Digital Commons Network^™

Characterization Of Soil Variability For Reliability-Based Design, Sitenikechukwu Onyejekwe

Doctoral Dissertations

"A very carefully planned Missouri-wide field exploration and laboratory investigation program, with a focus on fine-grained soils, was executed with the aim of characterizing the variability of geotechnical parameters statistically with a view to increasing the use of reliability-based design (RBD) among geotechnical engineers. Geotechnical parameters were characterized in terms of both their first and second statistical moments and their coefficient of variation (COV). Their probability distributions and their scale of fluctuation, θ, were also determined. Correlations between difficult-to-obtain parameters and more easily-obtained parameters were developed and the degree of fit of study data to published empirical correlations was investigated. …

Wavelet Based Contrast Limited Histogram Equalization For Contrast Enhancement Of Digital Mammography, Ashish Vighnahar Avachat

Masters Theses

"Mammography has been the most efficient tool for screening of microcalcification and cancer tissues; however, the raw images produced by mammography systems are usually of poor contrast. In order to use these raw images for early diagnosis; their contrast, sharpness and noise need to be enhanced. Among these important enhancement parameters contrast enhancement is critical. A novel algorithm is introduced which blends wavelet transforms with Contrast Limited Adaptive Histogram Equalization (CLAHE) for contrast enhancement. In this algorithm, the input image is decomposed to its low frequency and high frequency components in wavelet domain. Decomposed coefficients from different bands are then …

Spiking Neural Networks Encoding And Decoding Algorithms For Time Series Estimation And System Identification, Sinchan Roychowdhury

Masters Theses

"Artificial Neural networks (ANNs) have increasingly been applied to different system identification, pattern recognition and function approximation problems. The predominantly used neural network architectures are the feedforward and feedback networks. Multilayer perceptrons and radial basis function networks are among the most commonly used feed-forward architecture neural networks and the Elman and Jordan networks are the most widely used recurrent neural networks. These networks are also called as second generation ANNs.

This thesis focuses on the third generation ANNs which are biologically inspired and operate on the same principles as the living neurons. These are also known as biologically inspired artificial …

Sieve Bootstrap Based Prediction Intervals And Unit Root Tests For Time Series, Maduka Rupasinghe

Doctoral Dissertations

"The application of the sieve bootstrap procedure, which resamples residuals obtained by fitting a finite autoregressvie (AR) approximation to empirical time series, to obtaining prediction intervals for integrated, long-memory, and seasonal time series as well as constructing a test for seasonal unit roots, is considered. The advantage of this resampling method is that it does not require knowledge about the underlying process generating a given time series and has been shown to work well for ARMA processes. We extend the application of the sieve bootstrap to ARIMA and FARIMA processes. The asymptotic properties of the sieve bootstrap prediction intervals for …

Search-Based System Architecture Development Using A Holistic Modeling Approach, Renzhong Wang

Doctoral Dissertations

"This dissertation presents an innovative approach to system architecting where search algorithms are used to explore design trade space for good architecture alternatives. Such an approach is achieved by integrating certain model construction, alternative generation, simulation, and assessment processes into a coherent and automated framework. This framework is facilitated by a holistic modeling approach that combines the capabilities of Object Process Methodology (OPM), Colored Petri Net (CPN), and feature model. The resultant holistic model can not only capture the structural, behavioral, and dynamic aspects of a system, allowing simulation and strong analysis methods to be applied, it can also specify …

The Characterization Of Volatiles Associated With Young Stellar Objects, Kari Anne Wojtkowski

Doctoral Dissertations

In the first portion of this work, we searched for differences in volatiles within a single star forming region, Rho Ophiuchi. We determined the amount, temperature, and composition of two ice features, the bending modes of CO₂ and H₂O at 15 µm and 6 µm, respectively, toward 28 Young Stellar Objects (YSOs). We found that more than 50% of the YSOs studied contained a portion of crystalline CO₂ ice. We also found that some sources with Flat or borderline Class II Spectral Energy Distributions (SEDs) have a larger abundance of CO₂ ice with respect to H₂O ice. In addition to …

Modeling And Synthesis Of Pvdf-Based Dielectrics For Energy Storage Applications, Xuhui Lu

Doctoral Dissertations

"The purpose of this research was to develop dielectric films for high energy density capacitor applications. Also desired was to develop a deeper understanding of dielectric breakdown and electric energy storage related phenomena through simulation, theoretical analysis, and experimental investigation.

