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Articles 31 - 60 of 4174

Full-Text Articles in Physical Sciences and Mathematics

Pitching Fwar Vs Bwar As Predictors Of Team Success In The Mlb Regular Season, Jason Lee Jun 2026

Pitching Fwar Vs Bwar As Predictors Of Team Success In The Mlb Regular Season, Jason Lee

University Honors Theses

Pitching Wins Above Replacement (WAR) is an area of sabermetrics capable of being used to predict regular season success in Major League Baseball. Fangraphs WAR (fWAR) and Baseball Reference WAR (bWAR) were used to construct regression models to predict regular season winning percentage, to build logistic models to establish a relationship between pitching WAR and the probability to win an individual regular season game, and to overlay density plots to consider WAR accumulation by pitching role and observe the difference of impact between starter and relief pitchers. This research finds that while pitching fWAR and pitching bWAR are both statistically …


Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed Jun 2026

Rapid-Prototyping Nanofabrication: Lcd-Based Projection Lithography And Physical Vapor Deposition, Sabeel Saleem Mohammmed

University Honors Theses

The semiconductor industry's continued growth, driven in large part by demand for artificial intelligence hardware, has highlighted the need for greater workforce development in regions adjacent to major fabrication centers like Oregon's Silicon Forest. This capstone project lays the groundwork for a small scale and student led semiconductor fabrication lab at Portland State University by demonstrating two of the core steps in chip manufacturing: photolithography and thin film deposition. Rather than relying on conventional fixed reticles, this work explores a unique, low cost approach to patterning that uses an ultraviolet-compatible liquid crystal display (LCD) as a programmable reticle, allowing arbitrary …


A Novel, Embedding-Based Approach To Longitudinal Survey Data Imputation, Julia Rezvani Jun 2026

A Novel, Embedding-Based Approach To Longitudinal Survey Data Imputation, Julia Rezvani

University Honors Theses

Longitudinal surveys are ubiquitous in the social sciences as a means of tracking changes in behavior and opinions with time and identifying potential causal mechanisms. These surveys are frequently plagued by missing data and semantic drift, both of which limit their effectiveness and scientific utility. Imputation algorithms allow researchers to fill gaps in collected survey datasets, imperfectly reconstructing lost data. Although deep learning algorithms have been used in imputation to great success, approaches which simultaneously leverage the semantic and temporal structure of longitudinal surveys have not yet been developed. We propose a novel imputation architecture which is capable of leveraging …


Projected Climate Change Impacts On Soil Greenhouse Gas Emissions From A Restored Freshwater Marsh, Annika Hendrickson Jun 2026

Projected Climate Change Impacts On Soil Greenhouse Gas Emissions From A Restored Freshwater Marsh, Annika Hendrickson

University Honors Theses

Wetlands provide valuable ecosystem services, one of which is a wetlands ability to sequester carbon. Climate change and human land use threaten a wetlands ability to do so. Globally, 21% of wetlands have been lost since the 1700s. As a result, restoration of wetlands has been increasing. However, wetlands in the process of restoration emit more methane than degraded ones, and as the climate continues to change, these fluxes could respond. Projected sea level rise is expected to cause salt water to infiltrate coastal freshwater systems, increasing the salinity. Past research has found that increased salinity has led to suppressed …


Uniform Stability Of Katyusha In Strongly-Convex Settings, Don Li Jun 2026

Uniform Stability Of Katyusha In Strongly-Convex Settings, Don Li

University Honors Theses

Acceleration of convergence and reduction of variance constitute a trade-off in the design of stochastic optimization machine learning algorithms. Katyusha was introduced to address this trade-off, synthesizing Nesterov Accelerated Gradient (NAG) and Stochastic Variance-Reduced Gradient (SVRG) into a single first-order optimizer with promising empirical performance. However, the generalization properties of Katyusha remain largely unexplored. We conjecture that, in the smooth quadratic regime (i.e., under assumptions of strong convexity and smoothness of the loss function, and boundedness of gradients), Katyusha is uniformly stable in the sense of Bousquet and Elisseeff. Instantiating our framework for NAG, we extend the use of Lyapunov …


Oregon State Rank Assessment For Willamette Navarretia (Navarretia Willamettensis), Nora Dunkirk Jun 2026

Oregon State Rank Assessment For Willamette Navarretia (Navarretia Willamettensis), Nora Dunkirk

Institute for Natural Resources Publications

Oregon state conservation status assessment for Willamette Navarretia (Navarretia willamettensis) using NatureServe methodology, 2026.


