Engineering Commons^™

Studies In The Use Of Time Into Utterance As A Predictive Feature For Language Modeling, Nigel Ward, Alejandro Vega

Departmental Technical Reports (CS)

In (Ward and Vega 2008) we examined how how word probabilities vary with time into utterance, and proposed a method for using this information to improve a language model. In this report we examine some ancillary issues in the modeling and exploitation of these regularities.

Functional Specification And Verification Of Object-Oriented Programs, Yoonsik Cheon

Departmental Technical Reports (CS)

One weakness of Hoare-style verification techniques based on first-order predicate logic is that reasoning is backward from postconditions to preconditions. A natural, forward reasoning is possible by viewing a program as a mathematical function that maps one program state to another. This functional program verification technique requires a minimal mathematical background as it uses equational reasoning based on sets and functions. Thus, it can be easily taught and used in practice. In this paper, we formalize a functional program specification and verification technique and extend it for object-oriented programs. Our approach allows one to formally specify and verify the behavior …

Spatial And Temporal Temperature Distributions In Municipal Solid Waste Landfills, James L. Hanson, Nazli Yesiller, Nicolas K. Oettle

Civil and Environmental Engineering

Long-term spatial and temporal variations in temperatures have been investigated in covers, wastes, and liners at four municipal solid waste landfills located in different climatic regions: Alaska, British Columbia, Michigan, and New Mexico. Temperatures were measured in wastes with a broad range of ages from newly placed to old (up to 40 years). The characteristic shape of waste temperature versus depth relationships consisted of a convex temperature profile with maximum temperatures observed at central locations within the middle third fraction of the depth of the waste mass. Lower temperatures were observed above and below this central zone, with seasonal fluctuations …

Compaction Characteristics Of Municipal Solid Waste, James L. Hanson, Nazli Yesiller, Shawna A. Von Stockhausen, Wilson W. Wong

Civil and Environmental Engineering

Compaction characteristics of municipal solid waste (MSW) were determined in the laboratory and in the field as a function of moisture content, compactive effort, and seasonal effects. Laboratory tests were conducted on manufactured wastes using modified and 4X modified efforts. Field tests were conducted at a MSW landfill in Michigan on incoming wastes without modifications to size, shape, or composition, using typical operational compaction equipment and procedures. Field tests generally included higher efforts and resulted in higher unit weights at higher water contents than the laboratory tests. Moisture addition to wastes in the field was more effective in winter than …

Intricacies Of Professional Certifications For Quality Management (Qm), Edmund R. Martelli

Masters Theses & Specialist Projects

The modern manufacturing marketplace is extremely complex and constantly changing. Career professionals often seek job placement, career advancement, and continuing education through professional certifications. Professional certifications in the United States (U.S.) have been evolving since 1911. In the 1950s, engineering groups established professional certifications and licenses. In the 1980s, administration of accreditation of certification programs proliferated, and by the 1990s, many government and professional organizations sought to standardize procedures for the industry. Currently, professional certifications are available for virtually every profession and issued by multitudes of organizations.

Quality management (QM) encompasses an extensive combination ofprofessional abilities. Providers of professional certifications …

Integrating Recommender Information In Social Ecosystems Decisions, Renato A C Capuruco, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

The exploration of online social networks whose members share mutual recommendations and interactions is a time-dependent and contextual-based process which aims to predict the social status among members, ultimately improving the network's discoverability to achieve societal gain. To address the difficulties associated with the process, this article presents an integrated recommender model whose statements are time-dependent, interaction-aware, and social context-sensitive. The originality of the proposed model stems from the integration of the predictive recommender, social networks, and interaction components. Each model is developed based on: (1) a time history and decay algorithm to consider the decreasing intensity of recommendations among …

An Empirical Study On The Procedure To Derive Software Quality Estimation Models, Jie Xu, Danny Ho, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

Software quality assurance has been a heated topic for several decades. If factors that influence software quality can be identified, they may provide more insight for better software development management. More precise quality assurance can be achieved by employing resources according to accurate quality estimation at the early stages of a project. In this paper, a general procedure is proposed to derive software quality estimation models and various techniques are presented to accomplish the tasks in respective steps. Several statistical techniques together with machine learning method are utilized to verify the effectiveness of software metrics. Moreover, a neuro-fuzzy approach is …

Seismic Assessment Of An Existing Non-Seismically Designed Major Bridge-Abutment-Foundation System, Aman Mwafy, Oh Sung Kwon, Amr Elnashai

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A comprehensive study carried out to assess the seismic response of a 59-span bridge using a refined inelastic modeling approach and considering Soil-Structure Interaction (SSI) is summarized in this paper. the focus is on describing the methodology adopted to idealize the bridge and its foundation system, while only highlights from the extensive elastic and inelastic analyses are presented. the bridge represents a typical case of vulnerable complex bridges since it was built in the early seventies with minimal seismic design requirements at a distance of about 5 km from a major fault. the SSI analysis is significant in this study …

Newsletter 42 Issue 2 - Summer 2010 - Nuts And Bolts, Tractor Museum

Friends of the Larsen Tractor Museum

No abstract provided.

