Electrical and Computer Engineering Commons^™

Advanced Controller Design Using Neural Networks For Nonlinear Dynamic Systems With Application To Micro/Nano Robotics, Qinmin Yang

Doctoral Dissertations

"The dissertation focuses on neural network (NN) control designs for nonlinear systems with application to micro/nano robotic. Critical problems in nano scale including thermal drift are also addressed"--Abstract, page iv.

Simple And Efficient Solutions To The Problems Associated With Acoustic Echo Cancellation, Asif Iqbal Mohammad

Doctoral Dissertations

"This dissertation is a collection of papers that addresses several important problems associated with acoustic/line echo cancellation (AEC/LEC), specifically double-talk and echo-path change detection. A double-talk detector is used to freeze AEC filter's adaptation during periods of near-end speech. This dissertation presents three different novel double-talk detection schemes. Simulations demonstrate the efficiency of the proposed algorithms"--Abstract, page iii.

Bga Footprints Modeling And Physics Based Via Models Validation For Power And Signal Integrity Applications, Giuseppe Selli

Doctoral Dissertations

"Modeling and simulating the multi-scale nature of a power distribution network (PDN) is essential to ensure the correct functioning of the devices connected to it. Simple parallel-plate sections constitute the core of these PDN geometries, together with sections where a large number of holes and vias are present, as in the case of a BGA footprint. Employing a divide-and-conquer approach allows for the modeling of these geometries separately, i.e., 3-D full wave solvers for the sections with holes and vias, and a cavity model approach, for the simple parallel-plate structures. Also, equivalent circuit models can be obtained for time-domain and …

Mobile Array Designs With Anserlin Antennas And Efficient, Wide-Band Peec Models For Interconnect And Power Distribution Network Analysis, Michael A. Cracraft

Doctoral Dissertations

"A mobile, wide-band antenna system has been developed around the ANSERLIN antenna element and a 3-dB splitter design. The size of the antenna elements was reduced over previous versions by introducing dielectric substrates. Additionally, new variations of the antenna were designed to influence radiation characteristics. To further reduce the number of components in the array, a very low profile splitter was designed and mounted below one of the antenna elements, doubling as the return plane for the antenna. The partial-element equivalent circuit (PEEC) method has been used for 3D interconnect analysis and numerous other applications. Being based on the same …

Data Fusion Techniques For Health Monitoring Of Aging Aircraft And Skin Cancer Detection, Kapil Gupta

Doctoral Dissertations

"Data fusion is generally practiced to enhance decision or inference making capability. Sensor and information source data may often be corrupted by noise or other factors. Data fusion can be used to improve sensor and/or information source data quality and reliability and improve detection accuracy. There are several types of data fusion, including raw data level, feature level, and decision level.

This work presents the investigation and development of image and signal processing, computational intelligence, fuzzy logic, and statistical techniques for different types of data fusion for a varied range of applications. Raw data and decision level fusion approaches are …

Design And Development Of Triangular, Spiral, And Fractal Antennas For Radio Frequency Identification Tags, Jeevan K. Vemagiri

Doctoral Dissertations

This dissertation reports on the design and development of three compact, non-meandered microstrip patch antennas for ultra high frequency (UHF) radio frequency identification (RFID) applications. The monopole antennas considered in this work are an inset-fed triangular antenna, one arm Archimedes spiral antenna and a Half-Sierpinski fractal antenna. These antennas with small length to width ratios (< 2/1), can be the preferred choice, in the tagging of small size consumer end products, over the ubiquitous meandered dipole antenna (length/width > 5/1), which is often the antenna of choice, due to its high gain for UHF RFID applications. The lengths and widths of all three antennas are less than 5.5 cm. Earlier reports of planar antennas for RFID applications in the UHF range have lengths …

Delay Line Based Passive Radio Frequency Identification Tags, Aravind Chamarti

Doctoral Dissertations

This work describes the concept, design, fabrication, and characterization of delay-based radio frequency identification (RFID) tags and RFID-based sensor tags, representing a novel RFID technology. The presented delay-based RFID concept is based on the LC-delay-line and transmission-delay-line based approaches. The proposed concept allows the realization of RFIDs and RFID-based sensor tags at any allowed radio frequency, with the limitation of realizing delay elements capable of producing required delays. The RFID configurations presented in this work are for operation at 915 MHz. Simulations are used to design and optimize components and devices that constitute the tags, and to integrate them to …

