Physical Sciences and Mathematics Commons^™

Quantum Chemistry–Machine Learning Approach For Predicting Properties Of Lewis Acid–Lewis Base Adducts, Hieu Huynh, Thomas J. Kelly, Linh Vu, Tung Hoang, Phuc An Nguyen, Tu C. Le, Emily Jarvis, Hung Phan

Chemistry and Biochemistry Faculty Works

Synthetic design allowing predictive control of charge transfer and other optoelectronic properties of Lewis acid adducts remains elusive. This challenge must be addressed through complementary methods combining experimental with computational insights from first principles. Ab initio calculations for optoelectronic properties can be computationally expensive and less straightforward than those sufficient for simple ground-state properties, especially for adducts of large conjugated molecules and Lewis acids. In this contribution, we show that machine learning (ML) can accurately predict density functional theory (DFT)-calculated charge transfer and even properties associated with excited states of adducts from readily obtained molecular descriptors. Seven ML models, built …

Understanding Societal Values Of Chatgpt, Yidan Tang

McKelvey School of Engineering Theses & Dissertations

As Large language models (LLMs) become increasingly pervasive in various domains, it is crucial to ensure that their outputs adhere to societal values and ethical considerations. In this thesis, we investigate the alignment of ChatGPT, a recent state-of-the-art large language model developed by OpenAI, with societal values. Specifically, we define the problem of societal values of LLMs and assemble a representative collection of 7 datasets covering 4 topics related to societal values. In-context learning techniques are applied and appropriate prompts are designed. The performance of each dataset is measured using a standardized evaluation system focused on accuracy. We then display …

Development Of A 780 Nm External Cavity Diode Laser For Rubidium Spectroscopy, Catherine Sturner

Undergraduate Honors Theses

This thesis describes the work done to improve an external cavity diode laser. These improvements consisted of constructing an insulated housing to stabilize the temperature of the laser, tuning the proportional-integral-derivative feedback of the temperature controller, achieving resonance frequencies of rubidium, and implementing and optimizing feed-forward scanning of the frequency of the laser. The laser was then successfully used to measure the linewidth of another laser in the laboratory to better understand how that laser could be best used. The knowledge gained in this thesis can also be used to change the frequency of the laser to achieve other resonances …

Monoenergetic Neutrinos From Wimp Annihilations In Jupiter, George French

Undergraduate Honors Theses

Several important lines of evidence point to the existence of dark matter, but it has not yet been experimentally detected. There are several proposed candidates for what dark matter is like, the most popular being weakly interacting massive particles (WIMPs). It has been well-established in the literature that WIMPs would be captured by the Sun after scattering off of atomic nuclei to a velocity lower than the escape velocity. Over time, many WIMPs would be captured and begin to annihilate in the solar core; this would result in the production of kaons that decay at rest into monoenergetic 236 MeV …

Seeing What We Can't: Evaluating Implicit Biases In Deep Learning Satellite Imagery Models Trained For Poverty Prediction, Joseph O'Brien

Undergraduate Honors Theses

Previous studies have sought to use Convolutional Neural Networks for regional estimation of poverty levels. However, there is limited research into possible implicit biases in deep neural networks in the context of satellite imagery. In this work, we develop a deep learning model to predict the tertile of per-capita asset consumption, trained on satellite imagery and World Bank Living Standards Measurements Study data. Using satellite imagery collected via survey location data as inputs, we use transfer learning to train a VGG-16 Convolutional Neural Network to classify images based on per-capita consumption. The model achieves an $R^2$ of .74, using thousands …

Spatial Variability Of Alkali-Metal Polarization, Lauren Vannell

Undergraduate Honors Theses

An experiment was conducted at William & Mary to study how alkali polarization varies spatially in a spherical cell during the process of optical pumping. Similar cells are used to study the neutron via electron scattering from polarized 3He nuclei, and those experiments could be improved if alkali polarization is maximized and uniformly distributed throughout the cell. The results of this experiment indicate that the alkali polarization is non-uniform and more heavily concentrated on the side of the cell facing the pump laser.

