correlation function analysis meaning in English

Time - field analysis , frequency - field analysis and correlation function analysis in traditional , have been improved in application of fault diagnosis . and gray system , obscure subjection degree , expert system , wavelet analysis and neural network , etc . have been applied in running state of qualitative analysis system , however , it is the issue having been concerned all along in academic circle that the fault state of system is analyzed quantitatively
传统的时域分析、频域分析和相关函数分析在故障诊断应用中得到了不断的改进，灰色关联度、模糊隶属度、专家系统、小波分析及神经网络等方法在定性分析系统的运动状态中得到广泛的应用，而定量地分析系统的故障状态是学术界一直关注的问题。