Digital Commons Network^™

A Hybrid Approach To Decrease Port Influence In Transmission Line Characterization, Jianmin Zhang, David Pommerenke, James L. Drewniak, Richard E. Dubroff, Zhiping Yang, Wheling Cheng, John Fisher, Sergio Camerlo

Electrical and Computer Engineering Faculty Research & Creative Works

Characterization and models for multi-gigabit signaling is an important issue in modern digital system. A good physical based model relies on a precise characterization of the test board. Typically, the characterization of the test board is associated with scattering matrix parameter measurement, which can be done with a VNA (Vector Network Analyzer) in the frequency-domain or a TDR (Time Domain Reflectometer) in the time-domain. The commonly used launch techniques on PCBs (Printed Circuit Boards) associated with the VNA or TDR measurement in the microwave frequency range use SMA or 3.5 mm connectors, in edge-launch or vertical-launch fashions. The transition between …

Effects Of Mutual Coupling On Interference Mitigation With A Focal Plane Array, Michael A. Jensen, Karl F. Warnick

Faculty Publications

A focal plane array feed of electrically small elements has been proposed as a means for achieving high sensitivity for radio astronomy applications in the presence of radio frequency interference (RFI). For a broadband system, mutual coupling effects become significant as the array element spacing becomes small relative to the electromagnetic wavelength. We present a theoretical framework for modeling the effects of mutual coupling and for determining the optimal multiport matching network between array elements and front-end transistor low-noise amplifiers for maximum signal-to-noise ratio (SNR). Numerical results are given for a model scenario including spillover and amplifier thermal noise and …

Toward A More Robust And Accurate Cem Fast Integral Equation Solver For Ic Applications, Weng Cho Chew, Li (Lijun) Jun Jiang, Yun Hui Chu, Gong Li Wang, I. Ting Chiang, Yuancheng Christopher Pan, Jun Sheng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

We review recent advances in fast algorithms for fast integral equation solvers that are useful for IC applications. We review fast solvers for Laplace's equation, which is about 10 times faster than the conventional fast multipole method. Then we review the physics of low-frequency electromagnetics, and the relevant low-frequency method of moments. We describe a fast solver that allows us to solve over one million unknowns on a workstation recently. In addition, we demonstrate the applications of these fast integral equation solvers to the lithography problem. In addition, we propose a scheme whereby we first characterize blocks of linear circuits …

A Three-Dimensional Fdtd Subgridding Method With Separate Spatial And Temporal Subgridding Interfaces, Kai Xiao, David Pommerenke, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

The idea of separating the spatial and temporal subgridding interfaces is introduced in this paper. Based on this idea, the spatial and temporal subgridding algorithms can be developed and analyzed separately. The spatial algorithm was given in the previous paper. In this paper, the temporal subgridding algorithm is described and the stability is illustrated by the analytical formulation of a one-dimensional model. An FDTD code that combines the spatial and temporal subgridding algorithms is implemented. Numerical test models are calculated to show the stability and accuracy of the proposed method.

Developing A Shared Vision: Strategic Planning As A Guide To Technology Funding

ACUTA: Other Publications

In December 2004 ACUTA and WTC sent a survey to 768 ACUTA primary members to determine what issues were important on campuses today and what issues respondents felt will be of importance in the next few years. Questions related to management, strategy, infrastructure, technology, organization, polity, and funding. One of the most interesting observations is that the current and five-year rankings are nearly identical- today's concerns are also your concerns for the future. Here are the highlights of our findings:

A cluster of five management issues were rated very close to the same importance. This cluster included developing a vision …

Investigation Of The Superconducting Properties Of Niobium Radio-Frequency Cavities, Gianluigi Ciovati

Physics Theses & Dissertations

Radio-frequency (rf) superconducting cavities are widely used to increase the energy of a charged particle beam in particle accelerators. The maximum gradients of cavities made of bulk niobium have constantly improved over the last ten years and they are approaching the theoretical limit of the material. Nevertheless, rf tests of niobium cavities are still showing some "anomalous" losses (so-called "Q-drop"), characterized by a marked increase of the surface resistance at high rf fields, in absence of field emission. A low temperature "in-situ" baking under ultra-high vacuum has been successfully applied by several laboratories to reduce those losses and …

