Theses and Dissertations from UMD
Permanent URI for this communityhttp://hdl.handle.net/1903/2
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 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 DATA-DRIVEN ANALYSIS OF INDIVIDUAL THERMAL COMFORT WITH PERSONALIZED COOLING(2018) Dalgo, Daniel Alejandro; Srebric, Jelena; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation presents numerical and experimental results on the effects of Personal Cooling Devices (PCDs) on the energy consumption of buildings and the thermal comfort of occupants. The objective of this analysis was to quantify the tradeoffs of thermal comfort and energy savings associated with PCD technology. Furthermore, this investigation included an electrical cost analysis associated with PCDs at the building level for different cities across the United States. The results of energy and cost analyses, at the building level, indicated the potential for cooling energy and cost savings associated with shifting the electricity consumption during the peak hours to the off-peak hours of the day. The numerical analysis of human thermal comfort demonstrated the potential for PCDs to regulate human thermal comfort at warm environmental conditions. The thermal comfort level achieved in the numerical simulations were within the limits recommended by ASHRAE Standard 55. In addition, the numerical simulations permitted the evaluation of PCD performance based on thermal comfort, and the amount of sensible heat remove from the human body. The experimental work evaluated the performance of PCDs using both subjective and objective measurements of thermal comfort for 14 human subjects. The results demonstrated the ability of a PCD to change and maintain acceptable thermal comfort micro-environments for human subjects under warm conditions. Furthermore, the results showed that a PCD had measurable effects on physiological variables that control the thermoregulatory process of the human body. Specifically, variables such as skin temperature and heart rate variability in the time and frequency domain responded to the micro-environment created by the PCD. This research established a relationship between skin temperature, heart rate variability, and thermal comfort. Overall, this investigation performed a comprehensive analysis of the interaction of PCDs with: building energy consumption, human subjects, and human physiological processes; and demonstrated the potential to recognize human subjects’ thermal comfort based on physiological signals.Item The Effects of Mood and Stress on Cardiovascular Responses(2011) Sadak, Christina Elisa; Smith, Barry D; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The "reactivity hypothesis" posits that elevations in cardiovascular reactivity may increase the risk of developing adverse cardiovascular events over time. Negative emotions and stress may exacerbate cardiovascular reactivity, as represented by increases in blood pressure and heart rate responses. However, prior studies have reported mixed results. Therefore the primary goal of the present study was to examine the effects of stimuli intended to elicit either sadness (negative mood induction) or mental stress (stressor tasks) on blood pressure and heart rate responses, in particular, when placed alongside each other in one experimental paradigm. One hundred and six participants were randomized to one of four conditions: Mood Induction (Sad or Neutral) Only or Mood Induction (Sad or Neutral) plus Stressor Tasks. Continuous measures of heart rate and blood pressure were collected, in addition to periodic self-report measurements of sadness and perceived stress. It was first hypothesized that participants in the Mood Induction plus Stressor Task conditions would exhibit greater blood pressure and heart rate responses than the participants in the Mood Induction Only conditions. It was also hypothesized that the elicitation of a negative emotion would not predict significant increases in blood pressure and heart rate. Third, it was hypothesized that the elicitation of a negative emotion would not affect the relationship between the stressor tasks and blood pressure and heart rate. Finally, it was hypothesized that males would exhibit greater blood pressure responses than female participants. Data were analyzed using reactivity scores in a series of statistical analyses. Results supported several of the hypotheses, confirming that certain stressor tasks significantly increase blood pressure and heart rate responses. Findings also provided evidence that a negative mood induction is associated with significant increases in blood pressure and heart rate responses, even though these responses may not be unique to this specific negative emotion. Implications for future work, including clinical applications, are discussed.