This paper presents a method for combining a particle swarm optimization with nonlinear time-varying evolution and orthogonal arrays (PSO-NTVEOA) in the planning of harmonic filters for the high speed railway traction system of Distributed Generation (DG) system with specially connected transformers in unbalanced three-phase power systems. The objective is to minimize the cost of the filter, th...

This paper proposes an improved control method based on modified Delta-Sigma Modulator (DSM) to enhance transient response and improve harmonic contents of buck DC-DC converter. The main advantages of the proposed method are improving the output voltage frequency spectrum, correction of the output voltage harmonic contents and sideband harmonics, reduction of switching noise peaks at the output...

Frequency-scanned excitation profiles of coherent second harmonic generation (SHG) were measured for silver nanoparticle arrays prepared by nanosphere lithography. The frequency of the fundamental beam did not coincide with the localized surface plasmon resonance (LSPR) of the nanoparticles and was tuned so that the coherent second harmonic (SH) emission was in the region of the LSPR at 720-750...

A new and efficient room acoustics simulation software package for MATLAB is presented which can simulate recordings of arbitrary microphone arrays within an echoic room. This simulator supports research related to developing and experimenting with multichannel microphone arrays and higher order ambisonic playback. Based upon the work by Schimmel et al. [1], this new simulation software package...

We show that waveform-synthesized chirped laser fields are efficient tools for coherent harmonic control. A single harmonic order, or two harmonic orders, can be selectively enhanced by using a two-color field allowing a moderate linear chirp for each color. Different harmonic orders within a wide spectral range can be selectively enhanced by adjusting the laser parameters. Our theory bridges t...

Starting from wavelet analysis of chaotic signals’ time-frequency characteristic, we propose a new harmonic signals extraction method using Empirical Mode Decomposition (EMD). We analyze features of chaotic signals using wavelet transform to determine the parameters of harmonic signals and interference signals. The harmonic signals as source signals are hidden within chaotic energy accumulation...

We present experimental demonstration and analysis of enhanced surface second harmonic generation (SHG) from hexagonal arrays of silicon pillars. Three sets of Si pillar samples with truncated cone-shaped pillar arrays having periods of 500, 1000, and 2000 nm, and corresponding average diameters of 200, 585 and 1550 nm, respectively, are fabricated by colloidal lithography and plasma dry etchin...

Spherical microphone arrays provide a new and promising tool for the spatial analysis of complex sound fields. Considerable previous work has investigated the use of spherical microphone arrays for phase-mode beamforming, which relies on the Bessel-weighted spherical harmonic transform of the sound field. In this paper, we investigate the advantages that spherical microphone arrays provide for ...