The Case For Thoroughly Testing Complex System Dynamic Models, Wayne Wakeland, Megan Hoarfrost

Complex Systems Faculty Publications and Presentations

In order to determine whether model testing is as useful as suggested by modeling experts, the full battery of model tests recommended by Forrester, Senge, Sterman, and others was applied retrospectively to a complex previously-published system dynamics model. The time required to carry out each type of test was captured, and the benefits that resulted from applying each test was determined subjectively. The resulting benefit to cost ratios are reported. These ratios suggest that rather than focusing primarily on sensitivity testing, modelers should consider other types of model tests such as extreme condition tests and family member tests. The study …

Power Transmission Control Using Distributed Max-Flow, Bruce M. Mcmillin, Austin Armbruster, Mariesa Crow, Michael R. Gosnell

Computer Science Faculty Research & Creative Works

Existing maximum flow algorithms use one processor for all calculations or one processor per vertex in a graph to calculate the maximum possible flow through a graph's vertices. This is not suitable for practical implementation. We extend the max-flow work of Goldberg and Tarjan to a distributed algorithm to calculate maximum flow where the number of processors is less than the number of vertices in a graph. Our algorithm is applied to maximizing electrical flow within a power network where the power grid is modeled as a graph. Error detection measures are included to detect problems in a simulated power …

Electromagnetic Wave Propagation Prediction For Wireless Networks Inside Boeing Fuselages, Mennatoallah Youssef

Electrical & Computer Engineering Theses & Dissertations

Commercial grade software is intended for electromagnetic predictions within office buildings; it was used to develop models to analyze propagation inside airplane fuselages. This study shows that Wireless XGTD and Insite software can accurately predict power propagation within airplane fuselages. Current work uses fuselage models, which contain additional internal components. A comparison was made between empty and full fuselage to examine the effects of internal components. Two propagation model types [Fast 3D and Full 3D] were also compared for accuracy to experimental study. It was concluded that completed fuselages are suggested for further simulation study as well as that the …

Mobility-Pattern Based Localization Update Algorithm For Mobile Wireless Sensor Networks, Mohammad Yacoub Al-Laho

Electrical & Computer Engineering Theses & Dissertations

In mobile wireless sensor networks, sensors move in the monitored area at any direction and speed. Unlike many other networking hosts, sensor nodes do not have global addresses. They are often identified by using a location-based addressing scheme. Therefore, it is important to have the knowledge of the sensor location indicating where the data came from. In this thesis, three localization update algorithms were designed, Specifically, a sensor movement is divided into three states: Pause, Linear, and Random. Each state adopts different localization update algorithm. Since complex movement involves different mobility patterns, a state transition model is developed to …

Monte Carlo Simulation Analysis Of Electron Bombardment Of Gallium Nitride For Particle Detector Applications, James Gibson Bolitho

Electrical & Computer Engineering Theses & Dissertations

Gallium Nitride (GaN) is a relatively new and promising semiconductor material. It is finding its place in commercial applications such as transistors, light-emitting diodes, and in blue lasers. The large bandgap of GaN allows for very low canier densities and high breakdown voltages. This combination results in a greatly reduced background current and noise, and can withstand large applied voltages. In addition, GaN is sturdy and has strong mechanical properties. These are all ideal characteristics for application in high-energy particle detection.

