Engineering Commons^™

Crosstalk Analysis By Fast Computational Algorithms, Z. G. Qian, J. Xiong, L. Sun, I. T. Chiang, W. C. Chew, L. (Lijun) J. Jiang, Y. H. Chu

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we will present the use of low frequency fast algorithms for crosstalk analysis. Some criss-cross line structures are studied and time domain signals are demonstrated to ascertain crosstalk effect. ©2005 IEEE.

A Mixed-Form Fast Multipole Algorithm, Li (Lijun) Jun Jiang, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

The fast multipole algorithm manifests in two very different forms at low frequencies and at mid frequencies. Each can operate in their respective regimes, but are not tenable in the other regimes. The paper reports on a way to factorize the Green's function for fast algorithm using a mixed form. The low-frequency fast multipole algorithm (LF-FMA) will be used at low frequencies or the long-wavelength regime, and the multilevel fast multipole algorithm (MLFMA) will be used for the mid frequencies or the shorter-wavelength regime. For object modeling where both long-wavelength and wave physics are important, we propose a mixed-form fast …

The General Variational Formulas For Capacitance Parameter Extraction, W. C. Chew, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

To obtain second order accuracy using the first order data for the capacitance parameter extraction, a set of new generalized variational formulas are presented in this paper. They are complete since they are valid not only for self-capacitances, but also for mutual capacitances. A more general variational formula is derived to account for the asymmetrical elastance matrix case. By these novel formulas the computational accuracy can be significantly improved compared to the conventional direct capacitance extraction method. © 2005 IEEE.

Dynamic Growth Rates Of Microbial Populations In Activated Sludge Systems, Peter George Stroot, Pascal E. Saikaly, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Results of mathematical modeling and whole cell 16S ribosomal RNA-targeted fluorescence in situ hybridizations challenge the widely held perception that microbial populations in "steady-state" activated sludge systems share a common net growth rate that is proportional to the inverse of the mean cell residence time. Our results are significant because they encourage bioprocess engineers to appreciate the differences in growth physiology among individual microbial populations in complex mixed microbial communities such as suspended growth activated sludge bioreactor systems.

Fiscal Year 2005 Fhwa-536 Report For The Kentucky Transportation Cabinet, Steven Douglas Kreis

Kentucky Transportation Center Research Report

The Federal Highway Administration (FHWA) requires state transportation agencies to submit a biennial report on local highway finances. The purpose of these reports is to provide FHWA with the data it needs to capture the financing of highway activities at the local level. Based on this information, it can identify trends in revenue, expenditures, investments, and program development, and in turn make decisions about future investments. The report, FHWA-536, asks agencies to report on four areas of local highway finance: 1) disposition of highway-user revenues; 2) revenues used for roads and streets identified by source and funding type; 3) road …

Capacitated And Uncapacitated Facilities Locationallocation Problem With Sensitive Prices, Stochastic Demands, And Inventory, Yaser Al-Alawi

Dissertations

This study developed a quantitative model that solves a facility locationallocation (LA) problem that maximizes the net profits generated from expected sales. The model was formulated to take into consideration demand uncertainty, sensitive prices, and existence of inventory for capacitated and uncapacitated facilities. Four new models for the LA problem with stochastic demands and inventory were developed and studied. The four models were combinations of capacitated and uncapacitated facilities and sensitive and insensitive prices.

A new method was proposed for achieving optimality, and an approximation procedure was developed that could find near-optimal solutions for problems that could not be solved …

Leveraging Itil To Govern Aoc Information Technology, Robert V. Weaver Iii

Theses and Dissertations

The Air Operations Center (AOC) is a complex system of systems that is resistant to traditional engineering controls and management strategies. The US Air Force (USAF) seeks to transform its antiquated AOC Information Technology (IT) management function into an agile enterprise capable of leveraging cutting-edge technology by aligning the AOC's infrastructure with its organizational strategies and vision. The USAF calls this effort a transformation. Private industry calls it IT Governance. To achieve AOC IT Governance, the USAF must stop managing infrastructure components and start managing IT services. IT Service Management abstracts business processes from the technology supporting them by creating …

Characterization Of Binary Offset Carrier (Boc) Systems Coexisting With Other Wideband Signals, John M. Hedenberg

Theses and Dissertations

Results for modeling, simulation, and analysis of interference effects that modern interfering signals have on the system performance of the Binary Offset Carrier (BOC) signals, such as the Global Positioning System (GPS) Military System (M-Code signal) are addressed in this work. Three signals are addressed as potential interferers. These include the current GPS clear/acquisition code (C/A-Code) signal, the current GPS precision code (P-Code) signal, and an Orthogonal Frequency Division Multiplexed (OFDM) signal. All of these potential interferers are modeled as coexisting within the same bandwidth as the M-Code signal. Interference effects are characterized by comparing the bit error performance of …

