• 상하수도학회지
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• 제11권2호
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• pp.94-104
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• 1997

Ozone Treatment is getting a common process in a water treatment plant all over the nation. Especially an advanced water treatment using ozone and biofiltration has been a typical method in the regions where using the Nak-Dong River as a drinking water source. The effectiveness of ozone treatment in a continuous flow contact system was investigated with sand filtered water of the Nak-dong River. Pilot tests of the experiments were performed three times of the year like June, August, and October 1995. Most degradable organics of sand filtered water were oxidized in the first and second contact chamber of the system. Ozone treatment was effective for the removal of UV254 absorbance. However, Noticeable removals of $KMnO_4$ demand and TOC(Total Organic Carbon) were occurred when their concentrations exceeded about 5mg/l. The organics causing $KMnO_4$ demand and TOC were degraded into lower molecular matter in an early stage of the ozone contact in the system. Dissolved oxygen concentration was increased after ozone treatment.

• 한국수자원학회논문집
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• 제52권7호
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• pp.463-473
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• 2019

본 연구에서는 공급 우선순위에 따른 물수급 분석 결과의 비교를 위해 국내 수자원장기종합계획에서 활용한 K-WEAP (Korea-Water Evaluation And Planing System) 모형과 MODSIM (Modified SIMYLD) 모형을 이용하여 분석하였다. 기존의 수자원장기종합계획은 수요처의 공급 우선순위를 모두 동일하게 공급하는 것으로 가정하여 분석하였으며 K-WEAP은 최대충족률을 만족시키기 위한 비율 배분을 수행하는 반면 MODSIM은 물 공급 우선순위의 적용이 필수적인 것으로 분석되었다. 먼저 우선순위에 따른 한강 유역의 물수급 분석 결과, 평균 1,035 천 $m^3$의 물부족이 감소하였으며 이는 생 공용수의 배분량이 증가하면서 회귀수량이 증가하고, 수자원의 재이용이 많아지기 때문인 것으로 분석되었다. 우선순위를 적용한 K-WEAP과 MODSIM의 분석결과를 비교할 경우, 상대오차 최대 5.3%이내, 결정계수($R^2$)는 0.9999로 매우 유사한 물 부족이 발생하였다. 또한 두 모형 모두 합리적인 물 부족 분석 결과를 제공한다면, 모형의 구축과 데이터 처리에 해당하는 GUI 편의성은 K-WEAP이 더 우수한 것으로 나타났으나, 구동시간의 효율성은 MODSIM이 더 우수한 것으로 분석되었다. 향후 K-WEAP모형 뿐만 아니라 MODSIM 모형을 활용한 다양한 시나리오에 따른 분석을 수행할 수 있을 것으로 기대된다.

• 한국태양에너지학회 논문집
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• 제29권5호
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• pp.1-7
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• 2009

Energy demands for offices in Korea are surveyed and analyzed to generate communicational models for simulations. Daily energy loads of 13 office buildings scattered in the 6 largest cities in the country are surveyed and analyzed based on energy consumption log sheets. Detailed hourly loads that are frequently required when a detailed operation simulation is performed are measured using remote data acquisition processes for 3 offices. The complete load demand models of electricity, cooling, heating and hot water are established by combining the daily and hourly patterns based on the statistical behavior of the hourly patterns.

• 조명전기설비학회논문지
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• 제15권1호
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• pp.78-83
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• 2001

본 연구에서는 아파트에 시설되어 있는 동력설비들의 운전실태를 측정하고 분석하여 동력변압기 최적용량산출을 위한 동력부하의 종합수용률을 제시하였다. 측정결과 설비별 수용률은 급수동력부하는 47[%]로 분석되었으며 변압기를 효율적으로 운전하기 위해서는 동력부하의 종합 수용률을 현재의 52[%]에서 42[%]로 변경하는것이 적절한 것으로 분석되었다.

• 한국농공학회논문집
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• 제66권3호
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• pp.39-51
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• 2024

To effectively implement the integrated water management policy outlined in the National Water Management Act, it is essential to analyze agricultural water supply and demand at both basin and water district levels. Currently, agricultural water is primarily distributed through open canal systems and controlled by floodgates, yet the utilization-to-supply ratio remains at a mere 48%. In the case of agricultural water, when analyzing water balance through existing national basin water resource models (K-WEAP, K-MODISM), distortion of supply and regression occurs due to calculation of regression rate based on the concept of net water consumption. In addition, by simplifying the complex and diverse agricultural water supply system within the basin into a single virtual reservoir, it is difficult to analyze the surplus or shortage of agricultural water for each field within the basin. There are limitations in reflecting the characteristics and actual sites of rural water areas, such as inconsistencies with river and reservoir supply priority sites. This study focuses on the development of a model aimed at improving the deficiencies of current water balance analysis methods. The developed model aims to provide standardized water balance analysis nationwide, with initial application to the Anseo standard watershed. Utilizing data from 32 facilities within the standard watershed, the study conducted water balance analysis through watershed linkage, highlighting differences and improvements compared to existing methods.

