# Physical Sciences and Mathematics Commons™

Articles 1 - 30 of 1537

## Full-Text Articles in Physical Sciences and Mathematics

Model Misspecification And Assumption Violations With The Linear Mixed Model: A Meta-Analysis, Brandon Lebeau, Yoon Ah Song, Wei Cheng Liu Dec 2018

#### Model Misspecification And Assumption Violations With The Linear Mixed Model: A Meta-Analysis, Brandon Lebeau, Yoon Ah Song, Wei Cheng Liu

##### Department of Psychological and Quantitative Foundations Publications

This meta analysis attempts to synthesize the Monte Carlo literature for the linear mixed model under a longitudinal framework. The empirical type I error rate will serve as the effect size and Monte Carlo simulation conditions will be coded to serve as moderator variables. The type I error rate for the fixed and random effects will be explored as the primary dependent variable. Effect sizes were coded from 13 studies, resulting in a total of 4,002 and 621 effect sizes for fixed and random effects. Meta-regression and proportional odds models were used to explore variation in the empirical type ...

#### Evidence Of A Narrow Structure In ϓ(1s)L⁺L⁻ Mass Spectrum And Cms Phase I And Ii Silicon Detector Upgrade Studies, Suleyman Durgut

##### Theses and Dissertations

This thesis focuses on two parts, the evidence of a structure in a four lepton final state, and the CMS detector upgrade studies.

The first part of the thesis focuses on an unexpected structure in Υ(1S)l+l− final state, where Υ(1S) → μ+μ−, l can represent a muon or an electron and m(l+l−) is required to be below the Υ(1S) mass. Using an integrated luminosity of 25.6 fb−1 recorded in proton-proton collisions at √s = 7 TeV and √s = 8 TeV with the CMS detector at the CERN LHC, an excess in the ...

#### Quinazolin-2-Yl-Guanidines For Treatment Of Neuropsychiatric Disorders And The Oxidative Preparation Of N,O-Acetals Linked To The Amide Bond Of Peptides, Sherif M. S. Ibrahim

##### Theses and Dissertations

This thesis consists of two parts, both on synthetic chemistry with medicinal and biological relevance. Part one aims to develop methods for the preparation of quinazoline derivatives. A streamlined method for the preparation of 6-substituted-4-methyl-2-quinazolyl-guanidines and their respective amides has been presented here, using inexpensive and readily available starting materials such as para-bromoaniline, dicyandiamide (DCDA), and other reagents that are well-established for reactions such as Heck coupling, Suzuki coupling, and Ullman coupling reactions. In part two a novel methodology was developed for the specific incorporation of a masked N,O-acetal at the peptide bond between glycine and other amino ...

Lowest Terms In Commutative Rings, Erik Gregory Hasse Aug 2018

#### Lowest Terms In Commutative Rings, Erik Gregory Hasse

##### Theses and Dissertations

Putting fractions in lowest terms is a common problem for basic algebra courses, but it is rarely discussed in abstract algebra. In a 1990 paper, D.D. Anderson, D.F. Anderson, and M. Zafrullah published a paper called Factorization in Integral Domains, which summarized the results concerning different factorization properties in domains. In it, they defined an LT domain as one where every fraction is equal to a fraction in lowest terms. That is, for any x/y in the field of fractions of D, there is some a/b with x/y=a/b and the greatest common divisor ...

Aug 2018

#### Structural Change Detection Via Penalized Regression, Bo Wang

##### Theses and Dissertations

This dissertation research addresses how to detect structural changes in stochastic linear models. By introducing a special structure to the design matrix, we convert the structural change detection problem to a variable selection problem. There are many existing variable selection strategies, however, they do not fully cope with structural change detection. We design two penalized regression algorithms specifically for the structural change detection purpose. We also propose two methods involving these two algorithms to accomplish a bi-level structural change detection: they locate the change points and also recognize which predictors contribute to the variation of the model structure. Extensive simulation ...