Considering The Accuracy Of Fiat Boundaries: Ontology And Quantification, Lydia Troup

Undergraduate Honors Theses

Administrative boundaries - i.e., states, counties, or districts - are fiat boundaries; they exist purely as defined by human interpretation. Because of this, and despite their critical importance to government functions, the accuracy of data products claiming to represent such boundaries is difficult to measure. Here, I explore this topic using three boundary data sets: the open source geoBoundaries data set, the humanitarian UN OCHA’s Common Operational Datasets (COD), and Esri’s commercial administrative divisions 0 and 1 data sets in the Living Atlas. The accuracy of each was quantified as the percent overlap between each data set and an authoritative …

Evapotranspiration And Energy Balance Of Irrigated Urban Turfgrass, Matthew D. Miksch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water usage for irrigation is a big consumer of water resources in urban areas in Utah and other parts of the Intermountain Region of the Western United States. As populations continue to increase in these states, it is important to understand how much water is being used by urban landscapes in order to plan and manage future water resources. Evapotranspiration (ET), or the amount of water leaving a surface over a certain timeframe due to both transpiration from plants and evaporation from the soil, is a key variable in understanding how much water urban landscapes are really using to grow …

Getting The Dirt On Phosphorus Pollution In Mountain Lakes: Are Rising Soil Temperatures Contributing To Eutrophication In Mountain Watersheds?, Gordon O. Gianniny

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain watersheds provide a critical supply of clean water to millions of people around the world. In recent years, evidence of a concerning trend has emerged in these watersheds: rising phosphorus (P) concentrations. P often acts as the limiting nutrient in mountain lake ecosystems, so increasing P availability in mountain lakes and streams has the potential to drastically increase algal growth in these systems. In extreme cases, increasing mountain lake P concentrations may even cause harmful algal blooms that degrade downstream water quality. While the implications of rising P concentrations in mountain lakes are serious, the cause driving this widespread …

Examining Political Discourse On Online 8kun And Reddit Forums, Braden Mindrum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A recent example of political violence in the United States was that of the January 6, 2021, Capitol attack in connection with the certification of Joseph R. Biden’s victory over Donald J. Trump in the 2020 US presidential election. This thesis analyzes the events of January 6, 2021, through the lens of social media discourse. This thesis presents a workflow that acquired over 5 million 8kun and Reddit posts from various apolitical and political forums in the three months preceding and following the Capitol attack on January 6, 2021. Techniques from text analysis are then used to group forums according …

Coding Bootcamps - Perceptions And Outcomes, Logan L. Hendricks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis is focused on gathering, aggregating and analysing data related to software development coding bootcamps. It comprises of three major research initiatives: A coding bootcamp outcomes meta-analysis, a study on perspectives regarding white-label coding bootcamps, and the data analysis of a survey gathering long-term outcomes of coding bootcamp and certificate program graduates.

The first study aggregates graduate outcome data from the three main organizations that review coding bootcamp outcomes: CourseReport.com, SwitchUp.com and the Council on Integrity in Results Reporting (CIRR). The purpose of this meta-review is to establish a baseline dataset which is immediately utilized in my further research. …

Adversarial Swarming: A Groundwork For Multi-Drone Independent Interception Exercises Through Ma-Poca In Unity, Johnathan D. Kunz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As drones become more popular and easier to use, air spaces are becoming more congested. Airports, hospitals, and similar structures require controlled, safe airspaces and drones are increasingly a threat. Locally controlled airspace requires efficient removal of airborne threats to continue sensitive operations. Many methods have been investigated for removing drones from contested airspace. Generally these methods involve ground-based signal disruption, physical contact, or drone interception of a single intruder. In this work we present a drone interception model with a low-cost, low-capability group of short-range drones intercepting an incoming drone.

