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• 2000

This study was carried out to investigate the water requirement of green peppers which are cultivated in a greenhouse under the different soil water conditions. The meteorological conditions during the experiment period was not predominantly different from the conditions in a normal year. The highest leaf area per plant, plant height, and yield were 6,143$\textrm{cm}^2$/plant, 107cm, and 751g/plant, respectively. And daily variation of water requirements of green peppers ranged from 30 to 1,250g/d/plant which was fluctuated with significant difference. Total water requirements per plant which cultivated under the soil water conditions with different saturation ratios were 23,619g for P100, 43,044 for P80, and 2915g for P60, respectively. There were close correlation between plant height and water requirements. Low correlations were found between greenhouse ambient temperature and water requirement, while significant linear regression was shown between both of humidity and solar radiation and water requirement.

• 한국물환경학회지
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• 제28권1호
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• pp.71-77
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• 2012

The performance and characteristics of nutrient removal in wetlands influenced by plant type. We tested a floating plant, Eichhornia crassipes, and a submerged plant, Ceratophyllum demersum, under the same environmental conditions to understand the differences in nutrient uptake by these different plant forms. The total nitrogen and phosphorus in the water decreased in the following order: Water Only < Water + Soil < Floating Plants ${\approx}$ Submerged Plants and Water Only < Water+Soil < Floating Plants < Submerged Plants. Nitrogen and phosphorous concentrations increased in both plants; however, the phosphorous concentration was greater in C. demersum than E. crassipes. The submerged plant exhibited higher phosphorus uptake per unit biomass than the floating plant, but nitrogen uptake did not differ significantly. These results suggest that the presence of soil influences nitrogen and phosphorus removal from water, and that wetland plants play an important role in the assimilation and precipitation of phosphorus. Understanding the differences in contaminant removal performance and characteristics of various plant forms can help in the selection of diverse plants for constructed wetlands to improve water quality and provide ecosystem services such as wildlife habitat and landscape enhancement.

• 한국물환경학회지
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• 제25권4호
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• pp.507-514
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• 2009

In this study, a dynamic modeling scheme is presented to describe the probabilistic structure of soil water and plant water stress index under stochastic precipitation conditions. The proposed model has the form of the Fokker-Planck equation, and its applicability as a model for the probabilistic evolution of the soil water and plant water stress index is investigated under a climate change scenario. The simulation results of soil water confirm that the proposed soil water model can properly reproduce the observations and show that the soil water behaves with consistent cycle based on the precipitation pattern. The simulation results of plant water stress index show two different PDF patterns according to the precipitation. The simple impact assessment of climate change to soil water and plant water stress is discussed with Korean Meteorological Administration regional climate model.

• 한국물환경학회지
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• 제22권3호
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• pp.437-443
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• 2006

The Water usage is relationship which is close with the administrative cost from industrial facility. It is not easy to reduce a water usage. This research is the optimization of the waste water quantity which process waste water integration of the standard thermal power plant in system operate time. The turbine rotates by force of the steam and it produces an electricity. Demineralization Water is manufacture purity manufacturing equipment and it is supplied in power plant channel. We knew a possibility of reducing from pure control process. When it is reduced the Back Washing time, Rinsing time of the gravity filter and the activated carbon filter. Also, It is possible even from regeneration phase in Condensate Polishing Demineralization System. In addition, There is also the water which the drain of the sampling water for watching the condition of power plant process will be able to use. Integrates these processes it will be able to reduce an annual 30,000 ton degree. The research is want to use the fundamental data for the water curtailment of the power plant.

• 신재생에너지
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• 제5권3호
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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.

• 한국환경농학회지
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• 제30권3호
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• pp.304-309
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• 2011

본 연구는 비점오염원 처리를 위한 자유수면형 인공습지인 복내 바이오파크 인공습지에서 수생식물에 의한 영양염류의 흡수특성을 평가하고자 하였다. 복내 바이오파크 인공습지내 주요 우점종은 달뿌리풀, 수련, 부들, 갈대 및 줄이었으며 최대건물생산량을 보인 8월의 주요 우점식생의 한 주당 건물생산량은 부들(54.27 g/plant) > 달뿌리풀(44.30 g/plant) ${\geqq}$ 갈대(39.60 g/plant) ${\geqq}$ 줄(37.80 g/plant) ${\fallingdotseq}$ 수련(36.75 g/plant) 순으로 높았다. 복내 바이오파크 인공습지내 수생식물의 질소 함량은 지상부의 경우 달뿌리풀, 수련, 부들, 갈대 및 줄이 각각 1.80~2.06%, 1.94~2.14%, 2.07~2.57%, 2.20~2.33% 및 2.20~2.33% 범위로 부들이 다른 수생식물에 비해 약간 높았으나 시기별로 큰 차이 없었으며 지하부의 질소 함�c도 이와 유사한 경향이었다. 복내 바이오파크 인공습지내수생식물의 인 함량은 지상부에서는 달뿌리풀(9400~9900 mg/kg 범위) 및 지하부에서는 줄(4964~6452 mg/kg 범위)이 다른 수생식물에 비해 약간 높았으나 시기에 따른 수생식물의 인 함량은 큰 차이 없이 비슷하였다. 복내 바이오파크 인공습지내 수생식물의 최대 질소 흡수량은 8월에 달뿌리 풀이 773 mg/plant, 수련이 625 mg/plant, 부들이 1206 mg/plant, 갈대가 754 mg/plant 및 줄이 768 mg/plant 이었다. 수생식물의 최대 인 흡수량은 8월에 달뿌리풀이 397 mg/plant, 수련이 177 mg/plant, 부들이 411 mg/plant, 갈대가 261 mg/plant 및 줄이 229 mg/plant이었다. 복내 바이오파크 인공습지내 수생식물 중 부들의 영양염류 흡수량이 가장 많았다. 이상의 결과는 향후 비점오염원 처리를 위한 인공습지 시공시 습지특성에 맞는 최적의 수생식물을 선정하는데 활용될 수 있을 것이다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.52-56
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• 2009

In this study a dynamic modeling scheme is presented to derive the probabilistic structure of soil water and plant water stress when subject to stochastic precipitation conditions. The newly developed model has the form of the Fokker-Planck equation, and its applicability as a model for the probabilistic evolution of the soil water and plant water stress is investigated under climate change scenarios. This model is based on the cumulant expansion theory, and has the advantage of providing the probabilistic solution in the form of probability distribution function (PDF), from which one can obtain the ensemble average behavior of the dynamics. The simulation result of soil water confirms that the proposed soil water model can properly reproduce the results obtained from observations, and it also proves that the soil water behaves with consistent cycle based on the precipitation pattern. The plant water stress simulation, also, shows two different PDF patterns according to the precipitation. Moreover, with all the simulation results with climate change scenarios, it can be concluded that the future soil water and plant water stress dynamics will differently behave with different climate change scenarios.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.165.2-165.2
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• 2011

Flow with suction to water turbine must be in stable state at small hydraulic power plant. But because of water level fluctuation and water gate effect according to irregular supply of cooling water, it would happen to produce bubble and vortex and finally lead to problems in power-plant system. With utilizing the concept design of double size gate, surface water overflowed the overhead of gate for stable flow at suction. We developed the overflow condition and analyzed the design factor with existed one such as water level(overflow amount) and overhead of water gate(overflow figure). Flow test and CFD simulation say that flow have stable state around suction and 20% of wave reduction effect at surface layer after surface water overflow.