Online security, cryptography, and quantum computing

Most secure online transactions are handled using RSA encryption for key exchange to prevent interception of private information like credit card numbers, bank accounts, etc. Unfortunately, development of quantum computers could break RSA (and other encryption systems). I will speak about the problem and potential solutions if quantum computers become available

An Attempt to Get and Keep Women Involved in Physics

In this talk I will briefly review some of the obstacles to the full participation of women in the STEM disciplines. In order to increase the number of women in physics, computer science, and mathematics we have started a cohort-based program with curricular and scholarship components for women in these majors. I will present the results of our program so far and offer some advice based on our experiences

Stereodeficient subjects demonstrate non-linear stereopsis

AbstractThere appear to be two modes of stereoscopic processing: a conventional linear operation that is dependent on correspondence between local luminance components in the two eyes’ views, and a non-linear or second-order processing mode. This second mode may use disparity information provided by particular ‘non-Fourier’ features of the stimulus such as the contrast envelope. Preliminary results suggest that people who fail standard clinical stereotests are able to extract non-linear disparity information from Gabor stimuli [McColl & Mitchell, 1998. Vision Research, 38, 1889–1900]. Here we evaluate the status of the non-linear mechanism in such individuals by using two types of contrast enveloped stimuli, namely random line and Gabor micropatterns, in a task that requires near/far depth judgements [Ziegler & Hess, 1999. Vision Research, 39, 1491–1507]. Although our sample was small, three of our four subjects who had performed poorly on at least one standard clinical test of stereopsis could perform the task, as well as one ‘stereoblind’ subject who had failed all four standard clinical tests. The overall results suggest that individuals with stereoanomalies show a diversity of deficits, but some nevertheless can see depth using ‘non-linear’ mechanisms

Variable Selection when Confronted with Missing Data

Variable selection is a common problem in linear regression.Stepwise methods, such as forward selection, are popular and areeasily available in most statistical packages. The models selectedby these methods have a number of drawbacks: they are oftenunstable, with changes in the set of variable selected due to smallchanges in the data, and they provide upwardly biased regressioncoefficient estimates. Recently proposed methods, such as the lasso,provide accurate predictions via a parsimonious, interpretablemodel.Missing data values are also a common problem, especially inlongitudinal studies. One approach to account for missing data ismultiple imputation. The simulation studies were conducted comparingthe lasso to standard variable selection methods under differentmissing data conditions, including the percentage of missing valuesand the missing data mechanism. Under missing at random mechanisms,missing data were created at the 25 and 50 percent levels with twotypes of regression parameters, one containing large effects and onecontaining several small, but nonzero, effects. Five correlationstructures were used in generating the data: independent,autoregressive with correlation 0.25 and 0.50, and equicorrelatedagain with correlation 0.25 and 0.50. Three different missing datamechanisms were used to create the missing data: linear, convex andsinister. These mechanismsLeast angle regression performed well under all conditions when thetrue regression parameter vector contained large effects, with itsdominance increasing as the correlation between the predictorvariables increased. This is consistent with complete datasimulations studies suggesting the lasso performed poorly insituations where the true beta vector contained small, nonzeroeffects. When the true beta vector contained small, nonzero effects,the performance of the variable selection methods considered wassituation dependent.Ordinary least squares had superior performance in terms confidenceinterval coverage under the independent correlation structure andwith correlated data when the true regression parameter vectorconsists of small, nonzero effects. A variety of methods performedwell when the regression parameter vector consisted of large effectsand the predictor variables were correlated depending on the missingdata situation

MapCores 2012-2013 Assessment Report

This is a report showing the assessment results for the MapCores (MAthematics, Physics, COmputer science REsearch Scholars) program at the College of Saint Benedict. Started in 2009, MapCores is a cohort-based program designed to increase women\u27s interest and achievement in mathematics, physics, computer science and engineering. The report was submitted for the National Science Foundation grant number 0965705

A Women in Mathematics, Computer Science, and Physics Course

Increasing women\u27s participation is a concern in disciplines beyondphysics. As part of our Mathematics, Physics, Computer ScienceResearch Scholars (MapCores) program, we teach a women in scienceclass covering these three areas. Our course is a special version ofour college\u27s first year seminar, which is a course designed toprepare our students to read, write, and speak at a college-level. Westructure our FYS to promote academic confidence and interest in ourdisciplines for the women in MapCores. It covers not only contributionsthat women have made and barriers that women face in thesedisciplines, but also research frontiers and science policy issues inthese disciplines. While the women in MapCores find covering thesetopics beneficial, the most important benefit of the course is the supportive cohort that develops from it

Super-Droplet Method for the Numerical Simulation of Clouds and Precipitation: a Particle-Based Microphysics Model Coupled with Non-hydrostatic Model

A novel simulation model of cloud microphysics is developed, which is named Super-Droplet Method (SDM). SDM enables accurate calculation of cloud microphysics with reasonable cost in computation. A simple SDM for warm rain, which incorporates sedimentation, condensation/evaporation, stochastic coalescence, is developed. The methodology to couple SDM and a non-hydrostatic model is also developed. It is confirmed that the result of our Monte Carlo scheme for the coalescence of super-droplets agrees fairly well with the solution of stochastic coalescence equation. A preliminary simulation of a shallow maritime cumulus formation initiated by a warm bubble is presented to demonstrate the practicality of SDM. Further discussions are devoted for the extension and the computational efficiency of SDM to incorporate various properties of clouds, such as, several types of ice crystals, several sorts of soluble/insoluble CCNs, their chemical reactions, electrification, and the breakup of droplets. It is suggested that the computational cost of SDM becomes lower than spectral (bin) method when the number of attributes $d$ becomes larger than some critical value, which may be $2\sim4$

Tolerance of a standard intact protein formula versus a partially hydrolyzed formula in healthy, term infants

<p>Abstract</p> <p>Background</p> <p>Parents who perceive common infant behaviors as formula intolerance-related often switch formulas without consulting a health professional. Up to one-half of formula-fed infants experience a formula change during the first six months of life.</p> <p>Methods</p> <p>The objective of this study was to assess discontinuance due to study physician-assessed formula intolerance in healthy, term infants. Infants (335) were randomized to receive either a standard intact cow milk protein formula (INTACT) or a partially hydrolyzed cow milk protein formula (PH) in a 60 day non-inferiority trial. Discontinuance due to study physician-assessed formula intolerance was the primary outcome. Secondary outcomes included number of infants who discontinued for any reason, including parent-assessed.</p> <p>Results</p> <p>Formula intolerance between groups (INTACT, 12.3% vs. PH, 13.7%) was similar for infants who completed the study or discontinued due to study physician-assessed formula intolerance. Overall study discontinuance based on parent- vs. study physician-assessed intolerance for all infants (14.4 vs.11.1%) was significantly different (P = 0.001).</p> <p>Conclusion</p> <p>This study demonstrated no difference in infant tolerance of intact vs. partially hydrolyzed cow milk protein formulas for healthy, term infants over a 60-day feeding trial, suggesting nonstandard partially hydrolyzed formulas are not necessary as a first-choice for healthy infants. Parents frequently perceived infant behavior as formula intolerance, paralleling previous reports of unnecessary formula changes.</p> <p>Trial Registration</p> <p>clinicaltrials.gov: NCT00666120</p