Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 2611 - 2640 of 302419

Full-Text Articles in Physical Sciences and Mathematics

Thz Radar Observations Of Hydrometeors In A Spray Chamber, Zeen Zhu, Fan Yang, Edward Luke, Elise Rosky, Katia Lamer, Pavlos Kollias Jun 2024

Thz Radar Observations Of Hydrometeors In A Spray Chamber, Zeen Zhu, Fan Yang, Edward Luke, Elise Rosky, Katia Lamer, Pavlos Kollias

Michigan Tech Publications, Part 2

A THz radar, with its wide bandwidth, is capable of high-resolution imaging down to the centimeter scale. In this study, a THz radar is applied to detect hydrometeors generated in a spray chamber. The observed backscattering signals show fluctuations at centimeter scales, indicating various hydrometeor distribution patterns along the radar beam. A co-located High-Speed Imaging (HSI) sensor is used to measure the Drop Size Distributions (DSD) in the spray chamber. The radar sampling beam is well aligned with the HSI probes, allowing an objective comparison between the remote sensing and in situ observations. In this study, the observed radar power …


Procedural Pre-Training For Visual Recognition, Connor S. Anderson Jun 2024

Procedural Pre-Training For Visual Recognition, Connor S. Anderson

Theses and Dissertations

Deep learning models can perform many tasks very capably, provided they are trained correctly. Usually, this requires a large amount of data. Pre-training refers to a process of creating a strong initial model by first training it on a large-scale dataset. Such a model can then be adapted to many different tasks, while only requiring a comparatively small amount of task-specific training data. Pre-training is the standard approach in most computer vision scenarios, but it's not without drawbacks. Aside from the cost and effort involved in collecting large pre-training datasets, such data may also contain unwanted biases, violations of privacy, …


Zeros Of Convex Combinations Of Elementary Families Of Harmonic Functions, Rebekah Ottinger Jun 2024

Zeros Of Convex Combinations Of Elementary Families Of Harmonic Functions, Rebekah Ottinger

Theses and Dissertations

Brilleslyper et al. analyzed a one-parameter family of harmonic trinomials, and Brooks and Lee analyzed a one-parameter family of harmonic functions with poles. Each family was explored to find the relationship between the size of the parameter and the number of zeros of the harmonic function. In this thesis, we examine convex combinations of members of these families. We determine conditions under which the critical curves separating the sense-preserving and sense-reversing regions are circular. We show that the number of zeros of a convex combination can be greater than the maximum number of zeros of either part.


Development Of Cyber Security Platform For Experiential Learning, Abhishek Vaish, Ravindra Kumar, Samo Bobek, Simona Sternad Jun 2024

Development Of Cyber Security Platform For Experiential Learning, Abhishek Vaish, Ravindra Kumar, Samo Bobek, Simona Sternad

Journal of Cybersecurity Education, Research and Practice

The cyber security education market has grown-up exponentially, with a CAGR of 13.9 % as reported by Data Intelo. The report published by the World Economic Fo- rum 2023 indicates a shortfall of 2.27 million cyber security experts in 2021 across different roles and hence manifest that Skill-based cyber security education is the need of the hour. Cybersecurity as a field has evolved as a multi-discipline, multi-stakeholder and multi-role discipline. Therefore, the need to address formal education with an outcome-based philosophy is imperative to address for a wider audience with varied past training in their formal education. With the Internet …


Bring Them Back To Campus: Optional Engaging Campus Activities For Online Classes With Livestreaming, Victoria Brown Ed. D., David Devraj Kumar Jun 2024

Bring Them Back To Campus: Optional Engaging Campus Activities For Online Classes With Livestreaming, Victoria Brown Ed. D., David Devraj Kumar

FDLA Journal

Ever since the pandemic, students have adapted to taking their classes online. However, coming to campus promotes a connection to the university through faculty and classmates. The event had a dual purpose in promoting the adoption of computational skills through robots in K-12 classrooms, which is the educational goal of the project. A carefully designed “Educational Robotics Day” event encourages students to return to campus through an engaging event while accommodating those students that are unable to come to the campus but still attend. The coordinators of the event also measured the effectiveness of the event through an exit survey …


