Engineering Commons^™

Shared Data Acquisition System For Real-Time Power Systems Applications, Yi-Fang Hsu

Electrical Engineering Theses - Archive

Digital signal processing chip (DSP's) can be used to perform data analysis computation and have very good performance in real-time system. Digital filters can be designed with consideration of both magnitude and phase responses for digital re-sampling in power system applications. The design consists of two parts: magnitude approximation and group delay compensation. It compromises between the amount of calculation needed to implement the filters and the performance of the filters, which makes the filters good candidates for both real-time and offline applications.

Biomechanical Properties Of Anterior Vaginal Wall Tissue In Post-Menopausal Women, Aradhana Bhatt

Bioengineering Theses - Archive

Cystocele repair in post-menopausal women suffering from urinary incontinence and associated vaginal prolapse is a common method of palliation. In this method, there is surgical reduction of vaginal tissue and the weak cross-sections are often supported with a synthetic sling fashioned from polymer mesh material. Some sling-supported and unsupported repairs fail over the years. The reasons for these failures are unclear, due in part to a lack of fundamental knowledge of the mechanisms associated with cystocele and vaginal prolapse. The aim of this study was to understand the mechanisms of tissue failure by biomechanical and ultrastructural studies. We take advantage …

Estimation Of Current From Near-Field Measurement, Haixiao Weng, Daryl G. Beetner, Richard E. Dubroff, Jin Shi

Electrical and Computer Engineering Faculty Research & Creative Works

Knowledge of high-frequency currents in the chip and chip-package are necessary for EMI analysis and prediction, though measurement of these currents may be difficult to obtain in many cases. One possibility is to estimate currents from near-field scan data. In this paper, measurements were made of the magnetic field over a simple circuit and a chip package. The current flowing in the circuit and the chip lead frame was estimated from the compensated near-field data and compared with measurements made directly on the pins. Estimation was performed both with and without structural information of the lead frame. The susceptibility of …

Neural Network Detection And Identification Of Electronic Devices Based On Their Unintended Emissions, Haixiao Weng, Xiaopeng Dong, Xiao Hu, Daryl G. Beetner, Todd H. Hubing, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic emissions were measured from several radio receivers to demonstrate the possibility of detecting and identifying these devices based on their unintended emissions. Radiated fields from the different radio receivers have unique characteristics that can be used to identify these devices by analyzing time-frequency plots of measured radiation. A neural network was also developed for automated device detection.

Validation Of Circuit Extraction Procedure By Means Of Frequency And Time Domain Measurement, Giulio Antonini, Antonio Ciccomancini Scogna, Antonio Orlandi, Vittorio Ricchiuti, Giuseppe Selli, Shaofeng Luan, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Aim of this paper is the validation in both frequency and time domain of the procedure to extract fully H-Spice compatible equivalent circuits of structures on printed circuit boards. The procedure is initiated by standard measurement of scattering parameters between 40MHz to 20GH. After the extraction of the equivalent circuit, the computed scattering parameters are compared with those measured. The same equivalent circuit is also used for transient analysis in order to compare TDR measurement and eye-pattern to a pseudo-random bit sequence with those coming from the simulations.

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 …

Revised Asce Specification For The Design Of Cold-Formed Stainless Steel Structural Members, Shin Hua Lin, Wei Wen Yu, Theodore V. Galambos, Edward Wang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Since the publication of the first edition of the AISI specification for the design of light gage cold-formed stainless steel structural members in 1968 [Specification for the design of light gage cold-formed stainless steel structural members. 1968 ed. American Iron and Steel Institute (AISI); 1968], cold-formed stainless-steel members have been increasingly used in building construction and other structural applications due to their superior corrosion resistance, ease of maintenance, pleasing appearance, and high strength. in 1990, the first ASCE standard, ANSI/ASCE-8-90 [Specification for the design of cold-formed stainless steel structural members (ANSI/ASCE 8-90). American Society of Civil Engineers (ASCE); 1991], was …

Comparison Of Near-Field Millimeter-Wave Probes For Detecting Corrosion Precursor Pitting Under Paint, Mohammad Tayeb Ahmad Ghasr, Sergey Kharkovsky, R. Zoughi, Russell A. Austin

Electrical and Computer Engineering Faculty Research & Creative Works

Aircraft structural components such as wings and fuselages are constantly exposed to harsh environments, which make them susceptible to corrosion initiation and growth. To complicate matters, corrosion is normally hidden under paint and primer and cannot be visually detected until significant corrosion has occurred, causing the paint to blister. Corrosion of this type is usually preceded by the presence of corrosion precursor pitting. Hence, early detection of pitting is a critical issue in the maintenance of an aircraft and its structural components. Near-field microwave nondestructive testing techniques have been successfully used for detection of corrosion under paint, including very small …