In this thesis, the central goal is to assess the response of a GaN-based particle detector through numerical modeling. …

A Multiplier-Less Architecture For High Speed Computation Of Multi-Dimensional Convolution, Ming Zhu Zhang

Electrical & Computer Engineering Theses & Dissertations

One of the most computationally intensive operations in digital image/video processing systems is multi-dimensional convolution. Every image/video processor needs the convolution module in its pre-processing stage. Fast and efficient design of the convolution module in an application specific system is a great challenge in VLSI (Very Large Scale Integration) design. Convolution operator requires a large set of multipliers and accumulators. A high precision multiplier takes enormous amount of VLSI area and it consumes more power. Hence reduction of the number of multipliers is another important challenge in VLSI design. A multiplier-less architecture for the design of a multi-dimensional convolution module …

Correlation Of Fault-Injection To Proton Accelerator Persistent Cross Section Measurements, Keith S. Morgan, Michael J. Wirthlin

Faculty Publications

Sponsorship: Los Alamos National Laboratory. Field Programmable Gate Arrays (FPGAs) are an attractive solution for space system electronics. Unfortunately, FPGAs are susceptible to radiation-induced single-event upsets (SEU). As such, the FPGA Reliability Studies research group (http://reliability.ee.byu.edu) at Brigham Young University has studied ways to effectively measure the static, dynamic and persistent cross sections of an FPGA desgin; each of which are characterized in some way by how the part reacts to an SEU. One such method is to actually radiate an FPGA and monitor how it reacts to SEUs. A cheaper, more efficient solution is to use fault-injection to emulate …

Predicting On-Orbit Seu Rates, Keith S. Morgan, Michael J. Wirthlin

Faculty Publications

As process geometry sizes continue to decrease, microelectronics are becoming more vulnerable to the effects of radiation. Of particular concern are the effects of Single-Event Upsets (SEU) in Field Programmable Gate Arrays (FPGA). An SEU causes a dynamic memory element, such as a flip-flop or latch, to unwantedly change state. Since FPGAs are becoming an increasingly attractive solution for space system electronics, it is desirable to predict static on-orbit SEU rates likely to be encountered by a particular device for any particular orbit. Mean Time Between Failure (MTBF) can directly be calculated from a static SEU rate, allowing a system …

The Hybrid Architecture Parallel Fast Fourier Transform (Hapfft), Joseph M. Palmer

Theses and Dissertations

The FFT is an efficient algorithm for computing the DFT. It drastically reduces the cost of implementing the DFT on digital computing systems. Nevertheless, the FFT is still computationally intensive, and continued technological advances of computers demand larger and faster implementations of this algorithm. Past attempts at producing high-performance, and small FFT implementations, have focused on custom hardware (ASICs and FPGAs). Ultimately, the most efficient have been single-chipped, streaming I/O, pipelined FFT architectures. These architectures increase computational concurrency through the use of hardware pipelining. Streaming I/O, pipelined FFT architectures are capable of accepting a single data sample every clock cycle. …

Electromechanical Analysis Of Piezoelectric Laminated Composite Beams, Ming-Hung Hsu

Journal of Marine Science and Technology–Taiwan

This work demonstrates the electromechanical behavior of piezoelectric laminated composite beams using the differential quadrature method (DQM). The Chebyshev-Gauss-Lobatto sample point equation is used to select the sample points. The electromechanical responses of piezoelectric laminated composite beams with various boundary conditions are determined. The transient responses of the derived systems are calculated using the Wilson-method. In this approach, only nine sample points are required to obtain convergence. Numerical results indicate that the DQM is valid for a piezoelectric laminated composite beam formulation

A Senior Level Polymer Electronics Course: Unique Instruction Or Just Low Cost?, David Braun

Electrical Engineering

After progressing from research laboratories to factories to the market, semiconducting polymers now appear in commercial products and offer educational opportunities. Semiconducting polymers are excellent materials with which to teach semiconductor device fabrication principles, device testing, optical and electronic properties, polymer synthesis, polymer film preparation, and structure-property relationships. Previous publications have emphasized multidisciplinary course modules based on semiconducting polymers.1 This work emphasizes how the use of semiconducting polymers in an undergraduate polymer electronics course benefits electrical engineering and computer engineering students.

