Digital Commons Network^™

Implementing Super-Resolution Of Non-Stationary Tides With Wavelets: An Introduction To Cwt_Multi, Matthew Lobo, David A. Jay, Silvia Innocenti, Stefan A. Talke, Steven Dykstra, Pascal Matte

Civil and Environmental Engineering Faculty Publications and Presentations

Tides are often non-stationary due to non-astronomical influences. Investigating variable tidal properties implies a tradeoff between separating adjacent frequencies (using long analysis windows) and resolving their time variations (short windows). Previous continuous wavelet transform (CWT) tidal methods resolved tidal species. Here, we present CWT_Multi, a Matlab code that: a) uses CWT linearity (via the “Response Coefficient Method”) to implement super-resolution (Munk and Hasselman 1964); b) provides a Munk-Hasselman constituent-selection criterion; and c) introduces an objective, time-variable form of inference (“dynamic inference”) based on time-varying data properties. CWT_Multi resolves tidal species on time-scales of days and multiple constituents per species with …

Multicopter Drone Mass Distribution Impacts On Viability, Performance, And Sustainability, Miguel Figliozzi

Civil and Environmental Engineering Faculty Publications and Presentations

This short communication highlights the value of drone mass and its distribution, a topic that despite its importance has received scant attention in the rapidly growing drone literature. In particular, the focus is on the impact of mass distribution on drone viability, performance, and sustainability.

Exploratory Analysis Of Factors Affecting Home Delivery Returns, Michael Bronson, Miguel Figliozzi, Ali Riahi Samani, Sabya Mishra

Civil and Environmental Engineering Faculty Publications and Presentations

E-commerce and house deliveries have experienced a rapid growth in the last two decades. The return of online shopping products is an undesirable side effect of online shopping that has not been properly studied in the transportation literature. Utilizing binary logit models, this research answers two novel research questions focusing on the online shopping channel: (i) What household characteristics are associated with a higher or lower propensity to return online purchases? and (ii) What type of products contribute to positive return delivery rates? To answer these questions models are developed using data collected from a household online survey of e-commerce …

#Onygo, Géraldine Blattner, Amanda Dalola, Stéphanie Roulon

PDXOpen: Open Educational Resources

#OnYGo is an innovative first-year French language e-textbook, designed as Open Educational Resource (OER), for learning beginning French (equivalent to one year at an American university). It is inspired by a remix of task-based, multiliteracies and communicative approaches, which provides students with opportunities to engage with French language and culture in a variety of contexts and situations, across a range of modalities. Through a wide range of activities, students develop and practice their language skills, and reflect on their cross-cultural knowledge and positionality in their understanding of the vast francophone landscape. #OnYGo is a first-year textbook that takes a DEI-forward …

Helmholtz Cage Software Development For Cubesat Testing, Gustavo Cotom Lopez

Maseeh Summer Undergraduate Research Experience

The Helmholtz Cage is a 2-coil, 3-axis cage with the ability to precisely control the magnetic field at its center. The purpose of the cage is to be used as a testing device for our next CubeSat mission, OreSat0.5. Complete control over the cage was achieved with the python shell. Magnetometer data could be read when current flow was present.

Modeling Foliar Water Uptake In Quercus Rubra (Northern Red Oak), Camellia Tran

Maseeh Summer Undergraduate Research Experience

Foliar Water Uptake (FWU) is a common method through which trees and other plants absorb water through their leaves. This occurs when water is accessible and there's a difference in water potential between the leaf and its surroundings. Unlike the traditional process of water moving from roots to leaves and then evaporating, FWU involves water moving from the external environment into leaves. Several factors, including potential difference and leaf structure, influence FWU. This study shows how the process works and how it fits into the bigger picture of how plants manage water. This insight is important for predicting how plants …

