• 상하수도학회지
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• 제26권5호
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• pp.693-703
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• 2012

Leakage in water supply system can cause water resources loss in addition to the water quality degradation. In this research, leakage reduction after establishment of a block system in the area with leakage rate of 69.0 % was investigated using EPANET simulation. The average water pressure for the research area was $5.17kgf/cm^2$ which was relatively high, and several sites were deviated from recommended water pressure ranges(i.e., 1.5 ~ $7.1kgf/cm^2$). However, the average water pressure in the area was reduced to 3.81 and $3.49kgf/cm^2$ after the introduction of block system with a water pressure relief valve(PRV) setting of 3.0 and $2.5kgf/cm^2$, respectively. Under the installation of a PRV with regulating pressure of $2.5kgf/cm^2$, the predicted leakage was reduced from $4,420.3m^3/d$ to $3,028.1m^3/d$, which was equivalent to the leakage reduction from 31.0 % to 23.5 %.

• Earthquakes and Structures
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• 제16권6호
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• pp.727-741
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• 2019

A reinforced concrete water tank is a typical functional liquid storage structure and cracks are the greatest threat to the liquid storage structure. Tanks are readily cracked due to seismic activity, thereby leading to the leakage of the stored liquid and a loss of function. In order to study the effect of cracks on liquid storage tanks, self-healing and leakage tests for bending cracks and through cracks in the walls of a reinforced concrete water tank were conducted. Material performance tests were also performed. The self-healing performance of bending cracks in a lentic environment and through cracks in a lotic environment were tested, thereby the self-healing width of bending micro-cracks in the lentic environment in the short term were determined. The through cracks had the capacity for self-healing in the lotic environment was found. The leakage characteristics of the bending cracks and through cracks were tested with the actual water head on the crack. The effects on liquid leakage of the width of bending cracks, the depth of the compression zone, and the acting head were determined. The relationships between the leakage rate and time with the height of the water head were analyzed. Based on the tests, the relationships between the crack characteristics and self-healing as well as the leakage were obtained. Thereby the references for water tank structure design and grading earthquake damage were provided.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
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• pp.117-121
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• 2006

This study intends to suggest the effective methods for water leakage prevention around the windows in stone works to up-grade the outdoor public space that has been taken much portion of apartment housing trends. The subjects of the study was selected among the domestic subcontractors of stone works. There are four methods for water leakage prevention around the windows; Firstly, the painting water-proof method after the masonry. Secondly, the urethane water-proof method after galvanizing panels on the gap. Thirdly, the separation method between stone and substructure and the last one is water-proof method that they put some water-proof screen between stone and substructure with the EPDM sheets. According to the analysis of the water-proof effects, constructability and planning, we could approach to conclusion that the most influent items to the water-leakage are the filling material's deformation, the state of oxygenation and deterioration of work skill. Among the water-proof methods in construction the EPDM sheet is most excellent water-proof method to meet the technical conditions. However, we have to apply it to stone works as a water-proof method for the decrease of the leakage defects after standardizing the materials, test and construction skill because there are many work skills according the subcontractors.

• 한국수자원학회논문집
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• 제56권10호
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• pp.679-690
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• 2023

누수는 용수공급시스템 내에서 발생할 수 있는 대표적인 비정상상황 중 하나이다. 누수는 관로가 매설된 이후부터 잠재적으로 발생할 수 있으며 발생 직후부터 즉시 경제적 및 수리학적 피해를 입을 수 있기 때문에 이를 적시에 감지하고 탐지하는 것이 중요하다. 하지만 시스템이 지하에 매설되어 있어 이를 빠르게 인지하는 것은 쉽지 않으며 인지한다 하여도 복구하기 위해서는 상대적으로 많은 가용자산이 요구된다. 따라서 다중 누수가 발생할 시 누수규모 및 위치에 따라 복구 우선순위에 대한 우선순위를 선정해야 할 필요성이 있으며 최적의 복구전략이 도출되어 이를 수행할 시 시스템의 탄력성 측면에 있어 유리함을 가질 수 있다. 본 연구에서는 프로그램 기반 모의 누수를 발생시켜 비정상상황 시나리오를 구축하였으며 이에 따라 딥러닝 기반 모델로 누수탐사를 수행하였다. 탐사 결과로 얻어지는 누수위치와 누수량은 이 후 누수복구 우선순위를 위한 요소로써 활용되며 타 요소와 함께 최적의 누수복구 시나리오를 도출하였다.

• 한국전기전자재료학회논문지
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• 제25권10호
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• pp.817-823
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• 2012

Insulation breakdown of water-cooled generator stator windings occurs frequently due to leakage of cooling water and absorption into the insulation material. Leakage and absorption problems of water-cooled stator windings are often found during regular preventive maintenance. To evaluate cooling water leakage and absorption, diagnostic tests were performed on two water-cooled turbine generators, which have been in service for 13 and 17 years, respectively. The test results of the measured electrical properties such as dissipation factor($tan{\delta}$), capacitance and AC leakage current for water-cooled generator stator windings with wet bars are reported in this paper.

