Physical Sciences and Mathematics Commons^™

Categorical And Fuzzy Ensemble-Based Algorithms For Cluster Analysis, Bridget Nicole Manning

Theses and Dissertations

This dissertation focuses on improving multivariate methods of cluster analysis. In Chapter 3 we discuss methods relevant to the categorical clustering of tertiary data while Chapter 4 considers the clustering of quantitative data using ensemble algorithms. Lastly, in Chapter 5, future research plans are discussed to investigate the clustering of spatial binary data.

Cluster analysis is an unsupervised methodology whose results may be influenced by the types of variables recorded on observations. When dealing with the clustering of categorical data, solutions produced may not accurately reflect the structure of the process that generated them. Increased variability within the latent structure …

Incorporation And Measurement Of Uncertainty In Clustered And Spatial Data, Yuan Hong

Theses and Dissertations

Analyzing population representative datasets for local estimation and predictions over time is important for monitoring related public health issues, however, there are many statistical challenges associated with such analyses. Mixed effect models are one of the common options which can incorporate time and spatial effect in the model and related inference is well established.

In the first part of this dissertation, to estimate area-level prevalence using individuallevel data, small area estimation (SAE) with post-stratified mixed effect models were used where sampling weights were also incorporated into it. However, if poststratification which requires more computation effort can improve estimation accuracy is …

Fermi-Unsmearing In Single Charged Pion Electroproduction Cross-Section Measurements For The Neutron And Proton In Deuterium, Gary Hollis

Theses and Dissertations

Electron scattering cross-sections for two different reaction channels, e- + p→ e- + n + ϖ + and e- + n → e- + p ϖ - using an unpolarized deuterium target, were extracted from Jefferson Lab experiment E1E data with a beam energy of 2.039 GeV, providing a (W;Q2) coverage of 1.1 GeV < W < 1.9 GeV and0.4 GeV2< Q2 2. Although there has already been an analysis of this same data set for the second reaction channel listed above [1], more of the cross-section domain has been covered in this analysis due to applying a new technique called Fermi-unsmearing. Fermi-smearing is a distortion in a cross-section measurement which occurs whenever the target is erroneously assumed to be at rest but is in fact a bound nucleon as part of a larger nucleus (and thus is in Fermi-motion). Fermi-unsmearing is a Monte Carlo method presented in this work for generating a correction factor that removes the Fermi-smearing effect from an existing cross-section measurement that suffers from Fermi-smearing. Using Fermi-unsmearing can have the advantage of significantly larger statistical sample sizes given the same data set due to allowing less strict final data selection criteria, as occurs in a Fermi-unsmeared analysis of the e- + n→ e- + p + ϖ- channel in contrast to a fully-exclusive analysis of the same channel. The same Fermi-unsmearing method is applied to the first channel after having established the efficacy of the method using the second channel.

Measurements Of Rate Exchange Dynamics In Supercooled Ortho-Terphenyl By Single-Molecule 3d Kinetics And Green’S Functions, Harveen Kaur

Theses and Dissertations

Heterogeneity in relaxation rates is a well-established feature of supercooled liquids. It implies the existence of a rate-exchange process to restore ergodicity, but the experimental characterization of that exchange has been incomplete and controversial. This dissertation develops three-dimensional (3D) correlation functions that provide a well-defined measure of rate exchange from single-molecule measurements. This approach is demonstrated on both single-molecule dichroism measurements and atomistic simulations of molecular rotation in ortho-terphenyl.

The first project develops non-parametric analysis of nonexponential and multidimensional kinetics. The quantification of nonexponential (dispersed) kinetics has relied on empirical functions, which yield parameters that are neither unique nor easily …

Synthesis And Design Of Novel Polymer Grafted Nanoparticles Relevant To Drug Delivery Vehicles For Biomedical Applications, Maan Abduldiyem Hassan Al-Ali

Theses and Dissertations

The modification of inorganic nanoparticles with organic polymer chains has become a significant field of study for the engineering of advanced nanocomposite materials. This dissertation presents the design, synthesis, and characterization of novel polymer grafted silica nanoparticles as new strategies to combat bacterial resistance. Described herein is the synthesis of monomers that have been graft polymerized onto silica nanoparticles that can be used as a delivery drug vehicle for biomedical applications. The polymerization of these monomers was performed via reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular design of the RAFT agents that are attached to the surfaces of the …

