Digital Commons Network^™

Optical Coherence Tomography Harmonization With Anatomy-Guided Latent Metric Schrödinger Bridges, Shuwen Wei, Blake E. Dewey, Samuel W. Remedios, Bruno Jedynak, Shimeng Wang, Peter Calabresi, Shiv Saidha, Aaron Carass, Multiple Additional Authors

Mathematics and Statistics Faculty Publications and Presentations

Medical image harmonization aims to reduce the differences in appearance caused by scanner hardware variations to allow for consistent and reliable comparisons across devices. Harmonization based on paired images from different devices has limited applicability in real-world clinical settings. On the other hand, unpaired harmonization typically does not guarantee anatomy consistency, which is problematic because anatomical information preservation is paramount. The Schrödinger bridge framework has achieved state-of-the-art style transfer performance with natural images by matching distributions of unpaired images, but this approach can also introduce anatomy changes when applied to medical images. We show that such changes occur because the …

Unsupervised Oct Image Interpolation Using Deformable Registration And Generative Models, Shuwen Wei, Samuel W. Remedios, Bruno Jedynak, Peter Calabresi, Shiv Saidha, Aaron Carass, Multiple Additional Authors

Mathematics and Statistics Faculty Publications and Presentations

Optical coherence tomography (OCT) images are often acquired as highly anisotropic volumes, where the scanning step is dense along the fast axis but sparse along the slow axis. This affects image analysis, such as image registration for longitudinal alignment. To create more isotropic volumes, bicubic interpolation can be used along the slow axis, but it generally produces blurry features. Registration-based interpolation can reduce blurriness, but often fails to generate realistic OCT images. Deep generative models can sample realistic images, but lack the structural consistency constraints required for interpolation. In this paper, we propose an unsupervised image interpolation method that combines …

The Tyrant King Of The Auction House: The Disastrous “Fine Artification” Of The Dinosaur, Amelia C. Kolstad

Anthós

This article examines how fine art auctioneers market dinosaur fossils as art pieces to wealthy collectors, depriving the paleontological field of specimens for scientific research. Drawing from recent examples of fossils sold at fine art auctions, this article notes how rising auction prices for specimens as ‘art’ prevent museums and research institutions from acquiring specimens for research and restoration. Kolstad concludes that the art auction houses’ marketing of fossils as art is detrimental to paleontological research. To protect fossils and their scientific value, Kolstad proposes alternatives, such as selling replicas to collectors and highlighting the importance of original specimens for …

Work In Progress: Using Internships As Means For Indirect Assessment Of Abet Criteria 3 “1-7” Student Outcomes, Robert Bass

Electrical and Computer Engineering Faculty Publications and Presentations

The Electrical & Computer Engineering (ECE) Department at Portland State University (PSU) has developed a Power Engineering Internship (PEI) program that provides engineering career development pathways within the electric utility industry. The PEI is supported by several U.S. Department of Energy grants that aim to develop quality career opportunities and develop a future electric utility workforce that represents the nation’s diverse populations. The PSU ECE Department intends to use surveys of internship participants as assessment tools for its ABET accreditation process, in particular, the ABET Criteria 3 Student Outcomes (SOs). SOs relate to the knowledge, skills, and behaviors that students …

Effects Of The Upwind Spanwise Heterogeneous Terrain On The Wind Resource Distribution, Haosen H.A. Xu, Tianxiang Yu, Raúl Bayoán Cal, Xiaowei Zhu

Mechanical and Materials Engineering Faculty Publications and Presentations

Wind energy has become increasingly crucial among renewable energy resources, and as the prerequisite for effective wind energy utilization, accurate wind resource assessments are hence prominent. Topography significantly affects near-surface wind fields and is thus an essential factor to be considered for wind resource assessment. However, few studies have addressed the wind resource distribution downwind of spanwise-heterogeneous terrains, which are frequently encountered in both natural and urban environments. To fill this gap, large eddy simulations were performed to investigate wind distributions over a uniform terrain downwind of terrains featuring spanwise-alternating strips of low and high surface roughness, and the high …

A Proposed Ehrenfeucht-Fraïssé Game Model For Natural Language Processing Generative Adversarial Networks, Don Li

