Vertex Models
Mostrando 1-12 de 14 artigos, teses e dissertações.
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1. O vértice D*Dp usando as regras de soma da QCD / The D*Dp vertex using the QCD sum rules
The particle physics have been studying topics like the Quark-Gluon Plasma (QGP), Higgs boson and dark matter, which require experiments in heavy-ion collisions. Therefore, accelerators capable of generate high energy particle beams are necessary and may generate new physics. When new data arise in the laboratories, new processes are necessary to explain thi
Publicado em: 2010
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2. Caminhadas determinísticas em redes complexas aplicadas em visão computacional / Determinist walks on complex applied in computer vision
Complex networks have received a growing interest in several areas of knowledge. This growth is mainly due to its flexibility in modeling and simulating topological structures that appear in our daily life. In most cases, complex networks characterization are based on basic measurements such as average degree, hierarchical degree, clustering coefficient, amo
Publicado em: 2010
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3. Ensaios analíticos e numéricos de processos estocásticos unidimensionais / Analytic and numeric essays on one-dimensional stochastic processes
Nesta presente tese, abordaremos três problemas sobre processos estocásticos unidimensionais governados pela equação mestra. Através do Ansatz do Produto Matricial (MPA) determinaremos as condições suficientes para garantir a integrabilidade de um novo processo de difusão num meio com impurezas. Investigando o espectro de tal modelo, computaremos o e
Publicado em: 2009
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4. O metodo de geração de colunas aplicado a problemas de otimização em grafos / Column generation technique applied to graph optimization problems
In this thesis, two combinatorial optimization problems are modeled by integer linear programming and solved using the column generation technique. Both cases correspond to generalizations of classical problems in graphs that occur in many practical situations. The first, called capacitated ring-star problem is a generalization of the vehicle routing problem
Publicado em: 2009
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5. An axisymmetric finite volume formulation for the solution of heat conduction problems using unstructured meshes
In this work, a finite volume formulation developed for two-dimensional models is extended to deal with axisymmetric models of heat conduction applications. This formulation uses a vertex centered finite volume method and it was implemented using an edge-based data structure. The time and domain discretization using triangular meshes is described in details,
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-12
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6. Grafos de mundos pequenos e difusão de inovações
This is a research in the area of Information Technology about how are the innovations disseminated in society. Taking the work of Everett Rogers (1962) about "diffusion of innovations" as reference, the study takes p1ace in the interface of this area with the fields of Sociology and Marketing, allowing evaluating how do the changes or new concepts are recei
Publicado em: 2005
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7. An edge-based unstructured finite volume procedure for the numerical analysis of heat conduction applications
In recent years, there has been a significant level of research on the application of unstructured mesh methods to the simulation of a variety of engineering and scientific problems. Great progress has been achieved in such area and one of the most successful methodologies consists on the use of the Finite Volume Method (FVM). The unstructured FV formulation
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2004-06
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8. SoluÃÃo numÃrica da equaÃÃo de difusÃo de calor em geometrias tridimensionais
This work presents a numeric formulation for the solution of the heat transfer equation with finite volume method (FVM) using forward Euler explicit time integration. The FVM was used because it satisfies the conservation principle, both locally as globally, since it is derived directly of the laws of conservation in the integral form. Also the FVM is well a
Publicado em: 2004
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9. Ansatz de Bethe para cadeias quânticas de spin-1 com condições de contorno
The procedure for obtaining integrable open spin chain Hamiltonians via reflection matrices explicitly carried out for some three-state vertex models. We have considered the 19-vertex models of Zamolodchikov-Fateev and Izergin-Korepin and the Z2 graded 19-vertex models with sl(2/1) and osp(1/2) invariances. In each case the eigenspectrum is determined by app
Publicado em: 2002
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10. Percolation transitions and wetting transitions in stochastic models
Stochastic models with irreversible elementary processes are introduced, and their macroscopic behaviors in the infinite-time and infinite-volume limits are studied extensively, in order to discuss nonequilibrium stationary states and phase transitions. The Domany-Kinzel model is a typical example of such an irreversible particle system. We first review this
Brazilian Journal of Physics. Publicado em: 2000-03
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11. Modelos de mecânica estatística exatamente solúveis em duas dimensões / Exactly solvable models of statistical mechanics in two dimensions
We study some spin and vertex systems which are exactly solvable in two dimensions. The exact solubility is connected to the existence of non trivial solutions of the factorization equations which allow us to determine the free energy in the thermodynamic limit. We introduce and solve by the inverse scattering method, a ten vertex model with two and three st
Publicado em: 1984
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12. Antenatal screening: its use in assessing obstetric risk factors in Zimbabwe.
STUDY OBJECTIVE--To assess the predictive utility of obstetric risk factors for identifying before the onset of labour those women at high risk of obstetric complications in a developing world setting, where home deliveries predominate and emergency transport is scarce. DESIGN--Risk factors derived from two population based, case-control studies (one of ceph