Evolutionally processes of 1/f fluctuation generated with higher order correlation

The 1/f fluctuation is generally generated in the complex system composed of dissipative and non dissipative partial system. If the 1/f fluctuation is related to nonequilibrium system, the higher order non-Gaussian processes may be concerned with its generation. In the present paper, different types of 1/f fluctuation generated by computer simulations are investigated on the view point of higher order correlation function and time reversibility. We have found using the 4th order correlation function that there exists the difference in the absolute value of the time reversibility. It is concluded from the above fact that several types of the 1/f fluctuations exist although they have the same 1/f spectra.