• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 13
  • 7
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 44
  • 25
  • 15
  • 13
  • 11
  • 10
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 7
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Comparison and Simulation of a Water Distribution Network in EPANET and a New Generic Graph Trace Analysis Based Model

Newbold, James Richard 17 February 2009 (has links)
The main purpose of this study was to compare the Distributed Engineering Workstation (DEW) and EPANET models. These two models are fundamentally different in the approaches taken to simulate hydraulic systems. To better understand the calculations behind each models' hydraulic simulation, three solution methods were evaluated and compared. The three solution approaches were the Todini, Hardy-Cross, and DEW bisection methods. The Todini method was included in the study because of its similarities to EPANET's hydraulic solution method and the Hardy-Cross solution was included due to its similarities with the DEW approach. Each solution method was used to solve a simple looped network, and the hydraulic solutions were compared. It was determined that all three solution methods predicted flow values that were very similar. A different, more complex looped network from the solution method comparison was simulated using both EPANET and DEW. Since EPANET is a well established water distribution system model, it was considered the standard for the comparison with DEW. The predicted values from the simulation in EPANET and DEW were compared. This comparison offered insight into the functionality of DEW's hydraulic simulation component. The comparison determined that the DEW model is sensitive to the tolerance value chosen for a simulation. The flow predictions between the DEW and EPANET models became much closer when the tolerance value in DEW was decreased. / Master of Science
2

Gestão de perdas em redes de abastecimento de água - assistida pelo simulador EPANET

Moreira, Tiago Orlando Morais January 2011 (has links)
Tese de mestrado integrado. Engenharia do Ambiente. Faculdade de Engenharia. Universidade do Porto. 2011
3

Modelação e calibração de um sistema de abastecimento de água

Pinto, Tiago Manuel Vieira January 2010 (has links)
Tese de mestrado integrado. Engenharia do Ambiente. Faculdade de Engenharia. Universidade do Porto. 2010
4

Προγραμματισμός αντλιών δικτύου ύδρευσης μέσω προσομοίωσης της λειτουργίας του υδραυλικού του μοντέλου με το λογισμικό EPANET

