• 상하수도학회지
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• 제30권6호
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• pp.653-662
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• 2016

Recently, advanced metering infrastructure (AMI) has been recognized as a core technology of smart water grid, and the relevant market is growing constantly. In this study, we developed all-in-one smart water meter of the AMI system, which was installed on the test-bed to verify both effectiveness and field applicability in office building water usage. Developed 15 mm-diameter smart water meter is a magneto-resistive digital meter, and measures flow rate and water quality parameters (temperature, conductivity) simultaneously. As a result of the water usage analysis by installing six smart water meters on various purposes in office building water usage, the water usage in shower room showed the highest values as the 1,870 L/day and 26.6 liter per capita day (LPCD). But, the water usage in laboratory was irregular, depending on the many variables. From the analysis of the water usage based on day of the week, the water usage on Monday showed the highest value, and tended to decrease toward the weekend. According to the PCA results and multivariate statistical approaches, the shower room (Group 3) and 2 floor man's restroom sink (Group 1-3) have been classified as a separate group, and the others did not show a significant difference in both water use and water quality aspects. From the analysis of water usage measured in this study, the leak or water quality accident did not occur. Consequently, all-in-one smart water meter developed in this study can measure flow rate and water quality parameters (temperature, conductivity) simultaneously with effective field applicability in office building water usage.

• 상하수도학회지
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• 제31권5호
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• pp.447-457
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• 2017

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

• 한국수자원학회논문집
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• 제57권1호
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• pp.1-8
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• 2024

우리나라는 기후변화의 영향으로 지속되는 가뭄으로 인해 물 부족 문제가 심화되고 있다. 제1차 국가물관리기본계획에 따르면, 생활 및 공업용수 부족량은 과거 최대 가뭄빈도(50년) 기준으로 0.07억 m³/년으로 전망되고 있다. 이러한 물 부족 문제에 효과적으로 대응하기 위해서는 장기적인 용수 수요 전망이 필수적이다. 공업용수의 경우 월별 사용량이 비교적 일정하지만, 생활용수의 경우 월별 패턴이 뚜렷하기 때문에 연단위 분석이 아닌 월단위 분석을 수행해야 한다. 본 연구는 충청권역을 대상으로 2017~2021년의 월별 용수 이용량 자료에 대해 패턴을 분석하고, 기후 변수와의 상관성을 이용하여 용수 분배 비율을 계산하였다. 그 결과 월별 생활용수 이용량을 연 이용량으로 나눈 월별 용수 이용률을 다시 평균기온으로 나누는 분법으로 계산한 경우가 절대오차가 가장 작게 산정되었으며, 이를 활용하여 충청권역의 월별 분배 비율을 산정하였다. 또한 충청권역의 월별 분배 비율에 SSP5-8.5 시나리오의 평균기온을 곱해 충청권역의 미래 월별 용수 이용률을 전망하였다. 그 결과, 최댓값의 평균은 1.16에서 1.29로 증가하고 최솟값의 평균은 0.86에서 0.84로 감소하였으며, 1사분위수는 0.95에서 0.93으로 감소하고 3사분위수는 1.04에서 1.06으로 증가하였다. 따라서 미래에는 현재와 비슷한 패턴을 유지할 것으로 보이지만, 월별 용수 이용률의 변동성은 커질 것으로 예상된다.

• 상하수도학회지
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• 제31권2호
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• pp.177-186
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• 2017

This study concerned the analysis on the efficiency of the conversion of water tank type supply system to direct water supply system to examine the feasibility of the conversion, as well as the calculation of optimal conversion range that enables the supply of safe, high-quality water at stable pressure in accordance with the standards of water supply facility. The results of this research showed that when converting water supply system from water tank type supply system to direct water supply system, more nodal points could be properly converted and more reduction of electricity usage was expected in case water pressure rather than residence time was fixed. This means that higher efficacy can be obtained by fixing water pressure when converting water supply system. However, since the number of the locations that received on-spot inspection was small and the electricity usage measured was not exclusively by water supply facility, it is difficult to judge that such reduction of electricity usage accurately represents reduced electricity usage by water supply facility alone. therefore, after having secured on-spot information about a larger number of locations in apartment complexes that have converted water supply system, and utilizing information about electricity usage exclusively by water supply facility, the proposed method of this research could be applied to accurately deducing expected reduction of electricity usage by water supply facilities of various other apartment complexes. It is also considered possible to deduce an effective operation method of water supply system by finding out an area that shows low pressure or low residual chlorine concentration in the optimal conversion range of water supply, followed by estimating the proper location of pumping station or the proper chlorine dosage at the power purification plant that supply water to the target area.

• 한국환경과학회지
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• 제24권4호
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• pp.515-524
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• 2015

The estimation of groundwater usage in Jeju island is important to understand hydrologic cycle system and to plan management of water resource because large amounts of groundwater have been used for agricultural and domestic purpose. The model has been developed to estimate agricultural groundwater usage for garlic at uplands and citrus at orchards raising outdoors using the soil water balance model from FAO 56, respectively. The total amount of water supplied for the crop evapotranspiration and the multipurpose function such as sprout promotion can be simulated by the model. However, due to the discrepancy of water use in initial stage between calculated and observed, the model was calibrated and verified using actual groundwater usage monitoring data for 3.5 years (2011.6 to 2014.12) at three uplands for garlic and three orchards for citrus. Consequently, it would be concluded that the model simulated efficiently actual water usage in that root mean square (RMS) and normalized RMS of the validation stage were less than 8.99 mm and 2.43%, respectively, in two different conditions.

