Dissipative Systems
Mostrando 13-24 de 35 artigos, teses e dissertações.
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13. A study of decoherence processes in solid state qubits / Um estudo sobre processos de descoerencia em qubits de estado solido
Esta tese teve como objetivo estudar processos de perda de coerência quântica, chamados de descoerência, em sistemas de matéria condensada eleitos pela literatura como possíveis implementações do bit quântico (qubit). Esta perda de coerência quântica ocorre devido ao inevitável acoplamento do sistema de interesse com o seu ambiente. Como os estado
Publicado em: 2006
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14. Systems Biology: an information-theoretic-based thermo-statistical approach
Systems Biology (system-level understanding in biological science), from the physical-chemical point of view, is involved with irreversible thermodynamics and nonlinear kinetic theory of open systems which are founded on nonequilibrium statistical mechanics. We describe a modern thermo-statistical approach for dealing with complex systems, in particular biol
Brazilian Journal of Physics. Publicado em: 2004-06
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15. Comportamento assintótico de sistemas não lineares discretos / Asymptotic behavior of non lineal discrete systems
Firstly, in this work, we present a study of part of two works by J. P. LaSalle, concerning with asymptotic behavior of discrete systems. Secondly, we study the dynamics of a discrete system that depends on a parameter l in L, of the form x(n+1) = f(x(n), l). As part of this general purpose, we develop tecniques to obtain uniform estimates (with respect to t
Publicado em: 2004
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16. Decoerencia de spin eletronico em pontos quanticos
In the perspective of quantum computation, two levels systems are the best candidates to implement the so called quantum bits. In special, the possibility of growing quantum dots capable of storing one electron makes it plausible to use electronic spin for such devices. Nevertheless, one of the big concerns is the time the electron takes to lose coherence. I
Publicado em: 2003
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17. Emissão de metano por reservatórios hidrelétricos amazônicos através de leis de potência. / Methane emission of Amazonian hydroelectric reservoirs from Powerlaw relations.
Este trabalho tem por objetivo avaliar a emissão de metano em dois reservatórios amazônicos, Tucuruí e Samuel. A análise leva em consideração flutuações da área/cota e medidas isotópicas e de fluxos de d13CH4 obtidas em campo, as quais são influenciadas por diversos fatores simultaneamente, como ventos, pressão atmosférica, oxidação na coluna
Publicado em: 2002
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18. Investigações sobre as relações de escala dos sistemas estelares auto-gravitantes / Investigations on the scaling relations of self-gravitating stellar systems
We aim in this work to collect several numerical and analitical investigations concerning the origin of the scaling relations of the self-gravitating stellar systems. These relations depend on a very small number of independent physical parameters that reduce and confine the observational constraints to a plane in this parameter space, called the ""Fundament
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 200105
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19. Uma contribuição ao estudo de sistemas dinamicos giroscopicos não-lineares
In this work one develops the study of the linear gyroscopic dynamical system of the conservative and of the dissipative kinds giving emphasis to the study of the stability of these systems as a important condition to the comprehension of the nonlinear gyroscopic system, the main goal of this work. In the study of the linear system one presents the mathemati
Publicado em: 2001
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20. Investigations on the scaling relations of self-gravitating stellar systems / Investigações sobre as relações de escala dos sistemas estelares auto-gravitantes
We aim in this work to collect several numerical and analitical investigations concerning the origin of the scaling relations of the self-gravitating stellar systems. These relations depend on a very small number of independent physical parameters that reduce and confine the observational constraints to a plane in this parameter space, called the ""Fundament
Publicado em: 2001
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21. Considerations on nonequilibrium entropy and temperature
Several aspects of the Thermodynamics of systems away from equilibrium are considered. Particular attention is given to the question of the concepts of entropy and temperature in arbitrary nonequilibrium conditions. Even though such state function and thermodynamic variable are elusive in such conditions, it is elaborated and discussed an approach to them th
Brazilian Journal of Physics. Publicado em: 2000
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22. Aspectos dinamicos de sistemas quanticos abertos
Dynamical aspects of three open quantum systems are examined. In the problem of quantum particle trapping by oscillating fields there is the evidence of movement stabilization and the quadrature-squeezing degradation for the quantum particle, due to the dissipative action of the environment over the particle. In the problem of information transfer occuring i
Publicado em: 1999
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23. REDUÇÃO DE ORDEM DE MODELOS MECÂNICOS LINEARES: UMA ABORDAGEM VIA GRAFOS DE LIGAÇÃO / ORDER REDUCTION OF LINEAR MECHANICAL MODELS: A BOND GRAPH APPROACH
It is described in this work a Bond Graph based procedure to the development of linear mechanical systems reduced order models. From the analysis of the topological structure of the main mechanical models represented by this technique it was established a new formulation that permits to obtain several mathematical representation forms and it was defined a ge
Publicado em: 1995
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24. LOCALIZAÇÃO ÓTIMA DE SENSORES PARA FILTRAGEM E IDENTIFICAÇÃO EM SISTEMAS DISTRIBUÍDOS / OPTIMAL SENSORS LOCATION FOR FILTERING AND IDENTIFICATION OF DISTRIBUTED SYSTEMS
This thesis deals with the nonlinear problem of simultaneous parameter and state estimation for distributed systems, including the associated optimal sensor location. The class of models under consideration is caracterrized by linear unbounded operators which are densely defined and dissipative. Our approach applies linear filtering techniquess to a sequence
Publicado em: 1987