Electrical and Computer Engineering Commons^™

Fourier Based Three Phase Power Metering System, Scott C. Smith, M. J. Devaney

Electrical and Computer Engineering Faculty Research & Creative Works

The increased application of higher frequency nonlinear loads, such as electronic fluorescent ballasts and higher speed adjustable drives, has resulted in the need to monitor the higher power system harmonics which were largely ignored in earlier power monitors. Addressing this need requires a meter with substantially higher sample rate and greater computational power. This paper describes a zero-blind, three-phase, three-element power meter that samples three voltages and four currents at 256 points per cycle. The instrument relies on the FFT to compute real and reactive power at each harmonic and reports total real, reactive, and distortion power on each phase. …

Comparison Of A Heuristic Dynamic Programming And A Dual Heuristic Programming Based Adaptive Critics Neurocontroller For A Turbogenerator, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a neurocontroller for a turbogenerator that augments/replaces the conventional automatic voltage regulator and the turbine governor. The neurocontroller uses a novel technique based on the adaptive critic designs with emphasis on heuristic dynamic programming (HDP) and dual heuristic programming (DHP). Results are presented to show that the DHP based neurocontroller is robust and performs better than the HDP based neurocontroller, as well as the conventional controller, especially when the system conditions and configuration changes.

Comparison Of Text-Dependent Speaker Identification Methods For Short Distance Telephone Lines Using Artificial Neural Networks, Ganesh K. Venayagamoorthy, N. Sundepersadh

Electrical and Computer Engineering Faculty Research & Creative Works

The transition to democracy in South Africa has brought with it certain challenges. The main challenge is to get rid of crime and corruption. The paper presents a technique to combat white-collar crime in telephone transactions by identifying and verifying speakers using artificial neural networks (ANNs). Results are presented to show that speaker identification is feasible and this is illustrated with two different types of ANN architectures and with two different types of characteristic features as inputs to ANNs.

Decentralized Online Neuro-Identification Of Turbogenerators In A Multi-Machine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new and a novel technique based on Artificial Neural Networks (ANNs) for nonlinear model of turbogenerators in a multi-machine power system. Only local measurements are required by each ANN in this new method, and hence it is called decentralized neuro-identificiation. Each turbogenerator in the power system is quipped with an ANN which is able to identify (or model) its particular turbogenerator from moment to moment This information can then be used by a second ANN at each generator to enable effective control of the nonlinear non-stationary process under all operating conditions. Simulation results are presented in …

Neurocontroller Alternatives For "Fuzzy" Ball-And-Beam Systems With Nonuniform Nonlinear Friction, Danil V. Prokhorov, Donald C. Wunsch, Paul H. Eaton

Electrical and Computer Engineering Faculty Research & Creative Works

The ball-and-beam problem is a benchmark for testing control algorithms. Zadeh proposed (1994) a twist to the problem, which, he suggested, would require a fuzzy logic controller. This experiment uses a beam, partially covered with a sticky substance, increasing the difficulty of predicting the ball's motion. We complicated this problem even more by not using any information concerning the ball's velocity. Although it is common to use the first differences of the ball's consecutive positions as a measure of velocity and explicit input to the controller, we preferred to exploit recurrent neural networks, inputting only consecutive positions instead. We have …

Power Education At The Crossroads, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

To meet the demands of designing and running far more complex and highly integrated electricity systems, a new kind of power engineer is needed. In this paper, the author describes how, though students tend to favor higher-tech and more lucrative fields than power Engineering; reports of the discipline''s demise are exaggerated

High Frequency Characteristic Studies Of The N-Channel Enhancement Mode Power Mosfet Device, Rosli Sahrani

Student Works (2000-2009)

The n-channel enhancement mode power MOSFET device which is known to have the highest switching speed among the controllable switches group is the device studied in this research work. This commercially packaged device manufactured. by Harris Semiconductor has a combination ofMOSFET and JFET structures superimposed. It has a p-type MOS gate and a reversed biased field induced pin junction laterally at the surface and a vertical JFET structure. A Keithley 590 C-V Analyz.er was used to characterize this device. High frequency (1MHz) capacitance-voltage (C-V) and conductance-voltage (G-V) characteristic were measw-ed across the gate-source, gate-drain and source-drain tenninals of the device. …

