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Theoretical analysis of the elastic Kelvin-Helmholtz instability in explosive weldings

Defence technology（防务技术） 2024年第2期32卷 521-528页

作者： Yuanbo Sun Jianning Gou Cheng Wang Qiang Zhou Rui Liu Pengwan Chen Tonghui Yang Xiang Zhao State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Beijing HIWING Scientific and Technological Information Institute Beijing100084China School of Aerospace Engineering Tsinghua UniversityBeijing100084China

By considering the joint effects of the Kelvin-Helmholtz(KH) and Rayleigh-Taylor(RT) instabilities, this paper presents an interpretation of the wavy patterns that occur in explosive welding. It is assumed that the elasticity of the material at the interface effectively determines the wavelength, because explosive welding is basically a solid-state welding process. To this end, an analytical model of elastic hydrodynamic instabilities is proposed, and the most unstable mode is selected in the solid phase. Similar approaches have been widely used to study the interfacial behavior of solid metals in high-energy-density physics. By comparing the experimental and theoretical results, it is concluded that thermal softening,which significantly reduces the shear modulus, is necessary and sufficient for successful welding. The thermal softening is verified by theoretical analysis of the increase in temperature due to the impacting and sliding of the flyer and base plates, and some experimental observations are qualitatively *** summary, the combined effect of the KH and RT instabilities in solids determines the wavy morphology, and our theoretical results are in good qualitative agreement with experimental and numerical observations.

关键词： Explosive welding Hydrodynamic instabilities Elasticity

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CASKA-CRT: Chinese Remainder Theorem Empowered Certificateless Aggregate Signcryption Scheme with key Agreement in IoVs

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on Intelligent Vehicles 2024年 1-16页

作者： Hou, Yingzhe Cao, Yue Xiong, Hu Sun, Zhili Mumtaz, Shahid Tian, Daxin School of Cyber Science and Engineering Wuhan University Wuhan China School of Information and Software Engineering University of Electronic Science and Technology of China Chengdu China Institute of Communication Systems University of Surrey Guildford U.K Department of Applied Informatics Silesian University of Technology Akademicka Gliwice Poland State Key Laboratory of Vehicle-Infrastructure Integrated ITS the State Key Laboratory of Intelligent Transportation System and the School of Transportation Science and Engineering Beihang University Beijing China

To enhance the privacy of messages in Internet of Vehicles (IoVs), it is critical to preserve the communication security between Road Side Unit (RSU) and numerous vehicles. The primitive of signcryption is introduced to guarantee the confidentiality, integrity and unforgeability of transmitted messages. Nevertheless, the existing signcryption schemes fail to achieve a balance between security and efficiency. In this paper, we construct a Chinese remainder theorem (CRT) empowered certificateless aggregate signcryption scheme with key agreement (CASKA-CRT). As the vehicle joins and leaves dynamically, the proposed scheme can ensure the dynamic security via one modulo division operation. Besides, the certificateless aggregate signcryption and key agreement mechanisms are embedded. The former idea can both address the certificate management and key escrow problems, while the latter technology can create authentication as a premise of secure communication. Based on this construction, the hash-to-group operation and bilinear pairing are avoided, to realize a faster verification with the increased number of messages. Moreover, the security of proposed scheme is proved under the random oracle model. Finally, the performance analysis demonstrates the advantage of CASKA-CRT in terms of security and reliability over related works. IEEE

关键词： Public key cryptography

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An Evolutionary Multitasking Algorithm for Efficient Multiobjective Recommendations

IEEE Transactions on Artificial Intelligence

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IEEE Transactions on Artificial Intelligence 2025年第3期6卷 518-532页

作者： Tian, Ye Ji, Luke Hu, Yiwei Ma, Haiping Wu, Le Zhang, Xingyi Anhui University Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Computer Science and Technology Hefei230601 China Anhui University Institutes of Physical Science and Information Technology Hefei230601 China Hefei University of Technology Key Laboratory of Knowledge Engineering with Big Data Hefei230029 China

Represented by evolutionary algorithms and swarm intelligence algorithms, nature-inspired metaheuristics have been successfully applied to recommender systems and amply demonstrated effectiveness, in particular, for multiobjective recommendation. Owing to the population-based search paradigm, these algorithms can produce a number of recommendation lists, making diverse tradeoffs between multiple metrics and meeting the requirements of accuracy, novelty, diversity, and other user preferences. However, these algorithms are criticized for the low efficiency of the optimization process, especially when the number of users is large. To address this issue, this article proposes an evolutionary multitasking-based recommendation method, where each task corresponds to a user and all the tasks are optimized simultaneously, thus highly improving the efficiency of recommendation. To enhance the convergence speed, all the users are divided into multiple populations according to the similarity between their preferences, where each population evolves with internal knowledge transfer between users, and all the populations evolve with external knowledge transfer between populations. Experimental results on various datasets verify that the proposed method can better balance between multiple metrics than classical and deep neural network-based recommendation methods and exhibits significantly higher efficiency than evolutionary multiobjective optimization-based recommendation methods. © 2024 IEEE. All rights reserved.

