Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
Displaying 81 - 86 of 86
Description
Detection of extruded features like rooftops and trees in aerial images automatically is a very active area of research. Elevated features identified from aerial imagery have potential applications in urban planning, identifying cover in military training or flight training. Detection of such features using commonly available geospatial data like orthographic aerial imagery is very challenging because rooftop and tree textures are often camouflaged by similar looking features like roads, ground and grass. So, additonal data such as LIDAR, multispectral imagery and multiple viewpoints are exploited for more accurate detection. However, such data is often not available, or may be improperly registered or inacurate. In this thesis, we discuss a novel framework that only uses orthographic images for detection and modeling of rooftops. A segmentation scheme that initializes by assigning either foreground (rooftop) or background labels to certain pixels in the image based on shadows is proposed. Then it employs grabcut to assign one of those two labels to the rest of the pixels based on initial labeling. Parametric model fitting is performed on the segmented results in order to create a 3D scene and to facilitate roof-shape and height estimation. The framework can also benefit from additional geospatial data such as streetmaps and LIDAR, if available.
ContributorsKhanna, Kunal (Author) / Femiani, John (Thesis advisor) / Wonka, Peter (Thesis advisor) / Razdan, Anshuman (Committee member) / Maciejewski, Ross (Committee member) / Arizona State University (Publisher)
Created2013
Description
Critical infrastructures in healthcare, power systems, and web services, incorporate cyber-physical systems (CPSes), where the software controlled computing systems interact with the physical environment through actuation and monitoring. Ensuring software safety in CPSes, to avoid hazards to property and human life as a result of un-controlled interactions, is essential and challenging. The principal hurdle in this regard is the characterization of the context driven interactions between software and the physical environment (cyber-physical interactions), which introduce multi-dimensional dynamics in space and time, complex non-linearities, and non-trivial aggregation of interaction in case of networked operations. Traditionally, CPS software is tested for safety either through experimental trials, which can be expensive, incomprehensive, and hazardous, or through static analysis of code, which ignore the cyber-physical interactions. This thesis considers model based engineering, a paradigm widely used in different disciplines of engineering, for safety verification of CPS software and contributes to three fundamental phases: a) modeling, building abstractions or models that characterize cyberphysical interactions in a mathematical framework, b) analysis, reasoning about safety based on properties of the model, and c) synthesis, implementing models on standard testbeds for performing preliminary experimental trials. In this regard, CPS modeling techniques are proposed that can accurately capture the context driven spatio-temporal aggregate cyber-physical interactions. Different levels of abstractions are considered, which result in high level architectural models, or more detailed formal behavioral models of CPSes. The outcomes include, a well defined architectural specification framework called CPS-DAS and a novel spatio-temporal formal model called Spatio-Temporal Hybrid Automata (STHA) for CPSes. Model analysis techniques are proposed for the CPS models, which can simulate the effects of dynamic context changes on non-linear spatio-temporal cyberphysical interactions, and characterize aggregate effects. The outcomes include tractable algorithms for simulation analysis and for theoretically proving safety properties of CPS software. Lastly a software synthesis technique is proposed that can automatically convert high level architectural models of CPSes in the healthcare domain into implementations in high level programming languages. The outcome is a tool called Health-Dev that can synthesize software implementations of CPS models in healthcare for experimental verification of safety properties.
ContributorsBanerjee, Ayan (Author) / Gupta, Sandeep K.S. (Thesis advisor) / Poovendran, Radha (Committee member) / Fainekos, Georgios (Committee member) / Maciejewski, Ross (Committee member) / Arizona State University (Publisher)
Created2012
Description
Over the past several decades, middle-aged Americans have exhibited troubling trends of declining mental and physical health over successive cohorts. Interestingly, this trend has not been observed in peer nations in Europe, Asia, and Mexico. Later-born cohorts in other countries typically report better midlife mental and physical health than their earlier-born counterparts. It is less clear the extent to which physical pain shows similar trends to what has been observed in the U.S. and comparison peer nations. The goal of the current study was to examine how self-reports of pain have historically changed during midlife and investigate whether differences emerge between the U.S. and peer nations. We used harmonized data on pain from nationally representative longitudinal panel surveys from the U.S., 13 European nations, South Korea, and Mexico to directly quantify similarities and differences in historical change in midlife pain. Our results supported the hypothesis that midlife pain is higher amongst later-born cohorts in the U.S. A similar pattern of historical increases in pain was observed in Continental and Nordic Europe. In England, Mediterranean Europe, South Korea, and Mexico, the opposite pattern was observed with historical declines in pain. Historical increases in reports of pain in the U.S. emerged more quickly for later-born cohorts at earlier stages of midlife. These results suggest there could be aspects of American midlife today that are exacerbating reports of pain, and these aspects may be shared in some European nations but absent or less influential in other peer nations. Our discussion focuses on potential explanations for this pattern, such as population level discrepancies in health, differential use of health care services, and the inter/intrapersonal costs of westernization, as well as how pain is conceptualized across nations.
