Physical Sciences and Mathematics Commons^™

Adversarial Training For Skill Learning In A Mobile Robot, Todd W. Flyr

Dissertations, Theses, and Capstone Projects

Machine Learning in mobile robotics is sometimes hampered by the difficulties associated with the creation of a large corpus of labeled data that most neural network based learning algorithms demand. In recent years, advances in the field of machine learning have been facilitated via the creation of large collaboratively-created labeled training datasets that researchers can use as the basis for experiments to validate and improve their candidate neural network architectures. For the field of robotics, however, tasks are so disparate and the physical devices so varied that in most cases the creation of collaborative benchmark datasets are impractical. Obtaining data …

Representing The Derivative Of Trace Of Holonomy, Jeffrey Peter Kroll

Dissertations, Theses, and Capstone Projects

Trace of holonomy around a fixed loop defines a function on the space of unitary connections on a hermitian vector bundle over a Riemannian manifold. Using the derivative of trace of holonomy, the loop, and a flat unitary connection, a functional is defined on the vector space of twisted degree 1 cohomology classes with coefficients in skew-hermitian bundle endomorphisms. It is shown that this functional is obtained by pairing elements of cohomology with a degree 1 homology class built directly from the loop and equipped with a flat section obtained from the variation of holonomy around the loop. When the …

Nonlinear Optical Studies Of Interfacial Ferroelectricity And Strain Distribution In Perovskite Dielectric Films, Tony Le

Dissertations, Theses, and Capstone Projects

Dielectric and ferroelectric perovskite films have been model energy storage structures for their low-dielectric loss, extremely high charge-discharge speed, and good temperature stability, yet there is still much to understand about the material’s limitations. This dissertation presents a detailed understanding of the strain-induced ferroelectricity at the boundary between a strontium titanate (SrTiO₃) ultrathin film epitaxially grown on a germanium (Ge) substrate through optical second harmonic generation (SHG), and the polydomain distribution in the Zr-doped BaTiO₃ (BZT) films by time-resolved pump-probe spectroscopy.

First, SHG measurements were performed to reveal interfacial ferroelectricity in the epitaxial SrTiO₃/Ge (100) …

Linear And Non Linear Properties Of Two-Dimensional Exciton-Polaritons, Mandeep Khatoniar

Dissertations, Theses, and Capstone Projects

Technology has been accelerating at breakneck speed since the first quantum revolution, an era that ushered transistors and lasers in the late 1940s and early 1960s. Both of these technologies relied on a matured understanding of quantum theories and since their inception has propelled innovation and development in various sectors like communications, metrology, and sensing. Optical technologies were thought to be the game changers in terms of logic and computing operations, with the elevator pitch being "computing at speed of light", a fundamental speed limit imposed by this universe’s legal system (a.k.a physics). However, it was soon realized that that …

Logics Of Resource And Justification, Hirohiko Kushida

Dissertations, Theses, and Capstone Projects

It is a well-known result by G ̈odel in 1933 that the Intuitionistic Logic can be embedded into a system which is essentially equivalent to the modal logic S4. This can be considered to be an attempt to provide a provability semantics to the Intuitionistic Logic. This work had caused some problems: the exact arithmetical meaning of the Intuitionistic Logic and S4, the exact axiomatization of formal provability in formal arithmetic and the standard model of arithmetic. These days the arithmetical interpretation has been extended and generalized to epistemological interpretation for various modal logics, which resulted in various systems of …

Synthesis, Characterization And Applications Of Europium Based Perovskite Oxide Nanoparticles, Nasim Farahmand

Dissertations, Theses, and Capstone Projects

The synthesis and characterization of nanocrystalline transition and rare-earth metal oxides have been studied widely over the past years. These materials possess unique physical, chemical, magnetic and dielectric properties which make them potential candidates for a wide range of applications such as electronics, energy storage and photocatalysis. There are a number of synthesis methods for preparing these materials, where most of them require stringent conditions such as high pressure and high temperature. However, in this study, a modified sol-gel synthesis has been used with a lower calcination temperature to make uniform nanocrystals of the transition/rare-earth metal oxide family. The focus …

Automated Code Engine For Tensor Hypercontraction: Derivation, Optimization And Implementation Of Rank-Reduced Coupled Cluster Theories, Yao Zhao