Investigating H2s Occurrence In Bakken Oil-Producing Wells Using Sulfur Isotopes In Gas, Water, And Rock Samples, Alexander V. Chakhmakhchev, Marc D. Kurz, T. Austin Mcrae, Xue Yu, Arash Abarghani, Darren D. Schmidt, Nicholas A. Azzolina, Bethany A. Kurz, James A. Sorensen Jun 2024

Investigating H2s Occurrence In Bakken Oil-Producing Wells Using Sulfur Isotopes In Gas, Water, And Rock Samples, Alexander V. Chakhmakhchev, Marc D. Kurz, T. Austin Mcrae, Xue Yu, Arash Abarghani, Darren D. Schmidt, Nicholas A. Azzolina, Bethany A. Kurz, James A. Sorensen

EERC Publications

This work investigated multiple mechanisms that can potentially lead to H2S in the oil production stream of Bakken wells, including TSR, BSR, source rock generation, migration from deeper or shallower formations that contain H2S, and geomechanical mechanisms related to reservoir stimulation work.


Field Implementation And Surveillance Of Gas Injection Enhanced Oil Recovery In The Bakken, Jin Zhao, Lu Jin, Nicholas A. Azzolina, Xincheng Wan, Steven A. Smith, Nicholas W. Bosshart, James A. Sorensen Jun 2024

Field Implementation And Surveillance Of Gas Injection Enhanced Oil Recovery In The Bakken, Jin Zhao, Lu Jin, Nicholas A. Azzolina, Xincheng Wan, Steven A. Smith, Nicholas W. Bosshart, James A. Sorensen

EERC Publications

A series of activities were performed in this study to explore real-time visualization, forecasting, and control methods for improved reservoir surveillance during EOR processes.


Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Draft Final Revised Residential Metals Abatement Program (Rmap) Quality Assurance Project Plan (Qapp) (Residential Parcels) (Dated June 7, 2024), Molly Roby Jun 2024

Re: Approval Letter For The Butte Priority Soils Operable Unit (Bpsou) Draft Final Revised Residential Metals Abatement Program (Rmap) Quality Assurance Project Plan (Qapp) (Residential Parcels) (Dated June 7, 2024), Molly Roby

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.


Hardware Acceleration Of Numerical Methods For Solving Ordinary Differential Equations, Soham Bhattacharya Jun 2024

Hardware Acceleration Of Numerical Methods For Solving Ordinary Differential Equations, Soham Bhattacharya

Theses and Dissertations

Along with the advancement in technology, the role of hardware accelerators is increasing consistently, delivering advancements in scientific simulations and data analysis in scientific computing, signal processing tasks in communication systems, matrix operations, and neural network computations in artificial intelligence and machine learning models. On the other hand, several high-speed computer applications in this era of high-performance computing often depend on ordinary differential equations (ODEs); however, their nonlinear nature can present a challenge to obtaining analytic solutions. Consequently, numerical approaches prove effective in delivering only approximate solutions to these equations. This research discusses the implementation of a customized hardware accelerator …


Proceedings Of The Cuny Games Conference 10.0, Robert O. Duncan, Grace Axler-Diperte, Joe Bisz, Christina Boyle, Devorah Kletenik, Carolyn Stallard Jun 2024

Proceedings Of The Cuny Games Conference 10.0, Robert O. Duncan, Grace Axler-Diperte, Joe Bisz, Christina Boyle, Devorah Kletenik, Carolyn Stallard

Publications and Research

The ten-year anniversary (!) of the CUNY Games Conference combines workshops, idea exchanges, interactive participant presentations, playtesting, and playing tabletop games into a two-day hybrid event to promote and discuss game-based learning. The conference focuses on creative pedagogy, such as playful learning activities or games, that teachers can use in the classroom every day. Day 1 featured interactive presentations by attendees, informal idea exchange sessions, and workshops by the conference organizers. Day 2 featured select presentations and workshops, poster sessions, playtesting and game modding, and casual play of tabletop games.


