Digital Commons Network^™

Sustainable Resource Utilization In Manufacturing Of Printed Circuit Board Assembly: Exergy Analysis Of The Process, Subramaniam Saiganesh

University of Kentucky Master's Theses

Engineering for sustainable development requires prudent utilization of resources under economic, environmental and societal constraints. Resource utilization must follow a holistic approach. This brings in a need for comprehensive metrics which are simple, standard and universal. Thermodynamics may offer a metric that focuses on both quality and quantity of energy resources which may carry information to be combined with other metrics. This metric may be a thermodynamic property called exergy or available energy, which provides a better insight into resource use in both energy and non-energy producing systems. This thesis is devoted to a study of the exergy concept in …

Transitional Flow Prediction Of A Compressor Airfoil, Vivek Hariharan

University of Kentucky Master's Theses

The steady flow aerodynamics of a cascade of compressor airfoils is computed using a two-dimensional thin layer Navier-Stokes flow solver. The Dhawan and Narasimha transition model and Mayle‟s transition length model were implemented in this flow solver so that transition from laminar to turbulent flow could be included in the computations. A method to speed up the convergence of the fully turbulent calculations has been introduced. In addition, the effect of turbulence production formulations and including streamline curvature correction in the Spalart-Allmaras turbulence model on the transition calculations is studied. These transitional calculations are correlated with the low and high …

Characterization Of Poly(Methyl Methacrylate Based Nanocomposites Enhanced With Carbon Nanotubes, Andrew Jonathan Placido

University of Kentucky Master's Theses

The viscoelastic relaxation dynamics of a series of poly(methyl methacrylate) [PMMA] based nanocomposites filled with carbon nanotubes have been studied using dynamic mechanical analysis and broadband dielectric spectroscopy. The networks were prepared using four methods: (i) melt mixing, (ii) solution processing, (iii) in-situ polymerization, and (iv) polymer grafting. Nanotube modifications included surface oxidation via acid exposure and surface functionalization for polymer grafting. The effect of variations in processing method and nanotube modification on glass transition temperature (T_g) and relaxation dynamics was investigated. The relaxation behavior of the nanocomposites was sensitive to processing method and nanotube functionalization. Nanotube loading …

Somatic Injury Precedes Distal Atrophy Following Excitotoxic Hippocampal Insult, Lynda Sharrett-Field

University of Kentucky Master's Theses

Excitotoxicity can lead to increases in intracellular Na⁺ and Ca²⁺ concentrations via the glutamatergic NMDA receptors, which can lead to cell death. Detailing the time-dependent degradation of neuronal components in response to excitotoxic challenge may help elucidate the sequence in which these signaling pathways are initiated and further, associate these pathways with topographic cellular demise. Using organotypic hippocampal slice culture technique, tissue from neonatal rat pups was exposed to NMDA, APV, or co-exposed for 24, 72 or 120 hours. Fluorescent microscopy of propidium iodide (PI) was used to evaluate neuronal membrane damage, changes in the density of mature …

Detection Of Roof Boundaries Using Lidar Data And Aerial Photography, Andrew David Gombos

University of Kentucky Master's Theses

The recent growth in inexpensive laser scanning sensors has created entire fields of research aimed at processing this data. One application is determining the polygonal boundaries of roofs, as seen from an overhead view. The resulting building outlines have many commercial as well as military applications. My work in this area has created a segmentation algorithm where the descriptive features are computationally and theoretically simpler than previous methods. A support vector machine is used to segment data points using these features, and their use is not common for roof detection to date. Despite the simplicity of the feature calculations, the …

Numerical Modeling Of The Dynamic Response Of A Multi-Bilinear-Spring Support System, Trey D. Gilliam

University of Kentucky Master's Theses

The Alpha Magnetic Spectrometer is an International Space Station Experiment that features a unique nonlinear support system with no previous flight heritage. The experiment consists of multiple straps with piecewise-linear stiffness curves that support a cryogenic magnet in three-dimensional space inside of a vacuum chamber. The stiffness curves for each strap are essentially bilinear and switch between two distinct slopes at a specified displacement. This highly nonlinear support system poses many questions in regards to feasible computational methods of analysis and possible response behavior. This thesis develops a numerical model for a multi-bilinear-spring support system motivated by the Alpha Magnetic …

