Digital Commons Network^™

A Systematic Review Of Research On Augmentative And Alternative Communication Brain-Computer Interface Systems For Individuals With Disabilities., Betts Peters, Brandon Eddy, Deirdre Galvin-Mclaughlin, Gail Betz, Barry Oken, Melanie Fried-Oken

Speech and Hearing Sciences Faculty Publications and Presentations

Augmentative and alternative communication brain-computer interface (AAC-BCI) systems are intended to offer communication access to people with severe speech and physical impairment (SSPI) without requiring volitional movement. As the field moves toward clinical implementation of AAC-BCI systems, research involving participants with SSPI is essential. Research has demonstrated variability in AAC-BCI system performance across users, and mixed results for comparisons of performance for users with and without disabilities. The aims of this systematic review were to (1) describe study, system, and participant characteristics reported in BCI research, (2) summarize the communication task performance of participants with disabilities using AAC-BCI systems, and …

Intermediate Effect Of The Covid-19 Pandemic On Prices Of Housing Near Light Rail Transit: A Case Study Of The Portland Metropolitan Area, Sangwan Lee, Liming Wang

Urban Studies and Planning Faculty Publications and Presentations

This study explored the dynamics of a residential property value premium for proximity to a light rail transit (LRT) station in the intermediate term (roughly two years) since the pandemic. We applied a longitudinal quasi-experimental design using repeat sales data from the Portland Metropolitan Area, Oregon. Our results indicate that the effect of the pandemic on prices of housing near LRT stations differs between single-family and multi-family markets. Since the pandemic outbreak, there has been no statically significant difference in the price appreciation between singlefamily (SF) housing within an LRT service area and otherwise similar SF homes; however, for multi-family …

Development Of A Configurable Real-Time Event Detection Framework For Power Systems Using Swarm Intelligence Optimization, Umar Farooq

Dissertations and Theses

Modern power systems characterized by complex topologies require accurate situational awareness to maintain an adequate level of reliability. Since they are large and spread over wide geographical areas, occurrence of failures is inevitable in power systems. Various generation and transmission disturbances give rise to a mismatch between generation and demand, which manifest as frequency events. These events can take the form of negligible frequency deviations or more severe emergencies that can precipitate cascading outages, depending on the severity of the disturbance and efficacy of remedial action schema. The impacts of such events have become more critical with recent decline in …

Modeling Environment For Testing A Distributed Energy Resource Management System (Derms) Using Gridapps-D Platform, Shiva Poudel, Sean Keene, Roshan Kini, Sarmad Hanif, Robert B. Bass, Jaime Kolln

Electrical and Computer Engineering Faculty Publications and Presentations

The electric power system is currently undergoing a major transition due to growing numbers of distributed energy resources (DERs) and increased distribution automation. If optimally managed and operated, DERs could provide flexibility and highly valuable grid services such as restoration, peak shaving, voltage regulation, and frequency support to maintain grid reliability. Different applications and enterprises, such as distributed energy resources management systems (DERMS), are being developed for coordinated and optimal operation of DERs. However, to attract sufficient DER participation and achieve the coordinated operation of DERs, systems and components must be interoperable and information exchange must be secure. Along this …

Arbuscular Mycorrhizal Fungi Colonization Response To Dike Removal In The Salmon River Estuary, Elinore Webb

Dissertations and Theses

Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with wetland plants and are important to the restoration of coastal estuaries. The purpose of this study was to assess the presence and colonization of arbuscular mycorrhizal fungi in Distichlis spicata from three formerly diked areas of the Salmon River Estuary to determine an initial understanding of the mycorrhizal community in tidal wetlands post-restoration. AMF were present in all four sample areas and total colonization ranged on average 39-72%. The reference site had the lowest levels of total colonization, which is contrary to the findings of studies of younger wetland restorations. Most importantly, …

Knowledge Overconfidence Is Associated With Anti-Consensus Views On Controversial Scientific Issues, Nicholas Light, Philip M. Fernbach, Nathaniel Rabb, Mugur V. Geana, Steven A. Sloman

Business Faculty Publications and Presentations

Public attitudes that are in opposition to scientific consensus can be disastrous and include rejection of vaccines and opposition to climate change mitigation policies. Five studies examine the interrelationships between opposition to expert consensus on controversial scientific issues, how much people actually know about these issues, and how much they think they know. Across seven critical issues that enjoy substantial scientific consensus, as well as attitudes toward COVID-19 vaccines and mitigation measures like mask wearing and social distancing, results indicate that those with the highest levels of opposition have the lowest levels of objective knowledge but the highest levels of …

