Digital Commons Network^™

Signal Injection With Perceptual Criteria, T. Engi̇n Tuncer

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel method for increasing the coding performance and information transmission capacity is presented. This method is mainly based on perceptual modelling of input signal such as speech or audio. Presented approach may be seen as an alternative to transforms which dynamically change analysis window for better energy compaction. A perceptual model is established in order to obtain a global masking threshold in frequency below which sounds become inaudible. Certain criteria are developed for identifying the signal injection bands. A new multiband filter design method which is a generalization of windowing method is used to separate the …

State Of Art In Realistic Head Modeling For Electro-Magnetic Source Imaging Of The Human Brain, Nevzat G. Gençer, İ. Oğuz Tanzer, M. Kemal Özdemi̇r, Can E. Acar, Mert Sungur

Turkish Journal of Electrical Engineering and Computer Sciences

Electric currents produced by the neural activity in the brain create electric potentials on the scalp and magnetic field distribution outside the scalp. Measuring electric and magnetic fields provides a means to understand the spatio-temporal distribution of the neural activity. The representations of the intracellular electric current of active cell populations based on bimodal data are called electro-magnetic source image (EMSI). With the recent development of large arrays of magnetic sensors, and systems for measuring scalp voltages at more than 100 locations, it is now feasible to implement computational methods that employ numerical models which incorporate the correct geometry and …

The Gain Scheduled Piece-Wise Adaptive Digital Control Of A Ph Process, Eugene O'Shaughnessy, Aidan O'Dwyer

Conference papers

The compensation of a pH process is complicated by the non-linear nature of the process titration curve and the significant time delays that typically exist in such processes. This paper will propose the use of a gain scheduled piecewise adaptive PI controller to compensate the process. A pilot plant is controlled, with the control algorithm implemented on a programmable controller. SCADA software displays and trends the plant and controller signals.

A New Radiosonde System For Profiling The Lower Troposphere, Brian R Corner, Robert D. Palmer

Department of Electrical and Computer Engineering: Faculty Publications

A new, inexpensive radiosonde transmitter and receiver system has been developed for measuring wind field inhomogeneities in the planetary boundary layer using multiple simultaneously launched balloons. The radio- sondes use a narrowband-frequency-modulated carrier signal to transmit atmospheric pressure and temperature information to a surface receiver. The pressure and temperature data transmitted by the radiosondes allow their height above the surface to be ascertained. In addition, the radiosondes can be tracked with a photographic camera system to provide the azimuth and elevation angles of the radiosondes during their ascent, so that their three-dimensional horizontal position can be determined. By tracking the …

Comparative Study Of Stock Trend Prediction Using Time Delay, Recurrent And Probabilistic Neural Networks, Donald C. Wunsch, Emad W. Saad, Danil V. Prokhorov

Electrical and Computer Engineering Faculty Research & Creative Works

Three networks are compared for low false alarm stock trend predictions. Short-term trends, particularly attractive for neural network analysis, can be used profitably in scenarios such as option trading, but only with significant risk. Therefore, we focus on limiting false alarms, which improves the risk/reward ratio by preventing losses. To predict stock trends, we exploit time delay, recurrent, and probabilistic neural networks (TDNN, RNN, and PNN, respectively), utilizing conjugate gradient and multistream extended Kalman filter training for TDNN and RNN. We also discuss different predictability analysis techniques and perform an analysis of predictability based on a history of daily closing …

Simulation Of Madmel Power Systems Components, Timothy L. Skvarenina, Oleg Wasynczuk, Paul C. Krause, Steven Pekarek

Electrical and Computer Engineering Faculty Research & Creative Works

Detailed computer models of system components for More Electric Aircraft have been developed using the Advanced Control System Language (ACSL) and its graphical front-end, Graphic Modeller. Among the devices modeled are a wound-rotor synchronous generator with parallel bridge-rectifier outputs, a switched-reluctance generator, and various loads including a DC-DC converter, an inverter-driven induction motor, and an electro-hydrostatic actuator. Results from the simulations are presented together with corroborating experimental test results. Copyright © 1998 Society of Automotive Engineers, Inc.

