We construct asymptotic formulae for the approximation of certain prolate spheroidal wave functions and of the corresponding eigenvalues. We investigate two regimes: when the ratio c/m decays, and when both c and m grow, but the ratio c/m stays bounded. Both the regions of validity and the accuracies of the obtained expansions are illustrated with numerical examples. © 2006 Elsevier Inc. All ri...

Active vibration control is investigated for axially moving strings with a tersioner. The tensioner is used as an actuator. The active control law is proposed from the view of the traveling wave propagation. Transverse response of both the uncontrolled and the controlled systems is derived in the frequency domain. The designed controller is numerically tested for the string under impulse and ha...

This paper analyzes the edge-reflection problem of obliquely incident guided waves in a plate. The generalized guided-wave theories in a plate, including the orthogonality of modes and the mode-decomposition method are summarized. The edge-reflection problem is solved on the basis of the mode-decomposition method. Some numerical results are presented and compared to experimental results. [doi:1...

The propagation of surface waves in a fluid- saturated porous isotropic layer over a semi-infinite homogeneous elastic medium with an irregularity for free and rigid interfaces have been studied. The rectangular irregularity has been taken in the half-space. The dispersion equation for Love waves is derived by simple mathematical techniques followed by Fourier transformations.  It can be seen t...