Cellular Automata Modeling Approach Of Addiction, Ruba Hameed Jun 2024

Cellular Automata Modeling Approach Of Addiction, Ruba Hameed

Thesis/ Dissertation Defenses

This thesis develops a mathematical model and cellular automata simulations to study the spread of drug addiction in populations, incorporating key factors like peer influence, substance availability, support networks, and awareness campaigns. The model describes transitions between non-use, experimental use, recreational use, and addiction states. Mathematical analysis establishes model properties, while an irregular graph cellular automata framework analyzes emerging spatial patterns and behaviors. Extensive scenario simulations explore peer influence, isolation, substance availability, support networks, and awareness campaign impacts, enabling visualization of model evolution over time and determining thresholds, tipping points, and intervention effectiveness. The findings provide an actionable understanding of …


Evaluation Of Inner Products Of Implicitly Defined Finite Element Functions On Multiply Connected Planar Mesh Cells, Jeffrey S. Ovall, Samuel E. Reynolds Jun 2024

Evaluation Of Inner Products Of Implicitly Defined Finite Element Functions On Multiply Connected Planar Mesh Cells, Jeffrey S. Ovall, Samuel E. Reynolds

Mathematics and Statistics Faculty Publications and Presentations

In recent years, there has been significant interest in the development of finite element methods defined on meshes that include rather general polytopes and curvilinear polygons. In the present work, we provide tools necessary to employ multiply connected mesh cells in planar domains, i.e., cells with holes, in finite element computations. Our focus is efficient evaluation of the 𝐻1𝐻1 semi-inner product and 𝐿2𝐿2 inner product of implicitly defined finite element functions of the types arising in boundary element based finite element methods and virtual element methods. Such functions are defined as solutions of Poisson problems having a polynomial source term …


Scaling Expertise: A Note On Homophily In Online Discourse And Content Moderation, Dylan Weber Jun 2024

Scaling Expertise: A Note On Homophily In Online Discourse And Content Moderation, Dylan Weber

New England Journal of Public Policy

It is now empirically clear that the structure of online discourse tends toward homophily; users strongly prefer to interact with content and other users that are similar to them. I review the evidence for the ubiquity of homophily in discourse and highlight some of its worst effects including narrowed information landscape for users and increased spread of misinformation. I then discuss the current state of moderation frameworks at large social media platforms and how they are ill-equipped to deal with structural trends in discourse such as homophily. Finally, I sketch a moderation framework based on a principal of “scaling expertise” …


Microplastic Pollution In Stormwater: Preliminary Findings From The Oregon Coast, Jazmine Compton Jun 2024

Microplastic Pollution In Stormwater: Preliminary Findings From The Oregon Coast, Jazmine Compton

University Honors Theses

Microplastics have become ubiquitous in marine environments and pose a risk to ecosystem, organismal, and human health. Stormwater runoff has been suggested to be a major contributor to marine microplastic pollution. This project aims to quantify the average concentration of microplastics in stormwater in a community on the Oregon Coast. To accomplish this, stormwater samples were collected from five sites in Cannon Beach, Oregon, and one sample was analyzed using a dissection microscope. Using this technique, the number, size, and composition of the microplastic particles were determined. The calculated concentration of microplastics in the stormwater sample was 12.21 MPs/L, and …


Henna Chatbot Capstone Review, Kobe Norcross Jun 2024

Henna Chatbot Capstone Review, Kobe Norcross

University Honors Theses

This thesis reviews the development of the Henna Chatbot, an AI-powered DEI consultant designed to provide personalized feedback to organizations. Sponsored by DEI consultant Arsh Haque, the project aims to address gaps in current DEI software, which often lacks team-specific feedback. The Henna Chatbot leverages GPT-3.5 Turbo to create an affordable SaaS platform where organizations can train Henna with their DEI values, and Henna will help organizations stay aligned with those values. The project spanned twenty weeks and was completed by a team of eight computer science students at Portland State University. The development process followed Agile methodologies, emphasizing effective …