The Method Of Periodic Averaging Applied To Reduced Coupled Mode Theory Models For Fiber Laser Amplifiers, Rebecca Nicole Bryant Jun 2026

The Method Of Periodic Averaging Applied To Reduced Coupled Mode Theory Models For Fiber Laser Amplifiers, Rebecca Nicole Bryant

Dissertations and Theses

Fiber laser amplifier (FLA) models are often implemented without rigorous mathematical justification or thorough numerical validation. Without a proper theoretical basis for assumptions and approximations, or a technical analysis of model performance, there is significant uncertainty about the limitations of any given reduced model and its suitability for an application. This research aims to address the lack of comprehensive assessment of FLA models by directly comparing distinct models and recommending a mathematical alternative to replace heuristic model-reduction techniques. The work in this dissertation is divided into two projects: a comparative study that uses existing FLA models to assess the validity …


Assessment Of The Readiness Of Architectural Design Companies To Adopt Eco-Friendly Nanotechnologies In Sustainable Building Design, Ashwaq Essa Al Khalil Jun 2026

Assessment Of The Readiness Of Architectural Design Companies To Adopt Eco-Friendly Nanotechnologies In Sustainable Building Design, Ashwaq Essa Al Khalil

Dissertations and Theses

Nanotechnology is emerging as a promising innovation in sustainable architectural design, although its adoption remains slow. Research highlights the advantages of incorporating nanotechnologies in architecture, including improved material performance, enhanced thermal efficiency, reduced energy consumption, improved durability, and progress toward the Sustainable Development Goals (SDGs). These advantages make nanomaterials a promising solution for sustainable building design, particularly in hot-climate regions where energy consumption and carbon emissions associated with conventional building design practices remain major concerns.

Despite this potential, nanotechnology adoption in architecture faces several challenges, including limited real-world applications, slow diffusion in practice, and persistent organizational, economic, and regulatory barriers. …


Introduction To Mathematical Analysis Ii, Beatriz Lafferriere, Gerardo Lafferriere, Mau Nam Nguyen Jun 2026

Introduction To Mathematical Analysis Ii, Beatriz Lafferriere, Gerardo Lafferriere, Mau Nam Nguyen

PDXOpen: Open Educational Resources

These lecture notes complement the book Introduction to Mathematical Analysis I, Third Edition, with sections on integration, numerical series, series of functions, and selected advanced topics. Together, both volumes support a one semester or two-quarter course on introductory mathematical analysis.

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Applications Of Prior And Novel Computational Tools In Mental Health Treatment, And Their Potential To Uncover The Explanatory Gap, Ambika Vyas Jun 2026

Applications Of Prior And Novel Computational Tools In Mental Health Treatment, And Their Potential To Uncover The Explanatory Gap, Ambika Vyas

University Honors Theses

The explanatory gap is a widely discussed concept in scientific and philosophical literature. In neuroscience, the solution to the explanatory gap is highly sought out, but the general consensus is that it is unsolvable. Numerous articles discuss the explanatory gap alongside computational tools and how these tools could aid neuroscientists in uncovering the mental health explanatory gap. However, significant developments in machine learning have been made since 2020, coinciding with the rise in Large Language Models (LLMs). This thesis is a literature review on computational methods, tools, and devices developed and utilized by researchers to improve how mental health disorders …


Developing A High-Resolution Off-Axis Common-Mode Digital Holographic Microscope, Lucy Cook Jun 2026

Developing A High-Resolution Off-Axis Common-Mode Digital Holographic Microscope, Lucy Cook

