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Gustavo Meirelles Lima
Fluing-Institute for Multidisciplinary Mathematics, Universitat Politècnica de València, 46022 Valencia, Spain

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Journal article
Published: 14 March 2021 in Water
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Service quality and efficiency of urban systems have been dramatically boosted by various high technologies for real-time monitoring and remote control, and have also gained privileged space in water distribution. Monitored hydraulic and quality parameters are crucial data for developing planning, operation and security analyses in water networks, which makes them increasingly reliable. However, devices for monitoring and remote control also increase the possibilities for failure and cyber-attacks in the systems, which can severely impair the system operation and, in extreme cases, collapse the service. This paper proposes an automatic two-step methodology for cyber-attack detection in water distribution systems. The first step is based on signal-processing theory, and applies a fast Independent Component Analysis (fastICA) algorithm to hydraulic time series (e.g., pressure, flow, and tank level), which separates them into independent components. These components are then processed by a statistical control algorithm for automatic detection of abrupt changes, from which attacks may be disclosed. The methodology is applied to the case study provided by the Battle of Attack Detection Algorithms (BATADAL) and the results are compared with seven other approaches, showing excellent results, which makes this methodology a reliable early-warning cyber-attack detection approach.

ACS Style

Bruno Brentan; Pedro Rezende; Daniel Barros; Gustavo Meirelles; Edevar Luvizotto; Joaquín Izquierdo. Cyber-Attack Detection in Water Distribution Systems Based on Blind Sources Separation Technique. Water 2021, 13, 795 .

AMA Style

Bruno Brentan, Pedro Rezende, Daniel Barros, Gustavo Meirelles, Edevar Luvizotto, Joaquín Izquierdo. Cyber-Attack Detection in Water Distribution Systems Based on Blind Sources Separation Technique. Water. 2021; 13 (6):795.

Chicago/Turabian Style

Bruno Brentan; Pedro Rezende; Daniel Barros; Gustavo Meirelles; Edevar Luvizotto; Joaquín Izquierdo. 2021. "Cyber-Attack Detection in Water Distribution Systems Based on Blind Sources Separation Technique." Water 13, no. 6: 795.

Special issue paper
Published: 11 January 2021 in Mathematical Methods in the Applied Sciences
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The design of district metered areas (DMA) in potable water supply systems is of paramount importance for water utilities to properly manage their systems. Concomitant to their main objective, namely, to deliver quality water to consumers, the benefits include leakage reduction and prompt reaction in cases of natural or malicious contamination events. Given the structure of a water distribution network (WDN), graph theory is the basis for DMA design, and clustering algorithms can be applied to perform the partitioning. However, such sectorization entails a number of network modifications (installing cut‐off valves and metering and control devices) involving costs and operation changes, which have to be carefully studied and optimized. Given the complexity of WDNs, optimization is usually performed using metaheuristic algorithms. In turn, optimization may be single or multiple‐objective. In this last case, a large number of solutions, frequently integrating the Pareto front, may be produced. The decision maker has eventually to choose one among them, what may be tough task. Multicriteria decision methods may be applied to support this last step of the decision‐making process. In this paper, DMA design is addressed by (i) proposing a modified k‐means algorithm for partitioning, (ii) using a multiobjective particle swarm optimization to suitably place partitioning devices, (iii) using fuzzy analytic hierarchy process (FAHP) to weight the four objective functions considered, and (iv) using technique for order of preference by similarity to ideal solution (TOPSIS) to rank the Pareto solutions to support the decision. This joint approach is applied in a case of a well‐known WDN of the literature, and the results are discussed.

ACS Style

Bruno M. Brentan; Silvia Carpitella; Joaquín Izquierdo; Edevar Luvizotto Jr; Gustavo Meirelles. District metered area design through multicriteria and multiobjective optimization. Mathematical Methods in the Applied Sciences 2021, 1 .

AMA Style

Bruno M. Brentan, Silvia Carpitella, Joaquín Izquierdo, Edevar Luvizotto Jr, Gustavo Meirelles. District metered area design through multicriteria and multiobjective optimization. Mathematical Methods in the Applied Sciences. 2021; ():1.

Chicago/Turabian Style

Bruno M. Brentan; Silvia Carpitella; Joaquín Izquierdo; Edevar Luvizotto Jr; Gustavo Meirelles. 2021. "District metered area design through multicriteria and multiobjective optimization." Mathematical Methods in the Applied Sciences , no. : 1.

