Accurate computation of harmonics is really a challenging problem in power system. Many algorithms have been proposed for harmonic estimation. In this paper a novel hybrid approach is proposed to estimate the amplitudes and phases of fundamental, third and fifth harmonics of three different types of distorted power signals in presence of white noise. A robust estimator known as H∞ Filter is use...

Power electronic converters are non-linear time-dependent systems whose exact analysis without the use of computers is very difficult, and even using computer softwares requires a long time. Use of the state space averaging method, as will be mentioned, in addition to simplifying the analysis procedure which is a result of converting a time-dependent system to a time-independent one, reduces th...

For most conventional analyses, the power system is essentially modeled as a linear system with passive elements excited by constantmagnitude and constantfrequency sinusoidal voltage sources. However, with the widespread proliferation of power electronics loads nowadays, significant amounts of harmonic currents are being injected into power systems. Harmonic currents not only disturb loads that...

Power Quality (PQ) parameters such as voltage RMS value, Total Harmonic Distortion (THD), and Power Factor (PF) are main topics to be considered in the connection of sensitive loads to the grid. In this paper, a Unified Power Quality Conditioner (UPQC) based on an Indirect Matrix Converter (IMC) is proposed to address some PQ issues as mitigation of voltage harmonics and compensation of sags an...

We calculate the dynamics and the radiation emitted from free electrons in an ultrashort pulsed laser focus. In a Gaussian focus, at low electron densities for which space charge is negligible, we find that ponderomotive forces limit the effective volume of radiation emission to a region that is much smaller than the focal waist and even significantly smaller than the fundamental wavelength. Co...

Visual appearance can be phenomenologically modeled through an integral equation, known as reflectance equation. It describes the surface radiance which depends on the interaction between incident light field and surface Bidirectional Reflectance Distribution Function (BRDF). Being defined on the Cartesian product of the incident and outgoing hemispheres, hemispherical basis is the natural way ...

We present a spectral method for solving elliptic equations which arise in general relativity, namely three-dimensional scalar Poisson equations, as well as generalized vectorial Poisson equations of the type ∆ ~ N + λ~ ∇(~ ∇ · ~ N) = ~ S with λ 6= −1. The source can extend in all the Euclidean space R, provided it decays at least as r−3 (scalar case) or r−4 (vectorial case). A multi-domain app...

As objects vibrate, they cause changes in the air pressure, which our ears perceive as sounds that could be translated by our brains as speech, music or noise (Garba 2007b). The four basic characteristics of sound include frequency, amplitude, harmonics and direction from which a sound is coming. The frequency describes the rate at which the air vibrates per second, measured in hertz (Hz). Ampl...

Bright, circularly polarized, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly polarized driving laser fields. Although the resulting circularly polarized harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly pola...

This paper introduces orthogonal non{bandlimited wavelets on the sphere with respect to a certain Sobolev space topology. The construction of those kernels is based on a clustering of the index set N = f(n; k) 2 N0 Zj n k ng associated to the system of spherical harmonics fYn;kg(n;k)2N . The wavelets presented here form reproducing kernels of the spans of the clustered harmonics. More explicitl...