Physical Sciences and Mathematics Commons^™

Impact Of Gamma-Irradiation On The Characteristics Of Iii-N/Gan Based High Electron Mobility Transistors, Anupama Yadav

Electronic Theses and Dissertations

In this study, the fundamental properties of AlGaN/GaN based High Electron Mobility Transistors (HEMTs) have been investigated in order to optimize their performance in radiation harsh environment. AlGaN/GaN HEMTs were irradiated with 60Co gamma-rays to doses up to 1000 Gy, and the effects of irradiation on the devices' transport and optical properties were analyzed. Understanding the radiation affects in HEMTs devices, on carrier transport, recombination rates and traps creation play a significant role in development and design of radiation resistant semiconductor components for different applications. Electrical testing combined with temperature dependent Electron Beam Induced Current (EBIC) that we used in …

A Comparison Of Concurrent Correctness Criteria For Shared Memory Based Data Structure, Dipanjan Bhattacharya

Electronic Theses and Dissertations

Developing concurrent algorithms requires safety and liveness to be defined in order to understand their proper behavior. Safety refers to the correctness criteria while liveness is the progress guarantee. Nowadays there are a variety of correctness conditions for concurrent objects. The way these correctness conditions differ and the various trade-offs they present with respect to performance, usability, and progress guarantees is poorly understood. This presents a daunting task for the developers and users of such concurrent algorithms who are trying to better understand the correctness of their code and the various trade-offs associated with their design choices and use. The …

Techniques For Automated Parameter Estimation In Computational Models Of Probabilistic Systems, Faraz Hussain

Electronic Theses and Dissertations

The main contribution of this dissertation is the design of two new algorithms for automatically synthesizing values of numerical parameters of computational models of complex stochastic systems such that the resultant model meets user-specified behavioral specifications. These algorithms are designed to operate on probabilistic systems – systems that, in general, behave differently under identical conditions. The algorithms work using an approach that combines formal verification and mathematical optimization to explore a model's parameter space. The problem of determining whether a model instantiated with a given set of parameter values satisfies the desired specification is first defined using formal verification terminology, …

Gesture Assessment Of Teachers In An Immersive Rehearsal Environment, Roghayeh Barmaki

Electronic Theses and Dissertations

Interactive training environments typically include feedback mechanisms designed to help trainees improve their performance through either guided- or self-reflection. When the training system deals with human-to-human communications, as one would find in a teacher, counselor, enterprise culture or cross-cultural trainer, such feedback needs to focus on all aspects of human communication. This means that, in addition to verbal communication, nonverbal messages must be captured and analyzed for semantic meaning. The goal of this dissertation is to employ machine-learning algorithms that semi-automate and, where supported, automate event tagging in training systems developed to improve human-to-human interaction. The specific context in which …

Quantitative Framework For Social Cultural Interactions, Taranjeet Singh Bhatia

Electronic Theses and Dissertations

For an autonomous robot or software agent to participate in the social life of humans, it must have a way to perform a calculus of social behavior. Such a calculus must have explanatory power (it must provide a coherent theory for why the humans act the way they do), and predictive power (it must provide some plausible events from the predicted future actions of the humans). This dissertation describes a series of contributions that would allow agents observing or interacting with humans to perform a calculus of social behavior taking into account cultural conventions and socially acceptable behavior models. We …

High-Performance Composable Transactional Data Structures, Deli Zhang

Electronic Theses and Dissertations

Exploiting the parallelism in multiprocessor systems is a major challenge in the post ``power wall'' era. Programming for multicore demands a change in the way we design and use fundamental data structures. Concurrent data structures allow scalable and thread-safe accesses to shared data. They provide operations that appear to take effect atomically when invoked individually. A main obstacle to the practical use of concurrent data structures is their inability to support composable operations, i.e., to execute multiple operations atomically in a transactional manner. The problem stems from the inability of concurrent data structure to ensure atomicity of transactions composed from …

Best Approximations, Lethargy Theorems And Smoothness, Caleb Case

CMC Senior Theses

In this paper we consider sequences of best approximation. We first examine the rho best approximation function and its applications, through an example in approximation theory and two new examples in calculating n-widths. We then further discuss approximation theory by examining a modern proof of Weierstrass's Theorem using Dirac sequences, and providing a new proof of Chebyshev's Equioscillation Theorem, inspired by the de La Vallee Poussin Theorem. Finally, we examine the limits of approximation theorem by looking at Bernstein Lethargy theorem, and a modern generalization to infinite-dimensional subspaces. We all note that smooth functions are bounded by Jackson's Inequalities, but …