关键词： Multiobjective optimization

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Irregular adaptive refinement network for semantic segmentation of high-resolution remote sensing images

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Journal of Intelligent and Fuzzy systems 2024年第5-6期46卷 11235-11246页

作者： Deng, Lulu Zhang, Changlun He, Qiang Wang, Hengyou Huo, Lianzhi Mu, Haibing Science School Beijing University of Civil Engineering and Architecture Beijing China Aerospace Information Research Institute Chinese Academy of Sciences Beijing China Key Laboratory of Communication and Information System Beijing Jiaotong University Beijing China

The semantic segmentation of high-resolution remote sensing images has broad application prospects in land cover classification, road extraction, urban planning and other fields. To alleviate the influence of the large data volume and complex background of high-resolution remote sensing images, the usual approach is to downsample them or cut them into small pieces for separate processing. Even if combining the two methods can improve the segmentation efficiency, it ignores the differences between the middle and the edge regions. Therefore, we consider the characteristics of large and irregular region in high-resolution remote sensing images, and then propose an irregular adaptive refinement network to locate the irregular edge region, which will be refined adaptively. Specifically, on the basis of effectively preserving the global and local information, the prediction confidence is calculated to locate pixel points that are poorly segmented, so as to form irregular regions requiring further refinement, avoiding to ‘over-refine’ intermediate region with good segmentation. At the same time, considering the difference in the refinement degree of different pixels, we propose to adaptively integrate the local segmentation results to refine the coarse segmentation results. In addition, in order to bridge the gap between the two extreme ends of the scale space, we introduce a multi-scale framework. Finally, we conducted experiments on the Deepglobe dataset showing that the proposed method performed 0.37% to 0.87% better than the previous state-of-the-art methods in terms of mean Intersection over Union (mIoU). © 2024 – IOS Press.

关键词： Semantic Segmentation

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Fiber Bragg gratings inscription with a single UV laser pulse by high-temperature arc pretreatment

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Optics Express 2025年第10期33卷 21692-21706页

作者： Xin, Jingtao Liao, Jingjing Yu, Chenbo Li, Qihui Zhu, Lianqing Beijing Information Science and Technology University Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument Beijing100101 China Guangzhou Nansha Intelligent Photonic Sensing Research Institute Guangzhou100094 China Beijing Information Science and Technology University Beijing Laboratory of Optical Fiber Sensing and System Beijing130033 China

This study proposes a high-temperature arc discharge pretreatment method to enhance the photosensitivity of hydrogen-loaded germanium-doped fibers for single-pulse FBG inscription. By coupling hydrogen diffusion dynamics with hydroxyl reaction kinetics, a numerical model based on Fick’s law and Arrhenius equations was established. Finite difference analysis revealed that 400°C with 50 ms heating maximizes hydroxyl concentration while suppressing hydrogen escape. In the experiments study, the pretreatment temperature and duration are controlled by adjusting the electrode discharge power and discharge time. The effectiveness of fiber sensitization is verified through single-pulse grating writing using a phase mask and a 248 nm ultraviolet laser. After optimizing the heat treatment parameters, fiber Bragg gratings (FBGs) with a reflectivity exceeding 83.7% were successfully written using a single pulse laser of 160mJ, representing a 130-fold improvement compared to the results obtained without heat treatment. This method not only enhances the efficiency of FBG writing but also fundamentally mitigates the issue of grating erasure, significantly reducing the stability requirements for the writing system. © 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

关键词： Fiber Bragg gratings

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Characterization of ultraviolet communication in a mixed aerosol environment

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Optoelectronics Letters 2025年第2期21卷 77-84页

作者： ZHAO Taifei SUN Yuxin WANG Wuxin ZHANG Haijun PAN Feixiang WU Hao Artificial Intelligence Key Laboratory of Sichuan Province Sichuan University of Science&EngineeringZigong 643000China Faculty of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China

Wireless ultraviolet (UV) has strong scattering characteristics and can communicate through non-direct *** UV signals are transmitted in the atmosphere,they are affected by the absorption and scattering effects of atmospheric particles and atmospheric turbulence,resulting in attenuation of UV signal energy and reduced reliability of the communication *** paper focuses on the channel model of UV non-direct-view single scattering communication,and simulates and analyzes the communication characteristics of UV light in atmospheric turbulence and mixed aerosol environment under horizontal,vertical and oblique range communication *** results show that at equal relative humidity,the wireless UV non-directive scattering communication performance for vertical communication scenarios is more affected by the mixed aerosol environment and the communication performance is worse.

关键词： communication scattering ultraviolet

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Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators

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National science Review 2024年第2期11卷 15-23页

作者： Rui Chen Hai-Peng Sun Mingqiang Gu Chun-Bo Hua Qihang Liu Hai-Zhou Lu X.C.Xie Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) International Quantum Academy Institute for Theoretical Physics and Astrophysics University of Würzburg School of Electronic and Information Engineering Hubei University of Science and Technology Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Shenzhen Key Laboratory of Quantum Science and Engineering International Center for Quantum Materials School of PhysicsPeking University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

关键词： layerHall effect hidden Berry curvature antiferromagnetic insulator axion insulator, quantum transport

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RESEARCH ON GAIT RECOGNITION BY USING 1DCNN BASED ON LOWER LIMB KINEMATIC POSTURE DATA 10

RESEARCH ON GAIT RECOGNITION BY USING 1DCNN BASED ON LOWER L...