Aug 2018

#### Kinematics And Evolution Of Massive Star Formation In The Central Molecular Zone Of The Galactic Center, Natalie Butterfield

##### Theses and Dissertations

The environmental conditions in the center of the Milky Way galaxy (Central Molecular Zone; CMZ) are much more extreme than in the disk of the galaxy with molecular gas properties similar to those seen in galaxies at z~2. While the CMZ hosts several massive star clusters, the formation of stars from these dense molecular clouds and the feedback of these massive stars on the ISM is not well understood. I present in my thesis a case study of a few regions in the CMZ using VLA continuum and spectral line observations. I explore feedback eects of recent star formation ...

Surface Chemistry Of Metal Oxide Nanoparticles In Biological And Environmental Media Of Varying Ph, Alaa Hani Naser Al Minshid Aug 2018

#### Surface Chemistry Of Metal Oxide Nanoparticles In Biological And Environmental Media Of Varying Ph, Alaa Hani Naser Al Minshid

##### Theses and Dissertations

Investigate the interaction of nanomaterials with biological systems, known as nano-bio interaction is of great interest for the assessment of the concern arising from nanomaterials progressive use. Such interaction determines nanomaterials potential effect on human and environment becomes more and more important to understand how they interact with living organisms and the environment. The novel physicochemical characteristics of nanomaterials, such as their small size, large surface area to volume ratio and surface energy, may initiate new toxicological effects due to nanomaterials ability to enter into the biological systems through adsorption and dissolution and modify the structure of various macromolecules An ...

Invariants Of Hopf Actions On Path Algebras Of Quivers, Ana Berrizbeitia Aug 2018

#### Invariants Of Hopf Actions On Path Algebras Of Quivers, Ana Berrizbeitia

##### Theses and Dissertations

The work of this thesis focuses primarily on non-commutative algebras and actions of Hopf algebras. Specifically, we study the possible H-module algebra structures which can be imposed on path algebras of quivers, for a variety of Hopf algebras, H, and then given a possible action, classify the invariant ring.

A Hopf algebra is a bialgebra (H, μ, η, ∆, ε) together with an antipode S : H → Hop which is compatible with the counit, ε, of H. A quiver is a directed graph, and the path algebra kQ of a quiver Q is a vector space where all the paths of the ...

Persistence Heatmaps For Knotted Data Sets, Catalina Betancourt Aug 2018

#### Persistence Heatmaps For Knotted Data Sets, Catalina Betancourt

##### Theses and Dissertations

Topological Data Analysis is a quickly expanding field but one particular subfield, multidimensional persistence, has hit a dead end. Although TDA is a very active field, it has been proven that the one-dimensional persistence used in persistent homology cannot be generalized to higher dimensions. With this in mind, progress can still be made in the accuracy of approximating it. The central challenge lies in the multiple persistence parameters. Using more than one parameter at a time creates a multi-filtration of the data which cannot be totally ordered in the way that a single filtration can.

The goal of this thesis ...

Aug 2018

#### Online Learning For Imbalanced Data: Optimizing Asymmetric Measures, Xiaoxuan Zhang

##### Theses and Dissertations

Online learning receives increasing attention due to its efficiency in handling large-scale streaming data. However, imbalanced data raises a big challenge for traditional online algorithms which aim at minimizing the misclassification error rate. This thesis works on online learning algorithms that are suitable for classification on imbalanced data.

We first investigate fast converging algorithms directly optimizing asymmetric performance measures, which is challenging because most of the measures are non-decomposable so that standard online optimization methods are not applicable. As a preliminary step, we propose a fast converging adaptive stochastic approxima- tion (ASA) algorithm for the risk minimization with Lipschitz continuous ...