Bikei Cohomology And Counting Invariants, Jake L. Rosenfield

CMC Senior Theses

This paper gives a brief introduction into the fundaments of knot theory: introducing knot diagrams, knot invariants, and two techniques to determine whether or not two knots are ambient isotopic. After discussing the basics of knot theory an algebraic coloring of knots knows as a bikei is introduced. The algebraic structure as well as the various axioms that define a bikei are defined. Furthermore, an extension between the Alexander polynomial of a knot and the Alexander Bikei is made. The remainder of the paper is devoted to reintroducing a modified homology and cohomology theory for involutory biquandles known as bikei, …

Topic Analysis Of Tweets On The European Refugee Crisis Using Non-Negative Matrix Factorization, Chong Shen

CMC Senior Theses

The ongoing European Refugee Crisis has been one of the most popular trending topics on Twitter for the past 8 months. This paper applies topic modeling on bulks of tweets to discover the hidden patterns within these social media discussions. In particular, we perform topic analysis through solving Non-negative Matrix Factorization (NMF) as an Inexact Alternating Least Squares problem. We accelerate the computation using techniques including tweet sampling and augmented NMF, compare NMF results with different ranks and visualize the outputs through topic representation and frequency plots. We observe that supportive sentiments maintained a strong presence while negative sentiments such …

Hybrid Integrated Photonic Platforms And Devices, Jeffrey Chiles

Electronic Theses and Dissertations

Integrated photonics has the potential to revolutionize optical systems by achieving drastic reductions in their size, weight and power. Remote spectroscopy, free-space communications and high-speed telecommunications are critical applications that would benefit directly from these advancements. However, many such applications require extremely wide spectral bandwidths, leading to significant challenges in their integration. The choice of integrated platform influences the optical transparency and functionality which can be ultimately achieved. In this work, several new platforms and technologies have been developed to meet these needs. First, the silicon-on-lithium-niobate (SiLN) platform is discussed, on which the first compact, integrated electro-optic modulator in the …

A Ten-Year Comparison Of Women Authorship In U.S. Dermatology Literature, 1999 Vs. 2009, Shali Zhang, Ha-Young Kim, Rachel E.S. Hill, Emir Veledar, Suephy C. Chen

Department of Biostatistics Faculty Publications

Women are entering medicine at increasing rates, particularly in dermatology. In this study, we compared women’s influence and status in academic dermatology with that of men by examining authorship roles in peer-reviewed dermatology literature.Weexamined the literature in2009 and compared that to10 years prior (1999).Atotal of 1399 articles were reviewed, 594 of whichmet study criteria andwere included in statistical analysis. There was amarked increase in senior female authorship over a decade (22% vs. 38%, p b 0.001). Female first authorship increased as well (41% vs. 51%, p b 0.001). In contrast, changes in male senior and first authorship were not statistically …

Hydrogen-Atom Attack On Phenol And Toluene Is Ortho-Directed, Olha Krechkivska, Callan M. Wilcox, Tyler P. Troy, Klaas Nauta, Bun Chan, Rebecca Jacob, Scott A. Reid, Leo Radom, Timothy W. Schmidt, Scott H. Kable

Chemistry Faculty Research and Publications

The reaction of H + phenol and H/D + toluene has been studied in a supersonic expansion after electric discharge. The (1 + 1′) resonance-enhanced multiphoton ionization (REMPI) spectra of the reaction products, at m/z = parent + 1, or parent + 2 amu, were measured by scanning the first (resonance) laser. The resulting spectra are highly structured. Ionization energies were measured by scanning the second (ionization) laser, while the first laser was tuned to a specific transition. Theoretical calculations, benchmarked to the well-studied H + benzene → cyclohexadienyl radical reaction, were performed. The spectrum arising from the …

On Stabilization Of Scattering Resonances In Recombination Reaction That Forms Ozone, Mikhail V. Ivanov, Dmitri Babikov

