Digital Commons Network^™

Accelerated Coupled Mode Model For Fiber Laser Amplifiers As An Averaged Dynamical System, Rebecca Bryant, Jacob Grosek, Jay Gopalakrishnan

Mathematics and Statistics Faculty Publications and Presentations

We apply a known theorem for simplifying dynamical systems with bounded error to a specific optical fiber waveguide problem, thereby supplementing the physical intuition and heuristics used in the optics community with proper mathematical justification. Using techniques from the averaging theory of dynamical systems, a reliable accelerated model based on the coupled mode theory (CMT) approach for a common fiber laser amplifier application is derived. Computational testing reveals that this accelerated model achieves a ∼4000x increase in computational speed compared to the CMT model while preserving high accuracy in key figures of merit such as output power and amplification efficiency. …

Modeling The Combined Effects Of Forest Fire And Climate Change On Snow-Water Storage In The Oregon Cascades, Joseph D. Vigil

Dissertations and Theses

Forest fire and climate change are reshaping the snow hydrology of the Pacific Northwest of the United States, yet the combined effects of these disturbances on snow accumulation, storage, and melt timing remain poorly quantified in these Mediterranean mountain watersheds. This study integrates field-based snow and radiation observations with physically based modelling to evaluate how postfire forest structure, postfire snow albedo decay, and future climate change influence snow-water storage in the Breitenbush watershed of the western Oregon Cascades. This work was conducted as part of a broader U.S. Army Corps of Engineers effort to improve postfire hydrologic prediction and flood …

Rethinking College Curricula: Preparing Students With The Skills Needed For Successful Cultural Resource Management (Crm) Careers, Kate Monti Barcalow, Shelby L. R. Anderson

Anthropology Faculty Publications and Presentations

Postsecondary education is at the forefront of preparing the next generation of cultural resource management (CRM) practitioners for the workforce. We conducted a study from 2022 to 2023 to gain perspective on improving postsecondary CRM curricula in order to better prepare students for careers in CRM. Our research included semi-structured interviews of nine key consultants with careers in CRM, along with a survey of the broader CRM professional community in the Pacific Northwest, USA. Results from the research identified the necessary skills for new college graduates, areas where CRM programs could improve their curricula, and various approaches in and out …

Multiple-Valued Quantum Automata For Robotics, Yuchen Huang

Dissertations and Theses

This dissertation introduces a new type of quantum automata, their encoding and circuit realization. I concentrate on possible applications in robotics. Several methods and application of quantum automata and quantum circuit-based controllers for elementary robotic systems, with a focus on humanoid robot motion, emotion, and behavior generation are illustrated in detail. The research introduces several novel methodologies that bridge quantum computing principles with robotic control, aiming to overcome the limitations of classical deterministic and probabilistic approaches.

The dissertation first presents a quantum-circuit-based framework for generating non-repetitive and expressive (e)motions in a humanoid robot actor, using superposition and entanglement to produce …

Evaluating The Impact Of Leading Pedestrian Intervals And Curb Extensions On Conflict Frequency And Severity, Sophia Semensky

Dissertations and Theses

Leading Pedestrian Intervals (LPIs) and curb extensions are commonly implemented countermeasures intended to improve pedestrian safety at signalized intersections. While LPIs have a well-established crash reduction record, fewer studies have evaluated their impacts using surrogate safety measures or examined how curb extensions interact with LPIs to influence pedestrian-vehicle conflicts. This thesis investigates the effects of LPIs and curb extensions on pedestrian safety using detailed conflict data collected at eleven signalized intersections in the Portland, Oregon metropolitan area.

Approximately 600 hours of video data were collected across four matched intersection pairs and three before–after sites. Pedestrian and vehicular volumes, turning speeds, …

Scale-Dependent Particle Transport Over Urban-Like Roughness In Turbulent Flow, Rae Riddle

Dissertations and Theses

This study employs direct numerical simulation (DNS) to investigate the dispersion of inertial particles in turbulent flow over three-dimensional urban-like roughness at Reτ = 200. Particles with Stokes numbers St = 5, 25, and 100 are tracked over cubic arrays with spanwise spacings Sy from 2h to 32h, where h = δ/8 and δ is the half-channel height, alongside a smooth-wall reference case. The results reveal scale-dependent particle responses characterized by three distinct regimes. First, high-inertia particles (St = 100) align strongly with mean secondary flows, exhibiting organized plumes above roughness elements. Their vertical transport peaks at intermediate spacing …

