Electrical and Electronics Commons^™

The Theory Of Bootstrapped Algorithms And Their Applications To Cross Polarization Interference Cancelation, Abdulkadir Dinc

Dissertations

Dual-polarized transmission has become an important method for frequency re-use, particularly in satellite and microwave radio communication. Nevertheless, cross-polarization interference, which is inherent to this method, may cause degradation in system performance.

Different canceler [sic] structures have been proposed to mitigate the effect of cross-polarization. Among these are the diagonalizer, the least mean square (LMS) canceler [sic] and the bootstrapped cancelers [sic]. Bootstrapped canceler [sic] schemes have been proposed and implemented in different applications, such as satellites, tactical communications, and quadrature amplitude madulation [sic] (QAM) dual polarized microwave radio. Nevertheless, no attempt was made in the past to quantify the …

3-D Structure Recovery Using Unified Optical Flow Field Approach, Anees Ahmad

Theses

Recovery of the 3-D structure that is characterized by an N^th order factorable and/or non-factorable polynomial equation is studied in this thesis. Analytical tools have been employed to analyze and solve the problem. The solution is based on the direct method, which is derived from the unified optical flow field, which, in turn, is an extension of optical flow to spatial image sequences. Least squares formulation has been employed for optimum estimation. The method used does not require the establishment of point to point correspondence, nor the estimation of the optical flow, as an intermediate step.

The theoretical results …

Application Of Non-Imaging Optical Inspection To The Detection Of Pinhole Defects In Latex Condoms, Paul Micha Gelencser

Theses

An optical technique was demonstrated for the detection of pinhole defects in latex condoms. To evaluate the optical inspection concept, a prototype inspection apparatus was constructed. In order to maximize contrast between pinhole transmitted signal and optical signal transmitted through the latex condom material, ultraviolet (u.v.) light of wavelength 253nm has been used. This inspection was performed during rotation of the condom, with the light source inside the condom and the photomultiplier photodetector outside. The form on which the condoms were mounted was made of quartz in order to allow the u.v. light to be transmitted through it.

Background signal …

The Design And Testing Of A Personal Computer Controlled Scanning Acoustic Microscope For Orthopaedic Surgical Applications, Hubert Heinrich Berndt

Theses

This thesis describes scanning acoustic microscopy and ultrasonic image processing to characterize and evaluate materials of known properties, as well as novel materials. This work describes the assembly and testing of a PC based device for nondestructive evaluation of bone materials for usage in orthopaedics research. It includes the identification of some hardware problems and their solution, and it also describes different image processing techniques that have been developed and applied in this work. In a growing number of disciplines it has been discovered that an acoustic microscope can provide new information, especially about the elastic properties of specimens and …

Synthesis And Characterization Of Lpcvd Silicon Carbide Thin Films For X-Ray Lithography, Mahalingam Bhaskaran

Theses

Amorphous silicon carbide thin films were fabricated using low pressure chemical deposition method with a single liquid precursor, di tertiary butyl silane. The films were deposited for a temperature range of 500-850°C and at different pressures ranging from 0.05 to 1 torr. The growth rate of the films deposited at constant pressure of 0.2 torr with a flow rate of 60 sccm, was found to follow an Arrehenius Behavior in the temperature range of 600 - 675°C, yielding an activation energy of 32.5 k cal mol^-1 . IR spectroscopic study showed an absorption peak centered at 780 cm^{-1 …}

Electroretinogram Modeling : Parameter Identification And Intensity-Response Function Fits, Juan J. Castro

Theses

Electroretinography testing provides many useful techniques for clinical diagnosis of the visual system. However, the interpretation of the electroretinogram data involves a great amount of subjectivity. The use of mathematical models and parameter estimation techniques to fit the electroretinogram data supply a non-subjective and more standard way for analysis of the electroretinogram data. Mathematical models provide a way of summarizing the information enclosed in the raw electroretinogram response into a small set of parameters that define the response.

