The Doppler blood flow signal is inherently a nonstationary Gaussian random process whose time-frequency representation associates with the time-varying velocity of blood flow and its variations.
多普勒超声血流信号是一个非平稳的高斯随机过程，其时频分布与血流的速度及其变化有密切的关系。
2
The second nonstationary random process mathematical model, which is based on data, is the a modification to the first nonstationary random process mathematical model.
基于数据的第二种非平稳随机过程数学模型是第一种非平稳随机过程数学模型的继续。
3
An integral inference method for nonstationary stochastic process is established.