Engineering Commons^™

Aging And Sleep Stage Effects On Entropy Of Electroencephalogram Signals, Swetha Vennelaganti

University of Kentucky Master's Theses

The aging brain is characterized by alteration in synaptic contacts, which leads to decline of motor and cognitive functions. These changes are reflected in the age related shifts in power spectrum of electroencephalogram (EEG) signals in both wakefulness and sleep. Various non-linear measures have been used to obtain more insights from EEG analysis compared to the conventional spectral analysis. In our study we used Sample Entropy to quantify regularity of the EEG signal. Because elderly subjects arouse from sleep more often than younger subjects, we hypothesized that Entropy of EEG signals from elderly subjects would be higher than that from …

Role Of Dipoles In The Bulk Phosphor Layer In The Electroluminance Mechanisms Of A.C. Thin Film Electroluminescent Display Devices, Praveen Kumar Sivakumar

University of Kentucky Doctoral Dissertations

The purpose of this dissertation is to advance the understanding of SrS-based a. c. thin film electroluminescent (ACTFEL) devices. The role of traps in the bulk phosphor layer in the light emission mechanism from ACTFEL devices is studied, characterized and modeled.

Experiments were performed to observe the response of the ACTFEL devices to tailored voltage excitations. A physical model was developed to describe the optoelectronic processes taking place in the phosphor; analytical equations were written and numerically simulated to plot the flux and luminance responses of the device to similarly tailored voltage excitations.

The voltage excitation parameters such as amplitude, …

Thevenin Equivalent Circuit Estimation And Application For Power System Monitoring And Protection, Mohammad M. Iftakhar

University of Kentucky Master's Theses

The Estimation of Thevenin Equivalent Parameters is useful for System Monitoring and Protection. We studied a method for estimating the Thevenin equivalent circuits. We then studied two applications including voltage stability and fault location. A study of the concepts of Voltage Stability is done in the initial part of this thesis. A Six Bus Power System Model was simulated using MATLAB SIMULINK®. Subsequently, the Thevenin Parameters were calculated. The results were then used for two purposes, to calculate the Maximum Power that can be delivered and for Fault Location.

Nanostructured Thin Films And Tubes Of Titania For Room Temperature Sensing Of Gases, Satish Kumar Kandala

University of Kentucky Master's Theses

The main objective of this work was to study the applicability of Nano porous/Nanocrystalline TiO₂ films for serving the growing demand for fast accurate and low cost air quality analysis techniques. The sensitivity of response to variations in microstructure pointed the way to obtain controlled, reproducible and regular microstructures with critical dimensions proportionate with the Debye- length of the oxide. This work aimed to study the sensor properties of thin films of Nanocrystalline Titania and Titania nanotubes at room temperature. Nano porous/Nanocrystalline TiO₂ films were fabricated through evaporation driven convection/sol-gel method by controlling the process conditions. We also …

Synthesis And Characterization Of Schottky Diodes On N-Type Cdte Nanowires Embedded In Porous Alumina Templates, Srikanth Yanamanagandla

University of Kentucky Master's Theses

This work focuses on the growth of vertically aligned CdTe nanowire arrays of controllable diameter and length using cathodic electro deposition in anodized alumina templates. This step was followed by annealing at 250° C in a reducing environment (95% Ar + 5% H2). AAO template over ITO-glass was used as starting template for the device fabrication. The deposited nanowires showed nanocrystalline cubic phase structures with a strong preference in [111] direction. First gold (Au) was deposited into AAO using cathodic electro deposition. This was followed by CdTe deposition into the pore. Gold was deposited first as it aids the growth …

Conversion Of One-Way Street Pairs To Two-Way Operations In Downtown Birmingham, Jugnu Chemmannur

All ETDs from UAB

In recent years, higher-than-ever gas prices and soaring living expenses are driv-ing people back to city centers in search of reduced travel costs and greater proximity to services. This calls for an immediate need to revive downtown areas to make them attrac-tive and increase their efficiency at accommodating a variety of transportation modes, motorized and non-motorized. To help support this revival, researchers are conducting studies countrywide to understand the effects and relevance of conversion of one-way streets to two-way opera-tions. This paper reports the findings of a study that investigated the feasibility and poten-tial impacts of street conversion options on …

