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A CMOS analogue circuit for Gaussian noise generation as well as a novel circuit for transforming Gaussian noise into uniform noise, both designed for operating with a supply voltage of 1.5V, are presented. Both circuits are optimized for a 0.35 {\ensuremathμ}m standard CMOS technology using an equation-based design methodology based on genetic algorithms. Electrical simulations demonstrate that high noise amplitudes together with reasonable bandwidths can be achieved with relatively low power dissipation. Potential applications include self-calibration and on-chip self-testing of video-rate analogue-to-digital converters.

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Rail corrugation is a phenomenon that leads to a waving in the rails with wavelengths typically between 3 cm and 100 cm and amplitude levels of several microns. The genesis of this waving is complex. Rail corrugation is a recognized problem that leads to excess vibration on the rails and vehicles to a point of reducing their life span and compromising safety. In urban areas excess vibration noise is also a problem. A software tool was developed to analyze accelerometer signals acquired in the boggies of rail vehicles in order to quantify the rail corrugation according to their frequency and amplitude. A wavelet packet methodology was used in this work and compared with the One Third Octave Filter (OTOF) power representations, which is currently used in the industry. It is shown that the former produces better results.

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