Dissertations, Theses, and Capstone Projects

The ultimate goal of electronic structure theory is solving the electronic Schr¨odinger Equation. However, even accurate approximations of solving Schr¨odinger Equation, such as high order coupled cluster theories, require computational efforts that are too demanding to be applied on large chemical systems. This thesis tackles the problem of curse of dimensionality: how to reduce the time complexity of high-accuracy coupled cluster methods in order to accelerate computations of molecular energy. On one hand, we believe that low-rank approximation (i.e. Tensor HyperContraction) of high-order tensors appearing in coupled cluster theory is a promising way to achieve rank-reduced coupled cluster theory. On …

Detecting Stance On Covid-19 Vaccine In A Polarized Media, Rodica Ceslov

Dissertations, Theses, and Capstone Projects

The growing polarization in the United States has been widely reported. Media coverage plays an important role in shaping public opinion and influences public debates on complex and unfamiliar topics. There are some benefits to individuals and society from political polarization and conflict between opposing viewpoints. However, recent research has primarily highlighted the negative consequences of polarization which reached an all-time high. One such topic is the Covid-19 vaccine which was developed in record time, and the public learned about its safety and possible risks through the media coverage.

In this capstone, we examine U.S. news media coverage on the …

Enhanced Platinum (Ii) Drug Delivery For Anti-Cancer Therapy, Marek T. Wlodarczyk

Dissertations, Theses, and Capstone Projects

Over the years, anti-cancer therapies have improved the overall survival rate of patients. Nevertheless, the traditional free drug therapies still suffer from side effects and systemic toxicity, resulting in low drug dosages in the clinic. This often leads to suboptimal drug concentrations reaching cancer cells, contributing to treatment failure and drug resistance. Among available anti-cancer therapies, metallodrugs are of great interest. Platinum (II)-based agents are highly potent and are used to treat many cancers, including ovarian cancer (OC). Cisplatin (cis-diaminedichloroplatinum (II)) is the first Food and Drug Administration (FDA)-approved metallodrug for treatment of solid tumors, and its mechanism …

Clifford Harmonics, Samuel L. Hosmer

Dissertations, Theses, and Capstone Projects

In 1980 Michelsohn defined a differential operator on sections of the complex Clifford bundle over a compact Kähler manifold M. This operator is a differential and its Laplacian agrees with the Laplacian of the Dolbeault operator on forms through a natural identification of differential forms with sections of the Clifford bundle. Relaxing the condition that M be Kähler, we introduce two differential operators on sections of the complex Clifford bundle over a compact almost Hermitian manifold which naturally generalize the one introduced by Michelsohn. We show surprising Kähler- like symmetries of the kernel of the Laplacians of these operators in …

Developing Dynamical Probes Of Quantum Spin Liquids Inspired By Techniques From Spintronics, Joshua Aftergood

Dissertations, Theses, and Capstone Projects

We theoretically study low dimensional insulating spin systems using spin fluctuations as a probe of the spin dynamics. In some systems, low dimensionality in conjunction with other quantum fluctuation enhancing effects impedes spontaneous generation of long range magnetic ordering down to zero absolute temperature. In particular, we focus on exotic spin systems hosting mobile, fractionalized spin excitations above their ground state, and ultimately show that techniques already commonplace in spintronics can be utilized in the context of quantum magnetism to develop probes of exotic ground states.

We initially consider quantum spin chains (QSCs), and examine a system of two exchange-coupled …

Novel Hybrid Resampling Algorithms For Parallel/Distributed Particle Filters, Xudong Zhang

Dissertations, Theses, and Capstone Projects

Particle filters, also known as sequential Monte Carlo (SMC) methods, use the Bayesian inference and the stochastic sampling technique to estimate the states of dynamic systems from given observations. Parallel/Distributed particle filters were introduced to improve the performance of sequential particle filters by using multiple processing units (PUs). The classical resampling algorithm used in parallel/distributed particle filters is a centralized scheme, called centralized resampling, which needs a central unit (CU) to serve as a hub for data transfers. As a result, the centralized resampling procedures produce extra communication costs, which lowers the speedup factors in parallel computing. Even though some …

A Geometric Model For Real And Complex Differential K-Theory, Matthew T. Cushman

Dissertations, Theses, and Capstone Projects

We construct a differential-geometric model for real and complex differential K-theory based on a smooth manifold model for the K-theory spectra defined by Behrens using spaces of Clifford module extensions. After writing representative differential forms for the universal Pontryagin and Chern characters we transgress these forms to all the spaces of the spectra and use them to define an abelian group structure on maps up to an equivalence relation that refines homotopy. Finally we define the differential K-theory functors and verify the axioms of Bunke-Schick for a differential cohomology theory.

