Electrical and Electronics Commons^™

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

Analysis Of Fiber Bragg Gratings For Ultrasonic Detection, Tongqing Liu

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Fiber optic sensors became an emerging technique to detect ultrasonic emissions in the last decade. Their light weight, immunity to electromagnetic interference and capacity of being multiplexed make them defeat their electronic counterparts in various applications. In this thesis we presented a novel fiber optic ultrasonic sensor based on pi phase shift fiber Bragg gratings. Numerical simulations were performed to study the characteristics of pi phase shift fiber Bragg gratings impinged by ultrasonic waves. The coupling theory was introduced to analyze the change of fiber Bragg gratings when impinged by ultrasonic waves, and the transfer matrix method was utilized to …

Energy Efficiency Analysis And Optimization On Mobile Video Wireless Delivery, Jianxin Sun

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

Micro-electronic industry has been boosting the capability of wireless mobile devices on full-scale. However, battery, as the only power source of most mobile devices, is experiencing a relatively slow development. Therefore, how to optimally utilize the limited battery energy on mobile devices under a predefined performance requirement becomes a critical issue. On the other hand, it is still unclear that how the battery capacity consumption is allocated on different working pattern of a specific video codec under various tempo-spatial scales and parameters, which has posed a design challenge on power management on multimedia communication system. Furthermore, an optimization method is …

Laser-Induced Multi-Energy Processing In Diamond Growth, Zhiqiang Xie

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Laser-induced multi-energy processing (MEP) introduces resonant vibrational excitations of precursor molecules to conventional chemical vapor deposition methods for material synthesis. In this study, efforts were extended to explore the capability of resonant vibrational excitations for promotion of energy efficiency in chemical reactions, for enhancement of diamond deposition, and for control of chemical reactions. The research project mainly focused on resonant vibrational excitations of precursor molecules using lasers in combustion flame deposition of diamond, which led to: 1) promotion of chemical reactions; 2) enhancement of diamond growth with higher growth rate and better crystallizations; 3) steering of chemical reactions which lead …

Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi

Department of Food Science and Technology: Faculty Publications

Microwave ovens are used extensively for heating a variety of not-ready-to-eat food products. Non-uniform heating of foods in microwave ovens is a major concern in assuring microbiological safety of such products. The non-uniform heating of foods is attributed by complex interaction of microwaves with foods. To understand this complex interaction, a comprehensive model was developed to solve coupled electromagnetic and heat transfer equations using finite-difference time-domain based commercial software. The simulation parameters, cell size, heating time step, and number of iterations for steady state electromagnetic field were optimized. The model was validated by 30 s heating profile of a cylindrical …

Ann Based Load Identification And Forecasting System For The Built Environment, Hosen Hasna

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

"Phantom Loads" cause energy waste in homes and the built environment as a whole. Consumers spend more than $3 billion a year on "Phantom Load" in the United States alone. The goal of this work is to conserve energy by increasing consumer awareness on their energy usage and appropriate tools which in turn will be reducing and /or eliminating phantom loads and mismanagement of the load in the built environment. A further goal is to improve upon existing power distribution systems in the built environment with limited hardware additions to increase energy conservation. This work investigates remote identification of load …

An Rf Cmos Implementation Of An Adaptive Filter For Narrow-Band Interferer Suppression In Uwb Systems, Markus Both

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Ultra-wideband (UWB) technology is a new type of technology for wireless communication that is based on the transmission of low power sub-nanosecond pulses. UWB communication utilizes a large bandwidth that overlaps and is coexistent with other wireless communication standards that can be also considered as narrow-band interferers. Because UWB systems are highly susceptible to narrow-band interferers, there is a demand for interferer suppression. An adaptive filter consisting of a two-element diversity receiver that performs minimum mean square error combining (MMSE) by the LMS algorithm is proposed. Thereby the elements of the LMS algorithm as well as the receiver LNA were …

Highly Efficient Maximum Power Point Tracking Using A Quasi-Double-Boost Dc/Dc Converter For Photovoltaic Systems, Christopher J. Lohmeier

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Solar photovoltaic (PV) panels are a great source of renewable energy generation. The biggest problem with solar systems is relatively low efficiency and high cost. This work hopes to alleviate this problem by using novel power electronic converter and control designs. An electronic DC/DC converter, called “Quasi-Double-Boost DC/DC Converter,” is designed for a Solar PV system. A Maximum Power Point Tracking (MTTP) algorithm is implemented through this converter. This algorithm allows the PV system to work at its highest efficiency. Different current sensing and sensorless technologies used with the converter for the MPPT algorithm are offered and tested. Design aspects …

Nanoparticle Necklace Network Arrays Exhibiting Room Temperature Single-Electron Switching, Jennifer L. Kane

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

A single nanoparticle is one of the most sensitive electronic devices for sensing chemicals in a gas or liquid. The conductivity of a single Au nanoparticle is significantly modulated by the binding of a molecule that alters charge by just one electron. However, the single-electron sensitivity requires cryogenic temperatures and interconnection is not easy. A patterned two-dimensional network of one-dimensional nanoparticle necklaces made up of 10 nm Au particles are fabricated and shown to exhibit similar single-electron effect at room temperature. Furthermore, the long range conductivity of over 10’s of microns makes the structure easy to self-assemble onto conventional microelectronics …

A 2-D Processor Array For Massively Parallel Image Processing, Anantha Krishna Nelliparthi