Στούμπος, Ιωάννης 16 January 2012 (has links)
Το βασικό θέμα της διπλωματικής εργασίας είναι η χρήση μεταευρετικών τεχνικών για την επίλυση ενός συνδυαστικού προβλήματος βελτιστοποίησης. Πιο συγκεκριμένα, ένας μεταευρετικός αλγόριθμος προσομοιωμένης ανόπτησης δημιουργήθηκε προκειμένου να αποκτηθεί το ελάχιστο κόστος λειτουργίας ενός κυκλικού δικτύου διανομής νερού. Η προσομοιωμένη ανόπτηση είναι μία στοχαστική μέθοδος βελτιστοποίησης που μπορεί να ανταποκριθεί καλά σε μεγάλης κλίμακας προβλήματα βελτιστοποίησης διακριτής ή συνδυαστικής μορφής, αλλά στο πρόβλημα που επιλύθηκε Αρχικά παρουσιάζονται τα χαρακτηριστικά και τα επιμέρους στοιχεία των δικτύων διανομής νερού μαζί με τους νόμους της φυσικής που τα διέπουν. Ειδικότερη προσοχή δίνεται στο πιο ακριβό στοιχείο, την αντλία. Στη συνέχεια παρουσιάζεται το EPANET, ένα πακέτο λογισμικού για τη μοντελοποίηση δικτύων ύδρευσης, μαζί με το programmers toolkit που θα επιτρέψει την αλληλεπίδραση μεταξύ Java και του λογισμικού μοντελοποίησης του δικτύου. Στο 6ο κεφάλαιο μία εφαρμογή προτείνεται, ο στόχος της οποίας είναι η ελαχιστοποίηση του κόστους και της κατανάλωσης της ηλεκτρικής ενέργειας. Η εφαρμογή μετά δοκιμάζεται στο πρόβλημα Van Zyl, ένα δίκτυο διανομής νερού μικρής κλίμακας που είναι κατάλληλο για δοκιμές εξαιτίας του γεγονότος ότι πολλές διαμορφώσεις προγράμματος λειτουργίας αντλιών είναι έγκυρες, παρέχοντας έτσι μία μεγάλη ποικιλία προγραμμάτων λειτουργίας. Η μέθοδος της προσομοιωμένης ανόπτησης παρουσιάζεται στη συνέχεια σταδιακά και τα αποτελέσματα απεικονίζονται με τη βοήθεια πινάκων και σχεδιαγραμμάτων. Το τελευταίο κεφάλαιο συζητά γενικά συμπεράσματα που αφορούν νέα πεδία προς αναζήτηση τα οποία θα μπορούσαν να βελτιώσουν τις μεθόδους βελτιστοποίησης των προβλημάτων χρονοπρογραμματισμού αντλιών δικτύων ύδρευσης / The main topic of this diploma thesis is the use of metaheuristics for solving a combinatorial optimization problem. In particular, a simulated annealing metaheuristic was developed to obtain the least cost operation of a looped water distribution network. Simulated annealing is a stochastic optimization method that can work well for large-scale optimization problems that are cast in discrete or combinatorial form, and with the problem solved. First of all water distribution systems’ characteristics and components are stated along with the laws of physics that govern them. Particular attention is given to the most expensive component of all, the pump. Then, EPANET, a public domain, water distribution system modeling software package is presented along with the programmers’ toolkit that will enable the interaction between Java and the network modeling software. In Chapter 6, one application is proposed, whose goal is to minimize electricity cost and consumption. The application will then be tested on the Van Zyl Test Problem, a water distribution system of small scale that is well suited for testing due to the fact that many pump configurations are valid, providing a vast range of configurations. The method of simulated annealing is then presented gradually, and the results will be depicted with the help of plots and tables. The final chapter also discusses general conclusions concerning new fields for research that could improve the optimization techniques for pump scheduling problems.
5

Proposição de calibração de redes de sistemas de abastecimento de água através de método híbrido / A proposition for calibrating water distribution systems models using hybrid method

Abe, Narumi 30 May 2014 (has links)
A popularização das tecnologias de monitoramento remoto possibilita e cria a necessidade do desenvolvimento de sistemas de calibração mais velozes, capazes de calibrar redes enquanto recebem dados, ou seja, em em tempo real. Este trabalho consistiu na proposição de dois novos métodos de calibração baseados em redes neurais artificiais construtivas, visando a aumentar a velocidade de processamento e a performance dos sistemas de calibração. O primeiro método consistiu em calibrar utilizando somente redes neurais artificiais. Um sistema foi desenvolvido para recorrentemente produzir respostas de modelos hidráulicos baseados no Epanet e transformá-los em padrões de treinamento para as RNA (redes neurais artificiais) construtivas. O segundo método consistiu no desenvolvimento de um sistema de calibração híbrido, utilizando as saídas da RNA do primeiro método para produzir valores para constituir a população inicial de soluções a serem buscadas usando os algoritmos genéticos (AG). Assim, pode-se considerar que o método híbrido proposto foi desenvolvido para produzir soluções a partir de boas aproximações para os valores ótimos. Os métodos propostos foram aplicados a quatro (4) setores de rede da cidade de Araraquara, SP. Os resultados das calibrações foram avaliados através da comparação das simulações e com os respectivos valores observados em campo, considerando critérios recomendados no Reino Unido. O primeiro método proposto mostrou-se pouco eficiente no processo de calibração, sendo útil, entretanto, como a primeira etapa da calibração através do método híbrido. O segundo método superou ligeiramente a performance obtida na qualidade da calibração dos dados de cargas de pressões e vazões comparadas com métodos de calibração clássicos e foi bastante superior no quesito velocidade. / The popularization of remote monitoring technologies allows and creates the need to develop faster calibration systems capable of calibrating networks while receiving data, i.e., in real time. This work consisted in proposing two new calibration methods based on constructive neural networks, aiming to increase the processing speed and performance of calibration systems. The first method was to calibrate using only artificial neural networks. A system was developed to produce responses of hydraulic models based on Epanet and turn them into training patterns for the constructive ANN (artificial neural networks) recurrently. The second method consisted in developing a hybrid calibration system using the outputs of the first method of RNA to produce values for the initial population of solutions to be searched using the genetic algorithms (GA). Thus, it can be considered that the hybrid method was developed to produce solutions from good approximations for the optimal values. The proposed methods were applied to four sectors of the city of Araraquara , SP. The results of the calibrations were evaluated by comparing the simulations and the respective values observed in the field, considering criteria recommended in the UK. The first proposed method proved inefficient in the calibration process, it is useful, however, as the first step of the calibration using the hybrid method. The second method was slightly better in performance obtained in the quality of the calibration data of pressures and flow rates compared with classical methods of calibration and it was quite superior in speed.
6

