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Articles 1441 - 1470 of 69093

Full-Text Articles in Physical Sciences and Mathematics

Computational Methods For Oi-Modules, Michael Morrow Jan 2024

Computational Methods For Oi-Modules, Michael Morrow

Theses and Dissertations--Mathematics

Computational commutative algebra has become an increasingly popular area of research. Central to the theory is the notion of a Gröbner basis, which may be thought of as a nonlinear generalization of Gaussian elimination. In 2019, Nagel and Römer introduced FI- and OI-modules over FI- and OI-algebras, which provide a framework for studying sequences of related modules defined over sequences of related polynomial rings. In particular, they laid the foundations of a theory of Gröbner bases for certain classes of OI-modules. In this dissertation we develop an OI-analog of Buchberger's algorithm in order to compute such Gröbner bases, as well …


Empowering Communities Through Education Creating The School Of Green, Kyle Martin Jan 2024

Empowering Communities Through Education Creating The School Of Green, Kyle Martin

Senior Honors Theses and Projects

The School of Green initiative aims to foster environmental stewardship through community-driven STEM education programs. This paper evaluates the initiative’s impact, critiques its planning, and strategizes for future success. It discusses the evolution of the School of Green Series, its community impact, and future directions. The paper also provides a contextual framework reflective analysis and outlines personal motivations and aspirations. Through meticulous documentation and archival research methods, this project aims to detail the significance of the School of Green Series in promoting environmental education and inclusivity. The comprehensive event report will not only analyze successes and areas for improvement but …


Chirality Determination Using Three-Wave Mixing Microwave Spectroscopy, Nicole Taylor Moon Jan 2024

Chirality Determination Using Three-Wave Mixing Microwave Spectroscopy, Nicole Taylor Moon

Doctoral Dissertations

"Rotational spectroscopy has established itself as a reliable gas-phase spectroscopic technique for the structural determination of molecules. This reliability has stemmed from both advancements in microwave technology and a willingness from the community to push the boundaries of the field. In this dissertation, the boundaries are tested in both how well the technique can determine the structure of molecules exhibiting large amplitude motion and through chirality determination. The first half of this dissertation explores the use of deep averaging to determine the structure of silicon containing molecules in collaboration with Dr. Guirgis from the College of Charleston. For each of …


The "Upside-Down" River: Trends In Total Nitrogen, Total Phosphorus, And Microcystin Concentration In The Klamath Basin, 2010-2021, Kayla M. Fitzpatrick Jan 2024

The "Upside-Down" River: Trends In Total Nitrogen, Total Phosphorus, And Microcystin Concentration In The Klamath Basin, 2010-2021, Kayla M. Fitzpatrick

Cal Poly Humboldt theses and projects

The Klamath River tends to experience impaired upstream water quality, which improves downstream. Although this consensus is accepted, an updated spatiotemporal analysis of certain water quality parameters has not been conducted since 2017. With four of the Klamath River’s dams slated for removal by the end of 2024, it is critical to have an updated assessment of current water quality conditions from which to compare conditions following dam removal. In this study, total nitrogen (TN), total phosphorus (TP), and microcystin data from 2010-2021 were analyzed to determine concentration trends from Link Dam to the Klamath River Estuary.

Concentrations of TN …


Basal Topography And Carbon Accumulation Rate Of A Rare Northern California Coastal Fen, Sarah Leidinger Jan 2024

Basal Topography And Carbon Accumulation Rate Of A Rare Northern California Coastal Fen, Sarah Leidinger

Cal Poly Humboldt theses and projects

Increasingly, the importance of peatlands as biodiversity hotpots, year-round water storage features, and significant carbon sinks are being recognized. Despite this, they are one of the most vulnerable ecosystems globally. While some peatland conservation and restoration initiatives are being developed, a greater understanding of small peatlands is needed to make management decisions. This study aims to determine the timing of peat formation, peat volume, and carbon accumulation rates of the Conspicuous Scoop Fen, a small (2.1-acre) fen near Bridgeville, California (~840 m.a.s.l.). During the summers of 2022 and 2023, I collected 39 m of peat cores at 14 sampling locations. …


Giving Workers The 'Green Light': Defining Green Jobs And Exploring Their Distribution In The Us, Cole Fuller Jan 2024