Development And Applications Of Inkjet Printed Conducting Polymer Micro-Rings, Rajneek K. Khillan

Doctoral Dissertations

A drying sessile drop moves the solute particles to the periphery where they get deposited in the form of a ring. This phenomenon is prevalent even with micro drops falling at high velocity from a piezo-actuator based inkjet printer. In polymer microelectronic field, this phenomenon is a major challenge for fabricating devices using inkjet printing. We exploited this problem and applied it for various novel applications in the field of polymer microelectronics.

Various dispensing techniques and temperature variations for micro-drop printing were used for modifying the micro-drops in such a way that the periphery of the micro-ring holds most of …

Nanodot-Based Organic Memory Devices, Zhengchun Liu

Doctoral Dissertations

In this study, resistor-type, diode-type, and transistor-type organic memory devices were investigated, aiming at the low-cost plastic integrated circuit applications. A series of solution-processing techniques including spin-coating, inkjet printing, and self-assembly were employed to fabricate these devices.

The organic resistive memory device is based on a novel molecular complex film composed of tetracyanoquinodimethane (TCNQ) and a soluble methanofullerene derivative [6,6]-phenyl C61-butyric acid methyl ester (PCBM). It has an Al/molecules/Al sandwich structure. The molecular layer was formed by spin-coating technique instead of expensive vacuum deposition method. The current-voltage characteristics show that the device switches from the initial 'low' conduction state to …

Design And Development Of Poly -(3 -Hexylthiophene) Field Effect Transistors, Fengliang Xue

Doctoral Dissertations

Organic field effect transistors (OFETs) with poly(3-hexylthiophene) (P3HT) as the active layer are developed and studied. The device characteristics are significantly affected by source/drain contact resistance, and P3HT-SiO 2 interface and the traps. These results are verified by the numerical device simulations. The temperature dependence of device mobility is studied, which indicates that the carrier transport is either heat-assisted or heat-limited at different temperature ranges. The on/off ratio and threshold voltage are found to be dependent on the temperature. Hysteresis effect due to gate electric stress is investigated. The silanol groups present at the SiO2 surface are thought to be …

Study On Poly[2-Methoxy-5-(2'-Ethylhexyloxy)-1,4-Phenylenevinylene] Polymer Based Photodetectors, Difei Qi

Doctoral Dissertations

This thesis is dedicated to the development of novel and efficient polymer photodetectors based on MEH-PPV conjugated polymers. The polymer-based photodetectors have the advantages of easy processing, low weight, and low cost, and thus are promising candidates for future generations of photodetectors. At present, the quantum efficiency of polymer photodetectors is still low and not comparable to inorganic photodetectors. Therefore, in this thesis we explore ways to enhance the quantum efficiency of polymer photodetectors by using different electron donors, configurations, and implementation of the diffraction optical grating into photodetector structure. We designed, fabricated, and characterized several original types of devices: …

Dna-Templated Assembly Of Metallic Nanowires, Qun Gu

Doctoral Dissertations

Nanowires are widely recognized as key elements in the development of futuristic nanoscale devices of nanoelectronics, optoelectronics and nano-electro-mechanic systems. Lithographic fabrication, however, faces increasing difficulties in the realization of continuously miniaturized features. The “Bottom-up” approach is a promising successor to lithography for fabrication of nanostructures. DNA is a natural template for nanowire assembly. The linear polynucleotide chain has a width of 2 nm and a length of 0.34 run per nucleoside subunit.

One-dimensional magnetic Co and Ni nanoparticles have been assembled in-situ for the first time by use of single DNA molecules as templates. Target metallic nanowires that are …

Biosensing With Microcantilever-Based Sensors, Xiaodong Yan

Doctoral Dissertations

Microcantilevers provide an ideal platform for biosensors. The micron-sized transducer brings several advantages, such as high sensitivity, small sample quantity for analysis, portability, implantable sensor devices, and the ability to be mass produced and integrated into standard microelectronic processing technologies like complementary metal oxide seminconductors (CMOS).