Desenvolvimento de uma Interface em SIG para Suporte ao Dimensionamento HidrÃulico de Sistemas de Abastecimento de Ãgua / DEVELOPMENT OF AN INTERFACE IN SIG FOR SUPPORT TO THE HYDRAULICAL SIZING OF SYSTEMS OF WATER SUPPLY

Eulimar Cunha TibÃrcio 11 September 2006 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Os estudos realizados na Ãrea de Recursos HÃdricos sÃo geralmente modelos que precisam de dados fÃsicos e topogrÃficos que tradicionalmente sÃo obtidos nos mapas ou com pesquisas de campo. Recentemente, estas informaÃÃes estÃo sendo agregadas diretamente em Sistema de InformaÃÃo GeogrÃfica (SIG) devido aos avanÃos tecnolÃgicos desenvolvidos por estes sistemas e Ãs contÃnuas melhorias em modelo digital de terreno. Atualmente, esforÃos tÃm sido realizados para desenvolver interfaces em SIG que dÃem suporte ao trabalho de projetistas de sistemas de abastecimento de Ãgua e, tambÃm, constata-se a existÃncia de trabalhos com modelos hidrÃulicos aliados a SIG. Tendo em vista os avanÃos em tecnologia de software de SIG, esta pesquisa pretende mostrar a viabilidade do uso de Sistema de InformaÃÃo GeogrÃfica aplicado ao dimensionamento hidrÃulico de sistemas de abastecimento de Ãgua sob pressÃo atravÃs do desenvolvimento e aplicaÃÃo de uma interface incorporada a um SIG reconhecido internacionalmente pela comunidade cientÃfica que trabalha com dados espaciais (ArcMap) que utiliza rotinas do simulador hidrÃulico EPANET, permitindo, assim, a comunicaÃÃo entre estas duas tecnologias. Esta interface tem como importÃncia o fato de ter sido construÃda com ArcObjects (mesma plataforma de desenvolvimento da famÃlia de aplicativos ArcGIS Desktop do Environmental Systems Research Institute â ESRI); tem como caracterÃstica uma fÃcil interaÃÃo para digitalizar componentes hidrÃulicos por coordenadas, permitindo, assim, uma aproximaÃÃo de um modelo em anÃlise de uma situaÃÃo real, dimensionar componentes do sistema, fornecer informaÃÃo relacionada à operaÃÃo do sistema, selecionar opÃÃes de simulaÃÃo hidrÃulica, carregar o layout do sistema na Ãrea de trabalho do EPANET, visualizar a descriÃÃo-base do sistema, mostrar o relatÃrio da Ãltima simulaÃÃo, alterar duraÃÃo da simulaÃÃo, alterar diÃmetros de tubulaÃÃo, desfazer ediÃÃo de diÃmetros, gerar novo relatÃrio, visualizar os dados hidrÃulicos dos componentes apÃs cada simulaÃÃo, alterar componentes hidrÃulicos, mover componentes para coordenadas apropriadas, entre outros; tem como objetivo facilitar as atividades do projetista de sistema de distribuiÃÃo de Ãgua, dando, portanto, continuidade ao estudo de modelos hidrÃulicos aliados a ferramentas de geoprocessamento; tem, enfim, a possibilidade de ser continuamente melhorada para atender Ãs novas exigÃncias do projetista de redes de abastecimento de Ãgua. / The studies in water resources are models that need data gotten in the maps or research of field. Recently, these information are being added directly in Geographic Information System (GIS) due to the technological advances developed by these systems and to the continuous improvements in digital land model. Currently, efforts have been carried through to develop interfaces in GIS that give support to the work of designers of systems of water supply and, also, evidence it existence of works with hydraulical models allies the GIS. In view of the advances in technology of GIS software, this research it intends to show the viability of the use of GIS applied to the hydraulical sizing of systems of water supply under pressure through the development and application of a connected interface to the ArcMap that uses routines of hydraulical simulator EPANET, allowing, thus, the communication between these two technologies. This interface has as importance the fact to have been constructed with ArcObjects (same platform of development of the family of applications ArcGIS Desktop of the Environmental Systems Research Institute - ESRI); it has as characteristic an easy interaction to sketch hydraulical components through coordinates, allowing, thus, an approach of a model in analysis of a real situation, sizing of components of the system, to supply related information to the operation of the system, to select options of hydraulical simulation, to load the layout of the system in the area of work of the EPANET, to visualize the description-base of the system, to show the report of the last simulation, to visualize hydraulical data of the components each simulation, to modify hydraulical components, to move components for appropriate coordinates, among others; it has as objective to facilitate the activities of the designer of system of water distribution, giving, therefore, continuity to the study of hydraulical models allies the Geo-processing tools; it has, at last, the possibility of continuously being improved to take care of to the new requirements of the designer of nets of water supply.
7