Pivot: Plan For Institutional Vitality And Organizational Transformation, 2025-2026 Report, Office Of Academic Affairs, Research And Graduate Studies, Richard Tankersley, Shelly Chabon

Office of Academic Affairs Publications

This report documents the conduct and results of PIVOT's first review cycle, from its September 2025 launch through the submission of recommendations to President Ann Cudd on February 23, 2026. Track 1 reviewed 293 academic programs, each by three to five academic leaders, with calibration by the Deans' Council and feedback from units before classifications were finalized. Resulting classifications were 25 Grow, 85 Sustain, 112 Revitalize, and 71 Sunset. Track 2 reviewed 163 units through a Core Review Team, producing 7 Invest, 61 Sustain, 54 Reassess, 28 Restructure/Consolidate, and 13 Phase Out classifications. The report presents financial modeling projecting approximately …

A Comprehensive Calibration Framework For The Northwest River Forecast Center, Geoffrey Walters, Cameron Bracken, Brad Gillies, Leah Pope, Henry Pai, Sonali Chokshi, Victor Stegemiller, Stephen King, Julie Bracken, Taylor Dixon, Multiple Additional Authors

Mathematics and Statistics Faculty Publications and Presentations

We present a comprehensive framework developed by the Northwest River Forecast Center for calibrating hydrologically diverse basins. The framework includes models for snow, soil moisture, routing, channel loss, and consumptive use. Data inputs include a wide range of open-access datasets for meteorology, land use, topography, and land cover. The framework uses conceptual hydrologic models to handle basins with various hydrologic regimes including rain-driven and snowmelt-dominated basins. We also develop a flexible automatic calibration system that can handle numerous unobservable model parameters in a computationally efficient manner. A single-basin automatic calibration run can typically be completed on a modern laptop in …

From Reclamation To Restoration: Remaking Nature On Portland's Peninsula, Theus Richards

University Honors Theses

This environmental history of the North Portland Peninsula is a critical case study of a landscape in transition, where new "natures" have been constructed through shifting projects of reclamation and restoration. The Port of Portland, who controlled the Peninsula, transformed the marshy bottomlands near the confluence of the Columbia and Willamette Rivers to accommodate greater networks of industrial infrastructure and expand their capacity for global trade. Beginning in 1967, the Port began dredging operations to fill Ramsey Lake to make way for the construction of Rivergate Industrial District. Through this process, Smith & Bybee Lakes were set aside as a …

Asymmetric Airfoil Selection For A Small-Scale Vertical Axis Wind Turbine: A Numerical Study, Babak Ranjbaran, Yonatan Afework Tesfahunegn, Raul Bayoan Cal, Ármann Gylfason

Mechanical and Materials Engineering Faculty Publications and Presentations

Vertical-axis wind turbine (VAWT) efficiency depends mainly on the aerodynamic properties of the airfoils used in their blades. During each rotation of the turbine, the blade experiences a range of angles of attack (AOAs) with respect to the relative wind, resulting in a variation of its contribution to the overall performance of the turbine. This paper leverages the capabilities of XFoil for preliminary performance analysis and ANSYS Fluent for detailed Computational Fluid Dynamics (CFD) simulations. The initial selection of airfoils is based on geometric characteristics and their potential for high tangential force coefficients. The asymmetric airfoils were selected by maximizing …

Intrusion Detection Latency: The Neglected Metric, Sandhyarani Dash, John M. Acken

Electrical and Computer Engineering Faculty Publications and Presentations

Accuracy remains the dominant evaluation metric in Intrusion Detection System (IDS) research, yet an IDS that detects attacks too late is functionally equivalent to one that fails—particularly in Internet of Things (IoT) environments. In operational settings, the timing of detection shapes both the scope of adversarial activity and the feasibility of effective response. To the best of our knowledge, latency (the speed at which intrusions are identified) has received no systematic attention. Our analysis of published IDS papers reveals that latency is defined inconsistently—often referring to inference, communication, computation time, or combinations of these-leading to incomparable performance claims. To close …

Sweep Angle Effects Of Flow Over A Seal Whisker-Inspired Undulated Cylinder, Trevor Dunt, Christin T. Murphy, Ondrej Fercak, Raúl Bayoán Cal, Jennifer A. Franck

Mechanical and Materials Engineering Faculty Publications and Presentations

Flow over a seal whisker-inspired undulated cylinder at swept back angles is computationally investigated, comparing the vortex shedding, forces, and wake characteristics to those of an equivalent smooth geometry. Numerous prior studies have demonstrated that undulated cylinders can reduce mean drag and unsteady lift oscillations; however, none have isolated the effects of the sweep angle resulting from whisker positioning in flow. Inspired by the active control seals exert over their whiskers while navigating and sensing in unsteady aquatic environments, this study investigates how such orientation influences the hydrodynamic performance of the geometry. Simulations are performed of flow across a rigid, …

Pdxscholar Annual Report 2025, Julia Stone, Bertrand Robinson, Stacey Schlatter, Carolee Harrison

Library Faculty and Staff Publications and Presentations

This PDXScholar Annual Report covers the period between January 1, 2025, and December 31, 2025. This report demonstrates PDXScholar’s continued impact through readership data, new and growing collections, and comments and feedback from our users.

