Bifurcation Analysis
Mostrando 13-24 de 60 artigos, teses e dissertações.
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13. Bifurcação de Hopf em um modelo para a dinâmica do vírus varicela-zoster / Hopf bifurcation in a model for the dynamics of varicella-zoster virus
Este trabalho propõe um sistema de equações diferenciais ordinárias composto por cinco equações não lineares acopladas, numa estrutura baseada no modelo SIR de Kermack e Mckendrick 1927, que visa descrever a dinâmica do vírus varicela-zoster na população de humanos. Da análise de seus pontos de equilíbrio verificamos o surgimento de uma bifurca�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 21/02/2011
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14. Nonlinear instabilities on a granular bed sheared by a turbulent liquid flow
The granular media is of great importance in our quotidian, and their transport by a fluid flow is frequently found in nature and in industry. When the shear stresses exerted by the fluid flow on a granular bed are bounded to some limits, a mobile granular layer known as bed-load takes place in which the grains stay in contact with the fixed part of the gran
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2011-09
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15. Population dynamics, life stage and ecological modeling in Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae)
In this study we investigated the population dynamics of Chrysomya albiceps (Wiedemann) with laboratory experiments, employing survival analysis and stage structure mathematical models, emphasizing survival among life stages. The study also assessed the theoretical influence of density dependence and cannibalism during immature stages, on the population dyna
Neotropical Entomology. Publicado em: 2011-04
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16. Robustness margins for indirect field-oriented control of induction motors
The influence of the rotor time constant mismatch on the stability of induction motors under indirect field-oriented control is analyzed. The results of [14] are generalized. A Lyapunov function which provides a global stability test and allows us to compute robustness margins is given. Different mechanisms for the loss of stability are detected by means of
Publicado em: 2011
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17. Medida do complexo médio-intimal carotídeo em adolescentes brasileiros do sexo masculino / CAROTID INTIMA-MEDIA THICKNESS IN MALE ADOLESCENTS
OBJECTIVES: Assess the carotid intima-media thickness (IMT) in a sample of male adolescents in a southern Brazil city, and investigate the association of this measure with biological and demographics variables. METHODS: Cross-sectional study in a random sample of 239 eighteen years old male adolescents, in the Pelotas city military recruitment, in the south
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/12/2010
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18. Linear and nonlinear aeroelastic analyses of a typical airfoil section with control surface freeplay.
This work presents an extensive analysis on the linear and nonlinear behavior of three degrees of freedom typical airfoil section oscillating in a bidimensional incompressible flow. The nonlinearity is introduced by means of control surface freeplay. The theoretical modeling of the aeroelastic system is reviewed from structural and aerodynamic standpoint. Tw
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/07/2010
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19. Linear and nonlinear aeroelastic analyses of a typical airfoil section with control surface freeplay.
This work presents an extensive analysis on the linear and nonlinear behavior of three degrees of freedom typical airfoil section oscillating in a bidimensional incompressible flow. The nonlinearity is introduced by means of control surface freeplay. The theoretical modeling of the aeroelastic system is reviewed from structural and aerodynamic standpoint. Tw
Publicado em: 2010
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20. Controle de caos e saltos entre atratores em um sistema com impactos / Control of caos and basin hopping in a system with impacts
For a mechanical system, described by the impact-pair model, we studied the control of chaos by a parametric perturbation and the basin-hopping phenomeno. For this nonintegrable system, we obtained numerically the evolution of its dynamical variables for a large set of initial conditions and control parameters. For this analysis, we used phase planes, Poinca
Publicado em: 2010
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21. Fermentação contínua de Zymomonas mobilis : modelagem, ajuste de parâmetros e inferências a partir do consumo de hidróxido de sódio
A bactéria Zymomonas mobilis atraiu considerável interesse nas últimas décadas devido ao seu metabolismo único e eficientes características fermentativas na produção de etanol a partir de açúcares simples. No entanto, apesar das aparentes vantagens na conversão e taxas específicas quando comparada com as leveduras, estas ainda dominam o mercado p
Publicado em: 2010
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22. A 3-D four-wing attractor and its analysis
In this paper, several three dimensional (3-D) four-wing smooth quadratic autonomous chaotic systems are analyzed. It is shown that these systems have a number of similar features. A new 3-D continuous autonomous system is proposed based on these features. The new system can generate a four-wing chaotic attractor with less terms in the system equations. Seve
Brazilian Journal of Physics. Publicado em: 2009-09
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23. Entanglement, bifurcation and chaos in the Jahn-Teller E x beta / Emaranhamento, bifurcação e caos no modelo de Jahn-Teller E x beta
In this work we realize a study of entanglement for the Jahn-Teller E Ä b model, wich describes the interaction of a qubit with an oscillator mode, and relate it with the bifurcation of the fixed point of the classical analogue of the model. We also study qualitatively the ocurrence of chaos and its variation as a function of the parameters of the system. W
Publicado em: 2009
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24. AvaliaÃÃo morfomÃtrica da regeneraÃÃo nervosa perifÃrica em animais desnutridos precocemente
The study evaluated the peripheral nerve regeneration in adult animals that were submitted to protein malnutrition during the period known as the critical window of development. We used 20 male rats, adult, Wistar line. During the period of lactation, parts of the mothers received diet hypoproteic (casein 8%) forming the group of malnourished pups (10 animal
Publicado em: 2009