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Multi-modal fusion for robust hand gesture recognition based on heterogeneous networks

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Science China(Technological Sciences) 2023年第11期66卷 3219-3230页

作者： ZOU YongXiang CHENG Long han lijun LI ZhengWei School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

hand gesture recognition has become a vital subject in the fields of human-computer interaction and rehabilitation *** paper presents a multi-modal fusion for hand gesture recognition(MFHG)model,which uses two heterogeneous networks to extract and fuse the features of the vision-based motion signals and the surface electromyography(s EMG)signals,*** extract the features of the vision-based motion signals,a graph neural network,named the cumulation graph attention(CGAT)model,is first proposed to characterize the prior knowledge of motion coupling between finger *** CGAT model uses the cumulation mechanism to combine the early and late extracted features to improve motion-based hand gesture *** the s EMG signals,a time-frequency convolutional neural network model,named TF-CNN,is proposed to extract both the signals'time-domain and frequency-domain *** improve the performance of hand gesture recognition,the deep features from multiple modes are merged with an average layer,and then the regularization items containing center loss and the mutual information loss are employed to enhance the robustness of this multi-modal ***,a data set containing the multi-modal signals from seven subjects on different days is built to verify the performance of the multi-modal *** experimental results indicate that the MFHG can reach 99.96%and 92.46%accuracy on hand gesture recognition in the cases of within-session and cross-day,respectively.

关键词： leap motion s EMG multi-modal graph neural network hand gesture recognition

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Tensile strength behavior of cement-stabilized dredged sediment reinforced by polypropylene fiber

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Frontiers of Structural and Civil Engineering 2024年第3期18卷 380-392页

作者： Lei LANG Jiangshan LI Xin CHEN lijun han Ping WANG State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicChinese Academy of SciencesWuhan 430071China Hubei Provincial Key Laboratory of Contaminated Sludge and Soil Science and Engineering Wuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

This study evaluated the feasibility of using polypropylene fiber(PF)as reinforcement in improving tensile strength behavior of cement-stabilized dredged sediment(CDS).The effects of cement content,water content,PF content and length on the tensile strength and stress–strain behavioral evolutions were evaluated by conducting splitting tensile strength ***,the micro-mechanisms characterizing the tensile strength behavior inside PF-reinforced CDS(CPFDS)were clarified via analyzing macro failure and microstructure *** results indicate that the highest tensile strengths of 7,28,60,and 90 d CPFDS were reached at PF contents of 0.6%,1.0%,1.0%,and 1.0%,exhibiting values 5.96%,65.16%,34.10%,and 35.83%higher than those of CDS,***,3 mm,PF of showed the best reinforcement *** CPFDS exhibited obvious tensile strain-hardening characteristic,and also had better ductility than *** mix factor(C_(C)^(a)/C_(w)^(b))and time parameter(q_(t0)(t))of CDS,and the reinforcement index(k_(t-PF))of CPFDS were used to establish the tensile strength prediction models of CDS and CPFDS,considering multiple *** PF“bridge effect”and associated cementation-reinforcement coupling actions inside CPFDS were mainly responsible for tensile strength behavior *** key findings contribute to the use of CPFDS as recycled engineering soils.

关键词： dredged sediment chemical stabilization fiber reinforcement splitting tensile strength micro-mechanisms

Mechanical and damage evolution properties of sandstone under triaxial compression

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International Journal of Mining Science and Technology 2016年第4期26卷 601-607页

作者： Zong Yijiang han lijun Wei Jianjun Wen Shengyong State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology Xuzhou 221116 China Jiangsu Collaborative Innovation Center for Building Energy Saving and Construction Technology Jiangsu Jianzhu Institute Xuzhou 221116 China

To study the mechanical and damage evolution properties of sandstone under triaxial compression, we analyzed the stress strain curve characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression were split failure parallel to the axis of samples, while macroscopic failure forms under uniaxial compression were shear failure, the shear failure angle of which decreased linearly with confin- ing pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressures, and we analyzed the damage evolution properties of samples based on acoustic emission damage and volumetric dilatation damage, and established damage constitutive model, realizing the real-time Quantitative evaluation of samnles damage state in loading process.