An analytical model incorporating Weibull dielectric strength statistics was developed to establish quantitative relationships between material properties and device performance of self-healing capacitors. The model is useful for designing high voltage capacitors and developing dielectric materials where the effects of electric field-dependent permittivity need to be considered.

In the experimental work, solution-cast poly(vinylidene difluoride) (PVDF) homopolymer PVDF films with high …

The Effect Of Sulfur On Structure And Conversion Of Bioactive Borate Glasses, Ali Mohammadkhah

Masters Theses

"The effect of sulfur on glass structure and the conversion process of bioactive CaO-LI₂O-B₂O₃ glasses were studied. One glass without and two glasses with different amounts of sulfur were made using conventional melting and dry quenching techniques. These glasses reacted with a phosphate solution and converted to hydroxyapatite. Particles (150-355µm) were reacted in 0.25 and 0.5 molar K₂HPO₄ solutions at 37⁰C for 2 to 96 hours. The weight loss of the particles and the final pH of the solution were measured. The weight loss measurements indicated that the reaction rate increases with …

Sapphire Fiber Numerical Aperture Measurement And Sensor Fabrication, Xia Fang

Masters Theses

"A sapphire fiber is made of single crystal aluminum oxide with hexagonal crystal structure. It is attractive for high temperature application for its chemical resistance and high melting point of 2053⁰C. It is good for infrared transmission with a small attenuation of 0.13dB per meter at the wavelength of 2.94µm, and it can also deliver very high optical energy. However, a typical sapphire fiber has a rough surface and a nonperfect crystalline structure. Also, a sapphire fiber cannot be grown in a core-clad structure. The un-cladded waveguide imposes a number of undesirable characteristics on sensing applications, e.g., unpredictable light loss …

Geomechanical Characterization Of Reservoir & Cap Rocks For Co₂ Sequestration, Sudarshan Govindarajan

Masters Theses

"Geological sequestration of CO₂ has been identified as one method to reduce global emissions of CO₂ and achieve lower levels of CO₂ concentrations in the atmosphere. Geological formations have to be assessed in terms of their capacity, sealing capabilities and economic feasibility before CO₂ sequestration can commence. Potential leakage of injected CO₂ from the reservoir formation could occur due to natural or injection induced faults or fractures in the reservoir or sealing formations. As part of a potential leakage investigation a geomechanical characterization which refers to the assessment of the in-situ stress conditions, rock strength and stiffness properties of the …

Effects Of High Volumes Of Fly Ash On Cement Paste, Karl Wehking Beckemeier

Masters Theses

"The study of high-volume fly ash (HVFA) concrete mixtures has become popular due to the significant environmental and economic benefits which the material may provide. By including fly ash at 50 percent or greater replacement levels, substantial benefits could be obtained. However, the inclusion of fly ash can have negative effects, including incompatibilities between constituents of a mixture. As the fly ash replacement level increases, the degree and likelihood of these problems increases.

In this study, paste mixtures were made, as part of a larger HVFA concrete study, in order to determine the degree to which varying levels of fly …

Transport Of A Methamphetamine Surrogate Through Painted Drywall And Accumulation In Insulation, Nishanthini Vijayakumar Shakila

Masters Theses

"Methamphetamine is a drug of abuse in the United States and it is frequently produced in residential "meth labs." During a specific cooking stage called "salting out", a high concentration of methamphetamine is released into the air and can accumulate on and within indoor surfaces. Even after remediation, methamphetamine and other chemicals can be released into the occupied space by diffusion and desorption from insulation and painted drywall. To better understand the emission characteristics of methamphetamine, the diffusion coefficient of n- isopropylbenzylamine (NIBA; an isomer and surrogate for methamphetamine) was measured in latex painted drywall. To quantify the diffusion coefficient, …