Modeling And Analysing The Impact Of Heat Pump Water Heaters On Distribution Systems Using Gridlab-D, Midrar Adham

Dissertations and Theses

With the constant increase in energy demand, finding ways to reduce peak load and the energy-costs factors has become more imperative. Domestic water heating showcases a significant opportunity for such applications. Water heating is the second-highest energy consumer in the residential sector across the United States. Electric Water Heaters (EWHs), in particular, constitute nearly 43% of American household water heating energy consumption. Heat Pump Water Heater (HPWH), on the other hand, is an advanced water heating technology that has recently emerged in the United States residential market.

The objectives of this work are to develop a HPWH model and build …

A Privacy-Preserving Strategy For The Trust Layer Of The Energy Grid Of Things Distributed Energy Resource Management System, Mohammed Abdullah Alsaid

Dissertations and Theses

Emergent from the shadows of the traditional grid flaws, the Smart Grid (SG) idea was born and led by government mandates toward cleaner energy production. The SG represents the next generation of electricity distribution systems that subsume recent technological innovations. It uses digital communication between its components and entities to attain more automation, self-sufficiency, and reliability. Unfortunately, this relatively new concept is not flawless; the intrinsic reliance on increased digital communication spreads open attack paths for adversaries. Therefore, finding solutions that address information exchange vulnerabilities has become imperative.

The Energy Grid of Things (EGoT) is Portland State University's implementation of …

Drivers Of Spatiotemporal Eukaryote Plankton Distribution In A Trans-Basin Water Transfer Canal In China, Yuying Li, Faisal Hayat Khan, Jiamin Wu, Yun Zhang, Yeqing Jiang, Xiaonuo Chen, Yinlei Yao, Yangdong Pan, Xuemei Han

Environmental Science and Management Faculty Publications and Presentations

Planktonic eukaryotes are important components of aquatic ecosystems, and analyses of the whole eukaryotic planktonic community composition and function have far-reaching significance for water resource management. We aimed to understand the spatiotemporal variation and drivers of eukaryotic plankton distribution in the Middle Route Project of the South-to-North Water Diversion in Henan Province, China. Specifically, we examined planktonic assemblages and water quality at five stations along the canal and another one located before the dam in March, June, September, and December 2019. High-throughput sequencing revealed that the eukaryotic plankton community was primarily composed of 53 phyla, 200 genera, and 277 species, …

Gentle Action Theory As A Method Of Deliberative Democracy In Addressing The Lack Of Voice For Indigenous Students In Institutions Of Higher Education, Carma J. Corcoran

Amplify: A Journal of Writing-as-Activism

This paper examines how Indigenous college students attending non-tribal colleges and universities in the United States experience feelings of alienation and marginalization. The concept of democracy and deliberation from the model of the larger oppressive society is not a cultural norm. Civic engagement is experienced differently in Indigenous communities. This paper articulates the outcomes of a deliberative forum which examined the concept of democracy employing Gentle Action Theory as the method to provide the students an opportunity to share their thoughts and experiences and to express their frustrations and needs regarding their academic endeavors. The comparison of Traditional Ways and …

A Distributed Trust Model Simulator For Energy Grid Of Things Distributed Energy Resource Management System, Abdullah Barghouti

Dissertations and Theses

The evolution of networks into more distributed, self-reliant nodes has mitigated single-point failures that plagued traditional centralized networks. Applied to power grids, distributed systems can increase the integrity and availability of grid services while also offering a power management solution. However, while distributed networks provide scalability, security, and sustainability compared to centralized networks, their distributed nature makes them harder for anomaly detection and prevention. Incorporating a Distributed Trust Model (DTM) System into an Energy Grid of Things Distributed Energy Resource Management System (EGOT DERMS) allows grid participants to be characterized and their communication to be analyzed for possible attacks. A …

Modeling Postfire Effects On Snow Albedo And Forest Recovery Over A Chronosequence Of Burned Forests In The Triple Divide Region Of The Rocky Mountains, Anton J. Surunis

Dissertations and Theses

Wildfires impact snow albedo, forest cover, and forest structure and thus snow melt rate and snowpack supply for as long as 15 years following burn. These effects have not been quantified at fine spatial resolutions and long time periods at a watershed scale. I modeled the effects of postfire effects on snow albedo, snow-mass energy balance, and resulting snow-water equivalent (SWE) depth over a long-time scale and at a fine spatial resolution. Using a spatially and temporally distributed snow evolution model called SnowModel, I modeled postfire effects on snow albedo and forest structure over postfire recovery within 8 forest fires …

