52,195 research outputs found
Probing the excited-state quantum phase transition through statistics of Loschmidt echo and quantum work
By analyzing the probability distributions of the Loschmidt echo (LE) and
quantum work, we examine the nonequilibrium effects of a quantum many-body
system, which exhibits an excited-state quantum phase transition (ESQPT).
We find that depending on the value of the controlling parameter the
distribution of the LE displays different patterns.
At the critical point of the ESQPT, both the averaged LE and the averaged
work show a cusplike shape.
Furthermore, by employing the finite-size scaling analysis of the averaged
work, we obtain the critical exponent of the ESQPT.
Finally, we show that at the critical point of ESQPT the eigenstate is a
highly localized state, further highlighting the influence of the ESQPT on the
properties of the many-body system.Comment: 10 pages, 13 figures; accepted for publication in Physical Review
A Dynamic Epistemic Framework for Conformant Planning
In this paper, we introduce a lightweight dynamic epistemic logical framework
for automated planning under initial uncertainty. We reduce plan verification
and conformant planning to model checking problems of our logic. We show that
the model checking problem of the iteration-free fragment is PSPACE-complete.
By using two non-standard (but equivalent) semantics, we give novel model
checking algorithms to the full language and the iteration-free language.Comment: In Proceedings TARK 2015, arXiv:1606.0729
An Efficient Approach for Polyps Detection in Endoscopic Videos Based on Faster R-CNN
Polyp has long been considered as one of the major etiologies to colorectal
cancer which is a fatal disease around the world, thus early detection and
recognition of polyps plays a crucial role in clinical routines. Accurate
diagnoses of polyps through endoscopes operated by physicians becomes a
challenging task not only due to the varying expertise of physicians, but also
the inherent nature of endoscopic inspections. To facilitate this process,
computer-aid techniques that emphasize fully-conventional image processing and
novel machine learning enhanced approaches have been dedicatedly designed for
polyp detection in endoscopic videos or images. Among all proposed algorithms,
deep learning based methods take the lead in terms of multiple metrics in
evolutions for algorithmic performance. In this work, a highly effective model,
namely the faster region-based convolutional neural network (Faster R-CNN) is
implemented for polyp detection. In comparison with the reported results of the
state-of-the-art approaches on polyps detection, extensive experiments
demonstrate that the Faster R-CNN achieves very competing results, and it is an
efficient approach for clinical practice.Comment: 6 pages, 10 figures,2018 International Conference on Pattern
Recognitio
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