Cyclically Shifted Extreme-point Symmetric Mode Decomposition (CS-ESMD)-based Progressive Denoising Approach for Ground-based Synthetic Aperture Radar Bridge Health Monitoring Signals

Abstract

Ground-based synthetic aperture radar (GB-SAR) has a wide range of applications in bridge health detection by monitoring dynamic deflection data. However, the collected dynamic deflection signals are easily subjected to interference by noises during GB-SAR monitoring due to ground motion and complex traffic factors. It is also difficult to accurately eliminate the influence of noises by using the traditional modal decomposition method. Therefore, we propose a cyclically shifted extreme-point symmetric mode decomposition (CS-ESMD)-based progressive denoising approach, which can accurately identify high/low-frequency noise information from dynamic deflection signals through a progressive process. First, CS-ESMD is used to construct virtual multi-channel signals for the following progressive denoising process. Second, ESMD is performed on multi-channel dynamic deflection data to separate useful and high-frequency noise information. Finally, the low-frequency noises and the residual highfrequency noises are further identified and removed by second-order blind identification (SOBI) and the fast Fourier transform (FFT) method. Through simulation and practical experiments, we show that the accuracy of the progressive denoising method can be increased by 37.2% compared with traditional methods, which shows its effectiveness in improving the precision of GB-SAR dynamic deflection signals.

Ferrielectricity in the Archetypal Antiferroelectric, PbZrO3

“…It is noteworthy that compared to the above ferroelectric‐based compositions, antiferroelectric‐like materials have lower dielectric loss, do not require pre‐poling, and do not suffer from thermal, electrical or stress depoling that largely limit the functional range of ferroelectric materials in electromechanical applications. [ 31,32 ] Additionally, the very high electromechanical response in our PbZrO 3 thin films is obtained in samples processed via simple, low‐cost chemical solution deposition rather than epitaxially grown on expensive substrates by complex tools requiring resource‐intensive (ultra)high vacuum. The superior electromechanical response and simple, low‐cost preparation method make these PbZrO 3 thin films a competitive and promising material for applications in nano‐electromechanical devices.…”