Giving Workers The 'Green Light': Defining Green Jobs And Exploring Their Distribution In The Us, Cole Fuller

Honors Theses and Capstones

As the United States continues to adopt sustainable practices and policies to combat climate change, it is important to consider how these green changes affect the workforce. The term ‘Green Jobs’ has become the colloquial term to refer to sustainable occupations, and despite its popularity in the literature, it often has different meanings in different settings. Our first goal was to explore these definitions and establish one to contextualize our research. We used data from the Occupational Information Network, and used their green job definition, which classifies jobs as green if, and how, they are impacted by the greening economy. …


Student Attitudes And Intentions To Use Continuous Authentication Methods Applied To Mitigate Impersonation Attacks During E-Assessments, Andrea E. Green Jan 2024

Student Attitudes And Intentions To Use Continuous Authentication Methods Applied To Mitigate Impersonation Attacks During E-Assessments, Andrea E. Green

CCE Theses and Dissertations

No solution can ultimately eliminate cheating in online courses. However, universities reserve funding for authentication systems to minimize the threat of cheating in online courses. Most higher education institutions use a combination of authentication methods to secure systems against impersonation attacks during online examinations. Authentication technologies ensure that an online course is protected from impersonation attacks. However, it is important that authentication methods secure systems against impersonation attacks with minimal disruption during an examination. Authentication methods applied to secure e-assessments against impersonation attacks may impact a student’s attitude and intentions to use the e-examination system.

In this regard, the research …


Slₖ-Tilings And Paths In ℤᵏ, Zachery T. Peterson Jan 2024

Slₖ-Tilings And Paths In ℤᵏ, Zachery T. Peterson

Theses and Dissertations--Mathematics

An SLₖ-frieze is a bi-infinite array of integers where adjacent entries satisfy a certain diamond rule. SL₂-friezes were introduced and studied by Conway and Coxeter. Later, these were generalized to infinite matrix-like structures called tilings as well as higher values of k. A recent paper by Short showed a bijection between bi-infinite paths of reduced rationals in the Farey graph and SL₂-tilings. We extend this result to higher k by constructing a bijection between SLₖ-tilings and certain pairs of bi-infinite strips of vectors in ℤᵏ called paths. The key ingredient in the proof is the relation to Plucker friezes and …


Understanding The Role Of Tacit And Explicit Knowledge Hiding In Organizations, Darren Wiggins Jan 2024

Understanding The Role Of Tacit And Explicit Knowledge Hiding In Organizations, Darren Wiggins

CCE Theses and Dissertations

Knowledge Hiding (KHi) is the deliberate act of withholding knowledge from others, driven by distrust. This distrust stems from three key factors: rationalized hiding, evasive hiding, and playing dumb. The latter two, evasive hiding and playing dumb, are particularly detrimental as they foster a cycle of mutual distrust within the workplace. To counteract this, organizations have significantly invested in promoting Tacit Knowledge (TK) and Explicit Knowledge (EK) sharing. These initiatives aimed to facilitate knowledge transfer, foster collaboration, enhance problem-solving capabilities, and strengthen social and interpersonal relationships.

Recent studies highlighted the importance of understanding the attributes linked to TK and EK. …


Empirical Assessment Of Remote Workers’ Cyberslacking And Computer Security Posture To Assess Organizational Cybersecurity Risks, Ariel Luna Jan 2024

Empirical Assessment Of Remote Workers’ Cyberslacking And Computer Security Posture To Assess Organizational Cybersecurity Risks, Ariel Luna

CCE Theses and Dissertations

No abstract provided.


A Bayesian Inversion For Emissions And Export Productivity Across The End-Cretaceous Boundary, Alexander A. Cox Jan 2024

A Bayesian Inversion For Emissions And Export Productivity Across The End-Cretaceous Boundary, Alexander A. Cox

Dartmouth College Master’s Theses

The end-Cretaceous mass extinction was marked by both the Chicxulub impact and the ongoing emplacement of the Deccan Traps flood basalt province. Both of these events perturbed the environment by the emission of climate-active volatiles, primarily CO2 and SO2. To understand the mechanism of extinction, we must disentangle the timing, duration, and intensity of volcanic and meteoritic environmental forcings. In this thesis, we used a parallel Markov chain Monte Carlo approach to invert for the aforementioned volatile emissions, export productivity, and remineralization from 67 to 65 million years ago using the LOSCAR (Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir) model. The parallel …


