4,149 research outputs found
Quasi-two-body decays in the perturbative QCD approach
We study the quasi-two-body decays by employing
the perturbative QCD approach. The two-meson distribution amplitudes
\Phi_{K\pi}^{\text{P-wave}} are adopted to describe the final state
interactions of the kaon-pion pair in the resonance region. The resonance line
shape for the -wave component in the time-like form factor
is parameterized by the relativistic Breit-Wigner function. For
most considered decay modes, the theoretical predictions for their branching
ratios are consistent with currently available experimental measurements within
errors. We also disscuss some ratios of the branching fractions of the
concerned decay processes. More precise data from LHCb and Belle-II are
expected to test our predictions.Comment: 10 pages, 3 figures and 2 tables.To be published in EPJ
The Implication of Climate Signal for Precipitation in the Heihe River Basin, Northwest China
This paper studies the stochastic dynamic variability of precipitation, for the upper, middle, and lower reaches of the Heihe River basin in Northwest China, by employing Mann-Kendall statistic, Pettitt test, and wavelet transform methods. The possible associations with three prominent climatic patterns, El NiΓ±o-Southern Oscillation (ENSO), Artic Oscillation (AO), and Indian Ocean Dipole (IOD), are examined by using multiscale wavelet coherence method. No significant trend is identified for the interannual precipitation variability. However, about 2-year significant variability is detected for the lower reach of the Heihe River basin, and this dominating precipitation variability is essentially depicted by AO. The possible influences of ENSO are exerted on long-term timescale, 8β16 years. The obtained knowledge is helpful for the predications of extreme hydroclimatological events and better reservoir operations for regional water resources
HQDec: Self-Supervised Monocular Depth Estimation Based on a High-Quality Decoder
Decoders play significant roles in recovering scene depths. However, the
decoders used in previous works ignore the propagation of multilevel lossless
fine-grained information, cannot adaptively capture local and global
information in parallel, and cannot perform sufficient global statistical
analyses on the final output disparities. In addition, the process of mapping
from a low-resolution feature space to a high-resolution feature space is a
one-to-many problem that may have multiple solutions. Therefore, the quality of
the recovered depth map is low. To this end, we propose a high-quality decoder
(HQDec), with which multilevel near-lossless fine-grained information, obtained
by the proposed adaptive axial-normalized position-embedded channel attention
sampling module (AdaAxialNPCAS), can be adaptively incorporated into a
low-resolution feature map with high-level semantics utilizing the proposed
adaptive information exchange scheme. In the HQDec, we leverage the proposed
adaptive refinement module (AdaRM) to model the local and global dependencies
between pixels in parallel and utilize the proposed disparity attention module
to model the distribution characteristics of disparity values from a global
perspective. To recover fine-grained high-resolution features with maximal
accuracy, we adaptively fuse the high-frequency information obtained by
constraining the upsampled solution space utilizing the local and global
dependencies between pixels into the high-resolution feature map generated from
the nonlearning method. Extensive experiments demonstrate that each proposed
component improves the quality of the depth estimation results over the
baseline results, and the developed approach achieves state-of-the-art results
on the KITTI and DDAD datasets. The code and models will be publicly available
at \href{https://github.com/fwucas/HQDec}{HQDec}
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