상수도관망 재난관리 및 복구를 위한 데이터기반 이상탐지 방법론 개발

정동휘,안재현,Jung, Donghwi,Ahn, Jaehyun 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.8

상수도관의 파열은 과도한 압력, 노후화, 온도변화 나 지진 등에 의한 지반이동에 의해 발생한다. 상수도관 파열이 대규모 단수, 싱크홀 등과 같은 더 심각한 피해 이어지지 않도록 신속하게 탐지 및 대응하는 것이 중요하다. 본 연구에서는 상수도관 파열 탐지를 위해 개선 Western Electric Company (WECO) 방법을 개발하였다. 개선 WECO 방법은 통계적공정관리기법 중 하나인 기존 WECO 방법에 임계치 조정자(w)를 추가하여 대상 네트워크에 적합한 이상탐지 의사결정을 할 수 있도록 했다. 개발된 개선 WECO 방법을 미국 텍사스 오스틴 관망에 적용 및 검증하였다. 상수도관 파열 발생 시 측정한 비정상데이터와 수요량 변동만 고려한 정상데이터를 이용하여 기존 및 개선 WECO 방법을 비교하였다. 최적 임계치 조정자 w값을 결정하기 위해 민감도 분석을 수행하였으며, 다양한 계측시간 간격 데이터(dt = 5, 10, 15분 등)의 영향도 분석하였다. 각 경우 별 탐지성능은 탐지확률, 오경보확률, 평균탐지시간을 계산하여 비교하였다. 본 연구에서는 도출된 결과를 바탕으로 WECO 방법을 실제 상수도관 파열 탐지에 적용하기 위한 가이드라인을 제공한다. Water distribution system (WDS) pipe bursts are caused from excessive pressure, pipe aging, and ground shift from temperature change and earthquake. Prompt detection of and response to the failure event help prevent large-scale service interruption and catastrophic sinkhole generation. To that end, this study proposes a improved Western Electric Company (WECO) method to improve the detection effectiveness and efficiency of the original WECO method. The original WECO method is an univariate Statistical Process Control (SPC) technique used for identifying any non-random patterns in system output data. The improved WECO method multiples a threshold modifier (w) to each threshold of WECO sub-rules in order to control the sensitivity of anomaly detection in a water distribution network of interest. The Austin network was used to demonstrated the proposed method in which normal random and abnormal pipe flow data were generated. The best w value was identified from a sensitivity analysis, and the impact of measurement frequency (dt = 5, 10, 15 min etc.) was also investigated. The proposed method was compared to the original WECO method with respect to detection probability, false alarm rate, and averaged detection time. Finally, this study provides a set of guidelines on the use of the WECO method for real-life WDS pipe burst detection.

토목/건축 분야의 머신러닝 연구 동향 조사

정동휘(Jung, Donghwi),김재현(Kim, Jae Hyun),변용훈(Byun, Yong-Hoon),김승준(Kim, Seung Jun),이종섭(Lee, Jong-Sub) 대한토목학회 2022 대한토목학회 학술대회 Vol.2022 No.10

안전한 지하시설물 관리를 위한 제언

정동휘(Donghwi Jung),이호민(Ho Min Lee),유도근(Do Guen Yoo) 대한토목학회 2019 대한토목학회지 Vol.67 No.4

엘리베이터를 포함한 다층간 지도 작성

정동휘(Donghwi Jung),정용화(Younghwa Jung),허우솔(Woo-Sol Hur),조재경(Jae-Kyung Cho),김성우(Seong-Woo Kim) 대한전자공학회 2022 대한전자공학회 학술대회 Vol.2022 No.6

스마트미터 데이터 활용 방법에 대한 연구

박근영,정동휘,전상훈,Park, Geunyeong,Jung, Donghwi,Jun, Sanghoon 한국수자원학회 2021 한국수자원학회논문집 Vol.54 No.10

This work introduces a new approach that classifies individual household water usage by examining the characteristics of smart meter end-user demand data. Here, one of the most well-known unsupervised machine learning, K-means algorithm, is applied to classify water consumptions by each household. The intensity and duration of end-user demands are used as main features to determine the households with similar water consumption pattern. The results showed that 21 households are classified into 13 clusters with each cluster having one, two, three, or five houses. The reasoning why multiple households are classified into the same cluster is described in this paper with respect to the collected data and end-user water consumption behavior.

