50,840 research outputs found
Corrections to Chiral Dynamics of Heavy Hadrons: SU(3) Symmetry Breaking, (with some minor corrections)
In previous publications we have analyzed the strong and electromagnetic
decays of heavy mesons and heavy baryons in a formalism which incorporates
heavy-quark and chiral symmetries. There are two possible symmetry-breaking
effects on the chiral dynamics of heavy hadrons: the finite-mass effects from
light quarks and the corrections from heavy quarks. In the present
paper, chiral-symmetry-breaking effects are studied and applications to various
strong and radiative decays of heavy hadrons are illustrated. SU(3) violations
induced by chiral loops in the radiative decays of charmed mesons and charmed
baryons are compared with those predicted by the constituent quark model. In
particular, available data for decays favor values of the parameters in
chiral perturbation theory which give predictions for decays close to the
quark model results except for the . Implications are discussed.Comment: PHYZZX, 56 pages and 8 figures (available upon request), CLNS
93/1189, IP-ASTP-01-9
Accelerated Training for Massive Classification via Dynamic Class Selection
Massive classification, a classification task defined over a vast number of
classes (hundreds of thousands or even millions), has become an essential part
of many real-world systems, such as face recognition. Existing methods,
including the deep networks that achieved remarkable success in recent years,
were mostly devised for problems with a moderate number of classes. They would
meet with substantial difficulties, e.g. excessive memory demand and
computational cost, when applied to massive problems. We present a new method
to tackle this problem. This method can efficiently and accurately identify a
small number of "active classes" for each mini-batch, based on a set of dynamic
class hierarchies constructed on the fly. We also develop an adaptive
allocation scheme thereon, which leads to a better tradeoff between performance
and cost. On several large-scale benchmarks, our method significantly reduces
the training cost and memory demand, while maintaining competitive performance.Comment: 8 pages, 6 figures, AAAI 201
Person Re-identification with Correspondence Structure Learning
This paper addresses the problem of handling spatial misalignments due to
camera-view changes or human-pose variations in person re-identification. We
first introduce a boosting-based approach to learn a correspondence structure
which indicates the patch-wise matching probabilities between images from a
target camera pair. The learned correspondence structure can not only capture
the spatial correspondence pattern between cameras but also handle the
viewpoint or human-pose variation in individual images. We further introduce a
global-based matching process. It integrates a global matching constraint over
the learned correspondence structure to exclude cross-view misalignments during
the image patch matching process, hence achieving a more reliable matching
score between images. Experimental results on various datasets demonstrate the
effectiveness of our approach
The study of neutron spectra in water bath from Pb target irradiated by 250MeV/u protons
The spallation neutrons were produced by the irradiation of Pb with 250 MeV
protons. The Pb target was surrounded by water which was used to slow down the
emitted neutrons. The moderated neutrons in the water bath were measured by
using the resonance detectors of Au, Mn and In with Cd cover. According to the
measured activities of the foils, the neutron flux at different resonance
energy were deduced and the epithermal neutron spectra were proposed.
Corresponding results calculated with the Monte Carlo code MCNPX were compared
with the experimental data to check the validity of the code.Comment: 6 pages,9 figure
- …
