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Feature-aided pose estimation approach based on variational auto-encoder structure for spacecrafts

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Chinese Journal of Aeronautics 2024年第8期37卷 329-341页

作者： Yanfang LIU Rui ZHOU Desong DU Shuqing CAO Naiming QI Department of Aerospace Engineering Harbin Institute of TechnologyHarbin 150001China Suzhou Research institute of HIT Suzhou 215104China Shanghai institute of Spaceflight Control Technology Shanghai 201109China Shanghai Key Laboratory of Aerospace intelligent Control Technology Shanghai 201109China

Real-time 6 Degree-of-Freedom(DoF)pose estimation is of paramount importance for various on-orbit *** from the development of deep learning,Convolutional Neural Networks(CNNs)in feature extraction has yielded impressive achievements for spacecraft pose *** improve the robustness and interpretability of CNNs,this paper proposes a Pose Estimation approach based on Variational Auto-Encoder structure(PE-VAE)and a Feature-Aided pose estimation approach based on Variational Auto-Encoder structure(FA-VAE),which aim to accurately estimate the 6 DoF pose of a target *** methods treat the pose vector as latent variables,employing an encoder-decoder network with a Variational Auto-Encoder(VAE)*** enhance the precision of pose estimation,PE-VAE uses the VAE structure to introduce reconstruction mechanism with the whole ***,FA-VAE enforces feature shape constraints by exclusively reconstructing the segment of the target spacecraft with the desired *** evaluation against leading methods on public datasets reveals similar accuracy with a threefold improvement in processing speed,showcasing the significant contribution of VAE structures to accuracy enhancement,and the additional benefit of incorporating global shape prior features.

关键词： Pose estimation Variational auto-encoder Feature-aided Pose Estimation Approach On-orbit measurement tasks Simulated and experimental dataset

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

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Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU Yanyu SONG Wei FU Xiaoguo SONG Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong institute of Shipbuilding Technology Weihai 264209China China Machinery intelligent Equipment Innovation Research institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

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A causal multiomics study discriminates the early immune features of Ad5-vectored Ebola vaccine recipients

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The Innovation 2024年第3期5卷 77-87页

作者： Zhe Zhang Wenjing Yang Zhengshan Chen Haoang Chi Shipo Wu Wanru Zheng Ruochun Jin Busen Wang Yudong Wang Nan Huo Jinlong Zhang Xiaohong Song Liyang Xu Jun Zhang Lihua Hou Wei Chen institute of Biotechnology Academy of Military Medical SciencesBeijing 100071China Department of intelligent Data Science College of Computer Science and TechnologyNational University of Defense TechnologyChangsha 410073China intelligent Game and Decision Lab Academy of Military ScienceBeijing 100091China

The vaccine-induced innate immune response is essential for the generation of an antibody *** date,how Ad5-vectored vaccines are influenced by preexisting anti-Ad5 antibodies during activation of the early immune response remains ***,we investigated the specific alterations in GP1,2-specific IgG-related elements of the early immune response at the genetic,molecular,and cellular levels on days 0,1,3,and 7 after Ad5-EBOV *** a causal multiomics analysis,distinct early immune responses associated with GP1,2-specific IgG were observed in Ad5-EBOV recipients with a low level of preexisting anti-Ad5 *** study revealed the correlates of the Ad5-EBOV-induced IgG response and provided mechanistic evidence for overcoming preexisting Ad5 immunity during the administration of Ad5-vectored vaccines.

