11,080 research outputs found
The Lower The Simpler: Simplifying Hierarchical Recurrent Models
To improve the training efficiency of hierarchical recurrent models without
compromising their performance, we propose a strategy named as `the lower the
simpler', which is to simplify the baseline models by making the lower layers
simpler than the upper layers. We carry out this strategy to simplify two
typical hierarchical recurrent models, namely Hierarchical Recurrent
Encoder-Decoder (HRED) and R-NET, whose basic building block is GRU.
Specifically, we propose Scalar Gated Unit (SGU), which is a simplified variant
of GRU, and use it to replace the GRUs at the middle layers of HRED and R-NET.
Besides, we also use Fixed-size Ordinally-Forgetting Encoding (FOFE), which is
an efficient encoding method without any trainable parameter, to replace the
GRUs at the bottom layers of HRED and R-NET. The experimental results show that
the simplified HRED and the simplified R-NET contain significantly less
trainable parameters, consume significantly less training time, and achieve
slightly better performance than their baseline models.Comment: NAACL-HLT 201
Explicit Utilization of General Knowledge in Machine Reading Comprehension
To bridge the gap between Machine Reading Comprehension (MRC) models and
human beings, which is mainly reflected in the hunger for data and the
robustness to noise, in this paper, we explore how to integrate the neural
networks of MRC models with the general knowledge of human beings. On the one
hand, we propose a data enrichment method, which uses WordNet to extract
inter-word semantic connections as general knowledge from each given
passage-question pair. On the other hand, we propose an end-to-end MRC model
named as Knowledge Aided Reader (KAR), which explicitly uses the above
extracted general knowledge to assist its attention mechanisms. Based on the
data enrichment method, KAR is comparable in performance with the
state-of-the-art MRC models, and significantly more robust to noise than them.
When only a subset (20%-80%) of the training examples are available, KAR
outperforms the state-of-the-art MRC models by a large margin, and is still
reasonably robust to noise.Comment: ACL 201
The Strong Decays of Orbitally Excited Mesons by Improved Bethe-Salpeter Method
We calculate the masses and the strong decays of orbitally excited states
, , and by the improved Bethe-Salpeter
method. The predicted masses of and are
, . We
calculate the isospin symmetry violating decay processes
and through mixing and get small widths.
Considering the uncertainties of the masses, for and , we
also calculate the OZI allowed decay channels: and
. For and , the OZI allowed decay
channels , and are studied. In all the decay channels, the reduction formula, PCAC relation
and low energy theorem are used to estimate the decay widths. We also obtain
the strong coupling constants , ,
, , ,
, , ,
and .Comment: 21 pages, 1 figure, 4 table
Deep Learning for Object Saliency Detection and Image Segmentation
In this paper, we propose several novel deep learning methods for object
saliency detection based on the powerful convolutional neural networks. In our
approach, we use a gradient descent method to iteratively modify an input image
based on the pixel-wise gradients to reduce a cost function measuring the
class-specific objectness of the image. The pixel-wise gradients can be
efficiently computed using the back-propagation algorithm. The discrepancy
between the modified image and the original one may be used as a saliency map
for the image. Moreover, we have further proposed several new training methods
to learn saliency-specific convolutional nets for object saliency detection, in
order to leverage the available pixel-wise segmentation information. Our
methods are extremely computationally efficient (processing 20-40 images per
second in one GPU). In this work, we use the computed saliency maps for image
segmentation. Experimental results on two benchmark tasks, namely Microsoft
COCO and Pascal VOC 2012, have shown that our proposed methods can generate
high-quality salience maps, clearly outperforming many existing methods. In
particular, our approaches excel in handling many difficult images, which
contain complex background, highly-variable salient objects, multiple objects,
and/or very small salient objects.Comment: 9 pages, 126 figures, technical repor
The uniform local asymptotics of the total net loss process in a new time-dependent bidimensional renewal model
In this paper, we consider a bidimensional renewal risk model with constant
force of interest, in which the claim size vector with certain local
subexponential marginal distribution and its inter-arrival time are subject to
a new time-dependence structure. We obtain the uniform local asymptotics of the
total net loss process in the model. Moreover, some specific examples of the
joint distribution satisfying the conditions of the dependence structure are
given. Finally, in order to illustrate a condition of the above result, a local
subexponential distribution is find for the first time that, its local
distribution is not almost decreased.Comment: 26 page
Derivation of the gap and Bethe-Salpeter equations at large limit and symmetry preserving truncations
We develop a framework for deriving Dyson-Schwinger Equations (DSEs) and
Bethe-Salpeter Equation (BSE) in QCD at large limit. The starting point
is a modified form (with auxiliary fields) of QCD generating functional. This
framework provides a natural order-by-order truncation scheme for DSEs and BSE,
and the kernels of the equations up to any order are explicitly given. Chiral
symmetry (at chiral limit) is preserved in any order truncation, so it
exemplifies the symmetry preserving truncation scheme. It provides a method to
study DSEs and BSE beyond the Rainbow-Ladder truncation, and is especially
useful to study contributions from non-Abelian dynamics (those arise from gluon
self-interactions). We also derive the equation for the quark-ghost scattering
kernel, and discuss the Slavnov-Taylor identity connecting the quark-gluon
vertex, the quark propagator and the quark-ghost scattering kernel.Comment: 19 pages, 2 figure
On the values of representation functions II
For a set of nonnegative integers, let and denote
the number of solutions to with , and ,
respectively. In this paper, we prove that, if and
is a positive integer such that for all
, then for any with , the set of integers with
has density one. The similar result holds for . These improve the
results of the first author.Comment: 12 page
The Production of and in decays
Considering and as and , we
study the productions of and in exclusive weak decays of
meson by the improved Bethe-Salpeter(B-S) Method. Using the relativistic
B-S equation and Mandelstam formalism, we calculate the corresponding decay
form factors. The predictions of the corresponding branching ratios are:
and . That will provide us a new way to observe
the and in the future, as well as to improve the knowledge
of meson decay.Comment: 15 pages, 7 figure
The weak decay to and by Bethe-Salpeter method
Considering and as and
states, the semileptonic and nonleptonic of decays to and
are studied by the improved Bethe-Salpeter(B-S) Method. The form
factors of decay are calculated through the overlap integrals of the meson wave
functions in the whole accessible kinematical range. The influence of
relativistic corrections are considered in the exclusive decays. Branching
ratios of weak decays to and are predicted. Some of
the branching ratios are: and . These results may
provide useful information to discover and and the
necessary information for the phenomenological study of physics.Comment: arXiv admin note: substantial text overlap with arXiv:1605.0909
Highly birefringent polymer terahertz fiber with honeycomb cladding
Two highly birefringent polymer terahertz (THz) fibers were proposed in this
paper, which were formed with honeycomb cladding and some elliptical air holes
in the fiber core. The losses and mode birefringence for two different fibers
are investigated by finite-different time-domain method. The results show that
fiber 2 can achieve both high birefringence (larger than 0.022) and low
confinement loss (0.01 dB/m) in a wide THz frequency range. Moreover, compared
with a round solid-core fiber, guiding loss of the THz fiber caused by polymer
material absorption can be reduced effectively as a part of the mode power is
trapped in the air holes
- β¦