Stochastic resonance in time-delayed asymmetric bistable systems driven by modulation signal
Stochastic resonance(SR)belongs to a typical phenomenon of the constructive role of random noises.Under certain conditions,the response of system changes non-monotonically with the noise intensity,that is,SR occurs.In many studies on the SR of bistable systems,the potential function is usually symmetric.However,the potential function is asymmetric in many situations.In comparison to the symmetric bistable systems,the asymmetric bistable systems are expected to produce more and stronger dynamical behaviors.In this paper,we investigate the SR of time-delayed asymmetric bistable systems driven by modulation signal.By using the theory of small delay approximation,the effective potential function and steady-state probability density of the system are firstly deduced and the effect of system parameters on the effective potential well is analyzed.Then,by using the adiabatic approximation theory,the mean first pass time(MFPT)and signal-to-noise ratio(SNR)of the system are obtained,which are two common evaluation indicators for SR.Fi-nally,the influence of signal amplitude,time delay and time-delay intensity on the MFPT and SNR are ex-plored.It is shown that the signal amplitude and time delay can enhance the SR,while the time-delay inten-sity can firstly suppress and then promote the occurrence of SR.Here we point that,from the point of control-ling SR,adjusting the asymmetry of potential is more efficient than adjusting the time delay.This result is ab-sent in previous reports at the presence of modulation signal.
国家科技期刊平台
NSTL
万方数据