Improved Resolution Backscatter Measurements With The Seawinds Pencil-Beam Scatterometer, David G. Long, Michael W. Spencer, Chialin T. Wu

Faculty Publications

The SeaWinds scatterometer was launched on the NASA QuikSCAT spacecraft in June 1999 and is planned for the Japanese ADEOS-II mission in 2000. In addition to generating a global Ku-band backscatter data set useful for a variety of climate studies, these flights will provide ocean-surface wind estimates for use in operational weather forecasting. SeaWinds employs a compact "pencil-beam" design rather than the "fan-beam" approach previously used with SASS on Seasat, NSCAT on ADEOS-I, and the AMI scatterometer on ERS-1, 2. As originally envisioned and reported, the resolution of the SeaWinds backscatter measurements were to be antenna-beamwidth limited. In order to …

New Free-Space Multistage Optical Interconnection Network And Its Matrix Theory, Fengguang Luo, Mingcui Cao, Anjun Wan, Jun Xu, Xinjun Zhou, Cong Deng

Electro-Optics and Photonics Faculty Publications

A new free-space multistage optical interconnection network which is called the Comega interconnection network is presented. It has the same topological construction for the cascade stages of the Comega interconnection. The concept of the left Comega and the right Comega interconnection networks are given to describe the whole Comega interconnection network. The matrix theory for the Comega interconnection network is presented. The route controlling of the Comega interconnection network is decided based on the matrix analysis. The node switching states in cascade stages of the 8 by 8 Comega interconnection network for the route selection are given. The data communications …

Cellular Automata Study Of The Feasibility Of A Parallel Optical Computer, Jason Robert Lane

Masters Theses

"The speed of modern electronic computers has inherent design limitations which will soon be reached. A possible substitute is the optical computer. In this project, the feasibility of the optical computer is explored by designing and building a parallel optical system. This system is used to test the basic principles that would govern a parallel optical computer. The system is based on the principle of cellular automata, which is a simulation technique used to study interactions of objects in a system. The following goals were set. The system would be based on cellular automata. A one-dimensional array with nine cells, …

Investigation Of Pattern Classification And Feature Selection Of Gaussian Processes, Vivek Ramaprasad

Masters Theses

"This thesis focuses on the application of statistical techniques for pattern classification where the patterns are power spectra of the recorded acoustic signals of occluded objects. Different approaches used to classify are : The Bayes linear and piece-wise linear classifiers, the correlation classifier, classification using error spectra and the clustering algorithm. Classifiers were designed and experiments were conducted to investigate the performance. The performance is evaluated in terms of the percentage efficiency by counting the number of vectors identified correctly and the number of vectors which were misclassified. The feature vectors from primitive measurement space is then reduced to lesser …

Vhdl Design And Simulation For Embedded Zerotree Wavelet Quantisation, Hung Huynh

Theses : Honours

This thesis discusses a highly effective still image compression algorithm – The Embedded Zerotree Wavelets coding technique, as it is called. This technique is simple but achieves a remarkable result. The image is wavelet-transformed, symbolically coded and successive quantised, therefore the compression and transmission/storage saving can be achieved by utilising the structure of zerotree. The algorithm was first proposed by Jerome M. Shapiro in 1993, however to minimise the memory usage and speeding up the EZW processor, a Depth First Search method is used to transverse across the image rather than Breadth First Search method as initially discussed in Shapiro's …

Time Delayed Process Model Parameter Estimation: A Classification Of Techniques, Aidan O'Dwyer

Conference papers

An extensive though scattered literature exists on the estimation of the model parameters of time delayed processes. However, it is possible to identify themes that are common to many of the proposed techniques. The intention of this paper is to provide a framework against which the literature may be viewed.

A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 1: Pi Controller Tuning Rules, Aidan O'Dwyer

Conference papers

The ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. A summary of tuning rules for the PI control of single input, single output (SISO) processes with time delay is provided in this paper.

A Summary Of Pi And Pid Controller Tuning Rules For Processes With Time Delay. Part 2: Pid Controller Tuning Rules, Aidan O'Dwyer

Conference papers

The ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. A summary of tuning rules for the PID control of single input, single output (SISO) processes with time delay is provided in this paper.

