Two-dimensional decaying turbulence is simulated using the lattice Boltzmann method with the Bhatnagar-Gross-Krook collision operator. The simulation results are analyzed in the spectral space and the auto power spectral density functions of the one-particle distribution functions are presented. It is shown that both the equilibrium and the non-equilibrium parts of the distribution functions ha...

Earlier we proposed the stochastic point process model, which reproduces a variety of self-affine time series exhibiting power spectral density S(f) scaling as power of the frequency f and derived a stochastic differential equation with the same long range memory properties. Here we present a stochastic differential equation as a dynamical model of the observed memory in the financial time seri...

Miguel A. Lagunas Antoni Gasull Procesado de Sefial en Comunicaciones E.T.S:.I. Telecomunicacidn. Apdo. 30002 Barcelona, Spain. Starting from the classical procedure reported by Capon for power level estinietion from ML filters, the authors present how this method can be modifyed in order to obtain a power spectral density estimate. The basic idea is to compute the effective bandwidth of the ML...

A simple analytically solvable model exhibiting a 1/f spectrum in an arbitrarily wide frequency range was recently proposed by Kaulakys and Meškauskas (KM). Signals consisting of a sequence of pulses show that inherent origin of the 1/f noise is Brownian fluctuations of the average intervent time between subsequent pulses of the pulse sequence. We generalize the KM model to reproduce the variet...

In this work, we present a method for early forest fire detection from a satellite image using the power spectral density of a Gaussian white noise. To obtain the latter, we have considered each satellite image matrix line as a realization of a non stationary random process in the Thermal Infra-Red (TIR) spectral band, and then divided each line into very small intervals in which any random pro...

We explore the behavior of the fractal-shot-noise driven doubly stochastic Poisson point process or FSNDP, for which the associated impulse response functions assume a decaying power-law form. For a variety of parameters of the process, we obtain expressions for the count number distribution and moments, Fano factor, normalized coincidence rate, power spectral density, and time probability dens...

We probe the scale dependence of the primordial spectrum in the light of the three-year WMAP (WMAP3) alone and WMAP3 in combination with the other cosmological observations such as galaxy clustering and Type Ia Supernova (SNIa). We pay particular attention to the combination with the Lyman α (Lyα) forest. Different from the first-year WMAP (WMAP1), WMAP3’s preference on the running of the scala...

The efficiency with which spectrum is used in wireless communications systems is becoming increasingly important as a result of the expected growth in traffic demand and the finite nature of usable spectrum. Spectral efficiency, defined as throughput divided by bandwidth, is a useful metric for evaluating the use of spectrum in wireless systems. In any given area the achievable spectrum efficie...

the renewable energy resources such as wind power have recently attracted more researchers’ attention. it is mainly due to the aggressive energy consumption, high pollution and cost of fossil fuels. in this era, the future fluctuations of these time series should be predicted to increase the reliability of the power network. in this paper, the dynamic characteristics and short-term predictabili...

A theoretical framework for analysis of speech enhancement algorithms is introduced for performance assessment of spectral subtraction type of methods. The quality of the enhanced speech is related to physical quantities of the speech and noise (such as stationarity time and spectral flatness), as well as to design variables of the noise suppressor. The derived theoretical results are compared ...