Determination Of Microwave Dielectric Properties Of Materials Using A Unique Application Of Embedded Modulated Scatterer Technique, Gabriel S. Freiburger, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The embedded modulated scatterer technique has been investigated in the past as a means of determining the dielectric properties of a material of interest using an open-ended rectangular waveguide and an embedded PIN diode-loaded dipole probe. This technique has been further explored in a unique application utilizing the complex ratio of dynamic reflection coefficients for the two states of the modulated dipole probe. By utilizing this ratio, the calculation of dielectric properties becomes independent of measurement parameters such as distance, orientation, and location of the dipole probe relative to the waveguide radiator. This paper explores this unique application of the …

A Case-Based Technique For Tracking Concept Drift In Spam Filtering, Sarah Jane Delany, Padraig Cunningham, Alexey Tsymbal, Lorcan Coyle

Articles

Spam filtering is a particularly challenging machine learning task as the data distribution and concept being learned changes over time. It exhibits a particularly awkward form of concept drift as the change is driven by spammers wishing to circumvent spam filters. In this paper we show that lazy learning techniques are appropriate for such dynamically changing contexts. We present a case-based system for spam filtering that can learn dynamically. We evaluate its performance as the case-base is updated with new cases. We also explore the benefit of periodically redoing the feature selection process to bring new features into play. Our …

Effect Of Warning Devices On Curve Operating Speeds, Adam Vest, Nikiforos Stamatiadis, Adam Clayton, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study is to evaluate the use of several warning signs and warning methods to identify those that have the greatest impact on reducing vehicle speeds when traversing a horizontal curve. Three sites were selected from a list of proposed sites for the testing of the various warning methods. Each warning treatment was installed and a five-day waiting period was allowed before operating speeds for the treatments were measured. The results of the various warning methods were mixed, however, some warning treatments were able to reduce operating speeds on a consistent basis. The most effective of these …

2005 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green

Kentucky Transportation Center Research Report

The objective of this study was to establish 2005 safety belt and child safety seat usage rates in Kentucky. The 2005 survey continues to document the results after enactment of a statewide mandatory safety belt law in 1994 and safety belt enforcement campaign. Data were collected at 200 randomly selected sites spread across Kentucky. Data from the individual sites were combined into a statewide percentage considering roadway functional classification, geographic region, and vehicle miles traveled. The data show that the usage rate in 2005 (66.7 percent) was slightly higher than that in 2004 (66.0 percent). This compares to 65.5 percent …

Meeting Kentucky’S Transportation Needs And Priorities: Citizens’ Perceptions And Recommendations, Donald L. Hartman, Merl Hackbart, Juita-Elena (Wie) Yusuf, Candice Y. Wallace

Kentucky Transportation Center Research Report

This study was designed to (1) consider the role of public input in the transportation planning process; (2) obtain citizen perceptions of system needs and develop priorities in the state of Kentucky; and (3) use that experience (and the experiences of other states) to provide recommendations for ways to enhance the role of public input in Kentucky’s transportation planning. Telephone survey of Kentucky adults and focus groups of community leaders were utilized to gauge the public’s attitudes and perceptions regarding Kentucky’s transportation needs, issues and priorities, and system satisfaction. The findings from the survey and the focus groups were compared …

Analysis Of Traffic Crash Data In Kentucky (2000 – 2004), Eric R. Green, Kenneth R. Agent, Jerry G. Pigman, Monica L. Barrett

Kentucky Transportation Center Research Report

This report documents an analysis of traffic crash data in Kentucky for the years of 2000 through 2004. A primary objective of this study was to determine average crash statistics for Kentucky highways. Average and critical numbers and rates of crashes were calculated for various types of highways in rural and urban areas. These data can be used in Kentucky’s procedure to identify locations that have abnormal rates or numbers of crashes. The other primary objective of this study was to provide data that can be used in the preparation of the problem identification portion of Kentucky’s Annual Highway Safety …

Basinwide Flood Control: The Waffle, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Energy & Environmental Research Center's proposed system for temporary storage of floodwater in the Red River Basin. Describes the "waffle" concept, and outlines the two project phases. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Polymer Tube Embedded In-Plane Micropump: Design, Analysis And Fabrication, Ashutosh Kole