Gaussian Mixture Reduction For Bayesian Target Tracking In Clutter, David J. Petrucci

Theses and Dissertations

The Bayesian solution for tracking a target in clutter results naturally in a target state Gaussian mixture probability density function (pdf) which is a sum of weighted Gaussian pdf's, or mixture components. As new tracking measurements are received, the number of mixture components increases without bound, and eventually a reduced-component approximation of the original Gaussian mixture pdf is necessary to evaluate the target state pdf efficiently while maintaining good tracking performance. Many approximation methods exist, but these methods are either ad hoc or use rather crude approximation techniques. Recent studies have shown that a measure-function-based mixture reduction algorithm (MRA) may …

Performance Measurements Of Direct Air Injection In A Cavity-Based Flameholder For A Supersonic Combustor, Scott G. Edens

Theses and Dissertations

For several years the Air Force Research Lab Propulsion Directorate has been studying the difficulties in fueling supersonic combustion ramjet engines with hydrocarbon based fuels. Recent investigations have focused on the use of direct air injection into a directly-fueled cavity-based flameholder. Direct air injection has been shown qualitatively to be a valuable tool for improving cavity combustion. Little quantitative data is available that characterizes the performance of cavity-based flameholders. The objective of this research was to quantitatively determine the specific advantages and disadvantages of the direct air injection scheme. This was accomplished via intrusive probing into a supersonic free stream …

Wind Tunnel Study Of Interference Effects Relating To Aft Supersonic Ejection Of A Store, Timothy P. Jung

Theses and Dissertations

An investigation into the issues surrounding the release of a store into a supersonic wake was conducted. A 10-degree half-angle cone was used to model the carrier vehicle as well as the store. The store was 42% than the vehicle. The experiments were conducted at a freestream Mach number of 2.93 and at zero degrees angle of attack. This study analyzed the effects of a support or strut mounted under the wind tunnel model. Research was conducted on the effects of a store at various positions in the wake, as well as the effects of a rear cavity in the …

Modeling, Stability, And Control Of A Rotatable Tail On A Micro Air Vehicle, Travis J. Higgs

Theses and Dissertations

This research uses existing experimental wind tunnel data to develop a non-linear model that is used to characterize the stability of a flexible wing Micro Air Vehicle (MAV) with a rotatable tail. The experimental data are curve fit based on either angle of attack or angle of sideslip, and the coupled effect of tail rotation and tail deflection on the force and moment coefficients. Static optimization trims the input and state variables for Steady Level Unaccelerated Flight (SLUF). The resulting initial conditions are fed to an open loop non-linear Simulink/Matlab simulation. The study found that the bare MAV design is …

Radar - A Novel Admission Control And Handoff Management Scheme For Multimedia Leo Satellite Networks, Syed Rashidali Rizvi

Computer Science Theses & Dissertations

Low Earth Orbit (LEO) satellite networks are deployed as an enhancement to terrestrial wireless networks in order to provide broadband services to users regardless of their location. In addition to global coverage, these satellite systems support communications with hand-held devices and offer low cost-per-minute access cost, making them promising platforms for Personal Communication Services (PCS). LEO satellites are expected to support multimedia traffic and to provide their users with some form of Quality of Service (QoS) guarantees. However, the limited bandwidth of the satellite channel, satellite rotation around the Earth and mobility of end-users makes QoS provisioning and mobility management …

Robust And Efficient Localization Techniques For Cellular And Wireless Sensor Networks, Haseebulla M. Khan

Computer Science Theses & Dissertations

Localization in wireless networks refers to a collection of tasks that, collectively, determines the location of a mobile user, striving to hide the effects of mobility from the user and/or application. Localization has become an important issue and has drawn considerable attention, as many applications including E-911, cargo tracking, locating patients, location-sensitive billing, etc., require knowledge of the location of user/objects. It was realized, quite a while back, that extending emergency 911-like services (E-911) to continually growing mobile population is one of the extremely important localization applications. The bulk of the proposed solutions to emergency location management in wireless environments …

Socio-Economic Analysis Of Fatal Crash Trends (Final Report), Adam Kirk, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

This report describes the analysis of fatal crash patterns and explores the impact of socioeconomic factors and safety regulations on statewide crash rates. This analysis separated statewide crash rates between 2002 and 2004 into two samples, 1) those with crash rates 25 percent greater than the average national rate and 2) those with crash rates lower than this threshold. Safety regulations and socioeconomic factors were identified as having a significant effect on crash rates, with socioeconomic factors showing a higher potential to explain differences in crash rates between the two samples.