Bridge Lessons Learned From The Wenchuan China, Earthquake, W. Phillip Yen, Genda Chen, Mark Yashinski, Youssef M. A. Hashash, Curtis J. Holub, Kehai Wang, Xiaodong Guo

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A strong earthquake of M7.9 occurred in Wenchuan County in Sichuan Province, China, on May 12, 2008. This paper presents the field observations on various types of bridge damages, including unseating of girders, longitudinal and transverse offset of decks, pounding at expansion joints, shear key failure, bearing displacement, column shear, and flexible cracks. Plausible causes of damages and collapses are discussed and the lessons learned from this event are briefly summarized. Some of the postearthquake temporary constructions are also reported.

Crack Detectability And Durability Of Coaxial Cable Sensors In Reinforced Concrete Bridge Applications, Genda Chen, Ryan D. Mcdaniel, Michael A. Brower, David Pommerenke

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The working mechanism and the measurement principle of topology-based crack sensors made of coaxial cables are briefly reviewed. The sensitivity, spatial resolution, and ruggedness of two coaxial cable sensors, respectively made of rubber and Teflon dielectric materials, were compared and validated with laboratory testing of a 4/5-scale, T-shaped, reinforced concrete beam-column specimen. Two Teflon sensors were installed on one of the solid decks of a three-span continuous highway bridge to investigate their durability and measurement repeatability. Laboratory tests indicated that both types of sensors have high sensitivity, but the Teflon sensor has a higher spatial resolution and a negligible spillover …

Interactive Natural User Interfaces, Sean Patrick Janis

Theses

For many years, science fiction entertainment has showcased holographic technology and futuristic user interfaces that have stimulated the world's imagination. Movies such as Star Wars and Minority Report portray characters interacting with free-floating 3D displays and manipulating virtual objects as though they were tangible. While these futuristic concepts are intriguing, it's difficult to locate a commercial, interactive holographic video solution in an everyday electronics store. As used in this work, it should be noted that the term holography refers to artificially created, free-floating objects whereas the traditional term refers to the recording and reconstruction of 3D image data from 2D …

Mahalanobis Taguchi System (Mts) As A Prognostics Tool For Rolling Element Bearing Failures, Ahmet Soylemezoglu, Sarangapani Jagannathan, Can Saygin

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a novel Mahalanobis-Taguchi system (MTS)-Based fault detection, isolation, and prognostics scheme is presented. the proposed data-driven scheme utilizes the Mahalanobis distance (MD)-Based fault clustering and the progression of MD values over time. MD thresholds derived from the clustering analysis are used for fault detection and isolation. When a fault is detected, the prognostics scheme, which monitors the progression of the MD values, is initiated. Then, using a linear approximation, time to failure is estimated. the performance of the scheme has been validated via experiments performed on rolling element bearings inside the spindle headstock of a microcomputer numerical …

A Variable Step-Size Normalized Sign Algorithm For Acoustic Echo Cancelation, Tiange Shao, Yahong Rosa Zheng, Jacob Benesty

Electrical and Computer Engineering Faculty Research & Creative Works

A variable step size normalized sign algorithm (VSS-NSA) is proposed, for acoustic echo cancelation, which adjusts its step size automatically by matching the L1 norm of the a posteriori error to that of the background noise plus near-end signal. Simulation results show that the new algorithm combined with double-talk detection outperforms the dual sign algorithm (DSA) and the normalized triple-state sign algorithm (NTSSA) in terms of convergence rate and stability. ©2010 IEEE.

