9,217 research outputs found
A Novel Self-Intersection Penalty Term for Statistical Body Shape Models and Its Applications in 3D Pose Estimation
Statistical body shape models are widely used in 3D pose estimation due to
their low-dimensional parameters representation. However, it is difficult to
avoid self-intersection between body parts accurately. Motivated by this fact,
we proposed a novel self-intersection penalty term for statistical body shape
models applied in 3D pose estimation. To avoid the trouble of computing
self-intersection for complex surfaces like the body meshes, the gradient of
our proposed self-intersection penalty term is manually derived from the
perspective of geometry. First, the self-intersection penalty term is defined
as the volume of the self-intersection region. To calculate the partial
derivatives with respect to the coordinates of the vertices, we employed
detection rays to divide vertices of statistical body shape models into
different groups depending on whether the vertex is in the region of
self-intersection. Second, the partial derivatives could be easily derived by
the normal vectors of neighboring triangles of the vertices. Finally, this
penalty term could be applied in gradient-based optimization algorithms to
remove the self-intersection of triangular meshes without using any
approximation. Qualitative and quantitative evaluations were conducted to
demonstrate the effectiveness and generality of our proposed method compared
with previous approaches. The experimental results show that our proposed
penalty term can avoid self-intersection to exclude unreasonable predictions
and improves the accuracy of 3D pose estimation indirectly. Further more, the
proposed method could be employed universally in triangular mesh based 3D
reconstruction
Quantum Decoherence with Holography
Quantum decoherence is the loss of a system's purity due to its interaction
with the surrounding environment. Via the AdS/CFT correspondence, we study how
a system decoheres when its environment is a strongly-coupled theory. In the
Feynman-Vernon formalism, we compute the influence functional holographically
by relating it to the generating function of Schwinger-Keldysh propagators and
thereby obtain the dynamics of the system's density matrix.
We present two exactly solvable examples: (1) a straight string in a BTZ
black hole and (2) a scalar probe in AdS. We prepare an initial state that
mimics Schr\"odinger's cat and identify different stages of its decoherence
process using the time-scaling behaviors of R\'enyi entropy. We also relate
decoherence to local quantum quenches, and by comparing the time evolution
behaviors of the Wigner function and R\'enyi entropy we demonstrate that the
relaxation of local quantum excitations leads to the collapse of its
wave-function.Comment: 55 pages, 13 figures; v2 47 pages & 13 figs, minor revision to match
published versio
Electron Flavored Dark Matter
In this paper we investigate the phenomenology of the electron flavored Dirac
dark matter with two types of portal interactions. We analyze constraints from
the electron magnetic moment anomaly, LHC searches of singly charged scalar,
dark matter relic abundance as well as direct and indirect detections. Our
study shows that the available parameter space is quite constrained, but there
are parameter space that is compatible with the current data. We further show
that the DAMPE cosmic ray electron excess, which indicates cosmic ray excess at
around 1.5 TeV, can be interpreted as the annihilation of dark matter into
electron positron pairs in this model.Comment: 6 pages, 5 figure
Magnetic moments of the spin- doubly heavy baryons
In this work, we investigate the chiral corrections to the magnetic moments
of the spin- doubly charmed baryons systematically up to
next-to-next-to-leading order with the heavy baryon chiral perturbation theory.
The numerical results are given up to next-to-leading order:
, ,
. As a by-product, we have also calculated
the magnetic moments of the spin- doubly bottom baryons and charmed
bottom baryons:
, ,
, ,
, .Comment: 10 pages,2 figures. arXiv admin note: text overlap with
arXiv:1707.02765. Replace the published versio
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