University Honors Theses

Off-axis digital holographic microscopy (DHM) is a powerful tool for 3D, non-invasive live-cell tracking without moving parts. However, traditional setups face an inherent dilemma: split-path interferometers offer high spatial resolution but poor temporal stability, while more stable common-mode configurations are historically limited to lower numerical aperture (NA) regimes. This thesis bridges that gap by scaling a common-mode DHM architecture into a high-resolution benchtop instrument featuring NA = 0.65 objectives, paired with a high-power 520 nm laser source to combat transmission losses and sustain imaging frame rates across an expanded optical footprint. We map the multi-variable design space required to satisfy …


Conello Vendor Marketplace Capstone: A Review On The Capstone Process And Computer Science Degree, Levi Hauck Jun 2026

Conello Vendor Marketplace Capstone: A Review On The Capstone Process And Computer Science Degree, Levi Hauck

University Honors Theses

This Capstone Review Thesis discusses the current structure of the Computer Science Degree path and Computer Science Capstone at PSU. This thesis reviews the Conello Vendor Marketplace Capstone, a project designed to help address the issue of teambuilding in the workplace. It points out ways in which teamwork and organization is an underdeveloped skill in Computer Science. During the Capstone project, the project management method of Agile development was recommended and used. However, it became clear that the team, leader included, had a gap in knowledge and skills to be successful, as well as a lack of experience in team …


Not Everyone Gets A Tree: Housing Values, Street Trees, And Equity In Portland, Matthew Moller Jun 2026

Not Everyone Gets A Tree: Housing Values, Street Trees, And Equity In Portland, Matthew Moller

University Honors Theses

Street trees are positively associated with Portland home sale prices, but exposure and capitalization are uneven by race/ethnic neighborhood context. Urban trees are ecological assets, but their economic and equity implications remain uneven. This thesis examines street-tree exposure and 2023 residential sale prices in Portland, Oregon (n = 6,414) using a mixed-methodology hedonic design. Ordinary least squares models measure inventoried street-tree counts within 20m, 50m, and 100m buffers together with structural controls and census-block racial and ethnic context. Trees are positively and significantly associated with logged prices at all radii, with scale-sensitive magnitudes and modestly better fit as wider buffers. …


Hillslope Aspect And Other Potential Controlling Factors On The Spacing Of Periglacial Stone Stripes In Se Oregon, Blue Hansen Jun 2026

Hillslope Aspect And Other Potential Controlling Factors On The Spacing Of Periglacial Stone Stripes In Se Oregon, Blue Hansen

University Honors Theses

Stone stripes are a type of patterned landscape that can be polygenetic in origin, but in the High Lava Plains province are interpreted to be relict periglacial features based on similarities to active stone stripe formation in current periglacial settings. Periglacial stone stripes are hypothesized to form via frost process, including ice-driven cracking and soil heave which is dependent on temperature, long-term differences in temperature may contribute to differences in stone stripe patterns or density. Stone stripes in Oregon and Idaho have previously been studied using field techniques, but there is room for reexamination of temperature controls on hillslope density …


Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad Jun 2026

Shallow-Marine Crinoid Genera May Have Been More Resilient Across Permian Extinction Events In Terms Of Richness Than Deep-Marine Crinoid Genera, Amelia C. Kolstad

University Honors Theses

Throughout the Phanerozoic, one of the most successful phyla of marine invertebrates has been Echinodermata. Echinodermata was particularly successful throughout the Paleozoic, with class Crinoidea making up a majority of occurrences. The proportion of echinoderm occurrences that are crinoids declined massively at the end of the Permian and continued to decrease into modern day, never fully recovering. One of the factors thought to have been so important for crinoid success in the Paleozoic and their decreasing success throughout geologic time has been their propensity for success in shallow-marine environments, though crinoids also exist within deep-marine environments. This study seeks to …


Agile In The Age Of Ai: Considerations And Improvements For Streamlining Developer Workflows, Stephen Feng Jun 2026

Agile In The Age Of Ai: Considerations And Improvements For Streamlining Developer Workflows, Stephen Feng

University Honors Theses

This paper examines the integration of AI language models into Agile developer workflows during a six-month software development project. Using the development of SagacityWall, a mindfulness-based social media application built by a team of eight undergraduates, it identifies three key areas in Agile processes where AI provided meaningful leverage: translating business requirements into actionable developer work tickets, accelerating framework research and technology stack decisions, and reducing onboarding friction through AI-assisted code scaffolding and Behavior-Driven Development story formatting. The study finds that AI meaningfully boosted productivity across these stages – not by replacing developer judgment, but by reducing overhead at each …