A Practical Continually Online Trained Artificial Neural Network Controller For A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper reports on the simulation and practical studies carried out on a single turbogenerator connected to an infinite bus through a short transmission line, with a continually online trained (COT) artificial neural network (ANN) controller to identify the turbogenerator, and another COT ANN to control the turbogenerator. This identifier/controller augments/replaces the automatic voltage regulator and the turbine governor. Results are presented to show that this COT ANN identifier/controller has the potential to allow turbogenerators to operate more closely to their steady-state stability limits and nevertheless “ride through” severe transient disturbances such as three phase faults. This allows greater usage …

Substroke Matching By Segmenting And Merging For Online Korean Cursive Character Recognition, Chang-Soo Kim, Kang Ryoung Park, Byung Hwan Jun, Jaihie Kim

Electrical and Computer Engineering Faculty Research & Creative Works

The Korean character is composed of several alphabets in two-dimensional formation and the total number of Korean characters exceeds eleven thousand. Therefore, the previous approaches to Korean cursive characters pay most of their attention to segmenting a character into alphabets accurately. However, it is difficult because the boundaries of alphabets are not apparent in most cases. We propose an alphabet-based method without assuming accurate alphabet segmentation. In the proposed method, a cursive character is segmented into substrokes by a set of segmenting conditions. Then it is matched with the reference substrokes generated from alphabet models and ligatures by segmenting and …

Dsp Implementation Of A Quadrature Phase Shift Keying Transmitter, Andrew Phoon

Theses : Honours

The aim of this project is to develop a DSP implementation of a QPSK transmitter. This transmitter is to process digital signals in real-time and modulate it with sinusoidal and cosinusoidal signals to produce the required QPSK waveform. This thesis is mainly divided into three sections. The first section deals with the theory of modulation. Phase shift keying, in particular binary phase shift keying, is explained in some detail, with references to the generation of quadrature phase shift keying. In the second section, a brief overview of the SIMULINK package from MATLAB is given, as simulations of ideal and nonideal …

Data Logging Multiple Aviation Sensors Using A Motorala [Sic] Hc11 Microcontroller, Andrew James Wooding

Theses : Honours

This project is part of the research and development of a microprocessor based integrated instrumentation system for light aircraft. It involves interfacing a Motorola HC 11 microcontroller with several sensor inputs. The project system is designed to data log battery voltage, cylinder head temperature, ambient temperature and engine RPM.

Rtl Power Estimation Of Sequential Circuits, Sridhar Muthrasanallur

Dissertations and Theses

Power consumption has become a major concern in the electronic industry in recent years because of the increased demand for portable electronic devices. Part of the problem in power conscious design is accurate power estimation. Power estimation at low-levels of design abstraction is slow since the units of low-levels of design abstraction are transistors or gates. But designers need reliable power estimates early in the design process. Therefore designers need to have tools for fast and accurate power estimation at higher levels of design abstraction such as the Register Transfer Level (RTL).

This thesis introduces a new method for RTL …

An Approach To Exact Modeling Of The Pwm Switch, Anas N. Al-Rabadi

Dissertations and Theses

Large number of small-signal models of de-to-de power converters exists already. These models usually use two techniques. The first is the averaging technique, such as: volt-second and current-second balance, state space averaging, and the averaged modeling approach. The other technique focuses on the exact modeling approach, such as: the application of time varying systems theory to linearize networks. One of the methodologies to apply the above techniques, is to view the three-terminal systems as a two-port network.

The aim of the work presented in this thesis is to develop a new approach, by the application of the two-port network methodology …

The Design Of Cube Calculus Machine Using Sram-Based Fpga Reconfigurable Hardware Dec’S Perle-1 Board, Qihong Chen

Dissertations and Theses

Presented in this thesis are new approaches to column compatibility checking and column-based input/output encoding for Curtis decompositions of switching functions. These approaches can be used in Curtis-type functional decomposition programs for applications in several scientific disciplines. Examples of applications are: minimization of combinational and sequential logic) mapping of logic functions to programmable logic devices such as CPLDs, MPGAs, and FPGAs, data encryption, data compression, pattern recognition) and image refinement. Presently, Curtis-type functional decomposition programs are used primarily for experimental purposes due to performance, quality, and compatibility issues. However) in the past few years a renewal of interest in the …

Modeling Electromagnetic Disturbances In Closed-Loop Computer Controlled Flight Systems, W. Steven Gray, Oscar R. Gonzalez

Electrical & Computer Engineering Faculty Publications

High intensity electromagnetic radiation has been demonstrated to be a source of computer upsets in commercially available digital flight control systems. In this paper we introduce an electromagnetic disturbance model which can be used for stability analysis and augmentation of any such digitally implemented control law. The model is composed of a Markovian exosystem supplying radiation events to a discrete-time jump linear system which models how the radiation interferes with the nominal operation of the closed-loop system. We discuss how this model can be used to characterize stability and how it can be parametrized and validated in an experimental setting.

