Digital Commons Network^™

Optimizing Resource Allocation In Eh-Enabled Internet Of Things, Ali Shahini

Dissertations

Internet of Things (IoT) aims to bridge everyday physical objects via the Internet. Traditional energy-constrained wireless devices are powered by fixed energy sources like batteries, but they may require frequent battery replacements or recharging. Wireless Energy Harvesting (EH), as a promising solution, can potentially eliminate the need of recharging or replacing the batteries. Unlike other types of green energy sources, wireless EH does not depend on nature and is thus a reliable source of energy for charging devices. Meanwhile, the rapid growth of IoT devices and wireless applications is likely to demand for more operating frequency bands. Although the frequency …

Storage Systems For Mobile-Cloud Applications, Nafize R. Paiker

Dissertations

Mobile devices have become the major computing platform in todays world. However, some apps on mobile devices still suffer from insufficient computing and energy resources. A key solution is to offload resource-demanding computing tasks from mobile devices to the cloud. This leads to a scenario where computing tasks in the same application run concurrently on both the mobile device and the cloud.

This dissertation aims to ensure that the tasks in a mobile app that employs offloading can access and share files concurrently on the mobile and the cloud in a manner that is efficient, consistent, and transparent to locations. …

Methods To Improve The Remediation Of Polycyclic Aromatic Hydrocarbons (Pahs) In Aerobic And Anaerobic Environments, Brian Wartell

Dissertations

Oil spills occur regularly in terrestrial environments and crude oil can contain many compounds that are highly resistant to degradation. Among these compounds are high levels of polycyclic aromatic hydrocarbons (PAHs) which are not only toxic but can also be carcinogenic and/or mutagenic. The first chapter of this dissertation includes an extensive review chapter on the variables affecting the anaerobic degradation of hydrocarbons, with a particular focus on PAHs. Electron acceptors, electron donors, temperature, salinity, pH all play key roles in determining the possibility effective of effective degradation occurring. Thus, by addressing solutions, such as biostimulation, improving environmental variables for …

High-Speed Data Communications For Vehicular Networks Using Free-Space Optical Communications, Yagiz Kaymak

Dissertations

The demand for high-speed Internet access for vehicles, such as high-speed trains (HSTs) and cars, is on the rise. Several Internet access technologies that use radio frequency are being considered for vehicular networking. Radio-frequency communications technologies cannot provide high data rates due to interference, bandwidth limitations, and the inherent limited data rates of radio technology. Free-space optical communications (FSOC) is an alternative approach and a line-of-sight (LOS) technology that uses modulated light to transfer data between two free-space optical (FSO) transceivers. FSOC systems for vehicular networks are expected to provide data rates in the range of Gbps for stationary and …

Fwer Controlling Procedures In Simultaneous And Selective Inference, Li Yu

Dissertations

With increasing complexity of research objectives in clinical trials, a variety of relatively complex and less intuitive multiple testing procedures (MTPs) have been developed and applied in clinical data analysis. In order to make testing strategies more explicit and intuitive to communicate with non-statisticians, several flexible and powerful graphical approaches have recently been introduced in the literature for developing and visualizing newer MTPs. Nevertheless, some theoretical as well as methodological issues still remain to be fully addressed. This dissertation addresses several important issues arising in graphical approaches and related selective inference problems. It consists of three parts.