Submerged Jet In Zero-G, Richard Sands

Maseeh Summer Undergraduate Research Experience

The rise dynamics of submerged jets refer to the behavior and characteristics of fluid jets that emerge from a source submerged beneath a liquid surface. These jets are commonly encountered in various natural and industrial settings, such as underwater volcanic eruptions, wastewater discharge, and fuel injection in marine engines. Understanding the rise dynamics of submerged jets is essential for numerous applications, including environmental impact assessments, propulsion system optimization, and volcanic hazard mitigation. All liquids and gases in the presence of gravity exert an upward force known as the buoyant force on any object immersed in them. Utilizing the Dryden Drop …

Python For Embedded Linux On Cubesats, Andrey Steblyakov

Maseeh Summer Undergraduate Research Experience

Small satellite missions, such as CubeSats, rely heavily on robust, flexible software architectures to manage diverse onboard subsystems and support complex mission objectives. This work presents key software development contributions to OreSat 0.5, a 2U nanosatellite developed by the Portland State Aerospace Society (PSAS). OreSat 0.5 incorporates double-digit onboard computers, solar cells, magnetorquers, Wi-Fi capabilities, and a Cirrus Flux Camera (CFC) to study cirrus clouds and test the Attitude Determination and Control System (ADCS). To streamline operations and testing, a REST API was designed for the Engineering Data Link (EDL). Replacing the previous command-line interface, this REST API enables remote …

Surface Chloride Content Testing On Oregon Concrete Bridges, Robert Garfias

Maseeh Summer Undergraduate Research Experience

Surface chloride content is measured along Oregon concrete bridges for bridge deterioration modeling. Measure predicted vs expected surface chloride content to determine Mean Square Error. Each bridge was located using ArcGIS Pro and GoogleMaps for distance measurements. Predicted surface chloride was calculated using empirical equations. A low MSE value corresponds to the forecasted value being closer to the actual predicted surface chloride content.

Interpretations Of A Protocol, Dana Paresa

Maseeh Summer Undergraduate Research Experience

Water heaters (WH) use a lot of energy. Stability of the electric grid is important and needs to be constantly managed. WHs can be used to help stabilize the electric grid during peak hours using load shifting. Can smart water heaters be used to curtail energy consumption? Utilities want reliable WH ET values to allow for effective grid management. Each manufacturer determines their own unique response to demand response commands. Some responses may be more desirable to utility, while others may be more desirable for customer comfort. Manufacturers are responsible for balancing responses to accommodate both customer and utility. Customers …

Turbulent Flow Over Coastal Areas, Weston Baker

Maseeh Summer Undergraduate Research Experience

With approximately half of the U.S. population residing in coastal areas, understanding the unique characteristics of air flow in these regions becomes critically important. The dynamic flow of air in urban environments affects the dispersal of pollutants, overall air quality, microclimates, human comfort levels, and the urban heat island (UHI) effect. Using computational fluid dynamics, this research aims to offer transformative solutions for enhancing air quality, optimizing building designs, and improving quality of life in coastal urban areas. Larger spacing between buildings results in larger zones of high-velocity flow. This flow can penetrate deeper into the urban fabric, facilitating better …

Classroom Analysis Using Audio, Nadine Ferguson

Maseeh Summer Undergraduate Research Experience

Currently, the assessment of instructors in classrooms are time consuming and biased. Active learning has been determined to be the best teaching strategy in STEM based classes, but determining if active learning strategies are being used can be difficult. Previously, a tool called Decibel Analysis for Research in Teaching (DART) has been used to determine active learning in classrooms based on audio. Audio can be used to determine active learning in a more efficient way than DART presents. The “who speaks when” analysis used Pyannote.audio an open source pretrained speaker diarization pipeline. The pipeline segments the audio and labels speakers …

Receiving Bluetooth Le Packets With Scμm, Jacob Louie

Maseeh Summer Undergraduate Research Experience

The SCμM chip uses the IEEE 802.15.4 communication standard to transmit and receive radio frequency signals. SCμM can already transmit a Bluetooth LE signal. Receiving a Bluetooth signal on this type of chip has never been done before. The work presents the experimental testing setup using ADC bits and GPIO connections on the SCµM development board, evaluates signal parameters such as frequency deviation and modulation, and analyzes packet decoding performance across power levels ranging down to -90 dBm.