Chemistry Faculty Research and Publications

Calculations of energy transfer in the recombination reaction that forms ozone are carried out within the framework of the mixed quantum/classical theory and using the dimensionally reduced 2D-model of ozone molecule, with bending motion neglected. Recombination rate coefficients are obtained at room temperature for symmetric and asymmetric isotopomers of singly and doubly substituted isotopologues. The processes of resonance formation, spontaneous decay, collisional dissociation, and stabilization by bath gas (Ar) are all characterized and taken into account within the steady-state approximation for kinetics. The focus is on stabilization step, where the mysterious isotopic η-effect was thought to originate from. Our results …

A Full-Dimensional Model Of Ozone Forming Reaction: The Absolute Value Of The Recombination Rate Coefficient, Its Pressure And Temperature Dependencies, Alexander Teplukhin, Dmitri Babikov

Chemistry Faculty Research and Publications

Rigorous calculations of scattering resonances in ozone are carried out for a broad range of rotational excitations. The accurate potential energy surface of Dawes is adopted, and a new efficient method for calculations of ro–vibrational energies, wave functions and resonance lifetimes is employed (which uses hyper-spherical coordinates, the sequential diagonalization/truncation approach, grid optimization and complex absorbing potential). A detailed analysis is carried out to characterize distributions of resonance energies and lifetimes, their rotational/vibrational content and their positions with respect to the centrifugal barrier. Emphasis is on the contribution of these resonances to the recombination process that forms ozone. It is …

From Wires To Cables: Attempted Synthesis Of 1,3,5-Trifluorenylcyclohexane As A Platform For Molecular Cables, Marat R. Talipov, Sameh H. Abdelwahed, Khushabu Thakur, Scott Reid, Rajendra Rathore

Chemistry Faculty Research and Publications

Multiple molecular wires braided together in a single assembly, termed as molecular cable, are promising next-generation materials for effective long-range charge transport. As an example of the platform for constructing molecular cables, 1,3,5-trifluorenylcyclohexane (TFC) and its difluorenyl analogues (DFCs) were systematically investigated both experimentally (X-ray crystallography) and theoretically (DFT calculations). Although the syntheses of DFCs were successfully achieved, the synthesis of TFC, which involved a similar intramolecular Friedel–Crafts cyclization as the last step, was unsuccessful. An exhaustive study of the conformational landscape of cyclohexane ring of TFC and DFCs revealed that TFC is …

The Periodical Winter 2016, Southern Adventist University

the Periodical – Chemistry Department Newsletter

Volume 3, issue 2 of the Periodical includes articles about the Chemistry Club's community service, a pictorial listing of May 2016 graduates, student Jeron Estwick's presentation at a chemistry conference, a feature on students recognized for academic achievement, and an alumni spotlight.

From Model Systems To Real Catalysts: Bridging The Pressure And Materials Gaps, Audrey S. Duke

Theses and Dissertations

For decades a fundamental understanding of heterogeneous catalysts has been pursued for rational catalyst design using model systems under ultrahigh vacuum (UHV) conditions; however, there exist stark differences between the simplified models investigated under UHV and the industrial catalysts used at high pressures. To bridge these gaps, it becomes essential to utilize progressively more complex materials and to correlate their surface structure and activity using incrementally higher pressure techniques. In this work, both model Pt-Re catalysts and powdered metal-organic frameworks (MOFs) were studied using a suite of traditional UHV surface science techniques in addition to ambient pressure X-ray photoelectron spectroscopy …

Materials Discovery By Crystal Growth: Synthesis, Structure Determination, Magnetic, And Optical Properties Of Complex Lanthanide Containing Oxides, Oxyhydroxides, And Oxyfluorides, Allison Marie Latshaw

Theses and Dissertations

Exploratory crystal growth is a versatile technique and one that can advance materials discovery. Through exploratory crystal growth, it is possible to synthesize many new materials that can have applications in many fields, including solid-state lighting. There exist many adaptations for exploratory crystal growth, including the use of alkali halide flux growth and hydroflux growth, both reported herein. By changing variants in these techniques like reactant ratios, temperature, reaction profile, and, most importantly here, the flux compositions, it is possible to change the products formed or fine tune reactions for product purity.

