Theses and Dissertations from UMD
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New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a give thesis/dissertation in DRUM
More information is available at Theses and Dissertations at University of Maryland Libraries.
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Item Computational Methods for Natural Walking in Virtual Reality(2024) Williams, Niall; Manocha, Dinesh; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Virtual reality (VR) allow users to feel as though they are really present in a computer-generated virtual environment (VE). A key component of an immersive virtual experience is the ability to interact with the VE, which includes the ability to explore the virtual environment. Exploration of VEs is usually not straightforward since the virtual environment is usually shaped differently than the user's physical environment. This can cause users to walk on virtual routes that correspond to physical routes that are obstructed by unseen physical objects or boundaries of the tracked physical space. In this dissertation, we develop new algorithms to understand how and enable people to explore large VEs using natural walking while incurring fewer collisions physical objects in their surroundings. Our methods leverage concepts of alignment between the physical and virtual spaces, robot motion planning, and statistical models of human visual perception. Through a series of user studies and simulations, we show that our algorithms enable users to explore large VEs with fewer collisions, allow us to predict the navigability of a pair of environments without collecting any locomotion data, and deepen our understanding of how human perception functions during locomotion in VR.Item VIRTUAL RISK: PERCEIVED PSYCHOLOGICAL DISTANCE OF THREAT IN IMMERSIVE VIRTUAL ENVIRONMENTS(2024) Leach, John; Namkoong, Kang; Communication; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Wildfires pose a significant and growing threat to human health and the environment, exacerbated by climate change. This study explores how to communicate the urgency of wildfires and climate change using Construal Level Theory (CLT) and immersive virtual environments (IVEs). CLT explains how people psychologically distance themselves from events, perceiving them as either abstract or concrete. Typically, environmental issues like wildfires are construed as distant and abstract, reducing the likelihood of proactive behavior.A promising strategy to counter this is "proximizing," or making threats seem more immediate, thereby reducing psychological distance. However, past research on proximizing environmental messages has yielded mixed results. Immersive media, particularly virtual reality (VR), offers a unique opportunity to create vivid simulations that feel like direct experiences, potentially overcoming psychological distance. Through a two-part experiment, this dissertation investigates how IVEs can be used to enhance the relationship between psychological distance, threat perceptions, and pro-environmental behavior by simulating wildfires and testing various narrative framings. Study I tested the effects of immersive format and social distance framing on threat perception and behavioral intention. Results indicated that VR heightened the sense of presence and perceived threat, aligning with previous research on VR's impact on environmental communication. However, the social distance manipulation did not significantly affect perceived threat or behavior, suggesting the immersive quality of VR might overshadow social distance effects. Study II focused on social and spatial distance construal, finding that closer spatial framing increased perceived threat, supporting the idea that spatial proximity is more immediately relatable and impactful. These findings suggest that while IVEs can effectively enhance threat perception, manipulating social and spatial distance requires careful consideration. The sense of presence in IVEs plays a crucial role, mediating the relationship between immersive format and perceived threat. This research contributes to communication theory by exploring the nuanced interplay between psychological distance, presence, and immersive experiences. Practically, it offers insights into designing effective environmental messages to reduce psychological distance and promote pro-environmental behavior. Future research should further investigate the complex dynamics of psychological distance and presence in immersive environments to optimize VR's use in environmental communication.Item Studying the Effects of Colors Within Virtual Reality (VR) on Psychological and Physical Behavior(2024) Fabian, Ciara Aliese; Aston, Jason; Library & Information Services; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Color theory is an important aspect of today's world, especially when consideringuser design, technology, and art. The primary objective of this thesis is to examine how the color groups, warm and cool, affect individuals psychologically and physiologically. While combining technological advancements, physiological methods, and psychological analyses, I will try to discover the emotional associations with specific color groups and determine the psychological and physiological impact of color groups on individuals. I hypothesize that warm colors will increase heart rate and skin conductance response, which will directly correlate to emotions of stress and excitement, and cool colors will decrease heart rate and skin conductance, which is associated with the emotions of calmness and positivity. This study demonstrated that the two-color groups exhibited a notable influence on heart rate. Using the skin conductance response method yielded unanticipated results in comparison to prior research. Prior studies have shown that there is a relationship between heart rate and skin conductance response, and therefore, if one increases, then the other should also increase. This study found that when the heart rate increased, many participants experienced a decrease in skin conductance response, showcasing a contrast in physiological reaction. Furthermore, the study demonstrated a correlation between physiological changes, such as heart rate variations, and