Programming A Texas Instruments Microcontroller Unit (Mcu) For A Single Stage Buck/Boost Power Converter, John Yang

Maseeh Summer Undergraduate Research Experience

A power converter allows DC to be converted to AC voltage. The power converter used for this project has two MOSFETs per phase and contains inherent filters. The gate driver control signals are sinusoidally pulse-width modulated (PWM) to generate AC output waveforms. The primary goal was to replace the Arduino with a Texas Instruments 280049 MCU. An in-house designed controller board, named Mobo, seats a TI microcontroller board and provides PWM outputs via USB. The TI 280049 MCU is capable of replacing the Arduino for power electronic applications. Due to asynchronized PWM signals, A new Mobo will need to designed …

Understanding Nutrient Response In The Resource-Limited Crop Opuntia Ficus-Indica, Faye Parish

Maseeh Summer Undergraduate Research Experience

The Crassulacean Acid Metabolism (CAM) cycle is a unique photosynthetic process where CO2 is fixed during the day and the stomata open at night, minimizing water loss. Plants that undergo CAM photosynthesis thrive in arid and semi-arid regions, which are limited by low quantities of nutrients in the soil and water availability, due to low rainfall and high evapotranspiration rates. Prickly Pear Cactus, is a CAM crop used as feedstock in established arid and semi-arid regions and is a staple in many central and south American diets. With agricultural lands becoming increasingly arid globally, replacing low water use efficiency (WUE) …

Modeling Carbon Allotropes Using Machine Learning, Angel Chung

Maseeh Summer Undergraduate Research Experience

This study is training a machine learning model to identify each different carbon allotrope with the best thermal conductivity. This machine learning model uses the M3GNet model to predict the energies and forces of the carbon allotrope. Thermal conductivity is important to prevent chips from overheating. Carbon is known for its high thermal conductivity, however, there are many allotropes. M3Gnet is a massive pretrained neural network trained to predict interatomic potential energy given energies, forces, and stresses. Convergence of the model is achieved by varying the learning rate to the varying number of epoch.

Real-Time Length Sensing Of Artificial Bpa Muscles For Use In Characterizing Strain Gauge Measurements, Rochelle Jubert

Maseeh Summer Undergraduate Research Experience

Braided Pneumatic Actuators (BPAs) function as artificial muscles in biomimetic robotics, where real-time length feedback is essential for precise neural network control. While flexible strain gauge sensors offer potential for tracking muscle contraction, they are highly sensitive and produce noisy length readings. To address this challenge, we designed and fabricated a test rig featuring a linear potentiometer, linear bearings, and an extruded aluminum frame to minimize extraneous degrees of freedom and signal noise. Experimental actuation demonstrated that the rig provides high-precision displacement data, establishing a reliable benchmark for calibrating and characterizing future strain gauge sensor measurements across various muscle lengths …

Investigation Of Graphene Coatings On Iron-Based Alloys Through Mechanochemical Ball-Milling, Sebastian Lara

Maseeh Summer Undergraduate Research Experience

Ball milling was selected to investigate in this study due to its potential of cost-effectiveness, scalability, and reproducibility for graphene coatings. Stainless steel balls of 316L alloy and exfoliated graphene were employed in a custom-built ball milling machine within a hollow, 3D-printed, spherical PLA container. Experimentation involving variations in rpms, total milling time, and SS:EG ratio showed the importance of these factors in the final graphene coating quality with a 20:1 SS:EG mass ratio and an hour milling time providing the most promising results. Lower RPM Ball Milling allows for a lower energy graphene-layer shearing environment. Higher RPM intervals are …

Stability Of Structure-Aware Taylor Methods For Tents, Jay Gopalakrishnan, Zheng Sun

