| publications-4171 |
article |
2002 |
Polycarpou, Marios M. and Polycarpou, Marios M. and Uber, James G. and Uber, James G. and Wang, Zhong and Wang, Zhong and Shao, Feng and Shang, Feng and BrdyΕ›, M. and Brdys, Mietek A. |
Feedback control of water quality |
IEEE Control Systems Magazine |
10.1109/mcs.2002.1004013 |
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Drinking water distribution networks (DWDN) are complex, large-scale systems designed to supply clean water to industrial and domestic users. To reduce the risk of human exposure to pathogens, drinking water is required to contain a small disinfectant residual. The most common disinfectant used in DWDN is chlorine because it is inexpensive and effectively controls a number of disease-causing organisms. The article formulates the water quality control problem and proposes a design approach based on parameter estimation and adaptive control techniques. |
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| publications-4172 |
article |
2014 |
Ohar, Ziv and Ostfeld, Avi |
Optimal design and operation of booster chlorination stations layout in water distribution systems |
Water Research |
10.1016/j.watres.2014.03.070 |
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| publications-4173 |
article |
2014 |
Almalawi, Abdulmohsen and Almalawi, Abdulmohsen and Yu, Xinghuo and Yu, Xinghuo and Tari, Zahir and Tari, Zahir and Tari, Zahir and Tari, Zahir and Fahad, Adil and Fahad, Adil and Khalil, Ibrahim and Khalil, Ibrahim |
An unsupervised anomaly-based detection approach for integrity attacks on SCADA systems |
Computers & Security |
10.1016/j.cose.2014.07.005 |
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| publications-4174 |
article |
2013 |
Hou, Dibo and Hou, Dibo and He, Huimei and He, Huimei and Huang, Pingjie and Huang, Pingjie and Zhang, Guangxin and Zhang, Guangxin and LoΓ΅iciga, Hugo A. and LoΓ΅iciga, Hugo A. |
Detection of water-quality contamination events based on multi-sensor fusion using an extented Dempster–Shafer method |
Measurement Science and Technology |
10.1088/0957-0233/24/5/055801 |
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This study presents a method for detecting contamination events of sources of drinking water based on the Dempster?Shafer (D-S) evidence theory. The detection method has the purpose of protecting water supply systems against accidental and intentional contamination events. This purpose is achieved by first predicting future water-quality parameters using an autoregressive (AR) model. The AR model predicts future water-quality parameters using recent measurements of these parameters made with automated (on-line) water-quality sensors. Next, a probabilistic method assigns probabilities to the time series of residuals formed by comparing predicted water-quality parameters with threshold values. Finally, the D-S fusion method searches for anomalous probabilities of the residuals and uses the result of that search to determine whether the current water quality is normal (that is, free of pollution) or contaminated. The D-S fusion method is extended and improved in this paper by weighted averaging of water-contamination evidence and by the analysis of the persistence of anomalous probabilities of water-quality parameters. The extended D-S fusion method makes determinations that have a high probability of being correct concerning whether or not a source of drinking water has been contaminated. This paper's method for detecting water-contamination events was tested with water-quality time series from automated (on-line) water quality sensors. In addition, a small-scale, experimental, water-pipe network was tested to detect water-contamination events. The two tests demonstrated that the extended D-S fusion method achieves a low false alarm rate and high probabilities of detecting water contamination events. |
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| publications-4175 |
article |
2013 |
Kanta, Lufthansa and Kanta, Lufthansa and Brumbelow, Kelly and Brumbelow, Kelly |
Vulnerability, Risk, and Mitigation Assessment of Water Distribution Systems for Insufficient Fire Flows |
Journal of Water Resources Planning and Management |
10.1061/(asce)wr.1943-5452.0000281 |
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AbstractWater distributions systems must reliably supply water for fire-fighting needs as well as everyday demands but are vulnerable to a range of failure types that can compromise both functions. A methodology is presented integrating failure probability, risk analysis, and optimization of risk that can be used to assess system vulnerabilities and potential mitigation actions. To demonstrate multiple failure mode analysis, three failure types are included: accidental failure due to soil-pipe interaction, accidental failure due to a seismic event, and malevolent attack. A risk-optimization algorithm is implemented using dynamic programming to identify the failure scenarios having the greatest consequences and probability rather than focusing on just one aspect of vulnerability. Finally, potential mitigation strategies are assessed in a benefit-cost-risk reduction analysis. The methodology is intended as a practicable means for infrastructure managers to assess and address system vulnerabilities in a real... |
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| publications-4176 |
article |
2003 |
Boccelli, Dominic L. and Tryby, Michael E. and Uber, James G. and Summers, R. Scott |
