Physical Sciences and Mathematics Commons^™

Smoothed Bounded-Confidence Opinion Dynamics On The Complete Graph, Solomon Valore-Caplan

HMC Senior Theses

We present and analyze a model for how opinions might spread throughout a network of people sharing information. Our model is called the smoothed bounded-confidence model and is inspired by the bounded-confidence model of opinion dynamics proposed by Hegselmann and Krause. In the Hegselmann–Krause model, agents move towards the average opinion of their neighbors. However, an agent only factors a neighbor into the average if their opinions are sufficiently similar. In our model, we replace this binary threshold with a logarithmic weighting function that rewards neighbors with similar opinions and minimizes the effect of dissimilar ones. This weighting function can …

Targeted Content-Sharing In A Multi-Group Dtn Application Using Attribute-Based Encryption, Xiaofei Cao, Shudip Datta, Ram Charan Bolla, Sanjay Kumar Madria

Computer Science Faculty Research & Creative Works

In a battlefield, multiple groups operate with different missions, but their missions and groups can dynamically change based on the evolving situation. Due to the unavailability of network infrastructure after deployment, group members form a Delay Tolerant Network (DTN) which is prone to security attacks. Hence, based on the mission attributes, group memberships, nodes' interests, and data tags determination, targeted contents need to be distributed in a secure fashion to different users. Though existing Attributes Based Encryption (ABE) can provide security of information, revoking a member from a group is always an issue in DTN as the Attribute Authority (AA) …

Multi-Agent Pathfinding In Mixed Discrete-Continuous Time And Space, Thayne T. Walker

Electronic Theses and Dissertations

In the multi-agent pathfinding (MAPF) problem, agents must move from their current locations to their individual destinations while avoiding collisions. Ideally, agents move to their destinations as quickly and efficiently as possible. MAPF has many real-world applications such as navigation, warehouse automation, package delivery and games. Coordination of agents is necessary in order to avoid conflicts, however, it can be very computationally expensive to find mutually conflict-free paths for multiple agents – especially as the number of agents is increased. Existing state-ofthe- art algorithms have been focused on simplified problems on grids where agents have no shape or volume, and …

Inhibitors Of Alpha-Synuclein Aggregation, Jemil Ahmed

Electronic Theses and Dissertations

Alpha-Synuclein (αS) – a neuronal, disordered, presynaptic protein – aggregates into amyloid fibrils and accumulates in the substantia nigra pars compacta of Parkinson's Disease (PD) patients. The aggregation and accumulation of αS amyloid fibrils leads to death of dopaminergic neurons; a hallmark of PD. Although it’s not clear why αS aggregates, prior studies have found that intrastriatal injection of fibril alone is sufficient to cause PD pathology in mouse and non-human primates models. These observations implicate αS as a therapeutic target against PD.

Unfortunately, there are three caveats when attempting to target αS. First, αS is a neuronal protein expressed …

Model-Based Testing Of Smart Home Systems Using Efsm, Cefsm, And Fsmapp, Afnan Mohammed Albahli

Electronic Theses and Dissertations

Smart Home Systems (SHS) are some of the most popular Internet of Things (IoT) applications. In 2021, there were 52.22 million smart homes in the United States and they are expected to grow to 77.1 million in 2025 [71]. According to MediaPost [74], 69 percent of American households have at least one smart home device. The number of smart home systems poses a challenge for software testers to find the right approach to test these systems. This dissertation employs Extended Finite State Machines (EFSMs) [6, 24, 105], Communicating Extended Finite State Machines (EFSMs) [68] and FSMApp [10] to generate reusable …

On Loop Commutators, Quaternionic Automorphic Loops, And Related Topics, Mariah Kathleen Barnes

Electronic Theses and Dissertations

This dissertation deals with three topics inside loop and quasigroup theory. First, as a continuation of the project started by David Stanovský and Petr Vojtĕchovský, we study the commutator of congruences defined by Freese and McKenzie in order to create a more pleasing, equivalent definition of the commutator inside of loops. Moreover, we show that the commutator can be characterized by the generators of the inner mapping group of the loop. We then translate these results to characterize the commutator of two normal subloops of any loop.

