Theses and Dissertations from UMD
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Item Preventing Drowsy Driving in Young Adults Through Messaging Strategies that Influence Perceptions of Control and Risk(2024) Lee, Clark Johnson; Butler III, James; Beck, Kenneth H; Public and Community Health; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Drowsy driving is a serious health and safety problem in the United States: thousands of car crashes on U.S. roadways each year are attributed to this risky driving behavior. Although young drivers under the age of 26 years are especially at risk for being involved in drowsy driving car crashes, few anti-drowsy driving interventions targeting such drivers have been developed. Furthermore, most existing educational materials and interventions against drowsy driving have focused primarily on providing factual information about the dangers of drowsy driving and countermeasures against these dangers rather than on influencing beliefs and motivations underlying drowsy driving behavior, which may explain their apparent ineffectiveness at preventing drowsy driving behavior and resultant car crashes. Recent research indicates that messages targeting perceptions of control may be effective intervention strategies against drowsy driving behavior for young adult drivers by influencing their drowsy driving-related perceptions of risk, intentions, and willingness. This dissertation continues this line of research by pursuing two lines of inquiry. In Study #1, the efficacy of anti-drowsy driving messaging strategies designed to influence perceptions of control and risk related to drowsy driving behavior in reducing drowsy driving intentions, willingness, and behavior in a sample of young adult U.S. drivers between 18 and 25 years of age was evaluated through a randomized controlled trial. Study #1 sought to test the following hypotheses: Hypothesis 1: Participants exposed to interventional messaging strategies primarily aimed at lowering perceptions of control or heightening perceptions of risk related to drowsy driving report significantly less perceived control, greater perceived risk, less intentions, less willingness, and less behavior related to drowsy driving at 30-day post-intervention follow-up compared to participants exposed to messaging strategies providing only factual information about the dangers of drowsy driving; and Hypothesis 2: Participants exposed to interventional messaging strategies aimed at both lowering perceptions of control and heightening perceptions of risk related to drowsy driving report significantly less perceived control, greater perceived risk, less intentions, less willingness, and less behavior related to drowsy driving at 30-day post-intervention follow-up compared to participants exposed to messaging strategies providing only factual information about the dangers of drowsy driving, messaging strategies primarily aimed at lowering perceptions of control related to drowsy driving, or messaging strategies primarily aimed at heightening perceptions of risk related to drowsy driving. In Study #2, the relationships between perceived behavioral control, risk perception, intentions, willingness, and drowsy driving behavior in a sample of young adult U.S. drivers between 18 and 25 years of age were examined. Study #2 sought to test the following hypotheses: Hypothesis 3: The impact of interventional messaging strategies targeting drowsy driving perception of control on drowsy driving intentions, willingness, and behavior is mediated by drowsy driving risk perception such that messages lowering drowsy driving perceptions of control also heighten drowsy driving risk perception, which in turn decreases drowsy driving intentions, willingness, and behavior; Hypothesis 4: Interventional messaging strategies targeting drowsy driving-related perceptions of control or risk have a greater impact on drowsy driving willingness than on drowsy driving intentions; and Hypothesis 5: Drowsy driving willingness is a stronger predictor of drowsy driving behavior than is drowsy driving intentions. Study #1 provided supporting evidence of short-term cognitive effects but not short-term behavioral effects after exposure to messaging interventions designed to influence perceptions of control and risk related to drowsy driving behavior. Perceptions of risk were especially influenced by the messaging strategies examined, including those that provided only factual, knowledge-based information about drowsy driving. Study #2 provided supporting evidence that perceived behavioral control influenced drowsy driving intentions and drowsy driving willingness indirectly through perceptions of risk. Furthermore, willingness to drive drowsy was a stronger predictor of actual drowsy driving behavior than intentions to drive drowsy. The findings from these two studies should inform future research aimed at developing more effective messaging strategies against drowsy driving behavior in young adults.Item Perfectionism and eating disorder symptoms: An analysis of the protective effects of ethnic identity in female Latinx college students(2023) Cerrato, Stephanie; O'Neal, Colleen; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Disordered eating in college student populations is highly prevalent. Even so, eating disorder research has largely centered on risk and protective factors relevant to White women, while neglecting to focus on the experiences of people with marginalized identities. The current cross-sectional study a) assessed the relation between evaluative concerns and strivings subscales of perfectionism on disordered eating symptoms in Latinx college women, and b) determined if a high sense of ethnic identity may moderate this relation such that as ethnic identity increases, the effects of perfectionism on disordered eating symptoms decreases. Latinx women from a Mid-Atlantic