This thesis presents a mathematical model for the electroretinogram response due to light stimuli. It also provides a non-subjective method for obtaining …

A Mouse-Driven Interface For Androx Ics-400, Chin-Tien Chen

Theses

A mouse-driven interface is extremely useful for software performing image processing tasks. This thesis describes an implementation of a mouse-driven interface for the Androx ICS-400 image processing board. The Androx board is housed in a Sun 4/330 running a UNIX-based operating system. The main goal of this interface is to provide a consistent and friendly user interface for image processing tasks and integrating the Sun window libraries with the Androx libraries. Various image processing tasks, such as gray scale and binary morphological operations, histogram, thresholding, filtering, spot, logical operations, arithmetic operations, zooming, scrolling, rank and image acquisition are implemented in …

The Bandwidth Allocation Of Atm Control By Neural Networks, Jin-Syan Chou

Theses

In this thesis, we develop a neural network method based on Adaptive Resonance Theory to train and control the optimum bandwidth allocation of ATM network. In Broadband Integrated Service Digital Network (BISDN), the Asynchronous Transfer Mode (ATM) is already adopted as the transfer facility by CCITT. ATM is a high-bandwidth, low- delay, fast-packet switching and multiplexing technique. Using ATM technique, we can flexibly rearrange the network and reassign the bandwidth to meet the requirement of all types of services. As an effective optimization method, Genetic Algorithm (GA) is applied to implement the bandwidth allocation of ATM. Then, we use Adaptive …

Androx Implementation Of Nonlinear Filter, Keh-Chao Chu

Theses

Nonlinear filters, such as morphological operations, play an important role in image processing. Several software implementations of nonlinear filters are presented in this thesis. There may exist more than one method to implement a specific operation. The methods used in this thesis are chosen to be most suited for the machine used according to its structure. These most suited methods are also generally best for software implementations on other machines as well. The machine used here is the Androx image computing workstation.

Modeling Of Vacuum Microelectronic Lateral And Vertical Devices, Qiong Gui

Theses

Vertical and lateral configurations of the vacuum microelectronic device have been modeled using the simulation tools. Both cone and ridge cathode structures are used. Simulation results are compared with experimental data where available. These device structures include cathode, extraction grid, anode, and deflectors. The electric field at the tip of the cathode has been calculated for tip radius as small as 0.1nm. The model used takes into account the effect of potential on all electrodes on the E-field at the cathode tip. Also the effect of cathode geometry on the E-field is detailed.

Static characteristics are based on a new …

Representing Tolerances In A Geometric Modeller, Chih-Tsung Huang

Theses

Current geometric modeller contains dimension information only. This thesis describes how tolerance can be added to a geometric modeller. The modeller is based on a hybrid design of the Constructive Solid Geometry (CSG) scheme and Boundary Representation (B-Rep). Various tolerances based on the ANSI standard are considered.

The Neural Network Based Control System For Dynamic Channel Allocation In Pcn Communications, Ching-Yao Huang

Theses

A neural network based control system (NNCS) is adopted in this paper to conduct the channel allocation task in the personal communication networks (PCN). Binary adaptive resonance theory (ART-1) that was modified for pattern matching and provided the corresponding responses is selected as the basic algorithm for the system. Digital portable radio technology can provide reliable access to high quality wireless service for many users. Low power transmission requirement and small cell size configuration that can support more users and diverse services than cellular radio system are the attractive attributes of PCN. Assigning multiple time slots to a user in …

Automatic Infrared And Visual Inspection Of Solder Joints On Pcbs, Jiang Huang

Theses

This thesis reports the research results of automatic inspection of solder joints on printed circuit boards (PCBs). The previous work on this regard has been advanced significantly in the following three aspects. With the application of some microlens and the principle of geometric optics solder joints of real size are inspected in this work instead of larger simulation solder joints in the previous work. A new set of features is formulated and used for infrared inspection. Consequently, better results have been achieved in this work.

Reasonably good results demonstrate the capability of infrared inspection of solder joints on PCBs. Once …

Direct Recovering Of Composite Surface Using Uoff, Zhesheng Huang

Theses

The research work reported in the thesis is motivated by the problem raised in the computer vision area. It utilizes direct method to recover surface structure of objects in 3-D space from a pair of stereo images. The direct method, compared with optical flow-based approach and feature-based approach, is robust and computationally efficient. However it can only recover planar surface structure so far. A new approach to recover structure from a pair of stereo images based on unified optical flow field (UOFF) is developed recently. It can recover curved surface structure.

In this thesis, the problem of recovering surface structure …

Brushless Dc Motor Speed Control System With Saturation Nonlinearity, Khawja M. Kamal

Theses

A study of a three-phase, pulse-width modulated, velocity controlled brushless DC motor speed control system is presented. Previous works on brushless DC drive systems could not explain global instability, due to linear approximations. A complete three-phase system model is presented here, along with a simplified single-phase model, which is similar to a conventional DC motor model. The models incorporate saturation nonlinearity. The brushless DC drive system is analyzed and simulated. Special emphasis is laid on the study of the limit-cycle phenomenon, due to saturation nonlinearity. Global instability is accounted for and relevant parameter regions are established for global stability. The …

