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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.
71

Multiplicity of positive solutions of even-order nonhomogeneous boundary value problems

Hopkins, Britney. Henderson, Johnny. January 2009 (has links)
Thesis (Ph.D.)--Baylor University, 2009. / Includes bibliographical references (p. 77-79).
72

Comportamento evolutivo de uma pluma superficial de poluente na bacia hidrográfica do Rio Mogi Guaçu / Evolutionary behavior of a surface plume in the hydrographic basin of the Mogi Guaçu River

Carniato, Nínive Katarina Soares 16 August 2018 (has links)
Orientadores: Raul Vinhas Ribeiro, João Frederico da Costa Azevedo Meyer / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-16T06:14:03Z (GMT). No. of bitstreams: 1 Carniato_NiniveKatarinaSoares_M.pdf: 8054847 bytes, checksum: f4befcf7d2c4254d4a290c4e962ba0f0 (MD5) Previous issue date: 2010 / Resumo: Um dos maiores desafios atuais é encontrar uma ferramenta adequada que contribua para a melhoria da interpretação de informações referentes aos impactos ambientais em corpos aquáticos, visto que a qualidade das águas afeta diretamente a civilização humana. Este trabalho apresenta o estudo do comportamento evolutivo, como primeira aproximação, a partir de dados coletados, de uma carga poluidora dos Compartimentos Alto Mogi e Peixe pertencentes à Bacia Hidrográfica do Rio Mogi Guaçu, localizada na região nordeste do estado de São Paulo. Contando com 72 municípios, o Rio Mogi Guaçu é de extrema importância para o desenvolvimento industrial e urbano dos municípios ribeirinhos. Porém, esse mesmo desenvolvimento afeta de modo impactante o rio em questão e prejudica de modo significativo a fauna e ora da região. Com o intuito de analisar e propor métodos de combater e prevenir a poluição do rio foi usada Equações de Diferenças para modelar o comportamento da carga poluidora despejada no rio e criaram-se simulações computacionais em MATLAB que mostram cenários para futuras intervenções de recuperação da qualidade ambiental / Abstract: One of the biggest challenges today is finding an appropriate tool to contribute to improving the interpretation of information relating to environmental impacts in water bodies. Since the water quality directly affects human civilization. This work presents the study of the evolutionary behavior, as a first approximation, from data collected, of a pollutant load of the Compartments High Mogi and Fish belonging to the Hydrographic Basin of the Mogi Guaçu River, situated in the northeastern region of state of São Paulo, Brazil. Has 72 municipalities, the Mogi Guaçu is of extreme importance to industrial development and urban municipalities of the Mogi Guaçu river. But such a development affects so impacting the river in question and significantly affect the environment. In order to analyze and propose methods to combat and prevent pollution of the river, was used Difference Equations to model the behavior of the pollutant load discharged into the river and created computer simulations in MATLAB to show scenarios for future interventions in the recovery of environmental quality / Mestrado / Automação / Mestre em Engenharia Elétrica
73

Equações de diferenças finitas na modelagem da hanseniase em Imperatriz - MA / Modelling the hanseniase of Imperatriz - MA, Brazil

Sales e Silva, José Gilson 13 August 2018 (has links)
Orientador: Rodney Carlos Bassanezi / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação Cientifica / Made available in DSpace on 2018-08-13T04:06:10Z (GMT). No. of bitstreams: 1 SaleseSilva_JoseGilson_M.pdf: 1291910 bytes, checksum: b6f441a8e24badc2915c8f5301ca28ce (MD5) Previous issue date: 2009 / Resumo: Apresentamos uma abordagem resumida da epidemiologia matemática, dos modelos epidemiológicos tipo SI, SIS e SIR, bem como um embasamento sobre as equações de diferenças finitas. Utilizamos um modelo matemático determinístico em tempo discreto tipo SI, simplificado, para interpreta¸c¿ao e análise da epidemia de hanseníase do município de Imperatriz-MA, com base em dados relativos ao número de contatos registrados e casos notificados no per'iodo de 1994 a 2007. Apresentamos também uma validação do modelo e histórico da epidemia em Imperatriz. / Abstract: We present an approach summarized from epidemiology mathematics , from the models epidemiological type Oneself SI SS e SIR , as well as a basement on the subject of the equations of differences finite. Uses a model mathematical deterministic in time discreet type SI about to interpretation e analysis from epidemics from hansen'iase of the county of Imperatriz-MA , based on dice relative the number of contacts registered e cases notifying into the period of 1994 the 2007. We present also a validation of the model e historical from epidemics in the Imperatriz. / Mestrado / Biomatematica / Mestre em Matemática
74

Numerical modelling of single and two phase fluid flow and energy transport in rigid and deforming porous media