university (n = 113) completed self-report questionnaires of perfectionism, ethnic identity, and disordered eating. Results revealed that evaluative concerns was a positive predictor of dietary restraint, shape and weight over-evaluation, and body dissatisfaction. Moderation results were non-significant.Item BEYOND RISK: VOLUNTARY DISCLOSURE UNDER AMBIGUITY(2022) Rava, Ariel; Zur, Emanuel; Business and Management: Accounting & Information Assurance; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)In my dissertation, I examine the impact of ambiguity (Knightian uncertainty), alongside that of risk, on firms’ voluntary disclosure decisions. I confirm the well-known result that an increase in risk—uncertainty over outcomes—is associated with an increase in management guidance (earnings and capital expenditure forecasts). Conversely, I find that an increase in ambiguity—uncertainty over the probabilities of outcomes—is associated with less guidance. Furthermore, I show that ambiguity decreases following voluntary disclosures, consistent with managers being aware of and reacting to heightened ambiguity. Finally, I provide novel empirical evidence showing that guidance under ambiguity has adverse capital market consequences. Even though the ways through which risk impacts managers’ disclosure decisions have been extensively studied in the accounting literature, no extant research has examined whether and how ambiguity impacts these decisions. My findings are consistent with the notion that managers’ take into account the ambiguity in the environment, showing that ambiguity has an important and distinct impact on their voluntary disclosure decisions.Item Root Cause Analysis Of Adverse Events Using A Human Reliability Analysis Approach(2022) Johnson, David Michael; Vaughn-Cooke, Monifa; Reliability Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Large scale analysis of adverse event data is challenging due to the unstructured nature of event reporting and narrative textual data in adverse event repositories. This issue is further complicated for human error adverse events, which are routinely treated as a root cause instead of as initiating events in a causal chain. Human error events are commonly misunderstood and underreported, which hinders the analysis of trends and the identification of risk mitigation strategies across industries. Currently, the prevailing means of human error investigation is the analysis of accident and incident data which are not designed around a framework of human cognition or psychomotor function. Existing approaches lack a theoretical foundation with sufficient cognitive granularity to identify root causes of human error. This research provides a cognitive task decomposition to standardize the investigation, reporting, and analysis of human error adverse event data in narrative textual form. The proposed method includes a qualitative structure to answer six questions (when, who, what, where, how, why) that are critical to comprehensively understand the events surrounding human error. This process is accomplished in five main stages: (1) Develop guidelines for a cognitively-driven adverse event investigation; (2) Perform a baseline cognitive task analysis (when) to document relevant stakeholders (who), products or processes (what), and environments (where) based on a taxonomy of cognitive and psychomotor function; (3) Identify deviations for the baseline task analysis in the form of unsafe acts (how) using a human error classification; (4) and Develop a root cause mapping to identify the performance shaping factors (PSFs) (why) for each unsafe act. The outcome of the proposed method will advance the fields of risk analysis and regulatory science by providing a standardized and repeatable process to input and analyze human error in adverse event databases. The method provides a foundation for more effective human error trending and accident analysis at a greater level of cognitive granularity. Application of this method to adverse event risk mitigations can inform prospective strategies such as resource allocation and system design, with the ultimate long-term goal of reducing the human contribution to risk.Item PROPOSING A REALISTIC INTERACTIVE VISUALIZATION MODEL AND TESTING ITS EFFECTIVENESS IN COMMUNICATING FLOOD RISK(2014) Olsen, V. Beth K; Momen, Bahram; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This project advances the field of flood risk management by using technology to bridge the gap between science and local community decision-making. Currently, flood risk management meetings use a computer-assisted decision support system (DSS) to illustrate various flood scenarios and facilitate collaborative discussions among participants. The DSS is a set of sophisticated models structured by geographic information systems (GIS) technicians. This study proposed a "stakeholder-built" DSS. Stakeholders are defined here as those directly at risk of flooding. This method utilized improved user interface capabilities while retaining the technical rigor and robustness of a Nationally-recognized GIS software package. There are times when a simple model may serve as an introduction to GIS technology. There are also situations where the cost of the sophisticated models may place them out of reach. The stakeholder-built DSS was proposed as a compliment to the sophisticated models by providing greater access to a DSS for end-users. The stakeholder-built DSS, in which stakeholders construct their own models, uses realistic interactive visualization as a learning tool. Realistic visualization represents information using virtual reality. The intent is to trigger awareness of risk through emotional response to images. Stakeholders use interactive visualization when constructing the model. Awareness of the flood scenario is enhanced by the constant attention required of the model-builder