Non-Contact Spatially Constrained Optical Scanning Methods Applied For Depth, Width And Gap Measurements, Konda Reddy Thotti Reddy

All Theses

The thesis presents the non-contact laser projection based systems utilized for quantifying the feature dimensions like width, depth and air gaps. Laser diode, Charge coupled device (CCD) and post-processing software using image processing tools are the major components of the non-contact measurement systems. The study involves two methods where the first method comprises of active laser-based triangulation and morphological edge detection for depth and width measurement applications. The second method uses edge detection technique and Dynamic Field of View (DFOV) for gap detection and tracking. Using the developed techniques, the case studies are conducted with smooth plastic fenders with induced …

Diffuse Ultrasonic Scattering In Advanced Composites, Christer Stenström

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Non destructive testing (NDT) is a noninvasive technique used for characterization and inspection of the integrity of objects. NDT is an important tool for research, manufacturing monitoring and in-service inspections. Ultrasonic testing is the most used NDT technique, which for advanced composites can identify several types of defects, like delamination and interlaminar cracks. Diffuse ultrasonics has shown to be able to extract information at the microscale of metals and therefore it is believed it can be used for advanced composites to extract microstructural information, i.e. at the level of fibers.

In this thesis, diffuse ultrasonic methods, together with spatial variance …

Why Ellipsoid Constraints, Ellipsoid Clusters, And Riemannian Space-Time: Dvoretzky's Theorem Revisited, Karen Villaverde, Olga Kosheleva, Martine Ceberio

Departmental Technical Reports (CS)

In many practical applications, we encounter ellipsoid constraints, ellipsoid-shaped clusters, etc. A usual justification for this ellipsoid shape comes from the fact that many real-life quantities are normally distributed, and for a multi-variate normal distribution, a natural confidence set (containing the vast majority of the objects) is an ellipsoid. However, ellipsoid appear more frequently than normal distributions (which occur in about half of the cases). In this paper, we provide a new justification for ellipsoids based on a known mathematical result -- Dvoretzky's Theorem.

Towards An Efficient Bisection Of Ellipsoids, Paden Portillo, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

Constraints are often represented as ellipsoids. One of the main advantages of such constrains is that, in contrast to boxes, over which optimization of even quadratic functions is NP-hard, optimization of a quadratic function over an ellipsoid is feasible. Sometimes, the area described by constrains is too large, so it is reasonable to bisect this area (one or several times) and solve the optimization problem for all the sub-areas. Bisecting a box, we still get a box, but bisecting an ellipsoid, we do not get an ellipsoid. Usually, this problem is solved by enclosing the half-ellipsoid in a larger ellipsoid, …

On Nonlinear Response Of Micro And Nano Capacitive Resonators, Martin William Knecht

Theses and Dissertations - UTB/UTPA

The nonlinear response of an electrostatically actuated micro/nano-resonator is investigated. The resonator is parametrically actuated using an electrostatic force with a first order fringe correction. Viscous damping and the Casimir effect are included. The resonator is studied using the Method of Multiple Scales in a direct approach of the problem and then compared numerically using a Reduced Order Model based on the application of a Galerkin procedure. In addition to primary resonance (ω0), parametric resonances are found at half (½ω0), twice (2ω 0), and three-halves ([special characters omitted]ω0) natural frequency. The frequency response is investigated for excitations near primary and …

Combined Musculo-Skeletal Multi-Body Dynamics/Finite Element Analysis Of Several Ergonomics And Bio-Mechanics Problems, Xin Xie

All Theses

Within this thesis, two ergonomics (i.e. seating comfort and long-distance driving fatigue problems) and two structural bio-mechanics (i.e. femur-fracture fixation and radius-fracture fixation) problems are investigated using musculo-skeletal multi-body dynamics and finite element computational analyses.
Within the seating comfort problem analyzed, a complete-body finite element model is constructed and used to assess the effect of seat geometry and seating posture on the feel of comfort experienced by a seated human.
Within the long-distance driving fatigue problem, musculo-skeletal analysis is employed to assess the extent of fatigue experienced by a driver through the evaluation of level of activity of his/her various …

Selection Of Channel-Access And Routing Protocols For Mobile Ad Hoc Networks With Frequency-Agile Radios And Directional Antennas, Rebekah Schloemann