Estimation And Inference Under Model Uncertainty, Yizheng Wei

Theses and Dissertations

Chapter 1 of this dissertation proposes a consistent and locally efficient estimator to estimate the model parameters for a logistic mixed effect model with random slopes. Our approach relaxes two typical assumptions: the random effects being normally distributed, and the covariates and random effects being independent of each other. Adhering to these assumptions is particularly difficult in health studies where in many cases we have limited resources to design experiments and gather data in long-term studies, while new findings from other fields might emerge, suggesting the violation of such assumptions. So it is crucial if we could have an estimator …

Providing Predictable Performance During Network Contingencies, Phani Krishna Penumarthi

Theses and Dissertations

In IP backbone networks, packets may get dropped due to: i) lack of viable next hops when a link/router fails, ii) forwarding loops during network convergence, and iii) buffer overflows in case of congestion. Similarly, packets may be lost in wireless networks due to variations in signal strength between a pair of mobile nodes. This dissertation explores the possibility of providing a predictable performance during such network contingencies in wired backbone networks and robotic wireless networks.

First, we study the feasibility of developing a combination of local reroute and global update mechanisms that can achieve loop-free convergence, while performing disruption-free …

The Utility Of Multiple Structure Torsion Angle Alignment In Protein Active Site Description (Asd), Devaun L. Mcfarland

Theses and Dissertations

Proteins are responsible for various functions throughout organisms, or within the systems, they operate. Active-sites or functional/ binding sites are regions responsible for activity in a protein; they serve as a catalyst for reactions, attach or bind to other molecules (ligands), and maintain function. With the profusion of protein sequence and structure data, it's increasingly relevant to develop automated methods of identifying and investigating active-sites for proteins. Active-sites identification will have a direct impact: in better understanding molecular basis for diseases, assisting in drug design, the study of targeting mutants, and for functional annotation of unknown proteins. The proper knowledge …

A Novel Analytical Method For Studying Pharmacological Treatments For Affective Disorders In Neuroscience, Shane N. Berger

Theses and Dissertations

Histamine and serotonin are important neurochemicals that maintain crucial brain functions. Both are thought to be altered in affective and neurodegenerative disorders such as depression and Parkinson’s disease. Histamine and serotonin are thought to modulate one another but the exact relationship remains unknown and this gap in knowledge makes diagnosing and treating disorders involving the transmitters difficult. The Hashemi lab studies serotonin neurochemistry to understand serotonin’s role in psychiatric disorders. However, histamine has remained an understudied neurotransmitter due to a lack of analytical tools. In 2015 and 2016, the Hashemi lab pioneered a novel detection method utilizing fast-scan cyclic voltammetry …

Variable-Order Fractional Partial Differential Equations: Analysis, Approximation And Inverse Problem, Xiangcheng Zheng

Theses and Dissertations

Variable-order fractional partial differential equations provide a competitive means in modeling challenging phenomena such as the anomalous diffusion and the memory effects and thus attract widely attentions. However, variable-order fractional models exhibit salient features compared with their constant-order counterparts and introduce mathematical and numerical difficulties that are not common in the context of integer-order and constant-order fractional partial differential equations.

This dissertation intends to carry out a comprehensive investigation on the mathematical analysis and numerical approximations to variable-order fractional derivative problems, including variable-order time-fractional, space-fractional, and space-time fractional partial differential equations, as well as the corresponding inverse problems. Novel techniques …

Algorithmic Robot Design: Label Maps, Procrustean Graphs, And The Boundary Of Non-Destructiveness, Shervin Ghasemlou

Theses and Dissertations

This dissertation is focused on the problem of algorithmic robot design. The process of designing a robot or a team of robots that can reliably accomplish a task in an environment requires several key elements. How the problem is formulated can play a big role in the design process. The ability of the model to correctly reflect the environment, the events, and different pieces of the problem is crucial. Another key element is the ability of the model to show the relationship between different designs of a single system. These two elements can enable design algorithms to navigate through the …

High-Dimensional Inference Based On The Leave-One-Covariate-Out Regularization Path, Xiangyang Cao

Theses and Dissertations

The increasingly rapid emergence of high dimensional data, where the number of variables p may be larger than the sample size n, has necessitated the development of new statistical methodologies. LASSO and variants of LASSO are proposed and have been the most popular estimators for the high dimensional regression models. However, not much work has focused on analyzing and summarizing the information contained in the entire solution path of the LASSO. This dissertation consists of three research projects that propose and extend the Leave-One-Covariate-Out(LOCO) solution path statistic to regression and graphical models.