Workstation Allocation Schemes For Response Time Improvement In A Multiserver Pc Lan, Asit V. Merchant

Theses

Microcomputer Local Area Networks have recently become quite popular. Higher demand in term of number of users who contribute a variable amount of load has led to Multiple File servers in a LAN. As a result of variable load, response time at workstations differ significantly depending not only on total load on the network but also on workstation distribution across servers. The goal of this study is to develop schemes to keep response time as low as possible and constant among workstations. This study is based on minimizing response time and containing it or keeping it constant by distributing workstations …

A Comparative Study Of Image Coding Techniques : Filter Banks Vs. Discrete Cosine Transform, Hosam Fawzi Mutlag

Theses

Subband coding of still image frames using Binomial PR-QMF has been presented in this thesis. Simulation results have shown that the performance of subband coding using a low complexity coder is practically the same as the performance of the industry standard (8 x 8) DCT based image coder.

A low bit rate adaptive video coding technique is also introduced in this thesis. The redundancy within adjacent video frames is exploited by motion compensated interframe prediction. The Motion Compensated Frame Difference (MCFD) signals are filtered by employing Binomial PR-QMF structure into four subbands. Then, the subbands are quantized using an efficient …

Minimized Test Patterns For Sequential Logic, Chetan Patel

Theses

This thesis presents a novel algorithmic approach which can be used to reduce the total test pattern lengths for testing a sequential logic circuit. Test generation for sequential circuits has long been recognized as a difficult task. Several approaches have been made in the past to solve the problems of test generation stage for sequential circuits but they were either an extension of the classical D-algorithm or based on the random techniques. When number of states of the sequential circuit is larger and the test demands long input sequences, they can be quite ineffective for the test generation. The STALLION …

Synthesis And Characterization Of Boron Nitride Masks For X-Ray Lithography, Venkat Paturi

Theses

Boron nitride thin films were deposited on silicon and fused quartz substrates by low pressure chemical vapor deposition using liquid precursor source consisting of Triethyl amine borane complex over a temperature range of 600-900°C. In the range of 600-800°C, the deposition rate, measured at a constant pressure of 0.35 Torr and flow rate of 30 sccm, was observed to follow an Arrhenius behavior yielding an activation energy of 11 kcal/mol. In the temperature range of 800-900°C, the addition of ammonia to Triethylamineborane complex produced films that are stoichiometric, as estimated by RBS measurements, and hydrogen free as determined by Infrared …

Analysis And Implementation Of A Navigation System Using Vanishing Points In A Generalized Environment, Rolf Schuster

Theses

The development of accurate sensors is of crucial importance in navigation of mobile autonomous robots. The following master's thesis analyzes the use of vanishing points for robot navigation. Parallel lines in the environment of the robot are used to compute vanishing points which serve as a reference for guiding a robot. To accomplish the navigation tasks, three subtasks are to be performed: detection of straight lines, computation of vanishing points, and robot navigation with vanishing points.

An edge detection algorithm is presented that combines Sobel and Laplacian of Gaussian operators. The algorithm preserves the precision of the Laplacian of Gaussian …

Connected Component Labelling On A Pair Of Parallel Systems, Imran Shahid

Theses

Hypercubes and meshes are of the most successful parallel processing structures and are widely used in image processing applications. The mesh is a natural multiprocessor architecture for image processing because an N x N image can be directly mapped onto a mesh of N x N PEs (processing elements), holding each PE responsible for one pixel, with neighboring PEs responsible for neighboring pixels. Thus, local operations can be performed on the image, or local image features can be detected in parallel, with each processor simultaneously accessing its neighbor and computing the appropriate function for its neighborhood. Meshes and several other …

Tisi2/N+/P Silicon Junction Formation By Ion Implantation Through Metal Technique, Ying Wu

Theses

Experimental analysis, modeling and simulation of the formation and electrical characterization of TiSi₂/n⁺/p-Si shallow junctions are presented here. The formation of shallow n⁺-p junction, by ion implantation of As⁺ through Ti films evaporated on p-Si substrates followed by Rapid Thermal Annealing ( RTA ) and conventional furnace annealing has been performed in these experiments. Structural techniques such as Secondary Ion Mass Spectroscopy ( SIMS ) and Rutherford Backscattering spectroscopy ( RBS ) experiments have been employed to characterize the devices, and RUMP simulator was used to analyze and interpret the RBS data. Current-voltage …

