• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1307-1311
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• 2005

최근들어 Water Security에 대한 관심이 고조되고 있지만 국내의 경우 이에 대한 체계적인 연구가 아직 진행되지 않았고 상수도관망시스템의 오염예방 및 위험관리에 대한 연구는 매우 미비한 실정이며 특히 상수도관망시스템의 위험성 및 취약성에 대한 연구는 전무한 상태이다. 이러한 상수도관망시스템의 위험도와 관련된 여러 위험요소들은 인명의 피해, 재산상의 피해, 환경적 피해, 시스템의 피해 그리고 사회적 불안등 여러 기준을 고려하여 평가되어야 한다. 이 문제는 다기준의사결정(multi-criteria decision making)문제로서 평가기준들(criteria) 간의 상충관계(trade-off)로 인하여 판단이 모호한 대안들을 PROMETHEE(Preference Ranking Organization METHod Enrichment Evaluations) 기법을 이용하여 평가하였다. PROMETHEE는 선호의 유출량(leaving flow)과 유입량(entering flow)의 개념을 이용하여 여러 대안들의 순위선호(outranking)를 산정하는 기법으로, 의사결정자(decision matter)가 비교적 쉽게 이해할 수 있으며 기존의 AHP$\cdot$ANP와는 달리 명확한 판단이 어려운 대안들에 대해서는 비교불가능한(incomparable) 대안으로 분류한다. 이와 같은 위험도 평가결과는 위기상황에 대한 대처방안을 제시할 의사결정시스템 구축의 기초 자료가 될 수 있을 것이다.

• The Journal of the Korea Contents Association
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• v.6 no.11
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• pp.310-316
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• 2006

Leakage of waterworks pipe line net cause loss of water resources, additional foundation of pressurization facilities from pressure loss and soil weakening near leaked pipe line, etc.. This makes it difficult to maintain and manage waterworks pipe line net and so cause serious economic loss. The rate of accounted water can be improved by monitoring always water pressure and flux, and so on. from isolated region, preparing positively against leakage accident and preventing leakage from occurring. Actually after isolating region, average rate of accounted water in this region went up 88.94% by continuously monitoring control of water pressure and inflow rate. It is about 9.44% higher than that of Busan metropolitan city in 2003, 79.5%.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.401-401
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• 2019

상수관망시스템은 정수처리 된 용수를 수요처에 공급하는 사회기반시설물이며, 주로 지하에 매설되는 시설물의 특성상 관로에 누수가 발생하였을 경우, 정확한 발생지점을 파악하기가 어렵다. 특히, 지진에 의해 시스템 내 다중지점에 누수가 발생할 경우, 장기간 경제적 손실과 사용자의 불편이 예상되므로 신속히 누수지점을 파악한 후, 피해 관로의 적절한 교체 혹은 보수가 이루어져야 한다. 본 연구에서는 지진으로 인해 상수관망에 발생한 다중 누수관로의 정확한 탐지를 위해 다양한 누수탐지 기법을 제안하고 모의결과를 비교, 분석하였다. 가상의 다중 누수 시나리오를 모의한 후, 시스템 내 설치된 수압계와 유량계의 누수발생 전, 후 모니터링 값을 이용하여 1) 최적화 알고리즘을 이용한 Calibration 기법, 2) 수리해석을 통한 누수지점 역추적 기법, 3) 인공신경망을 이용한 Pattern 학습법 등을 적용하였다. 동일한 다중 누수 시나리오를 각 누수탐지 기법에 적용함으로써 누수지점 산정 결과에 대한 정확도를 비교, 분석하였다. 본 연구는 최근 국내에서 발생빈도가 높아지고 있는 지진재해 발생에 대비하여 상수관망시스템의 지진피해 복구 연구를 위해 활용될 수 있을 것으로 기대한다.

• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.291-300
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• 2019

If pipes are damaged in a water distribution network (WDN), adjacent valves are closed to isolate the pipes for repair. Due to the closed valves, parts of WDN are isolated from water supply sources. The isolated area is divided into Intended Isolation Area (IIA) and Unintended Isolation Area (UIA). The IIA occurs by intention to isolate the damaged pipe, while UIA is unintentionally disconnected from the sources due to IIA. Thus, the extension of isolated area and suspended flows are mainly affected by number and location of installed valves in WDN. In this study, optimization models were developed to determine optimal valve locations in WDN. In a single-objective model, total water supply suspension is minimized, while a multi-objective model intends to simultaneously minimize the suspended flow and valve installation cost. Optimal valve placement results obtained from both models were compared and analyzed using a sample application network.