Journal article
Published: 13 August 2020 in Processes
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Agent-based algorithms, based on the collective behavior of natural social groups, exploit innate swarm intelligence to produce metaheuristic methodologies to explore optimal solutions for diverse processes in systems engineering and other sciences. Especially for complex problems, the processing time, and the chance to achieve a local optimal solution, are drawbacks of these algorithms, and to date, none has proved its superiority. In this paper, an improved swarm optimization technique, named Grand Tour Algorithm (GTA), based on the behavior of a peloton of cyclists, which embodies relevant physical concepts, is introduced and applied to fourteen benchmarking optimization problems to evaluate its performance in comparison to four other popular classical optimization metaheuristic algorithms. These problems are tackled initially, for comparison purposes, with 1000 variables. Then, they are confronted with up to 20,000 variables, a really large number, inspired in the human genome. The obtained results show that GTA clearly outperforms the other algorithms. To strengthen GTA’s value, various sensitivity analyses are performed to verify the minimal influence of the initial parameters on efficiency. It is demonstrated that the GTA fulfils the fundamental requirements of an optimization algorithm such as ease of implementation, speed of convergence, and reliability. Since optimization permeates modeling and simulation, we finally propose that GTA will be appealing for the agent-based community, and of great help for a wide variety of agent-based applications.

ACS Style

Gustavo Meirelles; Bruno Brentan; Joaquín Izquierdo; Jr. Edevar Luvizotto. Grand Tour Algorithm: Novel Swarm-Based Optimization for High-Dimensional Problems. Processes 2020, 8, 980 .

AMA Style

Gustavo Meirelles, Bruno Brentan, Joaquín Izquierdo, Jr. Edevar Luvizotto. Grand Tour Algorithm: Novel Swarm-Based Optimization for High-Dimensional Problems. Processes. 2020; 8 (8):980.

Chicago/Turabian Style

Gustavo Meirelles; Bruno Brentan; Joaquín Izquierdo; Jr. Edevar Luvizotto. 2020. "Grand Tour Algorithm: Novel Swarm-Based Optimization for High-Dimensional Problems." Processes 8, no. 8: 980.

Journal article
Published: 01 January 2020 in RBRH
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The optimization of pumping stations operation in water distribution networks has been largely studied, especially with the development of speed drivers, which allowed the machines to adjust the hydraulic power inserted to the system according to the demand requirements. Although this approach results in high benefits, the original characteristics of pumps remains the same. Consequently, the pumps can be operating in a range of suboptimal efficiency. Thus, this paper will evaluate the benefits that an optimized pump selection can bring for variable speed operation. The selection of the pumps best efficiency point and the number of pumps operating in parallel are defined applying Particle Swarm Optimization (PSO) to minimize the energy costs of the system. For the case study, the results show that there is no benefit when more pumps are operated in parallel, and that a flexible operational routine significantly reduces the energy expenses, especially when the pump is selected for this purpose.

ACS Style

Débora Salomé Móller; Gustavo Meirelles Lima; Bruno Melo Brentan; Daniel Bezerra Barros. Optimal pump selection for variable speed operation in water distribution network. RBRH 2020, 25, 1 .

AMA Style

Débora Salomé Móller, Gustavo Meirelles Lima, Bruno Melo Brentan, Daniel Bezerra Barros. Optimal pump selection for variable speed operation in water distribution network. RBRH. 2020; 25 ():1.

Chicago/Turabian Style

Débora Salomé Móller; Gustavo Meirelles Lima; Bruno Melo Brentan; Daniel Bezerra Barros. 2020. "Optimal pump selection for variable speed operation in water distribution network." RBRH 25, no. : 1.

Journal article
Published: 30 October 2019 in Water
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A large volume of the water produced for public supply is lost in the systems between sources and consumers. An important—in many cases the greatest—fraction of these losses are physical losses, mainly related to leaks and bursts in pipes and in consumer connections. Fast detection and location of bursts plays an important role in the design of operation strategies for water loss control, since this helps reduce the volume lost from the instant the event occurs until its effective repair (run time). The transient pressure signals caused by bursts contain important information about their location and magnitude, and stamp on any of these events a specific "hydraulic signature". The present work proposes and evaluates three methods to disaggregate transient signals, which are used afterwards to train artificial neural networks (ANNs) to identify burst locations and calculate the leaked flow. In addition, a clustering process is also used to group similar signals, and then train specific ANNs for each group, thus improving both the computational efficiency and the location accuracy. The proposed methods are applied to two real distribution networks, and the results show good accuracy in burst location and characterization.

ACS Style

Daniel Manzi; Bruno Brentan; Gustavo Meirelles; Joaquín Izquierdo; Jr. Edevar Luvizotto. Pattern Recognition and Clustering of Transient Pressure Signals for Burst Location. Water 2019, 11, 2279 .

AMA Style

Daniel Manzi, Bruno Brentan, Gustavo Meirelles, Joaquín Izquierdo, Jr. Edevar Luvizotto. Pattern Recognition and Clustering of Transient Pressure Signals for Burst Location. Water. 2019; 11 (11):2279.

Chicago/Turabian Style

Daniel Manzi; Bruno Brentan; Gustavo Meirelles; Joaquín Izquierdo; Jr. Edevar Luvizotto. 2019. "Pattern Recognition and Clustering of Transient Pressure Signals for Burst Location." Water 11, no. 11: 2279.