Anthós

Large Language Models (LLM’s) (e.g., ChatGPT) constitute both a significant research area and commercial application of AI. Current major LLM’s are built on Generative Pre-Trained Transformer (GPT) neural network architecture to perform natural language processing (NLP) tasks. Generative Adversarial Network (GAN) is another popular neural network architecture, which leverages a zero-sum game between constituent neural networks within the architecture to train the GAN, and is widely used for visual data applications. This article proposes a new GAN architecture for NLP: an EF-GAN whose underlying algorithm uses Ehrenfeucht–Fraïssé (EF) games, a game-theoretic approach from model theory to determine elementary equivalence of …

Rock: Riesz Occupation Kernel Methods For Learning Dynamical Systems, Victor W. Reilly, Chau Nguyen, Kamel Lahouel, Anthony Kolshorn, Nicholas Fisher, Bruno Jedynak

Mathematics and Statistics Faculty Publications and Presentations

We present a representer theorem for a large class of variational problems, generalizing regression, finite element methods, and providing techniques for learning partial and ordinary differential equations (PDEs and ODEs). We apply our formulation to the multivariate occupation kernel method (MOCK) for learning dynamical systems from data. Our generalized method outperforms the MOCK method on most tested datasets, while often requiring considerably fewer parameters. Experiments are presented for learning ODEs and PDEs.

Mock: An Algorithm For Learning Nonparametric Differential Equations Via Multivariate Occupation Kernel Functions, Victoria A. Rielly, Kamel Lahouel, Ethan Lew, Nicholas Fisher, Vicky Geneva Haney, Michael Wells, Bruno M. Jedynak

Mathematics and Statistics Faculty Publications and Presentations

Learning a nonparametric system of ordinary differential equations from trajectories in a -dimensional state space requires learning functions of variables. Explicit formulations often scale quadratically in unless additional knowledge about system properties, such as sparsity and symmetries, is available. In this work, we propose a linear approach, the multivariate occupation kernel method (MOCK), using the implicit formulation provided by vector-valued reproducing kernel Hilbert spaces. The solution for the vector field relies on multivariate occupation kernel functions associated with the trajectories and scales linearly with the dimension of the state space. We validate through experiments on a variety of simulated and …

The Matryoshka Doll Prior – Principled Multiplicity Correction In Bayesian Model Comparison, Andrew Womack, Daniel Taylor-Rodríguez, Claudio Fuentes

Mathematics and Statistics Faculty Publications and Presentations

This paper introduces a general and principled construction of model space priors with a focus on regression problems. The proposed formulation regards each model as a “local” null hypothesis whose alternatives are the set of models that nest it. Assuming constant ratio of prior probabilities for any “local” null and its alternatives provides a natural isomorphism of model spaces (like a matryoshka doll), constituting an intuitive way to correct for multiplicity in Bayesian model selection and averaging problems. This isomorphism yields the Poisson distribution as the unique limiting distribution over model dimension under mild assumptions. We compare this model space …

Belonging: Data Reasoning, About Ourselves And Others, Eva Thanheiser, Molly Robinson, Simon Byeonguk Han, Amanda Sugimoto, Courtney Koestler, Mathew Felton-Koestler

Mathematics and Statistics Faculty Publications and Presentations

Using Watson’s belonging framework and GAISE II data reasoning, this lesson invites students to collect, analyze, and represent personal data. In doing so, they see themselves and their peers reflected in the work, reinforcing their value as active participants in both mathematical thinking and the classroom community.

Consumption Pressure In Estuaries Peaks At Intermediate Salinities, Catherine E. De Rivera, Amy A. Larson, Benjamin G. Rubinoff, Luna R. Soto, Seth L. Wright, Edwin D. Grosholz, Gregory M. Ruiz, Andrew L. Chang

Environmental Science and Management Faculty Publications and Presentations

The nature and strength of biotic interactions change along stress gradients, but the importance of these interactions across estuarine gradients is under studied. Here, we examined how consumption varies across estuarine salinity gradients by deploying standardized baits (‘squidpops’) to measure consumption pressure along the gradients of five estuaries in Oregon, USA. The relationship between consumption and stress was nonlinear: consumption pressure peaked slightly at mid salinity and decreased at low salinity, especially as temperature increased, in the five estuaries studied. This finding does not support either of two existing models for consumption across gradients, including the Consumer Stress Model and …

