An algorithm is developed for performing parameter estimation on a small-size digital computer. First principles of matrix algebra are used to derive a sequential estimator which computes an estimate of a general parameter array A from an array of measurements Z = HA+V where V is a matrix of zero-mean noise terms. At every stage a new row is adjoined to each of Z, H. and V and a new estimate of A is calculated recursively, with any one of three well-known filtering processes available from the same basic set of recursive equations: a least-squares filter to minimize [ Formula omitted ], a maximum-likelihood filter to maximize [ Formula omitted ] or a maximum- a-posteriori filter to maximize [ Formula omitted ]. Provision is made for starting the filter either with a-priori means and variances of the parameters or with a deterministic "minimum-norm" composition based on the first s measurement rows, s being the number of rows in the parameter array. The algorithm is applied to the problem of identifying the parameters of a discrete model for a linear time-invariant control system directly from sequential observations of the inputs and outputs. Results from computer tests are used to demonstrate properties of the algorithm and the important computer programs are included, along with suggestions for further applications. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

Hardware for an electrical machines laboratory computer data acquisition system is considered. A survey of existing equipment and a study of the role of a computer system in laboratory instruction is made for the UBC electrical machines laboratory. From this, specifications for the hardware required for a data acquisition and processing system are studied and a system configuration proposed. Transducers for measuring voltage and current waveforms on a machine are considered and designed. The performance of the transducers constructed is evaluated in two sets of measurements. In the first set, measurement error, offset drift, common-mode rejection ratio, and frequency cutoff are measured for the transducer set (by itself). Measurement errors are found to be less than 1% F.S. In the second set of measurements, a system similar to the one proposed for the machines laboratory is tested. Results from this set of measurements indicate that the system design proposed is workable. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This is an instrumentation thesis. The interface system discussed is a link between an ordinary TV camera and a computer for storage of visual data. The same system can also be used as a link between the computer and a display monitor. Because of its wide bandwidth, a video signal cannot be sampled at the Nyquist rate and presented to a computer. Previous interface systems overcame the problem by scanning slowly on an element-by-element basis using a special scanner and then presenting the samples to the computer. After processing, the data would be read out at the same slow rate and displayed on a special display monitor. The interface described in this thesis will accept material obtained from an ordinary TV camera scanning at standard rate. By using a "stroboscope" sampling technique the samples are presented to the computer slowly enough for it to process. After processing, the data is displayed in a similar manner on a normally scanned monitor for evaluation. Basically the interface operates as follows: A TV camera video signal is sampled at a rate slow enough for computer acceptance. The camera scans the same picture several hundred times until all the points representing the picture have been sampled and stored, the sampling is controlled such that all the points are each sampled only once. Because of the sampling method consecutive samples in the computer do not correspond to adjacent points on the picture being stored. It may therefore be necessary to programme the computer to arrange the samples such that adjacent data in the computer represent consecutive picture points before processing. After processing, the samples may be rearranged and read out for display in the same order they were stored. The horizontal resolution of the picture being stored can be varied quite easily in steps. For example, a system designed to have a maximum of 480 points/line will also have the ability to provide such lower resolutions as 60, 120 and 240 points/lines. This variation is made possible by the design of the hardware. By software the vertical resolution can be varied between an upper limit of 525 lines per picture and such near submultiples of this as 263 and 131 lines/picture. The thesis is discussed in relation to the PDP-9 computer on which most of the work described was done. However, the system interfaces readily with other computers. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

The purpose of this study was to develop a model of investigating anxiety in human-computer interactions. The model was constructed from three components. Firstly, precursor conditions of anxiety were identified by assimilating several of the accepted theoretical viewpoints of the anxiety concept. Secondly, the computer-human interaction process was examined and typical events in this process were identified. Finally, a connection between the computer-human interaction process and anxiety was proposed by identifying a subset of specific interaction events that were representative of the anxiety inducing conditions. These were termed Computer-Interaction Anxiety (CIA) events. To test the validity of the model an experiment was carried out in which state anxiety data was collected while 31 subjects were engaged in an interactive computer programming session. There was a significant increase in the subjects' state-anxiety level immediately after experiencing typical CIA events. / Education, Faculty of / Curriculum and Pedagogy (EDCP), Department of / Graduate

The communication complexity of fundamental problems in distributed computing on an asynchronous ring are examined from both the algorithmic and lower bound perspective. A detailed study is made of the effect on complexity of a number of assumptions about the algorithms. Randomization is shown to influence both the computability and complexity of several problems. Communication complexity is also shown to exhibit varying degrees of sensitivity to additional parameters including admissibility of error, kind of error, knowledge of ring size, termination requirements, and the existence of identifiers. A unified collection of formal models of distributed computation on asynchronous rings is developed which captures the essential characteristics of a spectrum of distributed algorithms those that are error free (deterministic, Las Vegas, and nondeterministic), and those that err with small probability (Monte Carlo and nondeterministic/probabilistic). The nondeterministic and nondeterministic/probabilistic models are introduced as natural generalizations of the Las Vegas and Monte Carlo models respectively, and prove useful in deriving lower bounds. The unification helps to clarify the essential differences between the progressively more general notions of a distributed algorithm. In addition, the models reveal the sensitivity of various problems to the parameters listed above. Complexity bounds derived using these models typically vary depending on the type of algorithm being investigated. The lower bounds are complemented by algorithms with matching complexity while frequently the lower bounds hold on even more powerful models than those required by the algorithms. Among the algorithms and lower bounds presented are two specific results which stand out because of their relative significance. 1. If g is any nonconstant cyclic function of n variables, then any nondeterministic algorithm for computing g on an anonymous ring of size n has complexity [Formula Omitted] bits of communication; and, there is a is nonconstant cyclic boolean function [Formula Omitted], such that [Formula Omitted] can be computed by a Las Vegas algorithm in [Formula Omitted] expected bits of communication on a ring of size n. 2. The expected complexity of computing AND (and a number of other natural functions) on a ring of fixed size n in the Monte Carlo model is [Formula Omitted] messages and bits where [Formula Omitted] is the allowable probability of error. / Science, Faculty of / Computer Science, Department of / Graduate

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