Synthesis Of Nickel Nanoparticles By Gamma-Radiation And Femtosecond Laser Ablation, Vivek Murlidhar Rao

Masters Theses

"Nickel nanoparticles were synthesized by gamma-radiation and femtosecond laser ablation. Aqueous precursors were prepared by uniformly dispersing nickel chloride in a 2:1 ratio of water and isopropanol. Stabilizers employed were Sodium Dodecyl Sulfate (SDS) and Poly Vinyl Pyrrolidone (PVP). Gamma-ray radiolysis of aqueous nickel precursors was investigated as a reducing agent for nickel cations to form atomic seeds for nucleation on multi-walled carbon nanotubes (MWCNTs). 30-60kGy was the dosage used in increments of 10kGy, at a rate of 10kGy/hr. Isopropanol was added to consume the excess of oxidizing species produced by irradiation and form stable secondary radicals. The influence of …

Cooperative Power Control Approaches Towards Fair Radio Resource Allocation For Wireless Network, Liuju Wu

Masters Theses

"Performance optimization in wireless networks is a complex problem due to variability and dynamics in network topology and density, traffic patterns, mutual interference, channel uncertainties, etc. Opportunistic or selfish approaches may result in unbalanced allocation of channel capacity where particular links are overshadowed. This degrades overall network fairness and hinders a multi-hop communication by creating bottlenecks. A desired approach should allocate channel capacity proportionally to traffic priority in a cooperative manner. This work consists of two chapters that address the fairness share problem in wireless ad hoc, peer-to-peer networks and resource allocation within Cognitive Radio network. In the first paper, …

5-Axis Tool Path Generation With Collision Detection For Finish Machining Of Freeform Surfaces, Jomy Francis

Masters Theses

"Research in the field of Tool path generation for freeform surfaces has been done intensively in the past. However, the main challenge that still exists is the computational efficiency related to the tool path generation. Tool path generation for freeform surface involves instantaneous calculation of new tool orientations which does not collide with the neighboring surfaces. Since the collision check of tool and neighboring surface is done repetitively at every instant of the tool, the calculations at every instant are to be computationally as easy as possible.

This thesis is composed of one paper. Paper I presents a novel extension …

Behavior Of Staged Externally Bonded Carbon Fiber Reinforced Polymer Sheets For Improved Ductility, Laura Marie Rathe

Masters Theses

"Fiber reinforced polymers (FRP) has become increasingly used for the retrofit of aging structures for increased lifespans and for the rapid repair of damaged structures. It has many advantageous such as ease in rapid installation, high strength-to-weight ratio, and corrosion resistance. The main disadvantage of the material is brittle behavior with little warning of impending failures. The main objective of this study is to develop a new system of FRP that exhibits a more ductile behavior. To achieve this objective, separate sheets of FRP were applied at various staged levels and thus engaged at different loads. Ductile behavior was evaluated …

Module-Level Power Converters For Parallel Connected Photovoltaic Arrays, Zachary Scott Johnson

Masters Theses

"A new solar technology with the capability to increase array-level power production is introduced by using simple integrated power converters that connect directly to photovoltaic (PV) panels is investigated. The power converters proposed here are full-bridge DC-DC converters with high voltage gain that operate with an open-loop control scheme. The outputs of these converters could then be directly connected to a grid-tie converter eliminating the need to connect panels in series to achieve the appropriate voltage. With a high-efficiency converter, the total system efficiency would increase even though one panel in the array may be compromised. The simulation results show …

The Use Of Electrical Resistivity Tomography (Ert) To Delineate Water-Filled Vugs Near A Bridge Foundation, Jeremiah Chukwunonso Obi

Masters Theses

"A structural support was needed to strengthen the load-bearing capacity of an unnamed bridge foundation in Laclede County in South-Central Missouri due to increasing traffic volume and age of the bridge. This area is characterized by karstic features such as losing streams, underground caves and sinkholes. During the construction of a drilled shaft for the substructure, a few feet north of the north footing of the pier, voids were noted beneath a roughly 2 foot thick cap of dolomite rock. Because of this, there were concerns about the integrity of the rock beneath the existing bridge foundation. Consequently, subsurface investigation …

College Of Education Annual Report And Findings, Fiscal Year 2011, College Of Education, Illinois State University

Annual Report and Findings

No abstract provided.

