用这个小程序可以解杜芬方程，可以通过相图判断混沌状态，判断加入噪声和信号-With this little program can Xie Duffing equation to determine the phase diagram can be chaos, judge by adding noise and signal

介绍了改进谱减法的原理及算法。提出在信噪比(sNR)较低的情况下，根据语音短时能量和过零率，判断在无声 或有声期间是否偶然的噪声过高，从而设定合适的参数降低噪声。-Introduced an improved spectral subtraction principles and algorithms. Proposed signal to noise ratio (sNR) lower case, according to voice short-term energy and zero-cr

提取淹没在噪声中的周期信号要求自相关（以判断周期）和互相关（以恢复信号自身）-Extraction drowned in the noise requirements of a periodic signal autocorrelation (to determine the cycle) and cross-correlation (to restore the signal itself)