关键词： vaccine immunity alterations

Advancements in Humanoid Robots: A Comprehensive Review and Future Prospects

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 301-328页

作者： Yuchuang Tong Haotian Liu Zhengtao Zhang IEEE CAS Engineering Laboratory for intelligent Industrial Vision Institute of AutomationChinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China

This paper provides a comprehensive review of the current status, advancements, and future prospects of humanoid robots, highlighting their significance in driving the evolution of next-generation industries. By analyzing various research endeavors and key technologies, encompassing ontology structure,control and decision-making, and perception and interaction, a holistic overview of the current state of humanoid robot research is presented. Furthermore, emerging challenges in the field are identified, emphasizing the necessity for a deeper understanding of biological motion mechanisms, improved structural design,enhanced material applications, advanced drive and control methods, and efficient energy utilization. The integration of bionics, brain-inspired intelligence, mechanics, and control is underscored as a promising direction for the development of advanced humanoid robotic systems. This paper serves as an invaluable resource, offering insightful guidance to researchers in the field,while contributing to the ongoing evolution and potential of humanoid robots across diverse domains.

关键词： Future trends and challenges humanoid robots human-robot interaction key technologies potential applications

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Single-step-etched ultra-compact metamaterial grating coupler enabled by a hierarchical inverse design approach

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 119-126页

作者： Qiao Wang Ruiqi Luo Nan Liu Maojing Hou Bo Xiong Guandong Liu Wei Ma intelligent Network Research institute Zhejiang LabHangzhou 311100China State Key Laboratory of Modern Optical Instrumentation College of Information Science and Electronic EngineeringZhejiang UniversityHangzhou 310027China

With the concept of metamaterials introduced into integrated photonics,subwavelength structures have gained popularity for their ability to create devices with ultra-compact size,high performance,and versatile ***,traditional metamaterial design methods are usually based on empirical templates and physical approximations,lacking the ability to design free-form metamaterial structures and optimize entire devices *** this work,we propose a hierarchical inverse design approach that combines a conventional effective refractive index based metamaterial structures design with a follow-up global topology *** empirical metamaterial grating coupler design based on effective refractive index engineering faces inaccurate index extraction and insufficient approximation of wavevector matching conditions,which deteriorates coupling efficiency,especially for fully-etched devices with the decreased tapering ***,a subsequent overall topology optimization step can well compensate for the negative effect of the shrinking device footprint to increase the efficiency of the metamaterial grating *** demonstrate a 23μm×10μm ultra-compact metamaterial grating coupler with single-stepetched to couple light between a fiber and a 500 nm single-mode silicon waveguide in the *** measurement shows an insertion loss of 3.17 dB and a 3 dB bandwidth of 77 nm,making it the smallest footprint device ever reported.

关键词： waveguide hierarchical inverse

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A buffer overflow detection and defense method based on RiSC-V instruction set extension

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Cybersecurity 2024年第2期7卷 28-43页

作者： Chang Liu Yan-Jun Wu Jing-Zheng Wu Chen Zhao intelligent Software Research Center Institute of SoftwareChinese Academy of SciencesBejingChina University of Chinese Academy of Sciences BeijingChina State Key Laboratory of Computer Science Institute of SoftwareChinese Academy of SciencesBeijingChina

Buffer overflow poses a serious threat to the memory security of modern operating *** overwrites the con-tents of other memory areas by breaking through the buffer capacity limit,destroys the system execution environ-ment,and provides implementation space for various system attacks such as program control flow *** makes it a wide range of harms.A variety of security technologies have been proposed to deal with system security problems including buffer *** example,No eXecute(NX for short)is a memory management technology commonly used in Harvard *** can refuse the execution of code which residing in a specific memory,and can effectively suppress the abnormal impact of buffer overflow on control ***,in recent years,it has also been used in the field of system security,deriving a series of solutions based on NX technology,such as ExecShield,DEP,StackGuard,***,these security solutions often rely too much on the processor archi-tecture so that the protection coverage is insufficient and the accuracy is *** in the emerging system architecture field represented by RiSC-V,there is still a lack of effective solutions for buffer overflow *** the continuous rapid development of the system architecture,it is urgent to develop defense methods that are applicable to different system application environments and oriented to all executable memory spaces to meet the needs of system security ***,we propose BOP,A new system memory security design method based on RISC-V extended instructions,to build a RISC-V buffer overflow detection and defense system and deal with the buffer overflow threat in *** to this method,NX technology can be combined with program control flow analysis,and Nx bit mechanism can be used to manage the executability of memory space,so as to achieve a more granular detection and defense of buffer overflow attacks that may occur in RISC-V system

