  Stochastic Resonance (SR) and Coherence Resonance (CR) have been studied
experimentally in the discharge plasma close to a homoclinic bifurcation. For
the SR phenomena, it is observed that a superimposed subthreshold periodic
signal can be recovered via stochastic modulations of the discharge voltage.
Furthermore, it is realized that even in the absence of a subthreshold
deterministic signal, the system dynamics can be recovered and optimized using
noise. This effect is defined as CR in the literature. In the present
experiments, induction of SR and CR are quantified using the Absolute Mean
Difference (AMD) and Normalized Variance (NV) techniques respectively. AMD is a
new statistical tool to quantify regularity in the stochastic resonance and is
independent of lag.
