560 research outputs found
Phase cascade bridge rectifier array in a 2-D lattice
We report on a novel rectification phenomenon in a 2-D lattice network consisting of NĂ—N sites with diode and AC source elements with controllable phases. A phase cascade configuration is described in which the current ripple in a load resistor goes to zero in the large N limit, enhancing the rectification efficiency without requiring any external capacitor or inductor based filters. The integrated modular configuration is qualitatively different from conventional rectenna arrays in which the source, rectifier and filter systems are physically disjoint. Exact analytical results derived using idealized diodes are compared to a realistic simulation of commercially available diodes. Our results on nonlinear networks of source-rectifier arrays are potentially of interest to a fast evolving field of distributed power networks
Phase cascade lattice rectifier array: an exactly solvable nonlinear network circuit
An exact analysis of a 2-D lattice network consisting of N Ă— N sites with rectifier and AC source elements with controllable phases reveals a method for generating ripple-free DC power without the use of any filtering circuit elements. A phase cascade configuration is described in which the current ripple in a load resistor goes to zero in the large N limit, enhancing the rectification efficiency without requiring any additional capacitor or inductor based filters. The integrated modular configuration is qualitatively different from conventional rectenna arrays in which the source, rectifier and filter systems are physically disjoint. Nonlinear networks in the large N limit of source-rectifier arrays are potentially of interest to a fast evolving field of distributed power networks.MNacknowledges support from a Graduate Fellowship in the ECE department at Boston University. We thank CMaedler, R Averitt, and members of the Photonics Center staff for assistance. JC acknowledges support from the Boston University RISE summer program. (Graduate Fellowship in the ECE department at Boston University; Boston University RISE summer program)Published versio
Turbulence Time Series Data Hole Filling using Karhunen-Loeve and ARIMA methods
Measurements of optical turbulence time series data using unattended
instruments over long time intervals inevitably lead to data drop-outs or
degraded signals. We present a comparison of methods using both Principal
Component Analysis, which is also known as the Karhunen--Loeve decomposition,
and ARIMA that seek to correct for these event-induced and mechanically-induced
signal drop-outs and degradations. We report on the quality of the correction
by examining the Intrinsic Mode Functions generated by Empirical Mode
Decomposition. The data studied are optical turbulence parameter time series
from a commercial long path length optical anemometer/scintillometer, measured
over several hundred metres in outdoor environments.Comment: 8 pages, 9 figures, submitted to ICOLAD 2007, City University,
London, U
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