Proper Orthogonal Decomposition Of Reynolds And Dispersive Stresses In Turbulent Boundary Layers Over Multi-Scale Rough Patches, Catherine Virginia Spivey

Dissertations and Theses

Multi-scale rough patches are present in topologies such as urban canopies (cities) and natural landscapes (forests, ocean floors). The flow over such canopies is three-dimensional, with turbulent structures known as secondary flows present in the boundary layer due to the difference in rough surface heterogeneities. Three dimensional instantaneous velocities are analyzed within the roughness sublayer over three generations of multi-scale rough patches at nine vertical planes using particle image velocimetry obtained experimentally. The secondary structures present in the flow are identified in the form of Reynolds and dispersive fluctuations. Proper orthogonal decomposition is employed to characterize the imprint of the …

Development Of A Configurable Derms Test System In Gridapps-D, Sean James Keene

Dissertations and Theses

Distributed Energy Resources and their increased penetration within the power grid are a suitable method to provide essential reliability services. In order to do so, they must operate in aggregate. Aggregation of a wide variety of systems with varying standards and protocols is a complex task, which could benefit from rules and standards to support interoperability. To this end, the Portland State University Power Lab has developed the Energy Grid of Things project, which includes a Distributed Energy Resource Management System to provide aggregation and demonstrate the usage of an Energy Services Interface: a set of rules governing the interface …

Learning From Machines: Insights In Forest Transpiration Using Machine Learning Methods, Morgan Thornwell

Dissertations and Theses

Machine learning has been used as a tool to model transpiration for individual sites, but few models are capable of generalizing to new locations without calibration to site data. Using the global SAPFLUXNET database, 95 tree sap flow data sites were grouped using three clustering strategies: by biome, by tree functional type, and through use of a k-means unsupervised clustering algorithm. Two supervised machine learning algorithms, a random forest algorithm and a neural network algorithm, were used to build machine learning models that predicted transpiration for each cluster. The performance and feature importance in each model were analyzed and compared …

Toward Analyzing The Diversity Of Extractive Summaries, Aaron David Hudson

Dissertations and Theses

As the amount of text generated across the internet continues to increase, developing methods for processing that text to glean valuable insights is paramount. Automatic text summarization is one such method that aims to provide a concise and representative summary of input text, allowing users access to the most salient points from a large amount of textual data. However, in working with these summaries, especially those generated from social media data, questions arise about not only the quality of a summary, but also its ability to reflect the diversity of user perspectives. This work examines the quality of summaries with …

Stoneware And Earthenware From The Beeswax Wreck: Classification Of The Dubé Collection And Discussion Of The Interpretation Of The Materials In Protohistoric Sites, Vanessa Renee Litzenberg

Dissertations and Theses

Over the past three centuries, items from the Beeswax Wreck have been discovered on Oregon's northern coastline near Manzanita, including stoneware and earthenware fragments. While the stoneware and earthenware were not noticed by beachcombers washing ashore until more recently, similar artifacts have been noted within Indigenous sites for decades. While most of the analysis of the artifacts found in protohistoric settings are used to provide proof of a wreck or potentially a marker of the start of the contact period, this study aims to provide some context to the stoneware and earthenware sherds related to the wreck. The goal was …

Efficiency In The Upper Deschutes Basin: Understanding The Hydrosocial Implications Of Irrigation Canal Piping, Rebecca Anderson

Dissertations and Theses

In response to water scarcity, irrigation efficiency projects aim to conserve water for in-stream flow and agricultural use. Piping irrigation canals is a common irrigation efficiency method which reduces the loss of incidental recharge, resulting in trade-offs within a hydrosocial system. Few studies have focused on the consequences of canal piping and none have integrated a critical analysis of the social factors involved in deciding what constitutes 'efficient' water use. This study seeks to fill this gap by combining natural and social science to give attention to the scales and perspectives involved in irrigation efficiency canal piping and the material …

