计算声发射时域信号特征值：裕值，振幅因子FK、fc，峭度，-Calculation of acoustic emission time-domain signal characteristic values: margin value, the amplitude factor FK, fc, kurtosis,

进行纯净信号和加噪信号的时频域显示，及其包络图显示，并计算加噪信号的信噪比、互相关系数、峭度值，对信号进行离散余弦变换。(The time-frequency domain display of pure signal and noise-added signal and its envelope diagram display are carried out, and the signal-to-noise ratio, correlation coefficient and kurtosis