Journal article
Published: 01 January 2019 in Revista DAE
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O dimensionamento de redes de distribuição de água (RDAs) é feito para que as restrições operacionais de velo- cidade e pressão se mantenham dentro de limites que garantam a eficiência operacional. Assim, buscam-se as tubulações de menor custo para que essas condições sejam satisfeitas. Entretanto, ao adotar essa prática, ou- tras características da rede podem ser afetadas negativamente, como sua resiliência e capacidade de expansão. Dessa forma, este trabalho apresenta um estudo de caso em que a análise multicriterial é utilizada para realizar o dimensionamento de uma RDA. Primeiramente, um mapa cognitivo é feito para identificar os principais cri- térios a serem considerados na solução do problema. Em seguida, o método Delphi é usado em conjunto com o Analytic Hierarchy Process (AHP) para determinar os pesos relativos de cada critério. Por fim, três diferentes métodos de análise multicritérios são utilizados para a solução do problema: AHP, Electre e Promethee. Palavras-chave: Rede de distribuição. Otimização. Análise multicritério. Abstract The design of water distribution networks (WDNs) is made to match velocity and pressure constraints that guaran- tee operational efficiency. Thus, pipes with lower cost are selected to attend these conditions. However, this proce- dure can harm other characteristics of the network, as for example its resilience and expansion capacity. Therefore, this paper presents a case study in which the multicriterial analysis is used to design a WDN. First, a cognitive map is built to identify the main criteria to be considered during the design process. Then, the Delphi method is used jointly with the Analytic Hierarchy Process (AHP) to define the relative weights of each criteria. Finally, three different methods for multicriterial analysis are used to solve the problem: AHP, Electre and Promethee. Keywords: Water distribution network. Optimization. Multicriterial analysis.

ACS Style

Bruno Melo Brentan; Gustavo Meirelles Lima; Antonio Carlos Zuffo; Edevar Luvizotto Junior. Dimensionamento de redes de distribuição de água por meio de análise multicriterial. Revista DAE 2019, 221, 118 -130.

AMA Style

Bruno Melo Brentan, Gustavo Meirelles Lima, Antonio Carlos Zuffo, Edevar Luvizotto Junior. Dimensionamento de redes de distribuição de água por meio de análise multicriterial. Revista DAE. 2019; 221 (68):118-130.

Chicago/Turabian Style

Bruno Melo Brentan; Gustavo Meirelles Lima; Antonio Carlos Zuffo; Edevar Luvizotto Junior. 2019. "Dimensionamento de redes de distribuição de água por meio de análise multicriterial." Revista DAE 221, no. 68: 118-130.

Journal article
Published: 01 January 2019 in RBRH
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Integrated management of water supply systems with efficient use of natural resources requires optimization of operational performances. Dividing the water supply networks into small units, so-called district metered areas (DMAs), is a strategy that allows the development of specific operational rules, responsible for improving the network performance. In this context, clustering methods congregate neighboring nodes in groups according to similar features, such as elevation or distance to the water source. Taking into account hydraulic, operational and mathematical criteria to determine the configuration of DMAs, this work presents the k-means model and a hybrid model, that combines a self-organizing map (SOM) with the k-means algorithm, as clustering methods, comparing four mathematical criteria to determine the number of DMAs, namely Silhouette, GAP, Calinski-Harabasz and Davies Bouldin. The influence of three clustering topological criteria is evaluated: the water demand, node elevation and pipe length, in order to determine the optimal number of clusters. Furthermore, to identify the best DMA configuration, the particle swarm optimization (PSO) method was applied to determine the number, cost, pressure setting of Pressure Reducing Valves and location of DMA entrances.

ACS Style

Bernardo Novarini; Bruno Melo Brentan; Gustavo Meirelles; Edevar Luvizotto Junior. Optimal pressure management in water distribution networks through district metered area creation based on machine learning. RBRH 2019, 24, 1 .

AMA Style

Bernardo Novarini, Bruno Melo Brentan, Gustavo Meirelles, Edevar Luvizotto Junior. Optimal pressure management in water distribution networks through district metered area creation based on machine learning. RBRH. 2019; 24 ():1.

Chicago/Turabian Style

Bernardo Novarini; Bruno Melo Brentan; Gustavo Meirelles; Edevar Luvizotto Junior. 2019. "Optimal pressure management in water distribution networks through district metered area creation based on machine learning." RBRH 24, no. : 1.