A reactive species model for chlorine decay and THM formation under rechlorination conditions. |
Water Research |
10.1016/s0043-1354(03)00067-8 |
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| publications-4177 |
article |
2015 |
Bruch, Elizabeth E. and Bruch, Elizabeth E. and Atwell, Jonathan W. and Atwell, Jon |
AGENT-BASED MODELS IN EMPIRICAL SOCIAL RESEARCH. |
Sociological Methods & Research |
10.1177/0049124113506405 |
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Agent-based modeling has become increasingly popular in recent years, but there is still no codified set of recommendations or practices for how to use these models within a program of empirical research. This article provides ideas and practical guidelines drawn from sociology, biology, computer science, epidemiology, and statistics. We first discuss the motivations for using agent-based models in both basic science and policy-oriented social research. Next, we provide an overview of methods and strategies for incorporating data on behavior and populations into agent-based models, and review techniques for validating and testing the sensitivity of agent-based models. We close with suggested directions for future research. |
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| publications-4178 |
article |
2011 |
Koch, Mark W. and McKenna, Sean A. |
Distributed Sensor Fusion in Water Quality Event Detection |
Journal of Water Resources Planning and Management |
10.1061/(asce)wr.1943-5452.0000094 |
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To protect drinking water systems, a contamination warning system can use in-line sensors to indicate possible accidental and deliberate contamination. Currently, reporting of an incident occurs when data from a single station detects an anomaly. This paper proposes an approach for combining data from multiple stations to reduce false background alarms. By considering the location and time of individual detections as points resulting from a random space-time point process, Kulldorff’s scan test can find statistically significant clusters of detections. Using EPANET to simulate contaminant plumes of varying sizes moving through a water network with varying amounts of sensing nodes, it is shown that the scan test can detect significant clusters of events. Also, these significant clusters can reduce the false alarms resulting from background noise and the clusters can help indicate the time and source location of the contaminant. Fusion of monitoring station results within a moderately sized network show fal... |
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| publications-4179 |
article |
2008 |
Grimm, Nancy B. and Grimm, Nancy B. and Faeth, Stanley H. and Faeth, Stanley H. and Golubiewski, Nancy E. and Golubiewski, Nancy E. and Golubiewski, Nancy and Redman, Charles L. and Redman, Charles L. and Wu, Jianguo and Wu, Jianguo and Bai, Xuemei and Bai, Xuemei and Briggs, John M. and Briggs, John M. |
Global Change and the Ecology of Cities |
Science |
10.1126/science.1150195 |
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Urban areas are hot spots that drive environmental change at multiple scales. Material demands of production and human consumption alter land use and cover, biodiversity, and hydrosystems locally to regionally, and urban waste discharge affects local to global biogeochemical cycles and climate. For urbanites, however, global environmental changes are swamped by dramatic changes in the local environment. Urban ecology integrates natural and social sciences to study these radically altered local environments and their regional and global effects. Cities themselves present both the problems and solutions to sustainability challenges of an increasingly urbanized world. |
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| publications-4180 |
article |
2008 |
Beaudeau, Pascal and de Valk, Henriette and Vaillant, VΓ©ronique and Mannschott, Christian and Tillier, Claude and Mouly, Damien and Ledrans, Martine |
Lessons learned from ten investigations of waterborne gastroenteritis outbreaks, France, 1998-2006. |
Journal of Water and Health |
10.2166/wh.2008.051 |
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Ten outbreaks of waterborne acute gastroenteritis (AGE) have been investigated in France since 1998. These outbreaks have affected populations of over 1,000 people, with generally high attack rates. The causal agents have been identified in six of these events. Aetiologies involved mainly noroviruses and Cryptosporidium sp. The point of entry of the contamination was located in the distribution network in five outbreaks (waste water backflows in four cases and one case of contamination induced by maintenance work) and at the water collection facilities in five other cases. Once the outbreak was detected, epidemiological and environmental investigations and crisis management followed well-established procedures. Further progress in public health surveillance will depend on more complete and rapid detection and reporting. Automated analysis of health insurance data on the reimbursement of drugs for AGE should help make detection more complete. Improved reactivity depends primarily on the operator immediately reporting incidents that indicate a possible massive contamination of the water network to health authorities – in particular complaints from the population, which are the only early-warning alerts in the case of waste water backflows. |
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