3,210 research outputs found
Frequency correlations in reflection from random media
We present a theoretical study of frequency correlations of light
backscattered from a random scattering medium. This statistical quantity
provides insight into the dynamics of multiple scattering processes accessible
both, in theoretical and experimental investigations. For frequency
correlations between field amplitudes, we derive a simple expression in terms
of the path length distribution of the underlying backscattering processes. In
a second step, we apply this relation to describe frequency correlations
between intensities in the regime of weak disorder. Since, with increasing
disorder strength, an unexplained breakdown of the angular structure of the
frequency correlation function has recently been reported in experimental
studies, we explore extensions of our model to the regime of stronger disorder.
In particular, we show that closed scattering trajectories tend to suppress the
angular dependence of the frequency correlation function.Comment: 10 pages, 8 figure
Double scattering of intense laser light by two atoms
This paper analyzes coherent backscattering of intense laser light by two
randomly placed distant atoms. Starting from the general two-atom master
equation, we analytically derive the elastic and inelastic background and
interference components of the double scattering spectrum. By expressing the
final results in terms of single-atom observables, the two-atom problem is
shown to be equivalent to a description in terms of single atoms under
bichromatic driving.Comment: 15 pages, 3 figure
Electronic collaboration: Some effects of telecommunication media and machine intelligence on team performance
Both NASA and DoD have had a long standing interest in teamwork, distributed decision making, and automation. While research on these topics has been pursued independently, it is becoming increasingly clear that the integration of social, cognitive, and human factors engineering principles will be necessary to meet the challenges of highly sophisticated scientific and military programs of the future. Images of human/intelligent-machine electronic collaboration were drawn from NASA and Air Force reports as well as from other sources. Here, areas of common concern are highlighted. A description of the author's research program testing a 'psychological distancing' model of electronic media effects and human/expert system collaboration is given
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