引用

10th International Symposium on Test Automation and Instrumentation, ISTAI 2024

作者： Li, Mu Ma, Chao Wang, Shaohong Key Laboratory of Modern Measurement and Control Technology Ministry of Edu. Beijing Information Science and Technology University Beijing China Beijing Key Laboratory of Measurement and Control of Mechanical and Electrical System Beijing Information Science and Technology University Beijing China

ISBN: (纸本)9781837242672

Gait recognition refers to the process of realizing the detection of human identity or health status and other information according to the characteristics of human plantar pressure, video images or human dynamics indicators. With the advantages of non-contact, non-aggression, no need for cooperation and easy to collect, gait recognition technology has been widely used in recent years in the field of public security criminal investigation, medical care, intelligent transportation and other fields. In this study, to meet the needs of gait recognition, IMU sensors are used to acquire human lower limb motion posture data and wavelet transform is used to decompose several components. Then the components were determined and the optimized 1DCNN model is used to carry out gait recognition research. The results showed that the optimized 1DCNN model for gait recognition task exhibits excellent performance with up to 95% accuracy, 96% recall and Fl value, as well as good computational efficiency, which is valuable for clinical automatic gait recognition analysis, rehabilitation engineering and criminal investigation work. Although there are some errors in some gait classifications, our study provides directions for further optimization of the algorithm to improve the accuracy and robustness of gait recognition. © The Institution of engineering & technology 2024.

关键词： Crime

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Cryptanalysis of Full-Round Magpie Block Cipher

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Chinese Journal of Electronics 2023年第2期32卷 217-224页

作者： YANG Yunxiao SUN Bing LIU Guoqiang College of Liberal Arts and Sciences National University of Defense Technology State Key Laboratory of Cryptology Hunan Engineering Research Center of Commercial Cryptography Theory and Technology Innovation State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Science

Magpie is a lightweight block cipher proposed by Li et al. in Acta Electronica Sinica volumn 45,issue 10. It adopts an substitution-permutation network（SPN） structure with a block size of 64 bits and the key size of 96 bits, respectively. To achieve the consistency of the encryption and decryption, which is both hardware and software friendly, 16 bits of the key are used as control signals to select S-boxes and another 16 bits of the key are used to determine the order of the operations. As the designers claimed, the security might be improved as different keys generate different ciphers. This paper analyzes the security of Magpie, studies the difference propagation of Magpie, and finally finds that the cipher has a set of 280weak keys which makes the full-round encryption weak, and corrects the lower bound of the number of active S-boxes to 10 instead of 25 proposed by the designers. In the weak key model, the security of the cipher is reduced by the claimed 280to only 4×216.

关键词： Ciphers Force Aerospace electronics Software Hardware Encryption Security

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Unintentional emissions of polychlorinated naphthalenes in China:Sources,composition,and historical trends

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Journal of Environmental sciences 2025年第2期148卷 221-229页

作者： Ye Huang Lin Huang Ying Li Nazupar Sidikjan Yunshan Zhang Yan Chen Yangmin Chen Ye Li Wei Du Long Chen YanWu Shanshan Zhang Jing Yang Wenjun Meng Guofeng Shen Min Liu Shu Tao Key Laboratory of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China Yunnan Provincial Key Laboratory of Soil Carbon Sequestration and Pollution Control Faculty of Environmental Science&EngineeringKunming University of Science&TechnologyKunming 650500China Laboratory of Earth Surface Processes College of Urban and Environmental SciencePeking UniversityBeijing 100871China

Polychlorinated naphthalenes(PCNs)are detrimental to human health and the *** the commercial production of PCNs banned,unintentional releases have emerged as a significant environmental ***,relevant information is still *** this study,provincial emissions for eight PCNs homologues from 37 sources in the Chinese mainland during the period of 1960-2019 were estimated based on a source-specific and time-varying emission factor *** results showed that the total PCNs emissions in 2019 reached 757.0 kg with Hebei ranked at the top among all the provinces and iron&steel industry as the biggest ***-chlorinated PCNs comprised 90%of emissions by mass,while highly chlorinated PCNs dominated in terms of toxicity,highlighting divergent priorities for mitigating emissions and safeguarding human *** emissions showed an overall upward trend from 1960 to 2019 driven by emission increase from iron&steel industry in terms of source,and from North China and East China in terms of geographic ***-capita emissions followed an inverted U-shaped environmental Kuznets curvewhile emission intensities decreased with increasing per-capita Gross Domestic Product(GDP)following a nearly linear pattern when log-transformed.

关键词： PCNs Emission inventory Emission factor Composition profile Emission intensity Chinese mainland

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