• Journal of Korea Water Resources Association
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• v.39 no.1 s.162
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• pp.35-46
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• 2006

In this study, we proposed a layout of the integrated decision support system in order to prevent the contamination and to manage risk in water supply networks for safe and smooth water supply. We evaluated the priority of risk factors to detect anomaly in water supply networks using PROMETHEE and ANP techniques, which are applied to various Multi-Criteria Decision Making area in Europe and America. To develop the model, we selected pH, residual chlorine concentration, discharge, hydraulic pressure, electrical conductivity, turbidity, block leakage and water temperature as the key data item. We also chose pipe corrosion, pipe burst and water pollution in pipe as the criteria and then we present the results of PROMETHEE and ANP analysis. The evaluation results of the priority of risk factors in water supply networks will provide basic data to establish a contingency plan for accidents so that we can establish the specific emergency response procedures.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.2-2
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• 2019

네팔의 경우 상하수도를 비롯한 기본적인 위생시설이 크게 미비하며 수도인 카트만두조차 수십 년 된 노후관로가 상수관으로 이용되고 있다. 또한, 하수처리 시설이 사실상 전무하며, 지하수를 주요 수원으로 활용하는 대다수 지역은 식수의 오염에 따른 수인성 전염병에 취약한 실정이다. 따라서 네팔에서는 깨끗한 물과 안정적인 수도공급, 하수처리 시설의 확보가 무엇보다 중요한 과제이며, 이에 스마트워터그리드 기술의 도입을 통한 수질개선, 안정적인 수도공급방안이 요구되고 있다. 본 연구에서는 국내에서 개발된 스마트워터그리드 기술을 네팔 소도시에 적용하기 위한 방법론을 제안하였다. 네팔 소도시의 수자원 및 상수도 시설을 답사하여 문제점을 파악하고, 시설 및 운영현황을 분석하였다. 현장조사 자료를 기반으로 스마트워터그리드 기술의 적용 방향과 단기 및 중장기 계획을 제시하였다. 또한, 네팔 소도시 중 하나인 Beni시를 시범지역으로 하여 과거 30년 동안 월 강수량 기반의 가뭄지수를 분석하고, EPANET을 통하여 상수관망해석을 실시였다. 연구 결과, 가뭄의 발생횟수가 점차 빈번해지는 것으로 나타났으며, 상수관망 해석 시 대부분의 수요절점 내 수압이 설계기준보다 낮은 것으로 모의되었고, 향후 관 노후화를 고려한 절점 수압의 확보와 수질개선 방안이 제시될 필요가 있는 것으로 나타났다.

• Journal of Korea Water Resources Association
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• v.56 no.7
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• pp.439-449
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• 2023

Recent advancements in data measuring technology have facilitated the installation of various sensors, such as pressure meters and flow meters, to effectively assess the real-time conditions of water distribution systems (WDSs). However, as cities expand extensively, the factors that impact the reliability of measurements have become increasingly diverse. In particular, demand data, one of the most significant hydraulic variable in WDS, is challenging to be measured directly and is prone to missing values, making the development of accurate data generation models more important. Therefore, this paper proposes an adversarially trained autoencoder (ATAE) model based on generative deep learning techniques to accurately estimate demand data in WDSs. The proposed model utilizes two neural networks: a generative network and a discriminative network. The generative network generates demand data using the information provided from the measured pressure data, while the discriminative network evaluates the generated demand outputs and provides feedback to the generator to learn the distinctive features of the data. To validate its performance, the ATAE model is applied to a real distribution system in Austin, Texas, USA. The study analyzes the impact of data uncertainty by calculating the accuracy of ATAE's prediction results for varying levels of uncertainty in the demand and the pressure time series data. Additionally, the model's performance is evaluated by comparing the results for different data collection periods (low, average, and high demand hours) to assess its ability to generate demand data based on water consumption levels.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.103-116
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• 2005

Although there have been many researches to construct a database of water distribution networks using GIS, most of them were not linked with an model for the analysis of pipe networks because it is difficult to make spatial data about complex water distribution networks for building a detail model. Therefore, it is necessary to develop the method based on GIS to build geographical data for design of water distribution pipeline systems. In this study, an innovated design support technique using GIS is proposed for a hydraulic analysis model of water distribution networks. With the function of spatial analysis in GIS system, the results from a pipe network model are used to analyze the suitability of the location of pipeline network, the spatial suitability comprised the analysis of the degree of pipe age, the altitude distribution of water pressure, and the water supply system for the customer.

• Water for future
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• v.29 no.1
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• pp.141-150
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• 1996

Steady state analysis of pressure and flow in water supply piping systems is a problem of great importance in hydraulic engineering. The basic equations consist of continuity equation and energy equation. The network equations are solved iteratively by using linear solution method. The resulting linear simultaneous equations are solved by frontal method. Frontal method, which is suitable to sparse matrix, gathers only non-zero entries in coefficient matrix. The suggested methodology can analyze faster than the existing routines by using smaller computer memory. The model presented in this study shows accurate and efficient results for various piping systems.

• Journal of Korea Water Resources Association
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• v.52 no.5
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• pp.373-380
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• 2019

In this study, the optimum pump operation technique is suggested to decrease the damage rate of water distribution system. Pump operation system was developed to achieve the effective pump operation. Pressure sensors which can communicate with pumps are installed at the end of water distribution system. Pump operation system can control the pressure of water pump according to data sent from the pressure sensors. Therefore, water distribution system can reduce the pressure and maintain enough pressure which can supply the demand of water users. For proving effectiveness of new system, reliability model was introduced to compare the results of damage rates between the maintaining high pressure and selective pressure in water pump. Unsteady analysis was conducted with several scenarios. And the results were used to calculate the probability of pipe breakage. From the results, it was found that new pump operation system can reduce the energy usage and probability of pipe breakage by applying to pumps.