1,293 research outputs found
A Multi-task Learning Approach for Improving Product Title Compression with User Search Log Data
It is a challenging and practical research problem to obtain effective
compression of lengthy product titles for E-commerce. This is particularly
important as more and more users browse mobile E-commerce apps and more
merchants make the original product titles redundant and lengthy for Search
Engine Optimization. Traditional text summarization approaches often require a
large amount of preprocessing costs and do not capture the important issue of
conversion rate in E-commerce. This paper proposes a novel multi-task learning
approach for improving product title compression with user search log data. In
particular, a pointer network-based sequence-to-sequence approach is utilized
for title compression with an attentive mechanism as an extractive method and
an attentive encoder-decoder approach is utilized for generating user search
queries. The encoding parameters (i.e., semantic embedding of original titles)
are shared among the two tasks and the attention distributions are jointly
optimized. An extensive set of experiments with both human annotated data and
online deployment demonstrate the advantage of the proposed research for both
compression qualities and online business values.Comment: 8 Pages, accepted at AAAI 201
Intraventricular Hemorrhage Caused by Lateral Ventricular Meningioma: A Case Report
Meningiomas causing intracranial hemorrhage are rare, and hemorrhage from a lateral ventricular meningioma seems to be even rarer. We report a case of trigonal meningioma in a 43-year-old woman who presented with intraventricular hemorrhage, and describe the CT, MRI and angiographic findings
Planar peristrophic multiplexing metasurfaces
As a promising counterpart of two-dimensional metamaterials, metasurfaces enable to arbitrarily control the wavefront of light at subwavelength scale and hold promise for planar holography and applicable multiplexing devices. Nevertheless, the degrees of freedom (DoF) to orthogonally multiplex data have been almost exhausted. Compared with state-of-the-art methods that extensively employ the orthogonal basis such as wavelength, polarization or orbital angular momentum, we propose an unprecedented method of peristrophic multiplexing by combining the spatial frequency orthogonality with the subwavelength detour phase principle. The orthogonal relationship between the spatial frequency of incident light and the locally shifted building blocks of metasurfaces can be regarded as an additional DoF. We experimentally demonstrate the viability of the multiplexed holograms. Moreover, this newly-explored orthogonality is compatible with conventional DoFs. Our findings will contribute to the development of multiplexing metasurfaces and provide a novel solution to nanophotonics, such as large-capacity chip-scale devices and highly integrated communication
Unified understanding of superconductivity and Mott transition in alkali-doped fullerides from first principles
Alkali-doped fullerides A3C60 (A = K, Rb, Cs) are surprising materials where conventional phonon-mediated superconductivity and unconventional Mott physics meet, leading to a remarkable phase diagram as a function of volume per C60 molecule. We address these materials with a state-of-the-art calculation, where we construct a realistic low-energy model from first principles without using a priori information other than the crystal structure and solve it with an accurate many-body theory. Remarkably, our scheme comprehensively reproduces the experimental phase diagram including the low-spin Mott-insulating phase next to the superconducting phase. More remarkably, the critical temperatures Tc\u2019s calculated from first principles quantitatively reproduce the experimental values. The driving force behind the surprising phase diagram of A3C60 is a subtle competition between Hund\u2019s coupling and Jahn-Teller phonons, which leads to an effectively inverted Hund\u2019s coupling. Our results establish that the fullerides are the first members of a novel class of molecular superconductors in which the multiorbital electronic correlations and phonons cooperate to reach high Tc s-wave superconductivity
Mechanisms controlling dissolved CO2 over-saturation in the Three Gorges Reservoir area
The emission of CO2 to the atmosphere from inland waters is an important part of the global carbon cycle. In this study, we made spatial and temporal measurements of CO2 partial pressure (pCO2) along the Three Gorges Dam system. The pCO2 ranged from 619 to 2383 μatm and was supersaturated relative to atmospheric CO2. Further, pCO2 showed obvious spatial and temporal variations: pCO2 at the high-flow season was much lower than that at the low-flow season near the upstream part of the reservoir, whereas pCO2 in the reservoir water and after the dam showed an opposite seasonal trend. Organic matter mineralization produced more CO2 in the surface water of the reservoir area at the high-flow season and should be responsible for the δ13C-depleted dissolved inorganic carbon (δ13CDIC). In addition, organic carbon mineralization is sensitive to temperature variability, which is expected to be an important driver of the dissolved CO2 over-saturation in the reservoir. This study suggested that the construction of Three Gorges Reservoir increased the water transit time and accelerated the organic carbon mineralization in the Changjiang River. The results indicate that carbon cycling changes markedly in large impounded rivers
Band-filling effects on electron-phonon properties of normal and superconducting state
We address the effect of band filling on the effective electron mass
and the superconducting critical temperature in a electron-phonon system.
