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Good Students are Good Students: Student Achievement with Visual versus Textual Programming
Full text linkIn this full research paper, we compare the impact of learning a visual versus textual programming language in an introductory computing course that is a general education requirement at our institution. We conducted a randomized comparative study with "experimental" sections that were taught using Python instead of RAPTOR, a flowchart-based programming language. The populations of students learning each programming language were similar with respect to gender, race, and predicted performance based upon standardized test scores and prior post-secondary education. Although students' performance on the whole was similar regardless of the programming language taught, predicted performance is correlated with SAT Math scores, grades in mathematics courses (specifically Calculus II), and, for lower-performing students, grades in other courses that satisfy general education requirements. That is, students from these groups who had lower predicted performance and learned Python performed worse on average than their peers who learned RAPTOR, and students with higher predicted performance outperformed (on average) their peers who learned RAPTOR. In addition, students' performance in subsequent computer science courses was not correlated with their performance and the language they learned in our introductory computing course. Our results raise important questions about the role of an introductory computing course in promoting equity and engaging students from historically underrepresented groups in computing fields
A Probabilistic Approach to Assess Slope Stability of Roadway Shoulders Under Superheavy Traffic Operations
No full textNon-conventional Super Heavy Load (SHL) units generally transport heavy loads weighing significantly higher than conventional trucks. Movements of such SHL trailer units with overweight tires and non-generic axle assemblies are detrimental to the structural integrity of sloped roadway shoulders. This research proposes an approach to realistically evaluate stability of roadway shoulders under subjected to SHL units. The developed methodology upgrades conventional Limit Equilibrium Method to a probabilistic approach to consider uncertainties attributed to orthogonal stiffness characteristics of aggregate materials in pavement structures. The proposed novel approach is also capable of assessing complex traffic loads imparted under SHLs. To achieve these objectives, the researchers first developed a field-testing scheme to obtain prominent features associated with the SHL trailer units and their loading configurations, as well as pavement material and road shoulder characteristics for ten overweight corridors in Texas. The field-derived information was then used as inputs in a series of 3D finite element model to characterize SHL-induced forces. Monte-Carlo methods was also deployed to establish a distribution of shear strength factors, within the bounds of laboratory-derived data for base and subbase layers as well as subgrade soils. Eventually, the resisting forces were contrasted with mobilizing forces along failure surfaces to assess stability of pavement shoulders. Results underscored the importance of tire load magnitude, shoulder slope inclination, surface treatment, and moisture management mechanisms in stability studies of roadway shoulders under demanding stress paths in overweight routes. The permutations pertaining to extreme weather events such as flooding, heavy rainfall, and prolonged inundation events also showed the detrimental effect of SHL operations on the stability of sloped shoulders. The proposed approach and synthesized results for Texas SHL corridors provided in this research facilitate realistic evaluation of the potential failure risk of sloped shoulders under SHL operations, considering non-typical nature of SHLs, environmental factors, and unique features of roadway shoulders in such regions
System for Physically Defeating Unmannded Aerial Vehicles
Full text linkA system for defeating a threat unmanned aerial vehicle. The system includes a friendly unmanned aerial vehicle, a cap turing device configured to be suspended from the friendly unmanned aerial vehicle for arresting a threat unmanned aerial vehicle, and one or more load-limited release mechanisms for removably suspending a releasable portion of the capturing device from the friendly unmanned aerial vehicle. In certain embodiments, the load-limited release mechanisms are configured to release the entirety of the capturing device from the friendly unmanned aerial vehicle upon capture of the threat unmanned aerial vehicle. In other embodiments, the load limited release mechanisms are configured to release only a peripheral portion of the capturing device to reposition a captured unmanned aerial vehicle to a central portion of the capturing device for carrying the captured vehicle to a remote location
Delivery System for Unmanned Aerial Vehicles
Full text linkA system for deploying an unmanned aerial vehicle in a target region. The system includes a pod configured to be deployed from an air craft in a first region remote from the target region. The pod includes a capsule housing portion and a capsule ejection system in operative communication with the capsule housing portion. A capsule is dimensioned and configured to be disposed in the capsule housing portion as the pod is deployed from the aircraft and is ejected from the capsule housing portion by the capsule ejection system in a second region remote from the first region and the target region. The capsule includes a UAV housing portion dimen sioned and configured to encase the unmanned aerial vehicle and a UAV ejection system in operative communication with the UAV housing portion for deploying the unmanned aerial vehicle in the target region
A Probabilistic Approach to Assess Slope Stability of Roadway Shoulders Under Superheavy Traffic Operations
No full textNon-conventional Super Heavy Load (SHL) units generally transport heavy loads weighing significantly higher than conventional trucks. Movements of such SHL trailer units with overweight tires and non-generic axle assemblies are detrimental to the structural integrity of sloped roadway shoulders. This research proposes an approach to realistically evaluate stability of roadway shoulders under subjected to SHL units. The developed methodology upgrades conventional Limit Equilibrium Method to a probabilistic approach to consider uncertainties attributed to orthogonal stiffness characteristics of aggregate materials in pavement structures. The proposed novel approach is also capable of assessing complex traffic loads imparted under SHLs. To achieve these objectives, the researchers first developed a field-testing scheme to obtain prominent features associated with the SHL trailer units and their loading configurations, as well as pavement material and road shoulder characteristics for ten overweight corridors in Texas. The field-derived information was then used as inputs in a series of 3D finite element model to characterize SHL-induced forces. Monte-Carlo methods was also deployed to establish a distribution of shear strength factors, within the bounds of laboratory-derived data for base and subbase layers as well as subgrade soils. Eventually, the resisting forces were contrasted with mobilizing forces along failure surfaces to assess stability of pavement shoulders. Results underscored the importance of tire load magnitude, shoulder slope inclination, surface treatment, and moisture management mechanisms in stability studies of roadway shoulders under demanding stress paths in overweight routes. The permutations pertaining to extreme weather events such as flooding, heavy rainfall, and prolonged inundation events also showed the detrimental effect of SHL operations on the stability of sloped shoulders. The proposed approach and synthesized results for Texas SHL corridors provided in this research facilitate realistic evaluation of the potential failure risk of sloped shoulders under SHL operations, considering non-typical nature of SHLs, environmental factors, and unique features of roadway shoulders in such regions
