29,146 research outputs found
Calculating excited states of molecular aggregates by the renormalized excitonic method
In this paper, we apply the recently developed ab initio renormalized
excitonic method (REM) to the excitation energy calculations of various
molecular aggregates, through the extension of REM to the time-dependent
density functional theory (TDDFT). Tested molecular aggregate systems include
one-dimensional hydrogen-bonded water chains, ring crystals with -
stacking or van-der Waals interactions and the general aqueous systems with
polar and non-polar solutes. The basis set factor as well as the effect of the
exchange-correlation functionals are also investigated. The results indicate
that the REM-TDDFT method with suitable basis set and exchange-correlation
functionals can give good descriptions of excitation energies and excitation
area for lowest electronic excitations in the molecular aggregate systems with
economic computational costs. It's shown that the deviations of REM-TDDFT
excitation energies from those by standard TDDFT are much less than 0.1 eV and
the computational time can be reduced by one order
Constraints on the CKM angle alpha in the B --> rho rho decays
Using a data sample of 122 million Upsilon(4S) -> BBbar decays collected with
BaBar detector at the PEP-II asymmetric B factory at SLAC, we measure the
time-dependent-asymmetry parameters of the longitudinally polarized component
in the B0 -> rho^+ rho^- decay as C_L = -0.23 +/- 0.24 (stat) +/- 0.14 (syst)
and S_L = -0.19 +/- 0.33 (stat) +/- 0.11 (syst). The B0 -> rho0 rho0 decay mode
is also searched for in a data sample of about 227 million BBbar pairs. No
significant signal is observed, and an upper limit of 1.1 * 10-6 (90% C.L.) on
the branching fraction is set. The penguin contribution to the CKM angle
uncertainty is measured to be 11 degree. All results are preliminary.Comment: 3 pages, 1 postscript figues, submitted to DPF200
FSMJ: Feature Selection with Maximum Jensen-Shannon Divergence for Text Categorization
In this paper, we present a new wrapper feature selection approach based on
Jensen-Shannon (JS) divergence, termed feature selection with maximum
JS-divergence (FSMJ), for text categorization. Unlike most existing feature
selection approaches, the proposed FSMJ approach is based on real-valued
features which provide more information for discrimination than binary-valued
features used in conventional approaches. We show that the FSMJ is a greedy
approach and the JS-divergence monotonically increases when more features are
selected. We conduct several experiments on real-life data sets, compared with
the state-of-the-art feature selection approaches for text categorization. The
superior performance of the proposed FSMJ approach demonstrates its
effectiveness and further indicates its wide potential applications on data
mining.Comment: 8 pages, 6 figures, World Congress on Intelligent Control and
Automation, 201
Leveraging Mid-Level Deep Representations For Predicting Face Attributes in the Wild
Predicting facial attributes from faces in the wild is very challenging due
to pose and lighting variations in the real world. The key to this problem is
to build proper feature representations to cope with these unfavourable
conditions. Given the success of Convolutional Neural Network (CNN) in image
classification, the high-level CNN feature, as an intuitive and reasonable
choice, has been widely utilized for this problem. In this paper, however, we
consider the mid-level CNN features as an alternative to the high-level ones
for attribute prediction. This is based on the observation that face attributes
are different: some of them are locally oriented while others are globally
defined. Our investigations reveal that the mid-level deep representations
outperform the prediction accuracy achieved by the (fine-tuned) high-level
abstractions. We empirically demonstrate that the midlevel representations
achieve state-of-the-art prediction performance on CelebA and LFWA datasets.
Our investigations also show that by utilizing the mid-level representations
one can employ a single deep network to achieve both face recognition and
attribute prediction.Comment: In proceedings of 2016 International Conference on Image Processing
(ICIP
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