Journal article
Published: 01 September 2018 in Journal of Water Resources Planning and Management
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New environmental paradigms imposed by climate change and urbanization processes are leading cities to rethink urban management services. Propelled by technological development and the internet of things, an increasingly smart management of cities has favored the emergence of a new research field, namely, the smart city. Within this new way of considering cities, smart water systems are emerging for the planning, operation, and management of water distribution networks (WDNs) with maximum efficiency derived from the application of data analysis and other information technology tools. Considering the possibility of improving WDN operation using available demand data, this work proposes a hybrid and near-real-time optimization algorithm to jointly manage pumps working with variable speed drives and pressure-reducing valves for maximum operational efficiency. A near-real-time demand forecasting model is coupled with an optimization algorithm that updates in real time the water demand of the hydraulic model and can be used to define optimal operations. The D-town WDN is used to validate the proposal. The number of control devices in this WDN makes real time control especially complex. Warm solutions are proposed to cope with this feature as they reduce the computational effort needed if suitably tuned. In addition to energy savings of around 50%, the methodology proposed in this paper enables an efficient system pressure management, leading to significant leakage reduction.

ACS Style

Bruno Brentan; Gustavo Meirelles; Edevar Luvizotto Jr.; Joaquín Izquierdo. Joint Operation of Pressure-Reducing Valves and Pumps for Improving the Efficiency of Water Distribution Systems. Journal of Water Resources Planning and Management 2018, 144, 04018055 .

AMA Style

Bruno Brentan, Gustavo Meirelles, Edevar Luvizotto Jr., Joaquín Izquierdo. Joint Operation of Pressure-Reducing Valves and Pumps for Improving the Efficiency of Water Distribution Systems. Journal of Water Resources Planning and Management. 2018; 144 (9):04018055.

Chicago/Turabian Style

Bruno Brentan; Gustavo Meirelles; Edevar Luvizotto Jr.; Joaquín Izquierdo. 2018. "Joint Operation of Pressure-Reducing Valves and Pumps for Improving the Efficiency of Water Distribution Systems." Journal of Water Resources Planning and Management 144, no. 9: 04018055.

Journal article
Published: 26 May 2018 in Water
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Water distribution networks (WDNs) are designed to meet water demand with minimum implementation costs. However, this approach leads to poor long-term results, since system resilience is also minimal, and this requires the rehabilitation of the network if the network is expanded or the demand increases. In addition, in emergency situations, such as pipe bursts, large areas will suffer water shortage. However, the use of resilience as a criterion for WDN design is a difficult task, since its economic value is subjective. Thus, in this paper, it is proposed that trunk networks (TNs) are rehabilitated when considering the generation of electrical energy using pumps as turbines (PATs) to compensate for an increase of resilience derived from increasing pipe diameters. During normal operation, these micro-hydros will control pressure and produce electricity. When an emergency occurs, a by-pass can be used to increase network pressure. The results that were obtained for two hypothetical networks show that a small increase in TN pipe diameters is sufficient to significantly improve the resilience of the WDN. In addition, the value of the energy produced surpasses the investment that is made during rehabilitation.

ACS Style

Gustavo Meirelles; Bruno Brentan; Joaquín Izquierdo; Helena Ramos; Jr. Edevar Luvizotto. Trunk Network Rehabilitation for Resilience Improvement and Energy Recovery in Water Distribution Networks. Water 2018, 10, 693 .

AMA Style

Gustavo Meirelles, Bruno Brentan, Joaquín Izquierdo, Helena Ramos, Jr. Edevar Luvizotto. Trunk Network Rehabilitation for Resilience Improvement and Energy Recovery in Water Distribution Networks. Water. 2018; 10 (6):693.

Chicago/Turabian Style

Gustavo Meirelles; Bruno Brentan; Joaquín Izquierdo; Helena Ramos; Jr. Edevar Luvizotto. 2018. "Trunk Network Rehabilitation for Resilience Improvement and Energy Recovery in Water Distribution Networks." Water 10, no. 6: 693.

Journal article
Published: 04 May 2018 in Water Supply
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Pressure control is an important feature for reducing leakages in water supply systems, and the use of pressure reducing valves has been well established as an efficient option for this purpose. However, several studies have demonstrated that the energy available on such sites could be used to generate electrical energy, instead of being dissipated as head loss; therefore, a more efficient and sustainable solution could be applied for pressure control. Due to the low amount of power available, the use of pumps as turbines (PATs) is highly recommended. However, manufacturers do not provide pump curves operating as turbines, making PAT selection challenging. Different empirical methods can be found in the literature for estimating PAT performance based on the pump operating conditions. Thus, this paper presents a comparative analysis of nine different methods, using real data from 14 pumps. Furthermore, the effectiveness of these methods for PAT selection is evaluated in a hypothetical network.

ACS Style

Isabela Niedo Marchiori; Gustavo Meirelles Lima; Bruno Melo Brentan; Edevar Luvizotto Junior. Effectiveness of methods for selecting pumps as turbines to operate in water distribution networks. Water Supply 2018, 19, 417 -423.

AMA Style

Isabela Niedo Marchiori, Gustavo Meirelles Lima, Bruno Melo Brentan, Edevar Luvizotto Junior. Effectiveness of methods for selecting pumps as turbines to operate in water distribution networks. Water Supply. 2018; 19 (2):417-423.

