• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.869-877
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• 2008

The purpose of this study is to investigate the trends and patterns of variou kind of water uses in a household by metering in Korea. Water use components are classified by toilet, washbowl, bathing, laundry, kitchen, etc. Flow meters are installed in 146 household selected by sampling in all around Korea. The data are gathered by web-based data collection system from the year 2002 to 2006, considering pre-investigated data such as occupation, revenue, family members, housing types, age, floor area, water saving devices, education, etc. Reliable data are selected by upper fence method for each observed water use component and statistical characteristics are estimated for each residential type to determine liter per capita per day. Estimated domestic per capita day show an indoor water use with the range from $150{\ell}pcd$ to $169{\ell}pcd$ for each housing type as the order of high rise apartment, multi-house, and single house. As the order of consuming amount among water use components, it is investigated that toilet($38.5{\ell}pcd$) is the first, and the second is laundry water($30.8{\ell}pcd$), the third is kitchen($28.4{\ell}pcd$), the fourth is bathtub($24.7{\ell}pcd$), the next is washbowl($15.4{\ell}pcd$). The results are compared with water uses in U.K. and U.S. As life style has been changed into western style, pattern of water use in Korea is tend to be similar with the U.S. water use pattern. Compared with the surveying results by Bradley, on 1985. Thirty liter of total use increased with the advancement of economic level, and a little change of water use pattern can be found. Especially, toilet water take almost half part of total water use and laundry water shows lowest as 11% in surveying at the year of 1985. But, this study shows that 39 liter, 28% of toilet water, has been decreased by the spread of saving devices and campaign. It is supposed that the spread large sized laundry machine make by-hand laundry has been decreased and water use increased. Unit water amount of each end-use in household can be applied to design factor for water and wastewater facilities, and it play a role as information in establishing water demand forecasting and conservation policy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.595-601
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• 2008

The purpose of this study is to investigate the trends and patterns of various kind of water uses in a household by metering in Korea. Water use components are classified by toilet, washbowl, bathing, laundry, kitchen, miscellaneous. Flow meters are installed in 140 household selected by sampling in all around Korea. The data are gathered by web-based data collection system from the year 2002 to 2006, considering pre-investigated data such as occupation, revenue, family members, housing types, age, floor area, water saving devices, education, miscellaneous. Reliable data are selected by upper fence method for each observed water use component and statistical characteristics are estimated for each residential type to determine liter per capita per day. Estimated domestic per capita day show an indoor water use with the range from 150 lpcd to 169 lpcd for each housing type as the order of high rise apartment, multi-house, and single house. As the order of consuming amount among water use components, it is investigated that toilet (38.5 lpcd) is the first, and the second is laundry water (30.8 lpcd), the third is kitchen (28.4 lpcd), the fourth is bathtub (24.7 lpcd), the next is washbowl (15.4 lpcd). The results are compared with water uses in U.K. and U.S. As life style has been changed into western style, pattern of water use in Korea is tend to be similar with the U.S. water use pattern. Compared with the surveying results by Bradley, on 1985. Thirty liter of total use increased with the advancement of economic level, and a little change of water use pattern can be found. Especially, toilet water take almost half part of total water use and laundry water shows lowest as 11% in surveying at the year of 1985. But, this study shows that 39 liter, 28% of toilet water, has been decreased by the spread of saving devices and campaign. It is supposed that the spread large sized laundry machine make by-hand laundry has been decreased and water use increased. Unit water amount of each end-use in household can be applied to design factor for water and wastewater facilities, and it play a role as information in establishing water demand forecasting and conservation policy.

• Journal of Korea Water Resources Association
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• v.39 no.12 s.173
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• pp.1057-1066
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• 2006

Water is an indispensable input to human's existence and industrial production. A water supply project would demand considerable costs, but produce economic benefits, which are importantly utilized in the project evaluation. In this situation, this study attempts to value the economic benefits from the residential water supply in Seoul. In particular, yearly consumer surplus and economic value of water supply for eleven water authority agencies in Seoul are measured during the period 2001-2004. Information on price elasticity required in calculating consumer surplus is obtained from direct estimation of the residential water demand function, and the consumer surplus is assessed by using a recently developed formula. Price elasticities used here are -0.810 and -1.011, and the estimated consumer surplus and economic value amount to 131.9 to 164.6 billion won and 398.6 to 431.3 billion won, respectively.

