We examine statistical properties of a daily hot pixel time series recorded in Brazil during the period 1998–2006, using Multifractal Detrended Fluctuation Analysis (MF-DFA). We find that generalized scaling exponent h(q) is a decreasing function of q, indicating multifractal behavior of hot...

We study the statistical properties of hourly wind speed time series detected at four weather stations in the state of Pernambuco, Brazil, in the period 2008–2009. We find that the average and maximum hourly wind speeds deviate from a mutual linear relationship, and that they may be well...

In this work an application of MCMC is proposed for unsupervised data classification, in conjunction with a novel pairwise objective function, which is shown to work well in situations where clusters to be identified have a strong overlap, and the centroid oriented methods (such as K-means) fail...

In this work we present the first exact solution of a system of interacting particles with phase transitions of order higher than two. The presented analytical derivation shows that the Ising model on the Cayley tree exhibits a line of third order phase transition points, between temperatures...

While the Ising model on the Cayley tree has no spontaneous magnetization at nonzero temperatures in the thermodynamic limit, we show that finite systems of astronomical sizes remain magnetically ordered in a wide temperature range, if the symmetry is broken by fixing an arbitrary single (bulk...

It is found that the zero field susceptibility χ of the Ising model on the Cayley tree exhibits unusually weak divergence at the critical point TC. The susceptibility amplitude is found to diverge at TC proportionally to the tree generation level n, while the behavior of χ is otherwise...

We present a novel approach to pattern recognition, based on mapping of images onto a multidimensional parameter space defined by a long range interaction Ising model Hamiltonian. It is shown that different character patterns occupy mutually distant points within the n-dimensional space defined...

We describe a geometric approach for studying phase transitions, based upon the analysis of the “density of states” (DOS) functions (exact partition functions) for finite Ising systems. This approach presents a complementary method to the standard Monte Carlo method, since with a single...