Chicago/Turabian Style

Isabela Niedo Marchiori; Gustavo Meirelles Lima; Bruno Melo Brentan; Edevar Luvizotto Junior. 2018. "Effectiveness of methods for selecting pumps as turbines to operate in water distribution networks." Water Supply 19, no. 2: 417-423.

Journal article
Published: 15 January 2018 in Urban Water Journal
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ACS Style

Bruno Melo Brentan; Gustavo Lima Meirelles; Daniel Manzi; Edevar Luvizotto. Water demand time series generation for distribution network modeling and water demand forecasting. Urban Water Journal 2018, 15, 150 -158.

AMA Style

Bruno Melo Brentan, Gustavo Lima Meirelles, Daniel Manzi, Edevar Luvizotto. Water demand time series generation for distribution network modeling and water demand forecasting. Urban Water Journal. 2018; 15 (2):150-158.

Chicago/Turabian Style

Bruno Melo Brentan; Gustavo Lima Meirelles; Daniel Manzi; Edevar Luvizotto. 2018. "Water demand time series generation for distribution network modeling and water demand forecasting." Urban Water Journal 15, no. 2: 150-158.

Technical papers
Published: 01 January 2018 in Journal of Water Resources Planning and Management
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One of the primary concerns in water supply systems is pressure control. High pressure increases both leakage and the risk of pipes bursting, while low pressure can reduce the water supplied to consumers and allow the intrusion of pathogens. Therefore, the operation of the equipment must be optimized to avoid such problems. In high pressure zones, pressure reducing valves (PRVs) are commonly used for pressure control. However, the energy dissipated from head loss could be recovered to produce electrical energy. The use of pumps as turbines (PAT) in this case is an alternative to improve the system efficiency. However, owing to the dynamic operation, PAT performance drops significantly during some periods of the day. The use of variable speeds can solve this problem, but the PAT selection to optimize the operation remains an issue. Therefore, this paper presents a method to simultaneously select PATs and schedule their operation using variable speed to improve energy recovery and reduce leakage. Two networks are studied and the performance in leakage control is compared with the PRV operation.

ACS Style

Gustavo Meirelles Lima; Edevar Luvizotto Jr.; Bruno Melo Brentan; Helena M. Ramos. Leakage Control and Energy Recovery Using Variable Speed Pumps as Turbines. Journal of Water Resources Planning and Management 2018, 144, 04017077 .

AMA Style

Gustavo Meirelles Lima, Edevar Luvizotto Jr., Bruno Melo Brentan, Helena M. Ramos. Leakage Control and Energy Recovery Using Variable Speed Pumps as Turbines. Journal of Water Resources Planning and Management. 2018; 144 (1):04017077.

Chicago/Turabian Style

Gustavo Meirelles Lima; Edevar Luvizotto Jr.; Bruno Melo Brentan; Helena M. Ramos. 2018. "Leakage Control and Energy Recovery Using Variable Speed Pumps as Turbines." Journal of Water Resources Planning and Management 144, no. 1: 04017077.

Research article
Published: 18 December 2017 in Mathematical Problems in Engineering
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Operational and economic aspects of water distribution make water demand forecasting paramount for water distribution systems (WDSs) management. However, water demand introduces high levels of uncertainty in WDS hydraulic models. As a result, there is growing interest in developing accurate methodologies for water demand forecasting. Several mathematical models can serve this purpose. One crucial aspect is the use of suitable predictive variables. The most used predictive variables involve weather and social aspects. To improve the interrelation knowledge between water demand and various predictive variables, this study applies three algorithms, namely, classical Principal Component Analysis (PCA) and machine learning powerful algorithms such as Self-Organizing Maps (SOMs) and Random Forest (RF). We show that these last algorithms help corroborate the results found by PCA, while they are able to unveil hidden features for PCA, due to their ability to cope with nonlinearities. This paper presents a correlation study of three district metered areas (DMAs) from Franca, a Brazilian city, exploring weather and social variables to improve the knowledge of residential demand for water. For the three DMAs, temperature, relative humidity, and hour of the day appear to be the most important predictive variables to build an accurate regression model.

ACS Style

B. M. Brentan; G. Meirelles; M. Herrera; E. Luvizotto; J. Izquierdo. Correlation Analysis of Water Demand and Predictive Variables for Short-Term Forecasting Models. Mathematical Problems in Engineering 2017, 2017, 1 -10.

AMA Style

B. M. Brentan, G. Meirelles, M. Herrera, E. Luvizotto, J. Izquierdo. Correlation Analysis of Water Demand and Predictive Variables for Short-Term Forecasting Models. Mathematical Problems in Engineering. 2017; 2017 ():1-10.

Chicago/Turabian Style

B. M. Brentan; G. Meirelles; M. Herrera; E. Luvizotto; J. Izquierdo. 2017. "Correlation Analysis of Water Demand and Predictive Variables for Short-Term Forecasting Models." Mathematical Problems in Engineering 2017, no. : 1-10.