关键词： Rock mechanics Mechanical properties Dilatation Damage evolution Failure characteristics

Development and application of novel high‐efficiency composite ultrafine cement grouts for roadway in fractured surrounding rocks

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Deep Underground Science and Engineering 2024年第1期3卷 53-69页

作者： Maolin Tian Shaojie Chen lijun han Hongtian Xiao Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation Shandong University of Science and TechnologyQingdaoChina College of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdaoChina College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdaoChina State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouChina

The fractured surrounding rocks of roadways pose major challenges to safe *** has often been used to reinforce the surrounding rocks to mitigate the safety risks associated with fractured *** aim of this study is to develop highly efficient composite ultrafine cement(CUC)grouts to reinforce the roadway in fractured surrounding *** materials used are ultrafine cement(UC),ultrafine fly ash(UF),ultrafine slag(US),and additives(superplasticizer[SUP],aluminate ultrafine expansion agent[AUA],gypsum,and retarder).The fluidity,bleeding,shrinkage,setting time,chemical composition,microstructure,degree of hydration,and mechanical property of grouting materials were evaluated in this ***,a suitable and effective CUC grout mixture was used to reinforce the roadway in the fractured surrounding *** results have shown that the addition of UF and US reduces the plastic viscosity of CUC,and the best fluidity can be obtained by adding 40%UF and 10%*** UC and UF particles are small,the pozzolanic effect of UF promotes the hydration reaction,which is conductive to the stability of CUC *** addition,fine particles of UC,UF,and US can effectively fill the pores,while the volumetric expansion of AUA and gypsum decreases the pores and thus affects the microstructure of the solidified *** compressive test results have shown that the addition of specific amounts of UF and US can ameliorate the mechanical properties of CUC ***,the CUC22‐8 grout was used to reinforce the No.20322 belt *** results of numerical simulation and field monitoring have indicated that grouting can efficaciously reinforce the surrounding rock of the *** this research,high‐performance CUC grouts were developed for surrounding rock reinforcement of underground engineering by utilizing UC and some additives.

关键词： broken surrounding rock composite ultrafine cement(CUC)grouts grouting material grouting performance grouting reinforcement

Adaptive nonsingular fast terminal sliding mode control for underwater manipulator robotics with asymmetric saturation actuators

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Control Theory and Technology 2020年第1期18卷 81-91页

作者： Zeng cheng ZHOU Guoyuan TANG Hui HUANG lijun han Ruikun XU School of Naval Architecture and Ocean Engineering Huazhong University of Science and TechnologyWuhan Hubei 430074China Collaborative Innovation Center for Advanced Ship and Deep-sea Exploration(CISSE) Wuhan Hubei 430074China

In this paper,an adaptive nonsingular fast terminal sliding mode control(ANFTSMC)is proposed for underwater manipulator robotics with asymmetric actuator saturations and unknown time-varying(TV)external ***,the nonsingular fast terminal sliding mode(NFTSM)control scheme is conducted for the underwater manipulator robotics,which guarantees the boundedness of all the signals in the control ***,the adaptive method and the smooth hyperbolic tangent(tanh)function are introduced to address the unknown TV external disturbances and the input saturation *** the prior knowledge about the upper bounds of the system uncertainties is not needed in this *** deal with the nonlinear asymmetric input saturation issue,a Gaussian error function is employed in the asymmetric saturation module so that the discontinuous input signals can be transformed into smooth ***,the rigorous mathematical verification is conducted to demonstrate the stability and finite-time convergence of the closed-loop control system via the Lyapunov ***,numerical simulations are performed on a two-link underwater manipulator robotic system to illustrate the effectiveness of the proposed controller.

关键词： Finite time stability sliding mode control asymmetric saturation underwater manipulator Gaussian error function

Mechanical properties and failure characteristics of fractured sandstone with grouting and anchorage

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International Journal of Mining Science and Technology 2014年第2期24卷 165-170页

作者： Zong Yijiang han lijun Qu Tao Yang Shengqi State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining & Technology Jiangsu Jianzhu Institute Shanxi Electric Power Exploration & Design Institute