Ti–6al–4v Alloy Deposition Characteristics At Electrode-Negative Polarity In The Cold Metal Transfer–Gas Metal Arc Process, Tae Hyun Lee, Dong Hyuck Kam, Je Hoon Oh, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Although wire arc additive manufacturing (WAAM) of Ti alloys using gas metal arc yields a high deposition rate, cathode spots exhibit unstable behavior. In this study, the cold-metal-transfer process and an electrode-negative (EN) polarity were used in the WAAM process of the Ti–6Al–4V alloy. High-speed imaging was performed to investigate the mechanisms to stabilize cathode plasma jets, arc plasma, and molten metal transfer in the EN polarity. Arc plasma and cathode jets had the same direction, and sound cathode jets were shrouded by arc plasma in the EN mode. The metal transfer was also stabilized by balanced plasma formation under …

Technology Roadmap For Standards Of Healthcare Data Cyber Security: Influence Of Public Policy On Consumer Healthcare Cyber Security Protections, Alison Nalven, Courtney Wright, Jennifer Lynn Zeitouni, Nolan Thompson, Sara Ferdousi, Saumya Saxena

Engineering and Technology Management Student Projects

From the dot com boom to now the Internet of Things (IoT) and Machine Learning era, the evolving digital world that people live in has brought new challenges for protecting personal data and information. IoT devices, smart phones, numerous apps, and more, constantly collect personal health data with many positive intentions. However, the recent overturning of Roe vs. Wade by the United States Supreme Court has generated concerns in particular on who and how personal health data can be used by both governments and private companies with unintended consequences for users. Cyber security and regulations for protecting personal health data …

Ssita: Seal Serving Institutional Transformation Assessment: Excelencia In Education & Portland State University, Cynthia Carmina Gómez, Oscar Fernandez, Cristina Herrera, Emanuel Magaña, Allyson Meyers, Perla Pinedo, Rebecca Rodas, Tanya Sanchez

Global Diversity and Inclusion Publications and Presentations

In the Spring of 2022, Portland State University was invited to participate in Excelencia in Education’s pilot Seal Serving Institutional Transformation Assessment or SSITA. This SSITA report is a preliminary institutional assessment of Portland State University’s (PSU) efforts to intentionally serve Latiné students and advance degree completion. Between now and June 2023, a committee of faculty, staff, and students will lead the effort to complete a Seal of Excelencia application. We will reach out to all parts of the institution to gather additional information, data, and stories about how units serve our growing Latiné student population. The next round of …

Gis Training In Transportation And Environmental Justice For Promoting Student Success In Steam Education, Joowon Im, Alan Klein, Amruta Sakalker

TREC Final Reports

Transportation land uses have a significant impact on vulnerable ecologies, especially in a rapidly urbanizing region like Dallas-Fort Worth. To study this relationship, the research team will develop a pilot ArcGIS lab course to expose high school students to critical regional tools and technology. This course will demonstrate the connections between transportation planning and design and environmental justice. The College of Architecture Planning and Public Affairs at UT Arlington will partner with CityLab high school in the Dallas Independent School District to develop a four-week lab course curriculum in ArcGIS and other emerging regional mapping technologies.

High school students will …

An Introduction To Gis For Dallas, Texas High Schoolers, Joowon Im, Alan Klein, Amruta Sakalker

TREC Project Briefs

A summary of TREC research project NITC-RR-1468,GIS Training in Transportation And Environmental Justice for Promoting Student Success in STEAM Education.

Reimagine Fire Science For The Anthropocene, Jacquelyn K. Shuman, Jennifer K. Balch, Rebecca T. Barnes, Philip E. Higuera, Andres Holz, Multiple Additional Authors

Geography Faculty Publications and Presentations

Fire is an integral component of ecosystems globally and a tool that humans have harnessed for millennia. Altered fire regimes are a fundamental cause and consequence of global change, impacting people and the biophysical systems on which they depend. As part of the newly emerging Anthropocene, marked by human-caused climate change and radical changes to ecosystems, fire danger is increasing, and fires are having increasingly devastating impacts on human health, infrastructure, and ecosystem services. Increasing fire danger is a vexing problem that requires deep transdisciplinary, trans-sector, and inclusive partnerships to address. Here, we outline barriers and opportunities in the next …

An Essential Role For Tungsten In The Ecology And Evolution Of A Previously Uncultivated Lineage Of Anaerobic, Thermophilic Archaea, Steffen Buessecker, Marike Palmer, Dengxun Lai, Joshua Dimapilis, Xavier Mayali, Damon Mosier, Jian-Yu Jiao, Daniel R. Colman, Anna-Louise Reysenbach, Multiple Additional Authors