Arid: Agglomerative Regionalization Via Information Divergence, A Novel Clustering Algorithm For Geo-Spatial Data, Joshua David Sills

Dissertations and Theses

Regionalization is a clustering problem that seeks to partition geospatial data into geographically contiguous regions while remaining internally homogeneous in their attributes. It has been successfully applied towards the development of urban planning, natural resource discovery, and ecological analysis. Existing popular approaches optimize homogeneity using Euclidean or variance-based criteria, which ignore distributional differences such as variance shifts, multimodality, and higher-order dependence. This thesis introduces ARID (Agglomerative Regionalization via Information Divergence), a spatially constrained agglomerative clustering framework that replaces distance-based merging with an information-theoretic, Ward-like criterion that utilizes the Kullback-Leibler (KL) divergence. ARID constructs a neighborhood graph from coordinate space and …

Using Soil-Plant-Atmosphere Continuum Modeling To Evaluate Drought Tolerance In The Urban Environment, Md Jahidul Islam, Samantha Hartzell

Urban Ecosystem Research Consortium of Portland/Vancouver

Global climate change expansion in the past few years is affecting the urban environment in the Pacific Northwest. The Mediterranean climate, combined with climate change, is making conditions more severe for plant function and ecosystem services through increasing soil moisture limitation. As a result, identifying the changes in plant physiological processes caused by soil moisture limitation is important for conservation and restoration initiatives.

This research uses the Photo3 model to quantify gas exchange, plant water use, and water use efficiency under urban environmental conditions in Portland, Oregon. Meteorological data required for the model simulation were obtained from the weather station …

Ecoroof Runoff Mitigation Comparison By Photosynthetic Pathway In Three Species Of Interest, Harper Thomson, Samantha Hartzell

Urban Ecosystem Research Consortium of Portland/Vancouver

Stormwater management is critical as urban areas expand and impervious surfaces cover more area. Ecoroofs are increasingly deployed to attenuate roof runoff (mean reduction 33–42% in Portland studies) and peak flows (up to 88% in Portland studies). However, few studies have compared plant functional types, or more specifically photosynthetic pathways in ecoroof hydrologic performance, especially as it relates to seasonal rainfall variability. While sedum (a Crassulacean Acid Metabolism or CAM species) is popular for its drought resilience, its nocturnal stomatal opening behavior may limit evapotranspiration driven water loss compared to C3 or C4 photosynthetic species. In this study, nine modular …

Proceedings Of The 24th Annual Urban Ecology & Conservation Symposium March 16, 2026, Urban Ecosystem Research Consortium Of Portland/Vancouver

Urban Ecosystem Research Consortium of Portland/Vancouver

These proceedings document the agenda and abstracts for presentations and posters from the 24th annual conference organized by the Urban Ecosystem Research Consortium of Portland/Vancouver (UERC) which occurred on March 16, 2026. The UERC is a consortium of people from various universities and colleges, state and federal agencies, local governments, non-profit organizations and independent professionals interested in supporting urban ecosystem research and creating an information-sharing network of people that collect and use ecological data in the Portland/Vancouver area. The annual conference has an open call for abstracts. The UERC organizing committee selects the final oral and poster presentations, along with …

Nonstationary Flood Frequency Analysis For Urban Watersheds Using Open-Source Bayesian Software: Contrasting Case Studies From Texas, C. Haden Smith, Brian Skahill, David A. Margo

Mathematics and Statistics Faculty Publications and Presentations

Urban flood frequency analysis faces unique challenges as land development alters watershed hydrology, producing nonstationary flood records. This study demonstrates nonstationary flood frequency analysis (NSFFA) using RMC-BestFit, an open-source Bayesian software, through two Texas case studies. Brays Bayou at Houston (96 years of record) exemplifies an urbanized watershed with increasing flood trends; a step-logistic model captures both the abrupt increase in mean flood magnitude around 1968 and the progressive decrease in log-space variance as urbanization homogenized runoff response. O.C. Fisher Reservoir (169 years of record) exhibits decreasing trends attributed to brush encroachment and groundwater extraction; despite a sinusoidal model achieving …

