According to the fact that high frequency will be abnormally attenuated when seismic signals travel across reservoirs, a new method, which is named high-precision time-frequency entropy based on synchrosqueezing generalized S-transform, is proposed for hydrocarbon reservoir detection in this paper. First, the proposed method obtains the time-frequency spectra by synchrosqueezing generalized S-transform (SSGST), which are concentrated around the real instantaneous frequency of the signals. Then, considering the characteristics and effects of noises, we give a frequency constraint condition to calculate the entropy based on time-frequency spectra. The synthetic example verifies that the entropy will be abnormally high when seismic signals have an abnormal attenuation. Besides, comparing with the GST time-frequency entropy and the original SSGST time-frequency entropy in field data, the results of the proposed method show higher precision. Moreover, the proposed method can not only accurately detect and locate hydrocarbon reservoirs, but also effectively suppress the impact of random noises.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7512946 | PMC |
http://dx.doi.org/10.3390/e20060428 | DOI Listing |
Sensors (Basel)
December 2024
College of Railway Transportation, Hunan University of Technology, Zhuzhou 412007, China.
Rail corrugation intensifies wheel-rail vibrations, often leading to damage in vehicle-track system components within affected sections. This paper proposes a novel method for identifying rail corrugation, which combines Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN), permutation entropy (PE), and Smoothed Pseudo Wigner-Ville Distribution (SPWVD). Initially, vertical acceleration data from the axle box are decomposed using CEEMDAN to extract intrinsic mode functions (IMFs) with distinct frequencies.
View Article and Find Full Text PDFSci Rep
December 2024
College of Mechanical Engineering, Beihua University, Jilin City, Jilin, 132021, China.
To address the limitations of weak information extraction of rolling bearing fault features and the poor generalization performance of diagnostic methods, a novel method was proposed based on sparrow search algorithm (SSA)-Variational Mode Decomposition (VMD) and refined composite multi-scale dispersion entropy (RCMDE). Firstly, SSA optimized the key parameters of VMD to decompose the fault signal. The time-frequency domain comprehensive evaluation factor algorithm was then employed to select the sensitive intrinsic mode function (IMF) components for reconstruction.
View Article and Find Full Text PDFBrain Sci
November 2024
Research Field of Medical Instruments and Bioinformation Processing, College of Instrumentation and Electrical Engineering, Jilin University, No. 938 West Democracy Street, Changchun 130061, China.
Objectives: Brain-behavior connections are a new means to evaluate sports performance. This electroencephalogram (EEG) study aims to estimate endurance exercise performance by investigating eigenvalue trends and comparing their sensitivity and linearity.
Methods: Twenty-three cross-country skiers completed endurance cycling tasks.
Math Biosci Eng
August 2024
Department of Nursing, The Third Affiliated Hospital with Nanjing Medical University, Changzhou 213003, China.
It is important to classify electroencephalography (EEG) signals automatically for the diagnosis and treatment of epilepsy. Currently, the dominant single-modal feature extraction methods cannot cover the information of different modalities, resulting in poor classification performance of existing methods, especially the multi-classification problem. We proposed a multi-modal feature fusion (MMFF) method for epileptic EEG signals.
View Article and Find Full Text PDFSheng Wu Yi Xue Gong Cheng Xue Za Zhi
October 2024
Rehabilitation Medical Department, Tianjin Union Medical Center, Tianjin 300121, P. R. China.
Ischemic stroke often leads to cognitive dysfunction, which delays the recovery process of patients. However, its pathogenesis is not yet clear. In this study, the cerebral ischemia-reperfusion model was built as the experimental object, and the hippocampal dentate gyrus (DG) was the target brain area.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!