In the first chapter, we propose a new …

Methods For Cancellation Of Apparent Cerenkov Radiation Arising From Sme Models And Separability Of Schrödinger’S Equation Using Exotic Potentials In Parabolic Coordinates, Richard Henry Decosta

Theses and Dissertations

In an attempt to merge the two prominent areas of physics: The Standard Model and General Relativity, there have been many theories for the underlying physics that may lead to Lorentz- and CPT-symmetry violations. At the present moment, technology allows numerous types of Planck-sensitive tests of these symmetries in a range of physical systems.

We address a curiosity in isotropic CPT- and Lorentz-violating electrodynamics where there is a kinematic allowance for Cerenkov radiation of a charged particle in a vacuum moving with uniform motion. This however, should not be the case as it is known that constant motion in a …

The Practical Advantages And Disadvantages Of Laplace Regression As An Alternative To Cox Proportional Hazards Model: A Comparison Via Simulation, Sydney Smith

Theses and Dissertations

The Cox proportional hazards model is the most common regression technique for survival analysis. However, the proportional hazards assumption restricts it’s use to a limited group of multiplicative models. Laplace regression is a flexible quantile regression technique for censored observations that is appropriate in a wider variety of applications as compared to the Cox proportional hazards model. Instead of estimating a hazard ratio, Laplace regression which is free from a proportionality assumption, can be used to estimate many adjusted percentiles of survival time allowing for a more complete description of the association of interest. This paper compares the performance of …

Exploratory Molten Flux Crystal Growth Of Complex Uranium Oxides, Christian A. Juillerat

Theses and Dissertations

While the use of nuclear technology has proven useful for energy generation and for military use, the proper disposal and storage of the resulting nuclear waste requires serious attention to ensure radioactive species are indefinitely sequestered to protect the biosphere. There are several classifications of nuclear waste such as spent nuclear fuel (from industrial power plants), low level waste (slightly contaminated trash), and high level waste (HLW) which is in the form of a sludge, precipitated salt, or liquid. Each of these requires a different approach to processing and storage. Of these, HLW requires the most attention because it is …

Semiparametric Regression Analysis Of Survival Data And Panel Count Data, Lu Wang

Theses and Dissertations

Both censored survival data and panel count data arise commonly in real-life studies in many fields such as epidemiology, social science, and medical research. In these studies, subjects are usually examined multiple times at periodical or irregular follow-up examinations. Censored data are studied when the exact failure times of the events are of interest but not all of these exact times are directly observed. Some of the failure times of event of interest are only known to fall within some intervals formed by the observation times. Panel count data are under investigation when the exact times of the recurrent events …

Disinfection Byproduct Drivers Of Cytotoxicity In Drinking Water And Swimming Pools, Joshua M. Allen

Theses and Dissertations

Water disinfection was cited as the greatest public health achievement of the 20th Century. By inactivating pathogens, disinfection has significantly reduced waterborne diseases in drinking water and swimming pools. However, chemical disinfection has also raised a public health issue: the potential for cancer induction, reproductive and developmental effects, and asthma-related risks associated with exposure to chemical disinfection byproducts (DBPs), which are formed by the reaction of disinfectants with organic matter (natural or anthropogenic), bromide, and iodide. In the U.S., four trihalomethanes (THMs) and five haloacetic acids (HAAs) are currently regulated in drinking water, although no DBPs are regulated in pools, …

Bayesian Zero-Inflated Model For Ordinal Data, Huizhong Yang

Theses and Dissertations

Datasets with a relatively large number of zeros is commonly seen in medical applications. Although models like Zero-inflated Poisson (ZIP) model are proposed for counts data, there is still some issues with ordinal data which have excess zeros. In this paper, we developed a Bayesian approach to accommodate the excess zero in ordinal data. Intellectual disability (ID), also known as mental retardation (MR), is a disability characterized by below-average intelligence or mental ability and a lack of the learning necessary skills for daily life. A person with intellectual disability has intellectual functioning and adaptive behaviors limitations. Intellectual disability is a …