Molecular Dynamics Simulations Of Self-Assemblies In Nature And Nanotechnology, Phu Khanh Tang

Dissertations, Theses, and Capstone Projects

Nature usually divides complex systems into smaller building blocks specializing in a few tasks since one entity cannot achieve everything. Therefore, self-assembly is a robust tool exploited by Nature to build hierarchical systems that accomplish unique functions. The cell membrane distinguishes itself as an example of Nature’s self-assembly, defining and protecting the cell. By mimicking Nature’s designs using synthetically designed self-assemblies, researchers with advanced nanotechnological comprehension can manipulate these synthetic self-assemblies to improve many aspects of modern medicine and materials science. Understanding the competing underlying molecular interactions in self-assembly is always of interest to the academic scientific community and industry. …

A Unified Approach To M Dwarf Ages, Rocio Kiman

Dissertations, Theses, and Capstone Projects

Estimating ages of M dwarfs, the lowest mass stars in the Galaxy, is a current unresolved problem in Astrophysics. This dissertation focuses on developing a method to estimate ages for M dwarfs. This method consists of combining different age indicators in a Bayesian framework to achieve a precise age measurement. The age indicators I use are: 1) position in the color-magnitude diagram which is a proxy for effective temperature and luminosity, 2) movement of the stars in the Galaxy, or its 3D kinematics, 3) magnetic activity, measured by the Halpha emission line of the spectrum. In this dissertation I analyze …

Carbon And Nitrogen Dynamics Of A Lagoon Salt Marsh In Davenport, California, Mark D. Gormley

Dissertations, Theses, and Capstone Projects

Wetlands are complex environments that play a critical role in regulating the global biogeochemical cycle of carbon (C) and nitrogen (N). Wetlands are critical contributors to global climate change and atmospheric chemistry since they store as much as 33% of the world’s soil organic carbon (SOC), release more than 20% of the atmospheric methane (CH₄), and produce nitrous oxide (N₂O), an extremely potent greenhouse gas (GHG). Despite the enormous radiative forcing potential of carbon dioxide (CO₂), CH₄ and N₂O derived from wetlands, uncertainties over the rates of C sequestration and GHG …

Evaluation Of The Potential Of Automated Sem-Eds Analysis For The Discrimination Of Inorganic Soil Particles, Anna S. Duggar

Dissertations, Theses, and Capstone Projects

Soil, that complex mixture of minerals, organic particles, chemicals, and anthropogenic materials, is ubiquitous and easily transferred, which gives it forensic relevance. Forensic soil analysis has traditionally included the identification and comparison of both organic and inorganic components, the inorganic portion being most commonly examined by light microscopy and other instrumental techniques. Predominantly, the inorganic materials in soil are naturally-occurring minerals, contributed as grains from the surrounding bedrock, which gives a soil its regional character. That parent material then undergoes physical, chemical, and anthropogenic changes producing wide geographic variation within a single region. This variation forms the basis for potential …

College Algebra Through Problem Solving (2021 Edition), Danielle Cifone, Karan Puri, Debra Maslanko, Ewa Stelmach

Open Educational Resources

This is a self-contained, open educational resource (OER) textbook for college algebra. Students can use the book to learn concepts and work in the book themselves. Instructors can adapt the book for use in any college algebra course to facilitate active learning through problem solving. Additional resources such as classroom assessments and online/printable homework is available from the authors.

