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1.
E. Heinsalu M. Patriarca F. Marchesoni 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):19-22
We study the effects of the confining conditions on the
occurrence of stochastic resonance (SR) in continuous bistable
systems. We model such systems by means of double-well potentials
that diverge like |x|q for |x|↦∞. For super-harmonic
(hard) potentials with q > 2 the SR peak sharpens with increasing q, whereas for sub-harmonic (soft) potentials, q < 2, it
gets
suppressed. 相似文献
2.
Y.-C. Lai K. Park L. Rajagopalan 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):65-70
We investigate a class of nonlinear wave equations subject to
periodic forcing and noise, and address the issue of energy optimization.
Numerically, we use a pseudo-spectral method to solve the nonlinear stochastic
partial differential equation and compute the energy of the system as a
function of the driving amplitude in the presence of noise.
In the fairly general setting where the system possesses two coexisting
states, one with low and another with high energy, noise can induce
intermittent switchings between the two states. A striking finding is that,
for fixed noise, the system energy can be optimized by the driving in a
form of resonance. The phenomenon can be explained by the Langevin dynamics
of particle motion in a double-well potential system with symmetry breaking.
The finding can have applications to small-size devices such as
microelectromechanical resonators and to waves in fluid and plasma. 相似文献
3.
Yong Woon Parc Duk-Su Koh Wokyung Sung 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):127-131
Stochastic resonance (SR) is a novel cooperative phenomenon occurring in
nonlinear systems due to coupling of an ambient noise and an external
signal. Biological systems may use SR mechanism to detect the signal
efficiently from an external environment. A number of studies have addressed
the SR in artificial ion channels considering external voltages as noises.
More important than these external noises is the internal, thermal noise
which changes the channel conformations essential for biological functions.
In this work, we consider that the channel gating rates follow a
non-Arrhenius temperature dependence derived from experimental data of a
real biological channel. Using the Monte-Carlo simulations, we find that in
this channel SR occurs near a physiological temperature in a very
distinctive manner compared with that for the Arrhenius gating model. 相似文献
4.
5.
T. Prager A. B. Neiman L. Schimansky-Geier 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,72(1):119-126
Stimulation with periodic force is a standard method to
study response properties of a system. Here we examine a special
type of systems which generate a sequence of events with
uncorrelated time intervals. We review analytical tools to calculate
the gain and the signal-to-noise ratio for such systems when
perturbed by sinusoidal signal and then apply these tools to the
stochastic FitzHugh-Nagumo model. 相似文献
6.
A. Fiasconaro W. Ebeling E. Gudowska-Nowak 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,65(3):403-414
We give an overview over recent studies on the model of Active Brownian Motion (ABM) coupled to reservoirs providing free
energy which may be converted into kinetic energy of motion. First, we present an introduction to a general concept of active
Brownian particles which are capable to take up energy from the source and transform part of it in order to perform various
activities. In the second part of our presentation we consider applications of ABM to ratchet systems with different forms
of differentiable potentials. Both analytical and numerical evaluations are discussed for three cases of sinusoidal, staircaselike
and Mateos ratchet potentials, also with the additional loads modelled by tilted potential structure. In addition, stochastic
character of the kinetics is investigated by considering perturbation by Gaussian white noise which is shown to be responsible
for driving the directionality of the asymptotic flux in the ratchet. This stochastically driven directionality effect is visualized as a strong nonmonotonic dependence of the statistics of the right versus left trajectories of motion
leading to a net current of particles. Possible applications of the ratchet systems to molecular motors are also briefly discussed. 相似文献
7.
A. A. Koronovskii A. E. Hramov 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,62(4):447-452
We consider a type of intermittent behavior that occurs
as the result of the interplay between dynamical mechanisms giving
rise to type-II intermittency and random dynamics. We analytically
deduce the law for the distribution of the laminar phases, which has
never been obtained hitherto. The already known dependence of the
mean length of the laminar phases on the criticality parameter [Phys. Rev. E
68, 036203 (2003)] follows as a corollary of the carried out
research. We also prove that this dependence obtained earlier under
the assumption of the fixed form of the reinjection probability does
not depend on the relaminarization properties, and, correspondingly,
the obtained expression of the mean length of the laminar phases on
the criticality parameter remains
correct for different types of the reinjection probability. 相似文献
8.
A. Shabunin A. Efimov 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,65(3):387-393
A spatio-temporal process in the Lattice Lotka Volterra (LLV) model, when realized on low dimensional support, is studied.
