提出了一种结合经验模态分解（EMD）和自适应短时傅里叶变换（STFT）的铁路货车滚动轴承故障诊断方法。

In this paper, a freight car rolling element bearings fault diagnosis method based on Empirical Mode Decomposition(EMD) and adaptive short_time Fourier transform(STFT) is proposed.

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短时傅里叶变换技术存在窗口问题，限制了垂向分辨率，而且不能适应地层厚度的变化；

STFT method has the window problem, which limits the vertical resolution, and cannot adapt the thickness transverse change of layers.

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此外，DFT，这通常是由于FFT实现，或快速傅里叶变换，你可能还想阅读有关的STFT(短时傅里叶变换)。

In addition to the DFT, which is usually implemented as the FFT, or fast Fourier transform, you may also want to read about the STFT (short-time Fourier transform).

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