4,296 research outputs found
Hugoniot of shocked liquid deuterium up to 300 GPa: Quantum molecular dynamic simulations
Quantum molecular dynamic (QMD) simulations are introduced to study the
thermophysical properties of liquid deuterium under shock compression. The
principal Hugoniot is determined from the equation of states, where
contributions from molecular dissociation and atomic ionization are also added
onto the QMD data. At pressures below 100 GPa, our results show that the local
maximum compression ratio of 4.5 can be achieved at 40 GPa, which is in good
agreement with magnetically driven flyer and convergent-explosive experiments;
At the pressure between 100 and 300 GPa, the compression ratio reaches a
maximum of 4.95, which agrees well with recent high power laser-driven
experiments. In addition, the nonmetal-metal transition and optical properties
are also discussed.Comment: 4.1 pages, 4 figure
Non-Hyperbolic Right-Angled Coxeter Groups with Menger Curve Boundary
We find a class of simplicial complexes as nerves of non-hyperbolic right-angled Coxetergroups, with boundary homeomorphic to the Menger curve. The nerves are triangulations of compact orientable surfaces with boundary. In particular, the nerves are non-graphs
Twist-3 contributions to processes in perturbative QCD approach
As one of the simplest hadronic processes, () could be a good testing ground for our understanding of
the perturbative and nonperturbative structure of QCD, and will be studied with
high precision at BELLE-\RNum{2} in the near future. In this paper, we revisit
these processes with twist-3 corrections in the perturbative QCD approach based
on the factorization theorem, in which transverse degrees of freedom as
well as resummation effects are taken into account. The influence of the
distribution amplitudes on the cross sections are discussed in detail. Our work
shows that not only the transverse momentum effects but also the twist-3
corrections play a significant role in the processes in the intermediate energy region. Especially in the few GeV
region, the twist-3 contributions become dominant in the cross sections. And it
is noteworthy that both the twist-3 result of the cross
section and that of the cross section agree well with the BELLE
and ALEPH measurements. For the pion and kaon angular distributions, there
still exist discrepancies between our results and the experimental
measurements. Possible reasons for these discrepancies are discussed briefly.Comment: 19 pages, 7 figures and 2 tables. Contents improved and more
discussions adde
EAST: An Efficient and Accurate Scene Text Detector
Previous approaches for scene text detection have already achieved promising
performances across various benchmarks. However, they usually fall short when
dealing with challenging scenarios, even when equipped with deep neural network
models, because the overall performance is determined by the interplay of
multiple stages and components in the pipelines. In this work, we propose a
simple yet powerful pipeline that yields fast and accurate text detection in
natural scenes. The pipeline directly predicts words or text lines of arbitrary
orientations and quadrilateral shapes in full images, eliminating unnecessary
intermediate steps (e.g., candidate aggregation and word partitioning), with a
single neural network. The simplicity of our pipeline allows concentrating
efforts on designing loss functions and neural network architecture.
Experiments on standard datasets including ICDAR 2015, COCO-Text and MSRA-TD500
demonstrate that the proposed algorithm significantly outperforms
state-of-the-art methods in terms of both accuracy and efficiency. On the ICDAR
2015 dataset, the proposed algorithm achieves an F-score of 0.7820 at 13.2fps
at 720p resolution.Comment: Accepted to CVPR 2017, fix equation (3
More Efficient On-the-Fly Verification Methods of Colored Petri Nets
Colored Petri Nets (CP-nets or CPNs) are powerful modeling language for concurrent systems. As for CPNs' model checking, the mainstream method is unfolding that transforms a CPN into an equivalent P/T net. However the equivalent P/T net tends to be too enormous to be handled. As for checking CPN models without unfolding, we present three practical on-the-fly verification methods which are all focused on how to make state space generation more efficient. The first one is a basic one, based on a standard state space generation algorithm, but its efficiency is low. The second one is an overall improvement of the first. The third one sacrifices some applicability for higher efficiency. We implemented the three algorithms and validated great efficiency of latter two algorithms through experimental results
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