• 한국콘텐츠학회논문지
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• 제13권1호
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• pp.48-54
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• 2013

IT융합기술의 발전에 따라 누수탐지를 위한 인프라스트럭처가 구축되면서, 파손된 관로의 위치 및 규모의 파악 기술이 부각되고 있다. 또한 상수도 시설의 누수로 인한 수자원의 고갈 때문에 효율적으로 누수를 탐지할 수 있는 방법이 시급하다. 본 논문에서는 파워스펙트럼 분석을 이용한 누수탐지 모니터링 시뮬레이션을 제안하였다. 제안한 누수탐지 모니터링 시뮬레이션에서 반사파 파형을 측정한다. 수집된 반사파 파형으로부터 변화율을 계산한다. 그리고 고속 퓨리에 변환을 이용한 파워 스펙트럼 분석은 누수의 크기와 반사파 파형의 상관관계를 평가한다. 이를 시뮬레이션의 논리적 타당성과 유효성을 검증하기 위해 실험적인 적용을 시도하고자 한다. 따라서 실시간 누수탐지를 제공하여 효율적인 관리에 대한 만족도와 서비스의 질을 향상시켰다.

• 한국수자원학회논문집
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• 제56권5호
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• pp.347-356
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• 2023

상수도시스템에서는 적수 및 누수와 같은 다양한 수리 및 수질적 비정상상황이 발생한다. 이를 방지하거나 빠르게 복구하기 위하여 다양한 계측기에서 얻어지는 데이터를 통해 사고를 예상하고 탐지한다. 하지만 대표적인 수리학적 비정상상황인 누수의 경우 직접적인 탐사를 수행하지 않는다면 발견되기 어렵다. 그 중 미신고 파열누수의 경우 육안식별이 어렵기 때문에 가장 많은 누수를 차지하게 되며 이는 곧 큰 경제적 손실로 이어진다. 직접적인 탐사의 경우 전문인력 확보 등 현장의 여건 등 여러 한계점이 존재한다. 이를 해결하기 위해 본 연구에서는 검보정이 완료된 상수도관망 수리모형(EPANET)의 수리해석결과 데이터를 학습데이터로 사용하고 Deep neural network 알고리즘을 활용하여 누수규모 및 누수위치에 대한 누수탐사를 수행하였다. 누수탐사 수행을 위해 모의 누수 사고데이터를 생성하였으며 누수규모, 위치 등 다양한 시나리오를 고려하였다. 또한, 최적의 누수 탐지 성능을 위해 관망의 크기, 계측기의 종류, 개수, 위치에 따른 탐지성능을 분석하였다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.1-11
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• 2020

In this study, leakage ratios of Jeju Island's public agricultural groundwater were calculated by utilizing field measurements of groundwater level and surface reservoir water level. The average leakage ratios were 75.6% at groundwater well A and 57.5% at well B, with the ratio inversely proportional to agricultural water usage. The level of agricultural reservoirs varied at constant intervals at night, and the amount of water leakage associated with the variation was estimated as 0.1 - 16.3 ㎥/h. The leakage ratio was also influenced by pipeline length, average slope, and number of farmhouses. Currently, the estimation of agricultural water leakage on Jeju Island is based upon field inspection which is very labor- and cost intensive. The leakage ratio estimated by monitoring the reservoirs associated with the well A and B were 73.3 and 54.7%, respectively, consistent with the values obtained by field measurements.

• 상하수도학회지
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• 제22권1호
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• pp.149-157
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• 2008

The reduction of leakage is a major issue of the South Korea water industry. The inclusion of pressure dependent leakage terms in network analysis allows the application of optimization techniques to identify the most effective means of reducing water leakage in distribution networks. This paper proposes a method to find optimal setting and location of control valve for reducing leakage efficiently. The proposed search method differs from previous methods for addressing optimal valve location problem and improves the GA simulation time with guaranteeing for getting the global optimal solution. The strength of this method has been demonstrated by means of case studies. This allows the procedure of optimization to be more robust and computational efficient.

• 한국안전학회지
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• 제14권1호
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• pp.66-72
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• 1999

Local heating transportation pipe has sensor and return lines to detect water-leakage. There are impulse and resistance comparison measurement types for a water-leakage detection. The impulse type shows large detection error within a measurement range. Since the resistance comparison type can find a comparative accurate single water-leakage point in the measurement range of heating pipe, it has been used to detect water-leakages these days. However if the multi water-leakages are happened in the measurement range of transportation pipe. the resistance comparison type shows a detection error point by the parallel resistance between a detection sensor line and ground. But the detection error will be minimized by the divided transportation pipe loops. In this research, it suggests the design of remote controlled detection system which can divide a large pipe loop and a possible single water-leakage measurement process in each divided loops.