Route Change Decision Making By Hurricane Evacuees Facing Congestion, R. Michael Robinson, Asad Khattak

VMASC Publications

Successful evacuations of metropolitan areas require overcoming unexpected congestion that reduces traffic flows. Congestion may result from accidents, incidents, or other events that reduce road capacity. Traffic professionals and emergency managers may promote deviations from planned routes to bypass an area of congestion and speed mass exit. However, some route changes may actually reduce traffic flow rates, and in these cases decision makers may want to discourage use of alternate routes. By using results of a behavioral survey of potential hurricane evacuees, this study identifies variables associated with the decision to alter routes and also identifies frequently used information sources. …

Decentralized Nearly Optimal Control Of A Class Of Interconnected Nonlinear Discrete-Time Systems By Using Online Hamilton-Bellman-Jacobi Formulation, S. Mehraeen, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the direct neural dynamic programming technique is utilized to solve the Hamilton Jacobi-Bellman (HJB) equation online and forward-in-time for the decentralized nearly optimal control of nonlinear interconnected discrete-time systems in affine form with unknown internal subsystem and interconnection dynamics. Only the state vector of the local subsystem is considered measurable. the decentralized optimal controller design for each subsystem consists of an action neural network (NN) that is aimed to provide a nearly optimal control signal, and a critic NN which approximates the cost function. the NN weights are tuned online for both the NNs. It is shown …

Hardware Implementation Of Triply Selective Rayleigh Fading Channel Simulators, Fei Ren, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we implement a real-time hardware triply selective Rayleigh fading simulator. This simulator incorporates the inter-tap and spatial correlation matrices into multiple uncorrelated frequency-flat Rayleigh fading waveforms (including temporal correlation) to simulate a multiple-input multiple-output (MIMO) triply selective Rayleigh fading channel. in the correlation incorporation procedure, this simulator uses a Kronecker product method to save a large amount of hardware memories. Occupying 34% hardware resources of one Stratix III FPGA chip, this simulator can simulate 4 x 4 MIMO fading channels with 10 correlated delay-taps per subchannel in real-time for a symbol rate of 3.69 μs. Accuracy of …

Optimal Control Of Affine Nonlinear Continuous-Time Systems, T. Dierks, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the optimal regulation and tracking control of affine nonlinear continuous-time systems with known dynamics is undertaken using a novel single online approximator (SOL)-Based scheme. the SOLA-Based adaptive approach is designed to learn the infinite horizon continuous time Hamilton-Jacobi-Bellman (HJB) equation and its corresponding optimal control input. a novel parameter tuning algorithm is derived which not only ensures the optimal cost (HJB) function and control input are achieved, but also ensures the system states remain bounded during the online learning process. Lyapunov techniques show that all signals are uniformly ultimately bounded (UUB) and the approximated control signal approaches …

A Novel Emulator For Discrete-Time Mimo Triply Selective Fading Channels, Fei Ren, Yahong Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

Hardware implementation of discrete-time triply selective Rayleigh fading channel emulators is proposed for multiple-input multiple-output (MIMO) communications. the proposed work differs from existing ones in that it incorporates temporal correlation, intertap correlation, and spatial correlation matrices into multiple uncorrelated frequency-flat fading waveforms to obtain a triply selective fading channel. the flat fading waveforms with temporal correlation or Doppler spectrum are generated using a sum-of-sinusoid method. the intertap correlation matrix associated with multipath delay spread is computed according to the channel power delay profile and transmit/receive filters. the spatial correlation matrices are predefined inputs associated with transmit and receive antenna arrangements. …

Design And Analysis Of An Fpga-Based, Multi-Processor Hw-Sw System For Scc Applications, Andrew Fitzgerald

Theses

The last 30 years have seen an increase in the complexity of embedded systems from a collection of simple circuits to systems consisting of multiple processors managing a wide variety of devices. This ever increasing complexity frequently requires that high assurance, fail-safe and secure design techniques be applied to protect against possible failures and breaches. To facilitate the implementation of these embedded systems in an efficient way, the FPGA industry recently created new families of devices. New features added to these devices include anti-tamper monitoring, bit stream encryption, and optimized routing architectures for physical and functional logic partition isolation. These …

Improve Stability Operations In Kosovo's Electrical Energy Distribution Network: A Case Study Of Northern Prishtina : [Presentation Given May 18, 2010], Lutfije Dervishi

Theses

Not provided.