Examining The Interaction Between Calcium Supplement Use, Demographics, And Lifestyle Factors On Bone Health In Women, Vix Talbot Jun 2024

Examining The Interaction Between Calcium Supplement Use, Demographics, And Lifestyle Factors On Bone Health In Women, Vix Talbot

University Honors Theses

Osteoporosis is a condition which poses a significant health threat, particularly among women during the menopause transition, where accelerated bone loss increases fracture risk. Calcium supplementation has been shown to be an important intervention to mitigate bone mineral density (BMD) decline during this and other periods of life. However, the efficacy of calcium supplementation is influenced by various individual factors, including demographics and lifestyle habits. This study investigates the interaction between calcium supplement use, and several interaction terms on bone health in women. Multiple linear regression analysis is employed to assess the impact of these factors on BMD. Data from …


Student Perceptions: How Stem Students Value Belonging Interventions, Elizabeth Runkel Baez Jun 2024

Student Perceptions: How Stem Students Value Belonging Interventions, Elizabeth Runkel Baez

University Honors Theses

With the prioritization of increasing Science, Technology, Engineering, and Mathematics (STEM) graduates in the United States, researchers have become increasingly interested in how to promote STEM students' sense of belonging. Sense of belonging is considered a marker of persistence in STEM. Facilitated 'belonging interventions' are one way to strengthen a sense of belonging amongst STEM students. How students respond to, value, and understand these belonging interventions is relatively understudied. In this study, focus groups were conducted with STEM students from a single university to investigate how they value an in-class belonging activity. Qualitative thematic coding of focus group responses revealed …


Climate Justice Issues, Urban Heat Island Effect, And Trees As The Solution In Portland, Oregon, Cleo Needham Jun 2024

Climate Justice Issues, Urban Heat Island Effect, And Trees As The Solution In Portland, Oregon, Cleo Needham

University Honors Theses

Portland, Oregon, is experiencing rising temperatures caused by climate change and urban heat island effect. High heat disproportionately impacts vulnerable communities in Portland, causing harm to physical and mental health. Trees are a solution that reduces temperatures in urban environments. A strategy called 3-30-300 helps create a structure for where to place trees to help people receive the benefits. There are challenges with trees, such as the space required, the significant cost, and the time it takes to mature. Using trees as a solution can support and protect vulnerable communities in Portland, Oregon.


Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez Jun 2024

Spin And Charge Transport In Metallic Ferrimagnets And Disordered Magnetic Oxides, Leopoldo A. Hernandez

Electronic Theses and Dissertations

Recent efforts have been exploring the use of thin film synthetic ferrimagnets and disordered magnetic oxides for applications in spintronic devices. Due to the antiferromagnetic exchange interaction, ferrimagnetic materials offer the ultrafast dynamics of the antiferromagnetic exchange, with a net magnetization that can be influenced externally. With two, or more, competing ferromagnet sublattices, interesting properties arise that depend on the final magnetic landscape after growth of the material and it’s inherent magnetic anisotropy energies. Properties such as magnetic compensation temperatures, and perpendicular magnetic anisotropy are attractive for applications in spintronic memory and logic devices, some already being implemented in MRAM …


Building Blocks For W-Algebras Of Classical Types, Vladimir Kovalchuk Jun 2024

Building Blocks For W-Algebras Of Classical Types, Vladimir Kovalchuk

Electronic Theses and Dissertations

The universal 2-parameter vertex algebra W of type W(2, 3, 4; . . . ) serves as a classifying object for vertex algebras of type W(2, 3, . . . ,N) for some N in the sense that under mild hypothesis, all such vertex algebras arise as quotients of W. There is an ℕ X ℕ family of such 1-parameter vertex algebras known as Y-algebras. They were introduced by Gaiotto and Rapčák are expected to be building blocks for all W-algebras in type A, i.e, every W-(super) algebra in …


Differential Elliptic Flow Analysis Of Hadrons With Different Wuark Content In Simulated Pp Collisions, Elhussein Osama Jun 2024

Differential Elliptic Flow Analysis Of Hadrons With Different Wuark Content In Simulated Pp Collisions, Elhussein Osama

Theses and Dissertations

According to current physics theories, it is assumed that in the first microsecond after the big bang, the universe was in a state of matter called Quark-Gluon Plasma (QGP), where the fundamental consistent of matters (quarks and leptons), were highly energetic, and floating around freely. Searching for such phase of matter; as the possible earliest signatures after the big bang, and among many other interesting experimental measurements, the jet quenching and elliptic flow are the most important ones, in the heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) experiments.

