Physical Sciences and Mathematics Commons^™

Decomposition Rates Of Spartina Alterniflora (Smooth Cordgrass) In Natural And Created Salt Marshes In Coastal Louisiana, Allison Benelli

Honors Theses

No abstract provided.

Mitochondrial Dna Genetic Variation And Structure In Smalltooth Sawfish (Pristis Pectinata), Keyla N. Pruett

Honors Theses

No abstract provided.

Bert Argues: How Attention Informs Argument Mining, Ting Chen

Honors Theses

Argument mining is the automatic identification and extraction of structure from argumentative language. Previous works have constrained the argument structure to forming strictly trees in order to utilize efficient tree-specific techniques. However, arguments in the wild are unlikely to exhibit this constrained structure. Given the recent trend of fine-tuning large pre-trained models to reach state of the art performance on a variety of Natural Language Processing (NLP) tasks, we look to leverage the power of these deep contextualized word embeddings towards the task of non-tree argument mining. In this paper, we introduce a new pipeline which utilizes pre-trained BERT based …

Best Practices In Industry And Cse Senior Design, Conner Hallett

Honors Theses

The widespread use of Agile practices in the software development industry creates the need for new college graduates to be adept in Agile processes and teams. The University of Nebraska-Lincoln’s Computer Science and Engineering (CSE) Senior Design courses gives students an introduction to such processes, but is met with many challenges in doing so, such as time constraints and student inexperience. Following a detailed look at the Scrum Agile framework and its expanded practices in industry, potential improvements for CSE Senior Design’s practice of Agile are suggested. These include the creation of resource forums for students to accelerate the early …

Variable Autoencoders For Biosensor Data Augmentation, Solomon Kim

Honors Theses

Over the past decade machine learning and artificial intelligence's resurgence spawned the desire to mimic human creative ability. Initially attempts to create images, music, and text flooded the community, though little has been learned regarding constrained, one-dimensional data generation. This paper demonstrates a variational autoencoder approach to this problem. By modeling biosensor current and concentration data we aim to augment the existing dataset. In training a multi-layer neural network based encoder and decoder we were able to generate realistic, original samples., These results demonstrate the ability to realistically augment datasets, improving training of machine learning models designed to predict concentration …

Fact-Checking Of Claims From The English Wikipedia Using Evidence In The Wild, Aalok Sathe

Honors Theses

Automated fact checking is a task in the domain of Natural Language Processing that deals with the verification of claims using evidence. Fact checking is becoming increasingly important as large amounts of human-generated information accumulate online. In the recent past, our society has witnessed large-scale spread of disinformation via the internet that has time and again led to noticeable disruptions in the fabric of society. Fact-checking would help mitigate the spread of disinformation by allowing large magnitudes of content to be automatically evaluated for disinformation. In this work, we construe and tackle multiple subtasks of fact checking using labeled data …

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Study Of Neon Collisional Negative Ion Compound Resonance Using A Trochoidal Electron Monochromator, Will Brunner

Honors Theses

This thesis describes the experimental apparatus and procedure used to measure the excitation function of the 2p⁵3p ³D₃ state of neon. First I describe the effect on this excitation of negative ion resonances and previous experiments to measure the excitation function, as well as suggestions for future applications of such studies. Then the experimental apparatus is described in three parts. The vacuum system uses a turbomolecular pump to decrease the pressure of the chamber to as low as 4*10^-9 Torr. The electron beam system incorporates a trochoidal electron monochromator to send a highly monochromatic beam …

Mass Incarceration In Nebraska: Data And Historical Analysis Of Inmates From 1980-2020, Anna Krause

Honors Theses

This study examines Nebraska Department of Corrections inmate data from 1980-2020, looking specifically at inmate demographics and offense trends. State-of-the-art data analysis is conducted to collect, modify, and visualize the data sources. Inmates are organized by each decade they were incarcerated within. The current active prison population is also examined in their own research group. The demographic and offense trends are compared with previous local and national research. Historical context is given for evolving trends in offenses. Solutions for Nebraska prison overcrowding are presented from various interest groups. This study aims to enlighten all interested Nebraskans on who inhabits their …

Advanced Technologies In Music Production And Collaboration, David Besonen

Honors Theses

My Honors Senior Creative Project was to compose and produce a short album of original music alongside talented musicians here at the University of Nebraska-Lincoln (UNL) as well as around the world.

