103,571 research outputs found
A New Data Processing Inequality and Its Applications in Distributed Source and Channel Coding
In the distributed coding of correlated sources, the problem of
characterizing the joint probability distribution of a pair of random variables
satisfying an n-letter Markov chain arises. The exact solution of this problem
is intractable. In this paper, we seek a single-letter necessary condition for
this n-letter Markov chain. To this end, we propose a new data processing
inequality on a new measure of correlation by means of spectrum analysis. Based
on this new data processing inequality, we provide a single-letter necessary
condition for the required joint probability distribution. We apply our results
to two specific examples involving the distributed coding of correlated
sources: multi-terminal rate-distortion region and multiple access channel with
correlated sources, and propose new necessary conditions for these two
problems.Comment: 45 pages, 3 figures, submitted to IEEE Trans. Information Theor
Studies of hypersonic viscous flows over a blunt body at low Reynolds number
Viscous hypersonic shock layer over blunt bodies at low Reynolds numbe
Recent trends in particle size analysis techniques
Recent advances and developments in the particle-sizing technologies are briefly reviewed in accordance with three operating principles including particle size and shape descriptions. Significant trends of the particle size analysing equipment recently developed show that compact electronic circuitry and rapid data processing systems were mainly adopted in the instrument design. Some newly developed techniques characterizing the particulate system were also introduced
Enhanced Static Approximation to the Electron Self-Energy Operator for Efficient Calculation of Quasiparticle Energies
An enhanced static approximation for the electron self energy operator is
proposed for efficient calculation of quasiparticle energies. Analysis of the
static COHSEX approximation originally proposed by Hedin shows that most of the
error derives from the short wavelength contributions of the assumed adiabatic
accumulation of the Coulomb-hole. A wavevector dependent correction factor can
be incorporated as the basis for a new static approximation. This factor can be
approximated by a single scaling function, determined from the homogeneous
electron gas model. The local field effect in real materials is captured by a
simple ansatz based on symmetry consideration. As inherited from the COHSEX
approximation, the new approximation presents a Hermitian self-energy operator
and the summation over empty states is eliminated from the evaluation of the
self energy operator. Tests were conducted comparing the new approximation to
GW calculations for diverse materials ranging from crystals and nanotubes. The
accuracy for the minimum gap is about 10% or better. Like in the COHSEX
approximation, the occupied bandwidth is overestimated.Comment: Submitted to Physical Review
Majorana Neutrino Masses and Neutrino Oscillations
We examine some patterns of Majorana neutrino mass matrix which is compatible
with the phenomenological lepton flavor mixing matrix and non-observation of
neutrinoless double beta decay. Imposing for the Majorana
neutrino mass matrix in the leading order, we obtain a relationship between the
solar mixing angle and the neutrino masses and . Additional possible
texture zeros are assigned to the mass matrix so as for the nonvanishing
to be predictable in terms of neutrino masses. We also show how
three neutrino masses can be predicted from the solar mixing angle and the
experimental results of and in this
framework, and we discuss naturality of the forms of the mass matrix found in
our work.Comment: 14 pages, RevTe
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