133,069 research outputs found
Measuring information growth in fractal phase space
We look at chaotic systems evolving in fractal phase space. The entropy
change in time due to the fractal geometry is assimilated to the information
growth through the scale refinement. Due to the incompleteness, at any scale,
of the information calculation in fractal support, the incomplete normalization
is applied throughout the paper. It is shown that the
information growth is nonadditive and is proportional to the trace-form
so that it can be connected to several nonadditive
entropies. This information growth can be extremized to give, for
non-equilibrium systems, power law distributions of evolving stationary state
which may be called ``maximum entropic evolution''.Comment: 10 pages, 1 eps figure, TeX. Chaos, Solitons & Fractals (2004), in
pres
Determination of anisotropic dipole moments in self-assembled quantum dots using Rabi oscillations
By investigating the polarization-dependent Rabi oscillations using
photoluminescence spectroscopy, we determined the respective transition dipole
moments of the two excited excitonic states |Ex> and |Ey> of a single
self-assembled quantum dot that are nondegenerate due to shape anisotropy. We
find that the ratio of the two dipole moments is close to the physical
elongation ratio of the quantum dot.Comment: 11 pages, 2 figures, MS Word generated PDF fil
Maximum Path Information and Fokker-Planck Equation
We present in this paper a rigorous method to derive the nonlinear
Fokker-Planck (FP) equation of anomalous diffusion directly from a
generalization of the principle of least action of Maupertuis proposed by Wang
for smooth or quasi-smooth irregular dynamics evolving in Markovian process.
The FP equation obtained may take two different but equivalent forms. It was
also found that the diffusion constant may depend on both q (the index of
Tsallis entropy) and the time t.Comment: 7 page
Pressure induced Raman and fluorescence singularities in
The pressure effect on the fluoride scheelite laser host is studied
at room temperature up to 26 GPa by Raman scattering and up to 40 GPa by
fluorescence of doped sample. The Raman spectra exhibit three
singularities at the vicinity of 6 GPa, 10-12 GPa and 16-17 GPa. The samples
pressurized to 21 GPa or higher do not recover the original phase after being
released, giving more Raman lines than original samples. The luminescence
spectra of are collected in the energy range corresponding to
following transitions , and
. Singularities are observed in the vicinity of 6 GPa, 10 GPa, 16
GPa, 23 GPa in agreement with the Raman study. Moreover, an irreversible
transition occurs at 23 GPa. The samples pressurized to above 26 GPa become
amorphous when released and all the sharp lines disappear. Above 31 GPa, the
spectra at high pressures show only some broad bands corresponding to
transitions between two multiplets of the configuration of .
These singularities suggest possible phase transformations leading to lowering
of the lattice symmetry.Comment: 12 pages, 13 figures, 2 table, LaTe
Symbol error rate analysis for M-QAM modulated physical-layer network coding with phase errors
Recent theoretical studies of physical-layer network coding (PNC) show much interest on high-level modulation, such as M-ary quadrature amplitude modulation (M-QAM), and most related works are based on the assumption of phase synchrony. The possible presence of synchronization error and channel estimation error highlight the demand of analyzing the symbol error rate (SER) performance of PNC under different phase errors. Assuming synchronization and a general constellation mapping method, which maps the superposed signal into a set of M coded symbols, in this paper, we analytically derive the SER for M-QAM modulated PNC under different phase errors. We obtain an approximation of SER for general M-QAM modulations, as well as exact SER for quadrature phase-shift keying (QPSK), i.e. 4-QAM. Afterwards, theoretical results are verified by Monte Carlo simulations. The results in this paper can be used as benchmarks for designing practical systems supporting PNC. © 2012 IEEE
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