We compare the vertex corrected theory with the non-crossing approximation of
the Holstein model within a local approximation. We identify two regions of the
electron density where and are enhanced or decreased by the
inclusion of the vertex diagrams. We show that the crossover between the
enhancement at low density and the decrease towards half filling is almost
independent of the microscopic electron-phonon parameters. These different
behaviors are explained in terms of the net sign of the vertex diagrams which
is positive at low densities and negative close to half filling. Predictions of
the present theory for doped MgB, which is argued to be in the low density
regime, are discussed.Comment: 13 revtex pages, figures eps include
Warped Riemannian metrics for location-scale models
The present paper shows that warped Riemannian metrics, a class of Riemannian
metrics which play a prominent role in Riemannian geometry, are also of
fundamental importance in information geometry. Precisely, the paper features a
new theorem, which states that the Rao-Fisher information metric of any
location-scale model, defined on a Riemannian manifold, is a warped Riemannian
metric, whenever this model is invariant under the action of some Lie group.
This theorem is a valuable tool in finding the expression of the Rao-Fisher
information metric of location-scale models defined on high-dimensional
Riemannian manifolds. Indeed, a warped Riemannian metric is fully determined by
only two functions of a single variable, irrespective of the dimension of the
underlying Riemannian manifold. Starting from this theorem, several original
contributions are made. The expression of the Rao-Fisher information metric of
the Riemannian Gaussian model is provided, for the first time in the
literature. A generalised definition of the Mahalanobis distance is introduced,
which is applicable to any location-scale model defined on a Riemannian
manifold. The solution of the geodesic equation is obtained, for any Rao-Fisher
information metric defined in terms of warped Riemannian metrics. Finally,
using a mixture of analytical and numerical computations, it is shown that the
parameter space of the von Mises-Fisher model of -dimensional directional
data, when equipped with its Rao-Fisher information metric, becomes a Hadamard
manifold, a simply-connected complete Riemannian manifold of negative sectional
curvature, for . Hopefully, in upcoming work, this will be
proved for any value of .Comment: first version, before submissio
Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Zhang, M., Guo, Z., Xu, S., Barry, P. H., Sano, Y., Zhang, L., Halldorsson, S. A., Chen, A.-T., Cheng, Z., Liu, C.-Q., Li, S.-L., Lang, Y.-C., Zheng, G., Li, Z., Li, L., & Li, Y. Linking deeply-sourced volatile emissions to plateau growth dynamics in southeastern Tibetan Plateau. Nature Communications, 12(1), (2021): 4157, https://doi.org/10.1038/s41467-021-24415-y.The episodic growth of high-elevation orogenic plateaux is controlled by a series of geodynamic processes. However, determining the underlying mechanisms that drive plateau growth dynamics over geological history and constraining the depths at which growth originates, remains challenging. Here we present He-CO2-N2 systematics of hydrothermal fluids that reveal the existence of a lithospheric-scale fault system in the southeastern Tibetan Plateau, whereby multi-stage plateau growth occurred in the geological past and continues to the present. He isotopes provide unambiguous evidence for the involvement of mantle-scale dynamics in lateral expansion and localized surface uplift of the Tibetan Plateau. The excellent correlation between 3He/4He values and strain rates, along the strike of Indian indentation into Asia, suggests non-uniform distribution of stresses between the plateau boundary and interior, which modulate southeastward growth of the Tibetan Plateau within the context of India-Asia convergence. Our results demonstrate that deeply-sourced volatile geochemistry can be used to constrain deep dynamic processes involved in orogenic plateau growth.This work was supported by China Seismic Experimental Site (CSES) (2019CSES0104), the Strategic Priority Research Program (B) of Chinese Academy of Sciences (XDB26000000), the National Key Research and Development Program of China (2020YFA0607700), the National Natural Science Foundation of China (41930642, 41602341, 41772355, and 41702361), the Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (2019QZKK0702), and the United Laboratory of High-Pressure Physics and Earthquake Science (2019HPPES02). P.H.B. was supported by the US National Science Foundation EAR Grant 1144559 during a portion of this work
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