• 상하수도학회지
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• 제37권6호
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• pp.311-324
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• 2023

As an advanced study on the method of calculating the target revenue water ratio of local waterworks through the leakage component analysis method proposed by Kim et al. (2022), this study developed a model to calculate the achievable revenue water ratio within the specified project cost, the required project cost to achieve the specified target revenue water ratio, and the economically appropriate target revenue water ratio level by considering the leakage reduction cost and leakage reduction benefit for each revenue water ratio improvement strategy, and conducted an applicability evaluation of the developed model using actual field data. The procedure for calculating the target revenue water ratio of local waterworks considering economics proposed in this study consists of three stages: physical data linkage model construction, leakage component analysis, and economic analysis, and the applicability was evaluated for Zone H with branch type and the Zone M network type. As a result of the application, it was calculated that approximately 32.5 billion won would be required to achieve the target revenue water ratio of 70% in the Zone H, and approximately KRW 10.5 billion would be required to achieve the target revenue water ratio of 75% in the Zone M. If the business scale of Zones H and M was corrected to 10,000 m³/day of water usage, the required project cost for a 1% improvement in the revenue water ratio of Zone H was calculated to be 0.7642 billion won and 0.4715 billion won for Zone M.

• 한국물환경학회지
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• 제28권2호
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• pp.202-212
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• 2012

Due to the deterioration of water supply network and the deficiency of raw water, the water utility of local governments have performed various projects to improve their revenue water ratio. However, it is very difficult to estimate the cost for maintaining the revenue water ratio at higher level after completing the project, because local governments have different conditions affecting the operating and maintenance cost of water supply network. The purpose of this study is to present a procedure to estimate the operating and maintenance cost required to maintain the target revenue water ratio of the water supply network. For this purpose, we estimated the cost used only for operation and maintenance of water supply network of 164 local governments with the aid of K-Mean Clustering Analysis and the data from 40 representative local governments. Then, the regression analysis was performed to find relationship between revenue water ratio and the operating and maintenance cost with two different data sets generated by two classification methods; the first method classifies the local governments by means of k-means clustering, and the other classifies the local governments according to the index standardized by the operating and maintenance cost per unit length of water mains per revenue water ratio. The results shows that the method based on the index standardized by the cost and revenue water ratio of each government produces more reliable results for finding regression equations between revenue water ratio and the operating and maintenance cost only for water supply network. The estimated regression equations for each group can be used to estimate the cost required to keep the target revenue water ratio of the local government.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.666-669
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• 2017

계측되어 얻어진 유량 값이 잘 보존되고 관리되면 효율적으로 관리가 가능하나, 현행 유수율(유입량, 유출량, 무수량) 업무에서는 유량계의 용도별로 각각의 시스템에서 관리되기 때문에 일괄 자료파악이 어려운 실정이다. 현행 시스템의 문제점을 분석하고, 문제해결을 위한 유수율 통합관리 시스템을 개발, 적용하였으며 이에 따른 효과분석을 제시하였다. 유수율 통합시스템을 통하여 체계적이고 효율적인 유수율 관리와 담당자 업무경감 등을 목적으로 유수율 향상에 기여할 것으로 판단된다.

• 상하수도학회지
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• 제37권6호
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• pp.409-423
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• 2023

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project's target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

• 상하수도학회지
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• 제31권1호
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• pp.51-62
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• 2017

For the asset management of a water pipe network, it would be necessary to understand the extent of the maintenance cost required for the water pipe network for the future. This study would develop a method to draw the optimum cost required for the maintenance of the water pipe network in waterworks facilities to maintain the aim revenue water ratio and to achieve the target revenue water ratio, considering the water service providers' waterworks condition and revenue water ratio comprehensively. This study conducted a survey with 96 water service providers as of the early 2015 and developed models to estimate the optimum maintenance cost of the water pipe network, considering the characteristics of the water service providers. Since the correlation coefficient of all the developed models was higher than 0.95, it turned out that it had significant reliability, which was statistically significant. As a result of applying the developed models to the actual water service providers, it was drawn that increasing revenue water ratio to more than a certain level can reduce the maintenance cost of the water pipe network by a great deal. In other words, it is judged that it would be the most efficient to secure the reliability of waterworks management by increasing the short-term revenue water ratio to more than a certain level and gradually increase the revenue water ratio from the long-term perspective. It is expected that the proposed methodology proposed in this study and the results of the study will be used as a basic research for planning the maintenance of water pipe network or establishing a plan for waterworks facilities asset management.

• 상하수도학회지
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• 제35권2호
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• pp.121-133
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• 2021

This study set up the estimates of leakage management efficiency evaluation and leakage management goal that could be used in local water distribution networks efficiency business and modernization business. The data were analyzed using data envelopment analysis and multiple regression analysis. To this end, with leakage management input indices concerning leakage reduction activities (e.g., aged pipe replacement, water meter replacement, leakage restoration, and leakage detection) and leakage management calculation indices (e.g., the increase of revenue water ratio and the reduction of leakage ratio), the data on 22 K-water consignment local water supply systems were analyzed for the years from 2004 through 2018. Using the results of efficiency analysis by data envelopment analysis, the other DMUs (Decision Making Unit) benchmarked the DMU with the highest efficiency to maximize the leakage management efficiency for all DMUs. Through this, leakage management goal estimates were drawn with the input indices of four leakage reduction activities and calculation indices of the increase of revenue water ratio and the reduction of leakage ratio by multiple regression analysis for each group based on the revenue water ratio and leakage ratio. The correlation coefficients of the leakage management goal estimate for the criteria for the revenue water ratio amounted to 0.553 and 0.771. The correlation coefficients of the leakage management goal estimate for the criteria for leakage ratio were 0.397 and 0.865. Accordingly, we estimated the quantity and priority of four leakage reduction activities for the target leakage ratio and revenue water ratio.