The Hydrostatic Vacuum Tube: a Low-Cost Thermal Fluid Science Laboratory
Full text linkStudents often comment that they benefit from exposure to both analytical and experimental results of concepts discussed in class, especially in the abstract thermal-fluid sciences emphasis area of a Mechanical Engineering curriculum. As educators, we sought to address this deficiency by developing a new test apparatus, the Hydrostatic Vacuum Tube (HVT). In short, a HVT is a vertical tube partially filled with water and a trapped air pocket at the top, initially at atmospheric pressure. One experiment involves opening a valve at the bottom to expose an exit port of sufficiently small exit diameter to prevent backflow of air. Water is collected and measured until the flow stops due to the hydrostatic vacuum created as the air pocket expands. A second experiment (the Draining Tank) can be conducted without trapping the air, by exposing/venting the liquid surface to ambient pressure. The height of the water is measured versus time as the tank drains, driven by a hydrostatic head. Predictive theory is developed and results compared with experiment, with excellent agreement. Key thermodynamics concepts involved are expansion of an ideal gas, hydrostatic pressure, and mass conservation in a control volume. The device could be used in other courses, such as Fluid Mechanics, Engineering System Dynamics, Heat Transfer and Experimental Mechanics. Using the same lab equipment in several courses iteratively will make connections between subject areas. The construction and use of the lab hardware and relevant theory is discussed in this paper. Plans are outlined for assessment of the effectiveness of the lab in improving conceptual understanding of the technical content, broadening the experimental experience, and enhancing the ability to use appropriate technical language when comparing test data and theoretical predictions
Aztlan for the Middle Class: Chicano Literary Activism
No full textThis chapter examines the relationship between Mexican American literature and the strand of Chicano activism focused on the needs of the working class. By offering literary case studies, including Rudolfo A. Anaya’s novel Heart of Aztlan (1976), Arellano identifies how literary activism has diverged from these needs. Although literature could aid the plight of workers by enabling a group to recognize its solidarity, Arellano argues, the identity that Chicano literature consolidates is ultimately distinct from the working class as such. So even as Chicano literary activism tends to be presented as the cultural arm of a labor movement, such activism has instead operated as the psychic support for a growing Mexican American middle class. While it may seem as if the interests of this growing class are unified with the needs of Mexican American workers, a shared Chicano culture has not been able to address the economic problems that each class faces. It remains necessary to identify continually the difference between literary activism benefiting the middle class and a labor movement benefiting workers
REMINISCENCE AND DIGITAL STORYTELLING TO IMPROVE WELL-BEING OF OLDER ADULTS WITH COGNITIVE IMPAIRMENT
Full text linkTo address the growing concern about loneliness and diminished well-being among persons with cognitive impairment, an intergenerational intervention based on reminiscence and digital storytelling was offered by trained college student volunteers to older adults living in the community. A randomized controlled trial was used to assess the effects of the intervention. Younger and older adult participants were randomly paired and assigned to reminiscence (n=20) or control (social wellness, n=16) groups. Data were collected at baseline, mid-intervention, and at the end of the intervention. Friedman tests for non-normally distributed outcome variables and one-way repeated measures ANOVA for normally distributed outcome variables were conducted. Results showed that emotional loneliness, total social and emotional loneliness, quality of life, and positive affect significantly improved among older adults in the reminiscence group, especially between baseline and posttest. Results suggest that weekly intergenerational engagements with young adults benefit older adults with psychological well-bein
Risk Assessment of Underground Utilities Subjected to Super Heavy Load (SHL) Applications in Overload Corridors
No full textVehicles transferring super heavy load (SHL) typically weigh several folds of the permissible weight limits set forth by regulatory agencies. Movement of such vehicles with multi-axle trailers can adversely affect the structural integrity of utilities buried underneath the roadway surface. This was the motivation for the authors to devise an approach to assess the potential risk against failure of underground utilities subjected to SHL movements in overweight corridors. To achieve this objective, our research team initially deployed portable weight-in-motion devices to ten sites with high frequency of SHLs in Texas. Subsequently, non-destructive field tests such as falling weight deflectometer and ground penetrating radar were performed for back-calculation of the pavement layer moduli. As-built plans were further reviewed to extract the pertinent information on utility characteristics. Subsequently, the field-derived data were in turn incorporated into a 3D finite element code for the determination of vertical deflection of utility at the crown under SHL movement, with realistic considerations of the tire-pavement contact stress distributions and pipe-soil interactions. Ultimately, the SHL-induced vertical deflection of utility was contrasted with maximum allowable deformation measures to characterize factor of safety against failure. The numerical simulation results showed that operation of SHLs with heavy axles and tires can potentially jeopardize the structural integrity of underground utilities across the state right-of-way, particularly if placed at shallow depths. Accordingly, buried utility risk analysis should be an integral component in risk management studies of transportation facilities servicing SHLs in overload corridors. The synthesized results can provide means to ensure safe operation of SHLs in highway networks accommodating underground utilities