The Effects Of Temperature, Flooding, And Goose Feces Addition On Greenhouse Gas Emissions And Ammonification In Four High-Latitude Soils From Western Alaska, Jenna M. Ross Jan 2024

The Effects Of Temperature, Flooding, And Goose Feces Addition On Greenhouse Gas Emissions And Ammonification In Four High-Latitude Soils From Western Alaska, Jenna M. Ross

Electronic Theses and Dissertations

The large carbon (C) stock of wetlands is vulnerable to climate change, especially in high latitudes that are warming at a disproportional rate. Likewise, low-elevation Arctic coastal areas will flood more frequently under climate change and sea-level rise, which may alter goose herbivory and fecal deposition patterns if geese move inland. While temperature, flooding, and feces impact soil C emissions, their interactive effects have been rarely studied. Here, I explore the impact of these interactions on CO2 and CH4 emissions and nitrogen (N) mineralization (ammonification) in soils collected from four plant communities in the Yukon-Kuskokwim (Y-K) Delta, a high latitude …


Enhancing The Efficiency And Scalability Of Cloud Networking Systems, Jiaxin Lei Jan 2024

Enhancing The Efficiency And Scalability Of Cloud Networking Systems, Jiaxin Lei

Computer Science and Engineering Dissertations

Overlay networks are the de facto network virtualization technique for providing flexible and customized connectivity among distributed containers in the cloud. Despite their widespread adoption, overlay networks incur significant overhead due to their complexity, resulting in notable performance degradation compared to physical networks.

In this dissertation, I present our three-stage solutions aimed at addressing the challenges of efficiency and scalability in cloud-based container overlay networks: Firstly, we conduct a comprehensive empirical performance study of container overlay networks, identifying crucial parallelization bottlenecks within the kernel network stack. Our observations and root cause analysis uncover that these inefficiencies primarily arise from the …


Advancing Deep Learning With Graph-Based Structural Insights: From Graph Classification To Semantic Segmentation, Xin Ma Jan 2024

Advancing Deep Learning With Graph-Based Structural Insights: From Graph Classification To Semantic Segmentation, Xin Ma

Computer Science and Engineering Dissertations

Deep learning has profoundly transformed machine learning by offering sophisticated data representations, yet effectively incorporating structural information remains a challenge. Structural data, whether explicit or implicit, has the potential to significantly enhance the performance of deep learning tasks. This research investigates the benefits of structural information across three crucial tasks: classification, clustering, and segmentation. For explicit structural data, where inputs are directly represented as graphs, we investigate graph-level classification in brain connectivity networks. We introduce the Multi-resolution Edge Network (MENET), a novel framework designed to identify disease-specific connectomic benchmarks with high discriminatory power across diagnostic categories. MENET leverages graph-level representations …


Music Recommendation Using Exemplars And Contrastive Learning, Tina Tran Jan 2024

Music Recommendation Using Exemplars And Contrastive Learning, Tina Tran

Honors Undergraduate Theses

The popularity of AI audio applications is growing, it is used in chatbots, automated voice translation, virtual assistants, and text-to-speech translation. Audio classification is crucial in today’s world with a growing need to sort and classify millions of existing audio data with increasing amounts of new data uploaded over time. In the area of classification lies the difficult and lucrative problem of music recommendation. Research in music recommendation has trended over time towards collaborative-based approaches utilizing large amounts of user data. These approaches tend to deal with the cold-start problem of insufficient data and are costly to train. We look …


Development Of Vacuum-Assisted Headspace High-Capacity Solid-Phase Microextraction For The Determination Of Semi-Volatile Compounds From Samples At Lower Temperatures, Shannon L. Thomas, Kevin A. Schug, Colton Myers, Jason S. Herrington, Reagan L. Miller, Anush Pabley, Frank W. Foss Jan 2024

Development Of Vacuum-Assisted Headspace High-Capacity Solid-Phase Microextraction For The Determination Of Semi-Volatile Compounds From Samples At Lower Temperatures, Shannon L. Thomas, Kevin A. Schug, Colton Myers, Jason S. Herrington, Reagan L. Miller, Anush Pabley, Frank W. Foss