For solid-state lighting applications, compounds that adopt colorless …

On Crown-Free Set Families, Diffusion State Difference, And Non-Uniform Hypergraphs, Edward Lawrence Boehnlein

Theses and Dissertations

We present results in three different arenas of discrete mathematics. Let La(n, H) denote the cardinality of the largest family on the Boolean lattice that does not contain H as a subposet. Denote π(H) := limn→∞ La(n,H) (bn/ n2c) . A crown O2k for k ≥ 2 is a poset on 2 levels whose Hasse diagram is a cycle. Griggs and Lu (2009) showed π(O4k) = 1 for k ≥ 2. Lu (2014) proved π(O2k) = 1 for odd k ≥ 7. We prove that the maximum size of a O6 -free family, when restricted to the middle two levels …

Binary Quartic Forms Over Fp, Daniel Thomas Kamenetsky

Theses and Dissertations

Let Vp denote the five dimensional vector space of binary quartic forms over the finite field Fp, with p a prime greater than 3. There is a natural action of the group GL1(Fp)×GL2(Fp) on Vp. This action partitions Vp into orbits, the number of which increases with p. In this thesis, we determine explicitly, for a given p, the number of orbits under the action of GL1(Fp) × GL2(Fp) on Vp. Moreover, we determine the size of each orbit and the general structure of the forms each orbit contains. We also introduce an application of understanding these orbits to the …

High Flow Events As Hot Moments Of Reactive Fe And P Export: Impacts Of Land Cover And Seasonality, Braden Rosenberg

Graduate College Dissertations and Theses

High flow events often comprise the majority of annual discharge and riverine geochemical flux of phosphorus (P) and metals such as iron (Fe) and manganese (Mn) due to glacial melt, snowmelt, and storm-driven sustained high flow. Aquatic ecosystem productivity in receiving water bodies such as Lake Champlain and the Gulf of Alaska (GoA) are impacted by the riverine import of nutrients. The magnitude of these high flow events can be a strong predictor of receiving water body conditions, and in some cases can contribute to eutrophication. We explore the intersection of high flow events and land cover in contrasting catchments …

Hom-Lie 2-Superalgebras, Chunyue Wang, Qingcheng Zhang, Jizhu Nan

Turkish Journal of Mathematics

Hom-Lie 2-superalgebras can be considered as the categorification of Hom-Lie superalgebras. We give the definition of Hom-Lie 2-superalgebras and study their superderivations. We obtain the representation, deformation, and abelian extensions related to the 2-cocycle and Hom-Nijenhuis operators. Moreover, we also construct a skeletal (strict) Hom-Lie 2-superalgebra from a Hom-associative Rota--Baxter superalgebra.

The $Q$-Analogue Of The $E_{2;1}$-Transform And Its Applications, Ahmed Salem, Faruk Uçar

Turkish Journal of Mathematics

In this paper, we introduce a new integral transform $\ _{q}\mathcal{E}_{2;1}$, which is the $q$-analogue of the $\mathcal{E}_{2;1}$-transform and can be regarded as a $\mathit{q}$-extension of the $\mathcal{E}_{2;1}$-transform. Some identities involving $~_{q}L_{2}$-transfom, $~_{q}\mathcal{L}_{2}$-transfom, and $\mathcal{P}_{q}$-transform are given. By making use of these identities and $\ _{q}\mathcal{E}_{2;1}$-transform, a new Parseval--Goldstein type theorem is obtained. Some examples are also given as an illustration of the main results presented here.

A Note On Riesz Space Valued Measures, Neşet Özkan Tan

Turkish Journal of Mathematics

In this paper, some properties of Riesz space valued measures that are defined on an algebra of sets are obtained. The question of under what conditions $oba(\mathcal{F},E)$ =$a(\mathcal{F},E)$ for a given Dedekind complete Riesz space $E$ is answered under natural conditions. The outer measure, which is generated by order bounded Riesz space valued measure, is obtained and its properties are investigated. The concept of hazy convergence that is valid for real valued signed measures is extended to Riesz space valued measures. The consequences of order convergence of $f:X\rightarrow E$, which implies hazy convergence, are given.

