Digital Commons Network^™

Charting The Martian Future: Long-Term Space Policy Planning Of Nasa’S Human Spaceflight Program, 1957-1988, Angel J. Peralta

Electronic Theses and Dissertations

From the late 1950s to the early 1990s, NASA’s human spaceflight programs repeatedly encountered political and bureaucratic pressures that prioritized short-term interests over long-term planning. These constraints shaped the development of the Apollo, Space Shuttle, Space Station, and other human spaceflight programs, limiting NASA’s ability to pursue a sustained strategic vision. This thesis traces the evolution of long-term human spaceflight policy through documents and memos produced by advisory committees, research councils, and key individuals during this period. Despite shifting administrations and their respective politics, these sources reveal a consistent goal of human spaceflight ultimately leading beyond Earth to the Moon …

What Drives Blockchain Technology Adoption? A Meta-Analysis Across Tam, Tpb, And Utaut Frameworks, Amir Rahmani, Roohollah Ahmadi, Tugrul Unsal Daim, Mehdi Zamani, Dilek Ozdemir

Engineering and Technology Management Faculty Publications and Presentations

Research on blockchain adoption has expanded rapidly, with most studies conceptualizing adoption as behavioural intention. Technology adoption models, such as the Technology Acceptance Model (TAM), the Theory of Planned Behavior (TPB), and the Unified Theory of Acceptance and Use of Technology (UTAUT), are commonly applied to explore blockchain technology adoption (BTA). However, empirical results from the 12 hypotheses associated with these models remain fragmented and, at times, inconsistent, with limited comprehensive quantitative integration. To address this gap, the present study performs a meta-analysis to evaluate the degree and direction of these hypotheses systematically. In accordance with PRISMA guidelines, 149 quantitative …

Lessons From The Club Homeschool Capstone: Testing, Data Discipline, And The Computer Science Curriculum, Shane Brown

University Honors Theses

This thesis looks at the CLUB Homeschool Capstone project to argue that Portland State University's Computer Science curriculum should introduce testing and data quality discipline earlier and more intentionally than it does now. As team lead of a seven-person team, I coordinated sprint planning, communicated with the sponsor, and developed custom Discourse plugins that enhanced an existing forum platform instead of creating a separate application database, as requested by the sponsor. The project's requirements document called for a formal testing plan, but our team lacked the practical experience to implement one. This gap became evident through my internships as a …

Ranger Ferdinand Castillo: His Life And Legend, David Carle

Eastern Sierra History Journal

Park Ranger Ferdinand Castillo welcomed visitors to Yosemite National Park from his station at the Tioga Pass gate for 38 years, from 1954 to 1993. The warmth of his greeting, which might include a serenade with his guitar, captivated thousands, a memorable moment. Using hitherto unseen documents and images, David Carle does justice to this public servant.

Managing Inventory In The Supply Chain, Matthew J. Drake

Open Education Materials

Inventory represents a significant investment for most organizations and enables its operations to fulfill customer requirements. Effective inventory management frees critical working capital that the organization can use elsewhere while making sure products and services are available for customers. This book discusses the fundamental concepts of managing inventory within the supply chain and also describes methods for making inventory decisions in a variety of business scenarios.

Evaluating The Motivations Of Participants In Online Equine Extension Courses, Sarah Vos

Department of Animal Science: Dissertations, Theses, and Student Research

Traditional program evaluations emphasize participant demographics, knowledge gain, behavior change, and program impact. However, evaluating participant motivation can provide addition insight into why participants enroll in extension programs and help explain participant engagement and persistence throughout a program. The purpose of this study was to evaluate participant motivation in two online equine extension courses and examine potential relationships between motivation, demographics, and course delivery method, and describe participant engagement in Virtual Horse Judging Camp (VHJC). This cross-sectional study utilized convenience sampling of participants in two online equine extension courses, Horse Adult Leader Training and Educational Resource (HALTER) and VHJC. The …

Iniciativas Transfronterizas Informe De Border Fellows 2025-2026, Elise Free Ma, Tori Luna Ma, Jonathan De Vicente Encarnación Mtro., Yolanda Viridiana Chávez Flores Dra., Korina Odet Cortés Uribe Dra., Jessie Valcin, Cristina Solano Díaz, Etienne Mulumeoderhwa Mufungizi Dr.