Synthesis Of Carbon Nitrides And Composite Photocatalyst Materials, Anthony Tristan Montoya Aug 2018

#### Synthesis Of Carbon Nitrides And Composite Photocatalyst Materials, Anthony Tristan Montoya

##### Theses and Dissertations

This thesis describes the synthesis, characterization and photocatalytic applications of carbon nitride (C3N4) and titanium dioxide (TiO2) materials. C3N4 was prepared from the thermal decomposition of a trichloromelamine (TCM) precursor. Several different reactor designs and decomposition temperatures were used to produce chemically and thermally stable orange powders. These methods included a low temperature glass Schlenk reactor, a high mass scale stainless steel reactor, and decomposition at higher temperatures by the immersion of a Schlenk tube into a furnace. These products share many of the same structural and chemical properties when produced by these different methods compared to products from more ...

Generalized Additive Runge-Kutta Methods For Stiff Odes, Gregory Mark Tanner Aug 2018

#### Generalized Additive Runge-Kutta Methods For Stiff Odes, Gregory Mark Tanner

##### Theses and Dissertations

In many applications, ordinary differential equations can be additively partitioned

\[y'=f(y)=\sum_{m=1}^{N}\f{}{m}(y).]

It can be advantageous to discriminate between the different parts of the right-hand side according to stiffness, nonlinearity, evaluation cost, etc. In 2015, Sandu and G\"{u}nther \cite{sandu2015gark} introduced Generalized Additive Runge-Kutta (GARK) methods which are given by

\begin{eqnarray*}

Y_{i}^{\{q\}} & = & y_{n}+h\sum_{m=1}^{N}\sum_{j=1}^{s^{\{m\}}}a_{i,j}^{\{q,m\}}f^{\{m\}}\left(Y_{j}^{\{m\}}\right)\\

& & \text{for } i=1,\dots,s^{\{q\}},\,q=1,\dots,N ...

Aug 2018

#### Muon Identification Efficiency Measured With The Cms Detector At √S = 13 Tev, Runxiong Dong

##### Theses and Dissertations

This thesis uses genetic Tag and probe method to study muon ID efficiency in Compact Muon Solenoid(CMS) Detector. CMS is one of the main detectors in Large Hadron Collider, which is the world’s largest and most powerful particle collider. The main object of the CMS Collaboration is to inverstigate physics underlying elec- troweak symmetry breaking. Moreover, the CMS detector allows experimental par- ticle physicists to perform various experiments which possibly produce new physics signatures beyond the Standard Model (SM). In order to detect and study these sig- natures, it requires the identification and accurate and precise measurement of ...

#### Magnetic Field Effect And Other Spectroscopies Of Organic Semiconductor And Hybrid Organic-Inorganic Perovskite Devices, Kevser Sahin Tiras

##### Theses and Dissertations

This thesis consists of three main studies: magnetic field effects in thermally activated delayed fluorescent (TADF) organic light emitting diodes (OLEDs), magnetic field effects in bipolar and unipolar polythiophene (P3HT) devices and a study of hybrid organic/inorganic perovskite devices.

Spin-dependent transport and recombination processes of spin-pair species have been detected by magnetic field effect (MFE) technique in carbon-based semi- conductor devices. Magneto-electroluminescence (MEL) and magneto-conductivity have been measured as a function of the applied magnetic field, B, in light emitting diodes. TADF materials have been used instead of simple fluorescent materials in OLEDs. We have observed very large magnetic ...

Aug 2018

#### Statistical Physics Principles Tested Using Dusty Plasma And Aerosol Experiments, Chun-Shang Wong

##### Theses and Dissertations

Statistical physics has been the foundation for much of our understanding about plasma physics. Often, plasma physics phenomena are explained using statistical physics principles and theories. Here, I reverse this paradigm to instead use plasma experiments to test statistical physics principles.

In this thesis, I test statistical physics principles with an experimental dusty plasma, which is a four-component mixture of micron-sized dust'' particles, electrons, ions, and neutral gas molecules. When immersed in the plasma, the dust particles acquire large negative charges, since they accumulate more electrons than ions. Due to their large electric charges, the dust particles have interparticle potential ...