Second, we study automorphic loops with the desire to find more examples of …

Expanding The Network Evaluation Toolkit: Combining Social Network Analysis & Qualitative Comparative Analysis, Debbie Gowensmith

Electronic Theses and Dissertations

Collective action networks are complex systems of interrelated individuals or groups that come together for a common social change purpose (Ernstson, 2011). Researchers have used social network analysis (SNA) to examine the relationship structures and characteristics of collective action networks. However, determining whether collective action networking produces outcomes has been challenging because networks are complex, affected by context, and produce interdependent data. I addressed these challenges by pairing SNA with qualitative comparative analysis (QCA), a configurational comparative method. Using QCA, researchers can tease out which conditions are necessary or sufficient to produce an outcome. I analyzed a collective action network …

Characterization Of Cyclopropyl Synthases Involved In The Maturation Of Ribosomally Synthesized And Posttranslationally Modified Peptides, Yi Lien

Electronic Theses and Dissertations

Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a large class of natural products with significant human health implications. RiPPs are synthesized from a genetically encoded precursor peptide that undergoes significant modifications by maturing enzymes, or maturases. Recently, radical-S-adenosylmethionine (rSAM) enzymes have emerged as an important family of RiPP maturases. rSAM enzymes have been shown to install ether, thioether, and carbon-carbon bonds on the precursor peptide. These modifications usually define the backbone structure of the mature RiPP. This thesis describes the characterization of a novel RiPP modification catalyzed by the radical S-adenosylmethionine enzyme TigE. TigE belongs to the TIG biosynthetic …

Using The Fraction Of Missing Information (Fmi) In Selecting Auxiliary Variables To Impute Missingness In Confirmatory Factor Analysis (Cfa), Dareen Taha Alzahrani

Electronic Theses and Dissertations

This study aimed to investigate the effectiveness of using the fraction of missing information (FMI) to select auxiliary variables in imputing missing data in confirmatory factor analysis (CFA). This was done by conducting two studies (a simulation study and an empirical study). A Monte Carlo simulation technique was used to compare the performance and the effect of the restrictive strategy based on FMI and the inclusive strategy on parameter estimate bias and parameter estimate efficiency. The missing data mechanisms, missing data proportion, correlation strength between the analysis variables and auxiliary variables, and the inclusive and restrictive strategies were assessed in …

Examining The Credibility Of Story-Based Causal Methodologies, Megan E. Kauffmann

Electronic Theses and Dissertations

The purpose of this study was to explore how evaluators justify using story-based methodologies when examining causality. The two primary research questions of the study included: 1) what arguments are made by evaluators to justify the credibility of story-based causal methodologies to evaluation stakeholders; and 2) from the perspective of evaluators, how do contextual factors influence whether story-based causal methodologies are perceived as credible by evaluation stakeholders? A case study was conducted to examine the cases of four evaluators who had experience implementing a story-based methodology in an evaluation. Data collection procedures included two interviews with each participant and a …

Could Alexa Increase Your Social Worth?, Peter Tripp

Electronic Theses and Dissertations

People have historically used personal introductions to build social capital, which is the foundation of career networking and is perhaps the most effective way to advance a career (Lin, 2001). With societal changes, such as the pandemic (Venkatesh & Edirappuli, 2020), and the increasing capabilities of Artificial Intelligence (AI), new approaches may emerge that impact societal relationships. Social capital theory highlights the need for reciprocal agreements to establish the trust between parties (Gouldner, 1960). My theoretical prediction and focus of this research include two principles: The impact of reciprocity in evaluating trust of the source of the introduction and the …

Understanding The Impacts Of Urban Agriculture In Gentrifying Neighborhoods In Denver, Kate Johnson

Electronic Theses and Dissertations

Urban Agriculture is prominent in cities across the United States and has been studied in relation to food security, sustainability, and gentrification. Urban agriculture is context specific and can include individual gardens, community gardens, guerilla gardening, and urban farms. Urban agriculture is a product of the community it is based in, depending on politics, history, and social environments. For these reasons, the relationship between urban agriculture and the community is an area where more research is needed. This thesis explores the role visible gardens play in community building, sustainability, and food security in gentrifying neighborhoods in Denver. Through qualitative methods …

