（８）铁科院冯庚斌等在１９９４年５月所著《机车车辆故障诊断技术》一书中指出，无量纲幅域诊断参数是从有量纲参数演化得到的，其取值是决定于信号幅值的概率密度函数的性质或形状。他们选择了五个常用无量纲参数，进行了三种不同工况的试验，证明波形指标几乎不具诊断能力 (8) In an article entitled “Technology of Fault Diagnosis of Rolling Stock and Vehicle” issued by Ironclad Academy Feng Gengbin et al. In May 1994, the dimensionless domain diagnostic parameters are evolved from dimensionless parameters, and the value depends on the signal The nature or shape of the probability density function of amplitude. They selected five commonly used dimensionless numbers and conducted experiments in three different conditions to prove that the waveform indicators were barely diagnostic