Directed Percolation
Mostrando 1-12 de 15 artigos, teses e dissertações.
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1. Transições de fase para estados absorventes: um estudo em redes regulares e complexas / Phase transitions to absorbing states: a study on regular and complex networks
Transições de fase para estados absorventes, configurações das quais o sistema não pode escapar, são atualmente um tópico na fronteira da física estatística fora do equilíbrio. Concomitantemente com um crescente interesse em tais transições de fase em topologias complexas, ainda há muitos problemas em aberto sendo investigados em redes regulares
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/07/2011
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2. Avalanches neuronais durante o ciclo sono-vigÃlia de ratos
Neuronal avalanches are spatiotemporal patterns of neuronal activity that occur spontaneously in supercial layers of the mammalian cortex under various experimental conditions. Previous studies in brain slices and cultured cells have shown that the distribution of sizes P(s) of neuronal avalanches obeys a power law relationship: P(s) Â sÂa , with exponent
Publicado em: 2009
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3. Dependence of the crossover exponent with the diffusion rate in the generalized contact process model
We study how the crossover exponent, phi, between the directed percolation (DP) and compact directed percolation (CDP) behaves as a function of the diffusion rate in a model that generalizes the contact process. Our conclusions are based in results pointed by perturbative series expansions and numerical simulations, and are consistent with a value phi = 2 fo
Brazilian Journal of Physics. Publicado em: 2008-03
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4. Neutralização de drenagem ácida de minas com escória de aciaria elétrica do forno-panela
The acid mine drainage (AMD) is formed when certain sulfide minerals are exposed to oxidizing conditions. The AMD is commonly associated with coal mining, especially in coal waste deposits that contain high pyrite (FeS2) concentration. The neutralization of AMD using alkaline materials, like limestone and steel slag is one of the useful remediation technique
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2007
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5. Dinâmica de populações em autômatos celulares / Cellular Automata Population Dynamics
The study of population dynamics becomes even more important nowadays because of its applications in a wide range of subjects, such as evolutive biology, ecology, economics and computational sciences, among many others. The use of networks, as well as cellular automata, to simulate populational dynamics is an ordinary tool because of its simplicity in the tr
Publicado em: 2006
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6. Universality classes of chaotic cellular automata
Cellular automata (CA) are discrete, spatially-homogeneous, locally-interacting dynamical systems of very simple construction, but which exhibit a rich intrinsic behavior. Even starting from disordered initial configurations, CA can evolve into ordered states with complex structures crystallized in space-time patterns. In this paper we concentrate on determi
Brazilian Journal of Physics. Publicado em: 2004-06
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7. Depinning transitions in interface growth models
Pinning-depinning transitions are roughening transitions separating a growing phase and pinned (or blocked) one, and are frequently connected to transitions into absorbing states. In this review, we discuss lattice growth models exhibiting this type of dynamic transition. Driven growth in media with impurities, the competition between deposition and desorpti
Brazilian Journal of Physics. Publicado em: 2003-09
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8. Catalysis with competitive reactions: static and dynamical critical behavior
We studied in this work a competitive reaction model between monomers on a catalyst. The catalyst is represented by hypercubic lattices in d = 1, 2 and 3 dimensions. The model is described by the following reactions: A + A -> A2 and A + B -> AB, where A and B are two monomers that arrive at the surface with probabilities yA and yB, respectively. The model is
Brazilian Journal of Physics. Publicado em: 2003-09
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9. Path integrals and perturbation theory for stochastic processes
We review and extend the formalism introduced by Peliti, that maps a Markov process to a path-integral representation. After developing the mapping, we apply it to some illustrative examples: the simple decay process, the birth-and-death process, and the Malthus-Verhulst process. In the first two cases we show how to obtain the exact probability generating f
Brazilian Journal of Physics. Publicado em: 2003-03
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10. Lattice model of replicators: aplication on prebiotic models and herpes ulcer / Dinâmica de replicação na rede: aplicações em modelos de evolução pré-biótica e de formação de úlceras
Two fundamental questions in the study of prebiotic evolution (origin of life) are concerned to the requisites for the persistence of small colonies of self-replicating molecules (replicators) and to the possibility that complex organisms evolve from simpler organisms as a result of mutations. These issues have been studied mainly in the chemical kinetics fo
Publicado em: 2001
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11. On possible experimental realizations of directed percolation
Directed percolation is one of the most prominent universality classes of nonequilibrium phase transitions and can be found in a large variety of models. Despite its theoretical success, no experiment is known which clearly reproduces the critical exponents of directed percolation. The present work compares suggested experiments and discusses possible reason
Brazilian Journal of Physics. Publicado em: 2000-03
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12. Paths to self-organized criticality
We present a pedagogical introduction to self-organized criticality (SOC), unraveling its connections with nonequilibrium phase transitions. There are several paths from a conventional critical point to SOC. They begin with an absorbing-state phase transition (directed percolation is a familiar example), and impose supervision or driving on the system; two c
Brazilian Journal of Physics. Publicado em: 2000-03