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  • 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.
11

Regionalização de vazões máximas a partir do hidrograma unitário instantâneo geomorfológico em bacias embutidas na bacia hidrográfica do rio Ijuí-RS, com geometria hidráulica e geometria fractal / Regionalization of maximum flow from the Geomorphological Instant Unit Hydrograph in embedded sub-basins inside the Ijuí river basin - RS, with hydraulic geometry and fractal geometry

Pereira, Marco Alésio Figueiredo January 2015 (has links)
Em virtude da existência de falhas em séries históricas hidrológicas ou até mesmo da não existência de dados monitorados nas bacias de interesse, a regionalização hidrológica se configura como uma ferramenta propícia para preencher essa lacuna, tornando-se útil para o conhecimento e a gestão dos recursos hídricos. Existe na literatura da hidrologia uma gama de metodologias que abordam a regionalização de dados ambientais, como a análise de agrupamento, a curva de permanência, a regressão múltipla, entre outros. No entanto, o objetivo do presente trabalho foi regionalizar vazões máximas a partir do hidrograma unitário instantâneo geomorfológico em bacias embutidas, com inserção da geometria hidráulica e geometria fractal. Para tal, propõe-se uma metodologia, inserindo ao modelo do Hidrograma Unitário Instantâneo Geomorfológico (GIUH), novos parâmetros de “entrada”, a geometria hidráulica (GH), a geometria fractal (GF) e a precipitação média anual (Pma). Aplicou-se esta metodologia na bacia do rio Ijuí, localizada na região noroeste do Estado do Rio Grande do Sul. Para isto, foram necessárias as seguintes etapas de trabalho: determinar o comportamento pluviométrico da bacia em estudo; determinar as relações matemáticas (expoentes e coeficientes) da GH na seção transversal do exutório de cada bacia; determinar os valores da GF para cada bacia e inserir as informações da GH e da GF no GIUH. Os dados utilizados no presente estudo (dados de precipitações diárias, perfil topobatimétrico das seções, dados diários de cota, e dados diários de vazões e medições de vazões medidas em campo) foram observados e medidos em nove sub-bacias embutidas à bacia do rio Ijuí, monitoramento realizado por CPRM e IPH-UFRGS. Estes dados foram utilizados para determinar a precipitação média anual, parâmetros (expoentes e coeficientes) de GH e de GF. Com dados observados de sete eventos, ocorridos simultaneamente nas respectivas bacias, calibrou-se o modelo GIUH. Após calibrado o modelo, através de uma regressão multivariada, foram ajustadas equações lineares e potenciais que relacionam (velocidade) com parâmetros de GH, GF e Pma, visando regionalizar que é um parâmetro de entrada para a geração do GIUH. Com a inserção destes novos parâmetros validou-se o modelo, aplicando-o em outro evento distinto, no qual se pode observar que o modelo apresentou bons resultados quando comparado com os valores observados. / Because of the lack in hydrological time series or even the shortage of monitored data in the basins of interest, hydrological regionalization is configured as a good tool to fill this shortage, making it useful for water resource understanding and its management. In hydrology, there are methodologies that address the regionalization of environmental data, such as cluster analysis, the flow duration curve, multiple regression, etc. However, the main objective of this study is to develop a method of regionalization to estimate peak flows in watersheds. Thus, a method to use the model Geomorphological Instant Unit Hydrograph (GIUH), with the insertion of new input parameters, that is, hydraulic geometry (HG), fractal geometry (FG) and mean annual rainfall (Pma) was proposed. As a case study, this method was applied to the Ijuí river basin, located in the northwestern region of Rio Grande do Sul State. For this, several specific objectives were: Verification of the spatial homogeneity of the rainfall regime in the basin; determination of the mathematical relationships of HG in the cross section of outfall of each basin; determination of FG values for each basin; insertion of HG and FG information into GIUH. The data used in this study (daily rainfall data, cross sections profile, daily water-level data, daily discharge data) were observed and measured in nine embedded sub-basins inside the Ijuí river basin. The monitoring was carried out by CPRM and IPH-UFRGS. These data were used to determine the Pma, parameters (exponents and coefficients) of HG and FG. With data observed in seven events, occurred simultaneously in the respective basins, the GIUH model was calibrated. After the model calibration, linear and potential equations relating (speed) with parameters of HG, FG and Pma, that aimed to regionalize which is an input parameter for the generation of GIUH, were adjusted through a multivariate regression. With the insertion of these new parameters, the model was validated in another distinct event occurred in the basin, in which it can be observed the model showed good results when compared with observed values.
12