Identifying, Analyzing, And Using Discriminatory Variables For Classification Of Neutrino Signal And Background Noise In Multivariate Analysis In The Askaryan Radio Array Experiment, Jesse Osborn

Honors Theses

The Askaryan Radio Array Experiment, located near the South Pole, works to pinpoint specific instances of neutrinos from outside the solar system interacting with nucleons inside the Antarctic ice, emitting radio waves. I have taken data from the ARA stations which is presumed to be background noise and compared it to simulated data meant to look like a neutrino signal. I developed a suite of variables for discrimination between the two data sets, using a computer algorithm to generate a single output variable which can be used to distinguish noise events from signal events. I maximized this discrimination process for …

Modeling Of Covid-19 Utilizing Various Compartmental Models To Predict Infection Rates Throughout Michigan, Colleen M. Staniszewski

Honors Theses

Compartmental modeling is a method of employing math to create a visual representation of a disease interacting with a select population, typically used in epidemiology analyses. This project applies compartmental modeling equations to data collected on the various aspects of COVID-19 in Michigan. Comparing current data to past predictive models, as well as the visual representations that were developed through the various compartmental modeling methods, allows an assessment of the effects of the preventative measures taken by the state, the various rates at which the infection is able to spread, as well as the potential path and spread of the …

Electron Beam Dispersion Compensator Using A Wien Filter, Jackson Lederer

Honors Theses

When an electron beam travels through space, it spreads out over time which impedes the ability to work with short electron pulses in the lab. A Wien filter is a device consisting of perpendicular electric and magnetic fields which filters charged particles based on their velocities. For a specific velocity, the two forces from the two fields in the filter cancel each other out letting charges with that velocity travel straight through the filter. Charges moving at other speeds are deflected as they have a net force applied to them from the filter. If a particle is deflected from the …

Choosing Isds As A Major: Predictive Analysis, Sarah Johnson

Honors Theses

No abstract provided.

Using Difference-In-Differences Analysis And The Kocyk Geometric Lag Model To Estimate Aspects Of Carbon Tax Effectiveness In Nordic Countries, Kyle Riley

Honors Theses

This paper generally looks at the connections between carbon taxes and carbon emission levels in Nordic countries over a period from the 1960s to the early 2010s. Most of the existing literature on this topic looks at and finds that carbon taxes do have a significant impact upon carbon emissions levels in some countries while not in others. In many countries which have this policy there is not a significant impact that can be seen and there is a discussion as to why this might be the case and what needs to be done to fix these potential issues to …

Porphyrins And Porphyrin Applications, Derek Girouard

Honors Theses

Porphyrins are a macrocyclic compound that can be modified in a myriad of ways offering useful and unique applications. These applications can range from ion sensing to catalysts in reactions. However, some of the most interesting applications revolve around medical and therapeutic treatments. Porphyrin derivatives can be used in processes known as photodynamic therapy (PDT) and photothermal therapy (PTT) to treat cancerous tumors. Porphyrins have been used in many ways in the body by their attachment to a variety of backbone structures. Porphyrins have potential to be widely utilized in therapeutic treatments as they are further studied and adapted to …

The Evolution Of Deuterium In The Pharmaceutical Industry And Its Effects On Methods Of Deuterium Incorporation, Angela Martinez

Honors Theses

The substitution of deuterium, an isotope of hydrogen containing one proton and one neutron, for a hydrogen has far reaching effects on the behavior of the compound. Scientists have been utilizing the effects of deuterium since 1961. The primary purpose for deuterium has been concentrated in the development of internal standards for NMR and mass spectrometers, due to their relative ‘silence’ in these studies, allowing scientists to elucidate mechanisms and trace a compound's movement throughout the body. However, recently, in addition to the use of deuterium as a standard, it has been added to developing or previously created pharmaceutical compounds …