Applying Energy Efficiency Standards In Kosovo's Residential Buildings : {Presentation Given November 2010], Lirie Berisha

Theses

This Capstone Project addresses the important problem of low energy efficiency in residential buildings in Kosovo. The building sector is one of the biggest energy users and therefore a cause for being a CO₂ emitter. According to the Kosovo Statistical Office of the Ministry of Public Administration, the total number of households in Kosovo is 370,000, of which 10% or approximately 36,400 are apartments. This percentage of the housing stock consists of privatized apartments from the formerly public rental housing and new apartments’ buildings block, and the other 90 % is individual housing. Based on the information of PHE of …

A Study Of Recent Classification Algorithms And A Novel Approach For Biosignal Data Classification, Eyup Cinar

Theses

Analyzing and understanding human biosignals have been important research areas that have many practical applications in everyday life. For example, Brain Computer Interface is a research area that studies the connection between the human brain and external systems by processing and learning the brain signals called Electroencephalography (EEG) signals. Similarly, various assistive robotics applications are being developed to interpret eye or muscle signals in humans in order to provide control inputs for external devices. The efficiency for all of these applications depends heavily on being able to process and classify human biosignals. Therefore many techniques from Signal Processing and Machine …

Developing Germanium On Nothing (Gon) Nanowire Arrays, Paul Thomas

Theses

Advanced crystal growth techniques enable novel devices and circuit designs to further scale and integrate heterogeneous structures for CMOS, MEMS/NEMS, and optoelectronic applications. In particular, nanowires (NW) are among the promising structures derived from these developments. Research has demonstrated the utility of NWs as a channel material for gate-all-around transistors, high sensitivity biological/chemical sensors, photodetectors, as well as a whole spectrum of LEDs and lasers. However, NW based devices are not without their fabrication challenges. Relatively simple structures for CMOS or MEMS/NEMS processes are difficult to reproduce when many NW based devices rely on a dropcast process. This thesis demonstrates …

Pond Ide: Machine Level Program Development Environment And Register Transfer Level Simulator For A Massively Parallel Computer Architecture, Jesse Muszynski

Theses

As computing architectures are being implemented in late and post silicon technologies, fault tolerance and concurrent operation are becoming increasingly important. It is already common knowledge that manufacturers are putting two, four or even more cores on a single silicon die to improve computing performance. The proposed architecture far exceeds this number by grouping thousands or even millions of simple reduced instruction set computing (RISC) processors, each of which is capable of a single operation at a time, and to communicate with its eight nearest neighbors. In this architecture, if a single core or cluster of cores have defects at …

Characterization Of The Effects Of The Human Head On Communication With Implanted Antennas, Michael A. Pecoraro

Theses

Cranially implanted sensors and electrodes have been used in practice for several years; their applications range from the recording of neural signals for use in Brain-Computer Interfaces to help the disabled, to the treatment of diseases and conditions ranging from Parkinson's disease, multiple sclerosis, depression, etc. Current communication methods with implants, however, are lacking; they run the gamut from physical, percutaneous connections that increase the risk of infection, to wireless links that are slow and uncomfortable for patients. The present work focuses on the characterization of the effects of the human head on communication with cranially implanted antennas for its …

Change Orders And Lessons Learned, Paul Goodrum, Timothy R. B. Taylor, William Lester, Alex Mccoy, Mohammed M. Uddin, Yongwei Shan

Kentucky Transportation Center Research Report

Many times, change is necessary for the success of a project. “Change, defined as any event that results in a modification of the original scope, execution time, or cost of work, happens on most projects due to the uniqueness of each project and the limited resources of time and money available for planning” (Hanna, Camlic, Peterson,& Nordheim, 2002). While change orders are necessary to address unforeseen conditions and other unavoidable or unanticipated occurrences, they tend to negatively affect construction. In most public works, change orders are the main reason for construction delays and cost overruns (Wu, Hsieh, & Cheng, 2005). …

