Electrical and Electronics Commons^™

Cebus Demonstration System, Liang-Chuang Chen

Theses

A CEBus demonstration system is constructed and applied to aspects of home automation security. Two M68HC16Z1 evaluation boards are used as CEBus nodes. Two CEBus spread spectrum power line modems (SSC PLCEMS) interconnect the nodes. An SSC PLCEMS handles all spread spectrum signal generation and reception.

The application programs in the two boards are written in assembly language based upon CAL (Common Application Language), a CEBus standard.

The standard CEBus frame format and FCS (Frame Check Sequence) are implemented by software in the Data Link Layer. Encoding and decoding binary information into UST format are implemented in the Physical Layer. …

A Distributed Network Architecture For Video-On-Demand, Ge Dai

Theses

The objective of this thesis is to design a distributed network architecture that provides video - on - demand services to public subscribers. This architecture is proposed as an alternative to a centralized video service system. The latter system is currently being developed by Oracle Corporation and NCube Corporation.

A simulator is developed to compare the performance of both the distributed and centralized video server architectures. Moreover, an estimate of the cost of both systems is derived using current price data.

It is shown that the distributed video server architecture offers a better cost / performance trade-off than the centralized …

Artificial Dielectrics : Characteristics At Low And Microwave Frequencies, Nitish Agrawal

Theses

Artificial Dielectrics have been characterized using transmission line and s- parameter measurements. The complex dielectric constant and loss of graphite filled and non-poled piezoelectric-aggregate (Polyvinylidene Fluoride, PVDF) filled plastic (PMMA) has been characterized at low (1kHz-10kHz range, i.e., the VLF, very low frequency, range) and microwave frequencies. The average diameter diameter of graphite particles used was thirty microns. Measurements were performed on very fine graphite (one micron diameter grains) and 30 micron sized grains for comparison purposes. Fine grain graphite particles exhibited a, larger real dielectric constant, probably owing to a larger dipole effect. The dielectric constant characterization has also …

Influences Of Cardiac And Respiratory Parameters On Heart Rate Variability, Melissa Leifer

Theses

Heart rate variability is a result of variation in the activity of the sympathetic and parasympathetic nervous systems. Methods have been developed to determine the level of parasympathetic activity by observing the heart rate variability spectrum. Most of the previously published research uses only level of parasympathetic activity and respiratory rate to draw conclusions about the interactions of the autonomic nervous system with physiological parameters. In order to gain a complete understanding of the autonomic nervous system and the mechanisms responsible for heart rate variability, respiratory volume, cardiac variables and pulmonary variables need to be considered. In addition, amount of …

Motion Estimation Using Optical Flow Field, Jingning Pan

Dissertations

Over the last decade, many low-level vision algorithms have been devised for extracting depth from intensity images. Most of them are based on motion of the rigid observer. Translation and rotation are constants with respect to space coordinates. When multi-objects move and/or the objects change shape, the algorithms cannot be used.

In this dissertation, we develop a new robust framework for the determination of dense 3-D position and motion fields from a stereo image sequence. The framework is based on unified optical flow field (UOFF). In the UOFF approach, a four frame mode is used to compute six dense 3-D …

Estimation And Cancellation Of Friction In Control Systems, Sofia Mentzelopoulou

Dissertations

The research reported in this dissertation concerns the estimation and cancellation of friction in control systems. For purposes of analysis, the Coulomb friction model, the "extended" Coulomb friction model as well as dynamic friction models are used. In addition, for systems with multiple degrees-of-freedom, a general matrix representation of friction is presented.

For the design of the friction estimators, the theory of nonlinear observers is applied. In particular, for a system with multiple degrees-of-freedom, holonomic constraints, and multiple friction sources, three different observers are presented to estimate the friction force or torque. The first (Generalized Coulomb Friction Observer) is designed …

Investigation Of Paraelectric Ptl Thin Films Using Reactive Magnetron Sputtering, Hyun Hoo Kim

Dissertations

The study of methods to prepare paraelectric perovskite PLT (Pb_1-xLa_xTi_1-x/4O₃; x=0.28) thin films has been important because thin films of this high dielectric strength material are required to make high density capacitors for dynamic random access memory. In this research, paraelectric PLT thin films were prepared on multi-layer (Pt/Ti/SiO₂/Si) and MgO substrates in a unique way by the reactive magnetron sputtering method using a multi-component metal target. The individual control of each metal area on the sputtering target had considerable influence on the stoichiometry and electrical properties of the thin …