It is shown that the introduction of a long-range mixing causes a drastic change in the system’s behavior, which transits
from small random-like fluctuations to global oscillations when the mixing rate transcends above a critical point. The amplitude
of the induced oscillations is well defined by the mixing rate and is insensitive to the initial conditions and the lattice
size variations. The observed behavior essentially differs from that predicted by the Mean-Field model which is conservative.
The oscillations are of limit-cycle type and appear as a stochastic analog of a Hopf bifurcation. 相似文献
9.
10.
Y. Zhang G. Hu 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,3(2):253-256
The transient process of globally coupled bistable systems from an unstable state to metastable state (i.e, quenching process) is studied analytically for small noise intensity. The influences of noise intensity and system size
on the system evolution are investigated. The problem of a large number of coupled Langevin equations is reduced to a simple
problem of a one-dimensional ordinary differential equation, subject to a white noise with intensity explicitly given. The
analytical results are fully confirmed by direct numerical computations.
Received: 3 July 1997 / Revised: 4 December 1997 / Accepted: 15 January 1998 相似文献
11.
P. S.?Burada G.?Schmid D.?Reguera J. M.?Rubi P.?H?nggi 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):11-18
We demonstrate the existence of stochastic resonance (SR)
in confined systems arising from entropy variations associated to
the presence of irregular boundaries. When the motion of a Brownian
particle is constrained to a region with uneven boundaries, the
presence of a periodic input may give rise to a peak in the spectral
amplification factor and therefore to the appearance of the SR
phenomenon. We have proved that the amplification factor depends on
the shape of the region through which the particle moves and that by
adjusting its characteristic geometric parameters one may optimize
the response of the system. The situation in which the appearance of
such entropic stochastic resonance (ESR) occurs is common for
small-scale systems in which confinement and noise play an prominent
role. The novel mechanism found could thus constitute an important
tool for the characterization of these systems and can put to use
for controlling their basic properties. 相似文献
12.
We study the phenomenon of stochastic resonance on
small-world networks consisting of bistable genetic regulatory units,
whereby the external subthreshold periodic forcing is introduced as a
pacemaker trying to impose its rhythm on the whole network through the
single unit to which it is introduced. Without the addition of additive
spatiotemporal noise, however, the whole network remains forever trapped in
one of the two stable steady states of the local dynamics. We show that the
correlation between the frequency of subthreshold pacemaker activity and the
response of the network is resonantly dependent on the intensity of additive
noise. The reported pacemaker driven stochastic resonance depends
significantly on the asymmetry of the two potential wells characterizing the
bistable dynamics, which can be tuned via a single system parameter. In
particular, we show that the ratio between the clustering coefficient and
the characteristic path length is a suitable quantity defining the ability
of a small-world network to facilitate the outreach of the pacemaker-emitted
subthreshold rhythm, but only if the asymmetry between the potentials is
practically negligible. In case of substantially asymmetric potentials the
impact of the small-world topology is less profound and cannot warrant an
enhancement of stochastic resonance by units that are located far from the
pacemaker. 相似文献
13.
I.?Goychuk P.?H?nggi 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):29-35
In biological systems, information is frequentlytransferred with Poisson like spike processes (shot noise) modulatedin time by information-carrying signals. How then to quantifyinformation transfer by such processes for nonstationary inputsignals of finite duration? Is there some minimal length of theinput signal duration versus its strength? Can such signals bebetter detected when immersed in noise stemming from thesurroundings by increasing the stochastic intensity? These are somebasic questions which we attempt to address within an analyticaltheory based on the Kullback-Leibler information concept applied torandom processes. 相似文献
14.
When the processive motor protein kinesin walks along the biopolymer microtubule it can occasionally make a backward step.
Recent single molecule experiments on moving kinesin have revealed that the forward-to-backward step ratio decreases exponentially
with the load force. Carter and Cross (Nature 435, 308-312, 2005) found that this ratio tightly followed 802 × exp[−0.95F], where F is the load force in piconewtons. A straightforward analysis of a Brownian step leads to L/(2k
B
T) as the factor in front of the load force, where L is the 8 nm stepsize, k
B
is the Boltzmann constant, and T is the temperature. The factor L/(2k
B
T) does indeed equal 0.95 pN−1. The same analysis shows how the 802 prefactor derives from the power stroke energy G as exp[G/(2k
B
T)]. There are indications that the power stroke derives from the entropically driven coiling of the 30 amino acid neck linker
that connects the two kinesin heads. This idea is examined and consequences are deduced. 相似文献
15.