Uma Ferramenta Computacional para AuxÃlio em Projetos de Sistemas de Abastecimento de Ãgua / A Computational Tool to Aid Projects in Water Supply Systems

Renata Shirley de Andrade Valdivino 21 September 2011 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Redes de abastecimento de Ãgua sÃo ferramentas importantes para garantir a saÃde e o bem-estar social, entretanto, elaborar projetos para desenvolver essas estruturas implica em atividades com etapas muito onerosas e repetitivas. Assim, com o objetivo de reduzir o tempo gasto, garantindo a qualidade e eficiÃncia do projeto final, os programas computacionais vÃm ganhando espaÃo e importÃncia em projetos de engenharia. O programa UFC3 à um aplicativo desenvolvido nas linguagens AutoLISP, VBA (Visual Basic of Applications) e VB (Visual Basic), o qual possui recursos grÃficos para auxiliar no desenvolvimento de projetos dentro do ambiente AutoCAD. Este trabalho foi desenvolvido para auxiliar no traÃado de redes de abastecimento, possibilitando a inserÃÃo de conexÃes, bem como, as informaÃÃes caracterÃsticas de cada nà (pressÃo, cota e carga hidrÃulica), calcular os quantitativos de rede, para gerar uma planilha apresentando os resultados para trechos e nÃs a partir da simulaÃÃo realizada por meio do software EPANET. AlÃm disso, o programa constrÃi o desenho do perfil longitudinal de adutoras, incluindo as linhas piezomÃtricas e de carga mÃxima e mÃnima. O programa UFC3 permite que sejam inseridos os seguintes acessÃrios: cruzeta, te, curva (22.5Â, 45Â, 90Â), luva, junÃÃo, reduÃÃo, adaptador, cap, cruzeta de reduÃÃo, te de reduÃÃo e registro. De modo geral, elas sÃo inseridas automaticamente pelo programa, exceto pelo cap. As planilhas de resultados e de quantitativos gerada pelo programa podem ser exportadas para o excel, facilitando a obtenÃÃo do memorial e orÃamento da rede. / Water supply networks are important tools to ensure health and welfare. However, the process of designing these structures involves activities with very time consuming and repetitive steps. In order to reduce the time spent, ensuring quality and efficiency of the final project, the computer programs have acquired importance in space and engineering projects. UFC3 program is computer code developed in languagesAutoLISP, VBA (Visual Basic of Applications) and VB (Visual Basic), which has graphics capabilities to assist in developing projects within the AutoCAD environment. UFC3 was developed to help the process of drawing water distribution networks, enabling the automatic introduction of connections as well as the characteristic information of each node (pressure, elevation and hydraulic head), calculate the quantitative network, to generate a spreadsheet showing the results for parts. In addition, the program draws the longitudinal profile of water mains, including piezometric lines and maximum and minimum energy grade lines. In general, the connections are inserted automatically by the program, except for the cap. The sheets and quantitative results generated by the program can be exported to Excel, facilitating the acquisition of the design hystory and network budget.
8