Article
Published: 05 August 2017 in Water Resources Management
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The success of hydraulic simulation models of water distribution networks is associated with the ability of these models to represent real systems accurately. To achieve this, the calibration phase is essential. Current calibration methods are based on minimizing the error between measured and simulated values of pressure and flow. This minimization is based on a search of parameter values to be calibrated, including pipe roughness, nodal demand, and leakage flow. The resulting hydraulic problem contains several variables. In addition, a limited set of known monitored pressure and flow values creates an indeterminate problem with more variables than equations. Seeking to address the lack of monitored data for the calibration of Water Distribution Networks (WDNs), this paper uses a meta-model based on an Artificial Neural Network (ANN) to estimate pressure on all nodes of a network. The calibration of pipe roughness applies a metaheuristic search method called Particle Swarm Optimization (PSO) to minimize the objective function represented by the difference between simulated and forecasted pressure values. The proposed method is evaluated at steady state and over an extended period for a real District Metering Area (DMA), named Campos do Conde II, and the hypothetical network named C-town, which is used as a benchmark for calibration studies.

ACS Style

Gustavo Meirelles; Daniel Manzi; Bruno Brentan; Thaisa Goulart; Edevar Luvizotto. Calibration Model for Water Distribution Network Using Pressures Estimated by Artificial Neural Networks. Water Resources Management 2017, 31, 4339 -4351.

AMA Style

Gustavo Meirelles, Daniel Manzi, Bruno Brentan, Thaisa Goulart, Edevar Luvizotto. Calibration Model for Water Distribution Network Using Pressures Estimated by Artificial Neural Networks. Water Resources Management. 2017; 31 (13):4339-4351.

Chicago/Turabian Style

Gustavo Meirelles; Daniel Manzi; Bruno Brentan; Thaisa Goulart; Edevar Luvizotto. 2017. "Calibration Model for Water Distribution Network Using Pressures Estimated by Artificial Neural Networks." Water Resources Management 31, no. 13: 4339-4351.

Journal article
Published: 01 August 2017 in Journal of Hydraulic Engineering
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ACS Style

Gustavo Meirelles Lima; Edevar Luvizotto Júnior. Method to Estimate Complete Curves of Hydraulic Pumps through the Polymorphism of Existing Curves. Journal of Hydraulic Engineering 2017, 143, 04017017 .

AMA Style

Gustavo Meirelles Lima, Edevar Luvizotto Júnior. Method to Estimate Complete Curves of Hydraulic Pumps through the Polymorphism of Existing Curves. Journal of Hydraulic Engineering. 2017; 143 (8):04017017.

Chicago/Turabian Style

Gustavo Meirelles Lima; Edevar Luvizotto Júnior. 2017. "Method to Estimate Complete Curves of Hydraulic Pumps through the Polymorphism of Existing Curves." Journal of Hydraulic Engineering 143, no. 8: 04017017.

