(a) The results of for N = 1024, α = 1.0, and different ε. From right to left, the curves are for ε = 0.005, 0.007, 0.01, and 0.02, respectively. For all cases, V_n are chosen randomly from the interval (0.5, 1.5) and the lowest 10% of frequency modes are initially excited. (b) The curve of ε = 0.007 is kept fixed. The other curves are rescaled as the time is divided by a suitable factor so that they superpose at .