Fueling Adaptation: Collaborative Wildfire Governance In The Colorado Front Range Landscape, Mahmood Muttaqee, Cody Evers, Lindsay K. Campbell, Max Nielsen-Pincus, Olivia Awbrey, Kathryn Hixson, Michelle Johnson, Erika Svendsen

Environmental Science and Management Faculty Publications and Presentations

Collaborative governance plays a critical role in wildfire risk mitigation efforts. This study examines collaborative wildfire governance networks within the Colorado Front Range, a landscape that was designated under the USDA Forest Service's Wildfire Crisis Strategy (WCS). Collaborative governance networks in the Colorado Front Range leverage partnerships across multiple organizational actors including federal, state, and local agencies, non-profits, fire districts, and research institutions. Through survey data collected from 281 respondents revealing a collaborative network of 401 organizations, the study aimed to identify the structure, capacity, and gaps in governance networks addressing wildfire risk in the Colorado Front Range. Survey results …

Urban Heterogeneity Drives Dissolved Organic Matter Sources, Transport, And Transformation From Local To Macro Scales, Rebecca L. Hale, Kristina G. Hopkins, Krista A. Capps, John S. Kominoski, Jennifer L. Morse, Allison H. Roy, Shuo Chen, Annika Quick, Andrew J. Blinn, Liz Ortiz Muñoz, Gwendolynn Folk

Environmental Science and Management Faculty Publications and Presentations

Urbanization reshapes dissolved organic matter (DOM) sources, transport, and transformations through changes in vegetation, hydrology, and management of waste and water. Yet the impacts of urbanization on DOM are variable within and among cities. Predicting heterogeneous responses to urbanization is challenged by diverse human activities and underlying biophysical variation along stream networks. Using data from the 486 largest urban areas in the continental United States and seven focal cities, we identified macro and local scale urban gradients in social, built, and biophysical factors that are expected to shape DOM. We used these gradients and the literature to develop hypotheses about …

Permafrost And Structural Controls On Holocene Bedrock Landslide Occurrence Around Eyjafjörður, North‐Central Iceland, Adam Booth, Halldór G. Pétursson

Geology Faculty Publications and Presentations

Rapid, transient, landscape‐scale changes associated with deglaciation can condition slopes for failure and trigger bedrock landslides. However, the mechanisms leading to paleo rock slope failures following the last glacial period are challenging to infer because observations of how both landsliding and potential driving factors were distributed in space and time are limited. Here, we map and analyze the spatiotemporal pattern of 676 post‐glacial bedrock landslides around Eyjafjörður in north‐central Iceland using 2‐m resolution digital elevation data generated from optical stereo satellite imagery. Frequency‐ratio analysis demonstrates that after controlling for slope, landslides are most overrepresented within 2.6 km horizontal distances from …

The Petrology Of The Ozerki Meteorite Constrained By Electron Backscatter Diffraction And X-Ray Computed Tomography, Alice Macente, Luke Daly, Sammy Griffin, Maria Gritsevich, Jarmo Moilanen, Josh Franz Einsle, Patrick Trimby, Chris Mulcahy, Jonathan Moffat, Alexander M. Ruzicka

Geology Faculty Publications and Presentations

Combining electron backscatter diffraction (EBSD) with X-ray computed tomography (XCT) offers a comprehensive approach to investigate shock deformation and rock texture in meteorites, yet such integration remains uncommon. In this study, we demonstrate the synergistic potential of XCT and EBSD in revealing deformation metrics, thereby enhancing our understanding of petrofabric strength and shock-induced deformation. Our analysis focuses on the Ozerki (L6, S4/5, W0) meteorite fall, which was instrumentally observed on June 21, 2018, and subsequently recovered by the Ural's branch of the Russian Fireball Network (UrFU) recovery expedition a few days later. The trajectory analysis conducted by the Finnish Fireball …

The Geography Of Rock Glaciers In The American West, Allison Reese Trcka, Andrew G. Fountain, Bryce Allen Glenn

Geology Faculty Publications and Presentations

Rock glaciers are relatively common in conterminous United States west of the 100° meridian, yet their distribution and number are not well known. Using aerial and satellite imagery, we inventoried the population of rock glaciers, yielding 2,257 rock glaciers totaling 234.28 km² with an area of uncertainty of 7 percent. Of these, 1,561 (155.44 km²) are considered intact (moving) and 696 (76.84 km²) relict. Based on published estimates of ice content, total water-equivalent volume is roughly 2.52 km³. Rock glacier elevations increase from the northwest (Washington) to the southeast (Colorado), following a spatial …

Subito 2025, Portland State University. School Of Music & Theater

Subito: Student Voices from Portland State University School of Music & Theater

Issue 8, Spring 2025

Explore the boundless creativity and passionate inquiry within this year's journal. Topics range from microtonal tuning systems unrestricted by cultural boundaries, to creative tips from composer and interdisciplinary artists, to analysis of Arvo Pärt and poetic ruminations of singing Beethoven's 9th.