Today’S Dot And The Quest For More Accountable Organizational Structures, Lenahan O'Connell, Juita-Elena (Wie) Yusuf, Merl Hackbart, Donald L. Hartman, Candice Wallace, Doug Kreis

Kentucky Transportation Center Research Report

This study investigates the impact of DOT organizational structures on effective transportation planning and performance. A review of the 50 state DOT authorizing statutes and DOT organizational charts found minimal differences in organizational structures among the states. However, 37 states have quasi-independent commissions (sometimes called boards, or councils.) A statistical analysis showed that the commission states have higher Government Performance Project (GPP) scores than the non-commission states. The analysis suggested that effective commissions avoid having members represent geographical regions and political parties and avoid giving the commission the power to select the director of the DOT. In addition the states …

Determination Of Stiffness Matrix Of Tapered Roller Bearings For Vibration Models, Jeeva Kumar

Masters Theses

The stiffness matrix of tapered roller bearings under radial and axial load conditions was evaluated using an analytical model and an experimental approach. An experimental test system was designed and manufactured to determine the radial stiffness of the bearing under combined axial and radial load conditions. A second fixture was designed to measure the stiffness of the bearing under pure axial load conditions. The stiffness coefficients determined have been compared with those obtained from the analytical model, OEM (Original Equipment Manufacturer) data and ABAQUS model (finite element analysis software).

A Qualitative Modeling Method For Platform Design, Michael Van Wie, Robert B. Stone, Asli Sahin, Janis Terpenny, Fabrice Alizon, Steve Shooter, Timothy Simpson

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The development of a collection of related products sharing a common platform represents an important approach in modern product design. an ongoing problem is the application of design methods toward a limited set of evolving product data and archived design knowledge to search and explore alternative platform options. with the goal of maximizing the reuse of end item artifacts and supply chain elements, we propose a design modeling method using basic qualitative relationships among relevant performance, design, and noise parameters in the system of interest. by using qualitative models related to multiple levels of design data, the method provides a …

A Novel Method For Determination Of Dielectric Properties Of Materials Using A Combined Embedded Modulated Scattering And Near-Field Microwave Techniques-Part I: Forward Model, Dana M. Hughes, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The use of combined embedded modulated scattering technique and near-field microwave nondestructive testing techniques is investigated as a novel method for evaluating the dielectric properties of a material. The forward formulation for determining the reflection coefficient at the aperture of a waveguide radiating into a dielectric half-space in which a PIN diode-loaded dipole (i.e., modulated scattering technique probe) is embedded is presented. This formulation is based upon calculating the near-field coupling between the waveguide and the dipole as a mutual impedance.

A Novel Method For Determination Of Dielectric Properties Of Materials Using A Combined Embedded Modulated Scattering And Near-Field Microwave Techniques-Part Ii: Dielectric Property Recalculation, R. Zoughi, Dana Hughes

Electrical and Computer Engineering Faculty Research & Creative Works

The use of combined embedded modulated scattering technique and near-field microwave nondestructive testing techniques is investigated as a novel method for evaluating the dielectric properties of a material. The forward formulation for determining the reflection coefficient at the aperture of a waveguide radiating into a dielectric half-space in which a PIN diode-loaded dipole (i.e., modulated scattering technique probe) is embedded was presented in Part I of this paper. Here, in Part II, the recalculation of the dielectric properties, using the results of the forward model, is presented along with some associated experimental results.

Removal Of Carbonyl Sulfide Using Compost Biofilter: Measurement Of Removal Rates And Elimination Capacity In Conjunction With Hydrogen Sulfide, Divya R. Garrepalli

Civil Engineering Theses - Archive

A lab study using biofiltration was conducted using three PVC columns as biofilters, with hardwood chips and compost as the media. Previous research determined the removal efficiency of carbonyl sulfide alone. (Nawal, 2004) Typically, however H2S is present with COS in the air streams from wastewater treatment plant units. In the current study, different combinations of hydrogen sulfide and carbonyl sulfide gases were tested using H2S/COS ratios typical of the concentrations from wastewater treatment plants. Various runs were conducted using compost and hardwood chips individually and also with an 80:20 ratio by volume of wood chips to compost. The specific …

A K-Epsilon Extension For Wall-Bounded Flows On The Broadband Aeroacoustic System Simulator, David González

Masters Theses

The turbulence modeling capabilities of the Broadband Aeroacoustic System Simulator (BASS), an experimental code developed at NASA Glenn Research Center, have been extended to include wall-bounded flow capabilities. This was done by first validating the code's viscous solving routines by comparing numerical solutions to known, simple analytic solutions. Finally, the dynamics of the wall shear flows were accounted for with the use of wall-damping functions incorporated into the turbulence model. The results for both viscous and turbulence routines agree well with published data.