Heart Rate Variability Study Using Phase Response Curve, Peizhuan Zhang

Dissertations

A noninvasive phase resetting experiment on human subjects was investigated. The phase response curve was estimated and was used to demonstrate cardiac phase resetting due to a vagal input. The estimated running phase response curve showed that the cardiac cycle resetting depended on the time and the amplitude of the vagal stimulation. The phase response curve was then studied using time circle analysis, topological analysis and nonlinear dynamics analysis. Also phase entrainment and stimulus frequency dependence of the phase response were evaluated. Further, the Van Der Pol model, Generalized Additive model and Knight and Peskin's model were used to simulate …

Blind Detection In Channels With Intersymbol Interference, Raafat Edward Kamel

Dissertations

In high speed digital transmission over bandlimited channels, one of the principal impairments, besides additive white Gaussian noise, is intersymbol interference. For unknown channels, adaptive equalization is used to mitigate the interference. Different types of equalizers were proposed in the literature such as linear, decision feedback equalizers and maximum likelihood sequence estimation. The transmitter embeds sequences with the data regularly to help the equalizer adapt to the unknown channel parameters.

It is not always appropriate or feasible to send training sequences; in such cases, self adaptive or blind equalizers are used. The past ten years have witnessed an interest in …

Deterministic And Adaptive Routing Algorithms For Mesh-Connected Computers, Yikui Cai

Theses

The two-dimensional mesh topology has been widely used in many multicomputer systems, such as the AMETEK Series 2010, Illiac IV, MPP, DAP, MasPar MP-1 and Intel Paragon. Its major advantages are its excellent scalability and simplicity. New generation multicomputer uses a switching technique called wormhole routing. The essential idea of wormhole routing is to advance a packet directly from incoming to outgoing channel without sorting it, as soon as enough information has been received in the packet header to select the outgoing channel. It has advantages of low latency and low error rate. The problems addressed by this thesis are …

Performance Analysis Of The "Fiber Distributed Data Interface (Fddi) Network" Using Petri Nets And Spnp Software Package, Savvas Eteoclis Christodoulou

Theses

The main purpose of this thesis is to model a "Fiber Distributed Data Interface" (FDDI) Network using Petri Nets, and to analyze its performance with the help of the SPNP software package. The verification of a communication protocol, by modeling it as a discrete-event system using Petri Nets is a new approach.

The correlation between the throughput rate, voice and data throughput, and the parameters of the system, such as the network load and the network speed are investigated. An overview of the "Fiber Distributed Data Interface" is provided, along with its network protocol and the limitations of its operating …

Characterization Of Lightning Induced Voltages On Overhead Power Lines, Wen-Ta Hsiao

Theses

The transient voltage surge caused by lightning is the major source contributed to the disturbance on power systems. The calculation of induced voltages, which is the propagated voltage surge on overhead power lines due to indirect lightning strokes, has been the subject of theoretical and experimental studies. The objective of this research is to develop a comprehensive numerical method to study the induced voltages on an overhead power line caused by a lightning return stroke with arbitrary shapes, for examples inclined lightning, zigzag lightning, etc.

A finite-length lightning channel of any direction in 3-D space has been modelled and closed-form …

Fast Adaptive Algorithms For Signal Separation, Robert A. Manzo

Theses

LMS and RLS type algorithms are suggested for decorrelation of multi-channel systems outputs. These algorithms act as signal separators when applied to unknown linear combinations of the inputs. The performance of the suggested algorithms is compared with that of the conventional LMS and RLS algorithms that minimize the mean square error. It. is shown that the correlation matrix eigenvalue spread associated with the LMS decorrelator is always smaller than the eigenvalue spread corresponding to the conventional LMS. resulting in faster convergence speed for the decorrelator. A new RLS type decorrelator algorithm is suggested. The RLS decorrelator is shown to be …

Motion Compensation Using Correlation-Feedback, Zebiba Shifa

Theses

Motion compensation is widely used for exploiting temporal redundancies in the coding of image sequences. Accurate estimation of motion information in image sequences is important in motion-compensated coding. Different approaches have been used to estimate motion to obtain the motion-compensated frame difference signal.

This work uses the correlation-feedback approach to estimate the velocity or the optic flow of the moving image pixel. After the motion of the pixel is estimated. the motion-compensated frame difference signal is found by subtracting the current. frame from the predicted frame.

