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A Survey on Blockchain-Based Federated Learning:Categorization,Application and Analysis

Computer Modeling in Engineering & sciences 2024年第6期139卷 2451-2477页

作者： Yuming Tang Yitian Zhang Tao Niu Zhen Li Zijian Zhang Huaping Chen Long Zhang School of Cyberspace science&technology Beijing Institute of TechnologyBeijing100081China School of Computer science&technology Beijing Institute of TechnologyBeijing100081China Southeast institute of Information technology Beijing Institute of TechnologyPutian351100China Qianxin technology Group Co. Ltd.Beijing100044China

Federated Learning(FL),as an emergent paradigm in privacy-preserving machine learning,has garnered significant interest from scholars and engineers across both academic and industrial *** its innovative approach to model training across distributed networks,FL has its vulnerabilities;the centralized server-client architecture introduces risks of single-point ***,the integrity of the global model—a cornerstone of FL—is susceptible to compromise through poisoning attacks by malicious *** attacks and the potential for privacy leakage via inference starkly undermine FL’s foundational privacy and security *** these reasons,some participants unwilling use their private data to train a model,which is a bottleneck in the development and industrialization of federated *** technology,characterized by its decentralized ledger system,offers a compelling solution to these *** inherently prevents single-point failures and,through its incentive mechanisms,motivates participants to contribute computing ***,blockchain-based FL(BCFL)emerges as a natural progression to address FL’s *** study begins with concise introductions to federated learning and blockchain technologies,followed by a formal analysis of the specific problems that FL *** discusses the challenges of combining the two technologies and presents an overview of the latest cryptographic solutions that prevent privacy leakage during communication and incentives in *** addition,this research examines the use of BCFL in various fields,such as the Internet of Things and the Internet of ***,it assesses the effectiveness of these solutions.

关键词： Federated learning blockchain privacy-preserving

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Truly optimal semi-active damping to control free vibration of a single degree of freedom system

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 142-145页

作者： Viet Duc La Ngoc Tuan Nguyen institute of Mechanics Vietnam Academy of Science and TechnologyHanoi 10000Vietnam Graduate University of science and technology Vietnam Academy of Science and TechnologyHanoi 10000Vietnam

This paper studies a single degree of freedom system under free vibration and controlled by a general semiactive damping.A general integral of squared error is considered as the performance index.A one-time switching damping controller is proposed and *** pontryagin maximum principle is used to prove that no other form of semi-active damping can provide the better performance than the proposed one-time switching damping.

关键词： Analytical optimization Quadratic integral Lyapunov equation Pontryagin maximum principle

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Fast fixed-time three-dimensional terminal guidance with non-concave trajectory constraint

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Chinese Journal of Aeronautics 2024年第3期37卷 208-218页

作者： Youmin GONG Yanning GUO Yueyong LYU Dongyu LI Guangfu MA Department of Control science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Cyber science and technology Beihang UniversityBeijing 100191China

Focusing on the non-concave trajectory constraint,a sliding-mode-based nonsingular feedback fast fixed-time three-dimensional terminal guidance of rotor unmanned aerial vehicle landing,planetary landing and spacecraft rendezvous and docking terminal phase with external disturbance is investigated in this ***,a fixed-time observer based on real-time differentiator is developed to compensate for the external disturbance,whose estimation error can converge to zero after a time independent of the initial ***,a sliding surface ensuring fixed-time convergence is *** sliding surface can guarantee that the vehicle achieves a non-concave trajectory,which is better for avoiding collision and maintaining the visibility of the landing site or docking ***,the nonsingular guidance ensuring the fixed-time convergence of the sliding surface is proposed,which is continuous and chatter *** last,three numerical simulations of Mars landing are performed to validate the effectiveness and correctness of the designed scheme.

关键词： Three-dimensional Terminal guidance Non-concave trajectory constraint Fast fixed-time control Sliding mode control

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Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

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Defence technology（防务技术） 2024年第1期31卷 58-72页

作者： Yong-Pan Duan Run-Qiang Chi Bao-Jun Pang Yuan Cai Hypervelocity Impact Research Center Harbin Institute of TechnologyHarbin150080China College of science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms

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Large eddy simulation of boundary layer combustion of hydrogen and hydrocarbon fuel films in a modeled scramjet combustor

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Chinese Journal of Aeronautics 2024年第7期37卷 109-133页

作者： Jianfei WEI Silong ZHANG Jingying ZUO Xin LI Jiang QIN Wen BAO School of Energy science and Engineering Harbin Institute of TechnologyHarbin 150001China