The objective of this research is to investigate and develop modification methods of microcanitlevers for biosensing applications.

Two microcantilever modification methods were investigated. They are self-assembly monolayer method and layer-by-layer method. A fundamental procedure for modification of microcantilevers using the layer-by-layer approach was developed for the first time in this research. These modification methods …

Intelligent Control Of Nonlinear Systems With Actuator Saturation Using Neural Networks, Wenzhi Gao

Doctoral Dissertations

Common actuator nonlinearities such as saturation, deadzone, backlash, and hysteresis are unavoidable in practical industrial control systems, such as computer numerical control (CNC) machines, xy-positioning tables, robot manipulators, overhead crane mechanisms, and more. When the actuator nonlinearities exist in control systems, they may exhibit relatively large steady-state tracking error or even oscillations, cause the closed-loop system instability, and degrade the overall system performance. Proportional-derivative (PD) controller has observed limit cycles if the actuator nonlinearity is not compensated well. The problems are particularly exacerbated when the required accuracy is high, as in micropositioning devices. Due to the non-analytic nature of the …

Cad Model Extraction Of Pcb Signal Discontinuity Using A Circuit Extraction Approach Based On Mixed-Potential Integral Equation Formulation, Shaofeng Luan

Doctoral Dissertations

"In high-speed digital design, signal via transitions on printed circuit boards (PCBs) are becoming an important signal integrity issue. Efficient and accurate models for via transitions are necessary to analyze high bit-rate digital circuit system. The circuit extraction approach based on a mixed-potential integral equation formulation (CEMPIE) is an extension of the Partial Element Equivalent Circuit approach (PEEC) to general multi-layered media. CEMPIE was further developed to include the horizontal current components on the vertical surface and extended to model the discontinuities on multilayer PCBs. A procedure of building SPICE models for signal via transitions between printed circuit board layers …

Polymer-Based Wide-Angle Micro -Optic Lens System With Dynamically Variable Focal Length And Field Of View, Mangilal Agarwal

Doctoral Dissertations

A novel polymer-based integrated wide-angle dynamic micro-optical lens system that can provide variable focal length and field of view (FOV) with large numerical aperture is designed, fabricated, and tested for its optical characteristics.

Initial experiments were conducted using static glass lenses to test for configuration of lenses that could provide wide FOV. From these initial experiments, it was found that the higher FOV could be achieved with double concave (DCV) lenses compared to double convex (DCX) lenses of the same focal length. Further, it was observed that increasing the number of DCV lenses increases FOV. Thus, an integrated dynamic polymer …

Layer-By-Layer Nanoassembly Combined With Microfabrication Techniques For Microelectronics And Microelectromechanical Systems, Jingshi Shi

Doctoral Dissertations

The objective of this work is to investigate the combination of layer-by-layer self-assembly with microfabrication technology and its applications in microelectronics and MEMS.

One can assemble, on a standard silicon wafer, needed multilayers containing different nanoparticles and polymers and then apply various micromanufacturing techniques to form microdevices with nanostructured elements.

Alternate layer-by-layer self-assembly of linear polyions and colloidal silica at elevated temperatures have been firstly studied by QCM and SEM. LbL self-assembly and photolithography were combined to fabricate an indium resistor. The RTA method was employed in the fabrication. Hot-embossing technique as a reasonably fast and moderately expensive technique was …

Fabrication, Characterization, And Modeling Of Organic Capacitors, Schottky Diodes, And Field Effect Transistors, Mo Zhu

Doctoral Dissertations

The objectives of this project are to fabricate, characterize, and model organic microelectronic devices by traditional lithography techniques and Technology Computer Aided Design (TCAD).

Organic microelectronics is becoming a promising field due to its number of advantages in low-cost fabrication for large area substrates. There have been growing studies in organic electronics and optoelectronics. In this project, several organic microelectronic devices are studied with the aid of experimentation and numerical modeling.