This correlation-feedback approach estimates the true motion vector of moving image accurately. Consequently, the …

Narrow-Band Interference Rejection In Spread Spectrum Using An Eigen Analysis Based Approach, Aparna Vadhri

Theses

A new adaptive technique is suggested for rejecting narrow-band interferences in spread spectrum communications. When data is coded using a pseudo-noise code, the received signal consists of a wide-band signal with almost white spectral properties, thermal noise, and correlated narrow-band interferences. A new approach is proposed which exploits the statistical properties of the received signal via eigenanalysis of the received data. While the energy of the wide-band signal is distributed over all the eigenvalues of the signal autocorrelation matrix, the energy of the interference is concentrated in a few large eigenvalues. Hence, the eigenvectors corresponding to the large eigenvalues are …

Programmable Microstrip Dipole Antenna Design, Jing Zhu

Theses

The narrow bandwidth of microstrip dipole antennas is a major limitation for many applications. A method to increase the microstrip dipole antenna bandwidth is illustrated in this thesis. The proposed method utilizes micromechanical actuators to adjust the electrical length of the dipole antenna. The length change is realized by the activities of several microactuators arranged on both arms of the antenna. The radiation pattern and input impedance, as well as the microactuator mechanisms are detailed in this thesis. A programmable microstrip dipole antenna including the microactuators has been designed with the feedline taken into consideration. The fabrication techniques for this …

A Novel Beam-Assisted Thickness Measurement Technique For Nanostructures, Luis Manual Casas

Theses

A novel method for measuring thickness of thin films has been developed. This method is straightforward, quickly accomplished, and offers resolution of device layers approaching that given by transmission electron microscopy. Ion beam bombardment of a multi-layer structure forms a crater in which the crater sidewalls are beveled at a very shallow angle, revealing various layers within the sample at a high degree of magnification. Beveled film thicknesses are measured by scanning Auger electron spectroscopy. Depth profilometry is used to measure the shallow beveling angle. Through knowledge of the beveled layer thickness and the bevel angle, actual film thicknesses are …

Simulation Analysis Of Fddi Network Using Network Ii.5 Software Package, Anastassis A. Lazarides

Theses

In recent years, one of the most exciting advances in media has been the use of fiber optics in LANs. The bandwidth provided by Fiber Optic Technology has drastically increased the number of new applications that can be supported by communication networks. In order to support a variety of services, in 1986, the American National Standard Institute (ANSI) Accredited Standards Committee (ASC) X3, and the ASC X3T9.5 Task Group developed a new standard; the Fiber Distributed Data Interface (FDDI) [1]. This is a high speed (100 Mbps) optical communication network based on a token passing mode of operation. The Medium …

Multi-Disk Subsystem Organizations For Very Large Databases, Zhiyi Huang

Theses

This thesis investigates efficient mappings of very large databases with non-uniform access to its data. to a. multi-disk subsystem.

Two algorithms are developed to distribute the database across multiple disks, possibly with replication, in order to minimize latency and maximize throughput. These algorithms are compared with respect to the amount of replication overhead incurred to achieve desired throughput.

A simulator is developed to simulate these two mapping algorithms and investigate the efficiency of these two mappings.

Interference Cancellation By Time Adjustable Sampling, Josko Zec

Theses

The problem of improving the frequency response of linear arrays is addressed in this thesis. The improvement is measured in the level of rejection of the undesired sources. A new, simple, and practical method is suggested. It is based on adjusting the sampling time in selected channels. Interference cancellation for finite bandwidth signals is accomplished only at, or close to, the carrier frequency. Wideband cancellation requires additional hardware and computational complexity. Conventional way of the wideband interference cancellation utilizes tapped delay line adaptive filters in each channel.

The Time Adjustable Sampling (TAS) method achieves a part of the tapped delay …

On Issues Of Equalization With The Decorrelation Algorithm : Fast Converging Structures And Finite-Precision, Andrew James Bateman

Theses

To increase the rate of convergence of the blind, adaptive, decision feedback equalizer based on the decorrelation criterion, structures have been proposed which dramatically increase the complexity of the equalizer. The complexity of an algorithm has a direct bearing on the cost of implementing the algorithm in either hardware or software. In this thesis, more computationally efficient structures, based on the fast transversal filter and lattice algorithms, are proposed for the decorrelation algorithm which maintain the high rate of convergence of the more complex algorithms. Furthermore, the performance of the decorrelation algorithm in a finite-precision environment will be studied and …

Human Visual System Modelling : Analysis Of Evoked Potential Dynamics, Zongqi Hu

Dissertations

The visual evoked potential (VEP) reflects the electrical activity in the cerebral cortex due to visual stimulation. It contains information on signal processing in the visual pathways from the retina, through the lateral geniculate nucleus (LGN) to the cortical level. Although the VEP is generated by various sources in the multi-layer neural network, the functions of some neuronal mechanisms and the transfer characteristics of particular pathways can be revealed and analyzed by use of carefully designed stimuli (Zemon & Ratliff, 1984; Zemon, Victor & Ratliff, 1986). This dissertation focuses on studies of the visual evoked potential as a composite of …

Coordination Of Time-Overcurrent Relays For High-Speed Power Line Protection, Nicos Charalambous