Mixing Flow Structures Of Scalloped, Forced Lobed Mixers Using Piv And Plif Measuring Techniques, Nathan J. Cooper

Masters Theses

An Experimental study of internal forced lobed mixers similar to those used in jet aircraft engines is performed using whole field species concentration and velocity measuring techniques. Planar temperature and velocity measurements using Planar Laser Induced Fluorescence (PLIF) and 2D Particle Image Velocimetry (PIV) are performed for lobed, lobed scalloped and splitter mixers in aqueous solution. Specific emphasis is given to study scallops or notches cut into the mixer trailing edge and their role in mixing enhancement. Mixing is compared through velocity and species concentration measurements on axial and streamwise planes for the three dimensional, forced mixers in a confined …

Evaluation Of Mechanical Properties Of Self-Consolidating Concrete, Bhusan Basnet

Masters Theses

The concept of Self-Consolidating Concrete is a fresh and rapidly ramping technology in USA, but in some other continents such as Japan and Europe it is in fully fledged stage. The development of this technology has a high potential to economize construction minimizing labor, scheduled time and equipment eliminating consolidation process. In USA, construction professionals are reluctant to its in-effect application because of lack of deliberate and methodological steps for production and applications. The lack of study of its durability characteristics and confusion in design and production process are seems to be vital factors hindering full scale production and application …

Ductile Regime Nano-Machining Of Silicon Carbide, Biswarup Bhattacharya

Masters Theses

This thesis describes experimental work carried out to study the ability to ductile . single point diamond turn both polycrystal Silicon Carbide (SiC) and chemically vapor deposited (CVD) SiC. A Precitech diamond turning machine was used for ductile regime machining of polycrystal SiC at depths of 10 and 25 nm. The possibility of machining SiC in the ductile mode was substantiated by post process analysis of the chips collected during machining and the surface profiles. The force data obtained during machining was recorded and compared later with the different depth of cuts. An investigation into the ability to single point …

Human Error And General Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using Hfacs, Douglas Wiegmann, Troy Faaborg, Albert Boquet, Cristy Detwiler, Kali Holcomb, Scott Shappell

Publications

The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research performed at both the University of Illinois and the Civil Aerospace Medical Institute has successfully shown that HFACS can be reliably used to analyze the underlying human causes of both commercial and general aviation (GA) accidents. These analyses have helped identify general trends in the types of human factors issues and aircrew errors that have contributed to civil aviation accidents. The next step was to identify the exact nature of the human errors identified. …

Evaluation Of High Frequency Ground Penetrating Radar (Gpr) In Mapping Strata Of Dolomite And Limestone Rocks For Ripping Technique, Derek Apel, V. Dezelic

Mining Engineering Faculty Research & Creative Works

This paper presents how high frequency Ground Penetrating Radar (GPR) can be effectively used for mapping the subsurface characterization of dolomite and limestone strata for determination if the rock is suitable for ripping. the results of the experiments conducted in the course of this project illustrated that water saturation helps in increasing the contrast between the dielectric constants of the separations, due to water escaping into cracks and clay layers. Running the survey on a dry rock will give a larger penetration depth; but during the interpretation of the results, one can omit small voids or clay layers. © 2005 …

Green Engineering And Gate-To Gate Life Cycle Assessments For Pharmaceutical Products, Daniel Fichana

Theses and Dissertations

The research of this thesis focused on the environmental and processing metrics during the development of two different drugs. Previous research in life cycle assessments and green engineering have focused on other products and processes, but only a limited amount of studies have been conducted for pharmaceutical applications. This analysis concerned a gate-to-gate analysis of two distinct pharmaceutical products along with the development of a solvent selection table. The goal of this research was to determine how various processing and environmental metrics were affected by process improvements.

The first drug was the pravastatin, which was made via a fermentation route. …

Development, Testing And Evaluation Of Ndor' Tl-5 Aesthetic Open Concrete Bridge Rail, Karla A. Polivka, Ronald K. Faller, James C. Holloway, Dean L. Sicking, John R. Rohde

Nebraska Department of Transportation: Research Reports

No abstract provided.

Fabrication And Mechanical Characterization Of A Two-Ply Cross Fiber Stent And Fibers Comprising Blends Of Poly(L-Lactic Acid), Sushma Gampa

Bioengineering Theses - Archive

Recent studies indicate that stabilization of vulnerable atherosclerotic plaques is critical for minimizing acute coronary syndromes. In this regard a new biodegradable stent design, the Two-ply cross fiber stent, has been developed to reduce stent-imposed stresses on such plaque and to provide increased drug reservoir capability. A comparative study of the mechanical properties of Two-ply and Single-ply stent designs was performed. Fibers comprising PLLA blends were developed and their thermal and mechanical properties were determined. Lateral spreading of helical fibers upon deployment of the Two ply design was observed that, in theory, may reduce stresses on the plaque surface. The …