In the first …

Functionalized Carbon Nanotubes In Hydrophobic Drug Delivery, Kun Chen

Dissertations

The direct incorporation of carboxylated carbon nanotubes (f-CNTs) into hydrophobic drug particles during their formation via anti-solvent precipitation is presented. The approach is tested using two drugs namely antifungal agent Griseofulvin (GF) and antibiotic Sulfamethoxazole (SMZ) that have very different aqueous solubility. It is observed that the f-CNTs dispersed in the water serve as nucleating sites for crystallization and are readily incorporated into the drug particles without altering crystal structure or other properties. The results show that the hydrophilic f-CNTs dramatically enhance dissolution rate for both drugs. The increased degree of functionalization leads to higher hydrophilicity and therefore faster dissolution …

Deep Learning Methods For Mining Genomic Sequence Patterns, Xin Gao

Dissertations

Nowadays, with the growing availability of large-scale genomic datasets and advanced computational techniques, more and more data-driven computational methods have been developed to analyze genomic data and help to solve incompletely understood biological problems. Among them, deep learning methods, have been proposed to automatically learn and recognize the functional activity of DNA sequences from genomics data. Techniques for efficient mining genomic sequence pattern will help to improve our understanding of gene regulation, and thus accelerate our progress toward using personal genomes in medicine.

This dissertation focuses on the development of deep learning methods for mining genomic sequences. First, we compare …

Development Of Flexible Nickel-Zinc And Nickel-Iron Batteries, Xianyang Meng

Dissertations

The fabrication of flexible nickel-zinc batteries using a facile mixing of electroactive components for electrode preparation is presented. Polytetrafluoroethylene (PTFE) is found to be an effective binder by reducing concentration polarization, providing chemical/physical stability and enhancing flexibility. The zinc electrode containing PTFE maintains its original porous morphology even after hundreds of cycles while polymers such as PEO show morphology change. Each component, as well as the assembled flexible cells show desired flexibility and stability even under bending conditions.

The fabrication of flexible nickel-iron batteries using printable composite electrodes embedded with multiwalled carbon nanotubes (CNT) is also presented. All the metal …

Computational Intelligence In Steganography: Adaptive Image Watermarking, Xin Zhong

Dissertations

Digital image watermarking, as an extension of traditional steganography, refers to the process of hiding certain messages into cover images. The transport image, called marked-image or stego-image, conveys the hidden messages while appears visibly similar to the cover-image. Therefore, image watermarking enables various applications such as copyright protection and covert communication. In a watermarking scheme, fidelity, capacity and robustness are considered as crucial factors, where fidelity measures the similarity between the cover- and marked-images, capacity measures the maximum amount of watermark that can be embedded, and robustness concerns the watermark extraction under attacks on the marked-image. Watermarking techniques are often …

Overcoming Conventional Modeling Limitations Using Image- Driven Lattice-Boltzmann Method Simulations For Biophysical Applications, Olufemi E. Kadri

Dissertations

The challenges involved in modeling biological systems are significant and push the boundaries of conventional modeling. This is because biological systems are distinctly complex, and their emergent properties are results of the interplay of numerous components/processes. Unfortunately, conventional modeling approaches are often limited by their inability to capture all these complexities. By using in vivo data derived from biomedical imaging, image-based modeling is able to overcome this limitation.

In this work, a combination of imaging data with the Lattice-Boltzmann Method for computational fluid dynamics (CFD) is applied to tissue engineering and thrombogenesis. Using this approach, some of the unanswered questions …

The Dynamical State Of A Young Stellar Cluster, Timothy Sullivan

Dissertations

The dynamical state of the young star-forming cluster Rho Ophiuchi is considered, with emphasis on the L1688 cloud. Radial velocities are derived for 32 YSOs, with some being multi-epoch, using Markov-Chain Monte Carlo routines based upon the package emcee. Sources are chosen based upon their spectral index to focus on the earlier stages of star formation, in this case, Class I and Flat spectrum objects, and compared with a sample of Class II and III objects from the same embedded cluster. It is found that the radial velocity dispersion for these younger objects is ∆v = 2.8 ± 0.6 km …

Developing Social And Emotional Skills In Early Childhood Instruction: A Delphi Study, Tess Breen

Dissertations

Purpose: The purpose of this Delphi study was to explore social and emotional learning in early childhood instruction with an emphasis on identifying the methods expert early childhood teachers use to support and promote the development of empathy and emotion regulation, to have the teachers rate the impact of these methods, and to identify the specific activities used to implement the six most highly rated methods.

