| publications-3911 |
article |
2009 |
Nazif, Sara and Nazif, Sara and Karamouz, β€Mohammad and Karamouz, Mohammad |
Algorithm for Assessment of Water Distribution System's Readiness: Planning for Disasters |
Journal of Water Resources Planning and Management |
10.1061/(asce)0733-9496(2009)135:4(244) |
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Water distribution systems are one of the most important infrastructures in urban areas. The objective of every urban water distribution system is to deliver enough water of acceptable quality with adequate pressure to different demand points. There are many interruptions and occasional disasters that impact the performance of the water distribution system, some of which could be quite devastating. The most common disasters are main breaks that may cause considerable water losses and bring up the system to partial or complete shutdown. Evaluation of the state of the system's readiness helps managers make better decisions to prevent disasters and respond better to emergencies. In this paper, the state of the system's readiness in dealing with disasters has been quantified using a hybrid index called the system readiness index. This index is developed based on the combined effects of three system performance indexes, namely reliability, resiliency, and vulnerability. They are combined through hydraulic characteristics of the network at some critical nodes of the water distribution system, using a neural network model. Different failure scenarios are defined to evaluate the system performance and to analyze the systems interruption. A Bayesian approach for updating the probability of failure is used to incorporate the new information on the state of the system. The proposed algorithm is applied to a part of the water distribution system of the Tehran metropolitan area in Iran. The results show the significant value of the proposed algorithm in helping the decision maker to improve the system's performance and develop contingency plans when faced with disasters. |
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| publications-3912 |
article |
2015 |
Beal, Cara and Beal, Cara and Flynn, Joe and Flynn, J. |
Toward the digital water age: Survey and case studies of Australian water utility smart-metering programs |
Utilities Policy |
10.1016/j.jup.2014.12.006 |
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The role of ‘smart metering’ in demand management, customer service, labor optimization, and operational efficiency is becoming increasingly recognized by Australasian water utilities. The objectives of this paper are to provide a summary of the 2013 and 2014 surveys and in-depth interviews that were aimed at gauging the penetration of smart metering (SM) and intelligent water network (IWN) projects in Australian and New Zealand water utilities and to identify outputs and challenges faced subsequent to their implementation. |
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| publications-3913 |
article |
2013 |
Britton, Tracy Clare and Britton, Tracy Clare and Stewart, Rodney Anthony and Stewart, Rodney Anthony and O’Halloran, Kelvin and O'Halloran, Kelvin |
Smart metering: enabler for rapid and effective post meter leakage identification and water loss management |
Journal of Cleaner Production |
10.1016/j.jclepro.2013.05.018 |
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Abstract Periods of urban water scarcity in cities places pressure on government agencies and water utilities to improve water distribution system efficiency through reducing the amount of water lost in the network as well as deploying a range of demand management techniques to conserve existing supply. Current estimations assume customer post meter leakage accounts for up to 10\% of total water consumption, particularly in the residential sector. Households identified as having post meter leakage using a citywide installation of smart metering technology were subjected to a mix of basic and tailored information regarding water loss. The primary aim of the study was to test the effectiveness of communication interventions and the attributed water savings resulting from the repair of household leaks. The residential leakage communication strategy resulted in a reduction in minimum night flows by a very significant 89\% over the duration of the study, while the control group receiving no communication increased consumption by 52\%. Moreover, questionnaire surveys were conducted to establish the significant factors, including leak type, demographics and household awareness, to name a few, that will influence the development of a fit-for-purpose post-meter leak rectification policy and program. The paper concludes with some key recommendations for future work to develop a predictive model for identifying, classifying and quantifying post meter loss as well as presents least cost planning implications of a leak rectification policy. The study confirmed that smart metering provides water utilities with a powerful tool to rapidly identify and action the significant volumes of post meter leakage occurring in our cities. |
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| publications-3914 |
article |
2009 |
Savić, Dragan and Savic, Dragan and Kapelan, Zoran and Kapelan, Zoran and Jonkergouw, Philip and Jonkergouw, Philip |
Quo vadis water distribution model calibration |
Urban Water Journal |
10.1080/15730620802613380 |