corresponding changes in participants' psychological behavior.Item LUCID DREAMS: AN EXPLORATION IN IMMERSIVE INTERACTIVE STORYTELLING WITH AUGMENTED REALITY(2024) Lazar, Rashonda; Kachman, Misha; Theatre; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The following thesis examines my design process and discoveries while investigating one way live performance and immersive storytelling can act as a form of augmented reality, and explores whether incorporating traditional forms of augmented reality is one way to enhance a performance and builds on the narrative agency audiences experience in immersive theater. The production opened on April 8th, 2024, in the Herman Maril Gallery at the Parren J. Mitchell Art and Sociology Building at the University of Maryland.Item Immersive Visual Analytics of Wi-Fi Signal Propagation and Network Health(2023) Rowden, Alexander R; Varsnhney, Amitabh; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)e are immersed in waves of information. This information is typically transmitted as radio waves in many protocols and frequencies, such as WiFi, Bluetooth, and Near-Field Communications (NFC). It carries vital information such as health data, private messages, and financial records. There is a critical need for systematic and comprehensive visualization techniques to facilitate seamless, resilient, and secure transmission of these signals. Traditional visualization techniques are not enough because of the scale of these datasets. In this dissertation, we present three novel contributions that leverage advances in volume rendering and virtual reality (VR): (a) an outdoor volume-rendering visualization system that facilitates large-scale visualization of radio waves over a college campus through real-time programmable customization for analysis purposes, (b) an indoor, building-scale visualization system that enables data to be collected and analyzed without occluding the user's view of the environment, and (c) a systematic user study with 32 participants which shows that users perform analysis tasks well with our novel visualizations. In our outdoor system, we present the Programmable Transfer Function. Programmable Transfer Functions offer the user a way to replace the traditional transfer function paradigm with a more flexible and less memory-demanding alternative. Our work on indoor WiFi visualization is called WaveRider. WaveRider is our contribution to indoor-modeled WiFi visualization using a virtual environment. WaveRider was designed with the help of expert signal engineers we interviewed to determine the needs of the visualization and who we used to evaluate the application. These works provide a solid starting point for signal visualization as our networks transition to more complex models. Indoor and outdoor visualizations are not the only dichotomy in the realm of signal visualization. We are also interested in visualizations of modeled data compared to visualization of data samples. We have also explored designs for multiple sample-based visualizations and conducted a formal evaluation where we compare these to our previous model-based approach. This analysis has shown that visualizing the data without modeling improves user confidence in their analyses. In the future, we hope to explore how these sample-based methods allow more routers to be visualized at once.Item Real-time Audio Reverberation for Virtual Room Acoustics(2020) Shen, Justin M; Duraiswami, Ramani; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)For virtual and augmented reality applications, it is desirable to render audio sources in the space the user is in, in real-time without sacrificing the perceptual quality of the sound. One aspect of the rendering that is perceptually important for a listener is the late-reverberation, or "echo", of the sound within a room environment. A popular method of generating a plausible late reverberation in real-time is the use of Feedback Delay Network (FDN). However, its use has the drawback that it first has to be tuned (usually manually) for a particular room before the late-reverberation generated becomes perceptually accurate. In this thesis, we propose a data-driven approach to automatically generate a pre-tuned FDN for any given room described by a set of room parameters. When combined with existing method for rendering the direct path and early reflections of a sound source, we demonstrate the feasibility of being able to render audio source in real-time for interactive applications.Item THE INFLUENCE OF WATERPIPE LOUNGE MENU LABELING ON INTENTION TO QUIT SMOKING AND PERCEIVED HARM, RISK AND ADDICTION AMONG YOUNG ADULT WATERPIPE TOBACCO SMOKERS IN THE UNITED STATES(2020) Kidanu, Azieb; Feldman, Robert H; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In the US, young adults 18 to 24 years of age have experienced the most notable decline in smoking rates from 24.4% in 2005 (Mariolis et al., 2006) to 7.8% in 2018 (Creamer, 2019). However, alternative tobacco products, such as waterpipes (also known as hookahs), are increasingly becoming the first product used by tobacco-naïve young adults and may be a gateway to nicotine addiction (Meier, Tackett, Miller, Grant, & Wagener, 2015). Tobacco surveillance measures show that among young adults in the US, 44.3% reported ever use (lifetime) and 10.7% current use (every day and someday) of waterpipe tobacco (Kasza et al., 2017). Although public health best practices for communicating the harms of tobacco use are well-established in traditional products, such as cigarettes, there is a critical knowledge gap on how to properly communicate the harms of waterpipe tobacco smoking (WTS) to current and potential consumers. In this dissertation, two independent studies were conducted to examine the effect of health-related information on waterpipe lounge menus on intention to quit smoking, as well as perceived relative harm, perceived risk of health consequences and perceived relative addiction.The overall results of Study 1 and Study 2 were consistent with prior research showing that brief health warning messages and nicotine content may increase intention to quit smoking, as well as perceived harm and risk of health consequences (Mays, Tercyak, et al., 2016). In addition, the research