Doctor of Philosophy

dissertationUsing eye-tracking technology to capture the visual scanpaths of a sample of laypersons (N = 92), the current study employed a 2 (training condition: ABCDE vs. Ugly Duckling Sign) Ã- 2 (visual condition: photorealistic images vs. illustrations) factorial design to assess whether SSE training succeeds or fails in facilitating increases in sensitivity and specificity. Self-efficacy and perceived importance were tested as moderators, and eye-tracking fixation metrics as mediators, within the framework of Visual Skill Acquisition Theory (VSAT). For sensitivity, results indicated a significant main effect for visual condition, F(1,88) = 7.102, p = .009, wherein illustrations (M = .524, SD = .197) resulted in greater sensitivity than photos (M = .425, SD = .159, d = .55). For specificity, the main effect for training was not significant, F(1,88) = 2.120, p = .149; however, results indicated a significant main effect for visual condition, F(1,88) = 4.079, p = .046, wherein photos (M = .821, SD = .108) resulted in greater specificity than illustrations (M = .770, SD = .137, d = .41). The interaction for training Ã- visual condition, F(1,88) = 3.554, p = .063, was significant within a 90% confidence interval, such that those within the UDS Photo condition displayed greater specificity than all other combinations of training and visual condition. No significant moderated mediation manifested for sensitivity, but for specificity, the model was significant, r = .59, R2 = .34, F(9,82) = 4.7783, p =.001, with Percent of Time in Lookzone serving as a significant mediator, and both self-efficacy and visual condition significantly moderating the mediation. For those in the photo condition with very high self-efficacy, UDS increased specificity directly. For those in the photo condition with self-efficacy levels at the mean or lower, there was a conditional indirect effect through Percent of Time in Lookzoneâ€"which is to say that these individuals spent a larger amount of their viewing time on target (observing the atypical nevi)â€"and time on target is positively related to specificity. Findings suggest that existing SSE training techniques may be enhanced by maximizing visual processing efficiency

In situ propellant production: Alternatives for Mars exploration

Current planning for the Space Exploration Initiative (SEI) recognizes the need for extraterrestrial resources to sustain long-term human presence and to attain some degree of self-sufficiency. As a practical matter, reducing the need to carry large supplies of propellant from Earth will make space exploration more economical. For nearly every round trip planned with conventional propulsion, the actual payload is only a small fraction - perhaps 10-15 percent - of the mass launched from Earth. The objective of this study was to analyze the potential application for SEI missions of propellants made exclusively from lunar or martian resources. Using such propellants could minimize or eliminate the cost of carrying propellant for surface excursion vehicles and return transfers through two high-energy maneuvers: Earth launch and trans-Mars injection. Certain chemical mono- and bipropellants are candidates for this approach; they could be recovered entirely from in situ resources on the Moon and Mars, without requiring a continuing Earth-based resupply of propellant constituents (e.g., fuel to mix with a locally obtained oxidizer) and, perhaps, with minimal need to resupply consumables (e.g., reagents or catalyst for process reactions). A complete assessment of the performance potential of these propellants must include the requirements for installation, operations, maintenance, and resupply of the chemical processing facility

Three-Dimensional Velocity Measurements Around and Downstream of a Rotating Vertical Axis Wind Turbine

Modern designs for straight-bladed vertical axis wind turbines (VAWTs) feature smaller individual footprints than conventional horizontal axis wind turbines (HAWTs), allowing closer spacing of turbines and potentially greater power extraction for the same wind farm footprint. However, the wakes of upstream turbines could persist far enough to affect the performance of closely-spaced downstream turbines. In order to optimize the inter-turbine spacing and to investigate the potential for constructive aerodynamic interactions, the complex dynamics of VAWT wakes should be understood. The full three-component mean velocity field around and downstream of a scaled model of a rotating VAWT has been measured by Magnetic Resonance Velocimetry (MRV). The model turbine has an aspect ratio (height/diameter) of 1, and was operated in a water facility at subscale but still turbulent Reynolds number of 11,600 based on the turbine diameter. The main flow features including recirculation bubble sizes and strong vortex structures are believed to be representative of flow at full scale Reynolds number. To have kinematic similarity with a power-producing turbine, the model turbine was externally driven. Measurements were taken with the turbine stationary and while driven at tip speed ratios (TSRs) of 1.25 and 2.5, realistic values for VAWTs in operation. The MRV measurement produced three-dimensional velocity data with a resolution of 1/50 of the turbine diameter in all three directions. The flow is shown to be highly three dimensional and asymmetric for the entirety of the investigated region (up to 7 diameters downstream of the turbine). The higher TSR produced greater velocity defect and asymmetry in the near wake behind the turbine, but also showed faster wake recovery than the slower TSR and stationary cases. Wake recovery is affected by a counter-rotating vortex pair generated at the upwind-turning side of the turbine, which mixes faster fluid from the free stream in with the wake. The strength of vortices is shown to increase with TSR

Winter Wheat Test Results for South Dakota, 2002

The winter wheat variety recommendations for 2003 are listed in table 1. Comments: The dominant issue facing South Dakota agriculture in the 2002 crop season was the lack of moisture in the fall of 2001 and the winter and spring of 2002. Limited moisture led to a large deficit in subsoil moisture in many cropping regions of the state. This in turn resulted in many acres of winter wheat and other small grains being harvested for hay. The average winter wheat yield in the South Dakota Crop Performance Testing (CPT) Program was 39 bu/A for year 2002 and 48 bu/A for the 3-year period (2000-2002). Compared to 2001, this was a drop of 7 bu/A in both the 1- and 3-year CPT yield averages

A Journey through the Development of a DH Program for Undergraduates

In institutions that do not actively integrate DH into the curriculum, introducing undergraduates to DH tools and methods can be difficult. However, Gettysburg College has facilitated a summer research experience for undergraduates. This interactive workshop will introduce participants to the Digital Scholarship Summer Fellowship program and provide a high-level overview of its development and implementation. Workshop leaders will provide guidance on developing a summer program tailored to participants\u27 institution\u27s needs and aspirations. Participants will come away with strategies for identifying stakeholders and partners, developing program goals, selecting digital tools, designing workshops, and methods to incorporate aspects of assessment and sustainability

A Journey through the Development of a DH Program for Undergraduates

In institutions that do not actively integrate DH into the curriculum, introducing undergraduates to DH tools and methods can be difficult. However, Gettysburg College has facilitated a summer research experience for undergraduates. This interactive workshop will introduce participants to the Digital Scholarship Summer Fellowship program and provide a high-level overview of its development and implementation. Workshop leaders will provide guidance on developing a summer program tailored to participants\u27 institution\u27s needs and aspirations. Participants will come away with strategies for identifying stakeholders and partners, developing program goals, selecting digital tools, designing workshops, and methods to incorporate aspects of assessment and sustainability

Development of RGB Composite Imagery for Operational Weather Forecasting Applications

No abstract availabl