as they make connections between hand-eye coordinated motions and the cognitive information they are modeling. Knowledge accumulates as multiple steps are completed. The effectiveness of the stakeholder-built DSS was tested during community flood risk management meetings in Federal Emergency Management Agency Region III, the mid-Atlantic area. A DSS based on a Nationally-recognized GIS software package was also tested to serve as a comparison. Data were collected in pre- and post-surveys and follow-up interviews. The stakeholder-built and national GIS software DSS both performed equally well in communicating knowledge of flood risk and risk-reduction options, resulting in significant learning outcomes. To maximize the intent by stakeholders to take actions to reduce risk, meetings using the stakeholder-built DSS in high-quality meeting facilities performed best. In addition, the stakeholder-built model was less expensive and found to be more user-friendly for stakeholders.Item Essays on Migration and Health(2013) Knaup, Amy E.; Betancourt, Roger; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Migration is often thought of as a risky endeavor in which a migrant trades a known low return for an unknown but potentially higher return. However, migration has been empirically linked to insurance mechanisms through remittances. Chapter 1 unifies the risk-taking and insurance-seeking behaviors of migration into a single framework by framing the migration decision as one of income diversification in which multiple agents within a household to decide whether or not to migrate. Each migration strategy (no migration, partial migration, and full household migration) has its associated risks which are weighed against the returns the household could gain through choice of that particular migration strategy. I test the framework by estimating the probability of each migration strategy for Indonesian households during the period 1993-1998. The framework performs reasonably well in the case of urban households. However, the framework's predictions do not hold as well for rural households, which may be linked to the fact that they function within a larger insurance network than the nuclear family. In Chapter 2, I find that the response of return migration to GDP per capita can differentiate migrants who are seeking increased consumption for their household (i.e., consumption-oriented migrants) from migrants with intentions to invest at origin (i.e., investment-oriented migrants). Each type of migrant should have differential responses to GDP per capita at destination and may have differential responses to GDP per capita at origin. Using data on Mexican households between 1992-2002, I show that migrants returning from the USA exhibit characteristics of consumption-oriented migrants and migrants returning from internal locations exhibit characteristics of investment-oriented migrants. Chapter 3 is a published work in collaboration with Sandra Decker, Jalpa Doshi, and Daniel Polsky which uses Medicare claims data linked to two different surveys--the National Health Interview Survey and the Health and Retirement Study--to describe the relationship between insurance status before age 65 years and the use of Medicare-covered services beginning at age 65 years. Although we do not find statistically significant differences in Medicare expenditures or in the number of hospitalizations by previous insurance status, we do find that individuals who were uninsured before age 65 years continue to use the healthcare system differently from those who were privately insured.Item RISKY BUSINESS: CHANCE AND CONTINGENCY IN AMERICAN ART AROUND 1900(2012) Greenhalgh, Adam Robert; Promey, Sally M.; Kelly, Franklin; Art History and Archaeology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)My dissertation exposes and interprets unnoticed points of intersection between American visual culture and the rhetoric, logic, and imagery of institutions and disciplines dedicated to rationalizing chance--insurance, census, statistics, probabilism--around 1900, when popular, mathematical, and philosophical conceptions of the accident were undergoing considerable revision. Following the Civil War, experts in a number of disciplines and commercial enterprises counted, measured, and classified individual experiences, bodies, and lives. Statistically minded theorists recognized that, given a large enough sample, phenomena previously considered random or divinely predetermined, such as death, injury, accident, disease, and crime, occurred regularly and were, to a degree, predictable. Anthropometrists also noticed that anatomical and physiognomic traits were distributed according to statistically evident norms. Innovative graphic techniques were developed to visualize, dramatize, and publicize the previously invisible trends, laws, and patterns revealed by such statistical analysis. Insurance underwriters gathered vital statistics and compiled actuarial charts, effectively quantifying lives and configuring individuals in terms of risk. Insurance advertisements portrayed the modern world as a place of hazard and imminent peril manageable only through accident and life coverage. My dissertation demonstrates that this statistical and actuarial calculus manifested in works of art as Americans began to think, speak, and visualize their world in terms of risk, odds, and contingency. Organized as a series of case studies, my work demonstrates that visual culture fully engaged with the abstract concepts--chance, risk--and mathematical disciplines--statistics, probabilism--that informed this emergent worldview. My study builds on recent social histories of chance, enhancing and complicating them by considering understudied imagery--insurance advertising; composite photography; statistical graphics--and period documents overlooked by art historians--census questionnaires; actuarial