The azimuthal anisotropy …


Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy Jun 2024

Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy

Electronic Theses and Dissertations

Total Knee Arthroplasty (TKA) is a widely performed surgical procedure aimed at alleviating pain and restoring function in patients with severe knee osteoarthritis. Despite its general success, disparities in postoperative outcomes have been observed across different racial and ethnic groups, with minority populations often experiencing less favorable results. One potential avenue for improving the generalizability of orthopaedic implants is using Statistical Shape and Intensity Models (SSIMs), which can be used to incorporate patient variability directly into the orthopaedic medical device development workflow through population-based finite element analysis.

This work aimed to construct an SSIM from a diverse subject set, incorporating …


Near-Surface Thermodynamic Influences On Evaporation Duct Shape, Sarah E. Wessinger, Daniel P. Greenway, Tracy Haack, Erin E. Hackett Jun 2024

Near-Surface Thermodynamic Influences On Evaporation Duct Shape, Sarah E. Wessinger, Daniel P. Greenway, Tracy Haack, Erin E. Hackett

Marine Science

This study utilizes in situ measurements and numerical weather prediction forecasts curated during the Coupled Air–Sea Processes Electromagnetic Ducting Research (CASPER) east field campaign to assess how thermodynamic properties in the marine atmospheric surface layer influence evaporation duct shape independent of duct height. More specifically, we investigate evaporation duct shape through a duct shape parameter, a parameter known to affect the propagation of X-band radar signals and is directly related to the curvature of the duct. Relationships between this duct shape parameter and air sea temperature difference (ASTD) reveal that during unstable periods (ASTD < 0), the duct shape parameter is generally larger than in near-neutral or stable atmospheric conditions, indicating tighter curvature of the M-profile. Furthermore, for any specific duct height, a strong linear relationship between the near-surface-specific humidity gradient and the duct shape parameter is found, suggesting that it is primarily driven by near-surface humidity gradients. The results demonstrate that an a priori estimate of duct shape, for a given duct height, is possible if the near-surface humidity gradient is known.

This article was published Open Access …


Combinatorial Problems On The Integers: Colorings, Games, And Permutations, Collier Gaiser Jun 2024

Combinatorial Problems On The Integers: Colorings, Games, And Permutations, Collier Gaiser

Electronic Theses and Dissertations

This dissertation consists of several combinatorial problems on the integers. These problems fit inside the areas of extremal combinatorics and enumerative combinatorics.

We first study monochromatic solutions to equations when integers are colored with finitely many colors in Chapter 2. By looking at subsets of {1, 2, . . . , n} whose least common multiple is small, we improved a result of Brown and Rödl on the smallest integer n such that every 2-coloring of {1, 2, . . . , n} has a monochromatic solution to equations with unit fractions. Using a recent result of Boza, …


Trust, Transparency, And Transport: The Impact Of Privacy Protection On The Acceptance Of Last-Mile Drone Delivery, Jurgen Heinz Famula Jun 2024

Trust, Transparency, And Transport: The Impact Of Privacy Protection On The Acceptance Of Last-Mile Drone Delivery, Jurgen Heinz Famula

Electronic Theses and Dissertations

A common set of problems commercial delivery companies face is finding ways to increase the efficiency and reliability of the “last mile” of a package’s journey, all while reducing operating costs. This need for efficiency has driven many companies to explore using unmanned aerial vehicles (UAVs), or drones, to get packages to their final destination. Although UAVs have great potential to help increase efficiency in commercial package delivery, this comes at a potential cost to the privacy of people who intersect the flight paths of these unmanned vehicles. This thesis explores the effect of a mobile phone application for commercial …


