Alvin Chew

Dr. Alvin Chew

orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
30 May 2022 in Knowledge-Based Systems
Verified
Journal Article
Closed access
RHRenfei He
Renfei He
Limao ZhangLimao Zhang
Limao Zhang
ACAlvin Chew
Alvin Chew

7 February 2023 in Sustainable Cities and Society
Verified
Journal Article
Closed access
ZWZheng Yi Wu
Zheng Yi Wu
ACAlvin Chew
Alvin Chew
XMXue Meng
Xue Meng
JCJianping Cai
Jianping Cai
JPJocelyn Pok
Jocelyn Pok
JWJia Jie Wong
Jia Jie Wong

24 August 2021 in Knowledge-Based Systems
Verified
Journal Article
Closed access
ACAlvin Chew
Alvin Chew
YPYue Pan
Yue Pan
YWYing Wang
Ying Wang
Limao ZhangLimao Zhang
Limao Zhang

16 December 2021 in Journal of Water Supply: Research and Technology—AQUA
Verified
Journal Article
Open access
PDF file
ZWZheng Yi Wu
Zheng Yi Wu
ACAlvin Chew
Alvin Chew
XMX. Meng
X. Meng
JCJ. Cai
J. Cai
JPJ. Pok
J. Pok
JWJ. J. Wong
J. J. Wong
With increasing adoption of advanced meter infrastructure, smart sensors together with SCADA (Supervisory Control and Data Acquisition) systems, it is imperative to develop novel data analytics and couple the results with hydraulic modeling to improve the quality and efficiency of water services. One important task is to timely detect and localize anomaly events, which may include, but not be limited to, pipe bursts and unauthorized water usages. In this paper, a comprehensive solution framework has been developed for anomaly detection and localization by formulating and integrating data-driven analytics with hydraulic model calibration. Data analysis for anomaly detection proceeds in multiple steps including the following: (1) data pre-processing to eliminate and correct erroneous data records, (2) outlier detection by statistical process control methods and deep machine learning, and (3) system anomaly classification by correlation analysis of multiple sensor events. Classified system anomaly events are subsequently localized via hydraulic model calibration. The integrated solution framework is developed as a user-friendly and effective software tool, tested, and validated on the selected target areas in Singapore.


1 May 2022 in Journal of Water Resources Planning and Management
Verified
Journal Article
Closed access
PDF file
ACAlvin Chew
Alvin Chew
ZWZheng Yi Wu
Zheng Yi Wu
TWThomas Walski
Thomas Walski
XMXue Meng
Xue Meng
JCJianping Cai
Jianping Cai
RKRony Kalfarisi
Rony Kalfarisi
Due to the increasing deployment of sensors in water distribution networks (WDNs) for continuous monitoring, hydrodynamic data are readily available for engineers to improve the daily operations of WDNs. In collaboration with Public Utility Board (PUB), Singapore’s National Water Agency, an alternative model calibration approach using continuously monitored data is proposed to facilitate PUB’s smart water grid (SWG). The generic approach was developed as an integrated solution methodology for practical engineers to conduct a series of systematic analyses daily, namely, (1) estimating the system’s daily nonrevenue water (NRW) volume and NRW time series; (2) adjusting the available pumps’ operational curves and control statuses, followed by calibrating the system’s net demand pattern to fulfill the flow balance accounting for the actual consumption; (3) identifying and rectifying possible offsets in the monitored pressure head values for each sensor station; (4) performing model calibration with anomaly localization analysis when the system’s total NRW volume exceeds its assumed background NRW volume; and (5) calibrating other physical properties to fulfill the system’s energy balance, especially for the peak demand hours. The effectiveness of our proposed approach was then tested and verified using a real-world WDN having total pipe length of >650  km with available monitoring data. Key findings from the case study analysis include (1) anomaly events localized including, but not limited to, five out of six reported leaks for the selected week to within 400 m with lead time of 1–2 days; (2) the system’s initial flow imbalance addressed by estimating the daily NRW volume and localizing the possible anomaly events; and (3) pipe roughness values calibrated to further improve the energy balance in the system, especially during the peak demand hours, by attaining an average mean absolute percentage error (MAPE) score of 2.5%.