192 research outputs found
Study on the mechanism of the overall evolution of Chinese students’ physical health testing system
Physical health test plays an important role in students’ physical health, since the reform and opening up, Chinese students’
physical health test has entered the track of benign development, experienced the reform in 1975, 2002, 2007, and the partial revision in
1982, 1990, 2014. With the continuous reform and revision of physical fi tness testing standards in the whole academic community, physical
fi tness testing standards have become a research hotspot in recent years.This review will study the evolution of the history of physical fi tness
testing system for Chinese students, infl uencing factors and existing problems
A Meta-Learning Perspective on Transformers for Causal Language Modeling
The Transformer architecture has become prominent in developing large causal
language models. However, mechanisms to explain its capabilities are not well
understood. Focused on the training process, here we establish a meta-learning
view of the Transformer architecture when trained for the causal language
modeling task, by explicating an inner optimization process that may happen
within the Transformer. Further, from within the inner optimization, we
discover and theoretically analyze a special characteristic of the norms of
learned token representations within Transformer-based causal language models.
Our analysis is supported by experiments conducted on pre-trained large
language models and real-world data
(3S,4R,4aS,7aR,12bS)-3-Cyclopropylmethyl-4a,9-dihydroxy-3-methyl-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methano-1-benzofuro[3,2-e]isoquinolin-3-ium 2,2,2-trifluoroacetate methanol solvate
In the title compound, C21H26F3NO6
+·CF3COO−·CH3OH or S-MNTX·CF3COO−·CH3OH (MNTX = methylnaltrexone), the conformation of the polycyclic backbone of the noroxymorphone skeleton can be simplified in terms of the angles between the least-squares planes of these rings. The dihedral angle between the cyclohexene and piperidine rings is 84.5 (6)°, while the dihedral angles between the planes of cyclohexane ring and the benzene, cyclohexene and piperidine rings, respectively, are 85.8 (6),80.0 (7) and 10.3 (7)°. In the crystal, molecules are linked by O—H⋯O hydrogen bonds. The trifluoroacetate F atoms are disordered in a 0.710 (14):0.710 (14) ratio. The absolute stereochemistry was inferred from the use of (4R,4aS,7aR,12bS)-3-(cyclopropylmethyl)-4a,9-dihydroxy-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one as one of the starting materials
PRO-Face S: Privacy-preserving Reversible Obfuscation of Face Images via Secure Flow
This paper proposes a novel paradigm for facial privacy protection that
unifies multiple characteristics including anonymity, diversity, reversibility
and security within a single lightweight framework. We name it PRO-Face S,
short for Privacy-preserving Reversible Obfuscation of Face images via Secure
flow-based model. In the framework, an Invertible Neural Network (INN) is
utilized to process the input image along with its pre-obfuscated form, and
generate the privacy protected image that visually approximates to the
pre-obfuscated one, thus ensuring privacy. The pre-obfuscation applied can be
in diversified form with different strengths and styles specified by users.
Along protection, a secret key is injected into the network such that the
original image can only be recovered from the protection image via the same
model given the correct key provided. Two modes of image recovery are devised
to deal with malicious recovery attempts in different scenarios. Finally,
extensive experiments conducted on three public image datasets demonstrate the
superiority of the proposed framework over multiple state-of-the-art
approaches
Time-interval visual saliency prediction in mammogram reading
Radiologists’ eye movements during medical image interpretation reflect their perceptual-cognitive behaviour and correlate with diagnostic decisions. Previous study has shown the
significance of gaze behaviour of different time intervals for
the decision-making process. Being able to automatically predict the visual attention of radiologists for different reading
phases would enhance the reliability and explainability of artificial intelligence (AI) in diagnostic imaging. In this paper,
we investigate the time-interval visual saliency in mammogram reading. We propose a novel visual saliency prediction
model based on deep learning, which predicts a sequence of
time-interval saliency maps for an input mammogram. Experimental results demonstrate the efficacy of the proposed
time-interval saliency model
Ultrafast Spin-To-Charge Conversion at the Surface of Topological Insulator Thin Films
Strong spin-orbit coupling, resulting in the formation of
spin-momentum-locked surface states, endows topological insulators with
superior spin-to-charge conversion characteristics, though the dynamics that
govern it have remained elusive. Here, we present an all-optical method that
enables unprecedented tracking of the ultrafast dynamics of spin-to-charge
conversion in a prototypical topological insulator BiSe/ferromagnetic
Co heterostructure, down to the sub-picosecond timescale. Compared to pure
BiSe or Co, we observe a giant terahertz emission in the
heterostructure than originates from spin-to-charge conversion, in which the
topological surface states play a crucial role. We identify a 0.12-picosecond
timescale that sets a technological speed limit of spin-to-charge conversion
processes in topological insulators. In addition, we show that the
spin-to-charge conversion efficiency is temperature independent in BiSe
as expected from the nature of the surface states, paving the way for designing
next-generation high-speed opto-spintronic devices based on topological
insulators at room temperature.Comment: 19 pages, 4 figure
XANES investigation of the local structure of Co nanoclusters embedded in Ag
Ion-implanted cobalt atoms into a silver matrix with a layer thickness of about 20 nm were studied by x-ray absorption near-edge spectroscopy (XANES) at the Co edge. Full multiple scattering ab initio calculations of Co XANES at the edge provide a phase fingerprint to distinguish the Co structure of samples prepared at different doses and annealing temperatures. The bcc Co phase is formed for the as-prepared sample with 6 at. % and the fcc Co phase is formed at the expense of the bcc phase for the sample with 12 at. % after annealing at $400\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}.
Analysis of video quality induced spatio-temporal saliency shifts
Human viewers’ eye movements reflect their perceptual responses to visual signals. Previous research has shown that distortions in videos cause spatio-temporal gaze shifts, which means gaze behaviour is related to video quality perception. It would be highly beneficial to understand gaze behaviour of viewing videos of varying perceived quality. However, little is known about the interactions between gaze, video content and distortions. In this paper, based on our eye-tracking database for video quality (SVQ160), we perform systematic analyses to reveal the impact of video content (VC) and time order (TO) on gaze shifts. Findings and quantitative methods for gaze behaviour can be used to develop advanced video quality metrics and video processing algorithms
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