[1] HUANG N E.The empirical mode decomposition and the hilbert spectrum for nonlinear and nonstationary time series analysis[J].Procedures of the Royal Society of London,1998,A454(3):903-995.
[2] HUANG N E,SHEN Z,LONG S R.A new view of nonlinear water waves:the hilbert spectrum[J].Annu Rev Fluid Mech,1999,31:417-457.