Proposição de calibração de redes de sistemas de abastecimento de água através de método híbrido / A proposition for calibrating water distribution systems models using hybrid method

Narumi Abe 30 May 2014 (has links)
A popularização das tecnologias de monitoramento remoto possibilita e cria a necessidade do desenvolvimento de sistemas de calibração mais velozes, capazes de calibrar redes enquanto recebem dados, ou seja, em em tempo real. Este trabalho consistiu na proposição de dois novos métodos de calibração baseados em redes neurais artificiais construtivas, visando a aumentar a velocidade de processamento e a performance dos sistemas de calibração. O primeiro método consistiu em calibrar utilizando somente redes neurais artificiais. Um sistema foi desenvolvido para recorrentemente produzir respostas de modelos hidráulicos baseados no Epanet e transformá-los em padrões de treinamento para as RNA (redes neurais artificiais) construtivas. O segundo método consistiu no desenvolvimento de um sistema de calibração híbrido, utilizando as saídas da RNA do primeiro método para produzir valores para constituir a população inicial de soluções a serem buscadas usando os algoritmos genéticos (AG). Assim, pode-se considerar que o método híbrido proposto foi desenvolvido para produzir soluções a partir de boas aproximações para os valores ótimos. Os métodos propostos foram aplicados a quatro (4) setores de rede da cidade de Araraquara, SP. Os resultados das calibrações foram avaliados através da comparação das simulações e com os respectivos valores observados em campo, considerando critérios recomendados no Reino Unido. O primeiro método proposto mostrou-se pouco eficiente no processo de calibração, sendo útil, entretanto, como a primeira etapa da calibração através do método híbrido. O segundo método superou ligeiramente a performance obtida na qualidade da calibração dos dados de cargas de pressões e vazões comparadas com métodos de calibração clássicos e foi bastante superior no quesito velocidade. / The popularization of remote monitoring technologies allows and creates the need to develop faster calibration systems capable of calibrating networks while receiving data, i.e., in real time. This work consisted in proposing two new calibration methods based on constructive neural networks, aiming to increase the processing speed and performance of calibration systems. The first method was to calibrate using only artificial neural networks. A system was developed to produce responses of hydraulic models based on Epanet and turn them into training patterns for the constructive ANN (artificial neural networks) recurrently. The second method consisted in developing a hybrid calibration system using the outputs of the first method of RNA to produce values for the initial population of solutions to be searched using the genetic algorithms (GA). Thus, it can be considered that the hybrid method was developed to produce solutions from good approximations for the optimal values. The proposed methods were applied to four sectors of the city of Araraquara , SP. The results of the calibrations were evaluated by comparing the simulations and the respective values observed in the field, considering criteria recommended in the UK. The first proposed method proved inefficient in the calibration process, it is useful, however, as the first step of the calibration using the hybrid method. The second method was slightly better in performance obtained in the quality of the calibration data of pressures and flow rates compared with classical methods of calibration and it was quite superior in speed.
9

An ORISE Fellowship with the U.S. EPA: Advanced Water Quality Modeling for Water Security

Hagar, Jennifer Linn 26 August 2011 (has links)
No description available.
10

An Integrated Field-Scale Assessment of Chloramine Dynamics, By-Product Formation, and Nitrification Modeling

Alexander, Matthew T. 30 September 2010 (has links)
No description available.

Page generated in 0.0222 seconds