• 한국환경과학회지
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• 제20권10호
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• pp.1297-1308
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• 2011

This study is to analyze the characteristics of golf course water usage using groundwater and rainwater data obtained from 17 golf courses in Jeju Island during 2007~2009. The groundwater usages were 246,275 $m^3/year$, 213,062 $m^3/year$, 155,235 $m^3/year$, and 126,666 $m^3/year$ in the west, south, east, and north regions, respectively. Monthly rate of the amount of groundwater usage to the amount of permission was 29.5%. The rainfall usages were 386,591 $m^3/year$, 326,464 $m^3/year$, 251,248 $m^3/year$, and 232,061 $m^3/year$ in the south, west, east, and north regions, respectively. Monthly rate of rainwater usage to the amount of water retention of golf courses was 19.6%. The average annual water usage in the 17 golf courses was 499,377 $m^3/year$. From the average usage, it was found that the rainwater usage (305,126 $m^3/year$ ) was 1.6 times higher than that of groundwater (194,251 $m^3/year$ ). That means the annual average rainwater usage to the entire water usage was 61.1%, which was above the criteria of 40%.

• 한국수자원학회논문집
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• 제54권spc1호
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• pp.1083-1093
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• 2021

물 사용량 예측은 최적의 용수 공급 운영 방안을 수립하고 전력 소비량 절감을 위하여 꼭 필요한 과정이라고 할 수 있다. 그러나 수용가 단위의 물 사용량은 용도, 사용자의 패턴, 날씨 등의 다양한 요인으로 인해 변화하는 비선형적 특성을 지니고 있다. 따라서 본 연구에서는 비선형적인 수용가 단위의 물 사용량을 예측하기 위하여 다양한 기법들을 연계한 KWD 프레임워크를 제안하고자 하였다. 즉, 먼저 개별 수용가 마다 용도에 따른 유사한 패턴을 파악하기 위해 K-means (K) 군집분석을 수행하였고, 잡음성분을 제거함으로써 핵심적인 주기패턴을 파악하기 위해 Wavelet (W) 방법을 적용하였다. 또한 비선형적 특성을 학습시키기 위해 Deep learning (D) 알고리즘을 적용하였다. 그리고 기존의 선형 시계열 모형인 ARMA 모형과 비교하여 KWD 프레임워크의 성능을 분석하였다. 그 결과 제안된 모형의 상관성은 92%, ARMA 모형은 약 39%로 KWD 프레임워크가 2배 이상의 성능을 가지는 것으로 분석되었다. 따라서 본 연구에서 제안한 방법을 활용할 경우 정확한 물 사용량 예측이 가능해질 것이며, 상황에 따른 최적의 공급 방안을 수립할 수 있을 것이다.

• 상하수도학회지
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• 제28권5호
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• pp.509-516
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• 2014

This study describes a reasonable planning method for water meter replacement which can minimize the metering under-registration for an increasement of revenue water. The increment analysis of real water usage was used to establish a replacement plan. The meter replacement database collected from K City was used as the basis of this analysis. The database included 964 connections of domestic and non-domestic consumers that had their meter replaced by aging at 2011. The result showed that the corelation between unregistered water volume and water meter age was lower than commonly expected where the current criteria of replacement is only water meter age(8 years) excluding the meters older than 13 years. And in the analysis result of water usage for 8 years, the total amount and increment of water usage had a significant effect on unregistered water volume. However the relation was different tendency as a total volume and slope of increment. In case of total water volume was larger than 10,000, larger than 7,000 and increment of 0.0 ~ -0.3, larger than 6,000 and increment more than -0.3 were analysed to need a replacement because of metering under-registration.

• 한국환경교육학회지:환경교육
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• 제17권2호
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• pp.60-78
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• 2004

A survey performed on property of water usage, a recognition and stand on water, and awareness of practice related to water saving among primary and secondary teachers in Daegu metropolitan city leads to the following result. First, regarding the actual condition of water usage, boiled tap water was most preferred, followed by purified tap water, mineral water, and water from a mineral spring respectively. Second, the result of a survey regarding a recognition and stand on water presents that the quality of purified water and mineral water is generally trusted, not including tap water. A majority of teachers barely had any ideas on the process of tap water supplies and sewage disposal system. Third, another survey was performed to determine whether there's a gender difference on a general recognition of and stand on water usage, actual practice of water saving and love for water. As a result, 7 out of 25 questions showed the difference of significance by p<.05. As for tap water service and sewage disposal system, there were differences on 5 out of 6 questions, indicating that male teachers are more knowledgable than their female counterparts. Fourth, the result of the research about the recognition and attitudes about water and water saving of the teachers who were categorized by the age group showed that 14 questions of the 25 questions had differences in p<.05 level. Teachers in their twenties and thirties had less interest than those in their forties and fifties.

• 설비공학논문집
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• 제23권10호
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• pp.656-661
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• 2011

The amount of water resources that can be used tend to be decreased gradually. In contrast, the rapidly increasing water consumption is a problem that need to be addressed. Renovation and equipment replacement to improve energy efficiency and to reduce expenditure for building usage is required. But the excessive initial investment cost and the prolonged of pay back period may be uneconomical choice. Water usage for cleaning the toilet bowl accounts for 27%of the total water usage. Water-saving valve that can select the amount of water for cleaning toilet bowl can be reduced expenditure. After installing water-saving valve, analysed the economic effects. Water-saving valves compared with flush valves, and researched the amount of water usage. Then analyzed for the economic effects. Water-saving valve was used 5.6 ${\ell}$/time for cleaning toilet bowl. In contrast, flush valve was consumed 8.4 ${\ell}$/time. Water-saving valve's water-saving rate was 33.3%. The initial payback period for Water-saving valve was 459.5 days. By a small investment in water saving valve, the economic benefits can be obtained.