Chemistry & Biochemistry Dissertations

Vacuum-assisted headspace solid-phase microextraction (Vac-HS-SPME) is a method used to increase solid-phase microextraction sampling of semi-volatile organic compounds. Three studies were conducted using Vac-HS-SPME via gas chromatography - mass spectrometry (GC-MS) methods for analysis of various sample types. First, a study was performed using Vac- HS-SPME combined with a high-capacity (HC) SPME Arrow to determine the operational fundamentals and workflow necessary to achieve optimal extraction of semi-volatile compounds from a model solid matrix (Ottawa sand). The fundamentals investigated included the seals necessary to create a leak-free sampling vial under vacuum conditions; the magnitude of the vacuum exerted, and the time …


Towards Machine Learning-Based Control Of Autonomous Vehicles In Solar Panel Cleaning Systems, Farima Hajiahmadi Jan 2024

Towards Machine Learning-Based Control Of Autonomous Vehicles In Solar Panel Cleaning Systems, Farima Hajiahmadi

Theses and Dissertations

This thesis presents a machine learning (ML)-based approach for the intelligent control of Autonomous Vehicles (AVs) utilized in solar panel cleaning systems, aiming to mitigate challenges arising from uncertainties, disturbances, and dynamic environments. Solar panels, predominantly situated in dedicated lands for solar energy production (e.g., agricultural solar farms), are susceptible to dust and debris accumulation, leading to diminished energy absorption. Instead of labor-intensive manual cleaning, robotic cleaners offer a viable solution. AVs equipped to transport and precisely position these cleaning robots are indispensable for efficient navigation among solar panel arrays. However, environmental obstacles (e.g., rough terrain), variations in solar panel …


Solution Combustion Synthesis And Characterization Of Fumarolic Mineral Dolerophanite, Copper (Ii) Oxide Sulfate, Eric J. Cyganowski Jan 2024

Solution Combustion Synthesis And Characterization Of Fumarolic Mineral Dolerophanite, Copper (Ii) Oxide Sulfate, Eric J. Cyganowski

Chemistry & Biochemistry Theses

Dolerophanite Cu2OSO4 is a rare mineral found almost exclusively in the fumaroles of volcano systems and is sensitive to temperature and humidity conditions. It has a monoclinic C2/m crystal structure characterized by two-dimensional layers composed of sulfate anions dispersed amongst copper (II) oxide backbones. There has been recent interest in dolerophanite due to the magnetic properties of its Kagome-like lattice as well as its potential use as a photocatalyst or Li-ion battery electrode. Literature on the material however has been limited by the available synthesis strategies. As such, this thesis work presents a novel strategy …


Synthesis Of Hydroxycinnamate Derivatives And Characterization Of Bioactivity As Radical Scavengers And Α-Glucosidase Inhibitors, Cate Simmermaker Jan 2024

Synthesis Of Hydroxycinnamate Derivatives And Characterization Of Bioactivity As Radical Scavengers And Α-Glucosidase Inhibitors, Cate Simmermaker

University of the Pacific Theses and Dissertations

Hydroxycinnamic acids (HCAs), a class of polyphenols commonly found in regularly consumed fruits and vegetables, have been investigated for efficacy as radical scavengers and glycosidase inhibitors. These compounds could mitigate the negative health effects of free radicals in oxidative stress diseases including neurodegeneration, cancer and diabetes. The HCAs investigated were caffeic acid (1), p-coumaric acid (2), ferulic acid (3), and sinapic acid (4). The compounds were derivatized with synthetically prepared amino acid esters through a four-step synthesis including protective acetylation, chlorination of the carboxylic acid, amidation, and subsequent deprotection of all applied protecting groups. The inclusion of diverse derivative groups …


Hybridization Kinetics Of Four-Way Junctions Localized On A Dna Scaffold, Katherine N. Taylor Jan 2024

Hybridization Kinetics Of Four-Way Junctions Localized On A Dna Scaffold, Katherine N. Taylor

