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P. F. Gora

Publications and source records attributed to P. F. Gora.

11 recordsLinked to original sources
arXiv2024

Stochastic models of memristive behavior

Under normal operations, memristive devices undergo variability in time and space and have internal dynamics. Interplay of memory and stochastic signal processing in memristive devices makes them candidates for performing bio-inspired tasks of information transduction and transformation, where intrinsic random behavior can be harnessed for high performance of circuits built up of individual memory storing elements. The paper discusses models of single memristive devices exhibiting both - dynamic hysteresis and Stochastic Resonance, addressing also the cooperative effect of correlated noises acting on the system and occurrence of dirty hysteretic rounding.

cs.ET↗
arXiv2007

Chaos in Newtonian iterations: Searching for zeros which are not there

We show analytically that Newtonian iterations, when applied to a polynomial equation, have a positive topological entropy. In a specific example of an attempt to ``find'' the real solutions of the equation $x^2+1=0$, we show that the Newton method is chaotic. We analytically find the invariant density and show how this problem relates to that of a piecewise linear map.

nlin.CD↗
arXiv2006

An exactly solvable nonlinear model: Constructive effects of correlations between Gaussian noises

A system with two correlated Gaussian white noises is analysed. This system can describe both stochastic localization and long tails in the stationary distribution. Correlations between the noises can lead to a nonmonotonic behaviour of the variance as function of the intensity of one of the noises and to a stochastic resonance. A method for improving the transmission of external periodic signal by tuning parameters of the system discussed in this paper is proposed.

cond-mat.stat-mech↗
arXiv2005

Stationary distributions of a noisy logistic process

Stationary solutions to a Fokker-Planck equation corresponding to a noisy logistic equation with correlated Gaussian white noises are constructed. Stationary distributions exist even if the corresponding deterministic system displays an unlimited growth. Positive correlations between the noises can lead to a minimum of the variance of the process and to the stochastic resonance if the system is additionally driven by a periodic signal.

cond-mat.stat-mech↗
arXiv2004

Linear transmitter with correlated noises

A linear transmitter with correlated Gaussian white additive and multiplicative noises and a periodic signal coupled either additively or multiplicatively is considered. The correlations have a weak destructive effect in case of the additive signal and a strong constructive effect in case of the multiplicative one. Analytical results for the linear transmitter with the additive signal agree with those obtained previously by a different approach. We also show how to analytically calculate certain expectation values involving exponentials of Gaussian processes.

cond-mat.stat-mech↗
arXiv2004

Population explosion suppressed by noise: Stationary distributions and how to simulate them

We show that two dynamical systems exhibiting very different deterministic behaviours possess very similar stationary distributions when stabilized by a multiplicative Gaussian white noise. We also discuss practical aspects of numerically simulating these systems. We show that there exists a noise level that is optimal in the sense that the interval during which discrete-time versions of the systems remain physical is maximized. Analytical results are illustrated by numerical examples.

cond-mat.stat-mech↗
arXiv2003

Array enhanced stochastic resonance and spatially correlated noises

We discuss the role of spatial correlations of the noise in the array enhanced stochastic resonance. We show numerically that the noises with negative correlations between different sites lead to significantly larger values of the signal-to-noise ratio than the uncorrelated noises or noises with positive correlations. If the noise is global, the system displays only the conventional stochastic resonance, without any array enhancement.

cond-mat.stat-mech↗
arXiv2001

$1/f$ noise in chemical reactions

A chemical system consisting of two species, one of which evolves deterministically and independently of the other, which in turn is driven by the dynamics of the former and by an additional multiplicative Gaussian white noise, displays a $1/f$ noise for intermediate to large frequencies. A novel mechanism responsible for the $1/f$ noise is suggested.

cond-mat.stat-mech↗