The role of topography on the spatial distribution of tornadoes was assessed through geospatial and statistical techniques. A 100-m digital elevation model was used to create slope, aspect, and surface roughness maps; and; tornado beginning and ending points and paths were used to extract terrain information. Tornado touchdowns, liftoffs, paths, and path-land angles were examined to determine whether tornado paths occur more frequently in or along certain terrain or slopes. Statistical analyses, such as bootstrapping, were used to analyze tornado touchdowns, liftoffs and paths and path-relative terrain angles. Results show that tornado paths are more common with downhill-movement. Tornadoes are not as likely to move uphill because the 73.6 percent northeast path bias represents the highest frequencies of path-angles. Tornado touchdowns and paths occur more often in smooth terrain, rather than rough terrain. Complex topographic variability seems to not have an effect on the spatial distribution of tornadoes.

The motivation behind the project was to update the Livermore Software Technology Corporation (LSTC) Hybrid III 95th percentile finite element model, such that the neck assembly response under varying simulated loading conditions equals that of the federally regulated Hybrid III 95th percentile anthropomorphic testing device (ATD). The family of Hybrid III crash test dummies approximate the physical properties and response of the human body in a frontal automotive crash. The Hybrid III is used to assess the effectiveness of vehicle restraint systems. LSTC offers Hybrid III finite element models for use in their Multiphysics simulation software package, LS-DYNA. The Hybrid III models are used as cost-effective alternative to physical crash tests in the development of vehicle crashworthiness. However, the neck response of the LSTC Hybrid III 95th percentile model in simulation was poorly correlated to that of the physical Hybrid III neck in corresponding tests. The source of the dissimilarity was inadequate dimensions, element behavior, and material properties of the neck. To improve correlation to the physical ATD, a number of modifications were made to the LSTC Hybrid III 95th percentile neck. Development of the neck model began with improvements in mass and geometry. Element formulation and element discretization were altered to improve model durability and accuracy. A mesh convergence study and simulation under extreme-severity loading were completed to validate the foregoing model alterations. Test data from a physical compression test and NASA-performed Neck Sled Tests were collated with data from simulation to adjust material type and material properties. The model was further calibrated according to Code of Federal Regulations neck calibration test response requirements. The resulting neck model developed in LS-DYNA exhibited improved dynamic characteristics and reliability under both low and high-severity loading. Computational efficiency was enhanced along with model tendency to normally terminate under excessive loading. The updated model moreover demonstrated consistent element behavior and realistic feedback in bending. The revised neck model will be adopted by NASA for use in predicting potential occupant injury during spacecraft landing. A similar model with reworked material properties attuned to higher loading will be implemented into the full consumer version of the Hybrid III 95th percentile model for employment in high-severity frontal crash simulation.

The application of geographic information systems was used to map obesogenic conditions by zip code tabulation areas in Durham County, North Carolina and evaluated associations between those conditions and the understudied area of early childhood obesity. Of the thirty one percent of the children in Durham County, North Carolina who were considered obese in 2010, four hundred and thirty three (1:5) 2 - 4 year old children who received supplemental nutrition services for women, infants and children were obese with BMI levels greater or equal to the 95th percentile and were used as the criterion variable in the study (N=433). The study's research questions examined conditions of the neighborhood that impeded the weight status of young children. The theoretical framework included the environmental stress, socioeconomic, multiple exposures-multiple effects, and attachment theories. The twenty - six variables used in this secondary quantitative study included demographics on socioeconomic and education levels, home occupancy and vacancy rates, age of homes, and neighborhood accessibility features: access to parks; recreation facilities; grocery stores verses convenience stores; fast food restaurants; medical facilities; schools; day cares; and neighborhood incivilities such as numbers of reported crimes. The t - test were configured as Grouping Variables with the cut-point of 18.7% and with an Alpha of .05 and produced statistical significance on five of twenty - six variables. A mean rate of 19.3% yielded statistical significance on ten of twenty - six variables. The Levene's Test for Equality of Variances expressed assumptions on scores met for statistical significance on t-test at the Alpha = 0.05 level for twenty - four of the twenty - six variables. The results of this study would possibly increase the use of the innovative geographic information systems to inform policy decisions, environmental interventions and environmental design on obesogenic correlates between the understudied area of early childhood obesity and the built environment.