852919.fig.001a
(a)
852919.fig.001b
(b)
852919.fig.001c
(c)
852919.fig.001d
(d)
Figure 1: Plots of the Duffing-van der pol equation: (a) RK4, (b) Chandrasekar et al. [15], (c) present method, and (d) DTM [16].