Mathematics and Statistics Faculty Publications and Presentations

Structure-aware Taylor (SAT) methods are a class of timestepping schemes designed for propagating linear hyperbolic solutions within a tent-shaped spacetime region. Tents are useful to design explicit time marching schemes on unstructured advancing fronts with built-in locally variable timestepping for arbitrary spatial and temporal discretization orders. The main result of this paper is that an s-stage SAT timestepping within a tent is weakly stable under the time step constraint

∆t ≤ Ch^1+1/s , where ∆t is the time step size and h is the spatial mesh size. Improved stability properties are also presented for high-order SAT time discretizations coupled …

Rasterizing Co2 Emissions And Characterizing Their Trends Via An Enhanced Population-Light Index At Multiple Scales In China During 2013–2019, Bin Guo, Tingting Xie, Wencai Zhang, Haojie Wu, Dingming Zhang, Xiaowei Zhu, Xuying Ma, Min Wu, Pingping Luo

Mechanical and Materials Engineering Faculty Publications and Presentations

Climate change caused by CO2 emissions (CE) has received widespread global concerns. Obtaining precision CE data is necessary for achieving carbon peak and carbon neutrality. Significant deficiencies of existing CE datasets such as coarse spatial resolution and low precision can hardly meet the actual requirements. An enhanced population-light index (RPNTL) was developed in this study, which integrates the Nighttime Light Digital Number (DN) Value from the National Polar-orbiting Partnership (NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) and population density to improve CE estimation accuracy. The CE from the Carbon Emission Accounts & Datasets (CEADS) was divided into three sectors, …

Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew

Dissertations and Theses

A Modular Multilevel Converter (MMC) is an attractive candidate in high power conversion due to its modularity and scalability. The energy storage element, namely the module capacitance in the MMC submodule circuit, is typically large and when scaled to convert high power, requires very bulky module capacitors. In addition to deteriorating the power density, the design necessitates the use of electrolytic capacitors, which further affects the overall converter efficiency and reliability. This research presents an MMC submodule topology and the accompanying modulation approach that reduces the submodule capacitance requirements significantly compared to conventional MMC topology (few micro-farads versus several milli-farads). …

Chemical Elements, Flavor Chemicals, And Nicotine In Unused And Used Electronic Cigarettes Aged 5–10 Years And Effects Of Ph, Monique Williams, Wentai Luo, Kevin J. Mcwhirter, Omeka Ikegbu, Prue Talbot

Chemistry Faculty Publications and Presentations

The concentrations of elements/metals, nicotine, flavor chemicals and acids were compared in the e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5–10 years. Metal analysis was performed using inductively coupled plasma optical emission spectroscopy; nicotine and flavor chemical analyses were performed using gas chromatography/mass spectroscopy. Of the 22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin, zinc) were often found in the e-liquids. Five elements had the highest average concentrations: copper (1161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L). Nicotine concentrations were always lower …

As You Like It: Building, Executing, And Assessing An Adaptable Library Instruction Program For First-Year Experience Courses, Joy I. Hansen

Communications in Information Literacy

Providing targeted experiences for first-year students both inside and outside the classroom is essential for building connections and creating a foundation for skill development necessary for academic success. Many first-year programs include a standalone course for incoming students or specific content weaved into existing course offerings. Information literacy skill-building holds an important place in these efforts; therefore, instruction librarians are provided additional opportunities to collaborate with faculty and reach students. Depending upon the size of the institution, however, the sheer number of first-year courses combined with shrinking library staff pose challenges. This Innovative Practices article is one library’s experience with …

Listening To First Generation College Students In Engineering: Implications For Libraries & Information Literacy, Emily Dommermuth, Linds W. Roberts

Communications in Information Literacy

First-generation college students (FGCS) in engineering bring a wealth of knowledge to their academic and social experiences in higher education, in contrast to deficit-based narratives that students are underprepared. By listening to FGCS’ own experiences navigating higher education and using information literacy in their project-based work, librarians and educators can better understand students’ funds of knowledge, social capital, and identities, as well as the institutional barriers that must be removed. This paper shares interview findings with (n = 11) FGCS and suggests implications for professional practice that are relevant to information literacy for design, project-based, or practitioner focused disciplines.