Kroc IPJ Research and Resources

El Informe Border Fellows 2025–2026 documenta seis proyectos comunitarios realizados en la región Tijuana–San Diego en el marco del Programa Border Fellows del Kroc Institute for Peace and Justice. Desde la academia, la sociedad civil y el sector público, las y los fellows abordaron retos distintos atravesados por un mismo contexto: el tráfico de armas y la violencia armada contra mujeres y personas LGBTQIA+; la violencia juvenil y el riesgo suicida en una secundaria pública; la discriminación en una preparatoria federal con más de 4,300 estudiantes; la capacidad organizativa y los derechos lingüísticos de comunidades indígenas en Baja California; el …

Cross-Border Initiatives Border Fellow Report 2025-2026, Elise Free Ma, Tori Luna Ma, Jonathan De Vicente Encarnación Ma, Yolanda Viridiana Chávez Flores Phd, Korina Odet Cortés Uribe Edd, Jessie Valcin, Cristina Solano Díaz, Etienne Mulumeoderhwa Mufungizi Phd

Kroc IPJ Research and Resources

The 2025–2026 Border Fellows Report documents six community-led projects carried out across the Tijuana–San Diego region under the Kroc Institute for Peace and Justice's Border Fellows Program. Working in academia, civil society, and the public sector, the fellows addressed distinct challenges shaped by a common context: firearms trafficking and armed violence against women and LGBTQIA+ people; youth violence and suicide risk in a public middle school; discrimination in a federal preparatory school serving more than 4,300 students; the organizational capacity and language rights of Indigenous communities in Baja California; academic accompaniment for Haitian adolescents excluded from formal schooling; and intercultural …

Survival First: How Citizens Prioritize Competing Climate-Health Risk Countermeasures Under Fiscal Constraints, Katsuya Tanaka, Kazuhide Akaishi

Center for Public Service Publications and Reports

When governments must allocate limited resources among competing climate-health countermeasures, citizen risk priorities determine political feasibility—yet whether those priorities translate into fiscal support remains poorly understood. This study develops a hybrid best–worst scaling and contingent valuation framework that integrates individual-level priority parameters into an acceptance model, enabling direct testing of whether preference intensity predicts willingness to pay. Applied to a largesample survey of residents in Yokohama, Japan—a rapidly aging metropolis facing escalating heat emergencies—the analysis reveals three findings. First, citizens exhibit a survival-first hierarchy, decisively prioritizing immediate protective measures over long-term structural interventions, with consensus varying sharply across countermeasure types. …

Staff Education On The Implementation Of An Evidence-Based, Suicide-Risk-Assessment Education Program For Psychiatric Staff, Yemurai Emily Dzikiti

Walden Dissertations and Doctoral Studies

Suicide is a major public health concern, and consistent suicide risk assessment is essential for patient safety in psychiatric settings. This Doctor of Nursing Practice staff education project addressed a knowledge gap in evidence-based suicide risk assessment among psychiatric clinicians in an outpatient mental health setting. The practice-focused question examined whether an evidence-based suicide risk assessment education program would improve clinicians' knowledge from pre- to post-education. The educational intervention consisted of a 60-minute in-person training session on evidence-based suicide risk assessment using the Columbia-Suicide Severity Rating Scale (C-SSRS) and the Suicide Assessment Five-Step Evaluation and Triage (SAFE-T) framework. Ten psychiatric …

August 2026, Office Of Research

Research Update

No abstract provided.