• 한국의류학회지
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• 제17권2호
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• pp.329-338
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• 1993

The purpose of this study was to design an instrument to simulate the Human-Clothing-Environment system and evaluate the water vapour transport properties of sweat absorbent PET fabrics. The instrument was composed of sweat generating part, clothing part which can simulate clothing layers, and enviromental part. As specimens, sweat absorbent PET, regular PET, cotton, nylon and acrylics fabrics were included. For the water vapour transport(WVT), relative humidities and temperatures were measured by film type humidity sensors and thermocouples, respectively. Water vapour pressures were calculated with measured RH's and temperatures. For the liquid water transport, wickability and demand wettability were measured. Results showed that there was a difference in terms of water vapour transport mechanism depending on the fiber type ; sweat absorbent PET showed higher WVT at the transient period then equilibrated, whereas other fabrics showed lower WVT at the transient period then increased continuously. These differences are expected to affect to the difference in the comfort properties of clothings. Sweat absorbent PET showed higher demand wettability and wickability than other fabrics. Wide application of the instrument was also suggested.

• 상하수도학회지
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• 제20권1호
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• pp.94-103
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• 2006

The pollution in closing water can be caused by not only artificial factor like sewage but also natural factor like elution from sediment. In this study we analyzed Sediment Oxygen Demand (SOD) for verification of sediment purification effect and sediment elution experiment as well as general items like COD, TN, TP, SS to complement and assess the effect of sediment and water quality. The experiment result showed that the release rate of OSD system were 4 times and 3 times as large as control for P and Fe respectively. SOD for operated OSD system and control were $12.18gO_2{\cdot}m^{-2}{\cdot}d^{-1}$ and $47.95gO_2{\cdot}m^{-2}{\cdot}d^{-1}$. From water qualities analyzed by COD, TN, TP, SS, chlorophyll-a, the removal efficiency increase of TN, TP, chlorophyll-a and COD were about 10~20%, 40~50% and 10% respectively. In conclusion, OSD can contribute to improvement of both the waterbody and the sediment environment effectively.

• Environmental Engineering Research
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• 제23권1호
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• pp.99-106
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• 2018

Lack of information on the Biochemical Oxygen Demand (BOD) decay rates of river water under the tropical environment has triggered this study with an aim to fill the gap. Raw sewage, treated sewage, river water and tap water were mixed in different proportions to represent river water receiving varying amounts and types of wastewater and fed in a laboratory flume in batch mode. Water samples were recirculated in the flume for 30 h and BOD and Carbonaceous BOD (CBOD) concentrations were measured at least six times. Decay rates were obtained by fitting the measured data in the first order kinetic equation. After conducting 12 experiments, the range of BOD and CBOD decay rates were found to be 0.191 to 0.92 per day and 0.107 to 0.875 per day, respectively. Median decay rates were 0.344 and 0.258 per day for BOD and CBOD, respectively, which are slightly higher than the reported values in literatures. A relationship between CBOD decay rate and BOD decay rate is proposed as $k_{CBOD}=0.8642_{k_{BOD}}-0.0349$ where, $k_{CBOD}$ is CBOD decay rate and $k_{BOD}$ is BOD decay rate. The equation can be useful to extrapolate either of the decay rates when any of the rates is unknown.

• Environmental Engineering Research
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• 제14권4호
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• pp.256-260
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• 2009

This study used the extensive monitoring datasets of the Korea Ministry of Environment to examine trends in dissolved organic carbon (DOC) in Han River raw water. To estimate the organic contents of water, we adopted allied parameters such as biochemical oxygen demand (BOD) and chemical oxygen demand (COD) as substitutes for DOC. Spatial and temporal analyses were performed on monthly BOD and COD data from 36 monitoring stations (14 for Main Han River, 7 for North Han River and 15 for South Han River) measured from 1989 to 2007. The results of trend analysis indicated that, on the whole, water quality according to BOD showed a downward trend at more than 67% of monitoring stations (9 for Main Han River, 6 for North Han River and 9 for South Han River). However, the water quality of COD showed an upward trend at more than 78% of monitoring stations (8 for Main Han River, 7 for North Han River and 13 for South Han River). The upward trend of COD contrary to the BOD trend indicates that there has been an increase in recalcitrant organic matter in Han River water that is not detectable by means of BOD.

• 한국환경과학회지
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• 제21권9호
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• pp.1115-1129
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• 2012

The objective of this study was to analyze long-term annual and seasonal trends of water chemistry on landuse patterns and seasonal precipitation using 72 sampling sites within Namhan River watershed during 2001-2010. Water quality, based on multi-parameters of water temperature(WT), dissolved oxygen(DO), biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(TN), total phosphorus(TP), and electric conductivity(EC) varied largely depending on monsoon rain and landuse patterns such as forest, cropland, and residence. Concentrations of BOD and COD as an indicator for organic matter pollution, increased during summer monsoon season at the cropland and residential streams. Values of TN and TP were higher in residential streams than in the forest and cropland streams. In the meantime, DO values had weak relations to the landuse patterns of forest and cropland cover. Water quality was worst in cropland and residential streams, and also most degradated in 4th order streams. Overall, our results suggest that efficient water quality management is required in the cropland and residential landuse streams.