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Hydraulic water distribution system (WDS) simulation models are widely used by planners, water utility personnel, consultants and many others involved in analysis, design, operation or maintenance of water distribution systems. Similarly, water quality models that work in concert with hydraulic models are now commonly used to simulate the dispersion of and changes in water quality in a water distribution network. As with all mathematical models, WDS model parameters (hydraulic and water quality) require calibration before useful results may be obtained. Nowadays, automated calibration procedures are widely available for hydraulic models, but less so for water quality models. Even when they are available as commercial software, the use of these advanced calibration tools in engineering practice has been limited. This paper provides a review of model calibration approaches and considers future challenges and directions. |
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| publications-3915 |
article |
2008 |
Preis, Ami and Ostfeld, Avi |
Genetic algorithm for contaminant source characterization using imperfect sensors |
Civil Engineering and Environmental Systems |
10.1080/10286600701695471 |
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Abstract A simple, straightforward, modified genetic algorithm scheme for contaminant source characterization using imperfect sensors is presented and demonstrated in this study. Previous work on this subject concentrated on developing source-inversion models using sensors that provide accurate, unbiased, contamination concentration measurements. The developed contamination source-detection model is implemented using three sensor types: (1) perfect sensors providing accurate, unbiased, contamination concentration measurements; (2) sensors transmitting fuzzy measured information (i.e., high, medium, and low contamination); and (3) ‘0–1’ (Boolean) sensors indicating only a contamination presence. A comparison between the three sensor types is explored taking into consideration thesystem's response time (i.e., the time elapsed between a contaminant detection and a decision-maker's response action). The methodology capabilities are demonstrated using two example applications of increasing complexity, showing ... |
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| publications-3916 |
article |
2012 |
Ostfeld, Avi and Ostfeld, Avi and Salomons, Elad and Salomons, Elad and Ormsbee, Lindell and Ormsbee, Lindell and Uber, James G. and Uber, James G. and Bros, Christopher M. and Bros, Christopher M. and Kalungi, Paul and Kalungi, Paul and Burd, Richard and Burd, Richard and Zazula-Coetzee, Boguslawa and Zazula-Coetzee, Boguslawa and Belrain, Teddy and Belrain, Teddy and Kang, Doosun and Kang, Doosun and Lansey, Kevin and Lansey, Kevin E and Shen, Hailiang and Shen, Hailiang and McBean, Edward and McBean, Edward A. and Wu, Zheng Yi and Wu, Zheng Yi and Walski, Tom and Walski, Thomas M. and Alvisi, Stefano and Alvisi, Stefano and Franchini, Marco and Franchini, Marco and Johnson, Joshua P. and Johnson, Joshua P. and Ghimire, Santosh R. and Ghimire, Santosh R. and Barkdoll, Brian D. and Barkdoll, Brian D. and Koppel, Tarmo and Koppel, T. and Vassiljev, Anatoli and Vassiljev, Anatoli and Kim, Joong Hoon and Kim, Joong Hoon and Kim, Joong Hoon and Chung, Gunhui and Chung, Gunhui and Chung, Gunhui and Yoo, Do Guen and Yoo, Do Guen and Diao, Kegong and Diao, Kegong and Zhou, Yue and Zhou, Yuwen and Ji, Li and Li, Ji and Li, Ji and Liu, Zilong and Liu, Zilong and Chang, Kui and Chang, Kui and Chang, Kui and Gao, Jinliang and Gao, Jinliang and Gao, Jinliang and Qu, Shaojian and Qu, Shaojian and Yuan, Yixing and Yuan, Yixing and Prasad, T. Devi and Prasad, T. Devi and Prasad, T. Devi and Laucelli, Daniele Biagio and Laucelli, Daniele B. and Vamvakeridou, L. and Vamvakeridou, Lydia S. Lyroudia and Kapelan, Zoran and Kapelan, Zoran and Savić, Dragan and Savic, Dragan and Berardi, Luigi and Berardi, Luigi and Berardi, Luigi and Barbaro, Giuseppe and Barbaro, Giuseppe and Giustolisi, Orazio and Giustolisi, Orazio and Asadzadeh, Masoud and Asadzadeh, Masoud and Tolson, Bryan A. and Tolson, Bryan A. and McKillop, Robert and McKillop, R. |
Battle of the Water Calibration Networks |
Journal of Water Resources Planning and Management |
10.1061/(asce)wr.1943-5452.0000191 |
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Abstract Calibration is a process of comparing model results with field data and making the appropriate adjustments so that both results agree. Calibration methods can involve formal optimization methods or manual methods in which the modeler informally examines alternative model parameters. The development of a calibration framework typically involves the following: (1)definition of the model variables, coefficients, and equations; (2)selection of an objective function to measure the quality of the calibration; (3)selection of the set of data to be used for the calibration process; and (4)selection of an optimization/manual scheme for altering the coefficient values in the direction of reducing the objective function. Hydraulic calibration usually involves the modification of system demands, fine-tuning the roughness values of pipes, altering pump operation characteristics, and adjusting other model attributes that affect simulation results, in particular those that have significant uncertainty assoc... |
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| publications-3917 |
article |
2007 |
Rowley, Jennifer and Rowley, Jennifer |
The wisdom hierarchy: representations of the DIKW hierarchy |
Journal of Information Science |
10.1177/0165551506070706 |