Methodology: This study utilized the Delphi method which is an iterative process used to collect and distill the judgments of experts using a series of questionnaires interspersed with feedback. Fourteen participants recommended strategies to …

A New Generation Of Functional Polyisobutylenes For Advanced Applications, Corey M. Parada

Dissertations

Polyisobutylene (PIB) is a fully saturated, aliphatic polymer of high commercial importance due to its superior gas barrier properties and high chemical/oxidative stability. One commercial end-use for PIB is in insulated glass windows (IGU), where it acts as a gas/moisture barrier and sealant. Under certain adverse conditions, catastrophic failure of the PIB sealant may result in aesthetic and functional failure of the IGU, which necessitates replacement of the unit. Thus, there exists a need to improve current generations of thermoplastic PIB sealants to be able to withstand the harsh environments found in current real-world applications.

In the first project, we …

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …

A New Keynesian, Neo-Institutional Synthesis: Connecting And Explaining Under-Evaluated Risks In Consumption, Trade, And Finance, Todd Barry

Dissertations

The overall research questions addressed in this dissertation are twofold. First, what are the largest, under-evaluated (or unorthodox) factors that cause growth volatility in both the short and long terms? Second, how can one best determine how much risk is being taken across both of these periods, and how can states increase and/or diversify their risks? The principle hypotheses are that finicky consumerism and structural economic changes, undiversified trade, and under-financed investment contribute significantly to growth volatility. Above all, risk taking actions and policies in countries cause economies to fluctuate. Further, the dissertation suggests that the short-term risk characteristics of …

Mississippi Teacher's Perspectives Of Danielson's Framework For Teaching, Donna Floyd

Dissertations

The focus of this study was to measure Mississippi teacher’s perspectives as identified in the Teacher’s Perspectives on Danielson’s Framework for Teaching (TPDFT) instrument. This quantitative study investigated whether or not statistically significant differences existed between domains as identified in the TPDFT, and if these findings differed statistically as a function of years of teaching experience, type of Mississippi teaching certification, and degree of professional trust. A 36-item survey instrument based on the 2013 version of Charlotte Danielson’s Framework for Teaching was developed. This survey was piloted and distributed to obtain quantitative data to assess teacher’s perspectives on Danielson’s Framework …

Identifying Barriers To Teacher Implementation Of Evidence-Based Practices In Middle-School Reading, Brenda Fortson

Dissertations

This study explores factors that may be related to Mississippi’s 2015 eighth-grade reading scores, which rank the state in 50^th place (Nation’s Report Card, 2016). Whereas there are likely several factors that contribute to middle-school students’ poor performance on the high-stakes tests, this study examines teachers’ reported knowledge and use of evidence-based teaching practices, sense of self-efficacy in implementing the practices, and concerns regarding high-stakes testing and possible relationship with their implementation of the practices.

All public schools in Mississippi were invited to participate in an online survey of sixth-, seventh-, and eighth-grade teachers. After data were screened, 187 …

Effect Of Network Structure On Free Volume And Gas Transport Properties Of Thiol-Ene And Epoxy-Amine Networks, Ramesh Krishnan Ramakrishnan

Dissertations

Network parameters such as cross-link density or intermolecular interactions were used as effective parameters to control polymer chain packing or free volume and thereby control the mass transport properties of networks.