The Clarion, 2012, University High School

Yearbooks

The Clarion of University High School, Normal, Illinois, 2012.

Comment: A Minor Conflict: Why The Objectives Of Federal Sex Trafficking Legislation Preempt The Enforcement Of State Prostitution Laws Against Minors, Susan Crile

American University Law Review

No abstract provided.

Note: "Standing" In The Way Of Equality? The Myth Of Proponent Standing And The Jurisdictional Error In Perry V. Brown, Andrew Kim

American University Law Review

No abstract provided.

Outfoxing Alaska Hunters: How Arbitrary And Capricious Review Of Changing Regulatory Interpretations Can More Efficiently Police Agency Discretion, Brian J. Shearer

American University Law Review

No abstract provided.

Article Iii Judicial Power And The Federal Arbitration Act, Roger J. Perlstadt

American University Law Review

No abstract provided.

Text And Pretext: The Future Of Material Witness Detention After Ashcroft V. Al-Kidd, Catherine Cone

American University Law Review

No abstract provided.

The Folly Of Rule 14a-11: Business Roundtable V. Sec And The Commission's Next Step, Stephanie Lyn Parker

American University Law Review

No abstract provided.

Using Automatic Speech Recognition Technology With Elicited Oral Response Testing, Troy L. Cox, Randall S. Davies

Faculty Publications

This study examined the use of automatic speech recognition (ASR) scored elicited oral response (EOR) tests to assess the speaking ability of English language learners. It also examined the relationship between ASR-scored EOR and other language proficiency measures and the ability of the ASR to rate speakers without bias to gender or native language. To that end, 179 subjects were given an ASR-scored EOR test with 60 items, followed by an oral proficiency interview (OPI) type assessment and a battery of other language tests. Findings suggest that ASR-scored EOR results could be used alone to predict speaking ability in specific …

Red Note New Music Festival Program, 2012, School Of Music

Red Note New Music Festival

The RED NOTE New Music Festival at Illinois State University is a week-long event which features outstanding performances of contemporary concert music.

Low Frequency Temperature Variability And Native American Horticulture In The Northern Southwest And Eastern Great Basin, James R. Allison

Faculty Publications

Recent paleoclimatic studies reconstruct low-frequency variability in temperature that may have affected the success of Native American horticulture. Potential effects of this temperature variability include shifts in the range of elevations within which horticulture was viable, and changes in the northern limits of horticulture- based economies. This paper examines radiocarbon dates and other chronological data from Fremont and Puebloan sites in Utah, eastern Nevada, and northwestern Arizona, comparing the low-frequency temperature reconstructions with the timing of expansion and contraction in the northern frontier of maize horticulture and temporal shifts in the elevations of farming settlements.

Impacts Of A Parenting Newsletter On Fathers Of Kindergarten Children, Sean E. Brotherson, Erin Kramer Holmes, Christopher J. Bouwhuis

Faculty Publications

This study is the first assessment of the perceived effectiveness of a parenting newsletter written specifically for fathers or father figures. The Father Times newsletter was distributed weekly for six weeks to all families of kindergarten children at a local school. Once hundred seventy-seven fathers responded to a self-report questionnaire regarding usage of the parenting newsletter, perceptions of the newsletter as a resource, and impacts of fathers' attitudes, knowledge, behaviors, and father–child relationship quality. Two-thirds of fathers in the sample reported changing at least "somewhat" in all nine outcomes explored. Neither father age nor number of children in the home …