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This paper revisits the data-information-knowledge-wisdom (DIKW) hierarchy by examining the articulation of the hierarchy in a number of widely read textbooks, and analysing their statements about the nature of data, information, knowledge, and wisdom. The hierarchy referred to variously as the 'Knowledge Hierarchy', the 'Information Hierarchy' and the 'Knowledge Pyramid' is one of the fundamental, widely recognized and 'taken-for-granted' models in the information and knowledge literatures. It is often quoted, or used implicitly, in definitions of data, information and knowledge in the information management, information systems and knowledge management literatures, but there has been limited direct discussion of the hierarchy. After revisiting Ackoff's original articulation of the hierarchy, definitions of data, information, knowledge and wisdom as articulated in recent textbooks in information systems and knowledge management are reviewed and assessed, in pursuit of a consensus on definitions and transformation processes. This process brings to the surface the extent of agreement and dissent in relation to these definitions, and provides a basis for a discussion as to whether these articulations present an adequate distinction between data, information, and knowledge. Typically information is defined in terms of data, knowledge in terms of information, and wisdom in terms of knowledge, but there is less consensus in the description of the processes that transform elements lower in the hierarchy into those above them, leading to a lack of definitional clarity. In addition, there is limited reference to wisdom in these texts. |
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| publications-3918 |
article |
2015 |
Schwaller, J. and Schwaller, J. and van Zyl, J. E. and van Zyl, J. E. |
Modeling the Pressure-Leakage Response of Water Distribution Systems Based on Individual Leak Behavior |
Journal of Hydraulic Engineering |
10.1061/(asce)hy.1943-7900.0000984 |
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AbstractPressure management has been used for more than 3 decades to reduce leakage from water distribution systems. While few of these studies have been published, information on the ranges of field study leakage exponents is available. In contrast, several studies on the pressure-leakage relationship of individual leaks have been published, and verified models have been developed for predicting the response of elastically deforming leaks. The main aim of this paper was to determine whether researchers’ current understanding of the pressure-leakage response of individual leaks can be reconciled with the observed pressure-leakage response of district metered areas containing many leaks. To investigate this, a model of the distribution of individual leaks and their parameters was developed based on available literature and expert advice. A repeatability study showed that such a model can indeed produce typical distributions of leakage exponents found in field studies. A sensitivity analysis of the various ... |
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| publications-3919 |
article |
2006 |
Gerla, Giangiacomo and Gerla, Giangiacomo and Gerla, Giangiacomo |
Effectiveness and multivalued logics |
Journal of Symbolic Logic |
10.2178/jsl/1140641166 |
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Effective domain theory is applied to fuzzy logic. The aim is to give suitable notions of semi-decidable and decidable L -subset and to investigate about the effectiveness of the fuzzy deduction apparatus. |
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| publications-3920 |
article |
2014 |
Giustolisi, Orazio and Giustolisi, Orazio and Berardi, Luigi and Berardi, Luigi and Laucelli, Daniele Biagio and Laucelli, Daniele B. |
Modeling Local Water Storages Delivering Customer Demands in WDN Models |
Journal of Hydraulic Engineering |
10.1061/(asce)hy.1943-7900.0000812 |
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Water distribution network (WDN) models account for customer-demands as water withdrawals concentrated in nodes. Customer- demands can be assumed to be constant or varying with nodal head/pressure entailing demand-driven or pressure-driven simulation, respec- tively. In both cases, the direct connection of customer properties to the hydraulic system is implicitly assumed. Nonetheless, in many technical situations, the service pipe fills a local private storage (e.g., a roof tank or a basement tank) from which the water is actually delivered to customers by gravity or pumping systems. In such contexts, the service pipe fills the local tank by means of a top orifice. Consequently, what is really connected to the hydraulic system is a tank, which is subject to a filling/emptying process while supplying water to customers. Therefore, since modeling this technical situation in WDN analyses is necessary, the paper develops a formulation for nodal water withdrawals in WDN models accounting for the filling/emptying process of inline tanks between the hydraulic network and customers. The formulation is also introduced in a widely used method for steady-state WDN modeling, the global gradient algorithm, and its effectiveness to increase the hydraulic accuracy of results is discussed using a simple case study and a small network. DOI: 10.1061/(ASCE) HY.1943-7900.0000812. Β© 2014 American Society of Civil Engineers. Author keywords: Tank modeling; Water distribution networks; Hydraulic network modeling; Water distribution network simulation; Extended period simulation. |
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