Capturing Latent Abilities And Latent Capacities Of Professional Golfers Using Nonlinear Mixed Effects Growth Modeling, Mac Wetherbee Jun 2024

Capturing Latent Abilities And Latent Capacities Of Professional Golfers Using Nonlinear Mixed Effects Growth Modeling, Mac Wetherbee

Electronic Theses and Dissertations

This study demonstrates an effective and innovative approach to measuring the latent athletic abilities and capacities of professional golfers. I used nonlinear mixed effects growth modeling (e.g., Dynamic Measurement Modeling) to measure professional golfers’ ability levels and capacities for improvement. I accomplished this using a two-stage modeling approach. First, a crossed linear mixed effects model estimated each player’s ability level in each year. In the second stage, I used the results from the first stage to estimate several candidate nonlinear growth trajectories for players’ abilities over time. The quadratic growth trajectory was the best-fitting of these trajectories and was used …


Bridging The Geometric And Quantum Information Of Structured Light, Andrew Alexander Voitiv Jun 2024

Bridging The Geometric And Quantum Information Of Structured Light, Andrew Alexander Voitiv

Electronic Theses and Dissertations

In this Dissertation, we review the several advances we have developed for preparing and measuring the geometric and quantum information of structured light. The geometric phase acts as a memory of transformations undertaken by physical processes; quantum entanglement underpins quantum information science which explores the theoretical and technological applications of nonclassical correlations. Beginning with classical light, we demonstrate novel experiments and measurements of geometric phase that are enabled by spatially structuring laser beams. We then extend those concepts to complement the richer possibilities within quantum optics. Our work covers new abilities in tailoring and measuring the phase content of spatially-structured …


Establishment Of A Research Site At The Kennedy Mountain Campus For The Observation Of Airborne Particulate Matter, Alyssa Knaus Jun 2024

Establishment Of A Research Site At The Kennedy Mountain Campus For The Observation Of Airborne Particulate Matter, Alyssa Knaus

Undergraduate Theses, Capstones, and Recitals

This thesis explored particulate matter (PM) concentrations at two sites within the Colorado Front Range. The study utilized two models of PurpleAir PM sensors, Flex and SD-II, to provide real-time, accessible data on PM1, PM2.5, and PM10 mass concentrations with the goal of establishing the first research site at the Kennedy Mountain Campus (KMC). The first of the two sites used during this study was at a suburban location outside of Denver, CO. This period was used as an instrument intercomparison period in order to conduct instrument analysis. The initial findings from this period found significant correlations between PM concentration …


Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke Jun 2024

Evaluating The Efficiency Of Low-Cost Air Quality Sensors At A Suburban Field Site, Olivia Wuttke

Undergraduate Theses, Capstones, and Recitals

Science surrounding the use of low-cost sensors (LCS) to monitor air quality is rapidly expanding to satisfy the need to fill in regional air quality data gaps. This project evaluated the suitability of two types of LCS: Modulair-PM and PurpleAir (SD and Flex models) as efficient means to measure airborne particulate matter. The study involved physical installation of nine co-located sensors at a suburban site in Denver, connectivity troubleshooting as necessary, and data analysis/modeling of data over multiple months (19 weeks). PM data was compared between individual sensors of the same type, as well as across the two different sensor …


Technology And Homelessness: How Website Design And Blockchain Technology Could Impact The Unhoused, Casey Pratt Jun 2024

Technology And Homelessness: How Website Design And Blockchain Technology Could Impact The Unhoused, Casey Pratt

Undergraduate Theses, Capstones, and Recitals

Although technology could be used to combat inequality, it is instead increasing it. This paper discusses how the unhoused population suffers at the hand of technological inequality despite being relatively offline. It presents theories on how this would change if we reapproached how technology is used to assist the unhoused. It suggests implementing blockchain as a resource as well as modifying the websites built to assist in accessing benefits. Employees at shelters are interviewed for this paper about their experiences with using digital resources to rehouse and restabilize the vulnerable. They are asked how the sites can be improved for …