133,490 research outputs found
Medical vest broadens treatment capability
Universal sized vest, with specially tailored pockets designed to hold medical supplies, provides first aid/first care medical teams with broadened on-site capability. Vest is made of nylon, tough fibrous materials, and polyvinyl chloride. Design facilitates rapid donning, doffing, and adjustment
Shuttle program. Solar activity prediction of sunspot numbers, predicted solar radio flux
A solar activity prediction technique for monthly mean sunspot numbers over a period of approximately ten years from February 1979 to January 1989 is presented. This includes the predicted maximum epoch of solar cycle 21, approximately January 1980, and the predicted minimum epoch of solar cycle 22, approximately March 1987. Additionally, the solar radio flux 10.7 centimeter smooth values are included for the same time frame using a smooth 13 month empirical relationship. The incentive for predicting solar activity values is the requirement of solar flux data as input to upper atmosphere density models utilized in mission planning satellite orbital lifetime studies
âTwo Wars and the Long Twentieth Century:â A Response
Drew Gilpin Faust, president of Harvard University and renowned historian of the American Civil War, authored an article in the New Yorker recently entitled âTwo Wars and the Long Twentieth Century.â Taken primarily from her remarks in the Rede Lecture delivered at the University of Cambridge earlier in 2015, Faustâs article takes advantage of the proximity of the anniversaries of the First World War and the American Civil War to advocate for a dialogue of greater continuity between the two conflicts. [excerpt
Haldane fractional statistics in the fractional quantum Hall effect
We have tested Haldane's ``fractional-Pauli-principle'' description of
excitations around the state in the FQHE, using exact results for
small systems of electrons. We find that Haldane's prediction
for quasiholes and quasiparticles, respectively, describes our results well
with the modification rather than . We also find
that this approach enables us to better understand the {\it energetics\/} of
the ``daughter'' states; in particular, we find good evidence, in terms of the
effective interaction between quasiparticles, that the states and
4/13 should not be stable.Comment: 9 pages, 3 Postscript figures, RevTex 3.0. (UCF-CM-93-005
Testing equality of variances in the analysis of repeated measurements
The problem of comparing the precisions of two instruments using repeated measurements can be cast as an extension of the Pitman-Morgan problem of testing equality of variances of a bivariate normal distribution. Hawkins (1981) decomposes the hypothesis of equal variances in this model into two subhypotheses for which simple tests exist. For the overall hypothesis he proposes to combine the tests of the subhypotheses using Fisher's method and empirically compares the component tests and their combination with the likelihood ratio test. In this paper an attempt is made to resolve some discrepancies and puzzling conclusions in Hawkins's study and to propose simple modifications.\ud
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The new tests are compared to the tests discussed by Hawkins and to each other both in terms of the finite sample power (estimated by Monte Carlo simulation) and theoretically in terms of asymptotic relative efficiencies
Quantitative analysis of aircraft multispectral-scanner data and mapping of water-quality parameters in the James River in Virginia
Statistical analysis techniques were applied to develop quantitative relationships between in situ river measurements and the remotely sensed data that were obtained over the James River in Virginia on 28 May 1974. The remotely sensed data were collected with a multispectral scanner and with photographs taken from an aircraft platform. Concentration differences among water quality parameters such as suspended sediment, chlorophyll a, and nutrients indicated significant spectral variations. Calibrated equations from the multiple regression analysis were used to develop maps that indicated the quantitative distributions of water quality parameters and the dispersion characteristics of a pollutant plume entering the turbid river system. Results from further analyses that use only three preselected multispectral scanner bands of data indicated that regression coefficients and standard errors of estimate were not appreciably degraded compared with results from the 10-band analysis
VALUE-ADDED ACTIVITIES AS A RURAL DEVELOPMENT STRATEGY
Community/Rural/Urban Development,
Multipolar theory of black-body radiation shift of atomic energy levels and its implications for optical lattice clocks
A black-body radiation (BBR) shifts of (nsnp ^3P_0) - (ns^2 ^1S_0) clock
transition in divalent atoms Mg, Ca, Sr, and Yb are evaluated. A theory of
multipolar BBR shifts is developed and its implications are discussed. At room
temperatures, the resulting uncertainties in the BBR shifts are relatively
large and substantially affect the projected 10^{-18} fractional accuracy of
the optical-lattice-based clocks.Comment: 4 pages, 1 figure, submitted to Physical Review Letter
SATMC: Spectral Energy Distribution Analysis Through Markov Chains
We present the general purpose spectral energy distribution (SED) fitting
tool SED Analysis Through Markov Chains (SATMC). Utilizing Monte Carlo Markov
Chain (MCMC) algorithms, SATMC fits an observed SED to SED templates or models
of the user's choice to infer intrinsic parameters, generate confidence levels
and produce the posterior parameter distribution. Here we describe the key
features of SATMC from the underlying MCMC engine to specific features for
handling SED fitting. We detail several test cases of SATMC, comparing results
obtained to traditional least-squares methods, which highlight its accuracy,
robustness and wide range of possible applications. We also present a sample of
submillimetre galaxies that have been fitted using the SED synthesis routine
GRASIL as input. In general, these SMGs are shown to occupy a large volume of
parameter space, particularly in regards to their star formation rates which
range from ~30-3000 M_sun yr^-1 and stellar masses which range from
~10^10-10^12 M_sun. Taking advantage of the Bayesian formalism inherent to
SATMC, we also show how the fitting results may change under different
parametrizations (i.e., different initial mass functions) and through
additional or improved photometry, the latter being crucial to the study of
high-redshift galaxies.Comment: 17 pages, 11 figures, MNRAS accepte
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