A Novel Fpga-Based Master/Slave Pci Interface Core, Chris Brueggen, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

Current high-density, high-speed devices such as Xilinx's Virtex FPGAs are more than capable of implementing a 64-bit, 66 MHz PCI bus interface and associated application specific logic. This paper presents a novel design for an FPGA-based PCI bus interface, which is being used in the development of a medical ultrasound instrument.

Automated Identification Of The Operational Modes Of Switched Electric Circuits, J. Jatskevich, O. Wasynczuk, E. A. Walters, C. E. Lucas, Steven Pekarek, P. T. Lamm

Electrical and Computer Engineering Faculty Research & Creative Works

In the analysis of power-electronic-based energy conversion systems, it is important to identify the operational modes of the associated converters and inverters. However, as the number of switching elements increases, it becomes more difficult to analytically establish all possible modes of operation. In this paper, a modelling technique is described wherein a state-space representation of the overall system is generated automatically and updated dynamically as each new topology is encountered. Utilizing this approach, it becomes possible to identify the operational modes of converters and inverters based upon the cyclically repeated sequences of topologies that can be observed during steady-state operation. …

An Analog Front-End Speech Processor Using The Ratio Spectrum, John G. Harris, Shao Jen Lim

Electrical and Computer Engineering Faculty Research & Creative Works

We have combined the standard front-end filter bank with a feature extraction process to produce a model that requires dramatically less hardware (or software). This new model, based on the frequency-sampled ratio spectrum, can be interpreted as a small set of constant-Q filters whose center frequencies adapt to locations of high signal energy. The resulting feature vectors are shown to outperform several competing techniques for phoneme recognition. Results from fabricated CMOS analog VLSI circuits illustrate a hardware efficient method to sample the ratio spectrum.

A Probabilistic Analysis Of The Ratio Spectrum, M. D. Skowronski, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, Lim and Harris (see IEEE International Symposium on Circuits and Systems, p.277-80, June 1998) developed a novel spectral representation called the ratio spectrum. The ratio spectrum is formed by taking the ratio of the power of a low pass filtered signal to the power of the original unfiltered signal for all filter cutoff frequencies. Features extracted from the ratio spectrum have proven to be promising for phoneme recognition and speech compression. In this work we have shown that the ratio spectrum feature sets are competitive with standard feature sets used for automatic speech recognition. To understand the underlying properties …

Monaural Cue Sound Localizer, John G. Harris, Chiang Jung Pu, Jose C. Principe

Electrical and Computer Engineering Faculty Research & Creative Works

We describe the first single microphone sound localization system and its inspiration from theories of human monaural sound localization. Reflections and diffractions caused by the external ear (pinna) allow humans to estimate sound source elevations using only one ear. Our single microphone localization model relies on a specially shaped reflecting structure that serves the role of the pinna. Specially designed analog VLSI circuitry uses echo-time processing to localize the sound. A CMOS integrated circuit has been designed, fabricated, and successfully demonstrated on actual sounds.

A Silicon Olfactory Bulb Oscillator, Vitor M.Grade Tavares, Jose C. Principe, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a low power MOS-VLSI implementation of an oscillator proposed by Freeman to model a very important component of the olfactory cortex. The model dynamics has time constants in the order of 1/220 (s). To accomplish the long-time constants a new filtering technique recently proposed was utilized. All the blocks involving information processing were designed to operate below threshold (weak inversion).

Additional Quality Factors For The World Wide Web., Ronan Fitzpatrick

Conference papers

Web site development is maturing from the enthusiastic experimental practice of early years to a more professional discipline, addressing the needs of Web site visitors and owner organisations. Quality is central to this maturing and it is necessary to have a full understanding of the meaning of quality in the context of the ever-changing Web. This paper identifies five new quality factors for the Web (visibility, credibility, intelligibility, engagibility and differentiation), together with their characteristics and a checklist of enablers, which can be used by specifiers, designers, developers and evaluators to create quality Web sites.

Stochastic Stability Of The Continuous-Time Extended Kalman Filter, K. Reif, S. Gunther, Edwin E. Yaz, R. Unbehauen

Electrical and Computer Engineering Faculty Research and Publications

he error behaviour of the extended Kalman filter is analysed. It is proved that the estimation error remains bounded if the system satisfies a detectability condition and both the initial estimation error and the disturbing noise terms are small enough. Moreover, some selected cases with both bounded and unbounded estimation error are demonstrated by numerical simulations.