Mechanical and Aerospace Engineering Theses - Archive

This thesis presents the design, analysis, and fabrication of a novel polymer tube embedded in-plane micropump. The key component of the proposed micropump is a Parylene polymer tube that is embedded into the trench of a silicon die. Advantages of embedding a Parylene polymer tube are biocompatibility and leakage free environments. The issue of leakage of fluid presented in [1] is eliminated by inserting the polymer tube. The tube itself acts as a diaphragm, which transfers the force and motion of thermal actuators to fluid. The structural analysis and the fabrication of the Parylene tube along with the coupled-field multiphysics …

Domain-Wall Magnetoresistance Of Co Nanowires, Renat F. Sabiryanov, Ashok K. Solanki, John D. Burton, Sitaram Jaswal, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

Using density functional theory implemented within a tight-binding linear muffin-tin orbital method we perform calculations of electronic, magnetic, and transport properties of ferromagnetic free-standing fcc Co wires with diameters up to 1.5 nm. We show that finite-size effects play an important role in these nanowires resulting in oscillatory behavior of electronic charge and the magnetization as a function of the wire thickness, and a nonmonotonic behavior of spin-dependent quantized conductance. We calculate the magnetoresistance (MR) of a domain wall (DW) modeled by a spin-spiral region of finite width sandwiched between two semi-infinite Co wire leads. We find that the DW …

Alkali Silica Reaction In Virgin And Recycled Aggregates: State Of The Art And Experimental Investigation Using Astm C 1260 And The Staining Method, Shadi Sami Bajjali

Masters Theses

Alkali silica reaction (ASR) is one of the most prevalent causes of concrete deterioration worldwide. A study done in 1995 showing the impact of ASR on structures stated that 104 concrete dams and spillways, massive concrete structures, have been damaged by alkali silica reaction up to date. Since its discovery by Stanton (1940), there has been significant research on ASR, and major advances have been made in understanding the mechanism underlying ASR-induced expansion and in developing methods of preventing ASR in new and existing concrete through proper measures including proper materials selection and mixture proportioning.

This thesis summarizes the findings …

A Solution: The Waffle, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Energy & Environmental Research Center's proposed system for temporary storage of floodwater in the Red River Basin. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Microwave And Millimeter Wave Imaging Of The Space Shuttle External Fuel Tank Spray On Foam Insulation (Sofi) Using Synthetic Aperture Focusing Techniques (Saft), Joseph Toby Case, J. Robbins, Sergey Kharkovsky, Frank L. Hepburn, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The Space Shuttle Columbia's catastrophic failure is thought to have been caused by a dislodged piece of external tank spray on foam insulation (SOFI) striking the left wing of the orbiter causing significant damage to some of the reinforced carbon/carbon leading edge wing panels. Microwave and millimeter wave nondestructive evaluation methods have shown great potential for inspecting SOFI for the purpose of detecting anomalies such as small air voids that may cause separation of the SOFI from the external tank during a launch. These methods are capable of producing relatively high-resolution images of the interior of SOFI particularly when advanced …

Determination Of High Frequency Package Currents From Near-Field Scan Data, Xiaopeng Dong, Shaowei Deng, Daryl G. Beetner, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Integrated circuits (ICs) are often a significant source of radiated energy from electronic systems. Near-field magnetic scanning is an effective tool for measuring the current distribution in IC packages and investigating chiplevel EMI problems. This paper discusses analysis of near-magnetic field scan data using tangential and normal field measurements. Results show that combining near-field scan results from probes with multiple orientations is an effective way to identify the current paths in IC packages.

Power Integrity Investigation Of Bga Footprints By Means Of The Segmentation Method, Giuseppe Selli, James L. Drewniak, Richard E. Dubroff, Jun Fan, James L. Knighten, Norman W. Smith, Dean Mccoy, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

The engineering of the power delivery network is becoming a fundamental issue in the design of high speed digital systems on PCB's. In fact, providing the required power to the different IC's at the specified noisefree voltage levels allows a correct functioning of the overall PCB systems. More over, the ongoing trend of replacing active devices with peripherally located I/O and PWR/GND pins with areally located I/O and PWR/GND pins (BGA packaged) increases the complexity of the models, when power delivery issues need to be studied in a larger contest, such as the overall PCB's. The employment of the powerful, …

Analysis And Modeling Of A Micro Variable Capacitance Electromechanical Energy Converter, Amita Jindal

Electrical Engineering Theses - Archive

Research and development in microelectromechanical systems (MEMS) have made remarkable progress since 1988. Micro-machines are an integral part of MEMS. However, these machines are not often discussed in most electric machines, power electronics and drive forums due to the relative newness of these machines. This thesis provides an in-depth analysis of a variable capacitance micro-machine (VCM). It gives an insight into the effects of machine geometry, on capacitance and torque profiles of the machine. Tangential and radial components of the electrostatic forces in the air gap of the machine have been investigated to study the effects of mutual flux. These …