Modulating Linear Frequency Modulated Pulses To Send Communications Data In A Bistatic Sar Scenario, Jarren T. Worthen

All Graduate Theses and Dissertations, Fall 2023 to Present

Synthetic aperture radar (SAR) is the technology that enables the creation of images using radar waves, allowing images to be formed regardless of weather. In bistatic SAR a radar platform uses a radar pulse from a separate platform to form an image. It is important that these radar systems are able to communicate with each other. Rather than wasting energy and space flying with a separate communication system, the radar systems could use the already existing SAR system to send data between each other while still forming SAR images. The work of this thesis is to show how very simple …

Fibrous Protein Biomaterials: Characterization Of Solitary Bee Silk And Cocoons, And Development Of Recombinant Hagfish And Bee Silk Materials, Oran Wasserman

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation explores two complementary aspects of fibrous protein biomaterials: the characterization of understudied naturally occurring solitary bee silk and cocoons; and recombinant expression and biomaterial formation of recombinant hagfish intermediate filaments (rHIF) and a single Osmia lignaria Say (Hymenoptera: Megachilidae) silk protein. Some solitary bee species, which make up about 75% of all bee species, spin silk to construct protective cocoons during development. Despite the importance of silk and cocoons to the solitary bees' life history, their properties remain largely unexplored. This dissertation presents a novel method for isolating and testing individual silk fibers without interfering with the development …

Bridging Animal Production And Human Nutrition: How Production Ecology Shapes The Nutritional Quality Of Terrestrial Animal Foods And Human Omega-3 Status, Joseph Vinod Varre

All Graduate Theses and Dissertations, Fall 2023 to Present

The question at the center of this dissertation is simple: does the way food is produced change the quality of the food itself in ways that matter for human health? Across a series of studies on bison meat, eggs, and human dietary intervention, the answer was yes. This work began with a broad look at the modern food system and the nutritional consequences of industrialized diets. In particular, it focused on the growing imbalance between omega-6 and omega-3 fatty acids in the Western diet. This balance matters because omega-3 fats support heart, brain, and immune health, and diets high in …

Multispecies Weed Detection Using Unmanned Aerial Vehicles And Deep Learning Object Detection Models In Utah Forage Crop Corn Field, Utsav Bhandari

All Graduate Theses and Dissertations, Fall 2023 to Present

Weeds cost global agriculture over $32 billion annually and reduce crop yields by nearly one-third. Current weed control relies heavily on spraying herbicides uniformly across entire fields, leading to herbicide-resistant weeds, environmental harm, and increasing costs for farmers. A smarter approach is detecting weeds from the air and spraying only where they are present. This could dramatically reduce herbicide use while protecting crop yields. This thesis developed a complete system for identifying weeds in corn fields using drone-captured images and artificial intelligence. Working in commercial forage corn fields in Cache Valley, Utah, high-resolution aerial images were collected and used to …

Unifying And Expanding Global And Local Variable Importance Methods For Explainable Machine Learning, Kelvyn K. Bladen

All Graduate Theses and Dissertations, Fall 2023 to Present

Machine learning methods are powerful analytical tools used across all scientific disciplines and many other fields of investigation for prediction and inference from diverse data sources. Despite their broad applicability, machine learning methods are often highly complex and difficult to interpret. Developing a greater understanding of which variables most influence a response is essential for increasing the interpretability of these models and supporting informed decision-making. This research focuses on improving how we evaluate the importance of these variables.

One common approach is to shuffle the values of a variable and see how much the model accuracy gets worse. Another approach …

Reciprocal Teaching With Emergent Bilingual Students: Promoting Academic Reading Strategies And Fostering Hope, Lorissa K. Nelson

All Graduate Theses and Dissertations, Fall 2023 to Present

Many students struggle with reading comprehension, and research shows that low literacy skills in a student’s first language can unfortunately lead to lower rates of university program completion, regardless of the language of instruction. When students feel empowered and confident in their ability to achieve their academic goals, they are much more likely to take ownership of their learning. In fact, students who actively demonstrate hopeful thinking and behaviors are consistently more successful in their academic journeys.

