satisfying: (i) a(¢) = 0; (ii) a(B) 3 0 for all B G IF, and (iii) u(UkBk) : Eku(Bk) with .... 56 ~â cgr ââ klx + k3x3 : A cos(o)t + W) + n(t) (7a) and ..... ons (0.0, 0.0), (b) 1st, (c) 2nd, ((1) 4th, (6) 18th, and (f) 20th cycle of forcing period, ... class of nonlinear stochastic systems with either asymptotic density behavior can be reï¬ected.