Artificial Reefs: A History, A Science, A Technology, Mairead D. Farrell

Honors Theses

Over the past 60 years, artificial reefs have expanded beyond the definition of a technology, and in turn have developed into a unique branch of marine science. To better emphasize this growth and separation, a brief history of artificial reef development and usage in chapter two shows some of the key shifts over time in this technology’s purpose and the materials used to achieve that goal. Likewise, to indicate the scientific development of artificial reefs as a branch of marine science, their usage for discovery and research is recorded in chapter three, along with the exponential increase in published scientific …

Investigating The Agn-Merger Connection Using Close Galaxy Pairs In The Candels Fields, Sean L. Dougherty

Honors Theses

Galaxy mergers are catastrophic events in that they greatly change the properties of the galaxies involved. Observations of the nearby universe suggest that they may also be able to trigger active galactic nuclei (AGN) even prior to the final coalescence, though there is much controversy surrounding this belief, particularly at high redshifts. In order to address this question, we have assembled a large sample of photometric galaxy pairs within the GDS and EGS fields of the CANDELS survey. We use photometric redshift probability distribution functions and the combined redshift probability function to assign probabilities for each projected pair. We incorporate …

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO₄ complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …

A Generalized Polar-Coordinate Integration Formula, Oscillatory Integral Techniques, And Applications To Convolution Powers Of Complex-Valued Functions On $\Mathbb{Z}^D$, Huan Q. Bui

Honors Theses

In this thesis, we consider a class of function on $\mathbb{R}^d$, called positive homogeneous functions, which interact well with certain continuous one-parameter groups of (generally anisotropic) dilations. Generalizing the Euclidean norm, positive homogeneous functions appear naturally in the study of convolution powers of complex-valued functions on $\mathbb{Z}^d$. As the spherical measure is a Radon measure on the unit sphere which is invariant under the symmetry group of the Euclidean norm, to each positive homogeneous function $P$, we construct a Radon measure $\sigma_P$ on $S=\{\eta \in \mathbb{R}^d:P(\eta)=1\}$ which is invariant under the symmetry group of $P$. With this measure, we prove …

Mot-Based Lifetime Measurements Of Potassium-39 5p1/2 And 5p3/2 States, Huan Q. Bui

Honors Theses

This thesis presents measurements of the lifetimes of 5p1/2 and 5p3/2 of K39 via exciting a cloud of K39 atoms in a magneto-optical trap by a linearly-polarized pulse of 405 nm light followed polarization-specific, time-resolved fluorescence detection. We find that $\tau_{5p1/2} = $ 138.8 $\pm$ 1.6 ns, which is consistent with past measurements \cite{triumf}, \cite{berends} and calculations \cite{safranova}. The $\tau_{5p3/2}$ measurement is naturally more involved since quantum beats due to hyperfine and Zeeman effect are present. Our observation of $\tau_{5p3/2} =$ 137.6 $\pm$ 3.1 ns and $\tau_{5p3/2} =$ 136.0 $\pm$ 2.4 ns, obtained from two slightly different approaches, are compared …

Visualizing The Range Of Glaciers: Science, Art And Narrative, Claire E. Waichler

Honors Theses

Glaciers are sensitive indicators and data keepers of climatic change. The glaciers of the North Cascades, Washington, also have significant economic and cultural value as they are enmeshed in hydroelectricity generation, terrestrial and aquatic ecology, and human communities. My project approaches the current climate crisis by examining the past, present and future of the glaciers of the North Cascades through the two lenses of art and science. I review and contextualize the last century of glacier research in the North Cascades to identify patterns of glacier change and how this affects ecological and human communities. Overlaid upon my literature review, …

Pollen: A Secure, Decentralized Wireless Communication Platform, Max Perrello

Honors Theses

In this article, we detail an encrypted, internet-independent messaging platform, of which we built a prototype. This thesis also describes the challenges faced in the process, as well as potential future enhancements.