Factorization In Polynomial Rings With Zero Divisors, Ranthony A.C. Edmonds Aug 2018

#### Factorization In Polynomial Rings With Zero Divisors, Ranthony A.C. Edmonds

##### Theses and Dissertations

Factorization theory is concerned with the decomposition of mathematical objects. Such an object could be a polynomial, a number in the set of integers, or more generally an element in a ring. A classic example of a ring is the set of integers. If we take any two integers, for example 2 and 3, we know that $2 \cdot 3=3\cdot 2$, which shows that multiplication is commutative. Thus, the integers are a commutative ring. Also, if we take any two integers, call them $a$ and $b$, and their product $a\cdot b=0$, we know that $a$ or ...

Aug 2018

#### Development Of Epoxy Nanofiltration Membranes Into Smart Materials For Chemical Separations, Chad Michael Gilmer

##### Theses and Dissertations

Epoxy nanofiltration membranes were synthesized using a diamine and a diepoxide in a one-pot step polymerization. These membranes were stable in organic solvents and used for chemical separations in dichloromethane. The epoxy membranes showed excellent selectivities in chemical separations of over 100:1. The selectivity of the membrane was optimized by adding in a triepoxide to the polymerization to increase the cross-link density. Optimization of the membranes increased the selectivity up to 250:1 for select chemical separations.

These epoxy membranes are some of the first nanofiltration membranes used in the separation of important fatty acids such as omega-3 fish ...

Aug 2018

#### Marginal False Discovery Rate Approaches To Inference On Penalized Regression Models, Ryan Miller

##### Theses and Dissertations

Data containing large number of variables is becoming increasingly more common and sparsity inducing penalized regression methods, such the lasso, have become a popular analysis tool for these datasets due to their ability to naturally perform variable selection. However, quantifying the importance of the variables selected by these models is a difficult task. These difficulties are compounded by the tendency for the most predictive models, for example those which were chosen using procedures like cross-validation, to include substantial amounts of noise variables with no real relationship with the outcome. To address the task of performing inference on penalized regression models ...

Prediction Of Preterm Birth With And Without Preeclampsia Using Mid-Pregnancy Immune And Growth-Related Molecular Factors And Maternal Characteristics, Laura L. Jelliffe-Pawlowski, Larry Rand, Bruce Bedell, Rebecca J. Baer, Scott P. Oltman, Mary E. Norton, Gary M. Shaw, David K. Stevenson, Jeffrey C. Murray, Kelli K. Ryckman Aug 2018

#### Prediction Of Preterm Birth With And Without Preeclampsia Using Mid-Pregnancy Immune And Growth-Related Molecular Factors And Maternal Characteristics, Laura L. Jelliffe-Pawlowski, Larry Rand, Bruce Bedell, Rebecca J. Baer, Scott P. Oltman, Mary E. Norton, Gary M. Shaw, David K. Stevenson, Jeffrey C. Murray, Kelli K. Ryckman

##### Stead Family Department of Pediatrics Publications

OBJECTIVE: To evaluate if mid-pregnancy immune and growth-related molecular factors predict preterm birth (PTB) with and without (±) preeclampsia.

STUDY DESIGN: Included were 400 women with singleton deliveries in California in 2009-2010 (200 PTB and 200 term) divided into training and testing samples at a 2:1 ratio. Sixty-three markers were tested in 15-20 serum samples using multiplex technology. Linear discriminate analysis was used to create a discriminate function. Model performance was assessed using area under the receiver operating characteristic curve (AUC).

RESULTS: Twenty-five serum biomarkers along with maternal age80% of women with PTB ± preeclampsia with best performance in women with ...

Jun 2018

#### Data For A Hybrid Fluxgate And Search Coil Magnetometer Concept Using A Racetrack Core, David M. Miles

##### Research Data

No abstract provided.

