A Feature Extraction Method for the Wear of Milling Tools Based on the Hilbert Marginal Spectrum

2019 ◽  
Vol 23 (6) ◽  
pp. 847-868 ◽  
Author(s):  
Xu Chuangwen ◽  
Chai Yuzhen ◽  
Li Huaiyuan ◽  
Shi Zhicheng ◽  
Zhang Ling ◽  
...  
2012 ◽  
Vol 201-202 ◽  
pp. 255-258 ◽  
Author(s):  
Jian Wu Wang ◽  
Feng Zou

In the paper, a fault feature extraction method for rotor system is proposed based on Hilbert marginal spectrum. Compared with the spectrum analysis method via Fourier transformation, it is more effective for the rotating machinery vibrating signal analysis. Extracting the rotor system fault feature frequency from Hilbert marginal spectrum can not only enhance the frequency resolution, but also remove other unrelated frequency component, so as to make the spectrum peak of the fault feature frequency more obviously, and the analysis diagnosis results more accurately. This method result is applied to the fault feature extraction and diagnosis of the rotor system, and the analysis results of the experiment signal verify the validity of this method.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2322
Author(s):  
Abdenour Soualhi ◽  
Bilal El Yousfi ◽  
Hubert Razik ◽  
Tianzhen Wang

This paper presents an innovative approach to the extraction of an indicator for the monitoring of bearing degradation. This approach is based on the principles of the empirical mode decomposition (EMD) and the Hilbert transform (HT). The proposed approach extracts the temporal components of oscillating vibration signals called intrinsic mode functions (IMFs). These components are classified locally from the highest frequencies to the lowest frequencies. By selecting the appropriate components, it is possible to construct a bank of self-adaptive and automatic filters. Combined with the HT, the EMD allows an estimate of the instantaneous frequency of each IMF. A health indicator called the Hilbert marginal spectrum density is then extracted in order to detect and diagnose the degradation of bearings. This approach was validated on two test benches with variable speeds and loads. The obtained results demonstrated the effectiveness of this approach for the monitoring of ball and roller bearings.


2020 ◽  
Vol 27 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Xuan Xiao ◽  
Wei-Jie Chen ◽  
Wang-Ren Qiu

Background: The information of quaternary structure attributes of proteins is very important because it is closely related to the biological functions of proteins. With the rapid development of new generation sequencing technology, we are facing a challenge: how to automatically identify the four-level attributes of new polypeptide chains according to their sequence information (i.e., whether they are formed as just as a monomer, or as a hetero-oligomer, or a homo-oligomer). Objective: In this article, our goal is to find a new way to represent protein sequences, thereby improving the prediction rate of protein quaternary structure. Methods: In this article, we developed a prediction system for protein quaternary structural type in which a protein sequence was expressed by combining the Pfam functional-domain and gene ontology. turn protein features into digital sequences, and complete the prediction of quaternary structure through specific machine learning algorithms and verification algorithm. Results: Our data set contains 5495 protein samples. Through the method provided in this paper, we classify proteins into monomer, or as a hetero-oligomer, or a homo-oligomer, and the prediction rate is 74.38%, which is 3.24% higher than that of previous studies. Through this new feature extraction method, we can further classify the four-level structure of proteins, and the results are also correspondingly improved. Conclusion: After the applying the new prediction system, compared with the previous results, we have successfully improved the prediction rate. We have reason to believe that the feature extraction method in this paper has better practicability and can be used as a reference for other protein classification problems.


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