상수도 시스템 지진 신뢰성의 합리적 평가를 위한 적정 지반운동예측식 결정

최정욱,강두선,정동휘,이찬욱,유도근,조성배,Choi, Jeongwook,Kang, Doosun,Jung, Donghwi,Lee, Chanwook,Yoo, Do Guen,Jo, Seong-Bae 한국수자원학회 2020 한국수자원학회논문집 Vol.53 No.9

The water supply system has a wider installation range and various components of it than other infrastructure, making it difficult to secure stability against earthquakes. Therefore, it is necessary to develop methods for evaluating the seismic performance of water supply systems. Ground Motion Prediction Equation (GMPE) is used to evaluate the seismic performance (e.g, failure probability) for water supply facilities such as pump, water tank, and pipes. GMPE is calculated considering the independent variables such as the magnitude of the earthquake and the ground motion such as PGV (Peak Ground Velocity) and PGA (Peak Ground Acceleration). Since the large magnitude earthquake data has not accumulated much to date in Korea, this study tried to select a suitable GMPE for the domestic earthquake simulation by using the earthquake data measured in Korea. To this end, GMPE formula is calculated based on the existing domestic earthquake and presented the results. In the future, it is expected that the evaluation will be more appropriate if the determined GMPE is used when evaluating the seismic performance of domestic waterworks. Appropriate GMPE can be directly used to evaluate hydraulic seismic performance of water supply networks. In other words, it is possible to quantify the damage rate of a pipeline during an earthquake through linkage with the pipe failure probability model, and it is possible to derive more reasonable results when estimating the water outage or low-pressure area due to pipe damages. Finally, the quantifying result of the seismic performance can be used as a design criteria for preparing an optimal restoration plan and proactive seismic design of pipe networks to minimize the damage in the event of an earthquake.

송수펌프용량 및 배수지규모에 따른 송·배수시스템의 운영비용 및 체류시간 분석

김강민,최정욱,정동휘,강두선,Kim, Kangmin,Choi, Jeongwook,Jung, Donghwi,Kang, Doosun 한국수자원학회 2017 한국수자원학회논문집 Vol.50 No.12

Recently, various studies have been conducted to optimize the pump operation scheduling and/or the pump/tank size minimizing the system cost of water distribution network. Prior to that, it is important to understand the sensitivity of pump/tank size on the system cost and overall water quality. Here, we have performed the sensitivity analysis to investigate the effect of pump/tank size on the economic cost (construction and operation) and water quality (water age). The analysis was applied on a real, large-scale water transmission network currently operating in South Korea. The results revealed that the pump/tank size has a strong influence on system construction/operation costs. Especially, the tank size has a significant effect on the system-wide water quality. In the case of applied networks, the operating cost decreases as the capacity of the facility increases, but the design cost increases. Using a sensitivity analysis, a suitable range of pump/tank size could be suggested to minimize costs and stabilize the water quality at the same time prior to a system design. 최근 송 배수시스템의 최적 펌프운영과 펌프 및 배수지의 적정용량 산정을 위한 다양한 연구가 진행되고 있다. 시설물의 적정 용량을 선정하기에 앞서 송수펌프 용량 및 배수지규모에 따른 시스템 비용(건설 및 운영비용) 과 시스템 내 수질 변화를 분석하는 과정이 필요하다. 본 연구에서는 민감도 분석을 통해 송수펌프 용량과 배수지의 크기가 실제 시스템의 건설 및 운영비용, 그리고 시스템 전반의 수질에 미치는 영향을 분석하였다. 국내 대규모 지방상수도 시스템을 대상으로 분석을 실시하여 시설물 규모가 비용 및 수질에 미치는 영향을 명확히 파악하였다. 적용 네트워크의 경우, 시설물의 용량이 증가할수록 운영비용은 감소하지만, 설계비용은 증가하는 것으로 나타났으며, 이를 통해 비용최소화와 수질안정화를 동시에 만족하는 시설물의 적정용량 범위를 파악할 수 있을 것으로 판단된다.

