The Study Of Dynamic Behavior In A Bistable System Driven By Harmonic Noise

Here,stochastic bistable systems subject to the harmonic noise was investi-gated.First in the Chapter 1,we introduced research background and research status of nonlinear behavior of electrical systems,stochastic resonance,noise enhanced stability and coherence resonance respectively.Then the relevant s-tochastic theory and the research methods are also introducted.Finally,effects of dynamic behaviors of the bistable system subjects to the harmonic noise was investigated,the results are shown as follows:The Chapter 3,the bistable system driven by the harmonic noise and a small periodic signal was investigated,and the results indicate that:(1)As pa-rameter Γ of the harmonic noise is fixed,we found that the noise intensity D and the harmonic noise parameter Ω can affect quality factor β of the power spectrum.The greater of β,the more obviously of stochastic resonance(SR)phenomenon.In addition,the peak of β go along the positive direction of Ωwith the increment of the noise intensity.(2)With fixed the parameter Ω of the harmonic noise,the SR phenomenon can also be obtained by adjusting the pa-rameter Γ at different values of noise intensity D.(3)Furthermore,adjustment of D,Γ and Ω make the SR of the system be controlled.Then we consid-ered the system driven by two correlated harmonic noise,and noise enhanced stability phenomenon was investigated.The numerical simulation results show that:(1)As Ω is fixed,average residence time(T)always exists peak as Γ in-creasing,i.e.,noise enhanced stability phenomenon.And with the increment of parameter Γ,the peak of(T)towards the direction of the multiplicative noise intensity Q increase moving.(2)Similarly,for the fixed Γ,the peak of(T)moves toward the positive direction of Q axis with the incrementof Ω,.This means that the harmonic noise plays a key role on controlling of SR and noise enhanced stability.In the Chapter 4,the bistable system driven by a harmonic noise in the absence of periodic signal was investigated,the numerical results show that:(1)The characteristic correlation time A of the system as a function of Ω exhibits a maximal value,i.e.,coherence resonance(CR).And with the increment of Γ,the peak of the curve goes towards the positive direction of Ω axis.(2)In the same way,the curve of A vs Γ with fixed D appears a peak too,and the CR phenomenon can also be controlled by adjusting value of Ω.This means that the harmonic noise plays a key role on controlling of CR too.