Modeling Covid-19 Spread In Small Colleges, Riti Bahl, Nicole Eikmeier, Alexandra Fraser, Matthew Junge, Felicia Keesing, Kukai Nakahata, Lily Reeves

Publications and Research

We develop an agent-based model on a network meant to capture features unique to COVID-19 spread through a small residential college. We find that a safe reopening requires strong policy from administrators combined with cautious behavior from students. Strong policy includes weekly screening tests with quick turnaround and halving the campus population. Cautious behavior from students means wearing facemasks, socializing less, and showing up for COVID-19 testing. We also find that comprehensive testing and facemasks are the most effective single interventions, building closures can lead to infection spikes in other areas depending on student behavior, and faster return of test …

Teaching Machine Learning For The Physical Sciences: A Summary Of Lessons Learned And Challenges, Viviana Acquaviva

Publications and Research

This paper summarizes some challenges encountered and best practices established in several years of teaching Machine Learning for the Physical Sciences at the undergraduate and graduate level. I discuss motivations for teaching ML to physicists, desirable properties of pedagogical materials, such as accessibility, relevance, and likeness to real-world research problems, and give examples of components of teaching units.

An Adaptive Cryptosystem On A Finite Field, Awnon Bhowmik, Unnikrishnan Menon

Publications and Research

Owing to mathematical theory and computational power evolution, modern cryptosystems demand ingenious trapdoor functions as their foundation to extend the gap between an enthusiastic interceptor and sensitive information. This paper introduces an adaptive block encryption scheme. This system is based on product, exponent, and modulo operation on a finite field. At the heart of this algorithm lies an innovative and robust trapdoor function that operates in the Galois Field and is responsible for the superior speed and security offered by it. Prime number theorem plays a fundamental role in this system, to keep unwelcome adversaries at bay. This is a …

Case 3847 – Simopithecus Oswaldi Andrews, 1916 (Currently Theropithecus Oswaldi; Mammalia, Primates, Cercopithecidae), Proposed Conservation By Reversal Of Precedence With Cynocephalus Atlanticus Thomas, 1884., Eric Delson, David M. Alba, Stephen R. Frost, Dagmawit Abebe Getahun, Christopher C. Gilbert

Publications and Research

The purpose of this application, under Articles 23.9.3 and 81.1 of the Code, is to conserve the usage of the species-group name Simopithecus oswaldi Andrews, 1916 by giving it precedence over its senior subjective synonym Cynocephalus atlanticus Thomas, 1884. Theropithecus is a common to dominant member of the extinct primate community across Africa after 4 million years ago (Jablonski & Frost, 2010) and often co-occurred with extinct humans (Hominini); fossils are also known rarely across Eurasia (Roberts et al., 2014). Most fossil samples are currently included in Theropithecus oswaldi (Andrews, 1916), which is often divided into chrono-geographic subspecies. Cynocephalus atlanticus …

Bullet Ricochet Of Polymer Coated Bullets, Stephen Daly

Student Theses

Polymer coated bullets were designed to limit a shooter’s exposure to lead. However, despite the advantages that these bullets give there are still difficulties which arise in a forensic firearms examination. Unlike in a typical metal coated bullet, individualizing striations will typically not be imparted to a polymer coated bullet making it unable to be linked to a specific firearm. Due to this difficulty any information that can be gained at the scene of the crime could be crucial. Some obtainable information includes the angle of ricochet and the angle of incidence of the discharged bullet as well as traces …

Transmission Telescope Optical Dynamic Alignment, Viviana Vladutescu, Aaron J. Swank, Dzu K. Le, Calvin R. Robinson, O. Scott Sands

Publications and Research

The Integrated Radio Optical Communication System (iROC) is designed to transmit data between Mars and Earth by means of radio waves at 32.67 GHz (Ka band) and laser beam (LB) at 1550 nm, both transmitted via a combined telescope/antenna called a teletenna. The iROC terminal will provide “beaconless” operations to allow full function from the outer planets. In order to point without the aid of an uplink beacon, the proof of concept presented here is addressing the need for an accurate determination and control of the relative position of the LB with respect to a reference star.

