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1.
Stochastic resonance in linear system driven by multiplicative noise and additive quadratic noise
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In this paper the stochastic resonance (SR) is studied in an overdamped linear system
driven by multiplicative noise and additive quadratic noise. The exact
expressions are obtained for the first two moments and the correlation
function by using linear response and the properties of the dichotomous noise.
SR phenomenon exhibits in the linear system. There are three different forms
of SR: the bona fide SR, the conventional SR and SR in the broad sense.
Moreover, the effect of the asymmetry of the multiplicative noise on the
signal-to-noise ratio (SNR) is different from that of the additive noise and
the effect of multiplicative noise and additive noise on SNR is different. 相似文献
2.
It is shown that, in spite of claims put forward in the literature, the stochastic resonance (SR) appears even in linear systems—both overdamped and inertial—driven by Gaussian white noise, and even after averaging the asymptotics over the initial phase of the input signal. This supports recent suggestions that SR is a universal effect present in every stochastic process modulated by external signals. It is also shown that the noise may sustain the output signal which otherwise would vanish exponentially in the course of time. 相似文献
3.
Stochastic resonance in an asymmetric bistable system driven by coloured correlated multiplicative and additive noise
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This paper investigates the stochastic resonance (SR) phenomenon in an asymmetric system with coupling between multiplicative and additive noise when the coupling between two noise terms is coloured. The approximate expression of signal-to-noise ratio has been obtained by applying the two-state theory and SR exhibits in the bistable system. Moreover, the potential asymmetry r and cross-correlation strength λ can weaken the SR phenomenon, while the cross-correlation time r can strengthen the SR phenomenon. 相似文献
4.
Stochastic resonance (SR) in an over-damped linear system subjected to an excitation of bias signal modulated noise with multiplicative and additive noises is investigated. We obtain the exact expressions of the first two moments and the signal-to-noise ratio (SNR) of the output by using linear-response theory. The SNR depends non-monotonically on the intensity and the correlation time of multiplicative noise, the correlation time of additive noise, the intensity of the cross noise between multiplicative and additive noise, as well as the external field frequency. The conventional SR, the SR in a broad sense and the bona fide SR are found in the system. The influences of the asymmetries of multiplicative and additive noise, the correlation rate of the cross noise, the intensity of additive noise, the amplitude of signal and the bias on the SNR are analyzed. Moreover, we pointed out that SR can be realized by tuning the system parameter with fixed noise, i.e., parameter-induced stochastic resonance (PSR) exists. 相似文献
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6.
We investigate stochastic resonance (SR) in the
FitzHugh--Nagumo system under combined bounded noise and weak
harmonic excitation. Taking a spectral amplification factor as a
signal-to-noise ratio, we show numerically that bounded noise can
induce SR by adjusting either the intensity of bounded noise or its
colour. Moreover, the increase of noise colour can enhance the SR
and make the peak of the SR shift toward lower noise intensities, which
is more feasible in practice. Since bounded noise is flexible to
model random excitation, these findings may have some potential
applications in engineering, neuroscience and biology. 相似文献
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通过将广义Langevin方程中的系统内噪声建模为分数阶高斯噪声,推导出分数阶Langevin方程, 其分数阶导数项阶数由系统内噪声的Hurst指数所确定.讨论了处于强噪声环境下的线性过阻尼分数阶 Langevin方程在周期信号激励下的共振行为,利用Shapiro-Loginov公式和Laplace变换, 推导了系统响应的一、二阶稳态矩和稳态响应振幅、方差的解析表达式.分析表明,适当参数下, 系统稳态响应振幅和方差随噪声的某些特征参数、周期激励信号的频率及系统部分参数的变化出现了 广义的随机共振现象. 相似文献
9.
Stochastic resonance (SR) is based on the cooperative effect between
the stochastic dynamical system and the external forcing. As is well
known, the cooperative effect is produced by adding noises. In this
paper, we show the evidence that by changing the system parameters
and the signal intensity, a nonlinear system in the presence of an
input aperiodic signal can yield the cooperative effect, with the
noise fixed. To quantify the nonlinear system output, we determine
the theoretical bit error rate (BER). By numerical simulation, the
validity of the theoretical derivation is checked. Besides, we show
that parameter-induced SR is more realizable than SR via adding
noises, especially when the noise intensity exceeds the resonance
level, or when the characteristic of the noise is not known. 相似文献
10.
研究了乘性非高斯噪声和加性高斯白噪声共同激励下非对称双稳系统的平均首次穿越时间和随机共振问题. 利用路径积分法和两态模型理论,推导出平均首次穿越时间和信噪比的表达式. 研究结果表明:势阱非对称性对两个不同方向的平均首次穿越时间的影响是不同的. 信噪比是加性噪声强度和势阱非对称性的非单调函数,系统出现了随机共振现象;信噪比是乘性噪声强度的单调函数,没有共振峰出现. 这说明该系统中乘性噪声强度和加性噪声强度对信噪比的影响是不同的.