Descending An Inclined Plane With A Large Language Model, Justin C. Dunlap, Ryan Sissons, Ralf Widenhorn

Physics Faculty Publications and Presentations

[This paper is part of the Focused Collection in Artificial Intelligence Tools in Physics Teaching and Physics Education Research.] We present a study in which a version of a common conservation of mechanical energy introductory physics problem, an object released on an inclined plane, is given to OpenAI’s GPT-4 large language model (LLM). We investigate how different permutations of object, action verb, and property of the incline impact the responses of the LLM. The problem setup and prompting was left purposefully minimal, requiring the LLM to state multiple assumptions to justify the final answer. We specifically studied how different keywords …

Clea Labs For Stellar And Cosmological Astronomy Bottled For Silicon Macintosh, Hansika Reddy Bandela, Yuktha Shetty, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for Windows, but the authors have bottled them for Silicon Macintosh computers.

Clea Labs For Planetary, Stellar, And Cosmological Astronomy Configured For 64-Bit Windows 11+ Machines, Itan Altamirano, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for 32-bit Windows machines but PSU student Itan Altamirano reconfigured installation programs to bypass steps that ask for DVDs and allowing these 32-bit programs to work on 64-bit Windows 11+ computers.

Clea Labs For Planetary Astronomy Bottled For Silicon Macintosh, Yuktha Shetty, Hansika Reddy Bandela, Jack C. Straton

Physics Faculty Publications and Presentations

Project CLEA -- CONTEMPORARY LABORATORY EXPERIENCES IN ASTRONOMY -- develops laboratory exercises that illustrate modern astronomical techniques using digital data and color images.

These Labs were developed for Windows, but the authors have bottled them for Silicon Macintosh computers.

Citizen’S Rare Plant Watch, Nora Dunkirk, Gabriel Campbell, Kris Freitag

Rae Selling Berry Seed Bank and Plant Conservation Program

Rare species data for plants is lacking, hindering land management decisions and conservation outcomes. With Citizen's Rare Plant Watch, we empower citizen scientists to provide the “eyes on the ground” and collect data needed for conservation decision making in Oregon.

Largely Enhanced Out-Of-Plane Electromechanical Coupling Effects In Two-Dimensional Molybdenum-Disulfide/Boron-Nitride Heterostructures, Qiong Liu, Vijay Kumar Choyal, James E. Morris, Timon Rabczuk, Xiaoning Jiang, Xiaoying Zhuang

Electrical and Computer Engineering Faculty Publications and Presentations

The electromechanical coupling effects in two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted great interest. However, for 2D TMDs, piezoelectricity is confined to the basal plane, and the flexoelectricity-derived out-of-plane electromechanical response is usually faint, limiting the applications of this material family using the out-of-plane electromechanical effects. Here, this work reports a facile strategy to greatly enhance the out-of-plane electromechanical response of hexagonal molybdenum disulfide (2H-MoS₂) nanoflakes by stacking monolayer hexagonal boron nitride (h-BN) on 2H-MoS₂ nanoflakes to form MoS₂/BN heterostructures. The d^eff/₃₃ coefficient of MoS₂/BN can reach a value comparable …

Estimating Electric Power Consumption Of Grid-Enabled Residential Heat Pump Water Heaters, Dana Paresa, Robert Bass

Electrical and Computer Engineering Faculty Publications and Presentations

We present two methods for estimating compressor electric power consumption of residential heat pump water heaters. Power is calculated using data from voltage and current instrumentation, which add costs and potential failure points to the unit. The two methods presented herein use thermal instrumentation or derived data that are typically included within modern residential heat pump water heaters. One method uses data from lower and upper tank temperature sensors. The other method uses an attribute that is commonly available within grid-enabled flexible load heat pump water heaters. For both methods, fit equations were derived, for which coefficients are tuned to …