May 2018

#### Misspecification Of The Random Effect Structure: Implications For The Linear Mixed Model, Brandon Lebeau

##### Department of Psychological and Quantitative Foundations Publications

The linear mixed model is a commonly used model for longitudinal or nested data due to its ability to account for the dependency of nested data. Researchers typically rely on the random effects to adequately account for the dependency due to correlated data, however serial correlation can also be used. If the random effect structure is misspecified (perhaps due to convergence problems), can the addition of serial correlation overcome this misspecification and allow for unbiased estimation and accurate inferences? This study explored this question with a simulation. Simulation results show that the fixed effects are unbiased, however inflation of the ...

Synthesis Of Carboxyphosphonates And Bisphosphonates As Potential Ggtase Ii And Ggdps Inhibitors, Robert Armin Matthiesen May 2018

#### Synthesis Of Carboxyphosphonates And Bisphosphonates As Potential Ggtase Ii And Ggdps Inhibitors, Robert Armin Matthiesen

##### Theses and Dissertations

Inhibition of enzymes in the isoprenoid biosynthetic pathway (IBP) plays an important role in the treatment of bone diseases and lowering cholesterol. The IBP begins with the enzyme HMG-CoA reductase catalyzing the conversion of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) to mevalonic acid. Mevalonic acid is then converted to isopentenyl pyrophosphate (IPP) via the intermediate mevalonate-5-diphosphate. Three molecules of IPP are joined by the enzyme farnesyl diphosphate synthase (FDPS), which yields the intermediate farnesyl pyrophosphate (FPP). FPP is an important substrate and represents the branch point in the pathway. Compounds which disrupt this pathway at FDPS include risedronate, lovastatin, and zoledronate. It is believed ...

May 2018

#### Probabilistic Pairwise Model Comparisons Based On Discrepancy Measures And A Reconceptualization Of The P-Value, Benjamin N. Riedle

##### Theses and Dissertations

Discrepancy measures are often employed in problems involving the selection and assessment of statistical models. A discrepancy gauges the separation between a fitted candidate model and the underlying generating model. In this work, we consider pairwise comparisons of fitted models based on a probabilistic evaluation of the ordering of the constituent discrepancies. An estimator of the probability is derived using the bootstrap.

In the framework of hypothesis testing, nested models are often compared on the basis of the p-value. Specifically, the simpler null model is favored unless the p-value is sufficiently small, in which case the null model is rejected ...

#### Beyond Asymmetric Allylic Amination: Exploring The Chemistry Of Rhodium-Catalyzed Reactions Of Allylic Trichloroacetimidates In The Synthesis Of Nitrogen And 1,2-Diamine Heterocyclic Compounds, Edward Mwenda

##### Theses and Dissertations

Chiral amines are ubiquitous functionalities found in the architecture of the natural world and have been embedded into materials, catalysts, pharmaceuticals, agrochemicals, and bioactive natural products. However, limited approaches are accessible for the construction of an enantioenriched tertiary or quaternary-containing amine. This thesis describes the development of new methodologies for the synthesis of 7-membered nitrogen-containing heterocycle and 1,2-diamine compounds.

Chapter one describes the application of dynamic kinetic asymmetric amination (DYKAT) of branched allylic acetimidates in the synthesis of 2-alkyldihydrobenzoazepin-5-ones. These 7-membered-ring aza-ketones are generated in good yield with high enantiomeric excess through sequential rhodium-catalyzed allylic amination with 2-amino aryl ...

May 2018

#### On Pricing Barrier Options And Exotic Variations, Xiao Wang

##### Theses and Dissertations

Barrier options have become increasingly popular financial instruments due to the lower costs and the ability to more closely match speculating or hedging needs. In addition, barrier options play a significant role in modeling and managing risks in insurance and finance as well as in refining insurance products such as variable annuities and equity-indexed annuities. Motivated by these immediate applications arising from actuarial and financial contexts, the thesis studies the pricing of barrier options and some exotic variations, assuming that the underlying asset price follows the Black-Scholes model or jump-diffusion processes. Barrier options have already been well treated in the ...