Digital Searching: A Grounded Theory Study On The Modern Search Experience, Nicolas Armando Parés

Electronic Theses and Dissertations

This Grounded theory study explores US adults' modern information search process as they pursue information through digital search user interfaces and tools. To study the current search process, a systematic grounded theory methodology and two data collection methods, a think-aloud protocol and semi-structured interviews, are used to develop the theory. The emerging theory addressed two tightly connected research questions that asked, “What is the process by which humans search and discover information?” and “What is the process by which search and discovery interfaces and tools support the modern search process?”

The study collects participant data from US adults who have …

Classification Of Electropherograms Using Machine Learning For Parkinson’S Disease, Soroush Dehghan

Electronic Theses and Dissertations

Parkinson’s disease (PD) is a neurodegenerative movement disorder that progresses gradually over time. The onset of symptoms in people who are suffering from PD can vary from case to case, and it depends on the progression of the disease in each patient. The PD symptoms gradually develop and exacerbate the patient’s movements throughout time. An early diagnosis of PD could improve the outcomes of treatments and could potentially delay the progression of this disorder and that makes discovering a new diagnostic method valuable. In this study, I investigate the feasibility of using a machine learning (ML) approach to classify PD …

Directly Polymerizable Co Releasing Molecules, Jackson Snow

Electronic Theses and Dissertations

Despite the commonly held consensus that carbon monoxide (CO) is toxic, it has been shown to be an essential signaling molecule in the human neuronal system and has been noted to have anti-inflammatory properties, act as a vasodilator, have anti-proliferative impacts on tumors, and many other beneficial effects. The current limitation to using CO as a therapeutic molecule is delivering the proper dosages using CO releasing molecules (CORMs) without exhibiting toxicity. The first chapter of this thesis will review the biological significance of CO in biological systems, the limitations of existing CORMs, and the properties of diphenylcyclopropenone (DPCP) that make …

Lipophilic Probes For Cellular Ethylene Detection, Morgan R. Brown

Electronic Theses and Dissertations

The structure of ethylene is simple, yet its biological effects are significant. When considering its role in biology it is almost exclusively regarded as a plant hormone. Research on ethylene from plants was progressed by several advancements in analytical instrumentation, from its discovery to elucidation of its signaling pathway. There is currently limited understanding of ethylene’s role in mammals, but evidence suggests that it may be a biomarker for oxidative stress! Additional tools and technology are crucial to study this surprising and important signaling role in mammals. Our group has developed molecular ethylene probes as a strategy to detect ethylene …

Frequency Analysis Of Trabecular Bone Structure, Daniel Parada San Martin

Electronic Theses and Dissertations

Medical data is hard to obtain due to privacy laws making research difficult. Many databases of medical data have been compiled over the years and are available to the scientific community. These databases are not comprehensive and lack many clinical conditions. Certain type of medical conditions are rare, making them harder to obtain, or are not present at all in the aforementioned databases. Due to the sparsity or complete lack of data regarding certain conditions, research has stifled. Recent developments in machine learning and generative neural networks have made it possible to generate realistic data that can overcome the lack …

Humanizing Computational Literature Analysis Through Art-Based Visualizations, Alexandria Leto

Electronic Theses and Dissertations

Inequalities in gender representation and characterization in fictional works are issues that have long been discussed by social scientists. This work addresses these inequalities with two interrelated components. First, it contributes a sentiment and word frequency analysis task focused on gender-specific nouns and pronouns in 15,000 fictional works taken from the online library, Project Gutenberg. This analysis allows for both quantifying and offering further insight on the nature of this disparity in gender representation. Then, the outcomes of the analysis are harnessed to explore novel data visualization formats using computational and studio art techniques. Our results call attention to the …

Local-Global Results On Discrete Structures, Alexander Lewis Stevens

Electronic Theses and Dissertations

Local-global arguments, or those which glean global insights from local information, are central ideas in many areas of mathematics and computer science. For instance, in computer science a greedy algorithm makes locally optimal choices that are guaranteed to be consistent with a globally optimal solution. On the mathematical end, global information on Riemannian manifolds is often implied by (local) curvature lower bounds. Discrete notions of graph curvature have recently emerged, allowing ideas pioneered in Riemannian geometry to be extended to the discrete setting. Bakry- Émery curvature has been one such successful notion of curvature. In this thesis we use combinatorial …