Supersonic fuel film cooling is a promising way to simultaneously reduce the severe wall heat and friction load of the internal passage in a scramjet engine when operating at hypersonic *** eddy simulations were performed to investigate the cooling and wall friction characteristics of hydrogen and hydrocarbon films under inert and reactive *** results show that the essential difference of the turbulent state in the mixing layer contributes to the totally different behaviors of the cooling and wall friction reduction performances of the two fuel *** turbulent transport processes between the hydrogen film and the mainstream are much weaker as compared to the case of hydrocarbon film,making inert hydrogen rather superior in cooling and friction reduction ***,the increase of wall temperature for hydrogen film under the inert case is mainly driven by the loss of hydrogen with high heat capacity instead of by direct heat ***,the film cooling performance severely deteriorates when the hydrogen film burns due to presence of severe heat release sources near the *** the other hand,combustion of hydrocarbon film in the boundary layer can remarkably improve its originally barely-satisfactory cooling and friction reduction performance to the level comparable to that of hydrogen film,due to the suppression of turbulent transport processes in the mixing layer and presence of heat absorption sources near the ***,the hydrogen film is more advantageous in friction reduction,while the hydrocarbon film is more suitable for cooling.

关键词： Supersonic film cooling Hydrogen Hydrocarbon Boundary layer combustion Large eddy simulation

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Corrosion evaluation and resistance study of alloys in chloride salts for concentrating solar power plants

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Rare Metals 2024年第3期43卷 1222-1233页

作者： Dong-Mei Han Yong Shuai Bachirou Guene Lougou Bo-Xi Geng Xi-Bo He Tian-Tian Yan Jia-Meng Song School of Energy science and Engineering Harbin Institute of TechnologyHarbin150001China

Thermal energy storage(TES)systems based on molten salt are widely used in concentrating solar power(CSP)*** investigation of the corrosion behavior of alloy materials in molten salt is crucial for the correct selection of alloy materials and the design of TES *** this study,the corrosion behavior of 304,310S,316,and In625 alloys in molten chloride salts(27 mol%NaCl-22 mol%KCl-51 mol%MgCl,)was *** evolution of mass loss of the alloy samples with corrosion time and temperature and the analysis of the experimental results by scanning electron microscopy(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD)revealed the corrosion mechanism of the alloy samples in molten chloride *** main factors affecting the corrosion of the alloy samples were further *** was found that the loose multi-layer corrosion was formed on the surface of the corroded alloy samples with the increase in corrosion ***,the experimental *** that Mo played a positive role in improving the corrosion resistance of the alloy samples because the presence of Mo could inhibit the outward diffusion of alloying element *** work enriches the molten salt corrosion database and provides a reference for the selection of alloy materials for TES systems with potential application in CSP plants.

关键词： Thermal energy storage Molten chloride salt Alloy materials Corrosion mechanism Corrosion resistance

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Selective core-shell doping enabling high performance 4.6 V-LiCoO2

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Journal of Energy Chemistry 2024年第8期95卷 684-693页

作者： Yueming Xia Jianrui Feng Jinhui Li Yan Li Zhengfeng Zhang Xiaoqi Wang Jianli Shao Manling Sui Pengfei Yan Beijing Key Laboratory of Microstructure and Property of Solids College of Materials Science & Engineering Beijing University of Technology Petro China Research institute of Petroleum Exploration & Development State Key Laboratory of Explosion science and technology Beijing Institute of Technology

Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO2（LCO）.Herein,we manage to synthesize a surface Mg-doping and bulk Al-doping coreshell structured LCO,which demonstrates excellent cycling ***-cell shows 94.2% capacity retention after 100 cycles at 3.0-4.6 V（***/Li+） cycling,and no capacity decay after 300 cycles for fullcell test（3.0-4.55 V）.Based on comprehensive microanalysis and theoretical calculations,the degradation mechanisms and doping effects are systematically *** the undoped LCO,high voltage cycling induces severe interfacial and bulk degradations,where cracks,stripe defects,fatigue H2 phase,and spinel phase are identified in grain *** the doped LCO,Mg-doped surface shell can suppress the interfacial degradations,which not only stabilizes the surface structure by forming a thin rock-salt layer but also significantly improves the electronic conductivity,thus enabling superior rate *** Al-doping can suppress the lattice "breathing" effect and the detrimental H3 to H1-3 phase transition,which minimizes the internal strain and defects growth,maintaining the layered structure after prolonged *** theoretical calculations,this work deepens our understanding of the doping effects of Mg and Al,which is valuable in guiding the future material design of high voltage LCO.

