72,765 research outputs found
Boundary-Layer Similar Solutions for Equilibrium Dissociated Air and Application to the Calculation of Laminar Heat-Transfer Distribution on Blunt Bodies in High-Speed Flow
No abstract availabl
Feature Selection via Coalitional Game Theory
We present and study the contribution-selection algorithm (CSA), a novel algorithm for feature selection. The algorithm is based on the multiperturbation shapley analysis (MSA), a framework that relies on game theory to estimate usefulness. The algorithm iteratively estimates the usefulness of features and selects them accordingly, using either forward selection or backward elimination. It can optimize various performance measures over unseen data such as accuracy, balanced error rate, and area under receiver-operator-characteristic curve. Empirical comparison with several other existing feature selection methods shows that the backward elimination variant of CSA leads to the most accurate classification results on an array of data sets
Progress in Electroweak Baryogenesis
Recent work on generating the excess of matter over antimatter in the early
universe during the electroweak phase transition is reviewed.Comment: 50 pages (figures on request), uses harvmac (table of contents
correct for "l" format), UCSD-93-2,BU-HEP-93-
First Results of the 74 MHz VLA-Pie Town Link. Hercules A at Low Frequencies
We present the results of the first successful observations of the Pie Town
link with the Very Large Array (VLA) at 74 MHz on Hercules A. The improvement
in resolution from 25 arcsec to 10 arcsec resolves the helical- and ring-like
features seen at higher frequencies. We also present new high dynamic range
images of this powerful radio galaxy at 325 MHz. Our low frequency observations
confirm the multiple outburst interpretation of the spectral index differences
at high frequencies. Comparison between our radio and ROSAT X-ray data does not
reveal any association between the X-ray emission from the cluster and the
radio lobes. There are no extra regions of radio emission at 74 MHz.Comment: 9 pages, 7 figures, accepted for publication in MNRA
Development of a phase-change thermal storage system using modified anhydrous sodium hydroxide for solar electric power generation
A thermal storage system for use in solar power electricity generation was investigated analytically and experimentally. The thermal storage medium is principally anhydrous NaOH with 8% NaNO3 and 0.2% MnO2. Heat is charged into storage at 584 K and discharged from storage at 582 K by Therminol-66. Physical and thermophysical properties of the storage medium were measured. A mathematical simulation and computer program describing the operation of the system were developed. A 1/10 scale model of a system capable of storing and delivering 3.1 x 10 to the 6th power kJ of heat was designed, built, and tested. Tests included steady state charging, discharging, idling, and charge-discharge conditions simulating a solar daily cycle. Experimental data and computer-predicted results are correlated. A reference design including cost estimates of the full-size system was developed
Stability of attitude control systems acted upon by random perturbations
Mathematical models on stability of attitude control systems acted upon by random perturbation processe
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