Digital Commons Network^™

A Novel Data Fusion Fr Amework To Enhance Contextual Awareness Of The Autonomous Vehicles For Accurate Decision Making, Henry Alexander Ignatious

Dissertations

Autonomous driving has the potential to bring significant changes and benefits to various aspects of transportation. Autonomous vehicles (AVs) use a combination of advanced sensors, cameras, radar, lidar, GPS, maps, and AI algorithms to perceive their environment, make decisions, and control their movements. Though there is a significant increase in the AVs utility, there are several challenges associated with the AVs among which ensuring safety and security for a reliable drive is still an existing challenge. The majority of accidents involving the AVs result from faulty decision-making resulting in fatal incidents. Multiple elements contribute to the flawed decision-making in autonomous …

Limonene Enantiomeric Ratios From Anthropogenic And Biogenic Emission Sources, Shan Gu, Wentai Luo, Avisa Charmchi, Kevin J. Mcwhirter, Todd Rosenstiel, James F. Pankow

Chemistry Faculty Publications and Presentations

Emissions from volatile chemical products (VCPs) have been identified as contributors to air quality degradation in urban areas. Limonene can be a tracer compound for VCPs containing fragrances in densely populated regions, but limonene is also emitted from conifers that are planted in urban areas. This creates challenges for using limonene to estimate VCP emissions. In this study, the −/+ enantiomeric ratios of limonene from VCP and conifer emission sources were quantified to evaluate if this measurement could be used to aid in source apportionment and emission inventory development. Samples were analyzed using a gas chromatograph equipped with a chiral …

Using Flipped Classroom Modules To Facilitate Higher Order Learning In Undergraduate Organic Chemistry, Lauren R. Holloway, Tabitha Miller, Bryce Da Camara, Paul M. Bogie, Briana L. Hickey, Jack Barbera, Angie L. Lopez, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

In an ongoing effort to incorporate active learning and promote higher order learning outcomes in undergraduate organic chemistry, a hybrid (“flipped”) classroom structure has been used to facilitate a series of collaborative activities in the first two courses of the lower division organic chemistry sequence. An observational study of seven classes over a five-year period reveals there is a strong correlation between performance on the in-class activities and performance on the final exam across all classes; however, a significant number of students in these courses continue to struggle on both the in-class activities and final exam. The Activity Engagement Survey …

Comprehensive Numerical Modeling Of Prestressed Girder Bridges Under Low-Velocity Impact, Mohamed T. Elshazli, Mohanad M. Abdulazeez, Mohamed Elgawady, Ahmed Ibrahim

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Accidental Collisions Involving Over-Height Trucks That Exceed Vertical Clearance Limits And Bridge Superstructures Frequently Happen, Resulting In Compromised Girders And Potential Threats To Structural Safety And Performance. The Numerical Simulation Of Large-Scale Prestressed Girder Bridge Collisions Poses Challenges Due To The Associated Nonlinearities, As Well As The Limited Availability Of Large-Scale Experimental Testing Data In The Literature Due To Cost And Complexity Constraints. This Study Introduces A Numerical Modeling Approach To Efficiently Capture The Response Of Prestressed Girder Bridges Under Lateral Impact Loads. A Finite Element (FE) Model Was Developed Using LS-DYNA And Meticulously Validated Against Experimental Data From The …

Natural Gas Induced Vegetation Stress Identification And Discrimination From Hyperspectral Imaging For Pipeline Leakage Detection, Pengfei Ma, Ying Zhuo, Genda Chen, Joel G. Burken

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Remote Sensing Detection of Natural Gas Leaks Remains Challenging When using Ground Vegetation Stress to Detect Underground Pipeline Leaks. Other Natural Stressors May Co-Present and Complicate Gas Leak Detection. This Study Explores the Feasibility of Identifying and Distinguishing Gas-Induced Stress from Other Natural Stresses by Analyzing the Hyperspectral Reflectance of Vegetation. the Effectiveness of This Discrimination is Assessed Across Three Distinct Spectral Ranges (VNIR, SWIR, and Full Spectra). Greenhouse Experiments Subjected Three Plant Species to Controlled Environmental Stressors, Including Gas Leakage, Salinity Impact, Heavy-Metal Contamination, and Drought Exposure. Spectral Curves Obtained from the Experiments Underwent Preprocessing Techniques Such as Standard …

