Digital Commons Network^™

Transportation Planning In An Aging Society, Shengxiao (Alex) Li

PSU Transportation Seminars

By 2030, all Baby Boomers (those born between 1946 and 1964) will be 65 and older in the U.S. However, the understanding of how Baby Boomers travel differently from the previous generations, and the opportunities and challenges of older people's travel, do not keep pace with the increasing number of older people. This presentation starts with an overview of transportation policies for older people and challenges, followed by several empirical studies investigating older people's generational travel differences, vehicle ownership over the life course, and the interaction of technology usage and travel among older people. It concludes with a policy agenda …

The Green New Deal And Transit Investment, Eric Bruun

PSU Transportation Seminars

I have spent much of my professional life advocating for high quality transit infrastructure even if it takes a long time to build. I now believe we must focus on investments that can reduce greenhouse gas generation quickly. I cite some examples of how slowly projects have been built compared to peer nations and explain why.

Faculty Senate Monthly Packet October 2023, Portland State University Faculty Senate

Faculty Senate Monthly Packets

The October 2, 2023 monthly packet includes the October agenda, appendices, and the Faculty Senate minutes and attachments from the meeting held October 2, 2023.

A One-Dimensional Volcanic Plume Model For Predicting Ash Aggregation, D. W. Hoffman, L. G. Mastin, Alexa R. Van Eaton, Stephen Solovitz, Raul Bayoan Cal, J. K. Eaton

Mechanical and Materials Engineering Faculty Publications and Presentations

During explosive volcanic eruptions, volcanic ash is ejected into the atmosphere, impacting aircraft safety and downwind communities. These volcanic clouds tend to be dominated by fine ash (μm in diameter), permitting transport over hundreds to thousands of kilometers. However, field observations show that much of this fine ash aggregates into clusters or pellets with faster settling velocities than individual particles. Models of ash transport and deposition require an understanding of aggregation processes, which depend on factors like moisture content and local particle collision rates. In this study, we develop a Plume Model for Aggregate Prediction, a one-dimensional (1D) volcanic plume …

Transportation Academies As Catalysts For Civic Engagement In Transportation Decision-Making, Nathan W. Mcneil, Keith Bartholomew, Matthew Ryan

Urban Studies and Planning Faculty Publications and Presentations

Citizen planning academies, which became popular in the 1990s, are increasingly being used in transportation planning and decision-making contexts. By making use of a longer-term, multiweek educational format, transportation academies have the potential to reduce barriers and enhance community capital leading to more meaningful and sustained government community interaction. This paper tracks the rise of transportation academies in North America, and provides a detailed look at two academies: one in Portland, Oregon with a 30-year history, and another recently launched in the Salt Lake City, Utah region. Postacademy surveys of participants provided data that illuminated whether the transportation academy model …

The House Full Of Otters: Recalling Human–Sea Otter Relationships On An Indigenous Oregon Coast, Douglas Deur, Peter Hatch, Hannah Wellman

Anthropology Faculty Publications and Presentations

Sea otters have held a special role in the cultural, spiritual, and economic life of Native American communities throughout recorded time. Along the coast of what is now Oregon, Native oral traditions recall a rich history of human encounters with sea otters, and speak of the species’ ubiquity, significance, and sentience. Native people also hunted sea otters, fashioning their uniquely dense fur into chiefly robes and using the pelts in ways central to community life — presaging the species’ later role in the global fur trade. Archaeological evidence of sea otter use can be found in sites of diverse antiquity …

Place For Sociohydrology In Sustainable And Climate-Resilient Agriculture: Review And Ways Forward, Soham Adla, Mohammad Faiz Alam, Melissa Haeffner, Murugesu Sivapalan

Environmental Science and Management Faculty Publications and Presentations

Given the increasing demand for high-quality food and protein, global food security remains a challenge, particularly in the face of global change. However, since agriculture, food and water security are inextricably linked, they need to be examined via an interdisciplinary lens. Sociohydrology was introduced from a post-positivist perspective to explore and describe the bidirectional feedbacks and dynamics between human and water systems. This review situates sociohydrology in the agricultural domain, highlighting its contributions in explaining the unintended consequences of water management interventions, addressing climate change impacts due to/on agriculture and incorporating human behaviour into the description of agricultural water systems. …