All Theses

In this thesis, ad hoc networks with frequency-agile radios utilizing omni-directional and directional antennas form the basis of study. This work focuses on the selection of channel-access and routing protocols for these networks. Findings demonstrate that protocol selection must occur jointly in order to increase the efficient utilization of available spectrum while achieving maximum network performance.
In this thesis, we investigate several channel-access methods that provide different ways of selecting one of the heterogeneous non-overlapping channels for transmission. We also investigate a modification of least-resistance routing that accounts for the variations in transmission channels. Through simulation, we find that better …

Microstructure Modification Of Cu0.2ag2.8sbsete2 Through, Sloan Lindsey

All Theses

Cu0.2Ag2.8SbSeTe2 is new potential thermoelectric compound that exhibits very low thermal conductivity and a region of glass-like thermal conductivity. The compound phase segregates into AgSbTe2 and Ag2Te phases with Se and Cu acting as isoelectronic dopants. Backscatter SEM imaging is used to study the resulting microstructure. Normally cast samples exhibit cracks forming near the interfaces of the two phases. In this work we show that the cracks are caused by a low temperature monoclinic to cubic phase transition that occurs in the Ag2Te phase. We demonstrate that through rapid quenching we can control the size and shape of the phase …

Synthesis Of Higher-Order K-Delta-1-Sigma Modulators For Wideband Adcs, Vishal Saxena, R. Jacob Baker

Electrical and Computer Engineering Faculty Publications and Presentations

As CMOS technology shrinks, the transistor speed increases enabling higher speed communications and more complex systems. These benefits come at the cost of decreasing inherent device gain, increased transistor leakage currents and device mismatches due to process variations. All of these drawbacks affect the design of high-resolution analog-to-digital converters (ADCs) in nano-CMOS processes. To move towards an ADC topology useful in nano-CMOS, the K-Delta-1-Sigma (KD1S) modulator-based ADC was proposed. This paper extends the KD1S to higher order topologies using a systematic synthesis procedure. Second and third order KD1S modulator are designed and simulated to demonstrate the synthesis method.

Indirect Compensation Techniques For Three-Stage Fully-Differential Op-Amps, Vishal Saxena, R. Jacob Baker

Electrical and Computer Engineering Faculty Publications and Presentations

As CMOS technology continues to evolve, the
supply voltages are decreasing while at the same time the transistor threshold voltages are remaining relatively constant. Making matters worse, the inherent gain available from the nano-CMOS transistors is dropping. Traditional techniques for achieving high-gain by cascoding become less useful in nano-scale CMOS processes. Horizontal cascading (multi-stage) must be used in order to realize high-gain op-amps in low supply voltage processes. This paper discusses indirect compensation techniques for op-amps using split-length devices. A reversed-nested indirect compensated (RNIC) topology, employing double pole-zero cancellation, is illustrated for the design of three-stage op-amps. The RNIC topology …

Bottom Flange Reinforcement In Nu I-Grinders, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Structural Bioinformatics Based Method For Predicting The Initial Adsorbed Protein Orientation On A Surface, Aby Thyparambil

All Theses

In any molecular simulation of protein-surface interaction, the selection of the initial orientation with which the protein would interact with the surface must be first made and is found to be critical in the determination of the bioactive state of the adsorbed protein. While various molecular simulation methods have been developed to identify the preferred orientation, these methods are generally computationally expensive and time consuming, especially for large molecules thereby motivating the current study.
The computational implementation for identifying a preferred orientation was done in MATLAB¨ and directly addresses the current research problem by assuming the protein to be rigid …

The Use Of A-Flute, B-Flute, Ac-Flute, And Bc-Flute Corrugated Paperboard As A Cushioning Material, Alicia Campbell

All Theses

Corrugated paperboard, often referred to as cardboard by those outside the
industry, is most often associated with the typical shipping box. Research has proven that cushioning is another possible packaging application for corrugated paperboard.
Corrugate is easily accessed, obtained from a renewable resource, and easily recycled all of which appeal to the increased interest in the use of sustainable materials. Most research related to corrugate as a cushioning material has been performed using
single-wall, C-flute corrugated paperboard.
The purpose of this research was to create cushion curves for A-flute, B-flute,
AC-flute, and BC-flute corrugated paperboard using the stress energy method. …

Development Of A Low Cost, Energy-Absorbing Bridge Rail, Dean L. Sicking, Robert W. Bielenberg, Ronald K. Faller, Karla A. Lechtenberg, Scott K. Rosenbaugh, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Determination Of Higher Order Coefficients For A Crack Parallel To An Interface, Venkata Lakshman Kolluru