Technical Note: Generalizable And Promptable Artificial Intelligence Model To Augment Clinical Delineation In Radiation Oncology, Lian Zhang, Zhengliang Liu, Lu Zhang, Zihao Wu, Xiaowei Yu, Jason Holmes, Hongying Feng, Haixing Dai, Xiang Li, Quanzheng Li, William W. Wong, Sujay A. Vora, Dajiang Zhu, Tianming Liu, Wei Liu

Computer Science Faculty Research & Creative Works

Background: Efficient and accurate delineation of organs at risk (OARs) is a critical procedure for treatment planning and dose evaluation. Deep learning-based auto-segmentation of OARs has shown promising results and is increasingly being used in radiation therapy. However, existing deep learning-based auto-segmentation approaches face two challenges in clinical practice: generalizability and human-AI interaction. A generalizable and prompt able auto-segmentation model, which segments OARs of multiple disease sites simultaneously and supports on-the-fly human-AI interaction, can significantly enhance the efficiency of radiation therapy treatment planning. Purpose: Meta's segment anything model (SAM) was proposed as a generalizable and prompt able model for next-generation …

Inverting Geodetic Strain Rates For Slip Deficit Rate In Complex Deforming Zones: An Application To The New Zealand Plate Boundary, Kaj M. Johnson, Laura M. Wallace, Jeremy Maurer, Ian Hamling, Charles Williams, Chris Rollins, Matt Gerstenberger, Russ Van Dissen

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The potential for future earthquakes on faults is often inferred from inversions of geodetically derived surface velocities for locking on faults using kinematic models such as block models. This can be challenging in complex deforming zones with many closely spaced faults or where deformation is not readily described with block motions. Furthermore, surface strain rates are more directly related to coupling on faults than surface velocities. We present a methodology for estimating slip deficit rate directly from strain rate and apply it to New Zealand for the purpose of incorporating geodetic data in the 2022 revision of the New Zealand …

Assessment Of The Impact Of Humic Acids On Intestinal Microbiota, Gut Integrity, Ileum Morphometry, And Cellular Immunity Of Turkey Poults Fed An Aflatoxin B1-Contaminated Diet, Jesus A. Maguey-Gonzalez, Jing Liu, Guolong Zhang, Juan D. Latorre, Juan O. Hernandez-Ramirez, Maria De Jesus Nava-Ramirez, Roberto Señas-Cuesta, Sergio Gomez-Rosales, Maria De Lourdes Angeles, Andressa Stein, Bruno Solis-Cruz, Daniel Hernandez-Patlan, Ruben Merino-Guzman, Xochitl Hernandez-Velasco, Inkar Castellanos-Huerta, Santiago Uribe-Diaz, Alma Vazquez-Duran, Abraham Mendez-Albores, Victor Petrone-Garcia, Guillermo Tellez Jr., Billy M. Hargis, Guillermo Tellez-Isaias

Poultry Science Faculty Publications and Presentations

A recent study published data on the growth performance, relative weights of the organs of the gastrointestinal tract, liver histology, serum biochemistry, and hematological parameters for turkey poults fed an experimental diet contaminated with aflatoxin B₁ (AFB₁) and humic acids (HA) extracted from vermicompost. The negative effects of AFB₁ (250 ng AFB₁/g of feed) were significantly reduced by HA supplementation (0.25% w/w), suggesting that HA might be utilized to ameliorate the negative impact of AFB₁ from contaminated diets. The present study shows the results of the remaining variables, as an extension of …

Generative Ai In Finance: Risks And Potential Solutions, Nydia Remolina Leon

Research Collection Yong Pung How School Of Law

Generative Artificial Intelligence captured the attention of academics, policymakers, the private sector, and some regulators in 2022 after the launch of ChatGPT and its widespread adoption worldwide. Then, during the World Economic Forum session in 2023, Microsoft Chairman and Chief Executive Officer Satya Nadella said that the ‘golden age’ of AI is underway and generative AI is set to play a big role in it. Accordingly, Microsoft has invested billions of dollars into OpenAI, the company behind the launch of ChatGPT. Additionally, Google and Meta have also created their own generative AI models. Given the multiplicity of potential use cases …

