tokens: Note that the following abbreviations are used for Fourier Transform ( FT ) , Short Time Frequency Transform ( STFT ) , Wavelet Transform ( WT ) , Empirical Mode Decomposition ( EMD ) , Auto - regression ( AR ) , Hilbert - Huang Transform ( HHT ) , Neural Network ( NN ) , Hidden Markov Modeling ( HMM ) , Support Vector Machine ( SVM ) , Genetic Algorithm ( GA ) , Auto - regressive Moving Average ( ARMA ) , Principal Component Analysis ( PCA),Wigner - Ville Transforms ( WVT ) , Support Vector Regression ( SVR ) .