Qualitative Versus Quantitative Data Tools For Sustainable Package Design At Eastman Kodak Company, Elizaveta Liubkina-Yudovich

Theses

Due to the increased sustainability trends in the packaging industry during the last decade and a push from major retailers, in conjunction with the dire economic climate and internal reorganizations within the company, a need for an official design tool was born; a tool that would simplify, unify and improve the design process within the company. Following the creation of the original tool, the Packaging Development and Optimization Tool (PDOT), a critique arose that suggested an addition of LCA data, creating a more quantitatively based tool. A modified design process followed, the Sustainable Packaging Design Tool (SPDT), which utilized LCA …

High Field Induced Stress Suppression Of Gidl Effects In Tfts, Andrew Mccabe

Theses

Gate-Induced drain leakage (GIDL) is an unwanted short-channel effect that occurs at higher drain biases in an overdriven off state of a transistor. The GIDL is the result of a deep depletion region that forms in the drain at high drain-to-gate biases. The depletion region causes significant band bending which in-turn allows conductive band-to-band tunneling creating excess current. In a PFET, electrons tunnel from the drain to the body while holes tunnel into the drain. By utilizing the effects of high energy, or "hot", electrons, the GIDL current in an accumulation-mode PFET can be suppressed. This suppression is thought to …

Maximizing Societal Benefits Associated With Alternative Fuel Subsidies: The Case Of Plug-In Hybrid Electric Vehicles, Samir Nazir

Theses

Government seeks to improve the welfare of its citizenry and intervenes in marketplaces to maximize benefits when externalities are not captured. By analyzing how welfare changes from area to area across the country in response to the same intervention informs where government should act. This thesis analyzes the case of plug-in hybrid electric vehicles (PHEVs). PHEVs have many societal benefits, including improving national security, economic, environmental, and health advantages. The magnitude and distribution of these benefits depends on where PHEVs are deployed. This thesis develops and applies a methodology to determine if the benefits from PHEV deployment vary across the …

Evaluation Of Rumble Stripes, Kenneth R. Agent

Kentucky Transportation Center Research Report

Lane departure has been shown to be a major cause of serious traffic crashes. Installing a rumble strip on the shoulders of two lane roads provide drivers with an audible warning that they are leaving their lane of travel. Painting the edge line on the rumble strip has the possible benefit of providing more wet, nighttime delineation through the portion of the edge line painted on the sloped portion of the groove. The objectives of this study were to: a) monitor the initial installations of rumble stripes and b) evaluate the results of rumble stripe installations.

Ten rural, two-lane road …

The Effects Of Gaas Substrate Miscut On Inas Quantum Dot Optoelectronic Properties: Examined By Photoreflectance (Pr) And Deep Level Transient Spectroscopy (Dlts), Joanne Okvath

Theses

In this work, advanced III-V quantum dot (QD) materials are discussed and examined theoretically. The significance of substrate miscut with regards to QD growth is discussed and previous experimental data are examined to show established trends with regards to favorable miscut degree. In order to examine the miscut effect further, multiple testing techniques are presented which characterize material quality as it pertains to optoelectronic device performance, including optical and electrical spectroscopic methods. The optical probing techniques of photoluminescence (PL) and photoreflectance (PR) are used to experimentally characterize the optical properties of GaAs baseline and InAs/GaAs one-layer QD samples. Experimental results …

Free-Carrier Effects In Polycrystalline Silicon-On-Insulator Photonic Devices, Oshoriamhe Ogah

Theses

Photonic systems integrated into microelectronic systems using the well established integrated chips fabrication technologies offer immense opportunity in overcoming the bandwidth and power limitations IC faces. The use of deposited polycrystalline silicon in the fabrication of photonic devices has the potential of offering monolithic integration, promising electrical and optical properties, under optimized micro-fabrication, and lower costs. In this thesis, the design, fabrication and optical testing of waveguide devices on polycrystalline silicon platform is presented. Single mode polysilicon waveguide devices were fabricated at the RIT SMFL. The polysilicon waveguides fabricated successfully coupled and guided light. The transmission was measured over several …