Theses

A properly coordinated protection system is essential to ensure that an electricity distribution network can operate within its requirements, regarding the safety of a power system. Automatic operation is necessary to isolate faults on a power system in a minimum time. The study of time coordination of relays suggests improved ways of power line protection. The protection must be sensitive enough to operate when a fault occurs under minimum fault conditions, yet be stable enough not to operate when its associated equipment is carrying the maximum rated current, which may be a short-time value. A power system is used as …

Fabrication And Characterization Of Wsi2/P-Si And Tasi2/P-Si Devices, Anitha Kodali

Theses

Thin films Silicides of Tungsten and Tantalum have become very important for IC manufacturing. W and TaSi₂ films were deposited on silicon substrates by CVD and Co-sputtering techniques respectively. These films have been characterized using current-voltage technique. The analysis of the obtained experimental measurements has been performed in the light of Schottky-Mott theory. The effects of annealing were studied using Rapid Thermal Processing technique in the temperature range of 500 to 700°C, in nitrogen atmosphere at a constant pressure of 5x10^-6 ton for a duration of 30 seconds.The increase in annealing temperature resulted in the formation of ohmic …

A Graphical Tool For Timed Petri Nets Using Object Oriented Programming, Baopu Liu

Theses

The objective of this effort is to develop a computer tool for drawing, editing and simulating Timed Petri Nets using object oriented programming. The developed C++ based Timed Petri Net Simulation Tool, TimedPNT, is capable of simulating discrete systems with both deterministic and stochastic delays. Preselection is used for conflict resolution. Performance and utilization results are automatically collected. XView™ Toolkit is used for building the TimedPNT's interactive graphical interface in compliance with AT&T's OPENLOOK® standard on a SunSparc™ IPX running SunOSTM 4.1.2. Compliance with the X Window standard makes the developed tool portable to other X Window based systems.

Investigation Of Reduced Hypercube (Rh) Networks : Embedding And Routing Capabilities, Michalis A. Sideras

Theses

The choice of a topology for the interconnection of resources in a distributed-memory parallel computing system is a major design decision. The direct binary hypercube has been widely used for this purpose due to its low diameter and its ability to efficiently emulate other important structures. The aforementioned strong properties of the hypercube come at the cost of high VLSI complexity due to the increase in the number of communication ports and channels per node with an increase in the total number of nodes. The reduced hypercube (RH) topology, which is obtained by a uniform reduction in the number of …

Measurement Of Heart Rate Variability Using Correlation Dimension And Entropy, Su Zhang

Theses

Heart rate variability regulation is controlled by the autonomic nervous system. Disorders of the autonomic nervous system may cause the loss of heart rate variability. Two new approaches, correlation dimension and entropy, based on ideas from nonlinear dynamics, have been applied to studying heart rate variability. The correlation dimension measures the extent of correlation between the data points. The entropy measures the amount of information needed to specify the state of a system. The interbeat interval signal (1BI) from eighteen subjects (nine normal controls and nine patients with Chronic Fatigue Syndrome (CFS) ) have been analyzed and compared. The results …

Design And Implementation Of Fuzzy Logic Controller For A Process Control Application, Sujit S. Nerurkar

Theses

Many industrial applications of fuzzy logic control have been reported. This thesis studies and reports the problems associated with the Heat-exchanger temperature control via conventional PID control implemented with Programmable Logic Controllers (PLC) and provides an example of design and implementation of fuzzy logic controllers (FLC's) for a Heat exchanger in a Water for Injection (WFI) system.

After a basic FLC was designed and tested, it is shown how its rule base evolved to achieve superior performance by utilizing additional low-cost sensing information in the process and its environment. A method for the implementation of FLC's into the existing PLC …

Application Of The Wavelet Transform To Biomedical Signals, Karl O. Hauck

Theses

The basic concepts and fundamentals of the wavelet signal representation were examined. The orthonormal wavelet was selected for this project after being compared to various types of wavelets. The orthonormal wavelet was chosen due to the equal time and frequency resolution exhibited in the wavelet coefficients. Programs were written in Matlab to implement the orthonormal wavelet in developing wavelet coefficients for a given signal. The programs include the conditions for an orthonormal wavelet in and which produce the wavelet filters g(n) and h(n). The wavelet filters were then incorporated into another program that applied Mallat's multiresolution algorithm for a given …

Transient Behavior Of An Adaptive Synchronous Cdma Receiver, Bin Zhu

Theses

A steepest descent algorithm is used to update the adaptive weights of a two-stage synchronous Code-Division Multiple-Access (CDMA) receiver that was proposed recently. An issue of the adaptive CDMA system - the convergence and stability property of the receiver is investigated in this thesis.

This adaptive synchronous CDMA receiver uses a decorrelator at the first stage and adopts a neural network which acts as an interference canceler at the second stage. It can achieve near-optimum performance. Furthermore, its computational complexity is just a square function of the number of users. The only requirement is the knowledge of the users' signature …