ContributorsSyed, Orchee (Author) / Infurna, Frank (Thesis director) / Corbin, William (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor)
Created2023-12
Description
Previous evidence implicating fighting gameplay with markers for cardiovascular changes in response to stress appraisals emphasizes the plausibility of additional biopsychosocial factors varying between players and dictating gameplay changes (Porter & Goolkasian, 2019). The current study builds upon previous research using the Biopsychosocial Model of Challenge and Threat (Blascovich and Tomaka, 1996) alongside the Mental Load Rating Scale (Hughes, 2023) to link perceptions of increased stress during gameplay with increases in gameplay errors. Participants were allotted a set time to acclimate to fighting game mechanics, then began combo trials. The game used in research (Street Fighter 6) requires precise movements in rapid succession completion the completion of a “combo”. Competitive fighting game players were compared to players lacking fighting game experience in post-participation response measuring stress salience or hindrance perception, as well as total input error comparison. Current findings suggest Competitive fighting game players report factors such as spectator viewing and time limits as hindrances capable of being overcome as opposed to Noncompetitor reports of factors and stressors during game acclimation. Findings between Competitor and Noncompetitor groups allude to cultural significance when navigating gameplay. Future research should continue measuring sociocultural perception of stress when navigating specific genres of video game play and avenues for stress reappraisal techniques.
ContributorsDavis, Nicholas (Author) / Holloway, Steven (Thesis director) / Flores, Valerie (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2023-12
Description
Approximately 20% of youth experience mental health problems (Vasileva et al., 2021), and dimensions of early childhood temperament, specifically negative affectivity and effortful control, predict later mental health (Rothbart, 2007). Examining temperament using person-centered methods, particularly in stressful contexts, may improve our understanding of vulnerability to adolescent emotional problems. The current study examined whether specific patterns, or types, of infant temperament longitudinally predicted adolescent anxiety and depression symptoms and whether family relationship stress moderated this association. We hypothesized that infants with a Negative Dysregulated temperament would experience higher anxiety and depression symptoms in later childhood compared to those with a Typical Expressive temperament, and that family relationship stress would exacerbate this link. In an ongoing-longitudinal study of families with twins (N=563, 51% female, 29.8% Hispanic/Latinx, 58.4% White; Lemery-Chalfant et al., 2019), primary caregivers (PCs) reported on infant temperament at 12 months (IBQ; Gartstein & Rothbart, 2003, α=.74-.90). In a prior study (Murillo et al., 2023), latent profile analysis yielded three infant temperament types: Negative Dysregulated, Positive Well-Regulated, and Typical Expressive. PCs reported on partner strain (PSS; Schuster, Kessler, & Asseltine, 1990, α=.87) and family conflict (FCS; Porter & O’Leary, 1980, α=.80) at age 8 and a composite of these two measures represented Family Relationship Stress (r = .689). Confirmatory factor analysis was used to form Depression and Anxiety outcome composites based on PC (4 reports), secondary caregiver (2 reports), teacher (2 reports), and self-report (3 reports) measures of depression and anxiety symptoms collected from ages 8-11 (HBQ, Armstrong & Goldstein, 2003; BPI, Measelle et al., 1998, all α’s > .80). We randomly selected one twin from each pair and conducted regression analyses, and then used the second twin for an internal replication. Family relationship stress had a significant main effect on both anxiety and depressive symptoms. The Negative Dysregulated temperament type did not predict anxiety and depression at ages 8-11, however, it interacted with family relationship stress to predict anxiety and depression in 1 of 2 samples. When family relationship stress was low, the Negative Dysregulated type was significantly associated with higher anxiety and depression outcomes compared to the Typical Expressive type, and high family relationship stress was significantly associated with lower depression outcomes. Elucidating these longitudinal relations is important for informing early intervention and reducing the burden of adolescent psychopathology.
ContributorsSingh, Ajuni (Author) / Lemery-Chalfant, Kathryn (Thesis director) / Corbin, William (Committee member) / Davis, Mary (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor) / Sanford School of Social and Family Dynamics (Contributor)
Created2023-12
Description
Research on self-regulatory variables like mindfulness and effortful control proposes strong links with physical and mental health outcomes across the lifespan, from childhood and adolescence to adulthood and old age. One pathway by which self-regulation may confer health benefits is through individual differences in reports of and emotional responses to daily negative and positive events. Mindfulness is broadly defined as non-reactivity to inner experiences, while effortful control is broadly defined as attentional and behavioral regulation. Mindfulness and effortful control have both been conceptualized to exert their beneficial effects on development through their influence on exposure/engagement and emotional reactivity/responsiveness to both negative and positive events, yet few empirical studies have tested this claim using daily-diary designs, a research methodology that permits for examining this process. With a sample of community-dwelling adults (n=191), this thesis examined whether dispositional mindfulness (i.e., non-reactivity of inner experience) and effortful control (i.e., attention and behavioral regulation) modulate reports of and affective reactivity/responsiveness to daily negative and positive events across 30 days. Results showed that mindfulness and effortful control were each associated with reduced exposure to daily stressors but not positive events. They also showed that mindfulness and effortful control, respectively, predicted smaller decreases in negative affect and smaller increases in positive affect on days that positive events occurred. Overall, these findings offer insight into how these self-regulatory factors operate in the context of middle-aged adults’ everyday life.
ContributorsCastro, Saul (Author) / Infurna, Frank (Thesis advisor) / Doane, Leah (Committee member) / Davis, Mary (Committee member) / Arizona State University (Publisher)
Created2018