Convolutional Audio Source Separation Applied To Drum Signal Separation, Marius Orehovschi

Honors Theses

This study examined the task of drum signal separation from full music mixes via both classical methods (Independent Component Analysis) and a combination of Time-Frequency Binary Masking and Convolutional Neural Networks. The results indicate that classical methods relying on predefined computations do not achieve any meaningful results, while convolutional neural networks can achieve imperfect but musically useful results. Furthermore, neural network performance can be improved by data augmentation via transposition – a technique that can only be applied in the context of drum signal separation.

Counting Conjugacy Classes Of Elements Of Finite Order In Compact Exceptional Groups, Qidong He

Honors Theses

Given a compact exceptional group $G$ and $m,s\in\mathbb{N}$, let $N(G,m)$ be the number of conjugacy classes of elements of order $m$ in $G$, and $N(G,m,s)$ the number of such classes whose elements have $s$ distinct eigenvalues. In string theory, the problem of enumerating certain classes of vacua in the string landscape can be rephrased in terms of the study of these quantities. We develop unified combinatorial algorithms based on Burnside's Lemma that can be used to compute both quantities for each of the five compact exceptional groups. Thus, we provide a combinatorial, alternative method to that of Djoković and extend …

Perceptually Improved Medical Image Translations Using Conditional Generative Adversarial Networks, Anurag Vaidya

Honors Theses

Magnetic resonance imaging (MRI) can help visualize various brain regions. Typical MRI sequences consist of T1-weighted sequence (favorable for observing large brain structures), T2-weighted sequence (useful for pathology), and T2-FLAIR scan (useful for pathology with suppression of signal from water). While these different scans provide complementary information, acquiring them leads to acquisition times of ~1 hour and an average cost of $2,600, presenting significant barriers. To reduce these costs associated with brain MRIs, we present pTransGAN, a generative adversarial network capable of translating both healthy and unhealthy T1 scans into T2 scans. We show that the addition of non-adversarial …

Estimating Heading From Optic Flow With Neural Networks, Natalie T. Maus

Honors Theses

Humans have a remarkable ability to estimate their direction of self-motion, or heading, based on visual input stimulus (optic flow). Machines, on the other hand, have a difficult time with this task, especially when flow is introduced that is inconsistent with the motion of the observer. For example, when moving objects enter the field of view, their motion provides inconsistent flow data which often disrupts heading estimates of current heading estimation models. We investigate the ability of neural networks to estimate heading from optic flow data and the limitations of these models when different variations of inconsistent flow are introduced. …

A Hybrid Decision Tree - Neural Network (Dt-Nn) Model For Predictive Maintenance Applications In Aircraft, Jarrod Carson

Honors Theses

As the Age of Information has evolved over the last several decades, the demand for technology which stores, analyzes, and utilizes data has increased substantially. For countless industries such as the medical, retail, and aircraft industries, such technology is crucial to their operation. This project proposes a hybrid machine learning model consisting of Decision Trees and Neural Networks which is able to classify data of varying volume and variety effectively and efficiently. The model’s structure consists of a decision tree with each node of the tree containing a neural network trained to classify a specific category of the output using …

Developing A Deterministic Polymorphic Circuit Generator Using Random Boolean Logic Expansion, Trinity Stroud

Honors Theses

Securing applications on untrusted platforms can involve protection against legitimate endusers who act in the role of malicious reverse engineers and hackers. Such adversaries have access to the full execution environment of programs, whether the program comes in the form of software or hardware. In this thesis, we consider the nature of obfuscating algorithms that perform iterative, stepwise transformation of programs into more complex forms that are intended to increase the complexity (time, resources) for malicious reverse engineers.

We consider simple Boolean logic programs as the domain of interest and examine a specific transformation technique known as Iterative Selection and …