7Huang N E, Wu M L, Long S R, et al. The empirical mode decomposition and the Hilbert spectrum for non linear and nonstationary time series analysis[C]//Proceedings of the Royal Society London. [S. l.]: [s.n.], 1998: 903-995.
8Delechelle E, Lemoine J, Niang O. Empirical mode decomposition: an analytical approach for sifting process[J]. IEEE Signal Processing Letters, 2005, 12(11): 764-767.
