This paper analyzes statistical characteristics of underwater acoustic channels using experimental measurements. Channel impulse responses (CIRs) are estimated in the time domain using a least square method with sliding windows applied to received data. The probability density functions (PDF) of the real part, imaginary part, magnitude, and phase of the CIR are estimated, and the two-sample Kol...

The evolution of probability distribution functions (PDFs) of continuous density, velocity and velocity derivatives ( deformation tensor) fields in the theory of cosmological gravitational instability are considered. We show that in the Newtonian theory the dynamical equations cannot be reduced to the closed set of Lagrangian equations. Since continuous fields from galaxy surveys need sufficien...

A new and fast unsupervised technique for partitioning high resolution Synthetic Aperture Radar (SAR) images into homogeneous regions is proposed. This technique is based on Fisher probability density functions (PDF) of the pixel value fluctuations and on an image model that consists of a patchwork of homogeneous regions with polygonal boundaries. The partition is obtained by minimizing the sto...

In this paper, the performance analysis of an energy detector is exploited over composite multipath/shadowing fading channels, which is modeled by Rayleigh-lognormal (RL) distribution. Based on an approximate channel model which was recently proposed by the author, the RL envelope probability density function (pdf) is approximated by a finite sum of weighted Rayleigh pdfs. Relying on this inter...

The paper introduced a new method based on probability density function (PDF) and phase space diagram method for photoplethysmography (PPG) signal extracting. In the paper, PPG information was generated from human fingertips by smartphones. The pulse wave period was then separated and reconstructed into probability density function (PDF) by the phase space diagram algorithm. The difference betw...

We consider a class of spiking neuron models, defined by a set of conditions which are typical for basic threshold-type models like leaky integrate-and-fire, or binding neuron modela and also for some artificial neurons. A neuron is fed with a point renewal process. A relation between the three probability density functions (PDF): (i) PDF of input interspike intervals ISIs, (ii) PDF of output i...

The mean shift (MS) algorithm is a non-parametric, iterative technique that has been used to find modes of an estimated probability density function (pdf). Although the MS algorithm has been widely used in many applications, such as clustering, image segmentation, and object tracking, a rigorous proof for its convergence is still missing. This paper tries to fill some of the gaps between theory...

The probability distribution functions (PDF) of density of the interstellar medium (ISM) in galactic disks and global star formation rate are discussed. Three-dimensional hydrodynamic simulations show that the PDFs in globally stable, inhomogeneous ISM in galactic disks are well fitted by a single lognormal function over a wide density range. The dispersion of the log-normal PDF (LN-PDF) is lar...

Let us first define, for the random sequences X = [X1, . . . , Xn] and Y = [Y1 . . . , Yn] and their corresponding sequence realizations x = [x1, . . . , xn] and y = [y1 . . . , yn] where xk, yk ∈ R, the following probability density functions (pdfs): fX(x) ∆ = ∏n k=1 fX(xk) as the input pdf, fY |X(y|x) = ∏n k=1 fY |X(yk|xk) as the memoryless channel (transition) pdf, and fY (y) as the output p...

The Preisach formalism is used to model magnetic hysteresis loops in soft magnetic materials subject to tensile stress. The model uses the Stoner-Wohlfarth mechanism of coherent rotation and dispersion of easy axes to capture the vector response of the magnetization. The Preisach density is constructed as the weighed sum of normal probability density functions (pdf) for the regions of high and ...