Severity: Warning
Message: fopen(/var/lib/php/sessions/ci_session23401dcdp41s8ausvcdsiqckhsptv7no): Failed to open stream: No space left on device
Filename: drivers/Session_files_driver.php
Line Number: 177
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Severity: Warning
Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)
Filename: Session/Session.php
Line Number: 137
Backtrace:
File: /var/www/html/index.php
Line: 316
Function: require_once
Rotation of an elastic medium gives rise to a shift of frequency of its acoustic modes, i.e., the time-period vibrations that exist in it. This frequency shift is investigated by applying perturbation theory in the regime of small ratios of the rotation velocity and the frequency of the acoustic mode. In an expansion of the relative frequency shift in powers of this ratio, upper bounds are derived for the first-order and the second-order terms. The derivation of the theoretical upper bounds of the first-order term is presented for linear vibration modes as well as for stable nonlinear vibrations with periodic time dependence that can be represented by a Fourier series.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.3693646 | DOI Listing |
Physicians evaluate a patient's respiratory health during a physical examination by visual assessment of the work of breathing (WoB) to determine respiratory stability, and by detecting abnormal lung sounds via lung auscultation using a stethoscope to identify common pathological lung diseases, such as chronic obstructive pulmonary disease (COPD) and pneumonia. Since these assessment methods are subjective, a low-profile device used for an accurate and quantitative monitoring approach could provide valuable preemptive insights into respiratory health, proving to be clinically beneficial. To achieve this goal, we have developed a miniature patch consisting of a sensitive wideband multi-axis seismometer that can be placed on the anatomical areas of a patient's lungs to enable an effective quantification of a patient's WoB and lung sounds.
View Article and Find Full Text PDFSci Rep
March 2025
Faculty of Integrated Circuit, Xidian University, Xi'an, 710071, Shaanxi, China.
Focused high-frequency acoustic waves are utilized in industrial non-destructive testing (NDT) on account of their exceptional spatial resolution and high sensitivity. However, the majority of the focusing methods currently adopted for high-frequency transducers are mechanical pressure focusing and lens focusing, which may inflict mechanical damage on piezoelectric elements and give rise to low transmission efficiency. In this paper, an efficient approach to achieving self-focusing at high frequency is proposed.
View Article and Find Full Text PDFHear Res
March 2025
Hearing Systems Section, Department of Health Technology, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
Acoustic amplitude modulation (AM) patterns carry important information, particularly in speech. AM masking, influenced by frequency selectivity in the modulation domain, is considered a crucial factor for speech intelligibility in noisy environments. Based on recent evidence suggesting an age-related decline in AM frequency selectivity, this study investigated whether increased AM masking in older listeners is associated with reduced speech intelligibility.
View Article and Find Full Text PDFThe interaction between surface acoustic waves (SAWs) and magnons is an interesting phenomenon that can be used to control spins in spintronic devices, and thus the visualization of the related spatiotemporal dynamics can be useful. In this study, we used dual-frequency-comb-based asynchronous optical sampling to record the spatiotemporal evolution of the surface vibration associated with an optically excited SAW and that of the spin precession associated with the magnon under the same excitation condition at effectively 160 frames/ns. Isotropic and anisotropic propagation were observed for phonons and magnons, respectively, demonstrating the capability of measuring such dynamics with high resolution.
View Article and Find Full Text PDFAlzheimers Dement
February 2025
Department of Medicine, Boston University Chobanian and Avedisian School of Medicine, Boston, Massachusetts, USA.
Introduction: Digital voice analysis is an emerging tool for differentiating cognitive states, but it poses privacy risks as automated systems may inadvertently identify speakers.
Methods: We developed a computational framework to evaluate the trade-off between voice obfuscation and cognitive assessment accuracy, using pitch-shifting as a representative method. This framework was applied to voice recordings from the Framingham Heart Study (FHS, n = 128) and the DementiaBank Delaware (DBD, n = 85) corpus, both featuring responses to neuropsychological tests.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!