Atrial flutter and atrial tachycardia detection using Bayesian approach with high resolution time–frequency spectrum from ECG recordings

2013 ◽  
Vol 8 (6) ◽  
pp. 992-999 ◽  
Author(s):  
Jinseok Lee ◽  
David D. McManus ◽  
Peter Bourrell ◽  
Leif Sörnmo ◽  
Ki H. Chon
Keyword(s):  
High Resolution ◽  
Atrial Flutter ◽  
Frequency Spectrum ◽  
Bayesian Approach ◽  
Atrial Tachycardia ◽  
Resolution Time ◽  
Time Frequency

scholarly journals High-Resolution Time-Frequency Spectrum-Based Lung Function Test from a Smartphone Microphone

Sensors ◽  
2016 ◽  
Vol 16 (8) ◽  
pp. 1305 ◽  
Author(s):  
Tharoeun Thap ◽  
Heewon Chung ◽  
Changwon Jeong ◽  
Ki-Eun Hwang ◽  
Hak-Ryul Kim ◽  
...  
Keyword(s):  
High Resolution ◽  
Lung Function ◽  
Frequency Spectrum ◽  
Lung Function Test ◽  
Resolution Time ◽  
Time Frequency ◽  
Function Test

Detecting Karst Voids Based on Dominant Frequencies of Seismic Profiles

2021 ◽  
Author(s):  
Ying Rao ◽  
Yongxin Guo ◽  
Duo Xu
Keyword(s):  
High Resolution ◽  
Frequency Spectrum ◽  
High Speed ◽  
Dominant Frequency ◽  
Frequency Function ◽  
Resolution Time ◽  
High Speed Rail ◽  
Karst Terrain ◽  
Near Surface ◽  
Time Frequency

AbstractThe presence of near-surface karst voids is an extremely difficult issue in the construction of a high-speed rail (HSR) foundation. Seismic constant-offset profile (COP) method is one of the shallow geophysics technologies which may be used for the detection of karst voids. Although a COP image does not directly reveal the characters related to the anomalies in a karst terrain, the dominant frequency of the COP image in a karst terrain is significantly lower than the dominant frequency over the background without karstification or voids. This dominant-frequency anomaly is due to the strong attenuation effect when seismic waves propagate through any karst voids. Thus, we propose using the dominant-frequency anomalies of the COP image to directly detect near-surface karst voids in a karst terrain. First, we generate a high-resolution time–frequency spectrum for each COP trace, using the modified Wigner-Ville distribution (WVD) algorithm which combines WVD with a multichannel maximum entropy method. Second, we estimate a high-precision dominant-frequency function which varies along the reflection time, based on the corresponding high-resolution time–frequency spectrum. Finally, we detect the geological anomalies by analyzing low-frequency distributions in the dominant-frequency image for all traces. We demonstrate this procedure with a case study for the detection of karst voids within the high-speed rail foundation in a karst terrain, and verify the interpretation of hidden voids, cavities, clays and peats directly with drilling cores.

Rayleigh wave separation using high‐resolution time‐frequency polarization filter

2020 ◽  
Vol 68 (7) ◽  
pp. 2104-2118
Author(s):  
Mohsen Kazemnia Kakhki ◽  
Webe J. Mansur ◽  
Franciane C. Peters
Keyword(s):  
High Resolution ◽  
Rayleigh Wave ◽  
Resolution Time ◽  
Polarization Filter ◽  
Time Frequency ◽  
Wave Separation

High resolution time-frequency representation for chirp signals using an adaptive system based on duffing oscillators

2016 ◽  
Vol 55 ◽  
pp. 32-43 ◽  
Author(s):  
Antonio H. Costa ◽  
Rogerio Enríquez-Caldera ◽  
Maribel Tello-Bello ◽  
Carlos R. Bermúdez-Gómez
Keyword(s):  
High Resolution ◽  
Adaptive System ◽  
Resolution Time ◽  
Time Frequency ◽  
Frequency Representation ◽  
Chirp Signals
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