A 14-Year Content Analysis Of School-Family Partnership Publications In Counseling: Trends, Gaps, And Future Directions, Yi-Wen Su, Dan Li

Counselor Education Faculty Publications and Presentations

This content analysis examined 55 articles on school-family-community partnerships published in counseling journals between 2010 and 2024, identifying trends in publication type, methodology, and population focus. Most articles (54.54%) were conceptual, with Professional School Counseling leading in publication volume. Limited empirical research and a lack of focus on diverse populations were noted, with only 18.18% addressing racial minorities (primarily Latino and African American) and 5.45% focusing on rural communities. Four primary strategies for strengthening partnerships emerged: Inclusivity, Leadership and Empowerment, Equity-Focused, and Consistent Communication—each aligning with the school counselor’s roles in fostering collaborative, equitable partnerships. Recommendations emphasize a need for …

Evading A Post-Truth World: Rorty’S Foundationless Philosophy For An Acculturating Education, Madhu Narayanan

Educational Leadership and Policy Faculty Publications and Presentations

A challenge for educators is how to teach in a “post-truth” world. Lies, fake news, and a gleeful disregard for facts – what I collectively term mis/information – all seem to undermine the very project of education. The pragmatism of Richard Rorty holds promise to address such issues. I first argue that Rorty’s philosophy of education is of limited use, whereas his broader thoughts on a philosophy without foundations are more relevant. I then suggest that a way forward is to evade the fight against post-truth dynamics altogether. An insistence on rational objectivity and foundational truth are at the root …

Rising From The Ashes: Reading Impacts And The Effects Of Recovery Educational Services Following A Major Natural Disaster, Tiffanie Lousia Lambert

Educational Leadership Professional Doctorate Dissertations

This Improvement Science Dissertation examined solutions to improving literacy outcomes for students in an elementary school that experienced a wildfire during the pandemic. School data revealed lagging reading growth among students displaced by the wildfire despite educational recovery efforts. A root cause analysis to understand students' limited reading recovery led to more global concerns about school-wide literacy programming and the limited use of evidence- based approaches. School-wide data revealed that fewer than 30% of students in the school met literacy benchmarks since the wildfire. Though the fires disproportionally impacted low-income neighborhoods with higher representation of English Learners and students receiving …

Beyond Traditional Education: Graduation Rates At An Alternative High School, Kayla Dawn Marie Crook

Educational Leadership Professional Doctorate Dissertations

The study addressed the problem of practice of improving on-time graduation rates for students in alternative education settings. Traditional educational systems often fail to meet the unique needs of students in alternative education programs, which could lead to increased barriers towards on-time graduation. Based on improvement science principles, this research utilized Plan-Do-Study-Act (PDSA) cycles to systematically test and refine prioritized change ideas to mitigate these barriers with the goal of increasing graduation rates at the focus school. These change ideas included improving social emotional learning through teacher coaching, personalizing attendance calls, and developing individualized student success plans. Through rapid iterative …

Addressing Disparities Among Latine Students In Special Education, Jesabel Jannette Centeno

Educational Leadership Professional Doctorate Dissertations

This study used Improvement Science to understand and address the overrepresentation of Latine students identified with specific learning disabilities (SLD) in elementary school settings. It highlighted the processes and systems that impacted Latine students' educational opportunities and services--emphasizing the need for culturally and linguistically aligned instructional practices. The study was set in a suburban school district in the Pacific Northwest, where many Latine students received special education services. It investigated the root causes of SLD over-identification among these students. It suggested that enhancing educational outcomes required a focused effort to reduce over- and under-identification in special education. The document now …

Osa-Diff: An Origin Sampling Based Adversarial Attack Using Diffusion Models, Shayan Jalalipour, Banafsheh Rekabdar

Computer Science Faculty Publications and Presentations

Diffusion models are becoming an increasingly popular emerging technology, however their use in adversarial attacks remains a scarcely explored topic. We show that diffusion models can be used to create end-to-end hidden adversarial perturbations with high rate of success, and propose a novel diffusion based adversarial attack that allows for substantially faster training time (through improved convergence on high quality images) and with substantially less computational overhead than typical diffusion model training