Dna-Based Assay For Calorimetric Determination Of Protein Concentrations In Pure Or Mixed Solutions, Matthew W. Eskew, Patrick Reardon, Albert S. Benight

Chemistry Faculty Publications and Presentations

It was recently reported that values of the transition heat capacities, as measured by differential scanning calorimetry, for two globular proteins and a short DNA hairpin in NaCl buffer are essentially equivalent, at equal concentrations (mg/mL). To validate the broad applicability of this phenomenon, additional evidence for this equivalence is presented that reveals it does not depend on DNA sequence, buffer salt, or transition temperature (Tm). Based on the equivalence of transition heat capacities, a calorimetric method was devised to determine protein concentrations in pure and complex solutions. The scheme uses direct comparisons between the thermodynamic stability of a short …

Collaborative Fisheries Research Reveals Reserve Size And Age Determine Efficacy Across A Network Of Marine Protected Areas, Shelby L. Ziegler, Rachel O. Brooks, Lyall F. Bellquist, Jennifer E. Caselle, Steven G. Morgan, Timothy J. Mulligan, Benjamin I. Ruttenberg, Brice X. Semmens, Richard M. Starr, Joe Tyburczy, Dean E. Wendt, Andre Buchheister, Jose R.Marin Jarrin, Christina Pasparakis, Salvador J. Jorgensen, Jennifer A. Chiu, Jordan Colby, Connor L. Coscino, Leon Davis

Faculty Research, Scholarly, and Creative Activity

A variety of criteria may influence the efficacy of networks of marine protected areas (MPA) designed to enhance biodiversity conservation and provide fisheries benefits. Meta-analyses have evaluated the influence of MPA attributes on abundance, biomass, and size structure of harvested species, reporting that MPA size, age, depth, and connectivity influence the strength of MPA responses. However, few empirical MPA evaluation studies have used consistent sampling methodology across multiple MPAs and years. Our collaborative fisheries research program systematically sampled 12 no-take or highly protective limited-take MPAs and paired fished reference areas across a network spanning 1100 km of coastline to evaluate …

Mask2former With Improved Query For Semantic Segmentation In Remote-Sensing Images, Shichen Guo, Qi Wang, Shiming Xiang, Shuwen Wang, Xuezhi Wang

Computer Science Faculty Publications and Presentations

Semantic segmentation of remote sensing (RS) images is vital in various practical applications, including urban construction planning, natural disaster monitoring, and land resources investigation. However, RS images are captured by airplanes or satellites at high altitudes and long distances, resulting in ground objects of the same category being scattered in various corners of the image. Moreover, objects of different sizes appear simultaneously in RS images. For example, some objects occupy a large area in urban scenes, while others only have small regions. Technically, the above two universal situations pose significant challenges to the segmentation with a high quality for RS …

Editorial: Innovating A New Knowledge Base For Water Justice Studies: Hydrosocial, Sociohydrology, And Beyond, Melissa Haeffner, Jenia Mukherjee, Rebecca Lave, Jamie Linton, John Ndiritu, Raul Pacheco-Vega, Maria Ruska, Margreet Zwarteveen

Environmental Science and Management Faculty Publications and Presentations

Creating a new knowledge base that centers water justice (Zwarteveen and Boelens, 2014; Sultana, 2018; Wölfle-Hazard, 2022) in hydrosocial and sociohydrology studies involves a broader discussion about why justice matters, how to work toward this goal, and what the implications for research praxis are. The articles in this Research Topic approach different angles of water justice: as law (Fernández and Alba), a social movement (Dame et al.), practice (Pool et al.; Reeves and Bonney), cases of injustice (Caretta et al.), and theory (Krueger and Alba). From this Research Topic, we find that the interrelated concepts of naturecultures and care can …

Reconnecting A Stream Channel To Its Floodplain: Implications For Benthic Diatoms And Macroinvertebrate Trophic Structure, Patrick M. Edwards, Nicole C. Popp, Yangdong Pan, Christine L. Weilhoefer, Aspen Peterman, Lauren Mork, Matthew F. Johnson, Megan Colley, Multiple Additional Authors

