The functional form representation of input-output relationship through Volterra series provides a structured mathematical platform for the study of nonlinear systems. It employs multi-dimensional kernels, which upon convolution with the applied excitation forces, express system response in the form of a power series. Frequency domain transforms of these multi-dimensional kernels provide higher...

The harmonic oscillator is one of the most fundamental systems in quantum mechanics. Equipped with its solution—one of the first that every physics student learns to calculate exactly—it is possible to describe realistic problems, from phonons in a crystal to the interaction of light with an atom. It is perhaps ironic, then, how challenging it is to actually prepare a pure harmonic oscillator s...

This study measured difference limens for fundamental frequency (DLF0s) for a target harmonic complex in the presence of a simultaneous spectrally overlapping harmonic masker. The resolvability of the target harmonics was manipulated by bandpass filtering the stimuli into a low (800-2400 Hz) or high (1600-3200 Hz) spectral region, using different nominal F0s for the targets (100, 200, and 400 H...

The nonlinear three-wave interaction process at the heart of the parametric decay process is studied by launching counter-propagating Alfv en waves from antennas placed at either end of the Large Plasma Device [W. Gekelman et al., Rev. Sci. Instrum. 62, 2875 (1991)]. A resonance in the beat wave response produced by the two launched Alfv en waves is observed and is identified as a damped ion ac...

The presentation concerns a method of wavemorphing applied to a model of the phonatory excitation, the instantaneous frequency and the harmonic richness of which are controlled. This method is based on an interpolation between the Fourier coefficients of two template waveforms. The method enables morphing continuously from one waveshape to another. Possible applications are the simulation of di...

This work is devoted to fast and parameter-robust iterative solvers for frequency domain finite element equations, approximating the eddy current problem with harmonic excitation. We construct a preconditioned MinRes solver for the frequency domain equations, that is robust (= parameter– independent) in both the discretization parameter h and the frequency ω.

This paper describes a new simulation technique of nonlinear RF circuits driven by modulated signals. Based on a true mixed-mode algorithm, it allows time-domain transient analysis of the envelope, while handling the carrier behavior in frequency-domain. Being similar in scope to the previously reported Envelope Transient Harmonic Balance [1]-[3], it is not limited, though, in excitation bandwi...

Optical investigation of movable microsystem components using time-averaged holography is investigated in this paper. It is shown that even a harmonic excitation of a non-linear microsystem may result in an unpredictable chaotic motion. Analytical results between parameters of the chaotic oscillations and the formation of time-averaged fringes provide a deeper insight into computational and exp...

The accuracy of excited states calculated with Kohn-Sham density functional theory using the maximum overlap method has been assessed for the calculation of adiabatic excitation energies, excited state structures, and excited state harmonic and anharmonic vibrational frequencies for open-shell singlet excited states. The computed Kohn-Sham adiabatic excitation energies are improved significantl...