Bicycles And Transit: Weather Or Not: A Study On The Effect Of Weather And Air Quality On Bicycle-Transit, Bicycle, Rail Transit Counts In Denver, Christiana M. Fairfield

Electronic Theses and Dissertations

The movement of people and goods within metropolitan areas is critically important to the operational efficiency and functionality of cities. This study explores the influence of local weather conditions and the air quality index on bicycle-transit user in Denver, Colorado. Based on bicycle-transit having two key components, bicycle and transit, the effect of local weather conditions and the air quality index is also explored with bicycle use and rail-transit usage. Key findings include: (1) the most significant variable across all three modes is temperature, (2) for bicycle-transit and bicycle use, there is a steady increase in ridership as temperatures increase …

Mis-Specification Of Functional Forms In Growth Mixture Modeling: A Monte Carlo Simulation, Richa Ghevarghese

Electronic Theses and Dissertations

Growth mixture modeling (GMM) is a methodological tool used to represent heterogeneity in longitudinal datasets through the identification of unobserved subgroups following qualitatively and quantitatively distinct trajectories in a population. These growth trajectories or functional forms are informed by the underlying developmental theory, are distinct to each subgroup, and form the core assumptions of the model. Therefore, the accuracy of the assumed functional forms of growth strongly influences substantive research and theories of growth. While there is evidence of mis-specified functional forms of growth in GMM literature, the weight of this violation has been largely overlooked. Current solutions to circumvent …

Measurements Of Atmospheric Radicals, Heather L. Runberg

Electronic Theses and Dissertations

Atmospheric particulate matter (PM) is a global health concern. PM_2.5 is formed primarily through combustion processes such as automobile use and industrial activity. Natural sources of PM_2.5 result from events like volcanos and wildfires. Upon inhalation, PM_2.5 is small enough to travel deep into the lungs where it can form reactive oxygen species (ROS), such as hydroxyl radical (OH), causing oxidative damage to pulmonary tissues. PM_2.5 has been linked to cardiopulmonary diseases such as asthma, chronic obstructive pulmonary disease (COPD), and high blood pressure.

PM_2.5 is small enough to remain aloft and travel many hundreds …

Esipt-Enabled Alkyne Migration Provides Rapid Access To Benzoxazinones, Andrés G. Muñoz

Electronic Theses and Dissertations

Benozoxazinones have long been of interest to agrochemical scientists and medicinal chemists because of their widespread biological activity. These scaffolds are also of interest to synthetic chemists, who recognize the utility of benzoxazinones for accessing functionalized heterocycles. The use of efavirenz, a benzoxazinone-based reverse transcriptase inhibitor used in the treatment of HIV-1, has brought increased attention to this privileged pharmacophore. While there exist numerous strategies for synthesizing benzoxazinones, methods that do not require the use of acutely toxic and environmentally hazardous reagents are lacking. Consequently, there is a need to develop new methods for constructing this valuable scaffold. Herein, we …

Dynamics And Turnover Of Lipid And Protein Domains In Cells And Supported Bilayers, Alan Weisgerber

Electronic Theses and Dissertations

Protein and lipid clustering is an important mechanism for cell processes such as exo- and endo-cytosis and creating functional signaling complexes. It has been seen that both lipids and proteins are involved with the formation of cluster domains on cell membranes, yet little is known about the interplay between the two. In this work I began with visualizing lipid sorting to artificially induced curvature in supported lipid bilayers, with lipid tails affecting the sorting differently to curvature. These results demonstrate that lipids sort to curvature on curved, supported lipid bilayers. The sorting depends on the number of lipids in the …

Cooperative-Led Green Value Chain Development For Selected Highland Vegetables In Buguias, Benguet, Paul Kenneth B. Maghirang