Shellability Of Simplicial Complexes And Simplicial Complexes With The Free Vertex Property, Guangjun Zhu

Turkish Journal of Mathematics

To a simplicial complex $\Delta$, we associate a square-free monomial ideal $\mathcal{F}(\Delta)$ in the polynomial ring generated by its facet over a field. Furthermore, we could consider $\mathcal{F}(\Delta)$ as the Stanley--Reisner ideal of another simplicial complex $\delta_{N}(\mathcal{F}(\Delta))$ from facet ideal theory and Stanley--Reisner theory. In this paper, we determine what families of simplicial complexes $\Delta$ have the property that their Stanley--Reisner complexes $\delta_{N}(\mathcal{F}(\Delta))$ are shellable. Furthermore, we show that the simplicial complex with the free vertex property is sequentially Cohen--Macaulay. This result gives a new proof for a result of Faridi on the sequentially Cohen--Macaulayness of simplicial forests.

On The Finite $P$-Groups With Unique Cyclic Subgroup Of Given Order, Libo Zhao, Yangming Li, Lu Gong

Turkish Journal of Mathematics

In this paper, we prove that if $G$ is nonabelian and $ G >p^4$, then $G$ has a unique cyclic subgroup of order $p^m$ with $m\geq 3$ if and only if $G$ has a unique abelian subgroup of order $p^3$ if and only if $G$ is a $2$-group of maximal class.

Sparse Sums With Bases Of Chebyshev Polynomials Of The Third And Fourth Kind, Maryam Shams Solary

Turkish Journal of Mathematics

We derive a generalization for the reconstruction of $M$-sparse sums in Chebyshev bases of the third and fourth kind. This work is used for a polynomial with Chebyshev sparsity and samples on a Chebyshev grid of $[-1,1]$. Further, fundamental reconstruction algorithms can be a way for getting M-sparse expansions of Chebyshev polynomials of the third and fourth kind. The numerical results for these algorithms are designed to compare the time effects of doing them.

Stability And Data Dependence Results For The Jungck--Khan Iterative Scheme, Abdul Rahim Khan, Fai̇k Gürsoy, Vivek Kumar

Turkish Journal of Mathematics

The Jungck--Khan iterative scheme for a pair of nonself operators contains as a special case Jungck--Ishikawa and Jungck--Mann iterative schemes. In this paper, we establish improved results about convergence, stability, and data dependence for the Jungck--Khan iterative scheme.

On Congruences Related To Central Binomial Coefficients, Harmonic And Lucasnumbers, Si̇bel Koparal, Neşe Ömür

Turkish Journal of Mathematics

In this paper, using some combinatorial identities, we present new congruences involving central binomial coefficients and harmonic, Catalan, and Fibonacci numbers. For example, for an odd prime $p$, we have \begin{eqnarray*} \sum\limits_{k=1}^{\left( p-1\right) /2}\left( -1\right) ^{k}\binom{2k}{k}% H_{k-1} &\equiv &\frac{2^{p}}{p}\left( 2F_{p+1}-5^{\left( p-1\right) /2}-1\right) ({\rm mod\ }p), \\ \sum\limits_{k=0}^{\left( p-1\right) /2}\frac{H_{k}C_{k}}{\left( -4\right) ^{k}} &\equiv &2\frac{Q_{p+1}}{p}-\frac{2^{p+1}}{p}\left( 1+2^{\left( p+1\right) /2}\right) ({\rm mod\ }p), \end{eqnarray*}% and for $\left( \frac{5}{p}\right) =1,$% \begin{equation*} \sum\limits_{k=1}^{\left( p-1\right) /2}\binom{2k}{k}\frac{H_{k-1}F_{k}}{% \left( -4\right) ^{k}}\equiv \frac{1}{p}\left( F_{2p+1}-F_{p+2}\right) -% \frac{2^{p}}{p}F_{p-1}({\rm mod\ }p), \end{equation*} where $\left\{ F_{n}\right\} $ is the Fibonacci sequence and $\left\{ Q_{n}\right\} $ is the Pell-Lucas sequence.

Some Upper Bounds On The Dimension Of The Schur Multiplierof A Pair Of Nilpotent Lie Algebras, Behrouz Edalatzadeh

Turkish Journal of Mathematics

Let $(L,N)$ be a pair of Lie algebras where $N$ is an ideal of the finite dimensional nilpotent Lie algebra $L$. Some upper bounds on the dimension of the Schur multiplier of $(L,N)$ are obtained without considering the existence of a complement for $N$. These results are applied to derive a new bound on the dimension of the Schur multiplier of a nilpotent Lie algebra.