Signal Processing Topics In Multicarrier Modulation : Frequency Offset Correction For Ofdm And Multiuser Interference Cancellation For Mc-Cdma, Pingping Zong

Theses

Orthogonal frequency division multiplexing (OFDM) is discussed as a special form of multi-carrier modulation (MCM). One major problem of the OFDM system is the sensitivity to an unknown frequency offset at the receiver. To improve the performance of the OFDM system, correction of the frequency offset is required before decision making. An adaptive method of frequency offset correction is presented. The adaptation algorithm used here is based on the LMS and the estimation is proven unbiased. A multiuser communications system having similar signal structure to the OFDM system, termed as multi-carrier code division multiple access (MC-CDMA), is discussed. The MC-CDMA …

Joint Map Registration And High Resolution Image Estimation Using A Sequence Of Undersampled Images, Russell C. Hardie, Kenneth J. Barnard, Ernest E. Armstrong

Electrical and Computer Engineering Faculty Publications

n many imaging systems, the detector array is not sufficiently dense to adequately sample the scene with the desired field of view. This is particularly true for many infrared focal plane arrays. Thus, the resulting images may be severely aliased. This paper examines a technique for estimating a high-resolution image, with reduced aliasing, from a sequence of undersampled frames. Several approaches to this problem have been investigated previously. However, in this paper a maximum a posteriori (MAP) framework for jointly estimating image registration parameters and the high-resolution image is presented. Several previous approaches have relied on knowing the registration parameters …

Microelectromechanical Scanner Using A Vertical Cavity Surface Emitting Laser, Joseph G. Bouchard Jr.

Theses and Dissertations

Optical scanners play a prominent role in the commercial and military industries. The scanner's size, cost and reliability are critical characteristics. In this research a microoptical scanning system was fabricated by incorporating a vertical cavity surface emitting laser (VCSEL) onto a surface machined microelectromechanical die. The micro optics for laser beam steering includes a 135 deg mirror, a Fresnel lens, a lateral scanning rotating mirror, and a vertical scanning fan mirror. The VCSEL was attached to the die by solder and electrical connection was provided by wire bonding. Based on far field measurements the scanner had a lateral scan angle …

Atmospheric Turbulence Scintillation Effects On Wavefront Tilt Estimation, James A. Louthain

Theses and Dissertations

A new atmospheric turbulence screen generator is developed for use in performance calculations of adaptive optics systems valid over a wide range of atmospheric turbulence parameters. The screen generator accounts for diffraction effects caused by weak turbulence and incorporates the phase, amplitude, and cross statistics of the perturbed optical field. The wavefront's phase and amplitude perturbations are taken from the correlation functions developed by Lee and Harp and the cross correlation of the phase and amplitude derived in this thesis. The screen generator uses a modal representation to perform a Fourier series expansion of the wavefront phase and amplitude over …

Cepstral Processing For Gps Multipath Detection And Mitigation, Charles D. Ormsby

Theses and Dissertations

This work presents a novel approach to code phase multipath mitigation for Global Positioning System (GPS) receivers. It uses the power and complex cepstra for multipath detection and mitigation prior to code phase tracking by a standard non-coherent delay lock loop. Cepstral theory is presented to demonstrate how multipath reflection delays can be detected through the use of the power cepstrum. Filtering can then be performed on the complex cepstrum to remove multipath effects in the cepstral domain. Finally, an inverse complex cepstrum is calculated yielding a theoretically multipath free direct path estimate in the time domain. Simulations are presented …

Speaker Verification In The Presence Of Channel Mismatch Using Gaussian Mixture Models, Robert B. Reid

Theses and Dissertations

A channel compensation method is sought for use in speaker identification (ID) and verification applications under matched and mismatched training and testing conditions. This work expands on previous work on matched conditions by investigating three techniques on matched and mismatched conditions using the TIMIT and NTIMIT speech databases. First, previous results on 168 speakers are reproduced for matched conditions using Gaussian mixture models (GMM) and mel-frequency cepstral coefficients. Next, cepstral mean subtraction with band limiting (CMSBL) is investigated. The third method, developed in this thesis uses a modified Wiener filtering approach to channel compensation. New GMMs are created for each …

Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush

Theses and Dissertations

Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …

Simulation Study Of Learning Automata Games In Automated Highway Systems, Cem Unsal, Pushkin Kachroo, John S. Bay

Electrical & Computer Engineering Faculty Research

One of the most important issues in Automated Highway System (AHS) deployment is intelligent vehicle control. While the technology to safely maneuver vehicles exists, the problem of making intelligent decisions to improve a single vehicle’s travel time and safety while optimizing the overall traffic flow is still a stumbling block. We propose an artificial intelligence technique called stochastic learning automata to design an intelligent vehicle path controller. Using the information obtained by on-board sensors and local communication modules, two automata are capable of learning the best possible (lateral and longitudinal) actions to avoid collisions. This learning method is capable of …

Waterfall Lasers, Lee W. Casperson

Electrical and Computer Engineering Faculty Publications and Presentations

Laser concepts can be applied to a broad range of physical phenomena. One of the closest parallels occurs with the fluttering oscillations that are sometimes observed in the falling sheets of water associated with fountains, dams, and natural waterfalls. In many respects these fluid feedback oscillations are similar to the electromagnetic modes of typical lasers, and recognition of this similarity led to the interpretation of the waterfall behavior. Gain profiles for the waterfall oscillations are developed, and the relationship of experimental waterfall data to the laser-like models is considered in detail.