Ethernet Controller Design For An Embedded System Using Advanced Fpga Technology, Eddie L. Groom

All ETDs from UAB

In this work, an embedded Ethernet controller platform was implemented using reconfigurable hardware technology that incorporates system-level components. The specialized hardware and software work flows necessary to implement an embedded system using highly integrated electronics are not commonly addressed in academic environments. The primary objective of this work was to fill this void by describing and demonstrating the hardware/software co-design processes used to implement the project’s embedded Ethernet controller. Ethernet was selected as the project’s design focus to provide an example of the processes used to integrate common system-level components into an embedded system. To analyze the performance of this …

Ex-Situ And In-Situ Selenization Of Copper-Indium And Copper-Boron Thin Films, Rodney J. Soukup, Natale J. Ianno, Chad Kamler, Martin Diaz, Shuchi Sharma, James Huguenin-Love, Jiri Olejnicek

Department of Electrical and Computer Engineering: Faculty Publications

It has recently been established that the ideal bandgap for terrestrial photovoltaics is 1.37 eV and the bandgap for CulnSe2 is only around 1.04 eV. Thus, a larger bandgap is needed. However, neither the substitution of Ga nor of AI has made a high efficiency solar cell absorber with a band gap of 1.37 eV possible. B, an even smaller atom, should require less atomic substitution than either Ga or AI to achieve a wider bandgap. In order to fabricate a thin film of Culn_xB_1-xSe₂ (CIBS), Cu, In and B were deposited from a variety …

Grid Connection Requirements And Solutions For Dfig Wind Turbines, Wei Qiao, Ronald G. Harley

Department of Electrical and Computer Engineering: Faculty Publications

As the number and size of windfarms continue to grow,many countries have established or are developing a set of specific requirements (i.e., grid codes) for operation and grid connection of windfarms. The objective of these grid codes is to ensure that wind farms do not adversely affect the power system operation with respect to security of supply, reliability and power quality. This paper reviews major grid code requirements for wind farms, and investigates various technologies developed by and solutions proposed by researchers and wind turbine manufactures in order to meet these requirements. In addition, some ofthe authors' work on these …

Reliability-Based Stand-Alone Photovoltaic System Sizing Design- A Case Study, Haifeng Ge, Liqin Ni, Sohrab Asgarpoor

Department of Electrical and Computer Engineering: Faculty Publications

This paper introduces a method for designing a standalone photovoltaic system to improve the load point reliability, extend the operation life, and minimize the design cost. This approach examines the impacts of solar panel sizes, tilt angles and battery volumes toward load point reliability, as well as the expected system life, by using real insolation data in a given location and random load burdens. The reliability evaluation incorporating solar insolation variations and load point uncertainty is performed. Life evaluation of battery is included in this paper with consideration of the battery State of Charge (SoC) history. The Economical analysis to …

A Quantitative Study Of Mobility Impact For Real- Time Services On A Wi-Fi Multi-Hop Network, Ting Zhou, Hamid Sharif, Michael Hempel, Puttipong Mahasukhon, Wei Wang, Song Ci

Department of Electrical and Computer Engineering: Faculty Publications

In this paper, we analyze the performance of mobile real time services in a large-scale IEEE 802.11 multi-hop network. We present our field measurements with discussion of performance bottlenecks for VoIP services under mobile scenarios. We utilized our test bed which is located in Nebraska and supported by the University of Nebraska-Lincoln (UNL), US Federal Railroads Administrations (FRA), and major US railroad companies. Our UNL-FRA test bed consists of 8 outdoor access point towers, which are deployed along 3.5 mile of BNSF railroad. Passive measurement approaches are taken to ensure the integrity of collected data and multi-layer stream based packet …

Full-Wave Finite-Difference Time-Domain Simulation Of Electromagnetic Cloaking Structures, Yan Zhao, Christos Argyropoulos, Yang Hao