Examining Model Complexity's Effects When Predicting Continuous Measures From Ordinal Labels, Mckade S. Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many real world problems require the prediction of ordinal variables where the values are a set of categories with an ordering to them. However, in many of these cases the categorical nature of the ordinal data is not a desirable outcome. As such, regression models treat ordinal variables as continuous and do not bind their predictions to discrete categories. Prior research has found that these models are capable of learning useful information between the discrete levels of the ordinal labels they are trained on, but complex models may learn ordinal labels too closely, missing the information between levels. In this …

Exploring Numerical Simulations Of Localized Geomagnetic Disturbances, Elizabeth Vandegriff

Physics Dissertations

One of the prominent effects of space weather is the formation of rapid geomagnetic field variations on Earth’s surface driven by the magnetosphere-ionosphere system. These Geomagnetic Disturbances (GMDs) cause Geomagnetically Induced Currents (GICs) to run through ground-conducting systems. GMDs can often be high amplitude and small-scale (100-500 kilometers) and we classify these as Localized GMDs (LGMDs). LGMDs are both hazardous to the power grid and difficult to predict. Modeling LGMDs is therefore a critical step for risk mitigation but is complicated due to the dynamic and sometimes highly localized nature of the phenomena. At present, global magnetohydrodynamic (MHD) models of …

Developing Chemo-Proteomics Methods For Tyrosine Conjugation And Studies Of Organometallic Complexes Of Gold., Adway Ouseph Zacharias

Chemistry & Biochemistry Dissertations

The incredible changes in MS instrumentation since the late 1980s with the advent of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) has revolutionized protein chemistry. Mass spectrometry coupled with chemical crosslinking is a powerful tool to decipher protein structure and protein-protein interactions. A majority of commercially available crosslinkers target only few amino acid residues such as lysine, arginine and cysteine, thereby limiting the utility of this technology. The prospect of using chemical reagents to target amino acids is challenging since covalent labeling experiments are performed under physiological aqueous conditions that may be detrimental to the stability of these reagents. …

Novel Roles Of Standard And Non-Standard Null Lagrangians In Classical And Quantum Physics, Lesley Catherine Vestal

Physics Dissertations

The three known families of Lagrangians are standard, non-standard, and null Lagrangians. While Lagrangians are widely used in Physics for their ability to characterize physical systems, most of this work uses only standard Lagrangians. As such, standard Lagrangians have been studied in Physics for around three hundred years; however, non-standard Lagrangians for systems in Physics have been considered only for a few decades, and null have been ignored almost entirely. Although only some Lagrangians are null Lagrangians, all Lagrangians can be categorized as either standard or non-standard Lagrangians, meaning that there exist standard null Lagrangians and non-standard null Lagrangians. My …

Analysis Of Isotopic Isomers By Gas Chromatography And Molecular Rotational Resonance Spectroscopy And Enantioselective Method Development By Liquid Chromatography, Saba Aslani

Chemistry & Biochemistry Dissertations

This dissertation focuses on developing improved methods and a better understanding of gas and liquid chromatographic separation of isotopic isomers and enantiomers. The second and third chapters of this thesis discuss analytical determination of isotopic isomers using gas chromatography. Deuterated compounds have found applications in many fields. They are used in drug discovery due to increased stability and bioavailability and reduced toxicity of the deuterated drug molecules. Also, deuterated compounds are used to investigate reaction mechanisms and rate determining steps. One of the methods of synthesizing deuterated compounds is starting from lower molecular weight deuterated building blocks. Therefore, analysis and …

Model And Observation Comparisons Of Ionospheric Current Systems, Tre'shunda James

Physics Dissertations

The interaction between the dynamically changing solar wind and Earth’s magnetosphere results in several different current systems. The most relevant to space weather are the Birkeland currents, a.k.a field-aligned currents (FACs), that couple the magnetosphere to the ionosphere. These currents flow into and out of the ionosphere and are closed through the ionosphere by the horizontally flowing eastward and westward electrojets. This FAC-electrojet current system is responsible for some of the most beautiful and detrimental space weather impacts. The aurora borealis (or northern lights) in the Northern Hemisphere and aurora australis (or southern lights) in the Southern Hemisphere are displays …

Investigation Of Optical And Electrical Properties Of Noble Metal And Superconducting Thin Films And Design And Fabrication Of Metamaterial Solar Absorbers, Vivek Khichar