Environmental Science and Management Faculty Publications and Presentations

Streams systems draining upland landscapes provide valuable ecosystem services, but they are vulnerable to incision and channelization caused by anthropogenic disturbance. Restoring a degraded stream to its pre-disturbance condition by reconnecting the channel to its historical floodplain aims to recover lost hydro-morphological processes and functions. Seeking evidence to indicate whether that aim is met in practice, we examined diatoms and the stream macroinvertebrate trophic structures in three reaches of Whychus Creek, Oregon, United States. Two reaches were reconnected to their pre-disturbance floodplains in 2012 and 2016. The third, control reach, was not restored and was selected to represent the degraded …

Novel Avenues Of Tau Research, Claire E Sexton, Gal Bitan, Kathryn R Bowles, Miroslaw Brys, Luc Buée, Mahmoud Bukar Maina, Claire D Clelland, Ann D Cohen, John F Crary, Jeffrey L Dage, Kristophe Diaz, Bess Frost, Li Gan, Alison M Goate, Lawrence I Golbe, Oskar Hansson, Celeste M Karch, Hartmuth C Kolb, Renaud La Joie, Suzee E Lee, Diana Matallana, Bruce L Miller, Chiadi U Onyike, Yakeel T Quiroz, Jessica E Rexach, Jonathan D Rohrer, Amy Rommel, Ghazaleh Sadri-Vakili, Suzanne E Schindler, Julie A Schneider, Reisa A Sperling, Charlotte E Teunissen, Stacie C Weninger, Susan L Worley, Hui Zheng, Maria C Carrillo

Faculty, Staff and Students Publications

INTRODUCTION: The pace of innovation has accelerated in virtually every area of tau research in just the past few years.

METHODS: In February 2022, leading international tau experts convened to share selected highlights of this work during Tau 2022, the second international tau conference co-organized and co-sponsored by the Alzheimer's Association, CurePSP, and the Rainwater Charitable Foundation.

RESULTS: Representing academia, industry, and the philanthropic sector, presenters joined more than 1700 registered attendees from 59 countries, spanning six continents, to share recent advances and exciting new directions in tau research.

DISCUSSION: The virtual meeting provided an opportunity to foster cross-sector collaboration …

What Explains Male And Female Decision Making To Enter Law? Evidence From A Survey Of Us-Based Undergraduate Students, Abigail Cohen

University Honors Theses

The research conducted in this thesis aims to explain why fewer females than males choose law and pinpoint the explanation as to why they have disparate experiences in the field. The hypothesis is sex discrimination is to blame for the differences among female and male decision making. Sexual harassment and discrimination plays a very prominent role in male dominated fields and discourages females from joining those workforces. The research method for this experiment was an anonymous survey, sent out via social media and email. The survey method was chosen because it was meant to be a quick, yet effective way …

Small Unmanned Aircraft System Detection And Tracking With Audio, Computer Vision, And Deep Learning Techniques, Anthony C. Brunson

Theses and Dissertations

sUAS present significant risks to local and federal agencies when under the control of negligent, reckless, or criminal operators. In the face of an escalating presence of sUAS in shared airspace with traditional aircraft, and their deployment in protected airspace as potential weapons, safeguarding personnel, facilities, and assets becomes paramount. This research seeks to address this emerging threat by investigating the efficacy of integrating low-cost distributed sensors and Machine learning (ML) models to enhance battlespace awareness and complement existing sensing platforms for real-time sUAS detection, classification, and localization. The thesis introduces the conceptualization and development of a Drone Detection Command …

Performance Of Humans And Agents In A Systems Modeling Language V2 Task: A User-Centered Evaluation Approach, Allen W. Dukes

Theses and Dissertations

The Department of Defense is adopting Digital Engineering practices for its workforce. Simultaneously, the larger Systems Engineering community strives to modernize and define those Digital Engineering practices. These efforts to move from traditionally document-based approaches to pure digital implementations will require enhanced capabilities to manage and digitally track the lifecycle of a program or product. However, this growth must address tool design through an iterative process focusing on usability for many user types. Many tools and technologies exist but often lack an assessment of usability when engineers design tools for other engineers. Including usability when developing solutions for Digital Engineering …

