Low frequency oscillation is an important attribute of human brain activity, and the amplitude low fluctuation (ALFF) effective method to reflect characteristics oscillation, which has been widely used in treatment diseases other fields. However, due accuracy current analysis methods for signal extraction ALFF, we propose Fourier-based synchrosqueezing transform (FSST), often field processing e...

A wealth of information about respiratory system is encoded in the airflow signal. While direct measurement via spirometer with an occlusive seal gold standard, this may not be practical for ambulatory monitoring patients. Advances sensor technology have made motion thorax and abdomen feasible small inexpensive devices, but estimating from these time series challenging due to presence complicat...

The gearbox is one of the key components in wind turbines. Gearbox fault signals are usually nonstationary and highly contaminated with noise. The presence of amplitude-modulated and frequency-modulated (AM-FM) characteristics compound the difficulty of precise fault diagnosis of wind turbines, therefore, it is crucial to develop an effective fault diagnosis method for such equipment. This pape...

Recently, the study of near- and below- threshold regime harmonics as a potential source of intense coherent vacuum-ultraviolet radiation has received considerable attention. However, the dynamical origin of these lower harmonics, particularly for the molecular systems, is less understood and largely unexplored. Here we perform the first fully ab initio and high precision 3D quantum study of th...

The empirical mode decomposition (EMD) is a powerful tool for non-stationary signal analysis. It has been used successfully for sound and vibration signals separation and time-frequency representation. Linear time-frequency analysis (TFA) is another powerful tool for non-stationary signal. Linear TFAs, e.g. short-time Fourier transform (STFT) and wavelet transform (WT), depend linearly upon the...

We study the real-time dynamics retrieval from a time series via the time-frequency (TF) analysis with the minimal latency guarantee. While different from the well-known intrinsic latency definition in the filter design, a rigorous definition of intrinsic latency for different time-frequency representations (TFR) is provided, including the short time Fourier transform (STFT), synchrosqeezing tr...

OBJECTIVE While extracting the temporal dynamical features based on the time-frequency analyses, like the reassignment and synchrosqueezing transform, attracts more and more interest in biomedical data analysis, we should be careful about artifacts generated by interpolation schemes, in particular when the sampling rate is not significantly higher than the frequency of the oscillatory component...

Near- and below-threshold harmonic generation provides a potential approach to generate vacuum-ultraviolet frequency comb. However, the dynamical origin of in these lower harmonics is less understood and largely unexplored. Here we perform an ab initio quantum study of the near- and below-threshold harmonic generation of caesium (Cs) atoms in an intense 3,600-nm mid-infrared laser field. Combin...