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SSVEP-based brain-computer interfaces are vulnerable to square wave attacks

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Science China(Information Sciences) 2022年第4期65卷 80-92页

作者： rui BIAN Lubin meng Dongrui WU School of Artificial Intelligence and Automation Huazhong University of Science and Technology Zhejiang Lab

Electroencephalogram(EEG) based brain-computer interfaces(BCIs) have attracted wide attention in recent years. Steady-state visual evoked potential(SSVEP) is one of the most popular BCI paradigms,which has high information transmission rate and short user calibration time. Recent research has shown that EEG-based BCIs are under the threat of adversarial examples. However, existing attack approaches are very difficult to implement in a real-world system. Considering SSVEP’s dependency on the frequency information, this paper proposes to use square wave signals as adversarial perturbations to attack SSVEP-based BCIs, which are easy to generate and apply in practice. EEG trials contaminated by the square wave perturbation can be classified into any target class specified by the attacker. Compared with previous approaches,our perturbation can be implemented much more easily. Experiments on two SSVEP datasets demonstrated the efficiency and robustness of the proposed approach in attacking two SSVEP classifiers based on canonical correlation analysis, exposing a critical security problem in SSVEP-based BCIs.

关键词： electroencephalogram brain-computer interface steady-state visual evoked potential adversarial attack

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Adaptive Control for a Class of Nonlinear Time-Delay System Based on the Fully Actuated System Approaches

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Journal of Systems Science & Complexity 2022年第2期35卷 522-534页

作者： NING Pengju HUA Changchun meng rui School of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

This paper focuses on the problem of adaptive control for a class of time-delay ***,the strict feedback nonlinear time-delay system is transformed into a fully actuated system by utilizing the fully actuated system ***,the uncertain time-delay terms of the system are bounded by the product of the absolute value of the system state and the non-linear function with the unknown *** following the high order fully actuated system approaches,a continuous adaptive controller is designed for the *** is proved that the controller can render the system achieve asymptotically ***,two numerical examples are provided to illustrate the effectiveness of the theoretical results.

关键词： Adaptive control fully actuated system approaches nonlinear systems time-delay systems

Stress distribution and surrounding rock control of mining near to the overlying coal pillar in the working face

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International Journal of Mining Science and Technology 2019年第6期29卷 881-887页

作者： rui Gao Bin Yu Xiangbin meng Key Laboratory of Deep Coal Resource Mining School of MinesMinistry of Education of ChinaChina University of Mining&TechnologyXuzhou 221116China Datong Coal Mine Group Co.Ltd. Datong 037000China

The occurrence of overlying coal pillar(OCP)exerts a strong effect on the stress and strain distribution of the surrounding rock in the *** this paper,the stress distribution characteristics are analyzed via the numerical calculation with the account of OCP presence or *** addition,this study revealed the joint effect of side pressure relief area of the goaf and stress concentration in OCP on the final stress ***,the rules of abutment stress distribution affected by three influencing factors,namely horizontal-vertical distances between OCP and working face and buried depth of OCP,are *** functional model linking the peak stress of surrounding rock with the above influencing factors is *** field application of the above results proved that the rib spalling and deformation of a 2.95 m-high and 5.66 m-wide roadway could be efficiently controlled by rationally adjusting working states of the support,and adopting the hydraulic prop coordinated with the p type metal beam and anchor cable to strengthen the surrounding rock of working face and roadway,*** proposed measures are considered appropriate to satisfy the safe operation requirements.

关键词： Overlying coal pillar(OCP) Stress distribution Influencing factors Surrounding rock control

An M-Objective Penalty Function Algorithm Under Big Penalty Parameters

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Journal of Systems Science & Complexity 2016年第2期29卷 455-471页

作者： ZHENG Ying meng Zhiqing SHEN rui Basic College Ningbo Dahongying University College of Economics and Management Zhejiang University of Technology

Some classical penalty function algorithms may not always be convergent under big penalty parameters in Matlab software,which makes them impossible to find out an optimal solution to constrained optimization *** this paper,a novel penalty function(called M-objective penalty function) with one penalty parameter added to both objective and constrained functions of inequality constrained optimization problems is *** on the M-objective penalty function,an algorithm is developed to solve an optimal solution to the inequality constrained optimization problems,with its convergence proved under some ***,numerical results show that the proposed algorithm has a much better convergence than the classical penalty function algorithms under big penalty parameters,and is efficient in choosing a penalty parameter in a large range in Matlab software.

关键词： Algorithm constrained optimization problem M-objective penalty function stability.

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： rui Zhang Qi meng Zhi-Ming Ma Academy of Mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Recent progress in Li-ion batteries with TiO_(2) nanotube anodes grown by electrochemical anodization

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Rare Metals 2021年第2期40卷 249-271页

作者： meng-meng Zhang Jia-Yuan Chen Hui Li Chun-rui Wang College of Science and Shanghai Institute of Intelligent Electronics and Systems Donghua UniversityShanghai201620China

