759 research outputs found
Chiral Analysis of the Nucleon Mass and Sigma Commutator
Methods for describing the light quark mass dependence of the nucleon mass
calculated in lattice QCD are compared. All preserve the leading and
next-to-leading non-analytic behavior of QCD. It is found that the low-energy
coefficients describing the mass in the SU(2) limit and the slope in pion mass
squared are independent of the method used. Results for the masses of the other
members of the baryon octet are also presented. Finally, results are presented
for the pion-nucleon sigma commutator, based upon recent data from the CLS
Collaboratio
Kerr-Sen Black Hole as Accelerator for Spinning Particles
It has been proved that arbitrarily high-energy collision between two
particles can occur near the horizon of an extremal Kerr black hole as long as
the energy and angular momentum of one particle satisfies a critical
relation, which is called the BSW mechanism. Previous researchers mainly
concentrate on geodesic motion of particles. In this paper, we will take
spinning particle which won't move along a timelike geodesic into our
consideration, hence, another parameter describing the particle's spin
angular momentum was introduced. By employing the Mathisson-Papapetrou-Dixon
equation describing the movement of spinning particle, we will explore whether
a Kerr-Sen black hole which is slightly different from Kerr black hole can be
used to accelerate a spinning particle to arbitrarily high energy. We found
that when one of the two colliding particles satisfies a critical relation
between the energy and the total angular momentum , or has a critical
spinning angular momentum , a divergence of the center-of-mass energy
will be obtained.Comment: Latex,17 pages,1 figure,minor revision,accepted by PR
ToonTalker: Cross-Domain Face Reenactment
We target cross-domain face reenactment in this paper, i.e., driving a
cartoon image with the video of a real person and vice versa. Recently, many
works have focused on one-shot talking face generation to drive a portrait with
a real video, i.e., within-domain reenactment. Straightforwardly applying those
methods to cross-domain animation will cause inaccurate expression transfer,
blur effects, and even apparent artifacts due to the domain shift between
cartoon and real faces. Only a few works attempt to settle cross-domain face
reenactment. The most related work AnimeCeleb requires constructing a dataset
with pose vector and cartoon image pairs by animating 3D characters, which
makes it inapplicable anymore if no paired data is available. In this paper, we
propose a novel method for cross-domain reenactment without paired data.
Specifically, we propose a transformer-based framework to align the motions
from different domains into a common latent space where motion transfer is
conducted via latent code addition. Two domain-specific motion encoders and two
learnable motion base memories are used to capture domain properties. A source
query transformer and a driving one are exploited to project domain-specific
motion to the canonical space. The edited motion is projected back to the
domain of the source with a transformer. Moreover, since no paired data is
provided, we propose a novel cross-domain training scheme using data from two
domains with the designed analogy constraint. Besides, we contribute a cartoon
dataset in Disney style. Extensive evaluations demonstrate the superiority of
our method over competing methods
A Dispersive Analysis on the and Resonances in Processes
We estimate the di-photon coupling of , and
resonances in a coupled channel dispersive approach. The di-photon
coupling is also reinvestigated using a single channel matrix for
scattering with better analyticity property, and it is found to be
significantly smaller than that of a state. Especially we also
estimate the di-photon coupling of the third sheet pole located near
threshold, denoted as .
It is argued that this third sheet pole may be originated from a coupled
channel Breit-Wigner description of the resonance.Comment: 24 pages and 13 eps figures. A nuerical bug in previous version is
fixed. Some results changed. References and new figures added. Version to
appear in Phys. Rev.
Trigger efficiencies at BES III
Trigger efficiencies at BES III were determined for both the J/psi and psi'
data taking of 2009. Both dedicated runs and physics datasets are used;
efficiencies are presented for Bhabha-scattering events, generic hadronic decay
events involving charged tracks, dimuon events and psi' -> pi+pi-J/psi, J/psi
-> l+l- events (l an electron or muon). The efficiencies are found to lie well
above 99% for all relevant physics cases, thus fulfilling the BES III design
specifications.Comment: 6 pages, 4 figure
Motif-guided sparse decomposition of gene expression data for regulatory module identification
<p>Abstract</p> <p>Background</p> <p>Genes work coordinately as gene modules or gene networks. Various computational approaches have been proposed to find gene modules based on gene expression data; for example, gene clustering is a popular method for grouping genes with similar gene expression patterns. However, traditional gene clustering often yields unsatisfactory results for regulatory module identification because the resulting gene clusters are co-expressed but not necessarily co-regulated.</p> <p>Results</p> <p>We propose a novel approach, motif-guided sparse decomposition (mSD), to identify gene regulatory modules by integrating gene expression data and DNA sequence motif information. The mSD approach is implemented as a two-step algorithm comprising estimates of (1) transcription factor activity and (2) the strength of the predicted gene regulation event(s). Specifically, a motif-guided clustering method is first developed to estimate the transcription factor activity of a gene module; sparse component analysis is then applied to estimate the regulation strength, and so predict the target genes of the transcription factors. The mSD approach was first tested for its improved performance in finding regulatory modules using simulated and real yeast data, revealing functionally distinct gene modules enriched with biologically validated transcription factors. We then demonstrated the efficacy of the mSD approach on breast cancer cell line data and uncovered several important gene regulatory modules related to endocrine therapy of breast cancer.</p> <p>Conclusion</p> <p>We have developed a new integrated strategy, namely motif-guided sparse decomposition (mSD) of gene expression data, for regulatory module identification. The mSD method features a novel motif-guided clustering method for transcription factor activity estimation by finding a balance between co-regulation and co-expression. The mSD method further utilizes a sparse decomposition method for regulation strength estimation. The experimental results show that such a motif-guided strategy can provide context-specific regulatory modules in both yeast and breast cancer studies.</p
3D GAN Inversion with Facial Symmetry Prior
Recently, a surge of high-quality 3D-aware GANs have been proposed, which
leverage the generative power of neural rendering. It is natural to associate
3D GANs with GAN inversion methods to project a real image into the generator's
latent space, allowing free-view consistent synthesis and editing, referred as
3D GAN inversion. Although with the facial prior preserved in pre-trained 3D
GANs, reconstructing a 3D portrait with only one monocular image is still an
ill-pose problem. The straightforward application of 2D GAN inversion methods
focuses on texture similarity only while ignoring the correctness of 3D
geometry shapes. It may raise geometry collapse effects, especially when
reconstructing a side face under an extreme pose. Besides, the synthetic
results in novel views are prone to be blurry. In this work, we propose a novel
method to promote 3D GAN inversion by introducing facial symmetry prior. We
design a pipeline and constraints to make full use of the pseudo auxiliary view
obtained via image flipping, which helps obtain a robust and reasonable
geometry shape during the inversion process. To enhance texture fidelity in
unobserved viewpoints, pseudo labels from depth-guided 3D warping can provide
extra supervision. We design constraints aimed at filtering out conflict areas
for optimization in asymmetric situations. Comprehensive quantitative and
qualitative evaluations on image reconstruction and editing demonstrate the
superiority of our method.Comment: Project Page is at https://feiiyin.github.io/SPI
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