Results 21 to 30 of about 8,503,197 (295)

Application of Local Histogram Clipping Equalization Image Enhancement in Bearing Fault Diagnosis

IEEE Access, 2022
Aiming at the problem that the time-frequency image of bearing fault characteristics is relatively weak and difficult to identify. This paper presents a time-frequency analysis method of local maximum synchrosqueezing transform based on image enhancement.
Zhiqiang Zeng, Rui Zhang, Wenan Cai, Yanfeng Li   +3 more
doaj   +1 more source

Bivariate Instantaneous Frequency and Bandwidth [PDF]

IEEE Transactions on Signal Processing, 2010
The generalizations of instantaneous frequency and instantaneous bandwidth to a bivariate signal are derived. These are uniquely defined whether the signal is represented as a pair of real-valued signals, or as one analytic and one anti-analytic signal.
Jonathan M. Lilly, Sofia C. Olhede
openaire   +3 more sources

An Improved Multi-Ridge Extraction Method Based on Differential Synchro-Squeezing Wavelet Transform

IEEE Access, 2021
It is very important to accurately extract the instantaneous frequency (IF) of complex non-stationary signals, so the signal processing methods based on IF are widely used in engineering.
Yanfeng Li, Zhijian Wang, Tiansheng Zhao, Wanqing Song   +3 more
doaj   +1 more source

Window Functions With Minimum-Sidelobe Derivatives for Computing Instantaneous Frequency

IEEE Access, 2022
In the field of nonstationary signal analysis and processing, the short-time Fourier transform (STFT) is frequently used to convert signals into the time-frequency domain.
Tsubasa Kusano, Kohei Yatabe, Yasuhiro Oikawa   +2 more
doaj   +1 more source

A Novel Strategy for Signal Denoising Using Two-Layer SVD and Its Application to Rub-Impact Fault Diagnosis of Aeroengine

Applied Sciences, 2022
The rub-impact fault, which occurs in the aeroengine, can cause frequency modulation (FM) in its vibration signal. Oscillated instantaneous frequency (IF) is a phenomenon of such a modulation mode, which carries critical fault information from the ...
Peng Zhang, Shunming Li, Kun Xu, Siqi Gong, Keyi Zhan, Maoxian Shen, Jun Tian, Xin Yuan   +7 more
doaj   +1 more source

Using Differential Geometry to Revisit the Paradoxes of the Instantaneous Frequency

IEEE Open Access Journal of Power and Energy, 2022
This paper proposes a general framework to interpret the concept of Instantaneous Frequency (IF) in three-phase systems. The paper first recalls the conventional frequency-domain analysis based on the Fourier transform as well as the definition of IF ...
Federico Milano, Georgios Tzounas, Ioannis Dassios, Mohammed Ahsan Adib Murad, Taulant Kerci   +4 more
doaj   +1 more source

Parameterized Instantaneous Frequency Estimation Method for Vibration Signal with Nonlinear Frequency Modulation

Machines, 2022
The vibration signal from the rotatory machinery condition monitoring under time-varying speed is usually amplitude-modulated (AM) and frequency-modulated (FM).
Yuexin Huang, Qiukun Zhang, Jianfeng Zhong, Zhixiong Chen, Shuncong Zhong   +4 more
doaj   +1 more source

A combination of genetic inversion and seismic frequency attributes to delineate reservoir targets in offshore northern Orange Basin, South Africa

Open Geosciences, 2020
The reported occurrence of Albian- and Cenomanian-aged braided fluvio-deltaic channels in the Orange Basin, South Africa, opens a window of exploration activities to characterize these channels as they are renowned to form some of the world’s giant oil ...
Samakinde Chris Adesola, van Bever Donker Jan Marinus, Fadipe Oluwaseun Adejuwon   +2 more
doaj   +1 more source

Use of the Cross Wigner-Ville Distribution for Estimation of Instantaneous Frequency [PDF]

, 1993
This correspondence presents an iterative instantaneous frequency (IF) estimation scheme in which successive IF estimates are obtained from the peak of the cross Wigner-Ville distribution (XWVD) using a reference signal synthesized from an initial IF ...
Oshea, P, Boashash, Boualem, Boashash, B, O'Shea, Peter J.   +3 more
core   +1 more source

On an instantaneous frequency estimator with FIR filters having maximally flat frequency response error magnitude

, 2001
In this paper an instantaneous frequency estimator (IFE) of a discrete-time base band complex signal is considered. The IFE is built around one-band, maximally flat linear-phase FIR filters, which are used for differentiating and delaying Cartesian ...
Cain, G.D., Tarczynski, A., Rojewski, M., Hermanowicz, E.   +3 more
core   +1 more source