Higher Order Levelable Mrf Energy Minimization Via Graph Cuts

Karci, Mehmet Haydar 01 February 2008 (has links) (PDF)
A feature of minimizing images of a class of binary Markov random field energies is introduced and proved. Using this, the collection of minimizing images of levels of higher order, levelable MRF energies is shown to be a monotone collection. This implies that these images can be combined to give minimizing images of the MRF energy itself. Due to the recent developments, second and third order binary MRF energies of the mentioned class are known to be exactly minimized by maximum flow/minimum cut computations on appropriately constructed graphs. With the aid of these developments an exact and efficient algorithm to minimize levelable second and third order MRF energies, which is composed of a series of maximum flow/minimum cut computations, is proposed and applications of the proposed algorithm to image restoration are given.
13

Análise de critérios de outorga de direito de uso de recursos hídricos / Analysis of criteria for the granting of permits for the use of water

Bof, Luiz Henrique Nobre 05 July 2010 (has links)
Made available in DSpace on 2015-03-26T13:23:32Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4434030 bytes, checksum: ac93527e7501927b85ce1c540bebda4b (MD5) Previous issue date: 2010-07-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The compatibility of the criteria for the granting of permits for the use of water adopted by the Brazilian Federal and the State Governments is a significant improvement in the process of sharing water resources. Aiming to support the decision makers in the analysis of the granting process, this study evaluated the impact of the use of different criteria for permit in the Paracatu basin. It was evaluated the criterion corresponding to 30% of the annual Q7,10 (used by the Minas Gerais State Government), 70% of the annual Q95 (used by the Brazilian Federal Government), 30% of the monthly Q7,10 and 70% of the monthly Q95. The use of the criterion based on monthly flows enhances a better water management, since it allows a higher use of it when there is much availability of water, and imposes a higher restriction on critical periods. Replacing the use of the annual Q7,10 by the monthly Q7,10, the flow allowable for grants increased significantly in some months, for example, from December to May. It was observed that the criterion of 70% of the annual Q95 involves a high risk of drying rivers in the critical months, while the criterion of 70% of the monthly Q95 minimizes such risk. / A compatibilização dos critérios de outorga de direito de uso de recursos hídricos entre os órgãos gestores representa um expressivo avanço no processo de compartilhamento do uso da água. Visando dar subsídio aos órgãos gestores de recursos hídricos de forma a otimizar o uso da água, no presente trabalho avaliou-se o impacto do uso de diversos critérios de outorga na bacia do rio Paracatu. Foram avaliados os critérios correspondentes a 30% da Q7,10 anual (utilizado pelo órgão gestor de Minas Gerais), 70% da Q95 anual (utilizado pela órgão gestor da União), 30% da Q7,10 mensal e 70% da Q95 mensal. A utilização dos critérios baseados nas vazões mensais potencializa um melhor plano de utilização da água, à medida que permite um maior uso desse recurso nos períodos em que há maior disponibilidade hídrica e impõe uma restrição mais realista nos períodos críticos. A substituição do uso da Q7,10 anual pela Q7,10 mensal aumentaria expressivamente a vazão permissível para outorga em alguns meses, como, por exemplo, de dezembro a maio. Em relação à utilização do critério de 70% da Q95 anual evidenciou-se que este pode envolver um forte risco de secar o rio nos meses críticos, enquanto que o critério de 70% da Q95 mensal minimiza este risco em alguns meses.
14

Sistema computacional para a estimativa do escoamento superficial / Computacional system for estimating the runoff

Souza, Cristina D'ornellas Filipakis 30 July 2010 (has links)
Made available in DSpace on 2015-03-26T13:23:32Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1648259 bytes, checksum: 686967c8a87e84eb80c1fda048710266 (MD5) Previous issue date: 2010-07-30 / Runoff is the process of moving water on the soil surface and is part of the hydrological cycle. This process has some negative consequences for the environment, since this may be associated with water erosion, which also reduces the most fertile soil layer, also carries with lime, fertilizer and pesticides, which, in addition to environmental damage, promotes yet funding for agricultural activities. For such losses are avoided, it is necessary to understand the behavior of runoff, and the first step in this direction is to estimate it. Estimates of maximum flow and blade disposed are essential so that a better planning of works and actions to avoid or mitigate its consequences. The objective was to develop a software that would enable the estimation of maximum flow and blade surface runoff from the methods and Rational Curve Number respectively. It had been developed activity diagrams represent the functionality of the system, containing the various options available to the user. Then the system was implemented using the programming environment Delphi ® 2006 and was tested with dummy data of a watershed. The development of the system enabled the automation of calculations of maximum flow and blade disposed, which involve many variables and equations, ensuring greater speed in getting the value and reliability of them. / O escoamento superficial consiste no processo de movimento da água sobre a superfície do solo e é parte integrante do ciclo hidrológico. Este processo possui algumas consequências negativas para o meio ambiente, pois a este pode estar associado a erosão hídrica, que além de reduzir a camada mais fértil do solo, também leva consigo corretivos, fertilizantes e defensivos agrícolas, que, além dos prejuízos ambientais, promove ainda financeiros para a atividade agrícola. Para que tais prejuízos sejam evitados, faz-se necessário conhecer o comportamento do escoamento superficial, e o primeiro passo neste sentido consiste em estimá-lo. As estimativas da vazão máxima e da lâmina escoada são essenciais para que ocorra um melhor planejamento de obras e ações a fim de evitar ou amenizar suas consequências. O objetivo deste trabalho foi desenvolver um sistema computacional que possibilitasse a estimativa da vazão máxima e da lâmina do escoamento superficial a partir dos métodos Racional e Número da Curva respectivamente. Para tanto, foram desenvolvidos diagramas de atividades que representassem as funcionalidades do sistema, contendo as diversas opções disponibilizadas para o usuário. Então, o sistema foi implementado utilizando o ambiente de programação Delphi® 2006 e foi testado com dados fictícios de bacias hidrográficas. O desenvolvimento do sistema possibilitou a automatização dos cálculos da vazão máxima e da lâmina escoada, que envolvem muitas equações e variáveis, garantindo maior rapidez na obtenção dos valores e confiabilidade dos mesmos.
15

