ARtract-We have presented techniques [ 11 [ 6 ] based on linear prediction (LP) and singular value decomposition (SVD) for accurate estimation of closely spaced frequencies of sinusoidal signals in noise. In this note we extend these techniques to estimate the parameters of exponentially damped sinusoidal signals in noise. The estimation procedure presented here makes use of "backward predictio...

PURPOSE To introduce a new model describing human in vivo corneal deswelling after hypoxic contact lens wear, based on a damped harmonic oscillator, which can describe an overshoot in corneal deswelling, to compare this new model with the currently used exponential model, and also to test whether a diurnal variation in baseline corneal thickness exists that would have to be taken into considera...

Alfvén wave propagation, reflection, and heating of the chromosphere are studied for a one-dimensional solar atmosphere by self-consistently solving plasma, neutral fluid, and Maxwell’s equations with incorporation of the Hall effect and strong electron–neutral, electron–ion, and ion–neutral collisions. We have developed a numerical model based on an implicit backward difference formula of seco...

This paper describes the physical relationships that exist between the Fourier transform and the response spectrum of a strong-motion accelerogram. By developing the new concept of the "Damped Fourier Spectrum" (D.F.S.), we show that the velocity and displacement of the damped oscillator can be represented by a linear combination of the real and imaginary parts of the D.F.S. and by the initial ...

This study investigates whether a flexible pole can be used as an energy-saving method for humans carrying loads. We model the carrier and pole system as a driven damped harmonic oscillator and predict that the energy expended by the carrier is affected by the compliance of the pole and the ratio between the pole's natural frequency and the carrier's step frequency. We tested the model by measu...

Asymptotic expansions as e--,0 that are uniformly valid in t are obtained for the membrane's motion and the scattered acoustic pressure field. The small parameter ß is the density ratio of the acoustic fluid and the membrane. For simplicity of presentation, only plane, compact incident pulses are considered. The scattered field depends on the pulse's tructure. If it is a sufficiently narrow ban...

In this paper, the method of electric analog synthesis is applied to design a piezo-electro-mechanical arch able show capacity multimodal damping. An electric-analog circuit designed by using finite number lumped elements representing equivalent curved beam. Spatial and frequency coherence conditions are proven be verified for modes damped: in fact, lumped-element can damp only vibration modes....

The propagation of classical waves in the presence of a disordered medium is studied. We consider wave pulses containing a broad range of frequencies in terms of the configurationally averaged Green function of the system. Damped oscillations in the time-dependent response trailing behind the direct arrival of the pulse (coda) are predicted, the periods of which are governed by the density of s...

Model updating concerns the modification of an existing but inaccurate model with measured data. For models characterized by quadratic pencils, the measured data usually involve incomplete knowledge of natural frequencies, mode shapes, or other spectral information. In conducting the updating, it is often desirable to match only the part of observed data without tampering with the other part of...

In this paper we study the linearized Vlasov--Poisson equation for localized disturbances of an infinite, homogeneous Maxwellian background distribution in $\mathbb{R}^3_x \times \mathbb{R}^3_v$. contrast to confined case $\mathbb{T}^d_x \mathbb{R}_v^d$, or unconfined $\mathbb{R}^d_x \mathbb{R}^d_v$ with screening, dynamics disturbance are not scattering towards free transport as $t \to \pm \in...