414 research outputs found
Quantum resource studied from the perspective of quantum state superposition
Quantum resources,such as discord and entanglement, are crucial in quantum
information processing. In this paper, quantum resources are studied from the
aspect of quantum state superposition. We define the local superposition (LS)
as the superposition between basis of single part, and nonlocal superposition
(NLS) as the superposition between product basis of multiple parts. For quantum
resource with nonzero LS, quantum operation must be introduced to prepare it,
and for quantum resource with nonzero NLS, nonlocal quantum operation must be
introduced to prepare it. We prove that LS vanishes if and only if the state is
classical and NLS vanishes if and only if the state is separable. From this
superposition aspect, quantum resources are categorized as superpositions
existing in different parts. These results are helpful to study quantum
resources from a unified frame.Comment: 9 pages, 4 figure
Attention Focusing for Neural Machine Translation by Bridging Source and Target Embeddings
In neural machine translation, a source sequence of words is encoded into a
vector from which a target sequence is generated in the decoding phase.
Differently from statistical machine translation, the associations between
source words and their possible target counterparts are not explicitly stored.
Source and target words are at the two ends of a long information processing
procedure, mediated by hidden states at both the source encoding and the target
decoding phases. This makes it possible that a source word is incorrectly
translated into a target word that is not any of its admissible equivalent
counterparts in the target language.
In this paper, we seek to somewhat shorten the distance between source and
target words in that procedure, and thus strengthen their association, by means
of a method we term bridging source and target word embeddings. We experiment
with three strategies: (1) a source-side bridging model, where source word
embeddings are moved one step closer to the output target sequence; (2) a
target-side bridging model, which explores the more relevant source word
embeddings for the prediction of the target sequence; and (3) a direct bridging
model, which directly connects source and target word embeddings seeking to
minimize errors in the translation of ones by the others.
Experiments and analysis presented in this paper demonstrate that the
proposed bridging models are able to significantly improve quality of both
sentence translation, in general, and alignment and translation of individual
source words with target words, in particular.Comment: 9 pages, 6 figures. Accepted by ACL201
Negative exponential behavior of image mutual information for pseudo-thermal light ghost imaging: Observation, modeling, and verification
When use the image mutual information to assess the quality of reconstructed
image in pseudo-thermal light ghost imaging, a negative exponential behavior
with respect to the measurement number is observed. Based on information theory
and a few simple and verifiable assumptions, semi-quantitative model of image
mutual information under varying measurement numbers is established. It is the
Gaussian characteristics of the bucket detector output probability distribution
that leads to this negative exponential behavior. Designed experiments verify
the model.Comment: 13 pages, 6 figure
Binary sampling ghost imaging: add random noise to fight quantization caused image quality decline
When the sampling data of ghost imaging is recorded with less bits, i.e.,
experiencing quantization, decline of image quality is observed. The less bits
used, the worse image one gets. Dithering, which adds suitable random noise to
the raw data before quantization, is proved to be capable of compensating image
quality decline effectively, even for the extreme binary sampling case. A brief
explanation and parameter optimization of dithering are given.Comment: 8 pages, 7 figure
Modified cam-clay model with dynamic shear modulus under cyclic loads
In order to study the dynamic characteristics of clay under metro loads, a dynamic triaxial test for clay was conducted. The function formula between the dynamic shear modulus and the number of oscillation periods was presented to calculate and analyze the dynamic characteristics of clay, then the function formula applicability was verified for different regional clays. In addition, the relationship between dynamic shear modulus and the parameters of cam-clay was established. The function formula for calculating dynamic shear modulus can be generalized to apply to the cam-clay model. The results show that the dynamic shear modulus function formula can be well applied. This modified cam-clay model can not only describe hysteresis loops, but also consider the effects of loading frequency on the dynamic characteristics of clay. Therefore, it is convenient to study the dynamic characteristics of clay under metro loads for theoretical analysis and verification
Identification of 4FGL uncertain sources at Higher Resolutions with Inverse Discrete Wavelet Transform
In the forthcoming era of big astronomical data, it is a burden to find out
target sources from ground-based and space-based telescopes. Although Machine
Learning (ML) methods have been extensively utilized to address this issue, the
incorporation of in-depth data analysis can significantly enhance the
efficiency of identifying target sources when dealing with massive volumes of
astronomical data. In this work, we focused on the task of finding AGN
candidates and identifying BL Lac/FSRQ candidates from the 4FGL DR3 uncertain
sources. We studied the correlations among the attributes of the 4FGL DR3
catalogue and proposed a novel method, named FDIDWT, to transform the original
data. The transformed dataset is characterized as low-dimensional and
feature-highlighted, with the estimation of correlation features by Fractal
Dimension (FD) theory and the multi-resolution analysis by Inverse Discrete
Wavelet Transform (IDWT). Combining the FDIDWT method with an improved
lightweight MatchboxConv1D model, we accomplished two missions: (1) to
distinguish the Active Galactic Nuclei (AGNs) from others (Non-AGNs) in the
4FGL DR3 uncertain sources with an accuracy of 96.65%, namely, Mission A; (2)
to classify blazar candidates of uncertain type (BCUs) into BL Lacertae objects
(BL Lacs) or Flat Spectrum Radio Quasars (FSRQs) with an accuracy of 92.03%,
namely, Mission B. There are 1354 AGN candidates in Mission A, 482 BL Lacs
candidates and 128 FSRQ candidates in Mission B were found. The results show a
high consistency of greater than 98% with the results in previous works. In
addition, our method has the advantage of finding less variable and relatively
faint sources than ordinary methods
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