Development of a 3D Computational Vocal Fold Model Optimization Tool

Vaterlaus, Austin C. 09 June 2020 (has links)
One of the primary objectives of voice research is to better understand the biomechanics of voice production and how changes in properties of the vocal folds (VFs) affect voice ability and quality. Synthetic VF models provide a way to observe how changes in geometry and material property affect voice biomechanics. This thesis seeks to evaluate an approach of using a genetic algorithm to design synthetic VF models in three ways: first, through the development of a computationally cost-effective 3D vocal fold model; second, by creating and optimizing a variation of this model; and third, by validating the approach. To reduce computation times, a user-defined function (UDF) was implemented in low-fidelity 2D and 3D computational VF models. The UDF replaced the conventional meshed fluid domain with the mechanical energy equation. The UDF was implemented in the commercial finite element code ADINA and verified to produce results that were similar to those of 2D and 3D VF models with meshed fluid domains. Computation times were reduced by 86% for 2D VF models and 74% for 3D VF models while core vibratory characteristic changes were less than 5%. The results from using the UDF demonstrate that computation times could be reduced while still producing acceptable results. A genetic algorithm optimizer was developed to study the effects of altering geometry and material elasticity on frequency, closed quotient (CQ), and maximum flow declination rate (MFDR). The objective was to achieve frequency and CQ values within the normal human physiological range while maximizing MFDR. The resulting models enabled an exploration of trends between objective and design variables. Significant trends and aspects of model variability are discussed. The results demonstrate the benefit of using a structured model exploration method to create models with desirable characteristics. Two synthetic VF models were fabricated to validate predictions made by models produced by the genetic algorithm. Fabricated models were subjected to tests where frequency, CQ, and sound pressure level were measured. Trends between computational and synthetic VF model responses are discussed. The results show that predicted frequency trends between computational and synthetic models were similar, trends for closed quotient were inconclusive, and relationships between MFDR and sound pressure level remained consistent. Overall, while discrepancies between computational and synthetic VF model results were observed and areas in need of further study are noted, the study results provide evidence of potential for using the present optimization method to design synthetic VF models.
16

Maximum flow-based formulation for the optimal location of electric vehicle charging stations

Parent, Pierre-Luc 08 1900 (has links)
Due à l’augmentation de la force des changements climatiques, il devient critique d’éliminer les combustibles fossiles. Les véhicules électriques sont un bon moyen de réduire notre dépendance à ces matières polluantes, mais leur adoption est généralement limitée par le manque d’accessibilité à des stations de recharge. Dans cet article, notre but est d’agrandir l’infrastrucure liée aux stations de recharge pour fournir une meilleure qualité de service aux usagers (et une meilleure accessibilité aux stations). Nous nous attaquons spéficiquement au context urbain. Nous proposons de représenter un modèle d’assignation de demande de recharge à des stations sous la forme d’un problème de flux maximum. Ce modèle nous sert de base pour évaluer la satisfaction des usagers étant donné l’infrastruture disponible. Par la suite, nous incorporons le model de flux maximum à un programme en nombre entier mixte qui a pour but d’évaluer l’installation de nouvelles stations et d’étendre leur disponibilité en ajoutant plus de bornes de recharge. Nous présentons notre méthodologie dans le cas de la ville de Montréal et montrons que notre approche est en mesure résoudre des instances réalistes. Nous concluons en montrant l’importance de la variation dans le temps et l’espace de la demande de recharge lorsque l’on résout des instances de taille réelle. / With the increasing effects of climate change, the urgency to step away from fossil fuels is greater than ever before. Electric vehicles (EVs) are one way to diminish these effects, but their widespread adoption is often limited by the insufficient availability of charging stations. In this work, our goal is to expand the infrastructure of EV charging stations, in order to provide a better quality of service in terms of user satisfaction (and availability of charging stations). Specifically, our focus is directed towards urban areas. We first propose a model for the assignment of EV charging demand to stations, framing it as a maximum flow problem. This model is the basis for the evaluation of the user satisfaction by a given charging infrastructure. Secondly, we incorporate the maximum flow model into a mixedinteger linear program, where decisions on the opening of new stations and on the expansion of their capacity through additional outlets is accounted for. We showcase our methodology for the city of Montreal, demonstrating the scalability of our approach to handle real-world scenarios. We conclude that considering both spacial and temporal variations in charging demand is meaningful when solving realistic instances.
17