Department of Electrical and Computer Engineering: Faculty Publications

This paper proposes a radial dependent dispersive finitedifference time-domain method for the modeling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects placed inside the cloak are ‘invisible’ to external electromagnetic fields. However for the simplified cloak based on linear transformations, the back scattering has a similar level to the case of a PEC cylinder without any cloak, rendering the object still being ‘visible’. It is also demonstrated numerically that the simplified cloak based on …

Gene Expression Analysis Of Embryonic Stem Cells Expressing Ve-Cadherin (Cd144) During Endothelial Differentiation, Vesna Nikolova-Krstevski, Manoj Bhasin, Hasan H. Otu, Towia A. Libermann, Peter Oettgen

Department of Electrical and Computer Engineering: Faculty Publications

Background: Endothelial differentiation occurs during normal vascular development in the developing embryo. This process is recapitulated in the adult when endothelial progenitor cells are generated in the bone marrow and can contribute to vascular repair or angiogenesis at sites of vascular injury or ischemia. The molecular mechanisms of endothelial differentiation remain incompletely understood. Novel approaches are needed to identify the factors that regulate endothelial differentiation.

Methods: Mouse embryonic stem (ES) cells were used to further define the molecular mechanisms of endothelial differentiation. By flow cytometry a population of VEGF-R2 positive cells was identified as early as 2.5 days after differentiation …

Aspects Of Producing, Directing, Conditioning, Impinging And Detecting Spectroscopic Electromagnetic Radiation From Small Spots On Samples, Martin M. Liphardt, Ping He, Blaine D. Johs, Galen L. Pfeiffers, James D. Welch, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

Sytems and mehtods for providing and enhancing electromagnetic radiation beam radail energy homogeneity and intensity vs. wavelength content, for reliably directing electromagnetic radiation emitted by a source thereof in a common direction, for achromatically reducing spot size on a sample (eg. liquid cavity containing lenses and low aberration 1:1 imaging systems modified to perform as spatial filters), and for directing directing different wavelengths into different detectors, in ellipsometer, polarizer or the like systems.

System And Method Ofselectively Monitoring Sample Front And Backside Reflections In Ellipsometer And The Like Systems, James D. Welch, John A. Woollam, Martin M Liphardt

Department of Electrical and Computer Engineering: Faculty Publications

A spectrophotometer, reflectometer, ellipsometer polarimeter or the like system having a detector means for independently intercepting electromagnetic radiation reflected from a sample frontside or backside, and methodology for pursuing less correlated determination of refractive index and thickness values.

Non-Optimal Receiver For Space Time Spreading Across A Time Hopping Over Ultra Wideband Ppm, Peter Vial, Beata Wysocki, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

A novel non-optimal chip based technique is proposed to use two antennas to transmit data across a Direct Sequence Time Hopping Ultra Wideband dual antenna wireless communication system to a single receiver. The spread data is sent over the independent channels using the Space Time Spreading technique to encode the chips which are sent on each antenna simultaneously. A hard decision is made at each chip of the spreading code received based on the known Channel State Information which Pulse Position Modulated signal was received from each antenna. The paper shows that by adapting the Space Time Spreading technique to …

Performance Analysis Of Multi-Hop Ieee 802.11 Dcf Backhaul Networks, Puttipong Mahasukhon, Hamid Sharif, Michael Hempel, Ting Zhou, Wei Wang, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Because of the wide deployment of 802.11 equipments in the past decade, current applications are not limited anymore to only single Access Points (AP) deployments for indoor usage, but have been extended to multi-hop networks to fulfill the need of high speed connectivity in mobile environments, where the analysis of multi-hop networks is extremely complicated. The behavior of an AP is dependent not only on its neighbors’ behavior, but also on the behavior of other hidden nodes. In this paper, we provide an accurate and verified multi-hop wireless backhaul analysis for performance of IEEE 802.11 DCF in terms of the …

Cooperative Communication In Space-Time-Frequency Coded Mb-Ofdm Uwb, L. C. Tran, A. Mertins, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Though cooperative communication has been intensively examined for general wireless systems, such as mobile and ad-hoc networks, it has been almost unexplored in the case of Space-Time-Frequency Coded Multi-band OFDM Ultra-Wideband (STFC MB-OFDM UWB). This paper proposes a framework of cooperative communication in such systems where nodes are equipped with only one antenna. Simulation results show that cooperative communication might, in some cases, provide better error performance than non-cooperative communication without any additional transmission power.