expands this evidence by demonstrating that the waterpipe lounge menu is a viable location for delivery of health education messages and product labeling. These findings may be used in future research to design further health communication experiments for WTS, as well as support practice and policy decisions for health warning messages and product labeling specific to waterpipe tobacco.Item SIMULATING REALITY: TRAINING CITIZEN SCIENTISTS TO JUDGE STREAM HABITATS IN MULTISENSORY VIRTUAL REALITY(2019) Striner, Alina Goldman; Preece, Jennifer; Library & Information Services; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Citizen science is a form of crowdsourcing that allows volunteers to participate in scientific data collection and analysis. Many citizen scientists are engaged and motivated by science-based learning and discovery, but high training costs and limited resources often result in volunteers participating in unskilled work, leading to boredom and disengagement. Advances in immersive virtual reality (VR) have created opportunities to recreate physical environments with minimal cost, making it possible to train citizen scientists to make qualitative experiential judgments usually reserved for domain experts. This research trains citizen scientists to assess outdoor stream habitats using StreamBED VR, a multisensory VR training platform. This research offers the following contributions: 1. A study of how expert and novice water monitors make qualitative assessments of outdoor stream habitats using an EPA qualitative protocol. The research found that experts develop intuitive judgments of quality, use multisensory environmental information to make judgments, and construct past and future narratives of streams using environmental characteristics. 2. Iterative design of the Ambient Holodeck multisensory system, and a study of how ambient sensory information impacts observation skills. The research found that multisensory information increased the number of observations participants made, and positively affected engagement and immersion. 3. Iterative design of the StreamBED VR training platform, and two studies; the former explores how qualitative assessment skills can be taught in VR, and the latter considers how training in VR, with and without Multisensory cues, compares to a PowerPoint (PPT) baseline. Study results found although VR participants were more excited to continue training than PPT participants, Standard VR and PPT participants scored closest to an expert gold standard, performing significantly better than Multisensory VR participants. This research concludes that VR has the potential to train qualitative assessment tasks, but qualifies that training design is multifaceted and complex, full of theoretical learning considerations and practical challenges. Further, VR realism can be a powerful tool for training, but is only effective when training cues clearly parallel assessment tasks.Item Towards Visual Analytics in Virtual Environments(2018) Krokos, Eric; Varshney, Amitabh; Computer Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Virtual reality (VR) is poised to become the new medium through which we engage, view, and consume content. In contrast to traditional 2D desktop displays, which restrict our interaction space onto an arbitrary 2D-plane with unnatural interaction mechanisms, VR expands the visualization and interaction space into our 3D domain, enabling natural observations and interactions with information. With the rise of Big Data, processing and visualizing such enormous datasets is of utmost importance and remains a difficult challenge. Machine learning, specifically deep learning, is rising to meet this challenge. In this work, we present several studies: (a) demonstrating the effectiveness of immersive environments over traditional desktops for memory recall, (b) quantifying cybersickness in virtual environments, (c) enabling human analysts and deep learning to support, refine, and enhance each other through visualization, and (d) visualizing root-DNS information, enabling analysts to find new and interesting anomalies and patterns. In our first work, we conduct a user study where participants memorize and recall a series of spatially-distributed faces on both a desktop and head-mounted display (HMD). We found that the use of virtual memory palaces in the HMD condition improves recall accuracy when compared to the traditional desktop condition. This improvement was statistically significant. Next, we present our work on quantifying cybersickness through EEG analysis. We found statistically significant correlations with increases in delta, theta, and alpha brain waves with self-reported sickness levels, enabling future virtual reality developers to design countermeasures. Third, we present our work on enabling domain experts to discover hidden labels and communities within unlabeled (or coarsely labeled) high-dimensional datasets using deep learning with visualization. Lastly, we present a 3D visualization of root-DNS traffic, revealing characteristics of a DDOS attack and changes in the distribution of queries received over time. Together, this work takes the first steps in bringing together machine learning, visual analytics, and virtual reality.Item USER INTERFACE CHANGES IN VIRTUAL ENVIRONMENTS AFFECT THE PERCEIVED RESPONSES OF INDOOR CYCLISTS(2018) Stone, Rebecca; Golbeck, Jennifer A.; Library & Information Services; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Virtual reality is becoming mainstream in areas such as entertainment, medicine and training. However, the affect on a user’s perceived states are still to be fully understood. This study aims to add to the existing body of research by examining changes in user interfaces and the affect on perceived responses. Subjects in the study were exposed to two virtual environments, while undertaking a physical exercise task. Their perceived responses were captured through a combination of interviews, observations, and surveys. This differs from previous studies in that it is capturing the perceived differences between the environments themselves. The results highlighted that the content of the environments resulted in a variety of interesting, and unexpected, perceived responses.