My research explores how we can better support these high school students— specifically concurrent enrollment (CE) students—by examining the impact of Reciprocal Teaching. …

Three Essays In Discrete Choice Analysis: Valuation, Attention Level, And Spatial Heterogeneity, Marcelo Pignatari

All Graduate Theses and Dissertations, Fall 2023 to Present

Understanding how people value food labels and environmental goods is essential for designing policies, incentives, and market mechanisms that improve the well-being of the population. In this study, we found that a local label indicating that fruit was produced in Utah makes Utahns value strawberries, gala apples, and dried tart cherries more. An organic label has a similar effect, which is especially strong for dried tart cherries. In contrast, a freshness label only increases value for fruits with a shorter shelf life, such as strawberries. We also found that people who chose to access clarifying information about what these labels …

Visualizing The Phase Space Of Two Interacting Spherical Magnets Via Lagrangian Descriptors, Matthew Pontius

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis studies the motion of one spherical magnet sliding on another fixed spherical magnet. Although the setup is simple, the resulting motion can range from regular and predictable to chaotic as the energy increases. To understand this behavior, mathematical tools are used to visualize how all possible motions are organized in phase space. These methods reveal patterns such as stable regions, repeating motions, and chaotic trajectories. The results show how order and chaos coexist in this system and provide insight into how small changes in the initial conditions can lead to very different outcomes.

Comparing Error Correction Strategies In Discrete Trial Training For Children With Autism, Rachael Litchford

All Graduate Theses and Dissertations, Fall 2023 to Present

Children diagnosed with Autism Spectrum Disorder (ASD) often require structured, evidence-based teaching methods to promote skill acquisition. Discrete Trial Training (DTT) is one such approach widely used in Applied Behavior Analysis (ABA) to teach skills through repeated learning opportunities. However, limited research has compared the efficiency of specific error correction procedures within DTT. This study examined the comparative effectiveness of two error correction strategies, Active Student Response (ASR) and Model-Only, when acquiring tacting skills for children ages 2-10 with ASD. An alternating treatments design (ATD) was used to evaluate each strategy’s impact on skill acquisition, as measured by the percentage …

Using A Prerequisite Skills Assessment To Identify Effective Communication Modalities For Mand Training, Christine White

All Graduate Theses and Dissertations, Fall 2023 to Present

Many children with Autism Spectrum Disorder (ASD) need support to learn how to communicate their wants and needs. This study examined three different ways to teach children to request preferred items or activities: using sign language, exchanging pictures, and speaking. We compared how three children learned each communication method to determine whether their existing skills influenced which method was most effective. No clear relationship was found between children's existing abilities and how well they learned each communication method. These findings suggest that selecting the most effective communication approach may require considering each child's individual strengths and learning history rather than …

Integrating Space Use And Demography To Support Management Of An Endangered Alpine Ungulate, Danielle J. Berger

All Graduate Theses and Dissertations, Fall 2023 to Present

The places animals choose to live affect the food they find, the dangers they face, and the weather conditions they experience. These experiences influence whether individual animals survive and reproduce, which in turn affects the size and health of animal populations. Although scientists have long believed that animal movements play an important role in population trends, there has been limited real-world evidence showing this connection. Advances in GPS tracking technology now allow researchers to follow animals over long periods and better understand how movement influences survival. Using 20 years of GPS tracking data from the endangered Sierra Nevada bighorn sheep …

The Influence Of Shape Complexity And Exploratory Behavior On Grasping, Mckenzie Gunter

Dissertations

People can orient and configure their hands in many ways in order to grasp objects. The current study investigates how object shape and hand placement influence graspability of objects, and how experimentally imposed constraints on grasping type alter grasping behavior. In a recent study, Gunter and Hajnal (under review) found that the ratio of object curvature and maximal handspan is the variable that defines the affordance of graspability. The current study aims to extend these findings by employing a more precise measurement of finger placement in two experiments using 3D printed objects as stimuli. To capture varying complexities of object …

Vulnerability In The Dark Triad: Insecure Attachment And Relational Aggression In The Peer Relationships Of College Students, Summer Boggs

Dissertations

Research on relational aggression (i.e., a type of aggression in which the aggressor harms others by damaging their relationships, reputation, and/or feelings of social acceptance) with college students has identified several important correlates, including anxious and avoidant attachment styles. Moreover, the personality traits captured by the Vulnerable Dark Triad (VDT; i.e., borderline, the antisocial component of psychopathy, and vulnerable narcissism; Miller et al., 2010) have demonstrated positive relationships with both relational aggression and insecure attachment. This study examined the relationship between insecure attachment and relational aggression among college students (N = 560), testing VDT traits as partial mediators of …

Implementation Of Phq-9 To Improve Depression Identification In Icu, Jenny C. Manoly Bsn, Rn

Doctor of Nursing Practice Final Project Abstract

PURPOSE This quality improvement project aimed to improve depression identification by screening 80% of eligible adults admitted to two heart failure intensive care units (ICU) using the Patient Health Questionnaire-9 (PHQ-9).