Organic metal-insulator-metal (MIM) and metal-insulator-semiconductor (MIS) capacitors consisting of insulating polymer poly(4-vinylphenol) (PVP) have been fabricated by spin-coating, photo lithography, and reactive ion etching techniques. Based on the fabricated …

Polymer-Based Capacitors, Junction Field -Effect Transistors, And A Follower Circuit By Lithography, Self -Assembly, And Ink -Jet Printing Techniques, Yuxin Liu

Doctoral Dissertations

The study of organic materials to create field-effect transistors has recently emerged and is gaining much interest. All-polymer electronic devices are currently in their infancy, like semiconductor devices when they first appeared. As a result, current performance of these devices is in no way comparable to the state-of-the-art semiconductor devices. However, all-polymer devices have a few possible appealing advantages. First, all polymer devices have the potential for low-cost fabrication due to their ease of manufacturability, with fewer and simpler processing steps compared with solid-state semiconductor devices. Secondly, polymer devices offer the ability of material flexibility. Lastly, polymer devices may prove …

Understanding Wavelet Analysis And Filters For Engineering Applications, Chethan Bangalore Parameswariah

Doctoral Dissertations

Wavelets are signal-processing tools that have been of interest due to their characteristics and properties. Clear understanding of wavelets and their properties are a key to successful applications. Many theoretical and application-oriented papers have been written. Yet the choice of a right wavelet for a given application is an ongoing quest that has not been satisfactorily answered. This research has successfully identified certain issues, and an effort has been made to provide an understanding of wavelets by studying the wavelet filters in terms of their pole-zero and magnitude-phase characteristics. The magnitude characteristics of these filters have flat responses in both …

Pattern Recognition For Electric Power System Protection, Yong Sheng

Doctoral Dissertations

The objective of this research is to demonstrate pattern recognition tools such as decision trees (DTs) and neural networks that will improve and automate the design of relay protection functions in electric power systems. Protection functions that will benefit from the research include relay algorithms for high voltage transformer protection (TP) and for high impedance fault (HIF) detection. A methodology, which uses DTs and wavelet analysis to distinguish transformer internal faults from other conditions that are easily mistaken for internal faults, has been developed. Also, a DT based solution is proposed to discriminate HIFs from normal operations that may confuse …

Bulk Micromachining Of Silicon For Moems Prototype, Sung-Dong Suh

Doctoral Dissertations

In this dissertation, the optical application of silicon micromachining technology was investigated in order to create the three-dimensional microstructures that can be used as the components for the MOEMS prototype. These microstructures were designed and fabricated by utilizing corner compensation techniques and silicon bulk micromachining technologies. The fabricated microstructures are silicon mirror arrays that have a 1250 μm etch depth and through-holes across the OE-MCM substrate that has sixteen-fan-out OCDN on front side and a 1mm thickness.

Guided-wave OCDN on MCMs are designed and fabricated to meet the high-speed clocking requirements of next-generation digital systems through a realization of superior …

Kinetics Of Laser Chemical Vapor Deposition Of Carbon And Refractory Metals, Feng Gao

Doctoral Dissertations

Three-dimensional laser chemical vapor deposition (3D-LCVD) has been used to grow rods of carbon, tungsten, titanium, and hafnium from a variety of hydrocarbons and metal halide-based precursors. A novel computerized 3D-LCVD system was designed and successfully used in the experiments. A focused Nd:Yag laser beam (λ = 1.06 μm) was utilized to locally heat up a substrate to deposition temperature. The rods, which grew along the axis of the laser beam, had a typical diameter of 30–80 μm and a length of about 1 mm. The precursors for carbon deposition were the alkynes: propyne, butyne, pentyne, hexyne, and octyne. Propyne …

Cramer-Rao Bound And Optimal Amplitude Estimator Of Superimposed Sinusoidal Signals With Unknown Frequencies, Shaohui Jia

Doctoral Dissertations

This dissertation addresses optimally estimating the amplitudes of superimposed sinusoidal signals with unknown frequencies. The Cramer-Rao Bound of estimating the amplitudes in white Gaussian noise is given, and the maximum likelihood estimator of the amplitudes in this case is shown to be asymptotically efficient at high signal to noise ratio but finite sample size. Applying the theoretical results to signal resolutions, it is shown that the optimal resolution of multiple signals using a finite sample is given by the maximum likelihood estimator of the amplitudes of signals.