A series of polyethylene glycol (PEG) based thiol-ene elastomeric networks having a broad range of molecular weight between cross-links, M_c, (inverse of cross-link density) was prepared. The specific volume of the networks was studied as a function of temperature and pressure using high pressure dilatometry, and the obtained PVT data was fit using Simha-Somcynsky equation of state (S-S eos) analysis. Fractional free volume, quantified through S-S eos …

Structure-Property Relationships Of Solvent-Cast Organic Thin Films For Model Corrosion Control Coatings, Austin Maples

Dissertations

This dissertation aimed at answering several fundamental questions, specifically: 1) What is the effect of scribing parameters on visual corrosion assessments? 2) What role do molecular weight, residual solvent, and polymer composition have on morphological changes in organic thin films? 3) What alternatives to visual assessments could be implemented to better understand and detect corrosion before macroscopic failure? This research definitively proved that scribes can vary in type and dimensions, and yet are still comparable if the scribe dimensions before exposure are known. Furthermore, it demonstrated that solvents common to a variety of coating industries could become trapped within the …

Computational Modeling Of Radiation Interactions With Molecular Nitrogen, Tyler Reese

Dissertations

The ability to detect radiation through identifying secondary effects it has on its surrounding medium would extend the range at which detections could be made and would be a valuable asset to many industries. The development of such a detection instrument requires an accurate prediction of these secondary effects. This research aims to improve on existing modeling techniques and help provide a method for predicting results for an affected medium in the presence of radioactive materials. A review of radioactivity and the interactions mechanisms for emitted particles as well as a brief history of the Monte Carlo Method and its …

Voluntary Professional Development In Thailand: Teachers’ Motivation, Professional Life Phase, And Contingencies Of Self-Worth, Pongwat Fongkanta

Dissertations

To address the increasing focus on teacher proficiency, professional development opportunities for teachers are routinely provided in Thailand. The focus of this work is on professional development at the individual level and addresses teachers’ motivation for self-improvement and their own worth. Specifically, the purpose of this study was to first validate the relative importance of teachers’ motivation for participating in voluntary professional development and contingencies of self-worth. Secondly, the study sought to determine the relationship of the indicators that contribute to teacher participation with contingencies of self-worth. Lastly, this study examined in what way professional life phase may be related …

Parental Engagement In The Education Of Gifted Children In Saudi Arabia: A Phenomenological Study, Aiman Ali Alyahya

Dissertations

The purpose of this phenomenological study was to explore parents’ perceptions of their experiences engaging in their gifted children’s education in Saudi Arabia. Qualitative research design was utilized, and a phenomenological approach was employed to answer the research questions. Ten Saudi parents were interviewed to explore their engagement in the education of their gifted children. Following thematic analysis, four themes emerged regarding the roles parents played in the engagement of their gifted children’s education. These roles were: Guiding their Gifted Children, Challenging their Gifted Children, Encouraging their Gifted Children, and Advocating for their Gifted Children. Additionally, five themes emerged regarding …

Development And Validation Of Hybrid Continuum/Structural Finite Element Model For Evaluating Foot And Ankle Biomechanics, Saif Alrafeek

Dissertations

Bone is composed of two structures: compact bone and spongy bone. Spongy bone porosity highly affects the strength and the physical endurance of bone to carry loads. Most studies use continuum finite element (FE) approaches to model spongy bone and neglect porosity. Neglecting porosity may not efficiently assist orthopaedic surgeons to treat patients who experience bone physical disability. The purpose of this study is to demonstrate an inexpensive approach that simulates spongy bone with more accurate capturing of porosity and less requirements of bone information. The approach is developed through investigating the mechanical characteristics of spongy bone; that is, by …

Retinex-Based Visibility Enhancement System For Inclement Weather With Tracking And Distance Estimation Capabilities, Marwan S. Alluhaidan

Dissertations

Road conditions affected by weather are well known to have an impact on the number of vehicle accidents and fatalities, due to low- to no-visibility conditions. According to the U.S. Department of Transportation, there are more than 1,259,000 crashes each year. On average, 6,000 people are killed and more than 445,000 people are injured annually due to severe weather conditions. These accidents could be significantly reduced if real-time visibility enhancement systems were made available. However, eliminating the impact of weather conditions on visibility is still lacking and beyond our control. The time has come to develop technology that is capable …

Radiative Double Electron Capture (Rdec) By Fully-Stripped Fluorine Ions In Collisions With Nitrogen, Nuwan Sisira Kumara