Self-organized titanium dioxide(TiO_(2))nanotubes,which are prepared by electrochemical anodizing,have been widely researched as promising anodes for Liion *** nanotubular morphology and bulk structure of TiO_(2)nanotubes can be easily changed by adjusting the anodizing and annealing *** is provided to investigate different phenomena by selectively adjusting a specific parameter of the Li^(+)insertion *** this paper,we reviewed how the morphology and crystallography of TiO_(2)nano tubes influence the electrochemical performance of Li^(+)*** particular,electrochemical performances of amorphous and anatase titanium dioxide nanotube anodes were compared in *** we all know,TiO_(2)nanotube anodes have the advantages of nontoxicity,good stability,high safety and large specific surface area,in lithium-ion ***,they suffer from poor electronic conductivity,inferior ion diffusivity and low theoretical capacity(335 mAh·g^(-1)),which limit their practical ***,there are two ways to overcome the shortcomings of titanium dioxide nanotube anodes,including doping and synthesis *** achievements and existing problems associated with doped TiO_(2)nanotube anodes and composite material anodes are summarized in the present *** on the analysis of lithium insertion mechanism of titanium dioxide nanotube electrodes,the prospects and possible research directions of TiO_(2)anodes in lithiumion batteries are discussed.

关键词： Electrochemical anodization TiO_(2)nanotubes Anodes Li-ion batteries

Simplified design of nonlinear damper parameters and seismic responses for long-span cable-stayed bridges with nonlinear viscous dampers

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1103-1116页

作者： Huihui LI Lifeng LI rui HU meng YE College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering Shenzhen UniversityShenzhen 518060China College of Civil Engineering Hunan UniversityChangsha 410082China

Viscous dampers are widely used as passive energy dissipation devices for long-span cable-stayed bridges for mitigation of seismic load-induced ***,complicated finite element(FE)modeling,together with repetitive and computationally intensive nonlinear time-history analyses(NTHAs)are generally required in conventional design *** streamline the preliminary design process,this paper developed a simplified longitudinal double degree of freedom model(DDFM)for single and symmetric twin-tower cable-stayed *** on the proposed simplified longitudinal DDFM,the analytical equations for the relevant mass-and stiffness-related parameters and longitudinal natural frequencies of the structure were derived by using analytical and energy *** of the relationship between the nonlinear viscous damper parameters and the equivalent damping ratio was achieved through the equivalent linearization ***,the analytical equations of longitudinal seismic responses for long-span cable-stayed bridges with nonlinear viscous dampers were *** on the developed simplified DDFM and suggested analytical equations,this paper proposed a simplified calculation framework to achieve a simplified design method of nonlinear viscous damper ***,the effectiveness and applicability of the developed simplified longitudinal DDFM and the proposed calculation framework were further validated through numerical analysis of a practical cable-stayed ***,the results indicated the following.1)For the obtained fundamental period and longitudinal stiffness,the differences between results of the simplified longitudinal DDFM and numerical analysis were only 2.05%and 1.5%,respectively.2)Relative calculation errors of the longitudinal girder-end displacement and bending moment of the bottom tower section of the bridge obtained from the simplified longitudinal DDFM were limited to less than 25%.3)The equivalent damping ratio of nonline

关键词： cable-stayed bridges viscous dampers simplified analytical model equivalent damping ratio seismic mitigation

Online asymmetry estimation for whole angle mode coriolis vibratory gyroscopes by high frequency injection

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Defence Technology（防务技术） 2023年第6期24卷 314-325页

作者： Xiang-rui meng Chong Li Yu-chen Wang Department of Automation and Measurement Ocean University of ChinaQingdao266000China

The whole angle mode gyroscope(WAMG)is considered to be the next generation architecture,but it is suffered from the asymmetry errors to conduct real *** paper proposes a novel high frequency injection based approach for the error parameters online identification for the *** significance is that it can separate physical and error fingerprints to enable online *** nonlinear WAMG dynamics are discretized to meet the requirement of numerical precision and computation *** optimized estimation methods are then constructed and compared to track asymmetry error parameters *** the validation part,its results firstly prove that the proposed scheme can accurately identify constant asymmetry parameters with an overall tracking error of less than 1 ppm and the extreme numerical convergence can reach 10^(-12)*** the dynamic asymmetry variation condition,the root mean square errors(RMSE)indicate that the tracking accuracy can reach the level of10^(-3),which shows the robustness of the proposed *** summary,the proposed method can effectively estimate the WAMG asymmetry errors online with satisfied performance and practical values.

关键词： Rate-integrating gyroscope(RIG) Whole angle mode gyroscope(WAMG) Coriolis vibrating gyroscope(CVG) Online calibration Online identification Online estimation

A deterministic FE contact analysis of 3D rough surfaces with textures and comparison with classic statistical contact models

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Science China(Technological Sciences) 2021年第2期64卷 297-316页

作者： ZHANG rui meng XiangHui LYU BuGao SUN Kai School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China AECC Commercial Aircraft Engine Company Limited Shanghai 200241China

Accurate contact calculations of real rough surfaces are fundamental but complicated. The model-based methods are convenient and straightforward. But these methods ignore some factors and may lead to less accurate results. This is especially true when considering multi-scale topographic features of engineering rough surfaces. Based on artificially generated rough surfaces, the deterministic contact analysis of two 3D rough surfaces is conducted by the finite element method(FEM). The calculations show that when the separation between surfaces reduces, results of classic model-based methods are quite different from those of this study, especially when the roughness distribution and textures are considered. As friction pairs are working under increasing harsh conditions, the accurate contact calculation in this paper will be of great significance.

关键词： deterministic contact analysis multi-scale topography finite element method(FEM) engineering rough surfaces