Stochastic Resonance in a Coupled Array Without Periodic Driving

We manifest a stochastic resonance in a two-dimensional square array of coupled oscillators subjected only to white noise and constant driving forces.The result shows that the coherent output of every single oscillator plays the role of periodic input to its neighbours.Even without periodic driving,the cooperation of the white noise and the coupling can also result in the array enhanced stochastic resonance effect.In our investigation,global as well as local noise perturbation is taken into account.     

Stability analysis of delayed cellular neural networks with and without noise perturbation

The stability of a class of delayed cellular neural networks (DCNN) with or without noise perturbation is studied.After presenting a simple and easily checkable condition for the global exponential stability of a deterministic system,we further investigate the case with noise perturbation.When DCNN is perturbed by external noise,the system is globally stable.An important fact is that,when the system is perturbed by internal noise,it is globally exponentially stable only if the total noise strength is within a certain bound.This is significant since the stochastic resonance phenomena have been found to exist in many nonlinear systems.     

Mean Mobility and Rotation Number in Time-inhomogenous Brownian Ratchets

Recently, Brownian ratchets have attracted considerable attention due to their ability to realize a unidirectional transport only through the use of a proper asymmetry and thermal noise fluctuation, for recent review, see [1,2]. A general model which exhibits such a noise-induced transport (called ratchet effect) is the following overdamped one-dimensional pulsating ratchet system     

有噪及无噪的时滞细胞神经网络稳定性分析

分析了一类时滞细胞神经网络(DCNN)系统在无噪声和有噪声干扰情况下的稳定性．首先针对确定性系统给出了一种简单且容易验证的全局指数稳定性条件,然后讨论了噪声干扰下系统的稳定性．当DCNN被外部噪声扰动时,系统是全局稳定的．重要的是,当系统被内在噪声扰动时,只要噪声总强度控制在一定范围内,系统是全局指数稳定的．鉴于随机共振现象在越来越多的非线性生物系统中被发现,这种稳定性具有重要意义．     

Frequency Resonance in Stochastic Systems

The phenomenon of frequency resonance,which is usually related to deterministic systems.is investigated in stochastic systems.We show that for those autonomous systems driven only by white noise,if the output power spectrum exhibits a nonzero peak frequency,then applying a periodic signal just on this noise-induced central frequency can also induce a resonance phenomenon,which we call the frequency stochastic resonance.The effect of such a resonance in a coupled stochastic system is shown to be much better than that in a single-oscillator system.     

Stochastic Resonance and Ratchets： Two Closely Related Phenomena in Brownian Motors

Ratchet effect as well as the phenomenon of stochastic resonance (SR) is investigated in a simple flashing ratchet model. Numerical simulations show that both the power spectrum amplitude and the mean mobility of the system vary non-monotonically in similar manners with increasing the noise intensity and both reach their highest point nearly at the same noise level. We point out that the consistency of these two phenomena are just due to the existence of circular flux in non-equilibrium state.