Research article
Published: 20 February 2017 in Mathematical Problems in Engineering
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Management of large water distribution systems can be improved by dividing their networks into so-called district metered areas (DMAs). However, such divisions must be based on appropriated technical criteria. Considering the importance of deeply understanding the relationship between DMA creation and these criteria, this work proposes a performance analysis of DMA generation that takes into account such indicators as resilience index, demand similarity, pressure uniformity, water age (and thus water quality), solution implantation costs, and electrical consumption. To cope with the complexity of the problem, suitable mathematical techniques are proposed in this paper. We use a social community detection technique to define the sectors, and then a multilevel particle swarm optimization approach is applied to find the optimal placement and operating point of the necessary devices. The results obtained by implementing the methodology in a real water supply network show its validity and the meaningful influence on the final result of, especially, elevation and pipe length.1. IntroductionThe frequent disorderly spatial expansion of cities, mainly in developing countries, compels water utilities to rethink their management practice, aiming at highly efficient systems. Optimal management of water distribution systems (WDSs) requires accurate decisions to reduce the waste of environmental resources and to supply consumers with high quality water. Usually, these decisions are made under uncertainty scenarios, mainly due to the size of the network. The segregation of large networks into nearly independent water supply zones can reduce the uncertainty of the problem, thus allowing smarter operation to get better service conditions [1, 2].District metered area (DMA) design was introduced in the UK [3] and has been widely applied to pressure management and leakage control [4–8]. Also, the identification of entrance pipes and consequent measurement of inlet flow allow improving the water balance, helping to identify leakage and nonrevenue water. However, network segmentation can be a hard task due to various network characteristics: size, number of loops, topology changes, and necessary modifications of the hydraulic conditions during operation. DMA creation requires not only a perfect knowledge of the topological information of the network, but also a set of criteria able to generate a consistent network partition. Depending on the criteria adopted and the combination of them, different topologies can be found that can improve (or worsen!) the efficiency of the network.The use of trial and error methodologies, which do not consider global perspectives of WDSs, can result in nonoptimal solutions, thus reducing the possibilities of performance improvement through DMA creation. Various developments of automatic tools to help the process of water network partition have been proposed. Among others, [9] presents a graph theory approach to water distribution network decomposition; [10] applies a method based on machine learning for DMA design; [11] proposes the use of a multiagent based approach to negotiate boundaries in DMA generation; [12] develops an automatic boundary generation to determine DMAs based on a social structure, a tool from the artificial intelligence field; and [13] presents an insightful comparison among global clustering, community structure, and graph partition methodologies applied to two big cities; in this last case, the authors argue positively about the high performance of community structures for DMA design from the computational and clustering viewpoints; however, hydraulic and quality analyses are left out.Graph clustering and, more specifically, the use of an unknown number of subdivisions, as in the proposal based on social network theory [14] have proven to be a good approach for the sectorization problem. Physical and hydraulic features such as the lowest distance to water source, node elevation, and cumulated demand are easily used as criteria to divide the distribution network. However, considering the approach that the a priori number of DMAs is not generally defined, the performance of each scenario is affected by the DMA design criteria used, which enables the generation of very diverse partitions.While the former approaches on DMA design had pressure management and leakage control as the main objectives, nowadays multiple criteria have been adopted to generate resilient and high-performance networks in terms of hydroenergetic issues, as observed in [15], where the authors present a graph-theoretical approach for the resilience assessment of large scale WDSs.More than grouping the nodes inside their respective DMAs, a complete sectorization process must include the selection of an optimal entry choice, that is to say, an optimal Control Unit (CU) placement, with at least one flowmeter to permanently monitor the inlet flow [14]. If necessary, pressure reducing valves (PRVs) may also be installed at the entries (also in other points) of the DMAs for pressure regulation purposes. The maximization of a reliability indicator [6] and the minimization of costs are the most common approaches to find the optimal PRV placement. Also, [16] develops an approach for optimal DMA definition considering the possibility of generating energy by using turbines; graph theory and clustering techniques are used, jointly with Simulated Annealing, to identify the optimal entry and pipe replacement.Furthermore, water distribution network segmentation implies the closure of some pipes. The consequent reduction of loops in the network can affect directly the reliability of the network [6]. In this way, a suitable balanced scenario among the benefits associated with DMA creation should be considered (or developed), where costs, reliability, and efficiency are jointly taken into account. The evaluation of DMA scenarios can be an important design tool and can help the decision-maker to choose an optimal, hopefully the best, option of DMA configuration.Reference [17] presents a set of feasible solutions of DMA design and evaluates the solution in terms of the resilience index [18], the number of closed pipes, and the water age. The authors conclude that sectorization can produce a small decrease of some performance indicators, but it is insignificant when compared with the benefits of DMA implementation.Taking into account the variability of feasible solutions for different nodal aggregation criteria for the problem of DMA design, social network community detection algorithms, grounded in graph theory, are used in this paper to define a set of scenarios of DMA configurations. This approach allows evaluating the effect of DMA creation considering the total or partial isolation of the network and even considering the presence of cascading DMAs. To evaluate the performance of a DMA configuration, various values for the criteria are applied. In a second-level, particle swarm optimization (PSO) is applied to determine the optimal placement and operating points of PRVs by considering all the boundary pipes as possible candidates to become DMAs’ entrances. The results are evaluated in terms of resilience index, pressure uniformity, demand similarity, water age, electrical consumption, and implementation costs.2. Materials and Methods2.1. DMA Definition by a Community Detection AlgorithmVirtual social networks can be described as specialized graphs aimed at describing the interaction of elements that form part of a society, holding some degree of interdependence among them. In this context, an individual is an entity that generates a contribution to the society (network). One of the aspects of major interest in social network science corresponds to community detection, which allows understanding the organization and function of individuals in the network. Unlike traditional clustering in graphs, community detection is not solely focused on individuals, or nodes (and their features). It also takes into account the connection between them, so that the resulting communities are formed not only by individuals, but also by their interactions. One of the most widely known community detection algorithms is the Walktrap algorithm, proposed by Pons and Latapy [19]. This algorithm is based on random walks over graphs.In the field of mathematics and probability theory, random walks (or diffusion processes) are defined as stochastic processes in which the position of a particle (walker) in a given instant depends on its previous position and a random variable that determines the direction taken from that previous position towards one of the neighboring nodes. Random paths in a (globally sparse but locally dense) graph tend to get trapped into densely connected parts, which correspond to communities [19]. A random walk in such a graph is a Markov chain that can be described by the information contained in the so-called transition matrix, . Element of , giving the transition probability from vertex to vertex , is calculated as the ratio , where is the () element of the adjacency matrix, , of the graph, and is the degree of vertex , that is to say, the number of its neighbors including itself. The th power of this matrix, , with elements noted as , gives the probabilities of moving from one node to another node through a path of length . As shown in [19], these probabilities are enough to gather information on the topology of the network.In this algorithm, distances between nodes and communities (see (1) and (2), resp.) based on matrix are computed bywhere and are two given nodes, is the degree of node , and is the total number of nodes of the network. Equation (2) is actually a generalization of (1) to compute the distance between communities ( represent two different communities). For this last calculation, random walks go between randomly chosen nodes in both communities. Note that, in particular, any of those communities may be reduced to

ACS Style

Bruno M. Brentan; Enrique Campbell; Gustavo L. Meirelles; Edevar Luvizotto; Joaquín Izquierdo; Joaqu&#xed Izquierdo. Social Network Community Detection for DMA Creation: Criteria Analysis through Multilevel Optimization. Mathematical Problems in Engineering 2017, 2017, 1 -12.