Biology Faculty Publications and Presentations

Trace metals have been an important ingredient for life throughout Earth’s history. Here, we describe the genome-guided cultivation of a member of the elusive archaeal lineage Caldarchaeales (syn. Aigarchaeota), Wolframiiraptor gerlachensis, and its growth dependence on tungsten. A metagenome-assembled genome (MAG) of W. gerlachensis encodes putative tungsten membrane transport systems, as well as pathways for anaerobic oxidation of sugars probably mediated by tungsten-dependent ferredoxin oxidoreductases that are expressed during growth. Catalyzed reporter deposition-fluorescence in-situ hybridization (CARD-FISH) and nanoscale secondary ion mass spectrometry (nanoSIMS) show that W. gerlachensis preferentially assimilates xylose. Phylogenetic analyses of 78 high-quality Wolframiiraptoraceae MAGs from …

Reducing Opioid Use Disorder And Overdose Deaths In The United States: A Dynamic Modeling Analysis, Erin J. Stringfellow, Tse Yang Lim, Keith Humphreys, Catherine Digennero, Celia Stafford, Elizabeth Beaulieu, Jack Homer, Wayne Wakeland, Multiple Additional Authors

Complex Systems Faculty Publications and Presentations

Opioid overdose deaths remain a major public health crisis. We used a system dynamics simulation model of the U.S. opioid-using population age 12 and older to explore the impacts of 11 strategies on the prevalence of opioid use disorder (OUD) and fatal opioid overdoses from 2022 to 2032. These strategies spanned opioid misuse and OUD prevention, buprenorphine capacity, recovery support, and overdose harm reduction. By 2032, three strategies saved the most lives: (i) reducing the risk of opioid overdose involving fentanyl use, which may be achieved through fentanyl-focused harm reduction services; (ii) increasing naloxone distribution to people who use opioids; …

Making Curry With Rice: An Optimizing Curry Compiler, Steven Libby

Dissertations and Theses

In this dissertation we present the RICE optimizing compiler for the functional logic language Curry. This is the first general optimizing compiler for a functional logic language. Our work is based on the idea of compiling through program transformations, which we have adapted from the functional language compiler community. We also present the GAS system for generating new program transformations, which uses the power of functional logic programming to provide a flexible framework for describing transformations. This allows us to describe and implement a wide range of optimizations including inlining, shortcut deforestation, unboxing, and case shortcutting, a new optimization we …

Silos In Higher Education Institutions: Shifting From Organizational Phenomena To A Practical Framework For Equitable Decision-Making, Mandi Sue Mizuta

Dissertations and Theses

As higher education has evolved, administrative and support functions have become more stratified and specialized, creating institutions with complex and compartmentalized organizational structures known as silos. These silos have a detrimental impact on institutions, employees, and ultimately the student stakeholders that they serve. Silos within higher education administration support services are readily acknowledged anecdotally; however, robust research to describe this phenomenon and actionable resources to address it are lacking. This multi-paper dissertation explores the theoretical implications and practical applications for using collaborative, intentional approaches to address what is argued to be at its core is a matter of equity. The …

Thermophysical Properties Of Inorganic Phase-Change Materials Based On Mncl2·4h2o, Kyung-Eun Min, Jae-Won Jang, Jun-Ki Kim, Chien Wern, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

Manganese (II) chloride tetrahydrate, classified as an inorganic phase-change material (PCM), can be used as a thermal energy storage material, saving and releasing thermal energy during its phase transitions. In this study, thermophysical properties, such as phase change temperatures, latent heat, and thermal conductivities, of four types of MnCl₂·4H₂O PCMs were investigated under single and dual phases (liquid-, solid-, and dual-phase PCMs) using differential scanning calorimetry (DSC) and a heat flow meter. PCMs with a liquid or dual phases exhibited superheating issues, and their melting temperatures were 7 to 10 °C higher than the reference melting …

Erasure Through Engagement: The Community Resettlement Of Isle De Jean Charles, Meghan Elizabeth Sullivan

Dissertations and Theses

The State of Louisiana and the national media have claimed that the community resettlement of Isle de Jean Charles (IDJC) is an example of a 'model resettlement' for communities experiencing the impacts of climate change. At the outset, the project was advocated and led by the tribal leadership of the Isle de Jean Charles Band of the Biloxi-Chitimacha-Choctaw Tribe. Although, through the course of the resettlement the supposed partnership between the State of Louisiana and the Tribe has dissolved. This study seeks to provide a robust and in-depth understanding of the planning and implementation process of the IDJC resettlement to …