USMA Digital Commons (United States Military Academy, West Point)
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Expediting arithmetic automaticity: Do inefficient computation methods induce spontaneous testing effects?
No full textBefore achieving arithmetic automaticity (direct answer recall), learners self-compute answers or use calculators/tables. Mechanisms supporting arithmetic automaticity are of interest because automaticity predicts math achievement and employment outcomes. Future recall is enhanced when, during study, learners attempt to recall the to-be-learned information (“testing effect”). However, learners may not attempt retrieval when another strategy is available (computation, re-reading). We expected learners to more frequently attempt recall when the alternative strategy was inefficient. Participants learned novel arithmetic problems, and could recall answers (if able) or use a computation method, which varied by condition: (i) self-computation; (ii) calculator-computation; and (iii) using a calculator with scrambled keys. Final recall ability was highest after the condition with the most inefficient non-retrieval method (scrambled calculator). We assumed recall attempts preceded computation, but also considered parallel execution. As evidence against parallel retrieval, answer recall rarely interrupted computation (mental/calculator) after it began. Thus, learners should make pre-emptive recall attempts
The Cyber Domains: Understanding Expertise for Network Security
No full textFrom The Oxford Handbook of Expertise : In this chapter, we describe the historical and continuing evolution of the cyber domains, and how we can operationalize current research in cyber expertise. Research into cyber expertise is in its infancy; in fact, there is no clear definition of what constitutes cyber expertise or how it may be unique when compared to other technical fields. We describe the work roles of cyber operators and review results from Cognitive Task Analyses of their workplace. We then review several paradigms in detail including experiments using simulated intrusion detection software to study different levels of expertise and how information is shared between multiple teammates in these environments. Finally, we present some candidate topics for future research including the use of realistic synthetic environments to study cyber operations with more ecological validity.https://digitalcommons.usmalibrary.org/aci_books/1012/thumbnail.jp
US Army Performance Appraisal Policy Analysis: A Simulation Optimization Approach
No full textAn effective performance appraisal system is critical in identifying officers with the knowledge, skills, and abilities to lead the future military force. The US Army uses a forced distribution performance appraisal system that limits the number of above average evaluations raters can award to their subordinates. Aside from job performance, multiple factors contribute to the rating an individual receives in such systems. These factors include a rater’s span of control (the number of subordinates being rated), the frequency at which individuals change raters, regulatory constraints pertaining to the number of top evaluations a rater can award, and the rater behavior. Using performance appraisal data provided by the US Army Human Resources Command, we develop a discrete-event simulation model that represents Army officers in the current forced distribution performance appraisal system. We then apply ranking and selection simulation optimization techniques to evaluate and optimize controllable input parameters in the simulated system. Our results show the potential of reducing the number of officers not receiving the number of above average evaluations commensurate with their performance level by as much as 24%. The results also further indicate the general applicability of simulation optimization in the fields of manpower modeling and policy analysis
Magnetic Resonance Thermometry: An Emerging Three-dimensional Temperature Diagnostic Technique
No full textUndergraduate Internal Flow Convection Heat Transfer Laboratory
No full textAn experimental apparatus was designed, built, tested, and implemented as a laboratory experience in an undergraduate heat transfer course at the United States Military Academy at West Point. Four different tube configurations demonstrate for students internal flow convection heat transfer fundamentals using straight and coiled thin-walled, circular tubes with valves and a large ice bath tank. The apparatus is instrumented with thermocouples and a data acquisition system. As part of the laboratory experience, students measure, collect and analyze data, compare experimental results to theory, and assess error and uncertainty. This simple convection laboratory provides realistic, hands-on experience with an experimental apparatus, a laboratory procedure, instrumentation, and engineering technicians − all of which help students gain physical understanding of thermal-fluids concepts and develop professionally
Contaminant Dispersion Validation Simulations for an Urban Inspired Scenario
No full textThe atmospheric dispersion of contaminants in the wake of a large urban structure is a challenging fluid mechanics problem of interest to the scientific and engineering communities. Magnetic Resonance Velocimetry (MRV) is a relatively new technique that leverages diagnostic equipment used primarily by the medical field to make 3D engineering measurements of water flow and contaminant dispersal. SIERRA/Fuego, a computational fluid dynamics (CFD) code at Sandia National Labs is employed to make detailed comparisons to the dataset to evaluate the quantitative and qualitative accuracy of the model. The comparison exercise shows good comparison between model and experimental results, with the wake region downstream of the tall building presenting the most significant challenge to the quantitative accuracy of the model. Model uncertainties are assessed through parametric variations. Some observations are made in relation to the future utility of MRV and CFD, and some productive follow-on activities are suggested that can help mature the science of flow modeling and experimental testing
Feasibility Study for a MEDEVAC Electric UAS Capability