Cosmic Metal Evolution During The First ∼1 Billion Years After The Big Bang Using Damped/Sub-Damped Lyman-Alpha Absorbers, Suraj Poudel

Theses and Dissertations

Metal abundance measurements throughout the cosmic ages track the history of galaxy formation and evolution. Measuring abundances during the first ∼1 billion years is especially important, as they are influenced by the nucleosynthetic signatures from the early stars. Evolution of metallicity of Damped/sub-Damped Lyman-alpha Absorbers (DLAs/sub-DLAs) detected in the spectra of quasars is a powerful tracer of the cosmic star formation history. A sudden drop in DLA metallicity at z>4.7 was reported in some recent studies. However, these studies were primarily based on refractory elements such as Fe and Si. We present ten new abundance measurements of the elements …

Network-Based Statistical Analysis Of Functional Magnetic Resonance Imaging Data From Aphasia Patients, Xingpei Zhao

Theses and Dissertations

Functional magnetic resonance imaging (fMRI) is a neuroimaging technique that provides insight into brain function and activity. Network models of fMRI signals can reveal functional connectivity related to certain brain disorders, such as post-stroke aphasia. This thesis aims to identify the functional connections that distinguish anomic and Broca’s aphasia by comparing the resting-state fMRI from the patients with these two types of aphasia. The network-based statistic (NBS) approach is used to detect such connections. After the analytic pipeline is applied to the fMRI data, the NBS approach identifies a distinct subnetwork between the two types of aphasia, which involves the …

Moving-Camera Video Content Analysis Via Action Recognition And Homography Transformation, Yang Mi

Theses and Dissertations

Moving-camera video content analysis aims at interpreting useful information in videos taken by moving cameras, including wearable cameras and handy cameras. It is an essential problem in computer vision, and plays an important role in many real-life applications, including understanding social difficulties and enhancing public security. In this work, we study three sub-problems of moving-camera video content analysis, including two sub-problems for the analysis on wearable-camera videos which are a special type of moving camera videos: recognizing general actions and recognizing microactions in wearable-camera videos. And, the third sub-problem is estimating homographies along moving-camera videos.

Recognizing general actions in wearable-camera …

Hydrogen Peroxide And Antioxidant Enzymes Moderate Interaction Of The Carbon And Oxygen Cycles At The Redoxcline, Fan Wang

Theses and Dissertations

Hydrogen peroxide is a reduced form of dioxygen produced in natural waters from a manifold of abiotic and biological processes. Hydrogen peroxide is highly redox active and it often serves to initiate the formation of reactive oxygen species in the environment. It typically exists in natural waters at concentrations ranging from as low as ~ 1 nanomolar in “blue water” marine environments to as high as 10 micromolar near actively effluxing sediments. It has the potential to cause significant toxicity in aquatic organisms, which have evolved a collection of antioxidant enzymes including peroxidase, catalase, and superoxide dismutase. Work in this …

Neutrino Induced Coherent-Pion: Precision Measurement In Nomad And Uses In Oscillation Experiments, Bing Guo

Theses and Dissertations

In the era of high precision oscillation measurements, lead by DUNE and Hyper-K, the Near Detector (ND) faces unprecedented challenges and opportunities. Among the various neutrino events in ND, Coherent meson production plays a special role. It is a non-negligible background to the oscillation signal. However the cross-section models for neutrino induced Coherent meson currently being used are old and imprecise. On the other hand, Coherent meson has a simple experimental signature with minimal nuclear effect making it unique among neutrino-nucleon interactions. Furthermore, the cross section for Coherent meson is the same in neutrino and antineutrino modes. It, thus, potentially …

Smart Sensing Enabled Secure And Usable Pairing And Authentication, Xiaopeng Li

Theses and Dissertations

Internet of Things (IoT) technologies have made our lives more convenient and better informed by sensing and monitoring our surroundings. Security applications, such as device pairing and user authentication, are the fundamentals for building a trustworthy smart environment. A secure and convenient pairing approach is critical to IoT enabled applications, as pairing is to establish a secure wireless communication channel for devices. Besides, a smart environment usually has multiple people (e.g., patients and doctors in a hospital), who have physical access to the deployed IoT devices and sensitive dumb objects (e.g., a cabinet storing medical records); but not all of …