life tables; Edward Bellamy's 1888 novel Looking Backward--to reveal not only how this material informs major artworks, but also how works of art participated in underwriting an emerging conception of the world as an ultimately indeterminate, chance-based system. Individual chapters focus on artworks clustered roughly around the year 1900: Winslow Homer's mid-1880s paintings of peril at sea, blurry pictorial photographic portraiture by Edward Steichen, and George Bellows's painting Forty-two Kids (1907).Item Using dredged material to restore the Chesapeake Marshlands Complex: Preliminary application of a risk-based optimization model for comparing placement options(2010) Shearin, Charlotte Bruce; King, Dr. Dennis M.; Marine-Estuarine-Environmental Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Using dredged material to restore wetlands in the Chesapeake Marshlands Complex (CMC) could offer solutions to two separate problems: 1) restoring and protecting the marshes in the CMC; and 2) finding an innovative reuse for dredged material from the Chesapeake Bay approach channels. The risk-based optimization model presented here assesses and compares restoration options for two alternative years (2023 and 2036) when the project may begin and represents a preliminary screening of material placement locations. Restoration of Zones 2a (Barbados Island) and 2b (Confluence Area) appear to provide significant environmental benefits, suggesting that restoration at these locations would provide the best return on investment. Low marsh restoration also provides a significant amount of benefits accrued. Based on sensitivity analysis, it appears that the choice of when to begin the project also represents tradeoffs between onsite habitat benefits and recreational benefits. Model results should be interpreted cautiously, considering the model limitations.Item Automatic Generation of Generalized Event Sequence Diagrams for Guiding Simulation Based Dynamic Probabilistic Risk Assessment of Complex Systems(2007-11-27) Nejad-Hosseinian, Seyed Hamed; Mosleh, Ali; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Dynamic probabilistic risk assessment (DPRA) is a systematic and comprehensive methodology that has been used and refined over the past two decades to evaluate the risks associated with complex systems such as nuclear power plants, space missions, chemical plants, and military systems. A critical step in DPRA is generating risk scenarios which are used to enumerate and assess the probability of different outcomes. The classical approach to generating risk scenarios is not, however, sufficient to deal with the complexity of the above-mentioned systems. The primary contribution of this dissertation is in offering a new method for capturing different types of engineering knowledge and using them to automatically generate risk scenarios, presented in the form of generalized event sequence diagrams, for dynamic systems. This new method, as well as several important applications, is described in detail. The most important application is within a new framework for DPRA in which the risk simulation environment is guided to explore more interesting scenarios such as low-probability/high-consequence scenarios. Another application considered is the use of the method to enhance the process of risk-based design.Item Essays On Labor Economics: Human Capital Risk And Labor Market Outcomes And Learning By Doing In Medicine(2006-06-06) Tristao, Ignez Miranda; Rust, John P.; Sanders, Seth; Economics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This dissertation consists of two essays. In the first essay I show that there are substantial differences in unemployment durations and reemployment outcomes for workers coming from different occupations. I argue that this variation can be explained by differences in occupational employment risk, arising from two sources: (1) the diversification of occupational employment across industries; and (2) the volatility of industry employment fluctuations, including sectoral co-movements. I define and estimate a measure of occupational employment risk (OER), which I relate to unemployment durations and wage losses. My results indicate that unemployed workers in high employment risk occupations, as defined by the OER measure, have 5 percent lower hazard ratios of leaving unemployment to a job in the same occupation and have 5 percent higher wage losses upon reemployment than workers in low OER occupations. Among occupational switchers, workers in higher OER occupations have 11.5 percent higher wage losses than workers in lower OER occupations. In my second essay, I and my co-authors estimate the effect of physician's experience on health outcomes. It is a common belief that experience can improve the level of skills, which suggests that there may be some learning by doing with practice. Economists have tried to empirically determine the existence of learning by doing in the medical area, because of its important policy implications. However, it is difficult to define and measure health outcomes since they are affected by patient selection and underlying conditions, making it hard to disentangle learning by doing from other effects. In this paper, we use a 'clean-cut' medical procedure that allows us to overcome those confounding issues. We use refractive eye surgery, an operation with a well-defined eligibility criterion and objective measures of previous condition and posterior outcome, which depend minimally on post-surgical care. The data used in the study is a two-year longitudinal census of refractive surgery patients collected by us from individual patients' chart. We find that the learning is coming more from the improvement in the surgical center's ability to translate the surgical plan into the desired eyesight correction rather than from the accumulation of the physician experience.