• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.783-784
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• 2010

• 수도
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• 통권62호
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• pp.39-53
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• 1993

• 대한기계학회논문집B
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• 제34권8호
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• pp.791-797
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• 2010

수도미터를 통한 유량측정 및 분석결과의 신뢰성은 측정정확도에 따라 좌우된다. 수도미터의 불감률은 수도사업자에게 재정손실이나 유수율 감소와 같은 많은 문제점을 야기시킨다. 본 연구의 목적은 실험적인 방법을 통하여 효율적인 운영관리 기술과 차별화된 서비스를 제공하기 위한 최적의 메커니즘 채택과 같은 핵심기술 개발과 지원을 하고자 함이다. 본 연구에서는 중고 수도미터를 이용하여 구경, 제작사, 사용연수 및 사용량별로 실험적으로 수행하였다. 연구결과 사용연수가 길어질수록 최소유량에 서의 오차가 "-" 방향으로 커지는 것을 확인하였다.

• 한국환경보건학회지
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• 제25권3호
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• pp.13-22
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• 1999

For the purpose of inquiring into the actual conditions of water quality management of Simple Piped Water Supply(SPWS) and the satisfaction and attitudes of inhabitants about utilizing water-supply, this research was done through the questionnaires, the investigation of surrounding environment and water quality analysis in the Sangju city, Kyungsang-pookdo during 4 months from March to June, 1998. The fountainhead of SPES using ground water accounted for 65.3%, which was the highest rate in the group. Most of them was at least 10 years in the number of utilization year. 79.6% of them were exposed to many sorts of surrounding pollution origins. The examination of water was performed only through a test about water purification and 24.5% of them disinfection by chlorine also no residual chlorine was detected at all. All the waterworks did not have any education to the managers of water quality and 81.5% of them held physical examination. As a result of the water examination about SPWS, 65.3% of them were found incongruity and the valley and springing water accounted for higher than the underground water in the rate of incongruity. Looking into the details of the result in the water examination, a category of colon bacilli was ranked in the highest rate and the next one was general bacilli, nitric acid nitrogen and turbidity in order. In the satisfaction degree of the water quality, the satisfied accounted for 44.6%, and 29.2% each. Over the state of satisfaction about the ways of water examination, satisfaction accounted for 44.6%, and unsatisfaction 28.3%. Summarizing the result of the above-stated, the state of Water Quality Management of the SPWS was in a poor condition. Thus for the water Quality Management, systematic and scientific water Quality Management mainly by the administrative organization other than voluntary management by the village should be done beyond doubt. Additionally the opinions and demands of inhabitants utilizing the water supply have to be positively reflected in the affairs of water Quality Management so that the distrust of inhabitants to the SPWS should be settled.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.115-118
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• 2005

상수도관망에서 발생하는 누수현상은 수자원의 손실뿐만 아니라 압력손실로 인한 추가적 가압 설비의 필요성 및 누수되는 관로 주변의 토질의 약화 등을 초래하여 관망의 유지관리를 어렵게 하고, 심각한 경제적 손실을 야기하고 있다. 이에 구역고립으로 인한 수압과 유량 등을 상시 모니터링하여 누수사고의 적극적인 대처와 누수발생을 미연에 방지함으로써 유수율을 향상 시킬 수 있다 .실제 구역고립 후 계속되는 수압 조절 및 유입유량의 모니터링으로 인하여 구역내 유수율 산정결과 평균 유수율은 88.94%로서 부산광역시 2003년도의 유수율 79.5%보다 9.44% 높게 조사되었다.

• 한국콘텐츠학회논문지
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• 제6권11호
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• pp.310-316
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• 2006

상수도관망에서 발생하는 누수현상은 수자원의 손실뿐만 아니라 압력손실로 인한 추가적 가압 설비의 필요성 및 누수 되는 관로 주변의 토질의 약화 등을 초래하여 관망의 유지관리를 어렵게 하고, 심각한 경제적 손실을 야기하고 있다. 본 연구는 구역고립으로 인한 수압과 유량 등을 상시 모니터링 하여 누수사고의 적극적인 대처와 누수발생을 미연에 방지함으로써 유수율을 향상시킬 수 있다. 실제 구역고립 후 계속되는 수압조절 및 유입유량의 모니터링에 인하여 구역 내 유수율 산정결과 평균 유수율은 88.94%로서 부산광역시 2003년도의 유수율 79.5%보다 9.44% 높게 조사되었다.

• 생물환경조절학회지
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• 제25권4호
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• pp.270-276
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• 2016

This study analysed overall heat transfer coefficient, heat transmission, and rate of indoor air heating provided by water curtain in order to determine the heat transfer characteristic of double-layered greenhouse equipped with a water curtain system. The air temperatures between the inner and outer layers were determined by the water flow rate and inlet water temperature. Higher water flow rate and inlet water temperature resulted in the increased overall heat transfer coefficient between indoor greenhouse air and water curtain. However, it was found that with higher levels of water flow rate and inlet water temperature, indoor overall heat transfer coefficient was converged about $10W{\cdot}m^{-2}{\cdot}^oC^{-1}$. The low correlation of overall heat transfer coefficient between water curtain and air within double layers was likely because the combination of greenhouse shape, wind speed and outdoor air temperature as well as water curtain affected the heat transfer characteristics. As water flow rate and inlet water temperature increased, the heat transferred into the greenhouse by water curtain also tend to rise. However it was demonstrated that the rate of heat transmission from water curtain into greenhouse with water curtain system using underground water was accounted for 22% to 28% for total heat lost by water curtain. The results of this study which quantify heat transfer coefficient and net heat transfer from water curtain may be a good reference for economical design of water curtain system.

• 미생물학회지
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• 제29권5호
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.

• 한국농공학회논문집
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• 제50권2호
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• pp.11-16
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• 2008

The effects of water and pesticide management practices on ponded water pesticide concentrations in a paddy plot were analysed using the RICEWQ model. The molinate which is a herbicide widely used in rice culture, and frequently detected in paddy environment was selected. In a previous study, the RICEWQ model was successfully calibrated with field data obtained from a paddy plot in Daegu. The calibrated model was run using water and pesticide management scenarios with a set of measured meteorological data for 1997-2006 in Daegu. For all three ponded water depths with the label rate application, the amount of molinate dissipated in ponded water and volatilized accounted for more than 70%, and the runoff losses were less than 9%. The molinate losses through drainage in the very shallow ponded depth showed 40% less than that in deep ponded depth. Comparing with the deep and shallow ponded depth, the very shallow depth was the best with regards to the reduction of molinate runoff losses. Simulations with different pesticide application rates, label rate and double label rate, showed molinate concentrations in the ponded water increased linearly with the application rate increase.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.414-418
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• 2008

The effects of paper properties such as density, air permeability, water vapor transmission rate on the thermal performance of plate-type enthalpy exchanger were experimentally investigated. Three enthalpy exchanger samples having different properties were made, and were tested according to the standard test procedure (KS B 6879). Effective efficiencies were defined, which accounted for the air leakage between supply and exhaust streams. Results showed that paper density affected the sensible heat transfer of the samples. Sensible heat transfer increased with density of the paper. It was also shown that water vapor transmission rate alone was not a proper indicator for the efficiency of latent heat transfer. Air permeability should also be considered for adequate evaluation of the latent heat transfer. Best performance was obtained for the sample having highest paper density and moderate water vapor transmission ratio.