Nonlinear Finite Element Model Analysis Of Human Accommodation Lens, Tri Le

Civil Engineering Theses - Archive

The crystalline human lens is modeled by using the finite element software, ABAQUS/CAE Version 6.5-1 as an axisymmetric shell to study the optical power and displacement of anterior and posterior poles induced due to zonule traction. Several different element types were tested to obtain the optimum mesh. These elements were three and six-noded triangular hybrid and four-noded quadrilateral hybrid for modeling of the cortex and nucleus. Constant strain triangular and regular quadrilateral elements were examined for modeling the capsule. One dimensional two degree of freedom spring elements were used to model the anterior, posterior, and equatorial zonules. Five different lens …

Design Of A Reconfigurable State Transition Algorithm For Fuzzy Automata, Paolo A. Tamayo

Masters Theses

An Ontological Controller, a type of supervisory controller used for complex industrial systems, is usually characterized by a large global state set. Monitoring the global state set of these systems is impractical when the desired goal path is chosen since the decision on the next state depends only on a small section of the total state space. The approach is to operate only in a small moving window of the large state transition path. The Hybrid Fuzzy-Boolean Finite State Machine (HFB-FSM) is part of the solution to implement this scheme. The HFB-FSM models the state graph along with plant data …

Improving Time To Market Forecasts: A Comparison Of Two Technology Forecasting Techniques For Predicting U.S. Fighter Jet Introductions From 1944 To 1982, Lane Inman, Timothy R. Anderson, Robert R. Harmon

Engineering and Technology Management Faculty Publications and Presentations

Since its origin in 2001, technology forecasting using data envelopment analysis (TFDEA) has been tested with a number of applications. This paper uses a previously published technology forecast comparison of U.S. fighter jets between the years 1944 and 1982 to compare TFDEA to basic regression. Both techniques use aircraft introduced between 1944 and 1960 to predict the first flights of those fighters introduced between 1960 and 1982. TFDEA was found to better predict the first flight dates than the forecast using regression. These results indicate that TFDEA may be a powerful new technique for predicting complex technological trends and time …

Cathodic Electrodeposition Of Cadmium Oxide, Zinc Oxide And Mixed Cadmium Oxide-Zinc Oxide Thin Films, Ashwin Seshadri

Material Science and Engineering Theses - Archive

Cadmium oxide (CdO) and (CdO)x(ZnO)1-x mixed semiconductor films were cathodically electrodeposited for the first time on F-doped SnO2 substrates. The CdO thin films were deposited from an aqueous 0.1 M KCl medium containing dissolved Cd2+ species and O2. The (CdO)x(ZnO)1-x mixed oxide films were deposited from a bath which contained Zn2+ in addition to the CdO bath constituents. Films were potentiostatically deposited at 80 0C followed by a post-deposition thermal anneal at 450 0C. The mechanism of the electrodeposition was explored using cyclic voltammetry. These samples were then analyzed by X-ray diffraction, scanning electron microscopy, and UV-visible reflectance spectrophotometry. The …

Ndor Regression Equations, Branden J. Strahm, David M. Admiraal

Nebraska Department of Transportation: Research Reports

No abstract provided.

A Framework For Teaching Real–Time Digital Signal Processing With Field–Programmable Gate Arrays, Tyson S. Hall, David V. Anderson

Faculty Works

Many curricula include separate classes in both digital signal processing (DSP) theory and very high-speed integrated circuit hardware description language (VHDL) modeling; however, there are few opportunities given to students to combine these two skills into a working knowledge of DSP hardware design. A pedagogical framework has been developed whereby students can leverage their previous knowledge of DSP theory and VHDL hardware design techniques to design, simulate, synthesize, and test digital signal processing systems. The synthesized hardware is implemented on field-programmable gate arrays (FPGAs), which provide a fast and cost-effective way of prototyping hardware systems in a laboratory environment. This …

Low-Voltage Bandgap Reference Design Utilizing Schottky Diodes, David L. Butler, R. Jacob Baker

Electrical and Computer Engineering Faculty Publications and Presentations

As semiconductor device geometries continue to shrink, the corresponding voltage applied across the processed devices must also be reduced. Therefore reference voltages used in integrated circuits will need to be reduced as well. A typical bandgap reference (BGR) voltage generator uses PN junction diodes or PNP BJT’s to bias the reference. The forward bias voltage of these devices is typically 0.7 volts, and has a limiting effect on how low a reference voltage can be generated, as well as how low a system voltage can be applied. Schottky, or metal-semiconductor (MS), diodes have a lower forward bias voltage, typically of …