Filters








9,706 Hits in 6.9 sec

On the Flow Problem in Water Distribution Networks: Uniqueness and Solvers [article]

Manish K. Singh, Vassilis Kekatos
2020 arXiv   pre-print
Given the water injection or pressure at each WDS node, finding the water flows within pipes and pumps along with the pressures at all WDS nodes constitutes the water flow (WF) problem.  ...  Increasing concerns on the security and quality of water distribution systems (WDS), call for computational tools with performance guarantees.  ...  water distribution networks.  ... 
arXiv:1901.03676v2 fatcat:muhidcdhsbbp3pdsqx54hpwjyq

Natural Gas Flow Equations: Uniqueness and an MI-SOCP Solver [article]

Manish K. Singh, Vassilis Kekatos
2018 arXiv   pre-print
Unlike existing alternatives, the devised solver does not need proper initialization or knowing the gas flow directions beforehand, and can handle gas networks with compressors.  ...  and pressures in GNs.  ...  The cost r(ψ) sums up the absolute pressure differences across all lossy pipes. A similar MI-SOCP relaxation has been proposed for optimizing flow in water distribution networks in [12] .  ... 
arXiv:1809.09025v1 fatcat:mgpolpnqcnbuvgvcisb2bdzudm

Constraint Applications in Networks [chapter]

Helmut Simonis
2006 Foundations of Artificial Intelligence  
Network problems arise in many different domains, we take a rather narrow view in this presentation and concentrate on three areas: electrical networks water (oil) networks data networks Some of the earliest  ...  One of the most interesting practical problems in this domain is the configuration of electrical power distribution networks (section 1), which has been studied with different constraint techniques and  ...  Water networks differ from electrical networks in a number of fundamental ways: -Water can be stored in the network, reservoirs and water towers are key elements of water distribution systems.  ... 
doi:10.1016/s1574-6526(06)80029-5 fatcat:ipmughz6kbezfgbe7lzu3eafpm

Mathematical programming techniques in water network optimization

Claudia D'Ambrosio, Andrea Lodi, Sven Wiese, Cristiana Bragalli
2015 European Journal of Operational Research  
The basic underlying model in both cases is a nonlinear network flow model, and we give an overview on the more specific modeling aspects in each case.  ...  Finally, we survey the algorithmic approaches to solve the proposed problems and we discuss computation on various types of water networks.  ...  We also thank Wei Huang, Lars Schewe and Antonio Morsi for their helpful comments in the context of water network operation.  ... 
doi:10.1016/j.ejor.2014.12.039 fatcat:bnz2xndmdrayjfyvomcp2dg7hi

Analysis and control on networks: Trends and perspectives

Fabio Ancona, Laura Caravenna, Annalisa Cesaroni, Giuseppe Maria Coclite, Claudio Marchi, Andrea Marson
2017 Networks and Heterogeneous Media  
Because of the finite speed of propagation, once a Riemann Solver at a junction is prescribed, the Cauchy problem on a network can be uniquely solved under suitable assumptions.  ...  In the last twentyfive years, there has been a dramatic increase of the number of works devoted to the analysis of flows dynamics on networks based on hyperbolic partial differential equations (PDEs),  ... 
doi:10.3934/nhm.201702i fatcat:cjgnhpqverexjne2zzwsjyc7py

A Network Simplex Algorithm for the Equal Flow Problem on a Generalized Network

David R. Morrison, Jason J. Sauppe, Sheldon H. Jacobson
2013 INFORMS journal on computing  
A network simplex algorithm is described for the minimum-cost network flow problem on a generalized network with the additional constraint that there exist sets of arcs which must carry equal amounts of  ...  Then it must be the case that the flow function for this basis is not unique.  ...  Others include water distribution and management over leaky pipes, currency exchange networks (where the multipliers on the arcs represent the amount of money gained or lost when trading from one currency  ... 
doi:10.1287/ijoc.1110.0485 fatcat:xpgfvlpz65bifpj5u4je2v4riu

Improved Pressurized Pipe Network Hydraulic Solver for Applications in Irrigation Systems

Carlos Estrada, César González, Ricardo Aliod, Jara Paño
2009 Journal of irrigation and drainage engineering  
The hydraulic solver for quasi-steady scenarios uses specific strategies and incorporates several new features that improve the algorithms for pipe network computation, overcoming some of the problems  ...  In this contribution the results of the research on computational strategies capable of dealing with low resistance elements, hydrant modelling, multiple regulation valves, numerous emitters, and pumps  ...  This allows it to overcome some limitations and problems found in other computational tools like EPANET, the reference code for hydraulic and water quality simulation in drinking water networks ͑Rossman  ... 
doi:10.1061/(asce)ir.1943-4774.0000100 fatcat:ktvk3gezrrcijo6iiqtaudplya

River Network Routing on the NHDPlus Dataset

Cédric H. David, David R. Maidment, Guo-Yue Niu, Zong-Liang Yang, Florence Habets, Victor Eijkhout
2011 Journal of Hydrometeorology  
21 The mapped rivers and streams of the contiguous United States are available in a 22  ...  The river network of 649 the Upper Mississippi River Basin is fully interconnected, all water eventually flowing to 650 a unique outlet. 651 In order to assess the performance of RAPID, the same problem  ...  The two iterations and calculations of norms explain the doubling of 713 computing time between preconditioning only and an iterative solver on one unique 714 processing core that is shown in Figure 11  ... 
doi:10.1175/2011jhm1345.1 fatcat:4igescy3mrgtbf6btmfnv4lyoe

