14,656 research outputs found
Comment on: Kinetic Roughening in Slow Combustion of Paper
We comment on a recent Letter by Maunuksela et al. [Phys. Rev. Lett. 79, 1515
(1997)].Comment: 1 page, 1 figure, http://polymer.bu.edu/~hmakse/Home.htm
A Study of Cool White Dwarfs in the Sloan Digital Sky Survey Data Release 12
In this work we study white dwarfs where to compare the differences in the
cooling of DAs and non-DAs and their formation channels. Our final sample is
composed by nearly DAs and more than non-DAs that are
simultaneously in the SDSS DR12 spectroscopic database and in the \textit{Gaia}
survey DR2. We present the mass distribution for DAs, DBs and DCs, where it is
found that the DCs are more massive than DAs and
DBs on average. Also we present the photometric effective temperature
distribution for each spectral type and the distance distribution for DAs and
non-DAs. In addition, we study the ratio of non-DAs to DAs as a function of
effective temperature. We find that this ratio is around for
effective temperature above and increases by a factor
of five for effective temperature cooler than . If we assume
that the increase of non-DA stars between to
is due to convective dilution, per cent of
the DAs should turn into non-DAs to explain the observed ratio. Our
determination of the mass distribution of DCs also agrees with the theory that
convective dilution and mixing are more likely to occur in massive white
dwarfs, which supports evolutionary models and observations suggesting that
higher mass white dwarfs have thinner hydrogen layers.Comment: 9 pages, 10 figures, accepted by MNRA
Dynamics of Surface Roughening with Quenched Disorder
We study the dynamical exponent for the directed percolation depinning
(DPD) class of models for surface roughening in the presence of quenched
disorder. We argue that for dimensions is equal to the exponent
characterizing the shortest path between two sites in an
isotropic percolation cluster in dimensions. To test the argument, we
perform simulations and calculate for DPD, and for
percolation, from to .Comment: RevTex manuscript 3 pages + 6 figures (obtained upon request via
email [email protected]
Ising Model on Edge-Dual of Random Networks
We consider Ising model on edge-dual of uncorrelated random networks with
arbitrary degree distribution. These networks have a finite clustering in the
thermodynamic limit. High and low temperature expansions of Ising model on the
edge-dual of random networks are derived. A detailed comparison of the critical
behavior of Ising model on scale free random networks and their edge-dual is
presented.Comment: 23 pages, 4 figures, 1 tabl
Canalizing Kauffman networks: non-ergodicity and its effect on their critical behavior
Boolean Networks have been used to study numerous phenomena, including gene
regulation, neural networks, social interactions, and biological evolution.
Here, we propose a general method for determining the critical behavior of
Boolean systems built from arbitrary ensembles of Boolean functions. In
particular, we solve the critical condition for systems of units operating
according to canalizing functions and present strong numerical evidence that
our approach correctly predicts the phase transition from order to chaos in
such systems.Comment: to be published in PR
Directed Surfaces in Disordered Media
The critical exponents for a class of one-dimensional models of interface
depinning in disordered media can be calculated through a mapping onto directed
percolation (DP). In higher dimensions these models give rise to directed
surfaces, which do not belong to the directed percolation universality class.
We formulate a scaling theory of directed surfaces, and calculate critical
exponents numerically, using a cellular automaton that locates the directed
surfaces without making reference to the dynamics of the underlying interface
growth models.Comment: 4 pages, REVTEX, 2 Postscript figures avaliable from [email protected]
Mapeamento do risco de frio durante o período reprodutivo do arroz irrigado no Rio Grande do Sul.
bitstream/item/32412/1/documento-108.pd
Experimental determination of the non-extensive entropic parameter
We show how to extract the parameter from experimental data, considering
an inhomogeneous magnetic system composed by many Maxwell-Boltzmann homogeneous
parts, which after integration over the whole system recover the Tsallis
non-extensivity. Analyzing the cluster distribution of
LaSrMnO manganite, obtained through scanning tunnelling
spectroscopy, we measure the parameter and predict the bulk magnetization
with good accuracy. The connection between the Griffiths phase and
non-extensivity is also considered. We conclude that the entropic parameter
embodies information about the dynamics, the key role to describe complex
systems.Comment: Submitted to Phys. Rev. Let
Micro-bias and macro-performance
We use agent-based modeling to investigate the effect of conservatism and
partisanship on the efficiency with which large populations solve the density
classification task--a paradigmatic problem for information aggregation and
consensus building. We find that conservative agents enhance the populations'
ability to efficiently solve the density classification task despite large
levels of noise in the system. In contrast, we find that the presence of even a
small fraction of partisans holding the minority position will result in
deadlock or a consensus on an incorrect answer. Our results provide a possible
explanation for the emergence of conservatism and suggest that even low levels
of partisanship can lead to significant social costs.Comment: 11 pages, 5 figure
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