Journal of Economics, Management and Agricultural Development

This study proposes a cooperative-led green value chain model for selected highland vegetables in Buguias, Benguet. Primary and secondary data were used in the study. Primary data were gathered through KII, FGD, and survey interviews among 30 farmer-members of LIFMPC. Descriptive, cost and returns, and value chain analysis were conducted. The proposed model of cooperative-led green value chain for selected highland vegetables was developed based on current practices of the farmer respondents. The greening opportunities were identified in different segments of the chain, from input sourcing to consumption, as well as the actors and their activities. Performing these green practices …

2022 Oakland Ca Data Summary, Gary Bishop

Fuel Efficiency Automobile Test Publications

Simple data summary for 2022 on-road vehicle emission measurements from Oakland CA.

Guide To The Dr. L.S. Dederick Papers, 1908-1956, Undated, Orson Kingsley, Patrick Koetsch

Archives & Special Collections Finding Aids

Louis Serle (L.S.) Dederick was born in Chicago in 1883. He received his Ph.D. in Mathematics from Harvard University in 1909. From 1909 – 1917 he was a professor at Princeton University. From 1917 – 1924 he was professor at the U.S. Naval Academy in Annapolis, Maryland. In 1926 Dederick began working for the U.S. Army, Ordnance. During his time there he was the Associate Director of the Ballistic Research Laboratory at the Aberdeen Proving Grounds in Aberdeen, Maryland where he focused on ballistics research.

While Dederick worked as a mathematician at the Aberdeen Proving Grounds, he was involved with …

Thin Liquid Films On A Rotary Bell Atomizer In Surface-Following Coordinates, Mark Doerre, Nelson Akafuah

Institute of Research for Technology Development Faculty Publications

This article analyzes a published formulation of the Navier–Stokes equations cast into surface-following coordinates and provides some additional mathematical background to follow the article. Ubiquitous in the paint shops of automotive plants around the world, a high-speed rotary bell is succinctly described as a rapidly spinning concave axisymmetric surface with liquid paint supplied from a port coinciding with the center of rotation. The spinning surface transfers momentum to the paint film causing it to flow outward. Upon reaching the bell periphery, it is flung off, subsequently forming an atomized spray transferred to an automotive body through advection and electrostatics. Common …

Protonation And Non-Innocent Ligand Behavior In Pyranopterin Dithiolene Molybdenum Complexes, Cassandra Gates, Haley Varnum, Catherine Getty, Natalie Loui, Ju Chen, Martin L. Kirk, Jing Yang, Sharon J. Nieter Burgmayer

Chemistry Faculty Research and Scholarship

The complex [TEA][Tp*MoIV(O)(S2BMOPP)] (1) [TEA = tetraethylammonium, Tp* = tris(3,5-dimethylpyrazolyl)hydroborate, and BMOPP = 6-(3-butynyl-2-methyl-2-ol)-2-pivaloyl pterin] is a structural analogue of the molybdenum cofactor common to all pyranopterin molybdenum enzymes because it possesses a pyranopterin-ene-1,2-dithiolate ligand (S2BMOPP) that exists primarily in the ring-closed pyrano structure as a resonance hybrid of ene-dithiolate and thione-thiolate forms. Compound 1, the protonated [Tp*MoIV(O)(S2BMOPP-H)] (1-H) and one-electron-oxidized [Tp*MoV(O)(S2BMOPP)] [1-Mo(5+)] species have been studied using a combination of electrochemistry, electronic absorption, and electron paramagnetic resonance (EPR) spectroscopy. Additional insight into the nature of these molecules has been derived from electronic structure computations. Differences in dithiolene C–S bond …

Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Improvement of nutrient use efficiency and limiting trace elements such as arsenic and uranium bioavailability is critical for sustainable agriculture and food safety. Arsenic and uranium possess different properties and mobility in soils, which complicates the effort to reduce their uptake by plants. Here, we postulate that unsaturated soil amended with ferrihydrite nanominerals leads to improved nutrient retention and helps reduce uptake of these geogenic contaminants. Unsaturated soil is primarily oxic and can provide a stable environment for ferrihydrite nanominerals. To demonstrate the utility of ferrihydrite soil amendment, maize was grown in an unsaturated agricultural soil that is known to …