Dissertations

Radiative double electron capture (RDEC) by highly-stripped ions in collisions with atomic targets is a fundamental process that can be used to study electron-electron correlation, the interaction between two electrons, in the vicinity of the Coulomb field of a bare ion. In this process two electrons from the target are captured to bound states of the projectile with the simultaneous emission of a single photon. RDEC is closely related to the well-known one-step atomic process of radiative electron capture (REC), in which a target electron is captured to the projectile and a photon is simultaneously emitted. REC and RDEC can …

Exploration Of Post-Secondary Preparation In Urban, Suburban, And Rural High Schools In The State Of Missouri, Rashida J. Mckinley

Dissertations

The purpose of this study was to analyze how high schools in the state of Missouri’s rural, suburban, and urban areas were preparing students for post-secondary education and career readiness. The researcher analyzed the state of Missouri secondary data gathered from the 2013 through 2017 school years, in urban, suburban, and rural high schools. The researcher also surveyed school guidance counselors and administrators. The data represented consisted of ACT Composite Scores, Annual Performance Reports, Post-Secondary Placements, Career and Technical Education Placements, Dropout Rates, and Graduation Rates. This examination utilized a mixed method study to gain an understanding of each school’s …

A Case Study Of The Implementation Of Co-Teaching In A Steam Elementary Magnet School In A Midwestern State, Ashley Lane Copley

Dissertations

Although research is limited on the effectiveness of co-teaching as a service delivery model for students with disabilities, through observation, many educators have reported positive outcomes with co-teaching (Beninghof, 2011). This case study was designed to examine the implementation of co-teaching in an elementary magnet school in a Midwestern school district driven by science, technology, engineering, arts, and mathematics (STEAM) and with a strong emphasis on personalized learning. General education teachers, special education teachers, and administrators were interviewed three times during the initial implementation school year. In addition, journaling was documented by three of the participants, and co-teaching fidelity checks …

Bayesian Estimation Of Mixture Irt Models Using Nuts, Rahab Al Hakmani

Dissertations

The No-U-Turn Sampler (NUTS) is a relatively new Markov chain Monte Carlo (MCMC) algorithm that avoids the random walk behavior that common MCMC algorithms such as Gibbs sampling or Metropolis Hastings usually exhibit. Given the fact that NUTS can efficiently explore the entire space of the target distribution, the sampler converges to high-dimensional target distributions more quickly than other MCMC algorithms and is hence less computational expensive. The focus of this study is on applying NUTS to one of the complex IRT models, specifically the two-parameter mixture IRT (Mix2PL) model, and further to examine its performance in estimating model parameters …

Towards Automated Domain-Oriented Lexicon Construction And Dimension Reduction For Arabic Sentiment Analysis, Hasan A. Alshahrani

Dissertations

Sentiment analysis is a type of text mining that uses Natural Language Processing (NLP) tools to identify and label opinionated text. There are two main approaches of sentiment analysis: lexicon-based, and statistical approach. In our research, we use the lexicon-based approach because the lexicon contains sentiment words and phrases which are the main linguistic units to express sentiments. More specifically, we work with domain-oriented lexicons as they are more efficient than general ones because the polarity is heavily driven by domains.

Arabic language has a degree of uniqueness that makes it hard to be processed with the available cross-language tools …

Generalized Line Graphs, Mohra Abdullah Z. Alqahtani

Dissertations

With every nonempty graph, there are associated many graphs. One of the best known and most studied of these is the line graph L (G) of a graph G, whose vertices are the edges of G and where two vertices of L (G) are adjacent if the corresponding edges of G are adjacent. This concept was implicitly introduced by Whitney in 1932. Over the years, characterizations of graphs that are line graphs have been given, as well as graphs whose line graphs have some specified property. For example, Beineke characterized graphs that are line graphs by forbidding certain graphs …