Metacognitive Awareness For Il Learning And Growth: The Development And Validation Of The Information Literacy Reflection Tool (Ilrt), Sara Robertson, Michele Burke, Kimberly Olson-Charles, Reed Mueller

Communications in Information Literacy

This article describes the development and validation of the Information Literacy Reflection Tool (ILRT), a metacognitive self-assessment for use with undergraduate researchers. It was developed as a teaching and learning tool with the intent to help students recognize and engage the metacognitive domain as a step toward developing personal agency and self-regulation as lifelong, metaliterate learners. Throughout the scale development, three studies were conducted with nine expert reviewers and 44 community college students to consider content and face validity and 542 community college students as part of an item-reduction and construct validation effort. The resulting scale is most appropriately construed …

Instruction Librarians’ Perceptions Of The Faculty–Librarian Relationship, Lisa Becksford

Communications in Information Literacy

This study investigates instruction librarians’ perceptions of their relationships with teaching faculty. Respondents to a survey of U.S. instruction librarians indicated that they tended to agree that their teaching was valued and they had autonomy in what they taught. However, the often one-time nature of library instruction limited their effectiveness as teachers, and respondents felt that faculty did not view librarians’ teaching as equivalent to their own. Respondents also reported a disconnect between their professional identities and others’ viewpoints, describing having their teaching role minimized or misunderstood by others, especially faculty. Additionally, a relationship was found between some aspects of …

Working Paper No. 67, Insights Into Project Cybersyn, Leah Herrera

Working Papers in Economics

This inquiry seeks to establish that back in the 1970s Chile’s “Project Cybersyn” offered novel approaches and specific technologies that appeared to have benefitted capitalism as a system. The Spanish name, SYNCO served as an acronym for Sistema de Información y Control. President Salvador Allende expected that the attributes associated with Project Cybersyn could assist his efforts in implementing his variant of socialism. Cybersyn consisted of a network (Cybernet), software (Cyberstride), computers, a economic simulator known as CHECO, and a control room (Opsroom.) Cybersyn reached an advanced prototype stage; however, its fate was also tied to the interests of the …

Working Paper No. 73, “Placing-Out”: Dealing With Vagrant Children In 19th Century America, Josephine Cannistra

Working Papers in Economics

This inquiry seeks to convince the reader that motivations of 19th century aid societies were not necessarily rooted in the welfare of vagrant children, but rather in the goals of bolstering American agriculture and creating a new generation of farmers out of children that likely would have otherwise proved a direct social and economic burden. While apprenticeships have a long history in the United States, the joining of apprenticeships and indentured labor formed a 19th century system of placing children out into rural homes as contracted workers. This system, as social movement from above, offered economic benefits to farmers and …

Working Paper No. 72, The 1849 Gold Rush And The Roots Of California’S Economic Development, Matthew Phan

Working Papers in Economics

The Californian Gold Rush, commonly referred to as the “1849 Gold Rush” proved to be a major event which brought significant change to California. This inquiry seeks to establish that this 1849 Gold Rush provided a foundation for a broadly shared prosperity through contributing to the advancement of California’s industry. The first part in this inquiry goes into some detail regarding how the gold rush got initiated, would become a major event for the world. The second part explores what changes the gold rush had brought for California’s industry, economic development, and broadly shared prosperity. The third part explains more …

Webinar: Individual Wayfinding In The Context Of Visual Impairment, Blindness, And Deafblindness, Amy Parker, Martin Swobodzinski

TREC Webinar Series

In this presentation we will highlight our past research on human indoor-outdoor wayfinding on an urban college campus. Our work is aimed at facilitating independent travel for people with blindness and low vision. Our research was funded by two successive grants from the National Institute for Transportation and Communities/US Department of Transportation. One of the central research questions sought to capture wayfinding preferences, information needs, and lived experiences of blind and low-vision pedestrian travelers. The projects afforded close collaboration with external partners, and foremost the American Printing House for the Blind. Our focus in the presentation will be on the …