关键词： Doping effect Electron microscopy Failure mechanism High-voltage LiCoO2 Lithium-ion battery

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Hybrid concurrency control protocol for data sharing among heterogeneous blockchains

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Frontiers of Computer science 2024年第3期18卷 1-12页

作者： Tiezheng GUO Zhiwei ZHANG Ye YUAN Xiaochun YANG Guoren WANG School of Computer science and technology Beijing Institute of TechnologyBeijing 100029China School of Computer science and Engineering Northeastern UniversityShenyang 110167China

With the development of information technology and cloud computing,data sharing has become an important part of scientific *** traditional data sharing,data is stored on a third-party storage platform,which causes the owner to lose control of the *** a result,there are issues of intentional data leakage and tampering by third parties,and the private information contained in the data may lead to more significant ***,data is frequently maintained on multiple storage platforms,posing significant hurdles in terms of enlisting multiple parties to engage in data sharing while maintaining *** this work,we propose a new architecture for applying blockchains to data sharing and achieve efficient and reliable data sharing among heterogeneous *** design a new data sharing transaction mechanism based on the system architecture to protect the security of the raw data and the processing *** also design and implement a hybrid concurrency control protocol to overcome issues caused by the large differences in blockchain performance in our system and to improve the success rate of data sharing *** took Ethereum and Hyperledger Fabric as examples to conduct crossblockchain data sharing *** results show that our system achieves data sharing across heterogeneous blockchains with reasonable performance and has high scalability.

关键词： data sharing blockchain concurrency control protocol crosschain

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Evaluation of neutron cross sections of^(48)Ti based on the Unified-Monte-Carlo-B method

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Chinese Physics C 2024年第7期48卷 118-130页

作者：夏候琼续瑞瑞刘萍 Roberto Capote 田源陶曦吴小飞张玥葛智刚舒能川冯松 China Nuclear data Center China Institute of Atomic EnergyBeijing 102413China NAPC–Nuclear data Section P.O.Box 100Vienna International CentreA-1400ViennaAustria School of Nuclear science and technology University of South ChinaHengyang 421001China

A cross section evaluation of neutron induced reactions on^(48)Ti is undertaken using the Unified Monte Carlo-B(UMC-B)*** evaluation concentrates on estimating the covariance and the use of the UMC-B allows avoiding the deficiencies of linear regression brought by the traditional least squares *** main neutron and charged particle emission reactions from n+^(48)Ti in the fast neutron energy region below 20 MeV are studied in this *** posterior probability density function(PDF)of each neutron cross section is obtained in a UMC-B Bayesian approach by convoluting the model PDFs sampled based on model parameters and the likelihood functions for the experimental *** model parameters including level density,pair corrections,optical model and Kalbach matrix element parameter are stochastically sampled with the assumption of normal distributions to estimate the model *** Cholesky factorization approach is applied to consider potential parameter ***,the posterior covariance matrices are generated using the UMC-B generated *** new evaluated results are compared with the CENDL-3.2,ENDF/B-VIII.0,JEFF-3.3,TENDL-2021 and JENDL-5 evaluations and differences are discussed.

关键词： covariance Unified Monte Carlo B(UMC-B) ^(48)Ti neutron cross sections Cholesky factor-ization approach

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Lath-like phases formed at an extremely high temperature in a Mg-RE(RE=rare earth)-Al alloy

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Rare Metals 2024年第8期43卷 3937-3945页

作者： Bo Deng Shu-Hui Lv Qiang Yang Dong-Yue Zhao Jun-Yuan Fan Xin Qiu School of Materials science and Engineering Changchun University of Science and Technology State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences Chongqing Research institute Changchun University of Science and Technology

Thermal stable intermetallic particles are important for the heat resistance of magnesium（Mg）*** this work,many lath-like particles formed in α-Mg grains of a Mg-8Gd-3Sm-0.7Al casting alloy when heat-treated at 873 ***-resolution high-angle annular dark field scanning transmission electron microscopy（HAADF-STEM） characterizations indicate that most of them are Mg-containing Al2（Gd,Sm）,with the atomic ratio of Mg:Al:（Gd,Sm） being ～1:1:1;a small part of them with relatively wider thickness are long-period stacking ordered（LPSO） phases simultaneously containing both 14H and 18R *** followed common orientation relationships with Mg matrix as those reported in previous *** addition,many Mg laths were observed in the primary blocky Al2（Gd,Sm） phase at grain boundaries,where the atomic ratio of Al:（Gd,Sm） in the Al2（Gd,Sm） matrix was 2:***,density functional theory（DFT） calculations illustrated the detail structure of the re-constructed Mg/Al2RE interface and simultaneously deduced the underlying reason for the re-dissolution of the newly formed Mg-containing Al2（Gd,Sm） plates in α-Mg matrix.

关键词： Magnesium alloy HAADF-STEM Microstructures Intermetallic particles Orientation relationships Interfaces

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