Physics Dissertations

An extensive study of light-matter interactions leading to the generation of photon drag voltage under surface plasmon resonance conditions in noble metal thin films was undertaken by performing a series of experimental measurements and numerical simulations. The drag voltage originates from a force that arises because of the transfer of momentum from incident light to electrons. This transfer of photon momentum leads to an electric current, which in turn results in the generation of drag voltage. The effect is particularly enhanced under surface plasmon resonance conditions and thereby reinforces the interaction between light and collective oscillations of the surface charges. …

Combining Chiral Chromatographic Stationary Phases And N-Derivatization Strategies For The Qualitative And Quantitative Analysis Of D-Amino Acids, D-Amino Acid Containing Peptides And D-Amino Acid Related Secondary Metabolites Using Liquid Chromatography, Sam Sung

Chemistry & Biochemistry Dissertations

Amino acids are essential building blocks in all life on Earth. It was first mistakenly believed that only L-amino acids were of biological relevance in higher organisms, and D-amino acids were laboratory artifacts or biologically irrelevant. It is well accepted today that various D-amino acids exist in different organisms, including humans, and some even play critical roles in biological pathways and processes. In addition, aberrant levels of certain D-amino acids have been reported in patients with varying diseases. It has been proposed that the aberrant variations in the levels of D-amino acids in biological fluids may serve as biomarkers for …

A Glimpse Into The Climate, Seasonality, Hydrological Cycle, Carbonate Chemistry And Marine Ecosystem Shift Of The Pre-Petm And The Petm Using Ncar Cesm1.2, Jiayi Wang

Earth & Environmental Sciences Dissertations

The Paleocene-Eocene Thermal Maximum (PETM, ~56 my ago, 170,000y event) is characterized by a negative δ13C excursion into the atmosphere. This event caused global temperature to increase by about 5-6 °C, followed by climate responses such as marine acidification, ocean stratification, shoaling of calcite compensation depth (CCD), stronger hydrological cycle, and significant changes in marine ecosystems. It is one of the very few analogies of today’s global warming climate and thus is valuable to study. It still holds much potential for research, including using the state-of-the-art model CESM1.2. Proxy records are limited due to the nature of geological preservation and …

Cellulose Nanocrystal Dielectric Elastomers, David Frailey

Theses and Dissertations

Optical devices, such as filters and sensors, have numerous advantages including compactness in size and immunity from electromagnetic interference. The fabrication of optical devices often requires precision and complicated processing, resulting in expensive and delicate components. Cellulose nanocrystals (CNCs) are biomaterials that can self-assemble into liquid crystals, similar to those used in electronic displays. This material can function as an optical grating by reflecting/transmitting circularly polarized light at certain wavelengths and viewing angles. Since gratings are building blocks of optical systems, like lasers and lidars, their fabrication at low costs will enable the further proliferation of optical technologies. Furthermore, if …

Extracting Patterns Of Semantic Roles From Accident Narratives, Soundarya Jayakumar

Theses and Dissertations

Accident databases are filled with rich information about accidents. Analyzing these datasets can reveal useful information which can be used to prevent similar accidents in the future. Policy makers, and safety management organizations can design appropriate measures based on the analysis done to prevent accidents. Besides structured data, crash reports include natural language narratives which contain valuable accident-related information which is otherwise not present in the structured data. Using natural language processing (NLP) techniques one can analyze these narratives and mine hidden patterns of accidents from them. The thesis focuses on developing an algorithm to extract common patterns of semantic …

The Search For The Four-Electron Reduced Intermediate In The Cytochrome C Nitrite Reductase (Ccnir) - Catalyzed Reduction Of Nitrite, Victoria Lynn Mandella

Theses and Dissertations

Although there are many nitrogen species in the nitrogen cycle, nitrite occupies a centralrole. Nitrite can either reduce to ammonium or dinitrogen or oxidize to nitrate. Ammonium and nitrate can be found in the environment; however, problems arise when the accumulation of these nitrogen species leads to eutrophication in aquatic environments. High ammonium or nitrate levels in lakes or other bodies of water can lead to the overgrowth of algae, which causes the blockage of sunlight to different species below the water surface. Imbalance in the ecosystem is a serious environmental issue that can be addressed by further studying and …

