Mean Field Approximation
Mostrando 1-12 de 36 artigos, teses e dissertações.
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1. Mudança de opinião em redes complexas: aproximação de campo médio para o modelo Sznajd / Opinion dynamics in complex networks: mean-field approximation to Sznajd model
Esta dissertação discutirá, com uma abordagem predominantemente analítica, aspectos em aberto do Modelo Sznajd e de algumas de suas variantes. Apresentaremos uma equação mestra que descreve a evolução de opiniões para o modelo e estudaremos seus estados estacionários numa aproximação de campo médio. Mostraremos que esta simples abordagem é sufi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/05/2011
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2. Transmissão vertical e horizontal de parasitas usando autômatos celulares probabilísticos
Uma ampla faixa de patógenos são propagados por uma combinação de transmissão horizontal e vertical, dentre os quais podemos destacar: microesporídeos, helmintos, bactérias, fungos e vírus de plantas e animais, incluindo importantes microorganismos parasitas de humanos como o HIV, HTLV-1, cytomegalovírus, vários tipos de hepatite e herpes simples [
Publicado em: 2011
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3. CONSTRUCTION OF AN COMPACT SQUID MAGNETOMETER FOR CHARACTERIZATION OF THE MAGNETIC NANOPARTICLES USED IN BIOLOGICAL ASSAYS / CONSTRUÇÃO DE UM MAGNETÔMETRO SQUID COMPACTO PARA CARACTERIZAÇÃO DE NANOPARTÍCULAS MAGNÉTICAS UTILIZADAS EM ENSAIOS BIOLÓGICOS
The immunoassay is an important tool in clinical diagnostics and in fundamental research. Magnetic nanoparticles, bound with antibodies, have been applied increasingly for various immunoassays with the purpose of separation and quantification of antigens. We developed a system based on bulk SQUIDs for detecting the field generated from remanent magnetization
Publicado em: 2010
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4. Gas de Bose diluido fracamente confinado / Dilute Bose gas weakly confined
A critical study of atomic Bose-Einstein condensates (BECs) is presented. Taking as a starting point the physics of the free gas, we study the effect of weakly confining potentials. Two cases were studied in detail: i) an atomic gas in a finite square well potential with a few bound states; and ii) a system confined in two-dimensions by an isotropic harmonic
Publicado em: 2010
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5. Andreev transport in double quantum dots coupled to superconductor and ferromagnetic leads / Transporte por reflexão de Andreev em pontos quanticos duplos acoplados a eletrodos supercondutores e ferromagneticos
In this work we studied the quantum transport in two hybrid nanostructures composed of double quantum dots (DQD)s coupled to superconductor (S) and ferromagnetic (F) leads. The first nanostructure, denoted by F - QDa - QDb - S, is composed of a ferromagnet, two quantum dots, and a superconductor connected in series. In the second nanostructure, denoted by (
Publicado em: 2010
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6. INVESTIGAÇÃO INTERFEROMÉTRICA DA REAÇÃO HF SÍLICA (SIO2) EM PRESENÇA DE CAMPOS ELÉTRICOS
O ataque químico de sílica (SiO2) por ácido fluorídrico (HF) é uma reação importante, usada na fabricação de circuitos integrados, cujo mecanismo não é ainda totalmente entendido. Um aspecto curioso desta reação é que sua velocidade pode ser alterada por campos elétricos na interface ácido-sílica. Um modelo teórico para explicar este efeito
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 08/12/2009
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7. Extended Bell´s Be-ables and Atenuattion × Amplification Competition. / Extensão dos Be-ables de Bell e Competição Atenuação x Amplificação
In the first part of this work we employ the Itô stochastic equation to extend Bells be-able interpretation of quantum mechanics to encompass dissipation, decoherence and quantum-to-classical transition through quantum trajectories. For a particular choice of the source of stochasticity, the one leading to a dissipative Lindblad type correction to the Hamil
Publicado em: 2009
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8. Dipole scattering amplitude in momentum space: investigating fluctuations at HERA
We extend a recently proposed dipole model which relates the virtual photon-proton cross section to the dipole-proton forward scattering amplitude in momentum space investigating the effects of the gluon number fluctuations. The model interpolates between well known asymptotic behaviours predicted by perturbative QCD from the Balitsky-Kovchegov equation, whi
Brazilian Journal of Physics. Publicado em: 2008-09
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9. Phase diagram of quark matter in nonlocal chiral models under color and electric charge neutrality conditions
We consider the phase diagram of two-flavor quark matter under neutron star constraints for the case of two nonlocal, covariant quark models within the mean field approximation. In one of these models (Model I) the nonlocality arises from the regularization procedure, motivated by the instanton liquid model, whereas in the second one (Model II) a separable a
Brazilian Journal of Physics. Publicado em: 2007-07
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10. Análise da dispersão de larvas de lagostas no Atlântico tropical a partir de correntes geotróficas superficiais derivadas por satélites / Use of geostrophic currents derived from radar altimeter to study lobster larvae dispersion in the tropical atlantic
Three species of spiny lobster are harvested along the Brazilian coast (Panulirus argus, P. laevicauda and P. echinatus). The annual revenue amounts 50 to 60 million US dollars. These species have a relatively long planktonic larval phase (about one year), that enables the mean ocean currents to transport the larvae over long distances away from the original
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/05/2006
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11. Center-of-mass correction in a relativistic Hartree approximation
We use the Peierls-Yoccoz projection method to evaluate the center-of-mass correction of a relativistic system of nucleons and sigma and omega mesons, described in a mean-field Hartree approach. This correction for 4He, 16O and 40Ca is compared with the pure harmonic oscillator center-of-mass energy correction.
Brazilian Journal of Physics. Publicado em: 2006-12
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12. Use of geostrophic currents derived from radar altimeter to study lobster larvae dispersion in the tropical atlantic / Análise da dispersão de larvas de lagostas no Atlântico tropical a partir de correntes geotróficas superficiais derivadas por satélites
Three species of spiny lobster are harvested along the Brazilian coast (Panulirus argus, P. laevicauda and P. echinatus). The annual revenue amounts 50 to 60 million US dollars. These species have a relatively long planktonic larval phase (about one year), that enables the mean ocean currents to transport the larvae over long distances away from the original
Publicado em: 2006