적대적 학습 기반 오토인코더(ATAE)를 이용한 다차원 상수도관망 데이터 생성

김세형,전상훈,정동휘,Kim, Sehyeong,Jun, Sanghoon,Jung, Donghwi 한국수자원학회 2023 한국수자원학회논문집 Vol.56 No.7

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.

극한 가뭄상태의 정량적 정의을 위한 포락곡선 방법의 적용

이찬욱(Lee, Chan Wook),정동휘(Jung, Donghwi),박무종(Park, Moo Jong),유도근(Yoo, Do Guen) 한국방재학회 2019 한국방재학회논문집 Vol.19 No.5

최근 기후변화의 영향으로 이전에는 없던 블랙스완형 가뭄재해 발생가능성이 증대되고 있어 이에 대한 맞춤형 대응전략 구축이 필요한 실정이다. 이러한 가뭄은 단순 재난이 아닌 사회전반에 걸쳐 직/간접적인 영향력을 미칠 수 있는 복합형 자연재난이라고 할 수 있다. 본 연구에서는 국내외 문헌 분석을 통해 극한가뭄의 정의사항을 검토하고 극한가뭄이 장기간 지속되는 상태에 대한 정량적인 판단기준 정의를 위한 방법론을 제안 하였다. 국내 과거 주요 가뭄발생 지역에 대한 표준강수지수 를 활용하여 극한가뭄의 누적 가뭄지수 및 지속 기간을 지역 별로 산정하고 포락곡선을 만들어 정량적인 정의 방안을 제시하였다. 산정된 포락곡선은 지역적 또는 전국적 자료의 활용여부에 따라서 그 경향성이 다르게 나타남을 확인할 수 있었다. 향후 본 연구의 정의 사항을 토대로 극한가뭄의 발생 시나리오에 따른 대응기준 설정에 기초자료로 활용 될 수 있을 것으로 기대된다. Recent climate change is causing changes in temperature and rainfall patterns. The frequency of droughts has also steadily increased gradually strengthening the possibility of a Black Swan-type drought; as such, it is necessary to establish a customized response. Such a drought would not just be a disaster, but also a complex natural disaster that could have a direct and indirect impact on society as a whole. Therefore, we consider the definition of extreme drought through analyses of domestic and international literature and propose a methodology to quantitatively determine a domestic definition of extreme drought. Taking advantage of the cumulative Standard Precipitation Index (SPI) index and drought period of a nation s major drought areas, an envelope curve was created to propose a quantitative definition method. In the future, it is expected that the definition of this study will be used as basic data for establishing response criteria based on the scenario of extreme drought.

지진 재해 대응을 위한 진동 기반 구조적 관로 상태 감시 시스템에 대한 고찰

신동협,이정훈,장용선,정동휘,박희등,안창훈,변역근,김영준,Shin, Dong-Hyup,Lee, Jeung-Hoon,Jang, Yongsun,Jung, Donghwi,Park, Hee-Deung,Ahn, Chang-Hoon,Byun, Yuck-Kun,Kim, Young-Jun 대한상하수도학회 2021 상하수도학회지 Vol.35 No.5

As the frequency of seismic disasters in Korea has increased rapidly since 2016, interest in systematic maintenance and crisis response technologies for structures has been increasing. A data-based leading management system of Lifeline facilities is important for rapid disaster response. In particular, the water supply network, one of the major Lifeline facilities, must be operated by a systematic maintenance and emergency response system for stable water supply. As one of the methods for this, the importance of the structural health monitoring(SHM) technology has emerged as the recent continuous development of sensor and signal processing technology. Among the various types of SHM, because all machines generate vibration, research and application on the efficiency of a vibration-based SHM are expanding. This paper reviews a vibration-based pipeline SHM system for seismic disaster response of water supply pipelines including types of vibration sensors, the current status of vibration signal processing technology and domestic major research on structural pipeline health monitoring, additionally with application plan for existing pipeline operation system.