Engineering Commons^™

An Implementation Of Mht Algorithm For Adaptive Transform Coding Of Speech, Peter Battenschlag

Theses

The Modified Hermite Transform (MHT), a suboptimum block transform scheme, is implemented on a TMS320C25 signal processing system with the objective of reducing the redundancy in speech signals and transmit a quantized vector representation at bitrates as less as 0.5 bits per sample.

The generation of the Hermite polynomials with a binomial and several first order IIR filter structures is presented focusing on the fact that no muliplications are required which simplifies the MHT algorithm considerably.

An assembler program performs forward and inverse transformation together with a vector quantization using adaptive bitallocation based on short-time statistics for the transform coefficients. …

Uniformity Corrector And Signal Processing For A 160 X 244-Element Ir-Ccd Camera With Ptsi Schottky-Barrier Detectors, Paul D. Blume

Theses

An off-set-type, one point response uniformity corrector and the associated signal processing circuits was developed to be used for a 160 x 244-element IR-CCD camera with PtSi Schottky-barrier detectors. Image sensors with PtSi Schottky-barrier detectors exhibit two types of noise in the displayed video output, a temporal noise and a spatial fixed pattern noise. The performance of the image sensor, limited by the spatial noise which obscures low contrast detail and limits camera sensitivity, can be improved by a uniformity corrector. The uniformity corrector was constructed to substantially reduce the spatial noise in the output display by digitally subtracting a …

Time Series Analysis Of Respiration Component In Heart Rate Variability, Anuradha Ramaswamy Iyengar

Theses

Time series signal processing techniques (Fourier based) were applied to analyze the relationship between heart rate and respiration. This analysis takes advantage of the different timing charecteristics of the autonomic nervous system inputs to analyze their influence on the heart rate.

Data from three experiments were analyzed. The first set of data was from helicopter pilots of the US Army. They injected atropine into themselves on certain days. The effect of atropine on the heart rate spectrum and the relationship between heart rate and respiration was studied. It was found that atropine abolishes the respiration peak in the heart rate …