AMA Style

Bruno M. Brentan, Enrique Campbell, Gustavo L. Meirelles, Edevar Luvizotto, Joaquín Izquierdo, Joaqu&#xed Izquierdo. Social Network Community Detection for DMA Creation: Criteria Analysis through Multilevel Optimization. Mathematical Problems in Engineering. 2017; 2017 ():1-12.

Chicago/Turabian Style

Bruno M. Brentan; Enrique Campbell; Gustavo L. Meirelles; Edevar Luvizotto; Joaquín Izquierdo; Joaqu&#xed Izquierdo. 2017. "Social Network Community Detection for DMA Creation: Criteria Analysis through Multilevel Optimization." Mathematical Problems in Engineering 2017, no. : 1-12.

Journal article
Published: 13 June 2015 in Water Supply
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The Brazilian Labeling Program is a forceful instrument for the conservation of energy. In addition to allowing consumers to evaluate the best products from an energy point of view, it sets targets to make the products increasingly more efficient. In this context, buildings that can currently obtain the energy efficiency label are also included, demonstrating to customers the concern for sustainability. However, there are still many products and systems that can be labeled but for which legislation has not yet been enacted, including water supply systems. Owing to the different characteristics of the systems and the different possibilities for efficiency improvement, it is necessary to develop indicators that actually represent the reality of each system and make it possible to compare them. Thus, this study proposes the use of certain indicators for classification of the systems. A classification by sector benchmarking is also proposed in Brazil, and an example is presented for the classification of Brazilian systems based on four indicators obtained by the National Sanitation Information System.

ACS Style

Gustavo Meirelles Lima; Augusto Nelson Carvalho Viana; Renato Swerts Carneiro Dias Junior; Edevar Luvizotto Junior. Classification of water supply systems based on energy efficiency. Water Supply 2015, 15, 1193 -1199.

AMA Style

Gustavo Meirelles Lima, Augusto Nelson Carvalho Viana, Renato Swerts Carneiro Dias Junior, Edevar Luvizotto Junior. Classification of water supply systems based on energy efficiency. Water Supply. 2015; 15 (6):1193-1199.

Chicago/Turabian Style

Gustavo Meirelles Lima; Augusto Nelson Carvalho Viana; Renato Swerts Carneiro Dias Junior; Edevar Luvizotto Junior. 2015. "Classification of water supply systems based on energy efficiency." Water Supply 15, no. 6: 1193-1199.

Journal article
Published: 01 December 2011 in Journal of the Brazilian Society of Mechanical Sciences and Engineering
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An accurate knowledge of thermophysical properties is very important, for example, to optimize the engineering design and the development of new materials for many applications. Thermal effusivity is a thermal property which presents an increasing importance in heat conduction problems. This property indicates the amount of thermal energy that a material is able to absorb. The estimation can be done by simulating a transient heat transfer model. In this case a one-dimensional semi-infinite thermal model is used. A resistance heater in contact with the sample generates a heat pulse. Variations of temperature and heat flux are measured simultaneously on the top surface of the sample. In this work, thermal effusivity is estimated in time domain through the minimization of the objective function, defined as the square difference between experimental and theoretical temperatures. The golden section technique is used for minimizing this objective function. A sensitivity analysis and a comparison between the semi-infinite and the finite models were also done to define the number of points to be used in the estimation. Measurements were carried out with three different polymers: polymethyl methacrylate, polyvinyl chloride and polyethylene. In all cases studied the results are in good agreement with literature. In addition, an uncertainty analysis is also presented

ACS Style

Gustavo Meirelles Lima; Sandro M. M. De Lima E Silva. Thermal effusivity estimation of polymers in time domain. Journal of the Brazilian Society of Mechanical Sciences and Engineering 2011, 33, 393 -399.

AMA Style

Gustavo Meirelles Lima, Sandro M. M. De Lima E Silva. Thermal effusivity estimation of polymers in time domain. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2011; 33 (4):393-399.

Chicago/Turabian Style

Gustavo Meirelles Lima; Sandro M. M. De Lima E Silva. 2011. "Thermal effusivity estimation of polymers in time domain." Journal of the Brazilian Society of Mechanical Sciences and Engineering 33, no. 4: 393-399.