Effects Of Fib-Based Sample Preparation On Semiconductor Strain Characterization, Daniel Carl Hedinger

Dissertations and Theses

Channel strain engineering has been an important topic in semiconductor manufacturing due to the significant carrier mobility gains it can provide. The need for strain characterization at the individual device level, combined with the rapidly shrinking size of semiconductor devices, has led to development of various transmission electron microscopy (TEM) based strain characterization methods including nano beam electron diffraction (NBD). These methods rely on focused ion beam (FIB) sample preparation to produce election transparent TEM samples. This dissertation studies the effect of different FIB sample preparation modalities on the measured strain in p-type 14nm FinFET devices. TEM samples were produced …

A 2030 Energy Transition Pathway For Bishkek, Kyrgyz Republic, Kasiet Nurlanbekova

University Honors Theses

Bishkek remains heavily dependent on thermal generation to meet winter electricity and heating demand, while seasonal air pollution and growing urban energy demand continue to place pressure on aging infrastructure. Although Kyrgyzstan has adopted renewable energy targets, implementation remains limited, and winter reliability in the capital continues to depend on centralized combined heat and power generation.

This study evaluates whether Bishkek can improve its seasonal electricity adequacy by 2030 through alternative supply portfolios built around currently planned projects and moderate renewable additions. Using a seasonal portfolio model, the baseline and scenario 1 are compared. The baseline includes CHP-1 modernization, CHP-2, …

Building Connections With Graduate Students Through Credit-Bearing Instruction, Michelle Desilets, Kimberly Pendell

Library Faculty and Staff Publications and Presentations

Graduate students often need support with research skills and other professional development that is under-recognized by their programs. Librarians play a key role in helping students fill in these gaps. This case study reviews student feedback on a librarian-developed and -delivered credit-bearing course. The course, Library Research and Scholarly Communication Fundamentals, is offered to graduate students across all disciplines. The curriculum is flexible and applicable to each student’s research, covering topics such as researching literature, citation and data management, and publishing in scholarly journals. The course has generated positive and constructive feedback from students, encompassing themes of self-efficacy, improved research …

Mud Sound Speed Profile Constraints From Sub-Bottom Arrival Times, Charles W. Holland

Electrical and Computer Engineering Faculty Publications and Presentations

Arrival times of sub-bottom reflected paths together with co-located direct measurements of the angle of intromission provide narrow constraints on the sediment sound speed profile. Measurements of these two quantities at the central New England Mud Patch in March 2017 indicate that the average sound speed gradient in the upper 3m and upper 9m of mud is 6 s1. Gradients of 5 s1 and 7 s1 over the upper 9m are too small and large, respectively. Below 9m, the sandmud transition interval has a gradient of 200 s1. VC

Quantitative Comparison Of Different Ultrasound Simulation Approaches For Civil Engineering Applications, Fabian Dethof, Simon Schmid, Jean-Marie Henault, Thomas Schumacher, Sylvia Kessler, Salvador Villalobos

Civil and Environmental Engineering Faculty Publications and Presentations

Interpreting ultrasonic waveforms is often challenging, especially in the presence of tilted boundaries that introduce multiple reflections, mode conversions, and echoes. To analyze such complex signal patterns, wavefield simulations provide a valuable tool. To ensure confidence in the simulation results, the accuracy of the numerical method is crucial. Another consideration when using simulations is their computational expense. Especially in civil engineering applications, large structures need to be investigated, which may not be feasible given the available resources. In this study, different numerical methods and software implementations commonly used for simulations in civil engineering are compared, including the Elastodynamic Finite Integration …

Madwoman Makings: The Modern Girl As An Object Of Fear And Fascination In Unno Jūza’S "Mrs. Hirumi's Refrigeration Bag", Eliza Joy Mortimer

University Honors Theses

This thesis argues that Unno Jūza's 1937 short story "Mrs. Hirumi's Refrigeration Bag" uses the sensational tropes of deviant detective fiction to both stage and interrogate interwar Japanese anxieties around gender, science, and modernity. Focusing on the figure of Mrs. Hirumi—a scientifically empowered and sexually assertive female plastic surgeon who dismembers and cryogenically preserves her husband—the author reads her as a radical iteration of the Japanese Modern Girl character. By drawing on scholarship on deviant detective fiction, imperial modernity, and Kazue Harada's concept of (re)productivity, this thesis demonstrates how the short story both reproduces misogynistic criminological discourse and unsettles heteronormative …

How Does Communication Breakdown Impact Group Cohesion Over The Lifespan Of A Team?, Hannah Dyche

University Honors Theses

Communication is one of the main determinants of whether a team or group achieves a successful outcome; when it starts to erode, the team's overall goal often erodes with it. Communication breakdown within teams directly impacts group cohesion, causing small misunderstandings to escalate into larger conflicts. Every team experiences ups and downs, but maintaining a strong foundation of communication and continually strengthening it will prevent this breakdown.