Trajectory Optimization Via Direct Collocation Methods Of Boost-Glide Vehicle With Newtonian Aerodynamic Model, Andrew Bonavita

Theses and Dissertations

In this work, a Newtonian aerodynamic model was developed for an elliptic cone glide geometry at a variety of angles of attack, and a functional relationship between an input angle of attack and the vehicle lift and drag coefficients was developed. This model was used in a direct orthogonal collocation framework to simulate a series of boost-glide trajectories, with objectives of minimum distance to target, minimum time to target, and maximum velocity to target. The optimal control problem was then expanded into a reachability study, considering a wide range of additional scenarios, along with studies on the vehicle range capabilities. …

Rapid Passive Safety Determination Using Backward Reachability For Spacecraft Rendezvous And Proximity Operations, Kealy A. Murphy

Theses and Dissertations

As the prevalence of autonomous space systems rise, there is an urgent demand for robust and precise safety analysis. The future of RPO necessitates coordination of satellites in a dynamic and congested space environment while avoiding collisions. Passive safety in RPO refers to the implementation of strategies that minimize the collision risk in the event of orbital or control deviations. This multifaceted problem includes maintaining KOZ, utilizing predictive modeling to anticipate collision scenarios, and designing spacecraft with robust GNC systems allowing for timely course corrections. The current literature’s focus has been on the separation distance between spacecraft as a primary …

Evasion Strategies For Space Engagements With Unknown Pursuer Objectives, Stephanie L. Halsey

Theses and Dissertations

Realistic simulations provide a tool for operators to understand space tactics and also serve to inform decisions on the requirements of current spacecraft technologies. This research uses simulation to gain a better understanding of one-on-one orbital conflicts through orbital differential games and linear quadratic games. The results of this research find that a simple strategy for an evading spacecraft to successfully evade a more-capable pursuing satellite for a variety of potential goals is to thrust perpendicular to the direction of the pursuer. Specific estimation requirements to accurately determine the objective of the pursuer and successfully evade in a realistic scenario …

Influence Of Environmental Barrier Coatings On The Overall Effectiveness Of A Film Cooled Ceramic Matrix Composite Plate, Shane P. Lindsay

Theses and Dissertations

Silicon carbide ceramic matrix composites, a promising new potential upgrade over the conventional metals currently used for jet engine turbine blades, have a propensity to oxidize in a combustion environment. Engine manufacturers often apply environmental barrier coatings to prevent the composites from oxidizing. What is unclear, however, is how environmental barrier coatings effect underlying composite temperatures. This research examined the coatings’ effects by first characterizing the influence of environmental barrier coatings on the underlying temperature of a protected ceramic, then evaluating the significance of lateral conduction for cooling a coated ceramic, and finally comparing cooling results for coated and uncoated …

Origami Application And Attitude Control Investigation Of Space-Based Mirror System, David J. Garcia

Theses and Dissertations

Imaging and inspecting Resident Space Objects (RSO) have gained increasing importance in Space Situational Awareness (SSA) missions. These missions are driven by the necessity to perform satellite repairs, refueling, de-orbiting, and orbital debris reduction. However, the challenging lighting conditions in space often hinder these tasks. To overcome this challenge, a novel concept has been proposed—deploying mirrors from servicer satellites. These mirrors would harness solar energy to illuminate dimly-lit RSOs, enabling imaging, inspection, repair, and refueling operations. In this context, servicer satellites play a pivotal role in controlling the reflected light beam and precisely positioning themselves to illuminate RSOs effectively. Notably, …

Preliminary Assessment Of Cislunar Disposal Orbits, Ryan M. Sargent

Theses and Dissertations

This thesis investigates the disposal of end-of-life spacecraft from key orbits with a focus on minimizing delta-v expenditure and preventing debris propagation. Simulated Lyapunov and halo orbits around the L2 Lagrange point are analyzed for disposal feasibility. Both impulsive and continuous thrust methods are explored to achieve disposal trajectories. Continuous thrust will be modeled after a Hall thruster utilizing electric propulsion. Leveraging the Circular Restricted Three Body Problem framework, low delta-v cost trajectories are computed, with a multi-level correction algorithm optimizing total delta-v via heteroclinic connections. The study assesses various delta-v amounts for Earth-Moon system escape and evaluates the potential …

