The article presents the methodology for finding material damping capacity at higher frequency and lower amplitudes. Lamb wave dispersion theory is used for finding the damping capacity of composite material which is used at extensively high frequency applications. The method has been implemented on carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) plates. The Lam...

Quantitative estimates of quality factor Q are useful for a variety of applications, ranging from seismic-acquisition design, to seismic processing, amplitude analysis, and reservoir characterization. However, Q model building, which is conventionally done in the data space using ray-based tomography, is a notoriously challenging problem due to issues like spectral interference, low signal-to-n...

Pulse wave analysis with computerized diagnosis was used for myocardial ischemia patients. Novel feature derived from form factor of pulse signal was investigated. Form factor is estimated from variance of pulse signal waveform. Pulse waves were measured using newly developed three-axis sphygmography. Three groups participated in this study: 16 patients diagnosed with myocardial ischemia (posit...

We comment on two issues in quantum cosmology, in the context of the Wheeler–De Witt equation and wave function of the Universe: (i) arrow of time and interpretation of the wave function in the classically allowed regions; (ii) stability of an approximation of the Born–Oppenheimer type in classically forbidden regions of the scale factor.

The design and implementation of an interpolator using wave digital filters is presented. The interpolator increases the sample frequency with a factor of 4, from 800 kHz to 3.2 MHz. The design approach yields implementations with low power consumption and small chip area. The excellent stability and sensitivity properties of wave digital filters are retained.

With a laser-excited acoustic wave as the carrier wave and by modulation of the light wavelength of a multikilohertz-repetition-rate optical parametric oscillator at a lower frequency than the acoustic frequency, we demonstrate a wavelength-amplitude double-modulation technique and achieve an enhancement factor of 35 in sensitivity in photoacoustic trace gas detection with the technique.