1 ECS University of Westminster, London, HA1 3TP, UK e-mail: [email protected] 2 Warrane College, University of New South Wales, Kensington, 1465, Australia e-mail: [email protected] 3 Department of Mathematics, Vellalar College for Women, Erode 638 009, Tamilnadu, India e-mail: [email protected] 4 Centre of Biomedical Engineering, Bulgarian Academy of Sciences P.O.Box 12, ...

We prove that in characteristic p > 0 a module with good filtration for a group of type E6 restricts to a module with good filtration for a group of type F4. Thus we confirm a conjecture of Brundan for one more case. Our method relies on the canonical Frobenius splittings of Mathieu. Next we settle the remaining cases, in characteristic not 2, with a computer-aided variation on the old method o...

High-Efficiency Cascade Modulators for the Next Generation Software-Defined-Radio Mobile Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. Morgado, R. del Rı́o, and J. M. de la Rosa xxxx A Beam Phase and Energy Measurement Instrument Based on Direct RF Signal IQ Undersampling Technique . . . . . . . . . . . . . . . . . . . ...

A new class of dithering algorithms for black and white (B/W) images is presented. The basic idea behind the technique is to divide the image into small blocks and minimize the distortion between the original continuous-tone image and its low-pass-filtered halftone. This corresponds to a quadratic programming problem with linear constraints, which is solved via standard optimization techniques....

The Low Order Wavefront Sensor (LOWFS) assembly is located at the focus of the first relay and contains as a minimum 2 Tip/Tilt WFS, 1 TTFA WFS, 1 TWFS WFS and 1 PSF monitor. The NGAO LOWFS assembly is a critical part of the NGAO system as it initiates acquisition and all subsequent observation modes such as on and off-chip dithering, including sub-pixel dithering, and non-sidereal tracking at ...

Effective compensation of phase noise in laser communication calls for fast, real-time, adaptive wavefront control. We present an analog, continuous-time, high-speed VLSI (Very Large Scale Integration) controller implementing multi-dithering perturbative gradient descent optimization of a direct measure of optical performance. The system applies parallel sinusoidal perturbations to the wavefron...

Many image display applications and printing devices allow only limited number of colours. They have limited computational power and storage to produce high quality outputs on high bit-depth colour image. A dithering technique is called for here in order to improve the perceptual visual quality of the limited bitdepth images. A dithered image is represented by a natural colour in the low bit de...

This article presents and analyzes a technique for reducing the spurious signal content in digital sinusoid synthesis. Spurious-harmonic (spur) reduction is accomplished through dithering both amplitude and phase values prior to word-length reduction. The analytical approach developed for analog quantization is used to produce new bounds on spur performance in these dithered systems. Amplitude ...