• The Korean Journal of Applied Statistics
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• v.24 no.4
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• pp.567-573
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• 2011

This study develops a predictive model for household water end-uses based on data that have measured household characteristics, housing characteristics and other items, surveyed over 3 years in Korea. However, the measured data was left-skewed and it was not fitted to normal distribution. The parameter estimate were biased when using a multiple regression model. In addition, the results of the testing for the model were usually of significance due to the tiny residual from a large number of observations. In order to solve the problem, we suggested log-normal regression model and Weibull regression model as alternatives. The results of this study can be utilized in the planning stages of water and waste water facilities.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.10
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• pp.656-663
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• 2012

After the construction of waterworks automatic meter reading with 15 mm diameter digital water mater with magnetoresistance sensor developed in this study at 96 households of apartment complexes located in Incheon-City B-Gu S-Dong, the feasibility of field application of waterworks automatic meter reading was evaluated. The field application of waterworks automatic meter reading was performed from July to December in 2011, and average reception rate was as low as 84.6% due to the instable wibro networks, the existence of communication blackout and temporary malfunction of router. After the extraction of 10 households with one to five residents out of 96 households by using stratified random sampling method and analysis of domestic water use, it was found that domestic water use was significant at August and showed a decreasing trend at September, followed by increase in domestic water use at November and decrease in domestic water use at December. This phenomenon should be attributed to weather factors (temperature, humidity, etc.), which significantly affected domestic water use. Similar trend in domestic water use in terms of weather factors was obtained in case of Liter per capita day of water use after the extraction of 30 households out of 96 households by using stratified random sampling method. After analysis of Liter per capita day for 96 households, single residents increases resulted in reduction of domestic water usage by about 14% of Liter per capita day. These results might be due to the fact that domestic water usage such as laundry, beverages, catering, cleaning, etc. should be required for even the household with one resident, whereas domestic water usage for those common utilization can be significantly saved for the household with more than one resident.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1141-1148
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• 2013

End-uses of household water have been influenced by a housing type, life style and housing area which are considered as internal factors. Also, there are external factors such as water rate, weather and water supply facilities. Analysis of influential factors on water consumption in households would give an explanation on the cause of changing trends and would help predicting the water demand of end-use in household. In this paper, we used real data to predict toilet and laundry water-uses and utilized the linear regression model with autoregressive errors. The results showed that the monthly autoregressive error models explained about 71% for describing the water demand of end-use in toilet and laundry water-uses.

• Journal of Korea Water Resources Association
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• v.43 no.11
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• pp.957-965
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• 2010

The municipal water is directly related to the people's quality of life. To examine and implement reasonable water policies including management of the water demand and economically sound investment decisions, it is essential to estimate the conceptually correct and empirically valid economic value of water. This study attempts to estimate the consumer surplus and economic value of municipal water which is supplied to 16 cities in Korea using demand curve approach. The results indicate that the consumer surplus and economic value of municipal water in 2009 are estimated as KRW 1,180.7 per $m^3$ and KRW 1,812.8 per $m^3$, respectively. The economic values of municipal water in 16 cities range from KRW 1,082.7 per $m^3$ to KRW 3,268.6 per $m^3$. Moreover, the economic value of non-residential water is higher than that of residential water in all cities, and the economic value of water is higher than the present price of water. This study is expected to provide policy-makers with useful information to assess a policy and to evaluate the price of water.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.603-614
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• 2008

End-uses of household water have been changed by a life style, housing type, weather, water rate and water supply facilities etc. and those variables can be considered as an internal and exogenous factors to estimate long-term demand forecasts. Analysis of influential factors on water consumption in households would give an explanation to cause on the change of trend and would help predicting the water demand of end-use in household. The purpose of this study is to analyze the demand trends and patterns of household water uses by metering and questionnaire such as occupation, revenue, numbers of family member, housing types, age, floor area and installation of water saving device, etc. The peak water uses were shown at Saturday among weekdays and July in a year based on the analysis results of water use pattern. A steep increase of total water volume can be found in the analysis of water demand trend according to temperature from $-14^{\circ}C$ to $0^{\circ}C$, while there are no significant variations in the phase of more than $0^{\circ}C$, with an almost stable demand. Washbowl water shows the highest and toilet water shows the lowest relation with temperature in correlation analysis results. In the results of ANOVA to find the significant difference in each unit water use by exogenous factors such as housing type, occupation, number of generation, residential area and income et al., difference was shown in bathtub water by housing type and shown in kitchen, toilet and miscellaneous water by numbers of resident. Especially, definite differences in components except washbowl and bathtub water, could be found by numbers of resident. Based on the result, average residents in a house should be carefully considered and the results can be applied as reference information, in decision making process for predicting water demand and establishing water conservation policy. It is expected that these can be used as design factors in planning stage for water and wastewater facilities.

