48,447 research outputs found
Single Image Super-Resolution Using Multi-Scale Convolutional Neural Network
Methods based on convolutional neural network (CNN) have demonstrated
tremendous improvements on single image super-resolution. However, the previous
methods mainly restore images from one single area in the low resolution (LR)
input, which limits the flexibility of models to infer various scales of
details for high resolution (HR) output. Moreover, most of them train a
specific model for each up-scale factor. In this paper, we propose a
multi-scale super resolution (MSSR) network. Our network consists of
multi-scale paths to make the HR inference, which can learn to synthesize
features from different scales. This property helps reconstruct various kinds
of regions in HR images. In addition, only one single model is needed for
multiple up-scale factors, which is more efficient without loss of restoration
quality. Experiments on four public datasets demonstrate that the proposed
method achieved state-of-the-art performance with fast speed
Effects of a mixed vector-scalar kink-like potential for spinless particles in two-dimensional spacetime
The intrinsically relativistic problem of spinless particles subject to a
general mixing of vector and scalar kink-like potentials () is investigated. The problem is mapped into the exactly solvable
Surm-Liouville problem with the Rosen-Morse potential and exact bounded
solutions for particles and antiparticles are found. The behaviour of the
spectrum is discussed in some detail. An apparent paradox concerning the
uncertainty principle is solved by recurring to the concept of effective
Compton wavelength.Comment: 13 pages, 4 figure
Heating of ions by low-frequency Alfv\'{e}n waves in partially ionized plasmas
In the solar atmosphere, the chromospheric and coronal plasmas are much
hotter than the visible photosphere. The heating of the solar atmosphere,
including the partially ionized chromosphere and corona, remains largely
unknown. In this paper we demonstrate that the ions can be substantially heated
by Alfv\'{e}n waves with very low frequencies in partially ionized low beta
plasmas. This differs from other Alfv\'{e}n wave related heating mechanisms
such as ion-neutral collisional damping of Alfv\'{e}n waves and heating
described by previous work on resonant Alfv\'{e}n wave heating. In this paper,
we find that the non-resonant Alfv\'{e}n wave heating is less efficient in
partially ionized plasmas than when there are no ion-neutral collisions, and
the heating efficiency depends on the ratio of the ion-neutral collision
frequency to the ion gyrofrequency.Comment: Published as Letter
Computational Sociolinguistics: A Survey
Language is a social phenomenon and variation is inherent to its social
nature. Recently, there has been a surge of interest within the computational
linguistics (CL) community in the social dimension of language. In this article
we present a survey of the emerging field of "Computational Sociolinguistics"
that reflects this increased interest. We aim to provide a comprehensive
overview of CL research on sociolinguistic themes, featuring topics such as the
relation between language and social identity, language use in social
interaction and multilingual communication. Moreover, we demonstrate the
potential for synergy between the research communities involved, by showing how
the large-scale data-driven methods that are widely used in CL can complement
existing sociolinguistic studies, and how sociolinguistics can inform and
challenge the methods and assumptions employed in CL studies. We hope to convey
the possible benefits of a closer collaboration between the two communities and
conclude with a discussion of open challenges.Comment: To appear in Computational Linguistics. Accepted for publication:
18th February, 201
Aspects of Warped AdS/CFT Correspondence
In this paper we apply the thermodynamics method to investigate the
holographic pictures for the BTZ black hole, the spacelike and the null warped
black holes in three-dimensional topologically massive gravity (TMG) and new
massive gravity (NMG). Even though there are higher derivative terms in these
theories, the thermodynamics method is still effective. It gives consistent
results with the ones obtained by using asymptotical symmetry group (ASG)
analysis. In doing the ASG analysis we develop a brute-force realization of the
Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to
calculate the masses and the angular momenta of the black holes. In particular,
we propose the warped AdS/CFT correspondence in the new massive
gravity, which states that quantum gravity in the warped spacetime could
holographically dual to a two-dimensional CFT with
c_R=c_L=\f{24}{Gm\b^2\sr{2(21-4\b^2)}}.Comment: 22 pages, references added, published version, link of Mathematica
code changed to https://s.yunio.com/Mtus0z or http://pan.baidu.com/s/1mToF
Higgs phenomenology of supersymmetric economical 3-3-1 model
We explore the Higgs sector in the supersymmetric economical 3-3-1 model and
find new features in this sector. The charged Higgs sector is revised i.e., in
difference of the previous work, the exact eigenvalues and states are obtained
without any approximation. In this model, there are three Higgs bosons having
masses equal to that of the gauge bosons--the W and extra X and Y. There is one
scalar boson with mass of 91.4 GeV, which is closed to the boson mass and
in good agreement with present limit: 89.8 GeV at 95% CL. The condition of
eliminating for charged scalar tachyon leads to splitting of VEV at the first
symmetry breaking, namely, . The interactions among the
standard model gauge bosons and scalar fields in the framework of the
supersymmetric economical 3-3-1 model are presented. From these couplings, at
some limit, almost scalar Higgs fields can be recognized in accordance with the
standard model. The hadronic cross section for production of the bilepton
charged Higgs boson at the CERN LHC in the effective vector boson approximation
is calculated. Numerical evaluation shows that the cross section can exceed
35.8 fb.Comment: 33 pages, 1 figur
Modular Invariance for Twisted Modules over a Vertex Operator Superalgebra
The purpose of this paper is to generalize Zhu's theorem about characters of
modules over a vertex operator algebra graded by integer conformal weights, to
the setting of a vertex operator superalgebra graded by rational conformal
weights. To recover SL_2(Z)-invariance of the characters it turns out to be
necessary to consider twisted modules alongside ordinary ones. It also turns
out to be necessary, in describing the space of conformal blocks in the
supersymmetric case, to include certain `odd traces' on modules alongside
traces and supertraces. We prove that the set of supertrace functions, thus
supplemented, spans a finite dimensional SL_2(Z)-invariant space. We close the
paper with several examples.Comment: 42 pages. Published versio
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