Development Of Prediction Method For Dimensional Stability Of 3d-Printed Objects, Kyung-Eun Min, Jae-Won Jang, Jesik Shin, Cheolhee Kim, Sung Yi

Mechanical and Materials Engineering Faculty Publications and Presentations

Fused deposition modeling (FDM), as one of the additive manufacturing processes, is known for strong layer adhesion suitable for prototypes and end-use items. This study used a multiple regression model and statistical analysis to explore the dimensional accuracy of FDM objects. Factors such as inclination angle, layer thickness, support space, and raster angle were examined. Machine learning models (Gaussian process regression (GPR), support vector machines (SVM), and artificial neural network (ANN)) predicted dimensions using 81 datapoints. The mean squared dimensional error (MSDE) between the measured and designed surface profiles was selected as an output for the dimensional accuracy. Support spacing, …

Localization And Shape Determination Of A Hidden Corridor In The Great Pyramid Of Giza Using Non-Destructive Testing, Mohamed Elkarmoty, Johannes Rupfle, Khalid Helal, Mohamed Sholqamy, Mohamed Fath-Elbab, Jochen Kollofrath, Thomas Schumacher, Multiple Additional Authors

Civil and Environmental Engineering Faculty Publications and Presentations

Built over 4500 years ago, the Great Pyramid of Giza, Egypt, is the only remaining structure of the Wonders of the Ancient World as described by the ancient Greek historian Herodotus. Despite this long existence, only recently has modern science and technology been employed to study this massive stone structure. Cosmic-ray muon radiography throughout the ScanPyramids project has detected a large void above the Grand Gallery of the Great Pyramid and a smaller unidentified void behind the so-called Chevron. The Chevron is an assembly of four large limestone blocks arranged in the shape of two inverted downward open angles. Guided …

Investigating Evidence In Support Of Validity And Reliability For Data Collected With The Meaningful Learning In The Laboratory Instrument (Mlli), Elizabeth Vaughan, A. Montoya-Cowan, Jack Barbera

Chemistry Faculty Publications and Presentations

The Meaningful Learning in the Laboratory Instrument (MLLI) was designed to measure students’ expectations before and after their laboratory courses and experiences. Although the MLLI has been used in various studies and laboratory environments to investigate students’ cognitive and affective laboratory expectations, the authors of the instrument reported a discrepancy between the intended factor structure of the MLLI and the factor structure suggested by the data collected in preliminary studies. Therefore, the aim of this study was to investigate the validity and reliability evidence related to data collected with the MLLI, especially that related to structural validity. Evidence to support …

Auxiliary Features-Guided Super Resolution For Monte Carlo Rendering, Qiqi Hou, Feng Liu

Computer Science Faculty Publications and Presentations

This paper investigates super-resolution to reduce the number of pixels to render and thus speed up Monte Carlo rendering algorithms. While great progress has been made to super-resolution technologies, it is essentially an ill-posed problem and cannot recover high-frequency details in renderings. To address this problem, we exploit high-resolution auxiliary features to guide super-resolution of low-resolution renderings. These high-resolution auxiliary features can be quickly rendered by a rendering engine and at the same time provide valuable high-frequency details to assist super-resolution. To this end, we develop a cross-modality transformer network that consists of an auxiliary feature branch and a low-resolution …

Accelerating Training Of Mlips Through Small-Cell Training, Jason A. Meziere, Yu Luo, Yi Xia, Laurent Karim Béland, Mark R. Daymond

Mechanical and Materials Engineering Faculty Publications and Presentations

While machine-learned interatomic potentials have become a mainstay for modeling materials, designing training sets that lead to robust potentials is challenging. Automated methods, such as active learning and on-the-fly learning, construct reliable training sets, but these processes can be resource-intensive. Current training approaches often use density functional theory (DFT) calculations that have the same cell size as the simulations that the potential is explicitly trained to model. Here, we demonstrate an easy-to-implement small-cell training protocol and use it to model the Zr-H system. This training leads to a potential that accurately predicts known stable Zr-H phases and reproduces the α-β …

Forest Fire Effects On Snow Storage And Melt Across Scales Of Forest Recovery In The Western Oregon Cascades, Megan Nicole Guinn