Rippling Of Polymer Nanofibers, Xiang-Fa Wu, Yulia Kostogorova-Beller, Alexander Goponenko, Haoqing Hou, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

This paper studies the evolution mechanism of surface rippling in polymer nanofibers under axial stretching. This rippling phenomenon has been detected in as-electrospun polyacrylonitrile in recent single-fiber tension tests, and in electrospun polyimide nanofibers after imidization. We herein propose a one-dimensional nonlinear elastic model that takes into account the combined effect of surface tension and nonlinear elasticity during the rippling initiation and its evolution in compliant polymer nanofibers. The polymer nanofiber is modeled as an incompressible, isotropically hyperelastic Mooney-Rivlin solid. The fiber geometry prior to rippling is considered as a long circular cylinder. The governing equation of surface rippling is …

Analysis Of The Effects Of The Residual Charge And Gap Size On Electrospun Nanofiber Alignment In A Gap Method, Lihua Liu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

In this paper, the effects of residual charges on nanofiber alignment in a gap method are studied and presented. The gap method was presented by Li and Xia (2003 Nano Lett. 3 1167); in it, a gap is introduced into a traditional collector. Due to the non-perfect conductivity of electrospun nanofibers, they carry residual charges after deposition across the gap. These residual charges will interact with the charges carried by the upcoming jet/fiber, that will also deposit across the gap. The effects of these charge interactions on nanofiber alignment were studied numerically at various gap sizes. Results showed that alignments …

Simultaneous Birefringence, Small- And Wide-Angle X-Ray Scattering To Detect Precursors And Characterize Morphology Development During Flow-Induced Crystallization Of Polymers, Lucia Fernandez-Ballester, Tim Gough, Florian Meneau, Wim Bras, Fernando Ania, Francisco Jose Balta-Calleja, Julia A. Kornfield

Department of Engineering Mechanics: Faculty Publications

An experimental configuration that combines the powerful capabilities of a short-term shearing apparatus with simultaneous optical and X-ray scattering techniques is demonstrated, connecting the earliest events that occur during shear-induced crystallization of a polymer melt with the subsequent kinetics and morphology development. Oriented precursors are at the heart of the great effects that flow can produce on polymer crystallization (strongly enhanced kinetics and formation of highly oriented crystallites), and their creation is highly dependent on material properties and the level of stress applied. The sensitivity of rheo-optics enables the detection of these dilute shear-induced precursors as they form during flow, …

Missouri River Recovery Program Keeping Recovery On Track: Annual Report

United States Army Corps of Engineers, Omaha District

Each calendar year, the U.S. Army Corps of Engineers produces a report to document the progress of the Missouri River Recovery Program (MRRP). The Annual Report describes the team’s success in meeting the requirements laid out in the U.S. Fish and Wildlife Service’s 2000 Biological Opinion, amended in 2003, on the Operation of the Missouri River Main Stem System, Operation and Maintenance of the Missouri River Bank Stabilization and Navigation Project and Operation of the Kansas River Reservoir System.

This fact sheet will highlight MRRP efforts in 2008, including new projects, program successes and areas for improvement.

Missouri River Recovery Program: Emergent Sandbar Habitat Program

United States Army Corps of Engineers, Omaha District

States, cities and individuals benefit greatly from a healthy and thriving Missouri River. Maintaining a healthy river, including protecting species that live along the river, is a top priority for the U.S. Army Corps of Engineers and the U.S. Congress.

The survival of the endangered least tern and threatened piping plover is crucial to maintaining a thriving ecosystem on the Missouri River. While both shorebirds nest elsewhere as well, the sandbars of the Missouri River and reservoir shorelines are important to their overall survival. In 2002, the U.S. Fish and Wildlife Service designated areas along much of the Missouri River …

Missouri River Recovery Program: Using The Best Available Science: Monitoring Program

United States Army Corps of Engineers, Omaha District

There is a growing body of information surrounding the manner in which a healthy
river system, such as the Missouri River, functions naturally. As we work towards mitigation, recovery and ultimately restoration, an extensive science program has been implemented so that our actions can be assessed and adjusted as we move towards meeting Missouri River Recovery Program (MRRP) goals.