关键词： RISc-V Operating system security Buffer overflow Control flow hijacking Nx bit Xibop

Optical two-dimensional coherent spectroscopy of excitons in transition-metal dichalcogenides

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Frontiers of physics 2024年第2期19卷 141-148页

作者： YanZuo Chen ShaoGang Yu Tao Jiang XiaoJun Liu XinBin Cheng Di Huang State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China MOE Key Laboratory of Advanced Micro-Structured materials Shanghai Frontiers Science Center of Digital OpticsInstitute of Precision Optical Engineeringand School of Physics Science and EngineeringTongji UniversityShanghai 200092China Shanghai institute of intelligent Science and Technology Tongji UniversityShanghai 200092China

Exciton physics in atomically thin transition-metal dichalcogenides(TMDCs)holds paramount importance for fundamental physics research and prospective ***,the experimental exploration of exciton physics,including excitonic coherence dynamics,exciton many-body interactions,and their optical properties,faces challenges stemming from factors such as spatial heterogeneity and intricate many-body *** this perspective,we elaborate upon how optical two-dimensional coherent spectroscopy(2DCS)emerges as an effective tool to tackle the challenges,and outline potential directions for gaining deeper insights into exciton physics in forthcoming experiments with the advancements in 2DCS techniques and new materials.

关键词： monolayer transition-metal dichalcogenides two-dimensional coherent spectroscopy

A CSP-based retraining framework for motor imagery based brain-computer interfaces

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Science China(Information Sciences) 2024年第8期67卷 349-350页

作者： Xue JIANG Lubin MENG Xinru CHEN Dongrui WU Key Laboratory of Image Processing and intelligent Control School of Artificial Intelligence and AutomationHuazhong University of Science and Technology Shenzhen Huazhong University of Science and Technology Research institute

Motor imagery(MI) is a classic paradigm of electroencephalogram(EEG)-based brain-computer interfaces(BCIs). It entails individuals mentally imagining the movement of a body part without physically performing it. EEG s... 详细信息

关键词： Classification (of information)

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NiIr单原子合金气凝胶的电化学水活化行为调控及其电化学发光性能研究（英文）

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Science Bulletin 2024年第15期 2387-2394页

作者：灵灵习梦珍汪恒佳肖润石郑黎荣胡六永顾文玲朱成周 State Key Laboratory of Green Pesticide International Joint Research Center for Intelligent Biosensing Technology and Health College of Chemistry Central China Normal University Hubei Key Laboratory of Plasma Chemistry and Advanced materials Hubei Engineering Technology Research Center of Optoelectronic and New Energy Materials Wuhan Institute of Technology institute of High Energy Physics Chinese Academy of Sciences

The anodic oxygen evolution reaction is a well-acknowledged side reaction in traditional aqueous electrochemiluminescence(ECL) systems due to the generation and surface aggregation of oxygen at the electrode, which detrimentally impacts the stability and efficiency of ECL emission. However, the effect of reactive oxygen species generated during water oxidation on ECL luminophores has been largely overlooked. Taking the typical luminol emitter as an example, herein, we employed NiIr single-atom alloy aerogels possessing efficient water oxidation activity as a prototype co-reaction accelerator to elucidate the relationship between ECL behavior and water oxidation reaction kinetics for the first time. By regulating the concentration of hydroxide ions in the electrolyte, the electrochemical oxidation processes of both luminol and water are finely tuned. When the concentration of hydroxide ions in electrolyte is low,the kinetics of water oxidation is attenuated, which limits the generation of oxygen, effectively mitigates the influence of oxygen accumulation on the ECL strength, and offers a novel perspective for harnessing side reactions in ECL systems. Finally, a sensitive and stable sensor for antioxidant detection was constructed and applied to the practical sample detection.

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