Investigating An Energy-Preserving Spectral Finite Difference Numerical Method For A Wave Equation On The Metric Graph, Tue Minh Tran Jun 2026

Investigating An Energy-Preserving Spectral Finite Difference Numerical Method For A Wave Equation On The Metric Graph, Tue Minh Tran

University Honors Theses

To investigate the accuracy and long-term energy conservation of a spectral finite difference numerical method for a wave equation on metric graphs. In conservative systems, numerical methods should preserve total energy. However, explicit finite difference methods require impractically small space steps and exhibit energy drift at end points. To address these limitations, a spectral finite difference method is implemented using a Fourier transformation. This semi-spectral method improves stability at endpoints while maintaining second-order accuracy, achieving an overall error of O(∆t2). We implement the semi-spectral method on the IEEE14 metric graph and provide visuals showing the initial condition …


Modeling Turbulent Accretion Flows Around Black Holes: Azimuthal Flux Derivative Density Curves In 3d Mhd Simulations, Sasmitha Purushothaman, Matthew D. Duez, Pavan Chawhan Jun 2026

Modeling Turbulent Accretion Flows Around Black Holes: Azimuthal Flux Derivative Density Curves In 3d Mhd Simulations, Sasmitha Purushothaman, Matthew D. Duez, Pavan Chawhan

University Honors Theses

When modeling two-dimensional axisymmetric accretion disks around Kerr black holes, setting the azimuthal terms of the MHD equations to zero causes the loss of turbulence and dynamo effects. In this paper, we use three-dimensional models to identify the turbulence that arises from azimuthal flux derivatives (AFDs) and create probability density functions to characterize them. We establish a pipeline for calculating the AFDs, creating a distribution, and normalizing it. Then, we plot the dependence of the conditional probability of the AFDs on density, magnetic field strength, and velocity for the continuity and magnetic induction equations. Future research can take this information …


Comparing The Sensitivity And Degree Of Boolean Functions Via The Hypercube, Anne-Caroline Rupp Jun 2026

Comparing The Sensitivity And Degree Of Boolean Functions Via The Hypercube, Anne-Caroline Rupp

University Honors Theses

This thesis studies three complexity measures of total Boolean functions f:{0,1}n → {0,1}: maximum sensitivity s(f), polynomial degree deg(f), and spectral sensitivity λ(f), where λ(f) is defined as the spectral norm of the adjacency matrix of the sensitivity graph. Building on the results of Aaronson et al., we examine the inequality chain √s(f) ≤ λ(f) ≤ deg(f) and investigate whether all three quantities can be simultaneously equal.

The first part of the thesis reverse engineers the equality cases of the two known inequalities to isolate necessary extremal conditions on both the Fourier structure of f and the local geometry …


Oregon State Rank Assessment For Straggling Gilia (Allophyllum Gilioides), Lindsey K. Wise May 2026

Oregon State Rank Assessment For Straggling Gilia (Allophyllum Gilioides), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Straggling gilia (Allophyllum gilioides) using NatureServe methodology, 2026.


Arylation Of Nitrogen, Oxygen And Carbon Nucleophiles By Aryl(Tmp)Iodonium Salts, Joseph Jordan Hatton May 2026

Arylation Of Nitrogen, Oxygen And Carbon Nucleophiles By Aryl(Tmp)Iodonium Salts, Joseph Jordan Hatton

Dissertations and Theses

Substituted aromatic rings are present in industry in a plethora of organic molecules such as pharmaceuticals, agrochemicals, materials and beyond. Therefore, methods for broadly installing aryl rings into other compounds to create substituted aromatic rings are valuable to many organic chemists. Historically these transformations are achieved through methods such as nucleophilic aromatic substitution and metal catalyzed cross-coupling. Nucleophilic aromatic substitution is a user-friendly method in this space but is limited by reliance on specific electronics. Metal catalyzed cross-coupling reduced the dependence on electronics in this space, but metals are generally unattractive reagents due to high costs, toxicity and challenges with …


