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 Bi$_2$Se$_3$/ferromagnetic Co heterostructure, down to the sub-picosecond timescale. Compared to pure Bi$_2$Se$_3$ 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 Bi$_2$Se$_3$ 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 $K$ edge. Full multiple scattering ab initio calculations of Co XANES at the $K$ 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