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This paper describes a hybrid computer microprogram which plots frequency domain responses for linear systems. The microprogram computes the real and imaginary parts of the system output and displays either Bode or Nyquist plots. Various approaches are discussed and a detailed explanation of the one selected is presented. The major areas of discussion are the sinewave generator, the computation of real and imaginary parts of the system output, the logarithm computation and the digital control logic. The conclusion give s comparison of a Nyquist plot made with the microprogram with one calculated by a digital computer. Possible improvements for the microprogram are also discussed.

<p> This thesis focuses on the noise model verification at both device and circuit levels using circuit simulators. The techniques and procedures developed in this thesis are general and can be applied to any proposed RF noise model equations. To fulfil the two tasks, three main topics have been accomplished. First, a general noise source implementation method has been presented in detail in this thesis and is verified with measurements for both long and short-channel MOSFETs. This method provides a simple and effective way to implement the enhanced channel noise and induced gate noise of MOSFETs without increasing the simulation complexity for the simulators.</p> <p> Second, a systematic procedure to refine the model parameters used in noise calculation is presented. For a model to accurately predict the HF noise characteristics, the accuracy in the prediction of both DC and AC characteristics has to be ensured. The procedure proposed in this thesis provides both DC and AC model parameter verification and optimization for RF noise simulation purpose.</p> <p> Third, as for benchmark circuits to verify noise model at the circuit level, two LNA designs are proposed in the thesis. The first design gives the emphasis on the noise reduction technique and the LNA design procedure. The proposed noise reduction technique gives circuit designers more control on noise figure minimization through noise matching. The second design is used to experimentally verify the noise model at the circuit level.</p> / Thesis / Master of Applied Science (MASc)

<p> Centre of pressure (CP) excursion frequency characteristics of normal and visually impaired children were examined. Thirty-six normal (N) children and 12 visually impaired (VI) children stood on a force platform under 4 conditions (eyes open or closed, normal or foam surface). CP excursions were analyzed by fast Fourier transformation. Total power was calculated between 0-4 Hz, and percent of total power was calculated in the low (0-1 Hz) and high (1-4 Hz) bands. Linear regression was performed on logarithmically transformed data and the slope was used to compare the relative power at low and high frequencies. Analysis of covariance removed the variance due to height in the N children. The Mann-Whitney test compared theN and VI children. Total power decreased with age. Young children (4-7 years) had more high frequency power. Young children may respond intermittently to feedback with ballistic type movements while older children may continuously monitor and respond to sensory feedback. Vision helped control CP adjustments, but power did not increase between 0-1 Hz with eyes closed. VI had higher total power on the normal surface. With eyes closed the differences were more obvious in the older children (10-12 years) which suggests vision is important in development to fine-tune the sensory systems. The foam reduced pressor receptor feedback, reducing the advantage of more finely tuned somatosense in N children. VI children had more low frequency power than N children (A-P). Young VI children did not have a large amount of high frequency power, as the N children did, suggesting that VI children may adapt at a younger age to continuously monitor and respond to feedback without relying on intermittent ballistic type responses. </p> / Thesis / Master of Science (MSc)

<p> Animal studies have shown that the tonotopic organization of the auditory cortex is not statically fixed, but can be remodeled by experience. The purpose of this study was to investigate whether or not frequency discrimination training can induce changes in the cortical representation of a selected frequency in humans. Six human subjects were trained for approximately 3 weeks to detect a change in pitch between two tones (40Hz amplitude modulated) using a standard frequency of 2040 Hz. Each subject was tested on his/her discriminative ability before and after training using three different standards (2040Hz, 1840Hz, and 2240Hz). EEG data were recorded both before and after training and changes in transient and steady-state responses were investigated. Behaviourally, every subject improved at the discrimination task using the trained frequency. However, only three subjects demonstrated transfer to both untrained frequencies. In the EEG data, the P2-Nl amplitude increased in five of the six subjects and the Nllatency decreased in all six for the 2040Hz set. These two findings were statistically significant (p<0.05) for the group. There were no statistically significant findings for the side frequencies. The change in the 40 Hz steady-state response was also not significant, increasing in three subjects and decreasing in the other three. These findings indicate that changes are expressed in the secondary auditory cortex. These findings may also be applicable to the treatment of tinnitus. </p> / Thesis / Master of Science (MSc)