System And Method For Differential Data Collection, Jack P. Glas, Vladimir I. Prodanov

Electrical Engineering

The present invention is directed towards a data detector for deriving a data signal from an incoming radio frequency input. The data detector comprises a delay logic which receives an unfiltered signal in quadrature and in-phase components, and applies a delay to each of the in-phase and quadrature phase components of the unfiltered input signal. The detector further comprises a first multiplication logic that multiplies the delayed in-phase component of the unfiltered signal by the quadrature phase component of the unfiltered signal to obtain a first result, and a second multiplication logic that multiplies the delayed quadrature phase component of …

Scene-Based Nonuniformity Correction Technique For Focal-Plane Arrays Using Readout Architecture, Balaji Narayanan, Russell C. Hardie, Robert A. Muse

Electrical and Computer Engineering Faculty Publications

Spatial fixed pattern noise is a common and major problem in modern infrared imagers due to the nonuniform response of the photodiodes in the focal plane array of the imaging system. In addition, the nonuniform response of the readout and the digitization electronics, involved in multiplexing the signals from the photodiodes, causes further nonuniformity. In this paper, we describe a novel scene based nonuniformity correction algorithm that treats the aggregate nonuniformity in separate stages. Firstly, the nonuniformity from the readout amplifiers is corrected using knowledge of the readout architecture of the imaging system. In the second stage, the nonuniformity resulting …

Segmentation Of Thermal Images For Non-Destructive Applications, Solange Yohali

Masters Theses

Infrared Thermogarphy (IR) is used in this project to detect subsurface conditions in concrete specimen for nondestructive testing and evaluations. This thesis goal is to bridge the gap between Infrared Testing and image analysis by developing an algorithm based on the region growing approach to segment the images and identify the voids without human interference or prior knowledge of the conditions. The segmentation algorithm starts with seed points as the hottest pixels in the image, and then regions are grown based on a neighborhood comparison criterion. The algorithm was tested on images collected from concrete specimen containing various man-made defects …

Extending Classical Test To Quantum, Jacob D. Biamonte, Minki Jeong, Jae-Seung Lee, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

We first introduce a method called quantum path verification, where we search for a break in a quantum network. After explaining these capabilities, we address gate internal faults. We present new fault models to represent crosstalk and unwanted nearest neighbor entanglement. When witnessed, these errors are probabilistic, but there is a set of tests that has the highest probability of detecting a fault. We introduce a method of probabilistic set covering to identify this set of tests. A large part of our work consisted of writing a software package that allows us to compare various fault models and test strategies.

Effects Of Piconet Saturation On A Bluetooth Streaming Audio Channel, Theodore L. Josue

Theses and Dissertations

Bluetooth is a technology for wireless personal area networks (WPAN) that eliminates the need for cables, standardizes interfaces, and can automate many standard office processes such as sending and receiving email, synchronizing schedules, or exchanging business cards. With each workstation creating its own Bluetooth network, called a piconet, different Air Force environments have the potential, in some cases, to create more than 50 overlapping piconets, which significantly increases the potential for inter-piconet interference. This research investigates the effects of inter-piconet interference on a Bluetooth channel, streaming audio, offered at 24, 40, and 64 Kbps. It shows that as the number …

Blue-Box Approach To Power Electronics And Machines Educational Laboratories, Robert S. Balog, Zakdy Sorchini, Jonathan W. Kimball, Patrick L. Chapman, Philip T. Krein, Peter W. Sauer

Electrical and Computer Engineering Faculty Research & Creative Works

Our approach to laboratory education in power electronics and electric machines is presented. The approach centers upon "blue-box" laboratory components, that aid the student in rapid experiment assembly without disguising important aspects of the hardware. Several example experiments are presented. Schematics and construction techniques for the hardware are publicly available.