Honors Undergraduate Theses

DNA computing is an ever-growing field with scientists trying to design structures that optimize logic gate communication to develop fast, biologically compatible, computational structures. We hypothesize that by using the principles of DNA computing, it is possible to design a DNA tile capable of studying localized DNA hybridization that can differentiate between oligonucleotides of different structural conformations. This includes synthetically manipulating DNA into a nanostructure that can perform Boolean logic functions to calculate the different rates of hybridization. To test our hypothesis, we designed a DNA Tile that incorporated a 4WJ using YES logic. Linear and hairpin single-stranded (ss) DNA …


Multicolor Bipartite Ramsey Number Of Double Stars, Gregory M. Decamillis Jan 2024

Multicolor Bipartite Ramsey Number Of Double Stars, Gregory M. Decamillis

Honors Undergraduate Theses

The core idea of Ramsey theory is that complete disorder is impossible. Given a large structure, no matter how complex it is, we can always find a smaller substructure that has some sort of order. For positive integers $n, m$, the double star $S(n,m)$ is the graph consisting of the disjoint union of two stars $K_{1,n}$ and $K_{1,m}$ together with an edge joining their centers. The $k$-color bipartite Ramsey number of $ S(n,m)$, denoted by $r_{bip}(S(n,m);k)$, is the smallest integer $N$ such that, in any $k$-coloring of the edges of the complete bipartite graph $K_{N,N}$, there is a monochromatic copy …


Searching For Black Holes In The Galactic Center, Caden Zaccardi Jan 2024

Searching For Black Holes In The Galactic Center, Caden Zaccardi

Honors Undergraduate Theses

Due to the high extinction along the plane of the Milky Way towards the Galactic Center (GC), it is useful to look at objects that are bright in the near-infrared (near-IR) to obtain data with Earth-based instruments. To identify X-ray Binary (XRB) counterparts towards the GC, we used near-IR spectra from the Large Binocular Telescope (LBT). After reducing the LUCI/LBT spectra with the superFATBOY (sFB) pipeline, we compared our near-IR spectra to previously matched IR and X-ray sources in the GC (DeWitt, 2011). Particularly, we looked for H and He emission lines, which indicate signs of a hard radiation field …


Frieze And Tiling Groups In The Lorentz-Minkowski Plane, Michael O. Lynch Jan 2024

Frieze And Tiling Groups In The Lorentz-Minkowski Plane, Michael O. Lynch

Honors Undergraduate Theses

In this thesis, there is a presentation of the isometries from the Lorentz-Minkowski Plane and a solution to the Frieze Patterns. There is a suggestion for a solution for the Tiling Patterns. Since the construction of these mathematical structures is well understood in the Euclidean plane, one can follow a similar approach to the construction of such objects to find the unique number of groups that describe all possible frieze patterns while there is a suggestion of the number for the tiling case. There is a reflection of these results in a computational and cosmological context.


Implementation Of Prognosticator Algorithm For Initiation Of Serious Illness Discussions And Improving The Rate Of Palliative And Hospice Referrals, Joy Isebor Jan 2024

Implementation Of Prognosticator Algorithm For Initiation Of Serious Illness Discussions And Improving The Rate Of Palliative And Hospice Referrals, Joy Isebor

Doctor of Nursing Practice (DNP) Scholarly Projects

Context: Early serious illness conversations related to end-of-life and goals of care with seriously ill patients have been associated with improving patients' outcomes and quality of care (Bernacki et al., 2015). However, initiating these serious illness discussions has been challenging in the home-based primary care setting.

Objectives: To train and support home-based primary care clinicians in integrating best practices in serious illness discussions and decision-making engagement among patients sixty-five and older with serious illnesses, optimize the alignment between patient goals and the medical care they receive, improving their quality of life and the rate of palliative care and hospice referrals. …


Higher-Derivative Quantum Field Theory And Its Implications For Hawking Radiation And Nonlocality, Gordon Kanan Jan 2024

Higher-Derivative Quantum Field Theory And Its Implications For Hawking Radiation And Nonlocality, Gordon Kanan

Physics Dissertations

One of the fundamental equations of quantum field theory is the Klein-Gordon equation which can be constructed using irreducible representations of the Poincar ́e group and describes the dynamics of spin-0 matter. The higher derivative Klein- Gordon equations are also constructed using irreducible representations of the Poincar ́e group and are, thus, invariant under operations of this group. These higher derivative Klein-Gordon equations can be placed into two series depending on the power of the derivative, one for odd powers of the derivative and one for even powers, whose solu- tions yield timelike and spacelike fields. Applying these higher derivative …


