161 research outputs found
Understanding the Gender Gap in Computer Science Undergraduate Academics
There is a gender gap in technical fields that has persisted through generations. In my research, I focus on the gender gap within computer science (CS) undergraduate academics. Diversity in technical fields starts with diversity in academics. Studies have shown that girls who are exposed to CS in or before high school are more likely to study CS in college. [1] Other factors such as role models, life goals, and perception of CS also influence a girlâs decision. I surveyed UMW students in different stages of their CS degrees, in addition to students who only participated in an introductory CS class.
Most students entering introductory computer science classes today use smartphones, laptops, and tablets in their everyday lives. The intuitive user interfaces and natural comfort with technology could be shielding young people from considering how their devices work. Many young people use their devices for social media which could be shifting the perception of CS. A common opinion is that after a student finishes high school, their decision to take a CS class becomes less malleable. There may be steps that universities can take to increase exposure and encourage first year students to try a CS class. Biases from parents, other family members and non-familial figures (teachers, club leaders, etc.) can be passed through generations and change a studentâs self-perception.
In my paper, I discuss factors that influence UMW students based on analysis of the data collected from an online survey of UMW undergraduates. I will be presenting my findings and attempt to describe the causes and possible solutions for the gender gap
Mathematical models for the synthesis and optimization of spiral bevel gear tooth surfaces
The geometry of spiral bevel gears and to their rational design are studied. The nonconjugate tooth surfaces of spiral bevel gears are, in theory, replaced (or approximated) by conjugated tooth surfaces. These surfaces can be generated by two conical surfaces, and by a conical surface and a revolution. Although these conjugated tooth surfaces are simpler than the actual ones, the determination of their principal curvatures and directions is still a complicated problem. Therefore, a new approach, to the solution of these is proposed. Direct relationships between the principal curvatures and directions of the tool surface and those of the generated gear surface are obtained. With the aid of these analytical tools, the Hertzian contact problem for conjugate tooth surfaces can be solved. These results are useful in determining compressive load capacity and surface fatigue life of spiral bevel gears. A general theory of kinematical errors exerted by manufacturing and assembly errors is developed. This theory is used to determine the analytical relationship between gear misalignments and kinematical errors. This is important to the study of noise and vibration in geared systems
Kinematic precision of gear trains
Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory
Precision of spiral-bevel gears
The kinematic errors in spiral bevel gear trains caused by the generation of nonconjugate surfaces, by axial displacements of the gears during assembly, and by eccentricity of the assembled gears were determined. One mathematical model corresponds to the motion of the contact ellipse across the tooth surface, (geometry I) and the other along the tooth surface (geometry II). The following results were obtained: (1) kinematic errors induced by errors of manufacture may be minimized by applying special machine settings, the original error may be reduced by order of magnitude, the procedure is most effective for geometry 2 gears, (2) when trying to adjust the bearing contact pattern between the gear teeth for geometry 1 gears, it is more desirable to shim the gear axially; for geometry II gears, shim the pinion axially; (3) the kinematic accuracy of spiral bevel drives are most sensitive to eccentricities of the gear and less sensitive to eccentricities of the pinion. The precision of mounting accuracy and manufacture are most crucial for the gear, and less so for the pinion
Realism in Teaching Cybersecurity Research: The Agile Research Process
Part 1: Innovative MethodsInternational audienceAs global threats to information systems continue to increase, the value of effective cybersecurity research has never been greater. There is a pressing need to educate future researchers about the research process itself, which is increasingly unpredictable, multi-disciplinary, multi-organizational, and team-oriented. In addition, there is a growing demand for cybersecurity research that can produce fast, authoritative, and actionable results. In short, speed matters. Organizations conducting cyber defense can benefit from the knowledge and experience of the best minds in order to make effective decisions in difficult and fast moving situations. The Agile Research process is a new approach to provide such rapid, authoritative, applied research. It is designed to be fast, transparent, and iterative, with each iteration producing results that can be applied quickly. Purdue University is employing Agile Research as a teaching vehicle in an innovative, multi-university graduate program with government sponsor participation, as described in this paper. Because it simulates real-world operations and processes, this program is equipping students to become effective contributors to cybersecurity research
Black hole mass and velocity dispersion of narrow line region in active galactic nuclei and narrow line Seyfert 1 galaxies
Controversy regarding whether Narrow Line Seyfert 1 galaxies (NLS1s) follow
the same black hole --- galactic bulge relation as normal galaxies has been
raised by Mathur et al. (2001) and Ferrarese et al. (2001). In this paper, the
correlation between the black hole mass and the velocity dispersion of the
narrow line region, indicated by the [OIII] line width for a heterogeneous
sample of NLS1s, is examined. We show that the non-virial component subtracted
[OIII] width, which may well represent the stellar velocity dispersion
(), correlates with the estimated black hole mass , made using
the empirical law for broad line region sizefrom the reverberation mapping
measurements. Considering measurement errors, we find that the relation between
and the [OIII] width in active galactic nuclei (both NLS1s in this paper
and normal Seyferts in Nelson 2000) is consistent with that defined in nearby
hot galaxies (ellipticals and spiral bulge) but with more scatter. It seems
that there is no clear difference in the relation between and
(represented by the [OIII] width for AGN) in both NLS1s and normal broad line
active galactic nuclei from the same relation defined by nearby hot galaxies.Comment: 8 pages, including 2 figures, A&A accepte
Theory of Coexistence of Superconductivity and Ferroelectricity : A Dynamical Symmetry Model
We propose and investigate a model for the coexistence of Superconductivity
(SC) and Ferroelectricity (FE) based on the dynamical symmetries for
the pseudo-spin SC sector, for the displaced oscillator FE sector, and
for the composite system. We assume a minimal
symmetry-allowed coupling, and simplify the hamiltonian using a double mean
field approximation (DMFA). A variational coherent state (VCS) trial
wave-function is used for the ground state: the energy, and the relevant order
parameters for SC and FE are obtained. For positive sign of the SC-FE coupling
coefficient, a non-zero value of either order parameter can suppress the other
(FE polarization suppresses SC and vice versa). This gives some support to
"Matthias' Conjecture" [1964], that SC and FE tend to be mutually exclusive.
For such a Ferroelectric Superconductor we predict: a) the SC gap
(and ) will increase with increasing applied pressure when pressure
quenches FE as in many ferroelectrics, and b) the FE polarization will increase
with increaesing magnetic field up to . The last result is equivalent to
the prediction of a new type of Magneto-Electric Effect in a coexistent SC-FE
material. Some discussion will be given of the relation of these results to the
cuprate superconductors.Comment: 46 page
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