Most of the existing research on team dynamics focuses on corporate environments. By shifting the focus to a short-term academic team, this thesis shows how communication breakdown impacts group cohesion over the lifespan …

How Agile Became The Design Philosophy Of Ai Fishbowl Under Real-World Constraints, Jad Saad

University Honors Theses

This capstone review examines the development of AI Fishbowl, a public-facing, interactive artificial intelligence system, as a case study in how Agile methods evolve from a project management tool into a design philosophy under real-world constraints. Although the project adopted an Agile workflow early on through a Kanban-style task management approach, the initial system design and architecture were still shaped by a largely plan-first mindset. This created a mismatch between flexible process and rigid design assumptions, which became increasingly apparent as the team moved from high-level architecture into implementation.

A critical turning point occurred when early architectural plans proved difficult …

A Cryptographic Perspective On The Verifiability Of Quantum Advantage, Nai-Hui Chia, Honghao Fu, Fang Song, Penghui Yao

Computer Science Faculty Publications and Presentations

In recent years, achieving verifiable quantum advantage on a NISQ device has emerged as an important open problem in quantum information. The sampling-based quantum advantages are not known to have efficient verification methods. This article investigates the verification of quantum advantage from a cryptographic perspective. We establish a strong connection between the verifiability of quantum advantage and cryptographic and complexity primitives, including efficiently samplable, statistically far but computationally indistinguishable pairs of (mixed) quantum states (EFI), pseudorandom states (PRS), and variants of minimum circuit size problems (MCSP). Specifically, we prove that a) a sampling-based quantum advantage is either verifiable or can …

Bl(U)E Crab: Bluetooth Low Energy Connection Risk Assessment Benchmarking, Dylan Christopher Conklin

Dissertations and Theses

The usage of Bluetooth Low Energy (BLE)-based tracker devices for stalking has become a salient privacy concern. Detecting unwanted or suspicious trackers is challenging due to their cross-platform compatibility issues, inconsistent detection methods, and lack of an industry-wide standard for detecting malicious devices. BL(u)E CRAB, Bluetooth Low Energy Connection Risk Assessment Benchmarking, scans data and generates risk factors about nearby devices to classify them as suspicious or not. These risk factors include the number of encounters the user had with a device, the duration of time a device has been near the user, the distance a device has traveled …

Effect Of Degree Of Saturation On The Liquefaction Resistance Of Non-Plastic And Low-Plastic Soils, Kayla Rae Sorenson

Dissertations and Theses

Liquefaction and cyclic softening of fine-grained soils pose a significant hazard during earthquakes, yet the cyclic behavior of transitional soils such as silts remains poorly understood. Existing empirical liquefaction evaluation frameworks and ground improvement techniques are largely developed for sands and are not directly applicable to silts, particularly beneath existing infrastructure where conventional mitigation methods are often impractical or cost prohibitive. This knowledge gap is critical in regions such as the Pacific Northwest, where young, loosely deposited silts are prevalent and susceptible to seismic loading.

Microbially induced desaturation (MID) has emerged in recent years as a promising, minimally invasive ground …

Adolescent Math Anxiety: Teachers' Grouping Approach At The Intersection Of Multiple Student Identities, Dara Shifrer, Hannah Sean Ellefritz, David Hernandez-Saca, Allison Roda, Karla Santana Martinez

Sociology Faculty Publications and Presentations

Math anxiety represents a substantial barrier to many students’ math learning. In this paper, we apply interdisciplinary perspectives to data on over 13,200 ninth graders and their math teachers from the High School Longitudinal Study. Results suggest that being perceived as dis/abled relates to heightened math anxiety regardless of adolescents’ gender, or race and ethnicity. Our intersectional approach reveals that adolescents’ expressions of math anxiety do not always correspond with gender, racial, and ethnic stereotypes, with Black girls, Black boys, and Latine boys expressing relatively low levels of math anxiety. Finally, consistent with the principles of inclusion and universal design, …