A Study Of Magnetic Fields In Hii Regions Using Faraday Rotation, Allison Hainline Costa May 2018

#### A Study Of Magnetic Fields In Hii Regions Using Faraday Rotation, Allison Hainline Costa

##### Theses and Dissertations

Massive young stars dynamically modify their surroundings, altering their stellar nurseries and the gas that exists between stars. With my research, I assess the modification of the Galactic magnetic field within HII regions and stellar bubbles associated with OB stars. Because HII regions are plasmas, magnetic fields should be important to the dynamics of the region. Understanding how the magnetic field is modified in these structures is critical for inputs to simulations and for assessing stellar feedback. To obtain information on the properties of the magnetic field, I measure the Faraday rotation of linearly polarized radio waves that pass through ...

The Diffeomorphism Field, Delalcan Kilic May 2018

#### The Diffeomorphism Field, Delalcan Kilic

##### Theses and Dissertations

The diffeomorphism field is introduced to the physics literature in [1] where it arises as a background field coupled to Polyakov’s quantum gravity in two dimensions, where Einstein’s gravity is trivial. Moreover, it is seen in many ways as the gravitational analog of the Yang-Mills field. This raises the question of whether the diffeomorphism field exists in higher dimensions, playing an essential role in gravity either by supplementing Einstein’s theory or by modifying it.

With this motivation, several distinct theories governing the dynamics of the diffeomorphism field have been constructed and developed by mimicking the construction of ...

Checkerboard Plumbings, Thomas Kindred May 2018

#### Checkerboard Plumbings, Thomas Kindred

##### Theses and Dissertations

Knots and links $L\subset S^3$ carry a wealth of data. Spanning surfaces $F$ (1- or 2-sided), $\partial F=L$, especially {\bf checkerboard} surfaces from link diagrams $D\subset S^2$, help to mine this data. This text explores the structure of these surfaces, with a focus on a gluing operation called {\bf plumbing}, or {\it Murasugi sum}.

First, naive classification questions provide natural and accessible motivation for the geometric and algebraic notions of essentiality (incompressibility with $\partial$-incompressibility and $\pi_1$-injectivity, respectively). This opening narrative also scaffolds a system of hyperlinks to the usual background information, which lies ...

May 2018

#### Formation Of The Ngandong Paleoanthropological Site And Solo River Terrace Sequence, Central Java, Indonesia, Maija Eliina Sipola

##### Theses and Dissertations

The early human paleoanthropological site at Ngandong, Central Java, Indonesia has significant impact on the models for human migration and evolution out of the African continent. Located on an abandoned stream bank above the Solo River, Ngandong archaeological digs have uncovered fourteen Homo erectus fossils that, based on their unique shape, are believed to have lived more recently than any other known examples of Homo erectus. However, this hypothesis has not been substantiated by previous studies at Ngandong due to a general lack of understanding about the formation of the site as a whole. This study seeks to overcome the ...

May 2018

#### Geochemical Variations In Off-Axis Alkaline Glasses - Snaefellsnes Peninsula, Iceland, Alex Maruszczak

##### Theses and Dissertations

Magmatism on Iceland is dominated by the eruption of tholeiitic lavas along two NE-SW trending rift zones that represent the loci of new crustal formation. Small volumes of transitional to alkaline magmas erupted along the ~120 km long Snæfellsnes Peninsula in western Iceland. The Snæfellsnes Peninsula is broken into three distinct volcanic systems; Ljósufjöll, Lýsuskard, and Snæfellsjökull. This study examines the geochemical compositions and depths of crystallization of alkaline basaltic glass to see if these features vary spatially along the peninsula. Glass MgO values range from 3.4 to 9.0 wt %, TiO2 ranges from 0.9 – 4.8 wt ...