Biomedical subjects

HS Wio

Publications and source records attributed to HS Wio.

18 recordsLinked to original sources

PubMed2000

Enhancement of stochastic resonance in distributed systems due to a selective coupling

Recent massive numerical simulations have shown that the response of a "stochastic resonator" is enhanced as a consequence of spatial coupling. Similar results have been analytically obtained in a reaction-diffusion model, using nonequilibrium potential techniques. We now consider a field-dependent diffusivity and show that the selectivity of the coupling is more efficient for achieving stochastic-resonance enhancement than its overall value in the constant-diffusivity case.

Journal Article↗

PubMed2000

Anomalous diffusion with absorption: exact time-dependent solutions

Recently, analytical solutions of a nonlinear Fokker-Planck equation describing anomalous diffusion with an external linear force were found using a nonextensive thermostatistical Ansatz. We have extended these solutions to the case when an homogeneous absorption process is also present. Some peculiar aspects of the interrelation between the deterministic force, the nonlinear diffusion, and the absorption process are discussed.

Journal Article↗

PubMed2000

Nonequilibrium phase transitions induced by multiplicative noise: effects of self-correlation

A recently introduced lattice model, describing an extended system which exhibits a reentrant (symmetry-breaking, second-order) noise-induced nonequilibrium phase transition, is studied under the assumption that the multiplicative noise leading to the transition is colored. Within an effective Markovian approximation and a mean-field scheme it is found that when the self-correlation time tau of the noise is different from zero, the transition is also reentrant with respect to the spatial coupling D. In other words, at variance with what one expects for equilibrium phase transitions, a large enough value of D favors disorder. Moreover, except for a small region in the parameter subspace determined by the noise intensity sigma and D, an increase in tau usually prevents the formation of an ordered state. These effects are supported by numerical simulations.

Journal Article↗

PubMed2000

Stochastic resonance driven by time-modulated correlated white noise sources

We analyze the effects caused by the simultaneous presence of correlated additive and multiplicative noises for stochastic resonance. Besides the standard potential modulation we also consider a time-periodic variation of the correlation between the two noise sources. As a foremost result we find that stochastic resonance, as characterized by the signal-to-noise ratio and the spectral amplification, becomes characteristically broadened. The broadening can be controlled by varying the relative phase shift between the two types of modulation force.

Journal Article↗

PubMed1996