RESULTS Screening compliance increased from 42.1% to 85% by Week 13, exceeding the project goal. Of 101 patients screened, 16.8% screened positive for depression. Workflow changes, leadership support, and peer engagement improved compliance, though psychiatric referrals remained inconsistent.

BACKGROUND Depression is common among critically ill patients but is frequently underrecognized because ICU care primarily focuses on physiologic stabilization. Existing admission screening was limited to suicide risk assessment, delaying identification …

A Comparison Of The Effectiveness Of Teacher-Led And Student-Supported Variations Of The Good Behavior Game, Patrick Wells

All Graduate Theses and Dissertations, Fall 2023 to Present

This project examined the effectiveness of two variations of the Good Behavior Game (GBG) intervention: the traditional teacher-led and a student-supported variation. The traditional intervention has been shown to be an effective intervention for reducing disruptive classroom behaviors. Despite its effectiveness, proper implementation does require additional effort from the teacher—effort that may better be directed toward improving instruction. A student-supported variation of the intervention has the potential to reduce the effort required of teachers who wish to implement the intervention in their classroom. We utilized a nonconcurrent, multiple baseline design with alternating treatment to compare the effectiveness of both versions …

Effects Of Single-Session Interventions On Youth Internalizing Problems, Thomas K. Franzmann

All Graduate Theses and Dissertations, Fall 2023 to Present

Anxiety and depression are among the most common mental health concerns young people face, and they often interfere with school, friendships, family life, and long-term well-being. Even though effective therapies exist, only about half of youth who need care ever receive it, and among those who do start treatment, the most common total number of sessions a young person attends is one. This gap between what young people need and what they actually receive raises a practical question for the field: can a single, well-designed meeting with a provider produce meaningful change for some youth and families, and what should …

Carbon Cycling, Salinization, And Long-Term Water Quality Trends In Rocky Mountain Streams, Allyson J. Marrs

All Graduate Theses and Dissertations, Fall 2023 to Present

Humans have greatly affected streams and rivers worldwide through urbanization, agriculture, and water use. The purpose of my dissertation is to increase our understanding of various human impacts on rivers. In chapter two, I aim to determine whether there are differences in greenhouse gas (GHG) emissions between a natural river and manmade canals. I did this by measuring the emissions and dissolved concentrations of three of the most prevalent GHGs, carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). I found that most of the sites I studied were emitting CO₂ and CH …

Visibility Assessment In Urban Areas: Exploring Measures And Approaches For Viewing Green Space, Doo Hong Lee

All Graduate Theses and Dissertations, Fall 2023 to Present

Urban greenery is often used to understand the quality of living conditions in cities. However, measuring greenery is not always simple. Some methods show how much vegetation exists from above, while others try to show what people actually see while walking or moving through streets. These are different ways of understanding green space. This dissertation focuses on visible greenness, or the greenery that people can see from eye level in everyday urban environments.

This research addresses a practical problem. Many existing methods for measuring visible greenness require large image datasets, advanced computing, or commercial street-view images. These requirements can make …

Impact Of Chronic Stress And Nutrition On Functional Connectivity And Neural Networks In Young Kichwa Children From The Ecuadorian Amazon Rainforest, Matthew L. Cook

All Graduate Theses and Dissertations, Fall 2023 to Present

Early childhood is a critical period for brain development. Positive and negative experiences during this time can have lasting effects on learning, health, and well-being. However, most research on children’s brain development has been conducted in wealthy, industrialized nations, leaving important gaps in our understanding of how children develop in other cultural and environmental contexts.

This study examined brain development in Indigenous Kichwa children living in two rural communities in the Ecuadorian Amazon Rainforest. The goal was to better understand how chronic stress and nutrition may influence a child’s developing brain during early childhood. Children participated in noninvasive brain assessments …