关键词:
非高斯噪声
非对称双稳系统
平均首次穿越时间
随机共振 相似文献
11.
Stochastic resonance in a bistable system with coloured correlation between additive and multiplicative noise
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The phenomenon of stochastic resonance (SR) in a bistable nonlinear system with coupling between additive and multiplicative noises is investigated when the correlation between two noise terms is coloured. It is found that the signal-to-noise ratio (SNR) of the system is affected not only by the coupling strength λ between two noise terms, but also by the noise correlation time τ. The SNR is changed from a single peak, to two peaks with a dip, and then to a monotonically decreasing function with noise strength. The dependence of the SR on the initial conditions is entirely caused by the coupling strength λ between two noise terms. 相似文献
12.
较之于线性噪声, 非线性噪声更广泛地存在于实际系统中, 但其研究远不能满足实际情况的需要. 针对作为非线性阻尼涨落噪声基本构成成分的二次阻尼涨落噪声, 本文考虑了周期信号与之共同作用下的线性谐振子, 关注这类具有基本意义的阻尼涨落噪声的非线性对系统共振行为的影响. 利用Shapiro-Loginov公式和Laplace变换推导了系统稳态响应振幅的解析表达式, 并分析了稳态响应振幅的共振行为, 且以数值仿真验证了理论分析的有效性. 研究发现: 系统稳态响应振幅关于非线性阻尼涨落噪声系数具有非单调依赖关系, 特别是非线性阻尼涨落噪声比线性阻尼涨落噪声更有助于增强系统对外部周期信号的响应程度; 而且, 非线性阻尼涨落噪声比线性阻尼涨落噪声使得稳态响应振幅关于噪声强度具有更为丰富的共振行为; 同时, 二次阻尼涨落噪声使得稳态响应振幅关于系统频率出现真正的共振现象; 而在这些现象和性质中, 非线性噪声项的非线性性质对共振行为起着关键的作用. 显然, 以二次阻尼涨落作为基本形式引入的非线性阻尼涨落噪声, 可以有助于提高微弱周期信号检测的灵敏度和实现对周期信号的频率估计. 相似文献
13.
LUO Xiang-Dong GUO Feng ZHOU Yu-Rong 《理论物理通讯》2009,51(2):283-286
The phenomenon of stochastic resonance (SR) in an asymmetric mono-stable system subject to two external periodic forces and multiplicative and additive noise is investigated. It is shown that the signal-to-noise ratio (SNR) for the fundamental and higher harmonics is a non-monotonic function of the intensities of the multiplicative and additive noise, as well as of the system parameter. Moreover, the SNR for the fundamental harmonic decreases with the increase of the system asymmetry, while the SNR for the higher harmonics behaves non-monotonically as the system asymmetry varies. 相似文献
14.
We study the effects of noise intensity fluctuations on the stationary and dynamical properties of an overdamped Langevin model with a bistable potential and external periodical driving force. We calculated the stationary distributions, mean-first passage time (MFPT) and the spectral amplification factor using a complete set expansion (CSE) technique. We found resonant activation (RA) and stochastic resonance (SR) phenomena in the system under investigation. Moreover, the strength of RA and SR phenomena exhibit non-monotonic behavior and their trade-off relation as a function of the squared variation coefficient of the noise intensity process. The reliability of CSE is verified with Monte Carlo simulations. 相似文献
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HAN Yin-Xia LI Jing-Hui CHEN Shi-Gang 《理论物理通讯》2005,44(2):226-230
The phenomenon of stochastic resonance (SR) in a bistable nonlinear system is studied when the system is driven by the asymmetric potential and additive Gaussian colored noise. Using the unified colored noise approximation method, the additive Gaussian colored noise can be simplified to additive Gaussian white noise. The signal-to-noise ratio (SNR) is calculated according to the generalized two-state theory (shown in [H.S. Wio and S. Bouzat, Brazilian J.Phys. 29 (1999) 136]). We find that the SNR increases with the proximity of a to zero. In addition, the correlation time T between the additive Gaussian colored noise is also an ingredient to improve SR. The shorter the correlation time T between the Gaussian additive colored noise is, the higher of the peak value of SNR. 相似文献
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19.
M. Asfaw B. Aragie M. Bekele 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,79(3):371-376
We investigate the dynamics of impurities walking along a semiconductor layer assisted by thermal noise of strength D and external harmonic potential V(x). Applying a nonhomogeneous hot temperature in the vicinity of the potential minimum may modify the external potential into
a bistable effective potential.
We propose the ways of mobilizing and eradicating
the unwanted impurities along the semiconductor
layer. Furthermore, the thermally activated rate of hopping for the impurities as a function of the model parameters is studied
in high barrier limit.
Via two state approximation, we also study the stochastic resonance (SR) of the impurities dynamics where the same noise source
that induces the
dynamics also induces the transition from mono-stable to bistable state which leads to SR in the presence of time varying
field. 相似文献