Radiation Imaging Operators Applied To The Detection Of Velocity And Density Contrast Boundaries, Md. Ishfaqur Raza, Richard E. Dubroff, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for imaging interfaces formed by simultaneous density and velocity contrasts in acoustic media is described. The procedure is based on the properties of radiation imaging operators - a class of linear differential operators parametrically dependent on the acoustic properties of the media. An example of this procedure is demonstrated through the use of numerical simulation. Results, in the form of interface images, are shown, assuming the bulk acoustic characteristics (velocity and density) on both sides of the interface are known.

Quantifying Emi Resulting From Finite-Impedance Reference Planes, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha, Cheung-Wei Lam, Lawrence Rubin

Electrical and Computer Engineering Faculty Research & Creative Works

Parasitic inductance in printed circuit board (PCB) geometries can detrimentally impact the electromagnetic interference(EMI) performance and signal integrity of high-speed digital designs. This paper identifies and quantifies the parameters that affect the inductance of some typical PCB geometries. Closed-form expressions are provided for estimating the inductances of simple trace and ground plane configurations.

Motion-Compensating Long-Term Memory Prediction, Thomas Wiegand, Xiaozheng Zhang, Bernd Girod

Electrical Engineering

Motion-compensating long-term memory prediction extends the spatial displacement utilized in block-based hybrid video coding by a variable time delay permitting the use of more frames than the previously decoded one for motion compensation. The long-term memory covers the decoded frames of some seconds at encoder and decoder. We investigate the influence of memory size in our motion compensation scheme and analyze the trade-off between the bit-rates spent for motion compensated prediction and residual coding. Simulation results are obtained by integrating long-term memory prediction into an H.263 codec. PSNR improvements up to 2 dB for the Foreman sequence and 1.5 dB …

Development Of The Base Station Transceiver Subsystem In The Cdma Mobile System, Dong-Wook Lee, Kisuk Yoo, Jin-Su Kim, Myoung Jin Kim, Jae-Hong Park

Electrical Engineering and Computer Science Faculty Publications

The base station transceiver subsystem (BTS) of the CDMA Mobile System is interfaced to mobile stations over the air and to the wired network through a packet switched interconnection network. The potential benefits of CDMA technology are achieved when the transmitter and the receiver are properly designed and implemented. The physical layer of the air interface at the base station is implemented with the CDMA ASICs and control circuits in the channel card of the BTS. We present the design perspectives and structural illustration of the BTS. Base station modem ASICs and their control to implement the CDMA receiver, baseband …

Selective Cvd Growth Of Diamond Crystals On Tungsten, Charles Randal Cole

Electrical & Computer Engineering Theses & Dissertations

Typical field emitters consist of sharp metal tips which usually have a short life due to erosion and contamination. To improve the performance of regular field emitters, diamond can be placed on the emitter tip. This is done by selectively growing diamond on tungsten tips using chemical vapor deposition (CVD) processing. Diamond exhibits negative electron affinity, so that electrons will be emitted by properly biasing the tip.

To obtain single crystal growth right at the tip, a cantilever controlled nucleation method was developed which worked better than other methods. Surface preparation was also important to the growth process. An oxide …

Stadium 501/Reliability Simulator For The Analysis Of Hot-Electron And Esd Induced Degradation In Non-Isothermal Device, Sungkwon Lee, Thomas J. Sanders

Electrical Engineering and Computer Science Faculty Publications

This paper addresses the integrated circuit industry needs for non-isothermal simulation in device reliability analysis, initial input factor sensitivity analysis and their software implementation. The key reliability issues are the hot-electron induced oxide damages and electro-static discharge (ESD) damages. The main purpose of this work is to provide a design aid tool to improve device reliability and performance. The reliability simulator developed in this work not only predicts designed device reliability, but also provides some information about the effect of manufacturing variations on reliability. This is accomplished by combining the statistical methodology with existing technology computer aided design (TCAD) tools. …

Time Enough - Consequences Of Human Microchip Implantation, Elaine M. Ramesh

RISK: Health, Safety & Environment (1990-2002)

Dr. Ramesh argues that microchip implantation is both possible and, for some purposes, desirable and suggests that now is the time to consider strategies for preventing potentially grievous intrusion into personal privacy.