57 On the Prediction in Time Domain of Ship Non-Stationary Swaying Motions Available to Purchase

The nonstationarity of real-life ship swaying motions is tested through the qualitative method combined with the quantitative method. A prediction method based on EMD is proposed to deal with the nonlinearity and nonstationarity of ship swaying motions, that is, Firstly, Empirical Mode Decomposition (EMD) is applied to decompose the ship swaying time series into some smooth and simple intrinsic mode functions (IMFs); then RBFNN is applied to each IMF prediction; lastly, all IMFs' prediction results are reconstructed to compose the final result. Prediction results show that the method based on EMD-RBFNN can improve the precision effectively, especially on the ship non-stationary swaying motions.