Efficient Algorithms And Implementations For Signal Processing, Changbai Xiao

Doctoral Dissertations

A scheme is presented to regain a finite number of lost samples from a Nyquist-rate-sampled band-limited signal f of finite energy by replenishing new sample values of the same number. The result can also be viewed as the solution to a special non-uniform sampling problem.

A scheme is also presented to recover a band-limited function f of finite energy from its sampling values on real sequences with an accumulation point. The result given here can also be viewed as an approach to the extrapolation problem of determination a band-limited function in terms of its given values on a finite interval. …

Bottom-Up Design Of Artificial Neural Network For Single-Lead Electrocardiogram Beat And Rhythm Classification, Srikanth Thiagarajan

Doctoral Dissertations

Performance improvement in computerized Electrocardiogram (ECG) classification is vital to improve reliability in this life-saving technology. The non-linearly overlapping nature of the ECG classification task prevents the statistical and the syntactic procedures from reaching the maximum performance. A new approach, a neural network-based classification scheme, has been implemented in clinical ECG problems with much success. The focus, however, has been on narrow clinical problem domains and the implementations lacked engineering precision. An optimal utilization of frequency information was missing. This dissertation attempts to improve the accuracy of neural network-based single-lead (lead-II) ECG beat and rhythm classification. A bottom-up approach defined …

Integration Of Battery Energy Storage With Flexible Ac Transmission System Devices, Zhiping Yang

Doctoral Dissertations

"This dissertation, consisting of five papers, presents the results of research on the incorporation of battery energy storage into a Static Synchronous Compensator (StatCom). The main contribution of this body of work is the establishment of the modeling and control of the StatCom/BESS in power system dynamic applications. The first paper is focused on the steady state characteristics of the StatCom and StatCom/BESS. The characteristic curves of output voltage and output power were proposed and used in comparing the functionality of the StatCom and StatCom/BESS. In the second paper, a StatCom model was proposed and used in power flow analysis. …

Cracking In Cycloaliphatic Epoxy/Aluminum Composite Electrical Bushings, Keith Alan Parker

Doctoral Dissertations

The problem of cracking in electrical apparatus bushings as a result of thermal stresses was investigated. The bushings were composed of cycloaliphatic epoxy insulators with embedded aluminum conductors. The problem is due to the difference in coefficients of thermal expansion of the two materials. A solution to the problem had been to coat the conductors before they were formed together with the epoxy insulators. The coating was assumed to prevent cracking by allowing movement between the two materials as their dimensions changed during thermal expansion and contraction. The contribution of the coating was to be established.

The hypothesis was that …

Sonar Three-Dimensional Image Formation For Underwater Vehicular Collision Avoidance, Gary Robert Boucher

Doctoral Dissertations

The last ten years have shown a marked increase in research into Autonomous Underwater Vehicles. A key component of this research is the ability to “look” ahead of the vehicle's projected path and translate active sonar returns into three-dimensional (3-D) computer data structures used to navigate and avoid obstacles. This need to avoid obstacles is also common to other underwater vehicles including submersibles.

Of special interest to this research is the “Occupancy Grid Framework.” This technique divides the forward looking sonar field into cells. These cells can be maintained either in spherical or cartesian coordinate systems.

This research demonstrates a …

The Optimized Electrostatic Motor, Christopher Lee Rambin

Doctoral Dissertations

The most common means of electrically activated actuation is the electromagnetic motor. All electromagnetic motors have a low output to weight ratio and low energy efficiency. The motor's weight is due to the coils and magnets used to generate propulsion. The energy loss is mainly the result of Joule heating that is inherent with any current driven device. An electrostatic motor offers the potential of significantly less weight and higher energy efficiency. This lower weight characteristic is due to the epoxide material used to construct the major components of its propulsion unit. Greater efficiency results from the reduced Joule heating …