Forecasting Stock Prices Using Arima Models And Technical Analysis, Muath I. Almaiman

Theses and Dissertations

This thesis explores the integration of Autoregressive Integrated Moving Average (ARIMA) models and technical analysis to forecast stock prices, with a focus on Coca-Cola's (KO) and Netflix’s (NFLX) stocks. It examines the effectiveness of combining ARIMA models, known for their predictive accuracy in time-series analysis, with technical indicators, particularly moving averages. The study evaluates whether this integrated approach can enhance the predictive capability of stocks prices beyond traditional methods. The predictive capability is evaluated using error metrics from the ARIMA models, as well as by assessing the return earned using simple rules based on the technical indicators. Utilizing data spanning …

Housing Preferences And Vertical Expansion Potential In Riyadh City, Nasser R. Alrashed

Theses and Dissertations

This research investigates the demand for apartment living in Riyadh's northern area and assesses its implications for vertical urban development, aligning with Saudi Arabia's Vision 2030. Employing a quantitative methodology, a structured survey was distributed to a diverse cross-section of Riyadh's population, focusing on housing preferences and perceptions of vertical living. Key findings indicate a significant demand for apartments, primarily from young to middle-aged, smaller households in low to middle-income brackets. Notably, a substantial portion of respondents showed a preference for high-rise living, suggesting a readiness for vertical expansion to manage the city's growing population. The study concludes that Riyadh's …

3F4 Hypergeometric Functions As A Sum Of A Product Of 2F3 Functions, Jack C. Straton

Physics Faculty Publications and Presentations

This paper shows that certain ₃F₄ hypergeometric functions can be expanded in sums of pair products of ₂F₃ functions, which reduce in special cases to ₂F₃ functions expanded in sums of pair products of ₁F₂ functions. This expands the class of hypergeometric functions having summation theorems beyond those expressible as pair-products of generalized Whittaker functions, ₂F₁ functions, and ₃F₂ functions into the realm of pFq functions where p < q for both the summand and terms in the series. In addition to its intrinsic value, this result has a specific application in calculating the response of the atoms to laser stimulation in the Strong Field Approximation.

Open-Inquiry Opens Doors To Intriguing Optics Experiments At Home: A Case Study, Paul R. Destefano, Ralf Widenhorn

Physics Faculty Publications and Presentations

[This paper is part of the Focused Collection on Instructional labs: Improving traditions and new directions.] This manuscript presents a case study of an introductory physics student who, during the remote learning conditions imposed during the COVID-19 pandemic, found inspiration within a new, openinquiry, project-based, laboratory curriculum designed at Portland State University. The phenomenon investigated by the study subject was intriguing to both the student and the lab instructors for its unfamiliar and instructive optical effect: a ring-shaped pattern or halo created by a laser diffusely reflected in a shallow body of water. Drawing on classwork and interview responses, this …

Enhancing The Resilience Of Space Systems Against Ransomware Attacks, Petersen F. Hansen

Theses and Dissertations

As their relevance has increased in recent years, space systems have become nearly essential in modern life. They are integral in the operation of navigational systems, military operations, and have ushered in a new domain of scientific inquiry. Technological advances have enabled the miniaturization of components and increased the accessibility of satellites as they find new applications in the form of Cube Satellites. However, even as these advancements have brought satellites to new heights, their interconnectedness leaves them open to new cyber threats. Ransomware attacks are one of the most prominent and disruptive cyber threats to terrestrial systems, and while …

Characterization Of An Omega Type Bi-Anisotropic Material, Moriel Gindi

Theses and Dissertations

A theory is presented for the extraction of the complete set of material parameters for a bi-anisotropic sample consisting of conductive omega-type particles governed by the mm21′ point-group symmetry. A rectangular-to-square wave-guide can be used to obtain the required measurements by allowing three distinct orientations of the material. The focus of this work is to develop the appropriate theory detailing the derivation of how the material parameters are extracted from the measurements in an analytical methodology that is similar in manner to the well-known Nicolson-Ross-Weir (NRW) algorithm.