Protein Co-Assembly And Its Application In Enzyme Engineering, Libo Zhang

Theses and Dissertations

Enzymes, as highly efficient biocatalysts, have been researched extensively in both academia and industry because of their distinct advantages including high substrate specificity, high regio- and stereoselectivity, environmentally benign process, etc. Though enzyme catalysis has been scaled up for commercial processes in the pharmaceutical, food and beverage and detergent industries, technical barriers associated with enzyme implementation persist, i.e., low catalytic efficiency at non-natural environment, exhausting product separations, high cost of certain enzymes, etc. Moreover, currently most industrial enzymes are used in single-step reactions; however, multistep and multienzyme catalysis with optimal efficiency could greatly expand its potential for synthetic applications to …

An Overlay Architecture For Pattern Matching, Rasha Elham Karakchi

Theses and Dissertations

Deterministic and Non-deterministic Finite Automata (DFA and NFA) comprise the fundamental unit of work for many emerging big data applications, motivating recent efforts to develop Domain-Specific Architectures (DSAs) to exploit fine-grain parallelism available in automata workloads.

This dissertation presents NAPOLY (Non-Deterministic Automata Processor Over- LaY), an overlay architecture and associated software that attempt to maximally exploit on-chip memory parallelism for NFA evaluation. In order to avoid an upper bound in NFA size that commonly affects prior efforts, NAPOLY is optimized for runtime reconfiguration, allowing for full reconfiguration in 10s of microseconds. NAPOLY is also parameterizable, allowing for offline generation of …

Tailored Multifunctional Heterometallic Metal-Organic Frameworks, Otega Anthonia Ejegbavwo

Theses and Dissertations

Metal-organic frameworks (MOFs), which are well-defined and porous extended structures consisting of organic linkers connected to inorganic secondary building units, are a class of materials that have received tremendous attention over the last decade. This geometrically growing interest in MOFs is attributed to their properties of porosity, tunability, modularity, crystallinity, flexibility, and long-term stability, which makes them attractive candidates for various applications. This dissertation focuses on two major studies, the first part encompasses the strategic design, preparation, and extensive studies of actinide containing MOFs (An-MOFs). This work, presented within the first two chapters, demonstrates the effective utilization of MOF modularity …

Diameter Of 3-Colorable Graphs And Some Remarks On The Midrange Crossing Constant, Inne Singgih

Theses and Dissertations

The first part of this dissertation discussing the problem of bounding the diameter of a graph in terms of its order and minimum degree. The initial problem was solved independently by several authors between 1965 − 1989. They proved that for fixed δ ≥ 2 and large n, diam(G) ≤ 3n+ O(1). In 1989, Erdős, Pach, Pollack, and Tuza conjectured that the upper bound on the diameter can be improved if G does not contain a large complete subgraph K_k.

Let r, δ ≥ 2 be fixed integers and let G be a connected graph with n vertices …

Studies Of Group Fused Lasso And Probit Model For Right-Censored Data, Tuan Quoc Do

Theses and Dissertations

This document is composed of three main chapters. In the first chapter, we study the mixture of experts, a powerful machine learning model in which each expert handles a different region of the covariate space. However, it is crucial to choose an appropriate number of experts to avoid overfitting or underfitting. A group fused lasso (GFL) term is added to the model with the goal of making the coefficients of the experts and the gating network closer together. An algorithm to optimize the problem is also developed using block-wise coordinate descent in the dual counterpart. Numerical results on simulated and …

From Cellular To Holistic: Development Of Algorithms To Study Human Health And Diseases, Casey Anne Cole

Theses and Dissertations

The development of theoretical computational methods and their application has become widespread in the world today. In this dissertation, I present my work in the creation of models to detect and describe complex biological and health related problems. The first major part of my work centers around the creation and enhancement of methods to calculate protein structure and dynamics. To this end, substantial enhancement has been made to the software package REDCRAFT to better facilitate its usage in protein structure calculation. The enhancements have led to an overall increase in its ability to characterize proteins under difficult conditions such as …