<p>Based on Altman's model, a state model and a measurement model are obtained. Both models are linearized and the linear state variable feedback method is then applied to decouple the linearized system.</p> <p>Computer programmes for decoupling are written and the results are then discussed.</p> <p>Suggestions for future work are proposed.</p> / Master of Engineering (ME)

<p>By making use of measurements of the input and output of an unknown system, the characterizing parameters are found by using matrix pseudoinverse method. For noise-corrupted measurement, least squares estimation of the parameters are obtained.</p> <p>Stochastic approximation is employed to improve the estimation.</p> <p>Both methods are tested on-line in real time using the PDP-11/45 minicomputer while the system is simulated on the TR-20 analog computer.</p> / Master of Engineering (ME)

<p>This thesis covers the design and fabrication of a Surface Acoustic Wave (SAW) oscillator. The oscillator was designed to operate at 124 MHz in the fundamental mode and was constructed on an ST-X quartz substrate. The type of SAW oscillator incorporated was of the delay line type where a SAW delay line is inserted in the feedback loop of an amplifier with excess gain. The delay line exhibited a bandpass characteristic with an insertion loss of 32 dB. The oscillator has a short-term stability of 2.0 parts in 10⁷over 1 second and a medium-term stability of less than 8 ppm over 12 hours. The oscillator had an effective loaded Q of 628 and power output was -10 dBm into 50 Ω with the second harmonic down 22 dB, and the third down 33 dB. The theory of operation of the SAW delay line oscillator is covered along with fabrication procedures and experimental results.</p> / Master of Engineering (ME)

<p>The concepts of the analogue channel vocoder and digital FFT vocoder are utilized in the analysis of a Walsh vocoder. The FFT and Walsh vocoders are simulated in Fortran on a CDC6400 computer. The simulations contain a simplified cepstrum pitch detector to simulate a hardware pitch detector. The Walsh vocoder simulation is identical to the FFT vocoder simulation with the Fast Walsh Transform operation replacing the Fast Fourier Transform operations (FWT and FFT respectively) in the channel signal calculations and transforms into the time domain.</p> <p>Sentences of different lengths and speakers are processed by the simulated vocoders and the resultant synthesized speech is analyzed for comparative quality and intelligibility.</p> <p>An unsuccessful attempt is made to effect a vocoder which does not require a pitch detector with the calculation of the time invariant sequency power spectrum replacing the channel signal calculations in the vocoder simulations. Long term frequency and sequency enveloped are used to shape the frequency and sequency power spectra derived from the transmitted time invariant sequency power spectrum in the FFT and Walsh vocoder simulations respectively.</p> / Master of Engineering (ME)

<p>The purpose of this thesis is to present a model for magnetic domains wholly situated inside an ion implanted channel. In this model, ion implantation is assumed to change the saturation magnetization, the wall energy density, and the in-plane susceptibility. As a result the channel and the domain induce magnetic pole distributions on the channel walls which interact with the bubble domain, altering its geometry and energy. An analysis for a circular domain with variable penetration and location in the channel, as well as a variational formulation for a generally deformable domain of fixed penetration in the implanted channel, are presented. The latter case has been programmed and the results obtained are discussed. The case of a domain penetrating into the unimplanted region outside the channel is also considered.</p> / Master of Engineering (ME)

<p>In this work, a computer simulation for ion implantation has been carried out based on a simplified random model. This simulation has been used to obtain range profiles and deposited damaging energy distributions, for any system and for a wide energy range. The obtained distributions show good agreement with the third order Edgeworth expansion approximation of the standard transport theory solution (the WSS theory). By taking into account the motion of the first knock on atoms, as well as the incident ion itself, a good agreement between the simulation and the WSS theory is found for the damage distribution. A random model for dealing with poly-atomic targets is presented. Results obtained show good agreement with the available experimental results for range profiles. The simulation includes obtaining a complete picture of the collision cascade (in space and time). The complete picture of the collision is discussed in relation to the recently observed "molecular effect" and explains some available experimental results. The examination of typical cascades suggests that high energy density regions are responsible primarily for the obtained departures from "Linear Cascade Theory".</p> / Master of Engineering (ME)

<p>The problem of adaptive state estimation which involves the identification of the Kalman gain matrix without a priori information on the noise statistics is presented. A scheme incorporating an identification algorithm and a tracking algorithm is proposed. This scheme provides a powerful approach for adaptive state estimation.</p> <p>An ARMA model for system description is derived for preliminary analysis of the noise transition matrix when the observation noise is sequentially correlated.</p> <p>The innovations process for systems with coloured observation noise is shown to be white for optimum filtering.</p> <p>Simulations are performed on an inertial navigation system for both white and coloured observation noise. Numerical results indicate the superiority of the filter with tracking over one without. Performance of the filter for coloured observation noise confirms the theoretical derivation of the ARMA model.</p> / Master of Engineering (ME)

<p>Recently the problem of dynamic instability has been increased due to the recent trends in synchronous machine design and the growth in the relative size of the power stations. In this thesis such a problem has been examined by analysing the damping and synchronizing torque coefficients. Different methods for calculating those torque coefficients have been reviewed, and a new method based on a more accurate representation for the machine has been developed. Because of the more detailed representation the new resultant torque coefficients permit the investigation of additional properties of those coefficients, as well as more precise analysis of the properties previously studied. The problem of weak or negative damping associated with the use of high gain and quick response static exciters has been given special attention. Different schemes for producing a stabilizing signal have been discussed. A design procedure for a stabilizer which assures successful operation over the whole generation range has been outlined.</p> / Master of Engineering (ME)

<p>Theory, design and fabrication of a Surface Acoustic Wave (SAW) TV-IF filter is presented in this thesis. The filter is a linear phase bandpass filter with a passband extending from 41.25 to 47.25 MHz. Optimization techniques were used for designing the filter impulse response. Conventional photolithography was used for the device fabrication. The results obtained correspond very well to the theoretical design.</p> / Master of Arts (MA)

<p>The estimation of the direction of a plane wave incident upon a linear receiving antenna array and field-mapping techniques are considered in this thesis. The emphasis of the presentation is directed towards radar, and specific attention is given to the situation where the incident plane wave is corrupted by the effects of multipath propagation.</p> <p>First, the phenomenon of multipath and its experimental simulation are discussed. It is then pointed out how conventional linear array processing techniques fail in the presence of multipath propagation. These considerations lead us to consider other nonlinear array processing techniques.</p> <p>There are two such approaches considered. The first is the modification of statistical time series analysis to suit the array processing application. The Burg method and the least-squares (LS) algorithm developed by Ulrych and Clayton are two time-series methods which are discussed in detail. Results show that the Burg method is not applicable in this application, where it is shown that the LS algorithm behaves well at high SNR.</p> <p>The second approach considered is the maximum likelihood (ML) formulation. There are also two realizations of this approach which are discussed in depth. Both realizations are based on setting up the appropriate likelihood functions for the situation considered; then, the resulting structure is modified so that the required optimizations need only be performed in the specific parameter(s) of interest. This results in a more computationally efficient estimator.</p> <p>The first ML formulation discussed in applicable only to the specular multipath environment. In this situation, the direct and reflected signal components are symmetrically positioned in elevation about the normal of the array. This configuration results in a particularly simple estimator structure. The second ML formulation considered is the case where the individual signal components may be incident from arbitrary directions. The results indicate that both these ML methods perform better than the time-series techniques.</p> <p>The performance for each method is compared to the corresponding theoretical values. The results are checked by computer simulation and are validated by the use of an experimental multipath simulation system built during the course of this work.</p> / Doctor of Philosophy (PhD)