Dissertations and Theses

Snow is the largest component of water storage in the western United States, it serves as a key moisture source for forested ecosystems and is fundamentally linked to streamflow and nutrient cycling. Snow is vulnerable to climatic warming, and a key consequence of declining mountain snowpack is the escalation in wildfire frequency, extent, intensity, and duration across the seasonal snow zone. Fire modifies the spatial extent of snow in watersheds, reducing snow water storage and timing of melt across burned forests. Forested mountain ecosystems and water supplies are facing shifts in their structure, function, and succession. Previous research has focused …

Love Letters For Liberatory Futures, Jessica Rodriguez-Jenkins, Roberta Hunte, Lakindra Mitchell Dove, Antonia R.G. Alvarez, Alma M. O. Trinidad, Gita Mehrotra

School of Social Work Faculty Publications and Presentations

This collection of letters serves to explore the narratives of a collective of women of color in academia by examining individual, collective, spiritual, and institutional strategies for surviving and transforming our institutional spaces and the ways that White Supremacy has shaped our journeys. Multiple perspectives are viewed, and we have written to our children, our future social work students, our future selves, our BIPOC faculty siblings, and our feared enemies to envision and embody more liberatory futures.

Keywords: liberation, academia, BIPOC faculty, institutional racism, White Supremacy

Modeling Leaf-Level Transpiration: Exploring The Consequences Of Assumed Saturated Vapor Pressure In Leaves, Danlyn L. Brennan

Dissertations and Theses

Understanding the dynamics of water transport through leaf intercellular airspaces (IAS) and its impact on transpiration is crucial for accurate predictions of plant water use and ecosystem response to changing climates. This study investigates the implications of assuming undersaturation of water vapor in the IAS for transpiration predictions and explores potential modifications to standard modeling approaches.

A dynamic 1D soil-plant-atmosphere continuum using a stomatal optimization model (SPAC-SOT) framework was used to simulate the response of tree species, P. edulis, to prolonged drought and varying environmental conditions. Comparisons between two model assumptions (saturated vs. undersaturated IAS) reveal notable differences in …

Design And Characterization Of 2.4ghz Antennas For Wireless Sensor Applications, Luis Zogby Brennan

Dissertations and Theses

Wireless sensor networks benefit greatly from advances in circuit integration and miniaturization. However, antennas are bound to specific geometries both in terms of fundamental limits and their response to immediate surroundings. As such, various successful techniques for antenna miniaturization must still be carefully tested and characterized as part of the design process of a sensor system. The work presented here fully characterizes a number of miniaturized 2.4GHz antennas and successfully integrates designs into a sensor system using the highly integrated Single Chip Micro Mote (SCµM), which uses a crystal-less radio design resulting in the requirement of only a …

Left Out To Dry: Understanding The Social Experiences Of Ground Depletion In Washington State's Columbia River Basin, Alexis Lisandro Guizar-Diaz

Dissertations and Theses

Millions of water wells worldwide risk running dry due to overpumping, drought, and climate change. This study adopts a political ecology framework to investigate how economic structures and power dynamics shape the effects of groundwater depletion in a highly impacted region. It is based on qualitative fieldwork conducted in the Odessa Aquifer region of Washington State. This agriculturally productive region has experienced severe groundwater depletion, endangering communities and threatening water supplies for many, as agribusiness has intensively used deep water wells to irrigate high-value crops. This research addresses three key questions: 1) How do residents and households excluded from irrigation …

Not On The Menu: Customer Sexual Harassment In The Restaurant Industry, Fernanda Wolburg Martinez

Dissertations and Theses

Despite the high prevalence of customer sexual harassment (CSH) paired with a high turnover in the restaurant industry, there have been few suggestions on resources that may attenuate the effect that bystander and direct CSH might have on strain--anxiety and depressive symptoms--and turnover intentions among restaurant workers. Based on the stipulations of the job-demands resources theory and the empowerment framework, the current study frames direct and bystander CSH as job demands that may be linked to employee strain and turnover intentions. Moreover, CSH preventive supervisor behaviors and organizational intolerance towards CSH are introduced as job resources that may weaken the …

The Influence Of Polystyrene Microplastics On Juvenile Steelhead Trout (Oncorhynchus Mykiss), Kaitlyn Marie Baker