Voice Command Controller, Hoang Nghia Nguyen

Theses : Honours

Signal processing technology has been strongly developed and it has attracted interest from scientists and engineers around the world from the last decade. Speech synthesis and speech recognition are particular topic in the field that have been widely used and developed in many different area such as business, controlling, education and entertainment. The project's main objective is to study and develop an application program with the Speech SDK through design and implementation of Tele-Control system based on the commercial product of National Semiconductor: Carrier-Current Transceiver (LM 1893) and Speech development kit (Speech SDK4.0) from Microsoft Corporation. The project is suitable …

A Hierarchical Channel Selection Scheme For Macro/Micro Cellular Networks, Ayesha Zaheer

Retrospective Theses and Dissertations

Hierarchical channel allocation schemes for cellular networks offer a promising approach to solve the pressing problem of increasing the cellular servicing capacity in spite of the limited radio spectrum available. We propose a hierarchical channel selection scheme for handling handoffs and new calls in micro/macro cellular systems. The scheme is intended to improve the performance and quality of service of these systems by increasing the cell channel utilization, reducing the handoff blocking probability and improving the responsive to new calls.

The proposed scheme is based on several design enhancements including an overflow buffer, which is used for handoff calls that …

Signal Integrity In Deep Submicron Cmos Chip Design, Jignesh Suresh Sonchhatra

Retrospective Theses and Dissertations

Advancement in CMOS technology has become a driving force in the advancement of today's IC design arena. In the past few years, considerable research has been done on the CMOS devices and circuits. Constant efforts have been made to realize smaller and smaller devices by reducing the channel length of the transistors and scaling down various other device parameters. Consequently, various problems have arisen such as interconnect delay, signal integrity and signal coupling.

The purpose of this thesis is to review and understand current problems in IC design and come up with various solutions to them. Efforts have been made …

A Comparative Analysis Of Two Independent Power Plants Under Different Ownership, Rangash Natarajan

Student Works (2000-2009)

Many governments have turned to private investors, especially Independent Power Producers (IPPs), to provide some or all of the nation's power requirements. The main reasons for this are: a) to eliminate the financial burden of the government, b) to promote competition in the generation sector to improve operating efficiency and reduce generating cost, and c) to transfer power generation technology, especially in the developing nations, at a rapid pace. In line with world trends, the Malaysian government, in 1993, deregulated its power generation sector. This was done in order to overcome the shortage of installed capacity due to an increase …

Optimisation Of Transverse Arc Array Laser, Albert Kok Foo Ng

Student Works (2000-2009)

A novel discharge scheme is proposed for the pumping of short wavelen,gth lasers. This scheme had been tested to produce fast current pulse and a 5 kA current in 60 nsec is obtained. Lasing action has been observed by using nitrogen gas. The laser line is 337 nm from the strong transitions of nitrogen molecules. The new discharge scheme is based on the concept of an arc array amplifier. It essentially consists of 48 pairs of electrodes which are lined up to form an array of arc discharge. Its electrical circuitry allows each pair of the electrodes to be decoupled …

Investigations Of Transverse Arc Array Laser Action In Nitrogen Gas, Kee Siang Goh

Student Works (2000-2009)

In almost all pulsed gas lasers, transverse electrical discharge is employed in the excitation of the atoms or molecules. These lasers normally employ discharge across a pair of common electrodes to provide large volume and uniform glow discharge. The scaling of output power in such lasers is obtained by increasing the volume of the discharge and also the pressure of the discharge gas. For this reason. the energy coupled into the discharge channel is kept low enough to avoid arcing. Under these circumstances, the electron temperature of such uniform glow discharge is not sufficient to produce excitation of VUV or …

Design And Integration Of A Co2 Laser Hybrid Cuting System For Materials Processing, Chee Hong Tan

Student Works (2000-2009)

A CO2 laser cutting system has been designed and developed based on hybrid motion of moving workpiece and moving beam. 1bis system has been utilised in the studies of laser cutting of various materials in various profiles. The structural design of the laser cutting system was carried out with AutoCAD Mechanical Desktop. The planning included materials selection, system configuration and re-use of existing available components in order to minimise the research budget. A fast-axial-flow CO2 laser was adopted and optimised for high output power. The beam delivery system and the laser head were designed and integrated to the entire system. …