Respiratory-Motion Matched Attenuation Correction For Dual-Gated Cardiac Single Photon Emission Computed Tomography (Spect), Christina Xing Jan 2024

Respiratory-Motion Matched Attenuation Correction For Dual-Gated Cardiac Single Photon Emission Computed Tomography (Spect), Christina Xing

Physics Theses

Cardiac and respiratory dual-gated single-photon emission computed tomography (SPECT) is a promising technique for minimizing the motion artifacts in myocardial perfusion imaging (MPI). However, attenuation correction (AC) for dual-gated SPECT using an attenuation map averaged over the respiratory cycle may lead to mismatched attenuation correction artifacts. In this study, we propose a respiratory motion-matched attenuation correction (RMM-AC) to further improve dual-gated SPECT. For each respiratory gate, RMM-AC uses an attenuation map that matches the SPECT image in a 4D reconstruction framework. Filtered backprojection reconstruction without AC (FBP-nAC) and 4D reconstruction with the attenuation map averaged over all respiratory gates (AVE-AC) …


Synthesis Of Cu-Cy Nanoparticles For Treating Pfas In Water, Ligang Wang Jan 2024

Synthesis Of Cu-Cy Nanoparticles For Treating Pfas In Water, Ligang Wang

Physics Theses

This work aims to address the cumulative harm caused by perfluoroalkyl and polyfluoroalkyl substances (PFAS) in water to human health and the ecological environment around the world. Reducing or removing PFAS pollution is an urgent need. Cu-Cy nanoparticles are photosensitizers, which were developed for photodynamic therapy of cancer in the first place. In this work, we use Cu-Cy for the catalytic degradation of PFAS. Synthesis of Cu-Cy nanoparticles in deionized water at 90 degrees Celsius is a low-cost and efficient method. We demonstrated the detailed process of synthesizing Cu-Cy nanoparticles. Under ultraviolet illumination, the synthesized Cu-Cy nanoparticles turned yellow as …


Flexible Attenuation Fields: Tomographic Reconstruction From Heterogeneous Datasets, Clifford S. Parker Jan 2024

Flexible Attenuation Fields: Tomographic Reconstruction From Heterogeneous Datasets, Clifford S. Parker

Theses and Dissertations--Computer Science

Traditional reconstruction methods for X-ray computed tomography (CT) are highly constrained in the variety of input datasets they admit. Many of the imaging settings -- the incident energy, field-of-view, effective resolution -- remain fixed across projection images, and the only real variance is in the detector's position and orientation with respect to the scene. In contrast, methods for 3D reconstruction of natural scenes are extremely flexible to the geometric and photometric properties of the input datasets, readily accepting and benefiting from images captured under varying lighting conditions, with different cameras, and at disparate points in time and space. Extending CT …


Self-Exciting Point Processes In Real Estate, Ian Fraser Jan 2024

Self-Exciting Point Processes In Real Estate, Ian Fraser

Theses and Dissertations (Comprehensive)

This thesis introduces a novel approach to analyzing residential property sales through the lens of stochastic processes by employing point processes. Herein, property sales are treated as point patterns, using self-exciting point process models and a variety of statistical tools to uncover underlying patterns in the data. Key findings include the identification and explanation of clustering in both space and time, and the efficacy of a temporal Hawkes process with a sinusoidal background in predicting home sale occurrences. The temporal analysis starts by employing the state of art techniques for time series data like regression, autoregressive, and autoregressive integrated moving …


Recoloring In Hereditary Graph Classes: Structure And Decomposition, Manoj Belavadi Jan 2024

Recoloring In Hereditary Graph Classes: Structure And Decomposition, Manoj Belavadi

Theses and Dissertations (Comprehensive)

In this thesis we study reconfiguration problems in graph theory. A reconfiguration problem is generally defined on the solution space of a problem for which a configuration can be defined as a feasible solution, for example, a coloring of a graph. In Chapters 1 through 4 we study the reconfiguration of vertex colorings. The reconfiguration graph of the k-colorings, denoted Rk(G), is the graph whose vertices are the k-colorings of G and two colorings are adjacent in Rk(G) if they differ on exactly one vertex. The basic question investigated here …