• Journal of Korea Water Resources Association
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• v.44 no.2
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• pp.125-134
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• 2011

The paper is to estimate willingness-to-pay (WTP) for residential water quality improvement in Busan, using non-parametric approach. There are several significant advantages of non-parametric approach, compared to parametric methods. That is, no probability distribution assumption is necessary so that there are no needs to assume or test goodness of fit, model specification and heteroscedasticity statistically. For the reliability and the validity of contingent valuation method a survey was conducted for 665 respondents, who were sampled by stratified random sampling method, by personal interview method. The result of mean WTP for residential water quality improvement in Busan was estimated to be 3,190 won to 3,331 won per month per household, while median WTP being 1,750 won. Provided that our sample is broadly representative of the Busan's population, an estimate of the annual aggregated benefit of residential water improvement for all Busan households is approximately 50.2 billion won in case of mean WTP or 27.5 billion won in case of median WTP.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.121-125
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• 2007

물 수요예측을 실시함에 있어서 사회 경제의 장래동향과 도시의 특성 및 발전 동향을 반영하여 수행하여야 한다. 그러나 지금까지의 관행으로는 수도계획에서 사용할 수 있는 실사용량에 대한 조사와 통계가 이루어지지 않고 있다. 실제 현장에서 얻은 자료를 토대로 하여 수도계획 및 설계에 사용할 수 있는 신뢰성 있는 설계인자의 도출이 필요하다. 본 연구에서는 급수지역의 각 조사 가정의 물 사용량을 실측 조사하여 얻어진 자료를 토대로 하여 물 수요 구조의 변화를 파악할 수 있는 수단의 하나로 가정의 수돗물 사용특성과 경제적 요인에 따른 가정용수의 사용특성 경향을 파악하고자 하였다. 가정에서 사용된 용수량의 조건별 경향성을 분석하기 위하여 한국수자원공사에서 2002년부터 2006년까지 3년여에 걸쳐 표본 집단이 되는 전국 140개 가구에 유량계를 설치하여 유량 자료를 획득하였고, 설문조사를 실시하여 각 가정의 물 사용 특성인자들을 조사하였다. 이 자료를 대상으로 비교적 자료의 신뢰성을 높이기 위한 자료의 선별과정을 거쳤다. 이렇게 선별된 자료들을 경향성 분석에 쓰이는 Mann-Kendall test와 Spearman's Rho test를 이용하여 분석하였다. 그 결과를 바탕으로 가정 용수 소비패턴의 증가 감소에 영향을 끼치는 인자들을 추출하였다. 실측자료를 분석을 통하여 나타난 결과들을 바탕으로 용수 수요처의 조건별 특성을 분석하고, 이를 활용한 생활용수 예측모형을 개발함으로써 합리적인 수요예측에 의한 용수수요의 과다예측 우려를 해소하고, 경제적 수도시설계획을 수립하는 등 과학적 물 수요관리 정책 수립을 위한 의사결정도구가 제공될 수 있다.c}$C의 저온에서 저장한 감자는 $20^{\circ}$C에서 저장한 감자보다 발아의 지연과 함께 낮은 PGA증가율을 보였다.다 높았으며, 전반적인 선호도의 경우 G3(1.5%)를 가장 선호하는 것으로 나타났다. 백년초 분말 첨가 도토리묵의 경우 색상은 0.5% 첨가한 O1이 가장 높은 값을 나타냈으며, 외관은 1.5% 첨가한 O3가 가장 높은 값을 보였다. 향미와 신맛의 경우는 백년초 분말의 첨가량이 증가됨에 따라서 유의적으로 증가했다(p<0.001). 씹힘성, 탄력성, 견고성의 경우는 대조군이 가장 높았으며, 백년초 분말 첨가량이 증가함에 따라 유의적으로 낮아졌다(p<0.001), 떫은맛의 경우는 백년초 분말에 의한 신맛의 영향으로 1% 백년초 분말이 첨가된 O2 가장 높게 나타났다. 전반적인 선호도는 0.5% 백년초 분말이 첨가된 O1이 가장 높게 나타났다. 따라서 녹차와 백년초의 기능성을 살린 도토리묵을 실용화시키는 효과적인 배합비는 녹차 분말 1.5% 첨가와 백년초 분말 첨가 0.5%가 바람직한 것으로 보이며 백년초 분말은 1%까지도 가능한 것으로 나타났다. 그러므로 기능성 식품 소재로써 도토리묵에 녹차와 백년초 분말을 첨가하는 것은 충분히 활용할만한 가치가 있다고 사료된다.론적으로, 비육돈 사료 내 3.32%의 호맥 사일리지의 혼합급여는 혈액 내 코티졸 함량, 도체육의 명도와 황색도, 지방산 조성 및 영양소 소화율에 영향을 미치는 것으로 사료되나 이에 대한 보다 많은 연구가 필요할 것으로 판단된다.니티와 공원과의 관계로 공원 설계와 관리에 있어서 영국에서는 커뮤니티가 직접 고객(client)으로서 역