Novel Artificial Dielectric Plannar Waveguides, Jialing Yang

Theses

An artificial dielectric is a composite material consisting of a dielectric with a large number of conducting particles arranged in a three-dimensional pattern. The particle dimensions are smaller than the optical wavelength of interest. In this thesis, the theoretical and experimental results of some novel artifical dielectric planar waveguide structures are presented. By comparing near field intensity profile measurements from various waveguide structures, we have shown that by adding small clusters of the conductor material into the waveguide we can tailor the mode profile of the waveguide. Also, we were able to fabricate waveguides on a substrate with relatively higher …

A New Approach To Motion Analysis From A Sequence Of Stereo Images, Lin Zhou

Theses

A new approach to motion analysis from a sequence of stereo images is presented in this thesis. Based on a four-frame model, a new concept of unified optical flow field has been developed recently [3]. It is a generalization of the optical flow in stereo imagery. A set of fundamental equations is established to characterize the unified optical flow field. Another set of equations is then derived from which 3-D motion can be reconstructed via the use of the field quantities of the unified optical flow field. In this thesis, the implementation of the approach is conducted. The simulation and …

Bad Data Identification In Power Systems, Shichun Zou

Theses

Two classes of bad data (BD) identification methods in power system state estimation are studied.

The first class is the perturbation method. In this method, the obtained measurements are perturbed a few times. Each time a state is obtained from which measurement corrections are calculated. The statistics of the corrections corresponding to a BD are different from those corresponding to a healthy data. The method uses those differences for identification purposes.

The effectiveness of different indicators is studied. These include the normalized residual, the weighted residual, and residuals incorporating the statistics of the corrections.

The success rate of using the …

Performance Analysis Of Symbol Timing Recovery Circuits Employed In Digital Communications Systems, Elisha Yegal Bar-Ness

Theses

An analytical approach is presented for the jitter performance of a timing recovery circuit consisting of a prefilter, a zero-memory nonlinear device, and a narrow band postfilter tuned to the pulse repetition frequency. Assuming first a squarer type of nonlinearity, analytical expressions for the rms jitter in the timing wave are obtained as a function of the pre and post filtering characteristics. These expressions are suitable for judging the case where the baseband signal is bandlimited. Also for some specific examples, the jitter performance of this kind of STR circuit is evaluated.

Secondly, a general type of nonlinerity is assumed, …

Multistage Interconnection Networks : Improved Routing Algorithms And Fault Tolerance, Kuo-Yu Chen

Theses

Multistage interconnection networks for use by multiprocessor systems are optimal in terms of the number of switching element, but the routing algorithms used to set up these networks are suboptimal in terms of time. The network set-up time and reliability are the major factors to affect the performance of multistage interconnection networks. This work improves routing on Benes and Clos networks as well as the fault tolerant capability. The permutation representation is examined as well as the Clos and Benes networks. A modified edge coloring algorithm is applied to the regular bipartite multigraph which represents a Clos network. The looping …

Task Scheduling For Fms Based On Genetic Algorithm, Hung-Yuan Li

Theses

A Flexible Manufacturing System (FMS) consisting of p automated guided vehicles (AGV's), m workstations and n tasks is studied. The main problem investigated in this thesis is to find an optimal or suboptimal task scheduling for p AGV's among m workstations to complete n tasks.

An efficient approach based on genetic algorithms has been designed and implemented to solve the problem of task scheduling for a FMS. Near-optimal, or even optimal, task scheduling is accomplished by genetic algorithms. Simulation results on the algorithm are also discussed.

Performance Evaluation And Comparison Of Ordinary, Adaptive And Exhaustive Services In The Token Ring Network, Hong Wang

Theses

Ordinary service and exhaustive service are two major alternatives of scheduling policies considered in providing access to token ring networks. Results to date have shown that exhaustive service results in more delay to lightly loaded stations in asymmetric traffic while ordinary service wastes time in circulating the token after each transmission. This work presents a new token passing protocol, called adaptive service, in which the token holding time is dynamically changing; in this way, it provides a fair compromise between exhaustive and ordinary service. The simulation results show that in asymmetric traffic, adaptive service gives improvement on the local delay …

Performance Evaluation In Terms Of Congestion And Flow Control Of Interconnected Token Ring Local Area Networks, Muhammad Salim Raza

Theses

In an interconnected network, if user demands are allowed to exceed the system capacity, unpleasant congestion effects occur which rapidly neutralize the delay and efficiency advantages. Congestion can be eliminated by using an appropriate set of traffic monitoring and control procedures called flow control procedures. This thesis first investigates the major technical concepts underlying the token-ring technology; performance and flow control issues and then gives an approximate analytical solution in terms of mean end-toned delay in a system of token-ring local area network interconnected through bridges. The analytical solution is based on an approximation of the mean end-to-end delay in …