Constraint-Preconditioned Inexact Newton Method for Hydraulic Simulation of Large-Scale Water Distribution Networks

Edo Abraham, Ivan Stoianov
2017 IEEE Transactions on Control of Network Systems  
Many sequential mathematical optimization methods and simulation-based heuristics for optimal control and design of water distribution networks rely on a large number of hydraulic simulations.  ...  In this paper, we propose an efficient inexact subspace Newton method for hydraulic analysis of water distribution networks.  ...  valves and pumps), the hydraulic analysis problem involves the computations of flows in pipes and pressures at the nodes.  ... 
doi:10.1109/tcns.2016.2548418 fatcat:u6whb3naund4rcklgwguecwn6m

Towards Real-Time Monitoring and Control of Water Networks [article]

Ahmed Elkhashap, Daniel Rüschen, Dirk Abel
2022 arXiv   pre-print
Water networks are used in numerous applications, all of which have the essential task of real-time monitoring and control of water states.  ...  The network model is able to predict the temperature evolution, flow rate, and pressure accurately at the different paths of the network with mean relative errors below 4 \%, 2 \%, and 2 \%, respectively  ...  The knowledge of at the least one head (pressure) at any node in the network is a requirement for the existence of a unique solution for the network flow problem  ... 
arXiv:2201.04654v2 fatcat:n4tjsvf5enfyjlsnu5hm2d6pbq

Failure monitoring in water distribution networks

D. Misiunas, J. Vítkovský, G. Olsson, M. Lambert, A. Simpson
2006 Water Science and Technology  
An algorithm for the burst detection and location in water distribution networks based on the continuous monitoring of the flow rate at the entry point of the network and the pressure at a number of points  ...  The EPANET steady-state hydraulic solver is utilised to simulate the flows and pressures in the network.  ...  One flow rate and only three pressure monitoring points are enough to find the unique location of the burst that occurs at (or in between) for up to 70% of nodes in the network that has 79 nodes and 108  ... 
doi:10.2166/wst.2006.154 pmid:16722103 fatcat:tptdsue3d5g5dpd3u7ctex22cq

Solving Sensor Placement Problems In Real Water Distribution Networks Using Adiabatic Quantum Computation [article]

Stefano Speziali, Federico Bianchi, Andrea Marini, Lorenzo Menculini, Massimiliano Proietti, Loris F. Termite, Alberto Garinei, Marcello Marconi, Andrea Delogu
2021 arXiv   pre-print
In this paper, we formulate the problem of correctly placing pressure sensors on a Water Distribution Network (WDN) as a combinatorial optimization problem in the form of a Quadratic Unconstrained Binary  ...  We then apply our methods to the case of a real Water Distribution Network. Both simulated annealing and a hybrid quantum-classical approach on a D-Wave machine are employed.  ...  In this paper, we formulate the problem of correctly placing pressure sensors on a Water Distribution Network (WDN) as a combinatorial optimization problem in the form of a Quadratic Unconstrained Binary  ... 
arXiv:2108.04075v2 fatcat:gdj52i4hxbakpcgvrztevf7rfy

Incorporating the Modified Orifice Equation into Pipe Network Solvers for More Realistic Leakage Modeling

A. M. Kabaasha, O. Piller, J. E. van Zyl
2018 Journal of Hydraulic Engineering  
The conventional and modified software were applied to 600 instances of stochastic leakage distributions in three different pipe networks.  ...  The purpose of this study was to incorporate the modified orifice equation into the hydraulic network formulation and evaluate its impact on model performance.  ...  Simon Scruton and his team at the eThekwini Water and Sanitation unit, for providing water distribution network model of the central business district of Durban, from which the large network was adapted  ... 
doi:10.1061/(asce)hy.1943-7900.0001410 fatcat:o2ntcfdqv5fr5c6glv47lkxioq

Flows on networks: recent results and perspectives

Alberto Bressan, Sunčica Čanić, Mauro Garavello, Michael Herty, Benedetto Piccoli
2014 EMS Surveys in Mathematical Sciences  
In particular, a number of results, mainly dealing with vehicular traffic, supply chains and data networks, were collected in two monographs: Traffic flow on networks, AIMSciences, Springfield, 2006, and  ...  The broad research thematic of flows on networks was addressed in recent years by many researchers, in the area of applied mathematics, with new models based on partial differential equations.  ...  Many existing papers regarding traffic flow on a road network use a (Markov) distribution matrix to distribute traffic flow at intersections [71] , [88] , [101] , [41] .  ... 
doi:10.4171/emss/2 fatcat:oixiq57eiracvekwoz6vg4xevm

Minimum cost network flows: Problems, algorithms, and software

Angelo Sifaleras
2013 Yugoslav Journal of Operations Research  
We present a wide range of problems concerning minimum cost network flows, and give an overview of the classic linear single-commodity Minimum Cost Network Flow Problem (MCNFP) and some other closely related  ...  We also discuss state-of-the-art algorithmic approaches and recent advances in the solution methods for the MCNFP. Finally, optimization software packages for the MCNFP are presented.  ...  ACKNOWLEDGMENTS This research has been partly funded by the Research Committee of the University of Macedonia, Economic and Social Sciences, Greece, under grant 80749 for the advance of Basic Research.  ... 
doi:10.2298/yjor121120001s fatcat:teynps3rx5cmhhkljjuyt5e6v4
« Previous Showing results 1 — 15 out of 9,706 results