Missouri River Recovery Program: Finding The Right Balance: Sediment Management

United States Army Corps of Engineers, Omaha District

The goal of the Missouri River Recovery Program (MRRP) is to create a sustainable ecosystem for the river’s native species while protecting and maintaining the Corps’ congressionally-authorized project purposes. Many of the river’s uses – such as habitat, agriculture, municipal water use, flood protection, navigation and hydropower – can be threatened by imbalanced sediment distribution in sections of the Missouri River and its tributaries.

Missouri River Recovery Program: The Perils Of The Pallid Sturgeon

United States Army Corps of Engineers, Omaha District

The pallid sturgeon is native to the Yellowstone River, Missouri River, middle and lower Mississippi River, and the lower segments of their major tributaries. It is a bottom-dwelling fish that lives in large, turbid, freeflowing rivers. The pallid sturgeon has poor vision and relies on its highly sensitive barbels to locate food. Individuals can live up to 70 years, and females do not reproduce until they are 15 to 20 years old.

Historical records indicate that the pallid sturgeon was never a common species, but it has experienced significant declines in distribution and abundance over the last 75 years. During …

Missouri River Recovery Program: Spring Rise And The Missouri River

United States Army Corps of Engineers, Omaha District

Spring rise is a term used to describe the natural fluctuations in a river’s water level. Flooding is a natural part of a river’s relationship with its surrounding floodplain, and a river’s native wildlife and plant life become specially adapted to a river’s annual rise and fall. The frequency, duration, magnitude and timing of a river’s floods determine the types of species that associate with the river, over time creating an interdependent food web and ecosystem. In addition to controlling river biodiversity, spring rises affect the physical environment by adding nutrients to the surroundings, creating habitats for certain species, and …

U.S. Army Corps Of Engineers Omaha District Quarterly Drought Report, February 2008

United States Army Corps of Engineers, Omaha District

Current Conditions

Reservoir Predictions

Drought Outlook

Missouri River Region Mountain Snowpack Report

Ft. Peck, Montana

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Garrison, North Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Boat Ramp Information

Noxious Weeds Overview

Cultural Resources Overview

Other Areas of Interest/Concern

Oahe, South Dakota

Reservoir Elevation Overview

Water Intake Overview

Access Overview

Noxious Weeds Overview

Cultural Resources Overview

Mainstem Reservoir Storage Comparison Water Years 2004, 2005, 2006, 2007, 2008

Ft. Peck, MT

Garrison, ND

Oahe, SD

Average Min-Sum Decoding Of Ldpc Codes, Nathan Axvig, Deanna Dreher, Katherine Morrison, Eric T. Psota, Lance C. Pérez, Judy L. Walker

Department of Mathematics: Faculty Publications

Simulations have shown that the outputs of minsum (MS) decoding generally behave in one of two ways: the output either eventually stabilizes at a codeword or eventually cycles through a finite set of vectors that may include both codewords and non-codewords. This inconsistency in MS across iterations has significantly contributed to the difficulty in studying the performance of this decoder. To overcome this problem, a new decoder, average min-sum (AMS), is proposed; this decoder outputs the average of the min-sum output vectors over a finite set of iterations. Simulations comparing MS, AMS, linear programming (LP) decoding, and maximum likelihood (ML) …

Numerical Simulation Of A Novel Blast Wave Mitigation Device, Zhenbi Su, Wen Peng, Zhaoyan Zhang, George Gogos, Reed Skaggs, Bryan Cheeseman

Department of Mechanical and Materials Engineering: Faculty Publications

This paper proposes a novel blast wave mitigation device, consisting of a piston–cylinder assembly. A shock wave is induced inside the device when it is subject to a blast wave. The shock wave propagates inside the device and is reflected repeatedly. The physical processes within the blast wave mitigation device are simulated numerically. Numerical predictions are in excellent agreement with analytical solutions for special cases of the investigated problem that are available in the literature. The peak pressure on the base of the device caused by the blast wave is studied using a number of design parameters. The numerical simulation …