Based on uniaxial compression experimental results on fractured sandstone with grouting and anchorage, we studied the strength and deformation properties, the failure model, crack formation and evolution laws of fractured sandstone under different conditions of anchorage. The experimental results show that the strength and elastic modulus of fractured sandstone with different fracture angles are significantly lower than those of intact sandstone. Compared with the fractured samples without anchorage,the peak strength, residual strength, peak and ultimate axial strain of fractured sandstone under different anchorage increase by 64.5–320.0%, 62.8–493.0%, and 31.6–181.4%, respectively. The number of bolts and degree of pre-stress has certain effects on the peak strength and failure model of fractured sandstone. The peak strength of fractured sandstone under different anchorage increases to some extent, and the failure model of fractured sandstone also transforms from tensile failure to tensile–shear mixed failure with the number of bolts. The pre-stress can restrain the formation and evolution process of tensile cracks, delay the failure process of fractured sandstone under anchorage and impel the transformation of failure model from brittle failure to plastic failure.

关键词： Fractured rock mass Anchorage properties Peak strength Crack propagation Failure characteristics

Simulation experiment on anti-penetration capability of anchored rock mass

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Mining Science and Technology 2011年第6期21卷 873-876页

作者： Xia Songlin Liu Hongwei han lijun XU Guoan State Key Laboratory of Geomechanics and Deep Underground Engineering China University of Mining ＆ Technology Xuzhou 221008 China Xuzhou Air Force Institute Xuzhou 221000 China

In order to solve the problem of experimental research on the penetration process of projectile into anchored rock mass, we derived the essential similarity conditions for the physical simulation experi- ment according to the similarity theory, carried out the experiment on the penetration process of a kind of penetrating bomb into the anchored rock mass of type III, and compared the experimental results with the values computed by the professional Young's empirical formula. The test results show that the phys- ical simulation experiment can represent the actual penetration process of projectile into anchored rock mass. The research method proposed in this paper provides technical support for the experimental research on the design and reconstruction of underground protection works.

关键词： Protection works Simulation experiment Penetration Anchored rock mass

Ringlike failure experiment of thick-walled limestone cylinder specimens in triaxial unloading tests

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Mining Science and Technology 2011年第3期21卷 445-450页

作者： Zhang Houquan He Yongnian Liu Honggang han lijun Shao Peng State Key Laboratory of Geomechanics and Deep Underground Engineering School of Mechanics and Civil Engineering China University of Mining ＆ TechnologyXuzhou 221008 China

In order to study the failure of surrounding rock under high in situ stress in deep underground engineering projects, disturbed by excavation unloading, we carried out triaxial unloading experiments using thickwalled cylinder specimens on a TATW-2000 rock servo-controlled triaxial testing machine in a laboratory. The specimens were made of limestone material, taken from Tongshan county, Xuzhou city, Jiangsu province, China. In our experiments, rock deformation and failure behavior was studied through loading and unloading of inner hole pressure of thick-walled cylinder specimens. At first, the axial stress, confining pressure and inner pressure were increased simultaneously to a specified designed state of stress. Then, keeping the axial stress and confining pressure stable, the pressure on the inner hole was decreased until the specimen was fractured. When the inner pressure was released completely but the specimen did not fracture, the confining pressure was decreased subsequently until complete failure occurred. Our experimental results suggest that traces of major circular ringlike fractures with a number of radial cracks often appear in thick cylinder walls. This type of ringlike failure phenomenon, similar to intermittent zonal fracturing characteristics of deep exploitation, has, so far, not been published. Our experimental results show that rock deformation and failure behavior of thick-walled limestone cylinders vary under different stress paths between loading and unloading. Tensile failure and orderly failure surfaces occur under unloading conditions while irregular damaged rock blocks are produced during loading failure. This type of triaxial unloading experiment provides for new research methodology and approach for thorough investigations on intermittent zonal fracturing in deep underground excavations.

关键词： Thick-walled cylinder specimens Triaxial tests Unloading Ringlike failure

Support technology for mine roadways in extreme weakly cemented strata and its application

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International Journal of Mining Science and Technology 2014年第2期24卷 157-164页

作者： Meng Qingbin han lijun Qiao Weiguo Lin Dengge Fan Jiadong State Key Laboratory of Geomechanics and Deep Underground Engineering China University of Mining & Technology College of Civil Engineering and Architecture Shandong University of Science and Technology

For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.

关键词： Extreme weakly cemented strata Mining gateway Support technology Numerical simulation with FLAC3D