In order to detect grid harmonic and reactive current precisely and real time, this paper arrived at a method of harmonic and reactive current real-time detection applied to active power filter based on the three-phase circuit instantaneous reactive power theory. With Matlab simulation software, researches on simulation of harmonic detection means are carried out, and an analysis of the simulat...

In this work, we obtain a short-time existence result for harmonic map heat flow coupled with smooth family of complete metrics in the domain manifold. Our results generalize by Li-Tam (Invent Math 105(1):1–46, 1991) and Chen-Zhu (J Differ Geom 74:119–154, 2006). particular, prove along Ricci g(t) on M into manifold curvature bounded from above, under assumption: (i) $$|\text {Rm}(g(t))|\le a/t...

The paper considers the application of instantaneous harmonic analysis to a real-time vocal processing system for pitch, timbre and time-scale modifications. The analysis technique is based on narrow band filtering using special analysis filters with frequency-modulated impulse response. The main advantage of the technique is high accuracy of harmonic parameters estimation that provides adequat...

In this paper, modal analysis of the fluid-structure interaction has been investigated. Using classical laminated plate theory, a closed form solution for natural frequencies of FSI is extracted. For fluid, homogenous, inviscid and irrotational fluid flow is assumed. Then, a combined governing equation for the plate-fluid system is derived. In order to validate the equations and results, they a...

The propagator for a harmonic oscillator with general time-dependent mass and frequency matrices is constructed from the Van-Vleck/Morette formula. The explicit form of the classical action, and thus of the propagator, is found in terms of infinite series which are solutions to a set of differential equations. Those equations are found independently via the Hamilton-Jacobi equation, and by comp...

This paper concerns the reconstruction of the scattering coefficient in a two-dimensional transport equation from angularly averaged measurements when the probing source is isotropic and time-harmonic. This is a practical setting in the medical imaging modality called Optical Tomography. As the modulation frequency of the source increases, we show that the reconstruction of the scattering coeff...

We consider the angular averaging of solutions to time-harmonic transport equations. Such quantities model measurements obtained for instance in optical tomography, a medical imaging technique, with frequency-modulated sources. Frequency modulated sources are useful to separate ballistic photons from photons that undergo scattering with the underlying medium. This paper presents a precise asymp...

Numerical methods for the computation of harmonic propagation and distortion differ in the manner in which they represent the harmonic sources and the system impedance. Iterative methods (e.g. harmonic load flow) use a phasor representation of these parameters. Time domain methods, on the other hand, use a time representation of the system elements and the harmonic sources. Thus, they are gener...

We study the asymptotic behavior of the wave function in a simple one dimensional model of ionization by pulses, in which the time-dependent potential is of the form V (x, t) = −2δ(x)(1 − e cosωt), where δ is the Dirac distribution. We find the ionization probability in the limit t → ∞ for all λ and ω. The long pulse limit is very singular, and, for ω = 0, the survival probability is const λ, m...