8Rai V K,Mohanty A R.Bearing Fault Diagnosis Using FFT of Intrinsic Mode Functions in Hilbert-Huang Ttransform[J].Mechanical Systems and Signal Processing,2007,21:2 607-2 615.
9Huang N E,Shen Z,Long S R.The Empirical Mode Decomposition and Hilbert Spectrum for Nonlinear and Nonstationary Time Series Analysis[J].Pro.Roy.Soc.London A,1998,454:903-995.