Symmetry problems in harmonic analysis are formulated and solved. One of these is equivalent to the refined Schiffer’s conjecture which was recently proved by author. Let $$k=const>0$$ be fixed, $$S^2$$ unit sphere $${\mathbb R}^3$$ , D a connected bounded domain with $$C^2-$$ smooth boundary S, $$j_0(r)$$ spherical Bessel function. The symmetry stated following theorems. Theorem A Assume ...

The superconducting magnetic levitation railway system (MAGLEV) under development in Japan uses a pulsewidth-modulation (PWM) inverter for driving a linear synchronous motor (LSM). The inverter output voltage contains non-negligible harmonics which cause harmonic resonances in the LSM system, and therefore harmonics of the output voltage have been analyzed in order to control such harmonic reso...

In this paper, we propose a new combined harmonic-wavelet representation for audio where a harmonic analysis-synthesis scheme is used, rst, to approximate each audio frame as a sum of several sinusoids. Then, the di erence between the original signal and the reconstructed harmonic signal is analyzed using a wavelet ltering scheme. After each step (harmonic analysis & wavelet ltering), parameter...

harmonics have become an important issue in modern power systems. the widespread penetration of non-linear loads to emerging power systems has turned power quality analysis into an important operation issue under both steady state and transient conditions. this paper employs an extended harmonic domain (ehd) based framework for dynamic analysis of long term analysis over voltages during the tra...

Harmonic slicing has in recent years become a standard way of prescribing the lapse function in numerical simulations of general relativity. However, as was first noticed by Alcubierre [Phys. Rev. D 55, 5981 (1997)], numerical solutions generated using this slicing condition can show pathological behaviour. In this paper, analytic and numerical methods are used to examine harmonic slicings of K...

This work concerns superharmonic perturbations of a Gaussian measure given by a special class of positive weights in the complex plane of the form w(z) = exp(−|z| + U(z)), where U(z) is the logarithmic potential of a compactly supported positive measure μ. The equilibrium measure of the corresponding weighted energy problem is shown to be supported on subharmonic generalized quadrature domains ...