An Integrated Framework For Memory-Centric Analysis: From Trace Collection To Co-Design, Dhruv Gajaria, Prajwal Challa, Yasodha Suriyakumar, Joseph Manzano, Nathan Tallent, Andrés Márquez May 2026

An Integrated Framework For Memory-Centric Analysis: From Trace Collection To Co-Design, Dhruv Gajaria, Prajwal Challa, Yasodha Suriyakumar, Joseph Manzano, Nathan Tallent, Andrés Márquez

Computer Science Faculty Publications and Presentations

IntroductionThe memory wall phenomenon—where advances in processor performance significantly outpace those in memory subsystems-poses a fundamental challenge for contemporary computing systems. In memory-bound applications, memory subsystem behavior dominates performance, yet existing analysis approaches present significant limitations: detailed microarchitectural simulators require days to weeks to simulate modest workloads; hardware performance counters provide only aggregate statistics that obscure temporal and spatial access patterns; and scaled simulation approaches face challenges in capturing contention effects, bandwidth saturation, and interference patterns that emerge at larger scales. These limitations reflect a processor-centric design philosophy—in both performance analysis tools and system co-design methodologies—that is increasingly misaligned with …


Improving Explainability And Interpretability Of Neural Networks Via Hyperparameter-Extended Influence Functions, William Breslin May 2026

Improving Explainability And Interpretability Of Neural Networks Via Hyperparameter-Extended Influence Functions, William Breslin

Dissertations and Theses

Understanding how model predictions and training outcomes vary with changes in data, features, and modeling choices is central to explainable artificial intelligence. This dissertation introduces a unified framework for explainability by generalizing classical influence functions to encompass user-defined hyperparameters embedded in the training loss, model architecture, or data representation. By extending influence functions in this way, the framework broadens their applicability and integrates multiple explainability techniques into a single, coherent approach. It provides a common mathematical foundation linking data impact, feature importance, and model design analysis, and supports a broad class of additional explainability analyses beyond these settings. The demonstrated …


Design And Implementation Of Error Estimators For Finite Element Eigenvalue Problems, Gabriel Esteban Pinochet Soto May 2026

Design And Implementation Of Error Estimators For Finite Element Eigenvalue Problems, Gabriel Esteban Pinochet Soto

Dissertations and Theses

We present three publications, all encompassed under the umbrella of a posteriori error estimation theory for eigenvalue problems for finite element discretizations. The central objective of the research is the development of a general framework for the study of reliable estimation of eigenvalues and eigenspaces. We introduce applications to problems of theoretical interest as well as problems arising in real-life scenarios, such as optical fibers. The first paper focuses on the implementation of a dual-weighted residual error estimator for a nonselfadjoint eigenvalue problems arising from the study of leaky modes in optical fibers---Maxwell's equations, Perfectly Matched Layers, and a conforming …


Local And Indigenous Knowledge, Innovation, And Sustainable Development: Creating Sustainable Futures Amidst Crisis Conditions At The Community Level, Carlos Andrés Arias May 2026

Local And Indigenous Knowledge, Innovation, And Sustainable Development: Creating Sustainable Futures Amidst Crisis Conditions At The Community Level, Carlos Andrés Arias

Dissertations and Theses

In 1987, the Brundtland Commission's Our Common Future (1987) made clear the need to reject longstanding development processes and focus on sustainable development. The Commission stressed that actual sustainable development integrates three elements: social development, economic development, and environmental protection. Though developed nations have achieved economic growth through conventional and extractive development practices, these practices have intensified natural disasters driven by climate change, increased food insecurity, and deepened poverty. This has acutely impacted Indigenous and local communities, many of whom face crisis conditions, such as war, terrorism, civil disorder, and their aftermath. Even so, many of these communities successfully implement …


Oregon State Rank Assessment For Wiens' Dwarf Mistletoe (Arceuthobium Abietinum Ssp. Wiensii), Lindsey K. Wise May 2026

Oregon State Rank Assessment For Wiens' Dwarf Mistletoe (Arceuthobium Abietinum Ssp. Wiensii), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Wiens' dwarf mistletoe (Arceuthobium abietinum ssp. wiensii) using NatureServe methodology, 2026.


