22,632 research outputs found
The moderate resolution imaging spectrometer: An EOS facility instrument candidate for application of data compression methods
The Moderate Resolution Imaging Spectrometer (MODIS) observing facility will operate on the Earth Observing System (EOS) in the late 1990's. It is estimated that this observing facility will produce over 200 gigabytes of data per day requiring a storage capability of just over 300 gigabytes per day. Archiving, browsing, and distributing the data associated with MODIS represents a rich opportunity for testing and applying both lossless and lossy data compression methods
The Reliability Function of Lossy Source-Channel Coding of Variable-Length Codes with Feedback
We consider transmission of discrete memoryless sources (DMSes) across
discrete memoryless channels (DMCs) using variable-length lossy source-channel
codes with feedback. The reliability function (optimum error exponent) is shown
to be equal to where is the rate-distortion
function of the source, is the maximum relative entropy between output
distributions of the DMC, and is the Shannon capacity of the channel. We
show that, in this setting and in this asymptotic regime, separate
source-channel coding is, in fact, optimal.Comment: Accepted to IEEE Transactions on Information Theory in Apr. 201
Measurement of spectral functions of ultracold atoms in disordered potentials
We report on the measurement of the spectral functions of noninteracting
ultracold atoms in a three-dimensional disordered potential resulting from an
optical speckle field. Varying the disorder strength by 2 orders of magnitude,
we observe the crossover from the "quantum" perturbative regime of low disorder
to the "classical" regime at higher disorder strength, and find an excellent
agreement with numerical simulations. The method relies on the use of
state-dependent disorder and the controlled transfer of atoms to create
well-defined energy states. This opens new avenues for experimental
investigations of three-dimensional Anderson localization
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