Vision-Based Object Manipulation For Activities Of Daily Living (Adl) Assistance Using Assistive Robot, Md Tanzil Shahria

Theses and Dissertations

Upper and lower extremity (ULE) functional deficiencies, which limit a person's ability to perform everyday tasks, have increased at an alarming rate over the past few decades. It is essential for individuals with impairments to take care of themselves without requiring a significant amount of support from other individuals. Few assistive devices are available in the market to make their life comfortable, yet controlling them sometimes becomes challenging for this group of people. Robotic devices are emerging as assistive devices to assist individuals with limited ULE functionalities in activities of daily living (ADL). As most of these devices only allow …

Estimating Energy Cost Of Physical Activities From Video Using 3d-Cnn Networks, Pragya Shrestha Chansi

Theses and Dissertations

This research proposes a machine learning model that can estimate the energy cost of physical activities from video input. Currently, wearable sensors are commonly used for this purpose, but they have limitations in terms of practicality and accuracy. A deep learning model using three dimensional convolutional neural network (3D-CNN) architecture was used to process the video data and predict the energy cost in terms of metabolic equivalents (METs). The proposed model was evaluated on a dataset of physical activity videos and achieved an average accuracy of 71% on energy category prediction task and an root mean squared error (RMSE) of …

Numerical Simulations Of Tidal Disruption Events, Alexandra Elise Spaulding

Theses and Dissertations

The detection of supermassive black holes (SMBH) in our universe has proven to be a challenge. One way to find an SMBH in a quiescent, inactive galaxy is through a tidal disruption event, or a TDE. A TDE occurs when a star is slightly perturbed and is subsequently disrupted by the SMBH. When this happens, part of the debris from the disrupted star remains bound to the SMBH while the rest is unbound. The SMBH accretes the bound matter and reveals their presence by a temporary X-ray flare, lasting a few months. Using conservation of energy, the fallback rate of …

Leveraging Biomedical Ontological Knowledge To Improve Clinical Term Embeddings, Fuad Hatem Abuzahra

Theses and Dissertations

ABSTRACT Leveraging Biomedical Ontological Knowledge to Improve Clinical Term Embeddings by Fuad Abu Zahra The University of Wisconsin-Milwaukee, 2023 Under the Supervision of Dr. Rohit J. Kate This research is on obtaining and using word embeddings for natural language processing tasks in the biomedical domain. Word embeddings are vector representations of words commonly obtained from large text corpora. This research leverages the biomedical ontology of SNOMED CT as an alternate source for obtaining embeddings for clinical terms. The existing graph-based methods can only give embeddings for concepts (i.e., nodes of the graph) of an ontology, hence we developed a novel …

The Characterization Of Atmospheric Turbulence And Its Effect On Laser Beam Propagation, Michael Cox

All Theses

Having a controlled environment to measure atmospheric turbulence is essential to understanding its effects on different laser beam characteristics. The Clemson Variable Turbulence Generator (VTG) has the capability to propagate a laser beam up to 100 m and be able to dial many turbulence settings up to a heat flux of 357 W/m². A high-speed camera, power detector, and high-resolution temperature probes characterize the VTG with theoretical turbulence spectrums. The exponent associated with the Rayleigh-Bénard (RB) temperature structure constant equation is studied. Two different laser beam profiles are used throughout this work: Gaussian and Asymmetric Perfect Vortex (APV). …

An Investigative Study Of Potential Factors That Contribute To High Under-Five Mortality Rate In Africa, David Banahene

Theses and Dissertations

Under-Five Mortality remains a significant challenge in developing countries, especially in Africa. The United Nations has implemented various measures, such as the Millennium Development Goals (MDGs) and Sustainable Development Goals (SDGs), to combat this issue. However, the success of these initiatives is uncertain. Our study investigates the social, economic, and environmental factors contributing to high Under-Five Mortality rates in African countries, using data from 1985 to 2020.We analyzed 53 African countries, partitioning them into training (45 countries) and testing data (8 countries). We conducted Multiple Linear Regression analysis and assessed the model performance using R-squared values and Root-Mean-Squared-Error (RMSE) values. …