• 상하수도학회지
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• 제31권3호
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• pp.237-248
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• 2017

The estimation method of economical leakage management target utilized upon planning business for improvement of revenue water ratio in South Korea is presented and applicability of methods developed in this study is assessed through application on site. With a consideration of revenue water ratio in application target area, estimation method of long-term economical leakage management target is applied. Three leakage reduction methods such as replacement of residual aged pipe, leakage investigation and restoration and water pressure management are applied with a consideration of characteristics of site. Due to difficulty of obtaining data, analysis of cost/benefit by leakage reduction methods is performed by applying method of leakages estimation equation among statistical methods. As a result of application, revenue water ratio corresponding to long-term economical leakage management target is 91.6 %.

• 상하수도학회지
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• 제35권3호
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• pp.237-246
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• 2021

The ILI, developed by the IWA (International Water Association), has been used in many countries as an indicator of water leakage. In Korea, the revenue water has been used as a performance indicator for waterworks although there is an opinion to replace it with the ILI. Hence, it has been necessary to investigate whether the ILI can replace the revenue water in Korea. The four main operating indicators (i.e., water service population, profit-loss ratio, fiscal self-reliance, and aged pipe rate) of 162 Korean waterworks were compared with the ILI with the linear regression method. Local water authorities with more than 1 million water service population, with more than 60% profit-loss ratio, more than 40% and less than 60% fiscal self-reliance, and more than 20% aged pipe rate showed meaningful correlation between the four parameters and the ILI. In the remaining cases, their correlations were little or weak. This means that using the ILI may not be an efficient method to represent the performance of the water supply system in Korea because of the lack of UARL (Unavoidable Annual Real Losses) data accuracy. To use the ILI in Korea, it will be required to carry out an additional research to accumulate reliable CARL (Current Annual Real Losses) and UARL data in the future.

• 자원ㆍ환경경제연구
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• 제18권4호
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• pp.767-785
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• 2009

본 연구에서는 수질배출부과금제도의 부과체계를 분석하고 개선 방안을 연구하였다. 수질배출부과금제도는 환경오염 원인자에게 처리비용을 부담시켜 환경자원을 효율적으로 사용하도록 하는 경제적 유인 목적을 가지고 있으나 현행 수질배출부과금제도는 행정 규제적 성격이 강하다. 즉, 배출허용기준을 설정하여 이를 위반한 배출업소에 대하여 사업장 규모, 지역, 위반 횟수, 오염물질별 초과율을 고려한 누증적 부과계수를 적용하여 실제 환경오염 비용을 훨씬 초과하는 형벌적 성격의 부과금을 부과하고 있다. 그러나 과도한 부과금 부과로 배출부과금 징수율은 환경관련 부과금 중 가장 낮은 수준이다. 따라서 본 연구에서는 규제적 성격의 부과체계를 개편하여 경제적 유인제도로 수질배출부과금제도를 개편하는 부과체계 개편안을 연구하였으며 이에 따른 부과액 및 징수액 변화 효과를 추정하였다. 추정 결과를 보면 현행 부과금 부과액은 오염물질 처리단가의 약 4배 이상을 부과하고 있어 환경자원의 비효율적 배분을 초래하고 있음을 보여준다. 아울러 과도한 부과금 부과체계를 개선하는 경우에는 징수율도 제고되어 수질배출부과금제도의 기능을 회복할 수 있음을 보여준다.

• 자원ㆍ환경경제연구
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• 제24권1호
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• pp.165-187
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• 2015

본 연구는 수계기금의 환경기초시설 운영비 지원이 지방자치단체의 하수도요금 현실화를 억제하여 수질개선에 역행하는 부작용이 있는지 여부를 분석하는 연구이다. 이를 위해 본 연구에서는 2009~12년 기초지방자치단체의 하수도요금 및 수계기금 지원금 간의 관계를 2단계 최소자승법(Two-Stage Least Squares)을 이용하여 분석하였으며, 이를 통해 수계기금의 환경기초시설 설치 및 운영비용 지원이 하수도요금 현실화를 억제하는 역(逆)인센티브 효과가 있는지 점검하였다. 연구 결과 수계기금 지원금이 하수도요금 현실화 노력에 부정적인 영향을 미치고 있다는 것을 발견하였다. 그러나 이 효과는 통계적인 유의성이 모형에 따라 민감하게 변화하였으며, 전반적으로 그 값이 크지 않아 수계기금의 환경기초시설 설치 운영비 지원이 하수도요금 현실화율에 미치는 영향은 미미하였음을 확인하였다.