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The concept of introducing image processing logic within the spatial gaps of an array of photodiodes is the key factor behind the presented work. A two-dimensional massively parallel image processing paradigm based on 8X8 pixel neighborhood digital processors has been designed. A low complexity processor array architecture along with its instruction set has been designed and fully verified on a FPGA platform. Various image processing tests have been run on the FPGA platform to demonstrate the functionality of a design that uses 12 parallel processors. The test results indicate that the architecture is scalable to support high frame rates while …

Low Complexity Feature Extraction For Classification Of Harmonic Signals, Peter William

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this dissertation, feature extraction algorithms have been developed for extraction of characteristic features from harmonic signals. The common theme for all developed algorithms is the simplicity in generating a significant set of features directly from the time domain harmonic signal. The features are a time domain representation of the composite, yet sparse, harmonic signature in the spectral domain.The algorithms are adequate for low-power unattended sensors which perform sensing, feature extraction, and classification in a stand-alone scenario. The first algorithm generates the characteristic features using only the duration between successive zero-crossing intervals. The second algorithm estimates the harmonics’ amplitudes of …

Wireless Embedded Smart Cameras: Performance Analysis And Their Application To Fall Detection For Eldercare., Alvaro Pinto

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Wireless Embedded Smart Camera Networks has received a lot of attention from academia and industry because they are small in size and easy to deploy, and they offer a multitude of attractive applications. They can be used for embedded single unit applications, or can be networked for multi-camera applications.

We first analyze three different operation scenarios for a wireless vision sensor network wherein different levels of local processing is performed. A detailed quantitative comparison of three operation scenarios are presented in terms of energy consumption and latency. This quantitative analysis provides the motivation for performing high-level local processing and decision …

Embedded Radio Frequency Identification Device License Plates For Roadside Use In Nebraska, Dwight L. Mosby Jr.

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

The transportation industry has many stakeholders with different needs that work with advanced technologies. Radio Frequency Identification (RFID) is an emerging technology that is used to track inventory and it holds promise for the transportation industry. This research identifies how to evaluate transportation stakeholder requirements for RFID technologies using a tool described as the House of Quality (HOQ). This research investigates RFID’s ability to work in license plates and may provide infrastructure to support identifying RFID enabled commercial vehicles. This research considers variables that affect the performance of a RFID License Plate System that will use a scanner located at …

Energy Storage And Management For A Small Series Plug-In Hybrid Electric Vehicle, Liqin Ni

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Plug-in hybrid electric vehicles (PHEVs) are gaining increasing interest for both residential and commercial transportation applications. In PHEV design, energy storage system (EES) is a critical component which will impact the overall design efficiency, performance, cost and etc. This dissertation aims to design an advanced energy storage system for a small plug-in hybrid electric vehicle, whose performance will approach very closely to the optimal possible, in terms of energy efficiency and acceleration, for passenger road vehicles application. Moreover, practical automotive requirements are considered during ESS design, such as cost, life time, safety and volume.

This dissertation utilizes ultracapacitors in conjunction …

A Single-Chip Ultra-Wideband Based Wireless Sensor Network Node, Nathan R. Schemm

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

This dissertation presents the design of a next-generation wireless sensor network node. The node incorporates many new and innovative technologies such as an ultra-wideband radio which allows very low-energy communication, a low-power radiation detection front end, and an efficient implementation of dynamic voltage scaling which improves the energy efficiency of the integrated processor. The complete design is integrated on a single chip for maximum power savings and minimal size.

The ultra-wideband transceiver includes many novel techniques to produce a receiver with low power consumption and fast and accurate packet acquisition and reception. These include the use of a standard symmetric …

Robust Image And Video Coding With Adaptive Rate Control, Hongqiang Wang

Department of Computer Electronics and Engineering: Dissertations, Theses, and Student Research

This dissertation is focused on the problem of rate allocation in a resource constrained environment and robustness of video coding over noise channels. A new rate allocation scheme that combines the traditional PCRD-Opt algorithm with the rho domain analysis is proposed for wavelet based image coders. The proposed scheme provides competitive performance as compared with the optimal PCRD-Opt algorithm, while with great reduction on complexity and computational costs. Rate allocation is developed for the Region-Of-Interest (ROI) in the wavelet transform domain for image coding. A recursive region growing method that deter mines the ROI in the transform domain is proposed. …

Propagation Of Ultrashort Laser Pulses Through Water, Jianchao Li, Dennis R. Alexander, Haifeng Zhang, Ufuk Parali, David Doerr, John Clark Bruce Iii, Hao Wang

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, propagation of ultrashort pulses through a long 3.5 meter water channel was studied. Of particular interest was the attenuation of the beam at various lengths along the variable path length and to find an explanation of why the attenuation deviates from typical Beer Lambert law around 3 meters for ultrashort laser pulse transmission. Laser pulses of 10 fs at 75 MHz, 100 fs at 80 MHz and 300 fs at 1 KHz were employed to investigate the effects of pulse duration, spectrum and repetition rate on the attenuation after propagating through water up to 3 meters. Stretched …

Digital Video Display System Using Cathode-Ray Tube, George M. Low, Arthur I. Zygielbaum, Warren L. Martin, Alexander Engel

School of Natural Resources: Faculty Publications

A digital video display system (DWDS) is disclosed for display of image, alphanumeric and other data on a cathode-ray tube (CRT) with sequential raster scan and two, four or eight gray shades. The DVDS includes a central processing unit for ac tivating the system, selecting the X (horizontal axis) and Z (in tensity modulation) modes, and designating the starting loca tion of two successive rasters of data from a memory accessed by a data multiplexer subsystem (DMS). At the end of each raster, the DMS interrupts the computer for a new starting lo cation of a raster of data to …