E. A. Calzetta 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,68(4):601-605
The thermal efficiency of the kinesin cycle at stalling is presently a matter of some debate, with published predictions ranging
from 0 [Phys. Rev. Lett. 99, 158102 (2007); Phys. Rev. E 78, 011915 (2008)] to 100% [in Molecular Motors, edited by M. Schliwa (Wiley-VCH Verlag GmbH, Weinheim (2003), p. 207]. In this note we attemp to clarify the issues involved.
We also find an upper bound on the kinesin efficiency by constructing an ideal kinesin cycle to which the real cycle may be compared. The ideal cycle has a thermal efficiency of less than one, and the real one is less
efficient than the ideal one always, in compliance with Carnot’s theorem. 相似文献
16.
Detecting and quantifying temporal correlations in stochastic resonance via information theory measures 总被引:1,自引:0,他引:1
O. A. Rosso C. Masoller 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):37-43
We show that Information Theory quantifiers are suitable tools for detecting and for quantifying noise-induced temporal correlations
in stochastic resonance phenomena. We use the Bandt & Pompe (BP) method [Phys. Rev. Lett. 88, 174102 (2002)] to define a probability distribution, P, that fully characterizes temporal correlations. The BP method is
based on a comparison of neighboring values, and here is applied to the temporal sequence of residence-time intervals generated
by the paradigmatic model of a Brownian particle in a sinusoidally modulated bistable potential. The probability distribution
P generated via the BP method has associated a normalized Shannon entropy, H[P], and a statistical complexity measure, C[P],
which is defined as proposed by Rosso et al. [Phys. Rev. Lett. 99, 154102 (2007)]. The statistical complexity quantifies not only randomness but also the presence of correlational structures,
the two extreme circumstances of maximum knowledge (“perfect order") and maximum ignorance (“complete randomness") being regarded
an “trivial", and in consequence, having complexity C = 0. We show that both, H and C, display resonant features as a function
of the noise intensity, i.e., for an optimal level of noise the entropy displays a minimum and the complexity, a maximum.
This resonant behavior indicates noise-enhanced temporal correlations in the sequence of residence-time intervals. The methodology
proposed here has great potential for the precise detection of subtle signatures of noise-induced temporal correlations in
real-world complex signals. 相似文献
17.
T. Dunn D. N. Guerra P. Mohanty 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):5-10
Stochastic resonance with white noise has been well established as a potential signal amplification mechanism in nanomechanical
two-state systems. While white noise represents the archetypal stimulus for stochastic resonance, typical operating environments
for nanomechanical devices often contain different classes of noise, particularly colored noise with a 1/f spectrum. As a
result, improved understanding of the effects of noise color will be helpful in maximizing device performance. Here we report
measurements of stochastic resonance in a silicon nanomechanical resonator using 1/f noise and Ornstein-Uhlenbeck noise types.
Power spectral densities and residence time distributions provide insight into asymmetry of the bistable amplitude states,
and the data sets suggest that 1/fα noise spectra with increasing noise color (i.e. α) may lead to increasing asymmetry in the system, reducing the achievable
amplification. Furthermore, we explore the effects of correlation time τ on stochastic resonance with the use of exponentially
correlated noise. We find monotonic suppression of the spectral amplification as the correlation time increases. 相似文献
18.
19.
S. Lahiri A. M. Jayannavar 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(1):87-92
We investigate the total entropy production of a Brownian particle in a driven bistable system. This system exhibits the phenomenon
of stochastic resonance. We show that in the time-periodic steady state, the probability density function for the total entropy
production satisfies Seifert’s integral and detailed fluctuation theorems over finite time trajectories. 相似文献
20.
Stochastic multiresonance in a bistable sawtooth potential driven by correlated multiplicative and additive noise 总被引:1,自引:0,他引:1
J. Wang L. Cao D.J. Wu 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,29(1):123-128
We present an analytic investigation of the signal-to-noise ratio (SNR) by studying the bistable sawtooth system driven by correlated Gaussian white noises. The analytic expression of SNR is obtained. Based on it, we detect the phenomenon of stochastic multiresonance, which arises from the dependence of SNR upon the noises correlation coefficient. Furthermore, there exists not only resonance, but also suppression in the SNR∼D (the additive noise intensity) curve and the SNR∼Q (the multiplicative noise intensity) curve.
Received 26 February 2002 / Received in final form 12 July 2002 Published online 17 September 2002 相似文献