Dissertations and Theses

Mass production of plastic within the past decade has led to over 100 billion tons of plastics being added to the world’s oceans through rivers and effluent disposal and decomposition. For marine environments, the sudden and constant growth of microplastics (plastics 1 µm to 5 mm in diameter), is of particular concern to top-predatory fish such as steelhead trout (Oncorhynchus mykiss), who passively or actively uptake microplastics while consuming prey. Previous research has demonstrated clear detrimental impacts of microplastic accumulation in bivalves, seabirds, and zebrafish, including decreased diet, reproduction rates, and metabolism, as well as increased rates of …

Instructors At A Crossroad: Perceptions Of Collaboration And Support Intersect With Intentions To Implement A Cure, Justin Berl

Dissertations and Theses

An ongoing crisis of student drop-off from undergraduate science, technology, engineering and mathematics (STEM) education has led to a sustained call over the last 15+ years for the increased implementation of updated practices in undergraduate STEM education. Though over the past few decades many researchers have developed and analyzed the efficacy of various evidence-based teaching practices (EBTPs) designed to improve the state of undergraduate STEM education throughout the country, the rate at which these EBTPs are implemented in undergraduate STEM classrooms remains low.

In order to better understand the specific factors that affect individual instructors' efforts to implement EBTPs, we …

Similarities, Commonalities And Parallels In The Contributions Of Thorstein Veblen And Friedrich Nietzsche, John B. Hall

Economics Faculty Publications and Presentations

This inquiry seeks to establish that similarities, commonalities, and parallels can be identified in selected contributions advanced by Thorstein Veblen and Friedrich Nietzsche. In the main, their commonness is noted to appear in the critical approaches that also includes expressing deep-seated skepticism regarding the course to modernity, singling out institutions ruling society, and especially the economy—in the case of Veblen. Specialized in Philology, as Nietzsche extolls his Dionysian orientation this inquiry introduces the idea that Veblen’s foundation for his distinctly critical approach to ruling institutions also reflects a Dionysian perspective. In Thus Spoke Zarathustra (1883-85) Nietzsche introduces a character whom …

Structure-From-Motion Derived Snow Cover In Burned Forests Of The Western Oregon Cascades, Siobhan Ciafone

Dissertations and Theses

Forest fire occurrence in the western US has increased rapidly since the 1980s, and most western US fires occur in the seasonal snow zone. Burned forests influence snow accumulation and melt patterns for years following fire, and understanding drivers of variability in snow cover across a burned landscape at the basin-scale is necessary for accurate hazard prediction and water resource forecasting. Basin-scale surveys of snowpack are possible with remote sensing, but accurate sensing methods such as Light Detection and Ranging (LiDAR) are often cost-prohibitive. In the last decade, structure-from-motion (SfM), an optical remote sensing technique, has emerged as an affordable …

Race And Income As Predictors Of Trust In Flood Mitigation Strategies, Wendy Nathaly Sangucho Loachamin

Dissertations and Theses

Trust plays a central role in coastal flooding management because the support or opposition to costly mitigation strategies depends, in part, on how much stakeholders trust in the effectiveness of these strategies. Despite the importance of trust in the approval of flood mitigation strategies, trust is rarely measured. Furthermore, Environmental Justice (EJ) studies have consistently shown that BIPOC (Black, Indigenous and People of Color) and low-income communities are more vulnerable to environmental hazards. Therefore, if these communities are more exposed to flooding, we hypothesize they will have less trust in flood mitigation strategies to protect them; yet trust is understudied …

Optimally Distributed Receiver Placements Versus An Environmentally Aware Source: New England Shelf Break Acoustics Signals And Noise Experiment, William K. Stevens, Martin Siderius, Matthew J. Carrier, Drew Wendeborn

Electrical and Computer Engineering Faculty Publications and Presentations

This article describes the results of the Spring of 2021 New England Shelf Break Acoustics (NESBA) Signals and Noise experiment as they pertain to the optimization of a field of passive receivers versus an environmentally aware source with end-state goals. A discrete optimization has been designed and used to demonstrate providing an acoustic system operator with actionable guidance relating to optimally distributed receiver locations and depths and likely mean source detection times and associated uncertainties as a function of source and receiver levels of environmental awareness. The uncertainties considered here are those due to the imperfect spatial and temporal sensing …