Roberts, Peter John January 1987 (has links)
No description available.
75

Invading a Structured Population: A Bifurcation Approach

Meissen, Emily Philomena, Meissen, Emily Philomena January 2017 (has links)
Matrix population models are discrete in both time and state-space, where a matrix with density-dependent entries is used to project a population vector of a stage-structured population from one time to the next. Such models are useful for modeling populations with discrete categorizations (e.g. developmental cycles, communities of multiple species, differing sizes, etc.). We present a general matrix model of two interacting populations where one (the resident) has a stable cycle, and we analyze when the other population (the invader) can successfully invade. Specifically, we study the local bifurcations of coexistence cycles as the resident cycle destabilizes, where a cycle of length 1 corresponds to an equilibrium. We make no assumptions on the types of interactions between the populations or on the population structure of the resident; we consider when the invader's projection matrix is primitive or imprimitive and 2x2. The simplest biological scenarios for such structures are an iteroparous invader and a two-stage semelparous invader. When the invader has a primitive projection matrix, coexistence cycles (of the same period as the resident cycle) bifurcate from the resident-cycle. When the invader has an imprimitive two-stage projection matrix, two types of coexistence cycles bifurcate from the resident-cycle: cycles of the same period and cycles of double the period. In both the primitive and imprimitive cases, we provide diagnostic quantities to determine the direction of bifurcation and the stability of the bifurcating cycles. Because we only perform a local stability analysis, the only successful invasion provided by our results is through stable coexistence cycles. As we show in some simple examples, however, the invader may persist when the coexistence cycles are unstable through competitive exclusion where the branch of bifurcating cycles connects to a branch of invader attractors and creates a multi-attractor scenario known as a strong Allee effect.
76

Variability in experimental color matching conditions: effects of observers, daylight simulators, and color inconstancy

Mangine, Heather Noelle 14 July 2005 (has links)
No description available.
77

Lower ramification numbers of wildly ramified power series

Fransson, Jonas January 2014 (has links)
In this thesis we study lower ramification numbers of power series tan- gent to the identity that are defined over fields of positive characteristics. Let f be such a series, then f has a fixed point at the origin and the corresponding lower ramification numbers of f are then, up to a constant, the multiplicity of zero as a fixed point of iterates of f. In this thesis we classify power series having ‘small’ ramification numbers. The results are then used to study ramification numbers of polynomials not tangent to the identity. We also state a few conjectures motivated by computer experiments that we performed.
78

Equações de diferenças dinâmica cobweb e ajustes adaptativos / Difference equations cobweb dynamics and adaptative-adjustments

Gunella, Michel 08 December 2016 (has links)
Quando um capital é alugado ou investido, uma parte age como o credor e o outro como o mutuário. O credor é o proprietário do capital e, como prêmio, o mutuário paga juros ao credor para o uso do capital do credor. Por exemplo, quando o dinheiro é depositado em uma conta poupança, o depositante é o credor e o banco é o mutuário. Este fenômeno gera uma dinâmica, este é o tema principal desta dissertação. Consideramos alguns modelos clássicos sob o ponto de vista das equações de diferenças, com ênfase no estudo da existência de um equilíbrio bem como as condições especiais para a sua estabilidade de soluções. / When capital is rented or invested, one part acts as the lender and the other one as the borrower. The lender is the owner of the capital, and, as prize, the borrower pays interest to the lender for the use of the lenders capital. For example, when money is deposited in a savings account, the depositor is the lender and the bank is the borrower. This phenomenon generates a dynamic, this is the main theme of this dissertation. We consider some classical models from the point of view of the difference equations, with emphasis on the study of the existence of an equilibrium as well the special conditions for its stability of solutions.
79

Optimal harvesting models for metapopulations / Geoffrey N. Tuck.

Tuck, Geoffrey N. (Geoffrey Neil) January 1994 (has links)
Bibliography: leaves 217-238. / ix, 238 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1995?
80

Equações de diferenças dinâmica cobweb e ajustes adaptativos / Difference equations cobweb dynamics and adaptative-adjustments

Michel Gunella 08 December 2016 (has links)
Quando um capital é alugado ou investido, uma parte age como o credor e o outro como o mutuário. O credor é o proprietário do capital e, como prêmio, o mutuário paga juros ao credor para o uso do capital do credor. Por exemplo, quando o dinheiro é depositado em uma conta poupança, o depositante é o credor e o banco é o mutuário. Este fenômeno gera uma dinâmica, este é o tema principal desta dissertação. Consideramos alguns modelos clássicos sob o ponto de vista das equações de diferenças, com ênfase no estudo da existência de um equilíbrio bem como as condições especiais para a sua estabilidade de soluções. / When capital is rented or invested, one part acts as the lender and the other one as the borrower. The lender is the owner of the capital, and, as prize, the borrower pays interest to the lender for the use of the lenders capital. For example, when money is deposited in a savings account, the depositor is the lender and the bank is the borrower. This phenomenon generates a dynamic, this is the main theme of this dissertation. We consider some classical models from the point of view of the difference equations, with emphasis on the study of the existence of an equilibrium as well the special conditions for its stability of solutions.

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