The Effects of Vocal Function Exercises on Aerodynamic Parameters for Children Receiving Voice Lessons

Sayles, Claire Lindsey 16 April 2003 (has links)
No description available.
18

Go with the flow : A study exploring public transit performance using a flow network model

Boman, Axel, Nilsson, Erik January 2020 (has links)
As opposed to public transit agencies' well-developed data generation capabilities, their utilization of their data is often overlooked. This study will tap into the potential of using the GTFS data format from an agency stakeholder perspective to assess transit performance. This format holds data for scheduled transit services, including real-time updates and network organization. The broad adaptation of GTFS by transit agencies (1240 transit networks in 672 locations worldwide) has made it a de-facto standard, making products built on top of it inherently scalable and could potentially be deployed in networks all over the world. The purpose of this thesis is two-fold; firstly, to explore how specific vulnerability features of nodes in a public transit network can be assessed using graph mining algorithms. Secondly, to develop a pipeline for aggregating GTFS data and fit it into a flow network model. The results include a data-driven framework for vulnerability characterization, a method for fitting GTFS data in a flow network model, and lastly, a definition for reduced flow capacity in a public transit context. Additionally, the results are presented in the setting of Uppsala's network (UL) and visualized with a web-based tool.
19

Studies on mathematical structures of network optimization problems / ネットワーク最適化問題の数学的構造に関する研究 / ネットワーク サイテキカ モンダイ ノ スウガクテキ コウゾウ ニカンスル ケンキュウ

渡辺 扇之介, Sennosuke Watanabe 20 September 2013 (has links)
本論文は,様々なネットワーク最適化問題の数学的構造について様々な観点から調べたものである.主たる結果はネットワーク最適化問題の代表例である最大流問題に,関するいくつかの結果と,Min-Plus代数に値をもつ行列の固有値と固有ベクトルに関する特徴づけに関する結果からなっている. / 博士(理学) / Doctor of Philosophy in Science / 同志社大学 / Doshisha University
20

INTERFACE DE ANÁLISE DA INTERCONEXÃO EM UMA LAN USANDO CORBA / Software development (graphical user interface) that makes possible to analyze the interconnection in a LAN (Local Area Network) using CORBA (Common Object Request Broker Architecture)

MONTEIRO, Milson Silva 07 June 2002 (has links)
Made available in DSpace on 2016-08-17T14:52:43Z (GMT). No. of bitstreams: 1 Milson Monteiro.pdf: 1924077 bytes, checksum: 78f931b493f756dec0edee7a465e1099 (MD5) Previous issue date: 2002-06-07 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This works concern software development (graphical user interface) that makes possible to analyze the interconnection in a LAN (Local Area Network) using CORBA (Common Object Request Broker Architecture) on distributed and heterogeneous environment among several outlying machines. This works presents paradigms of graphs theory: shortest paths problems (Dijkstra-Ford-Moore-Belman), maximum flow problems (Edmonds-Karp) and minimum cost flow problems (Busacker-Gowen) to formalize the interface development. We discoursed on the graphs theory and networks flows that are essentials to guarantee theoretical insight. / O objeto de estudo deste trabalho é o desenvolvimento de um software (interface gráfica do usuário) que possibilita analisar a interconexão de uma LAN (Local Area Network) usando CORBA (Common Object Request Broker Architecture) em ambientes distribuídos e heterogêneos entre diversas máquinas periféricas. Este trabalho apresenta os paradigmas da teoria de grafos: menor caminho (Dijkstra, Ford-Moore-Belman), fluxo máximo (Edmonds-Karp) e fluxo de custo mínimo (Busacker-Gowen) para formalizar o desenvolvimento da interface. Discorremos sobre a teoria de grafos e fluxos em redes que são relevantes para garantir o embasamento teórico.

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