Oregon State Rank Assessment For Bedstraw Broomrape (Aphyllon Epigalium Ssp. Epigalium), Lindsey K. Wise May 2026

Oregon State Rank Assessment For Bedstraw Broomrape (Aphyllon Epigalium Ssp. Epigalium), Lindsey K. Wise

Institute for Natural Resources Publications

Oregon state conservation status assessment for Bedstraw broomrape (Aphyllon epigalium ssp. epigalium) using NatureServe methodology, 2026.


Crossing Boundaries: Brachinites And Their Diverse Asteroidal Origins, B. G. Rider-Stokes, F. A. Davies, T. H. Burbine, E. Maclennan, R. C. Greenwood, S. L. Jackson, M. Anand, Daniel Sheikh, M. M. Grady May 2026

Crossing Boundaries: Brachinites And Their Diverse Asteroidal Origins, B. G. Rider-Stokes, F. A. Davies, T. H. Burbine, E. Maclennan, R. C. Greenwood, S. L. Jackson, M. Anand, Daniel Sheikh, M. M. Grady

Geology Faculty Publications and Presentations

Brachinite meteorites are typically linked to the olivine-rich A-type asteroids. In this study, however, they appear to exhibit unexpected spectral diversity. Spectroscopic analysis of seven meteorites from the brachinite clan reveals two distinct populations in band parameters, overlapping with both the A-type and S-complex asteroids. This dual association shows that a single meteorite group can originate from multiple asteroid taxonomies. Notably, one S-complex-like specimen, Northwest Africa (NWA) 14,635, displays band parameters similar to those of asteroid (65803) Didymos, the target of the European Space Agency's (ESA) ongoing Hera mission. These results underscore the value of spectroscopic characterization of poorly understood …


Rosenzweig's Elements And Universal History, Martin Zwick Apr 2026

Rosenzweig's Elements And Universal History, Martin Zwick

Complex Systems Faculty Publications and Presentations

This paper uses Rosenzweig’s conception of the three elements of God, World, and Human from The Star of Redemption in a model of universal history. The model also has some relation to Rosenzweig’s geopolitical essay, Globus, which is very different from the meta-historical Star. Based on a systems-theoretic schema of events and processes, the model views human history in terms of three linked processes: a primary process labeled “World” – the origin and development of human society embedded in nature, a secondary process labeled “God” – the origin and development of the Axial religions and philosophies, and a …


An Infinite Set Of One-Range Addition Theorems Without An Infinite Second Series, For Slater Orbitals And Their Derivatives, Applicable To Multiple Coordinate Systems, Jack C. Straton Apr 2026

An Infinite Set Of One-Range Addition Theorems Without An Infinite Second Series, For Slater Orbitals And Their Derivatives, Applicable To Multiple Coordinate Systems, Jack C. Straton

Physics Faculty Publications and Presentations

Addition theorems have been indispensable tools for the reduction of quantum transition amplitudes. They are normally utilized at the start of the process to move the angular dependence within plane waves, Coulomb potentials, and the like, into a sum over spherical harmonics that allows the angular integration to be carried out. These have historically been “two-range” addition theorems, characterized by the two-fold notation r>=Max[r1,r2] and r< =Min[r1,r2] and comprising a single infinite series. More recently, “one-range” addition theorems have been created that have no such piecewise notation, but at the cost of the introduction of another infinite series. We use a very different approach to derive an infinite set of addition theorems for Slater orbitals, hydrogenic and Hylleraas wave functions, and so on, that retain the one-range variable dependence but have, at worst, a finite second series rather than an infinite one. In addition, unlike previous addition theorems, they are applicable to more than one coordinate system. One of these addition theorems may also be used for Yukawa-like functions that may appear late in the reduction of amplitude integrals, and we show its utility for an integral that has stubbornly defied reduction to analytic form for nearly sixty years. Finally, we craft indefinite integrals of 15 half-integer Macdonald functions multiplied by (inverse) powers and negative exponentials containing squares of the integration variable.