27 research outputs found
Anomalous diffusion and anisotropic nonlinear Fokker-Planck equation
We analyse a bidimensional nonlinear Fokker-Planck equation by considering an
anisotropic case, whose diffusion coefficients are
and with . In this
context, we also investigate two situations with the drift force
. The first one is characterized by
and the second is given by and
. In these cases, we can verify an anomalous behavior induced in
different directions by the drift force applied. The found results are exact
and exhibit, in terms of the -exponentials, functions which emerge from the
Tsallis formalism. The generalization for the -dimensional case is
discussed.Comment: 6 pages, tex fil
q-exponential, Weibull, and q-Weibull distributions: an empirical analysis
In a comparative study, the q-exponential and Weibull distributions are
employed to investigate frequency distributions of basketball baskets, cyclone
victims, brand-name drugs by retail sales, and highway length. In order to
analyze the intermediate cases, a distribution, the q-Weibull one, which
interpolates the q-exponential and Weibull ones, is introduced. It is verified
that the basketball baskets distribution is well described by a q-exponential,
whereas the cyclone victims and brand-name drugs by retail sales ones are
better adjusted by a Weibull distribution. On the other hand, for highway
length the q-exponential and Weibull distributions do not give satisfactory
adjustment, being necessary to employ the q-Weibull distribution. Furthermore,
the introduction of this interpolating distribution gives an illumination from
the point of view of the stretched exponential against inverse power law
(q-exponential with q > 1) controversy.Comment: 6 pages, Latex. To appear in Physica
On the equivalence of the self-dual and Maxwell-Chern-Simons models coupled to Fermions
We study the exact equivalence between the self-dual model minimally coupled
with a Dirac field and the Maxwell-Chern-Simons model with non-minimal magnetic
coupling to fermions. We show that the fermion sectors of the models are
equivalent only if a Thirring like interaction is included. Using functional
methods we verify that, up to renormalizations, the equivalence persists at the
quantum level.Comment: 8 pages, revte
Regularities in football goal distributions
Besides of complexities concerning to football championships, it is
identified some regularities in them. These regularities refer to goal
distributions by goal-players and by games. In particular, the goal
distribution by goal-players it well adjusted by the Zipf-Mandelbrot law,
suggesting a conection with an anomalous decay.Comment: (Universidade Estadual de Maringa - Brazil) Latex, 3 pages, 3 ps
figure
Anomalous diffusion, nonlinear fractional Fokker-Planck equation and solutions
We obtain new exact classes of solutions for the nonlinear fractional
Fokker-Planck-like equation partial_t rho = partial_x{D(x) partial^{mu -1}_x
rho^{nu} - F(x) rho} by considering a diffusion coefficient D = D|x|^{-theta}
(theta in R and D>0) and a drift force F = -k_1 x + k-bar_{gamma}
x|x|^{gamma-1} (k_1, k-bar_{gamma}, gamma in R). Connection with nonextensive
statistical mechanics based on Tsallis entropy is also discussed.Comment: latex, 5 pages. Submitted to Physica
An Improved Description of the Dielectric Breakdown in Oxides Based on a Generalized Weibull distribution
In this work, we address modal parameter fluctuations in statistical
distributions describing charge-to-breakdown and/or
time-to-breakdown during the dielectric breakdown regime of
ultra-thin oxides, which are of high interest for the advancement of electronic
technology. We reobtain a generalized Weibull distribution (-Weibull), which
properly describes data when oxide thickness fluctuations are
present, in order to improve reliability assessment of ultra-thin oxides by
time-to-breakdown extrapolation and area scaling. The incorporation
of fluctuations allows a physical interpretation of the -Weibull
distribution in connection with the Tsallis statistics. In support to our
results, we analyze data of SiO-based MOS devices obtained
experimentally and theoretically through a percolation model, demonstrating an
advantageous description of the dielectric breakdown by the -Weibull
distribution.Comment: 5 pages, 3 figure
Dynamics of tournaments: the soccer case
A random walk-like model is considered to discuss statistical aspects of
tournaments. The model is applied to soccer leagues with emphasis on the
scores. This competitive system was computationally simulated and the results
are compared with empirical data from the English, the German and the Spanish
leagues and showed a good agreement with them. The present approach enabled us
to characterize a diffusion where the scores are not normally distributed,
having a short and asymmetric tail extending towards more positive values. We
argue that this non-Gaussian behavior is related with the difference between
the teams and with the asymmetry of the scores system. In addition, we compared
two tournament systems: the all-play-all and the elimination tournaments.Comment: To appear in EPJ
Path Integral Approach to the Nonextensive Canonical Density Matrix
Feynman's path integral is herein generalized to the nonextensive canonical
density matrix based on Tsallis entropy. This generalization is done in two
ways by using unnormalized and normalized constraints. Firstly, we consider the
path integral formulation with unnormalized constraints, and this
generalization is worked out through two different ways, which are shown to be
equivalent. These formulations with unnormalized constraints are solutions to
two generalized Bloch equations proposed in this work. The first form of the
generalized Bloch equation is linear, but with a temperature-dependent
effective Hamiltonian; the second form is nonlinear and resembles the anomalous
correlated diffusion equation (porous medium equation). Furthermore, we can
extend these results to the prescription of field theory using integral
representations. The second development is dedicated to analyzing the path
integral formulation with normalized constraints.
To illustrate the methods introduced here, we analyze the free particle case
and a non-interacting scalar field. The results herein obtained are expected to
be useful in the discussion of generic nonextensive contexts.Comment: (Univ. Est. de Maringa, PR- Brazil),17 pages, Late
Integrating expertises and ambitions for data-driven digital building permits - the EUNET4DBP
The digitalization of the process for building permit (involving the use of 3D information systems) is seen as a priority in a wide part of the world. Since it is a very multidisciplinary use case, involving a variety of stakeholders tackling complex issues and topics, some of them joined their efforts and skills in the European Network for Digital Building Permit. The initial activity of the network, after a review of on-going experiences, was a workshop to share knowledge about the topics involved and to identify the main ambitions of the network with respect to three pillars (i.e. Process - Rules and Requirements - Technology) and the related requirements. It was achieved through a collective brainstorming activity guided by digital tools, whose results were further analysed in a post-processing phase. Such results are presented in this paper and will be the base for planning the future network activity. © Authors 2020
Remarks on expansion and factorization approximation in the Tsallis nonextensive statistical mechanics
The validity of (1-q) expansion and factorization approximations are analysed
in the framework of Tsallis statistics. We employ exact expressions for
classical independent systems (harmonic oscillators) by considering the
unnormalized and normalized constrainsts. We show that these approxiamtions can
not be accurate in the analysis of systems with many degrees of freedom.Comment: Latex, 6 pages, 2 figure