All Theses

A general method based on the singular integral equations is developed to
computationally determine the higher order coefficients in mixed mode fracture
mechanics. These 'k' and 'T' coefficients are defined with respect to a polar coordinate
system centered at a crack tip, and give asymptotic expressions for stresses and
displacements according to the William's eigenfunction expansions,
(r, ) (2r) k f (n, ) k f (n, ) IIk
ij
II
n
Ik
ij
I
n
n 0
2
1
n
ij      



1
(0, ) (2 ) ( , ) ( , …

An Investigation Of The Response Of Incandescent Lamps And Compact Fluorescent Lamps To Voltage Fluctuation, Christopher May

All Theses

This thesis presents the results of tests that were performed on incandescent lamps and compact fluorescents lamps (CFLs) in order to observe their sensitivity to voltage fluctuations that can occur on a power system. The lamps tested were designed for use in a 120V, 60Hz system. They are models that are commonly available in the United States.
In this research, the lamps in question were exposed to four separate tests. The first set of tests analyzed the response of each lamp to a series of long voltage fluctuations that were applied long enough to allow the light output from the …

Eight-Channel Reconfigurable Microring Filters With Tunable Frequency, Extinction Ratio And Bandwidth, Hao Shen, Maroof H. Khan, Li Fan, Lin Zhao, Yi Xuan, Jing Ouyang, Leo T. Varghese, Minghao Qi

Birck and NCN Publications

We demonstrate an eight-channel reconfigurable optical filter on a silicon chip. It consists of cascaded microring resonators and integrated compact heaters. With an embedded Mach-Zehnder (MZ) arm coupling to a microring resonator, the important parameters of a filter such as center frequency, extinction ratio and bandwidth can be controlled simultaneously for purposes of filtering, routing and spectral shaping. Thus our device could potentially be useful in dense wavelength division multiplexing (DWDM) and radio frequency arbitrary waveform generation (RFAWG). Multichannel filter response was successfully tuned to match the International Telecommunication Unit (ITU) grid with 50, 100 and 200GHz in channel spacing. …

Acoustic Phonon Scattering In Bi2te3/Sb2te3 Superlattices, Yaguo Wang, Carl Liebig, Xianfan Xu, Rama Venkatasubramanian

Birck and NCN Publications

Ultrafast time-resolved measurements were conducted to investigate long-wavelength acoustic phonon scattering and velocity reduction in Bi2Te3/Sb2Te3 superlattices. We show that both these phenomena suppress heat transfer process, with the phonon scattering contributing more in differentiating the lattice thermal conductivities among films with different periods. Measurements of reduction in the acoustic phonon amplitudes support the decrease in the thermal conductivity for certain superlattice periods, which is not predicted by acoustic mismatch theory. This study is a direct measurement of coherent acoustic phonons in superlattices which is of significant interest to thermoelectrics.

Iii-Nitride Nanopyramid Light Emitting Diodes Grown By Organometallic Vapor Phase Epitaxy, Isaac Wildeson, Robert Colby, David Ewoldt, Zhiwen Liang, Dmitri Zakharov, Nestor J. Zaluzec, R. Edwin García, E A. Stach, Timothy D. Sands

Birck and NCN Publications

Nanopyramid light emitting diodes (LEDs) have been synthesized by selective area organometallic vapor phase epitaxy. Self-organized porous anodic alumina is used to pattern the dielectric growth e templates via reactive ion etching, eliminating the need for lithographic processes. (In,Ga)N quantum well growth occurs primarily on the six {1 (1) over bar 01} semipolar facets of each of the nanopyramids, while coherent (In,Ga)N quantum dots with heights of up to similar to 20 nm are incorporated at the apex by controlling growth conditions. Transmission electron microscopy (TEM) indicates that the (In,Ga)N active regions of the nanopyramid heterostructures are completely dislocation-free. Temperature-dependent …

Metric Signature Transitions In Optical Metamaterials, Igor Smolyaninov, Evgenii Narimanov

Birck and NCN Publications

We demonstrate that the extraordinary waves in indefinite metamaterials experience an (- - + +) effective metric signature. During a metric signature change transition in such a metamaterial, a Minkowski space-time is created together with a large number of particles populating the space-time. Such metamaterial models provide a tabletop realization of metric signature change events suggested to occur in Bose-Einstein condensates and quantum gravity theories.

Facial Expression Recognition System, Ewa Piatkowska

Technical Reports

This thesis describes the problem of facial expression recognition in the field of computer vision. Firstly, the psychological background of a problem is presented. Then, the idea of facial expression recognition system (FERS) is outlined and the requirements of such system are specified. The FER system consists of 3 stages: face detection, feature extraction and expression recognition. Methods proposed in literature are reviewed for each stage of a system. Finally, the design and implementation of my system are explained. The face detection algorithm used in the system is based on work by Viola and Jones [13]. The expressions are described …