Richard Andrew Wiltshire

A New Class of Multilinear Functions for Polynomial Phase Signal Analysis

This paper introduces a new class of multilinear functions which can be used for analyzing a signal with time-varying frequency. The new class subsumes a number of existing functions, including the higher order ambiguity functions (HAFs), the polynomial Wigner-Ville distributions (PWVDs), and the higher order phase (HP) functions. As well as establishing a link between these existing functions, the new class provides a formalism which allows for the creation of useful new multilinear functions. A number of new functions are derived from the class.

Monitoring Individual Modal Damping Changes in Multi-modal Power System

Abstract This paper introduces a new method for rapidly detecting individual modal deterioration within the post-disturbance oscillations in large multi-modal power systems. Any “sudden change” of individual modes is detected via the cross-correlation of the whitened power spectral density of the observed signal with a reference derived from the mode of interest. A statistical characterisation of a mode’s test statistic is used to establish thresholds for detection of individual mode changes.

A Virtual Test Assessment Tool for Second Year Signal Processing Students

The development and use of a virtual assessment tool for a signal processing unit is described. It allows students to take a test from anywhere using a Web browser to connect to the university server that hosts the test. While student responses are of the multiple choice type, they have to work out problems to arrive at the answer to be entered. CGI programming is used to verify student identification information and record their scores as well as provide immediate feedback after the test is complete. The tool has been used at QUT for the past 3 years and student feedback is discussed. The virtual assessment tool is an efficient alternative to marking written assignment reports that can often take more hours than actual lecture hall contact from a lecturer or tutor. It is especially attractive for very large classes that are now the norm at many universities in the first two years.