High-Temperature Ferromagnetism In Transition Metal Implanted Wide-Bandgap Semiconductors, Jeremy A. Raley

Theses and Dissertations

Material with both semiconductor and magnetic properties, which is commonly called a dilute magnetic semiconductor (DMS), will prove most useful in the fabrication of spintronic devices. In order to produce a DMS at above room temperature, transition metals (TMs) were implanted into host semiconductors of p-GaN, Al_0.35Ga_0.65N, or ZnO. Magnetic hysteresis measurements using a superconducting quantum interference device (SQUID) magnetometer show that some of the material combinations clearly exhibit ferromagnetism above room temperature. The most promising materials for creating spintronic devices using ion implantation are p-GaN:Mn, Al_0.35Ga_0.65N:Cr, and Fe-implanted ZnO nanotips on …

Wide-Angle Multistatic Synthetic Aperture Radar: Focused Image Formation And Aliasing Artifact Mitigation, Jonathan E. Luminati

Theses and Dissertations

Traditional monostatic Synthetic Aperture Radar (SAR) platforms force the user to choose between two image types: larger, low resolution images or smaller, high resolution images. Switching to a Wide-Angle Multistatic Synthetic Aperture Radar (WAM-SAR) approach allows formation of large high-resolution images. Unfortunately, WAM-SAR suffers from two significant implementation problems. First, wavefront curvature effects, non-linear flight paths, and warped ground planes lead to image defocusing with traditional SAR processing methods. A new 3-D monostatic/bistatic image formation routine solves the defocusing problem, correcting for all relevant wide-angle effects. Inverse SAR (ISAR) imagery from a Radar Cross Section (RCS) chamber validates this approach. …

The Navigation Potential Of Signals Of Opportunity-Based Time Difference Of Arrival Measurements, Kenneth A. Fisher

Theses and Dissertations

This research introduces the concept of navigation potential, NP, to quantify the intrinsic ability to navigate using a given signal. NP theory is a new, information theory-like concept that provides a theoretical performance limit on estimating navigation parameters from a received signal that is modeled through a stochastic mapping of the transmitted signal and measurement noise. NP theory is applied to SOP-based TDOA systems in general as well as for the Gaussian case. Furthermore, the NP is found for a received signal consisting of the transmitted signal, multiple delayed and attenuated replicas of the transmitted signal, and measurement noise. Multipath-based …

A Solution For Eaf Induced Problems In Bulk Power Systems By Fact/Ess, Li Zhang, Yilu Liu, Mark Baldwin, Michael R. Ingram, Dale T. Bradshaw, Steve Eckroad, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Stereo Vision Algorithm Using Propagation Of Correspondences Along An Array Of Cameras, Danyan Ganjali

Theses

One well known problem in stereo vision is the trade-off between precision and accuracy.

In a conventional two camera model, as the baseline separating the two cameras becomes smaller, the images that both cameras produce become more identical. This results in a more accurate set of correspondences, however at the same time causing less precise depth measurement due to the small angle used for triangulation. Similarly, in a larger baseline model, the depth measurement is more precise while the correspondences are not as accurate as of the shorter baseline model. This thesis proposes a method that promises to solve the …

Performance Of Multi-User Codes In Wireless Communications, Muhammad Tauseef Ulislam

Theses

Multi-user codes are a widely used in transmitting user data from base station to mobile station and vice versa. In wireless communications a signal received by a mobile station goes through different fading channels resulting. These multi-paths add constructively and destructively with different delays and attenuation at the mobile station. The autocorrelation and cross correlation properties of the Multi-user codes play a significant role in extracting the user data from the signal corrupted by multipath fading channel.

The thesis presents a comparison of different Multi-user codes based on their autocorrelation and cross correlation properties. These codes are passed through a …

Difference-Expansion Based Reversible Data Hiding And Its Steganalysis, Guangsen Tian

Theses

A novel reversible data embedding method was reported in a recent IEEE journal article. The method was based on difference expansion (DE) technique. It used redundancy in digital images to achieve a high embedding capacity, while keeping visual distortion of the stego-image low. In this thesis, this technique was studied and experimentally evaluated. An effective steganalysis scheme for this DE-based reversible data embedding method was proposed, which used 12-dimensional feature vectors and a Bayes Classifier. The proposed steganalysis scheme steadily achieved a correct classification rate of 99%.