When the nonlinearity of a system matches with its input signal and its input noise, the additivity of the noise would not decrease the system output signal-to-noise ratio (SNR); on the contrary, it can greatly improve the SNR of the system, i.e., there exists an optimum input noise intensity which enables the SNR reaches its maximum value. The above phenomenon is called stochastic resonance (SR). The SR in a broad sense means the non-monotonic behavior of the output signal (output signal-to-no...