Evaluation Of Driver Comprehension And Compliance Of Red Colored Pavement Markings For Transit Lanes In Portland, Oregon, Nathan Mcneil, Christopher Monsere, Jennifer Dill

Urban Studies and Planning Faculty Publications and Presentations

Many U.S. agencies have experimented with red colored pavement markings in transit lanes to enhance the message that they are restricted to transit vehicles. This study evaluates non-transit drivers’ comprehension of and compliance with red colored lane markings in transit priority lanes intended to communicate lane restrictions and appropriate turning and merging locations. Two complementary research methods were used: 1) an online survey of drivers’ comprehension of red colored pavement markings; and, 2) evaluation of video collected at locations pre and post installation of red colored pavement markings. In the survey, most drivers recognize the red pavement color as a …

Role Of Binder On Yield Strength Of Polycaprolactone/Dimethylsulfone Composites For Bio-Applications, Kyung-Eun Min, Jae-Won Jang, Sung Yi, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Polycaprolactone (PCL) and dimethylsulfone (DMSO2) composites can tailor the properties of scaffold materials, allowing their use in bone tissue engineering. With an increase in DMSO2 content, the modulus of the material increases but not the yield strength. In order to increase yield strength, a binder was added. However, the optimization of the content and the mixing process of the binder were not optimized in the previous studies. In this study, gamma-methacryloxypropyltrimethoxysilane (A-174) was used as a binder to increase the strength of a composite. Four different mixing processes were employed based on the binder mixing sequence. The binders with content …

Modeling Yield Strength Of Austenitic Stainless Steel Welds Using Multiple Regression Analysis And Machine Learning, Sukil Park, Myeonghwan Choi, Dongyoon Kim, Cheolhee Kim, Namhyun Kang

Mechanical and Materials Engineering Faculty Publications and Presentations

Designing welding filler metals with low cracking susceptibility and high strength is essential in welding low-temperature base metals, such as austenitic stainless steel, which is widely utilized for various applications. A strength model for weld metals using austenitic stainless steel consumables has not yet been developed. In this study, such a model was successfully developed. Two types of models were developed and analyzed: conventional multiple regression and machinelearning- based models. The input variables for these models were the chemical composition and heat input per unit length. Multiple regression analysis utilized five statistically significant input variables at a significance level of …

Asymmetric Secondary Flows Above Geometrically Symmetric Surface Roughness, Wen Zhang, Xiang Yang, Xiaowei Zhu, Minping Wan, Shiyi Chen

Mechanical and Materials Engineering Faculty Publications and Presentations

The mean flow behaviour of a turbulent boundary layer over rough walls is expected to exhibit symmetries that govern the flow dynamics. In particular, when roughness elements are arranged in a spanwise symmetric manner, the mean flow above them should also exhibit spanwise symmetry. This symmetrical consideration has garnered substantial empirical support. We conduct direct numerical simulations (DNS) of flow over aligned cube arrays to test such symmetry considerations further. We vary the surface coverage density from 0.25 % to 6.25 %, and employ an averaging time of about 100 large-eddy turnover times, which is longer than the typical averaging …

Real-Time Length Sensing Of Braided Pneumatic Actuator Using Ir Time-Of-Flight Sensor, Luon B. Chung

Dissertations and Theses

Braided Pneumatic Actuators (BPAs) are used widely in robotics as artificial muscles because of their similar characteristics to biological muscles. When a BPA is pressurized, it expands in the radial direction and contracts in the longitudinal direction. The contraction generates a pulling force that is dependent on the input pressure and BPA length. Biological muscle also behaves in the same way where a pulling force is generated on a contraction. To control BPAs on a robot, the real-time pressure and length measurements are necessary. In this dissertation, I present a new method to measure length of BPAs in real-time using …

Multi-Agent Deep Reinforcement Learning For Radiation Localization, Benjamin Scott Totten

Dissertations and Theses

For the safety of both equipment and human life, it is important to identify the location of orphaned radioactive material as quickly and accurately as possible. There are many factors that make radiation localization a challenging task, such as low gamma radiation signal strength and the need to search in unknown environments without prior information. The inverse-square relationship between the intensity of radiation and the source location, the probabilistic nature of nuclear decay and gamma ray detection, and the pervasive presence of naturally occurring environmental radiation complicates localization tasks. The presence of obstructions in complex environments can further attenuate the …