The experiment presented …

Designing Atomic Edge Structures In 2d Transition Metal Dichalcogenides For Improved Catalytic Activity, Raymond R. Unocic, Xiahan Sang, Guoxiang Hu, Victor Fung, Jingsong Huang, Matthew G. Boebinger, Kai Xiao, Panchapakesan Ganesh

Publications and Research

Designing new materials for functional applications depends upon our ability to understand and correlate the materials structure and chemistry to functional material properties. This is even more important for two-dimensional (2D) materials where thicknesses are on the order of a single atom to a few-atomic layers; therefore, any structural or chemical modification at these length scales can have a profound effect on modifying physical and chemical properties. 2D transition metal dichalcogenides (TMDs) such as MoS2 have emerged as a promising catalyst for the hydrogen evolution reaction with defects such as vacancies and edges being linked to high catalytic active sites …

Using Data Science To Create An Impact On A City Life And To Encourage Students From Underserved Communities To Get Into Stem, Elena Filatova, Deborah Hecht

Publications and Research

In this paper, we introduce a novel methodology for teaching Data Science. Our methodology relies on the outlook of the student body in our college. Our college is an urban, commuter, HSI (Hispanic Serving Institution) school with 34% Hispanic and 29% Black students. 61% of our students come from households with an income of less than $30,000+. Thus, many students in our college come from the communities that are underrepresented in the STEM fields and in the decision-making positions in the government (on the city level, state level, country level). However, in our methodology, we want to flip the situation …

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Content Analysis Of Two-Year And Four-Year Data Science Programs In The United States, Elizabeth Milonas, Duo Li, Qiping Zhang

Publications and Research

Data has grown exponentially in the last decade, and this growth has resulted in vast challenges for both business and IT domains (Hassan & Liu, 2019). This growth has given rise to the Data Science field, which has also grown exponentially in the last few years (Hassan & Liu, 2019; Song & Zhu, 2016). The Data Science field has its origins in the statistics and mathematics domain (Cao, 2017b), but is now considered a multidisciplinary field (Aasheim et al., 2015). Data Science warrants knowledge of data analytics, programming, systems, applications, informatics, computing, communication, management, and sociology (Aasheim et al., 2015; …

Rezina Shams – The First Known Woman Geologist From Dhaka University (Bangladesh) To Obtain A Phd, Nazrul I. Khandaker

Publications and Research

Rezina Shams (Dhaka University geology graduate 1985; née Rezina Bashar) is the first known female geologist from Bangladesh to obtain a PhD in 1991 (University of Birmingham, UK). Rezina’s undergraduate and graduate education in geology at Dhaka University (DU) was at a time when only a handful of female students attended the program. Rezina’s debut into her geology career began with the Master Plan Organisation (MPO) and then the Bangladesh Atomic Energy Commission (1986). Rezina kept her aspirations alive, and eventually furthered her geoscience education to a PhD. Upon receiving a PhD in 1991 from the University of Birmingham under …

Experimental Observation Of Topological Z2 Excitonpolaritons In Transition Metal Dichalcogenide Monolayers, Mengyao Li, Ivan Sinev, Fedor Benimetskiy, Tatyana Ivanova, Ekaterina Khestanova, Svetlana Kiriushechkina, Anton Vakulenko, Sriram Guddala, Maurice Skolnick, Vinod M. Menon, Dmitry Krizhanovskii, Andrea Alù, Anton Samusev, Alexander B. Khanikaev

Publications and Research

The rise of quantum science and technologies motivates photonics research to seek new platforms with strong light-matter interactions to facilitate quantum behaviors at moderate light intensities. Topological polaritons (TPs) offer an ideal platform in this context, with unique properties stemming from resilient topological states of light strongly coupled with matter. Here we explore polaritonic metasurfaces based on 2D transition metal dichalcogenides (TMDs) as a promising platform for topological polaritonics. We show that the strong coupling between topological photonic modes of the metasurface and excitons in TMDs yields a topological polaritonic Z₂ phase. We experimentally confirm the emergence of one-way …

Quo Vadis Lakes Azuei And Enriquillo: A Future Outlook For Two Of The Caribbean Basin's Largest Lakes, Mahrokh Moknatian, Michael Piasecki

Publications and Research

Lakes Azuei (LA) and Enriquillo (LE) on Hispaniola Island started expanding in 2005 and continued to do so until 2016. After inundating large swaths of arable land, submerging a small community, and threatening to swallow a significant trade route between the Dominican Republic and Haiti; worries persisted at how far this seemingly unstoppable expansion would go. The paper outlines the approach to a look forward to answer this question vis-à-vis climate change scenarios developed by the Intergovernmental Panel on Climate Change (IPCC). It uses numerical representations of the two lakes, and it examines how the lakes might evolve, deploying three …