No full textThis study examines the feasibility of integrating medical subsystems into an existing Unmanned Aircraft System (UAS) platform to facilitate medical evacuation (MEDEVAC) from combat environments. The implementation of a MEDEVAC-capable UAS is found to be a feasible and logical expansion of current MEDEVAC assets. A comprehensive review of current fully- or semi-autonomous electric vertical takeoff and landing (eVTOL) UAS technologies is conducted to select a candidate aircraft. A conceptual design of the MEDEVAC UAS, configured with equipment needed to sustain a casualty during evacuation is created. The smaller form factor of the system opens the opportunity to pre-deploy MEDEVAC assets to forward combat posts, improve response times, and offer evacuation options when manned assets are denied. The predicted range performance of the system supports such a concept of operation
Three Dimensional Velocity And Temperature Field Measurements Of Internal And External Turbine Blade Features Using Magnetic Resonance Thermometry
No full textMagnetic resonance thermometry (MRT) is a maturing diagnostic tool used to measure three-dimensional temperature fields. It has a great potential for investigating fluid flows within complex geometries leveraging medical grade magnetic resonance imaging (MRI) equipment and software along with novel measurement techniques. The efficacy of the method in engineering applications increases when coupled with other well-established MRI-based techniques such as magnetic resonance velocimetry (MRV). In this study, a challenging geometry is presented with the direct application to a complex gas turbine blade cooling scheme. Turbulent external flow with a Reynolds number of 136,000 passes a hollowed NACA-0012 airfoil with internal cooling features. Inserts within the airfoil, fed by a second flow line with an average temperature difference of 30 K from the main flow and a temperature-dependent Reynolds number in excess of 1,800, produces a conjugate heat transfer scenario including impingement cooling on the inside surface of the airfoil. The airfoil cooling scheme also includes zonal recirculation, surface film cooling, and trailing edge ejection features. The entire airfoil surface is constructed of a stereolithography resin—Accura 60—with low thermal conductivity. The three-dimensional internal and external velocity field is measured using an MRV. The fluid temperature field is measured within and outside of the airfoil with an MRT, and the results are compared with a computational fluid dynamics (CFD) solution to assess the current state of the art for combined MRV/MRT techniques for investigating these complex internal and external flows. The accompanying CFD analysis provides a prediction of the velocity and temperature fields, allowing for errors in the MRT technique to be estimated
Russian Society and Foreign Policy: Mass and Elite Orientations After Crimea
No full textMost Russians applaud the official narrative that Russia has re-emerged as a great power under Vladimir Putin, particularly with the annexation of Crimea, and also agree with the claims of the Russian state that America is an unfriendly power. Yet they increasingly disagree with the assertions of the Kremlin that the United States is a looming external danger and a subversive force in Russian domestic politics. In line with these opinions, many Russians are unwilling to bear the economic burden of an escalating confrontation with the West, demonstrating the initially limited and now waning political significance of the “Crimea euphoria” (or “Crimea effect”) and the “rally ‘round the flag” phenomena generated by the annexation of 2014 and ensuing tensions with the West.
Russian elites often differ from the general public in their stronger backing for a more assertive foreign posture. Nevertheless, such preferences are often moderated by a preoccupation with socio-economic problems at home and by the apprehension that Russia will neglect domestic modernization indefinitely if its foreign policy is confrontational. Like Russian mass publics, Russian elites often view the external environment as dangerous, a perception that is cultivated by the Kremlin to help produce patriotic “rally” sentiments. Yet this “rally” effect is dulled by the widespread belief among both elites and masses that the greatest threats to Russia are rooted in its social and economic underdevelopment.
Russian society often finds domestic problems much more worrisome than U.S. military power or a “color revolution” fomented by the West, both of which the Kremlin has framed as important threats in its efforts to mobilize domestic supporters and isolate opponents. Drawing extensively on opinion surveys in Russia, the paper concludes that a majority of Russians are likely to believe that the Kremlin should not emphasize costly policies intended to counter U.S. military power or other potential American threats
Effects of YouTube Video as Pre-Lecture Preparation
Get PDFClassroom lectures convey course concepts more effectively when students have prepared in advance. Traditionally, students prepare for lectures by reading the course textbook. Textbooks are the default study material for most educational courses; however, some technical subjects are better conveyed in video format. Therefore, in this study, we encouraged students to supplement their learning resources with web-based video tutorials that provide detailed demonstrations with the respect to technical network configuration and management. YouTube is a video sharing website that can provide free educational tutorials and instructions on technical subject matter, where students can observe practical human-machine interaction to prepare for lectures and increase overall course performance on exams, assignments, and laboratory projects. Our goal was to compare the overall performance as well as the level of active class participation between two groups of the same computer networking course. We found that the group that used YouTube videos for pre-lecture preparation scored approximately 3% higher on exams but 5% lower on homework assignments than the control group (textbook only). There was no statistical significance between the two groups with respect to overall course grades. Study habits and degree of class participation of each student correlated more strongly with overall course performance than whether the student viewed the videos