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Cancellation of nonlinear distortion based on integration of FCM clustering algorithm and adaptive-two-stage linear approximation

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The Journal of China Universities of Posts and Telecommunications 2014年第3期21卷 18-22页

作者： WANG Gui-ye zou wei-xia WANG Zhen-yu DU Guang-long GAO Ying Key laboratory of wireless universal communications Beijing University of Posts and Telecommunications School of Electronic Engineering Beijing University of Posts and Telecommunications

A hybrid system of the fuzzy c-means （FCM） clustering algorithm and adaptive-two-stage linear approximation was presented for nonlinear distortion cancellation of radio frequency （RF） power amplifier （PA）. This mechanism can effectively eliminate noise, adaptively model PA＇s instantaneous change, and efficiently correct nonlinear distortion. This article puts forward the FCM clustering algorithm for clustering received signals to eliminate white noise, and then uses the adaptive-two-stage linear approximation to fit the inverse function of the amplitude＇s and phase＇s nonlinear mapping during the training phase. Parameters of the linear function and similarity function are trained using the gradient-descent and minimum mean-square error criteria. The proposed approach＇s training results is directly employed to eliminate sampling signal＇s nonlinear distortion. This hybrid method is realized easier than the multi-segment linear approximation and could reduce the received signal＇s bit error rate （BER） more efficiently.

关键词： PA nonlinear distortion cancellation FCM clustering algorithm similarity function adaptive-two-stage linear approximation

Investigation of wake-induced vibration interference between two staggered wave-cone cylinders at subcritical Reynolds number

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Journal of Hydrodynamics 2024年第2期36卷 378-393页

作者： Lin zou Di-wei Liu Jian Liu Hong-cheng Zuo Yin-huan Zheng Hao xia School of Mechanical and Electronic Engineering Wuhan University of TechnologyWuhan430070China Department of Aeronautical and Automotive Engineering Loughborough UniversityLoughboroughUK

The wake induced vibration(WIV)of a one-and two-degree-of-freedom(1DOF,2DOF)downstream wave-cone cylinder(WCC)behind a stationary equal-size upstream wave-cone cylinder in the staggered arrangement is numerically investigated at subcritical Reynolds number of 3900 by using shear stressed transfer(SST)k-ωturbulence *** streamwise pitch ratios(P/Dm)vary from 4 to 6 with a fixed incident angleα=8°.Experimental measurements were also performed for the validation of the present numerical *** is found that the largest vibration amplitude in crossflow direction occurred at P/Dm=4,Ur=8 with small difference of streamwise vibration at P/Dm=4,*** from single wavy-cone cylinder(SWCC),the downstream flexible one of a pair staggered WCCs got larger vibration amplitude during phase switching stage instead of in-phase *** upstream wake will suppress the triple frequency of main frequency in the power spectra density(PSD)functions of Cl but stimulate the double one of *** intriguing vibration mechanism happened in all 2DOF cases where the trajectory of downstream WCC is a significant ellipse rather than a figure of *** transformation of phase switching and the variation of the main frequency of drag coefficient(Cd)can be explained by the vortex-shedding modes of downstream WCC.

关键词： Two wave-cone cylinders staggered arrangement wake induced vibration phase switching vortex shedding

Model-driven full system dynamics estimation of PMSM-driven chain shell magazine

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Defence Technology（防务技术） 2024年第9期39卷 147-156页

作者： Kai wei Longmiao Chen Quan zou School of Mechanical Engineering NanJing University of Science and TechnologyNanjing210094China

Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive extended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge exponentially to zero, and the parameter estimation error can be obtained from the extended state. Then, based on the extended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and excitation signal. Under persistent excitation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the extended state. Simulation and experimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.

关键词： Chain shell magazine Full system dynamics estimation Disturbance estimation Parameter estimation Adaptive extended state observer

Nearly degenerate ground states of a checkerboard antiferromagnet and their bosonic interpretation

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 84-89页

作者： Haiyuan zou Fan Yang wei Ku Key Laboratory of Polar Materials and Devices(MOE) School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200241China Department of Physics Beijing Institute of TechnologyBeijing 100081China Tsung-Dao Lee Institute Shanghai 200240China Key Laboratory of Artificial Structures and Quantum Control(Ministry of Education) Shanghai 200240China Shanghai Branch Hefei National LaboratoryShanghai 201315China

The spin-1/2 model system with antiferromagnetic(AF) couplings on a J1-J2checkerboard lattice, known as the planar pyrochlore model, is strongly frustrated and associated with a two-to-one dimensional crossover. Using the Projected Entangled Simplex States tensor network ansatz, we identify a large number of nearly degenerate states in the frustrated region(J_(1)

关键词： tensor networks frustrated magnetism dimensional crossover degenerate states

Design and experiment of anti-adhesion rototiller based on staggered double-roller scraping

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International Journal of Agricultural and Biological Engineering 2024年第4期17卷 165-175页

作者： Jian Cheng Junfang xia Kan Zheng Guoyang Liu Youshuai wei Juan zou College of Engineering Huazhong Agricultural UniversityWuhan 430070China Key Laboratory of Agricultural Equipment in Mid-lower Reaches of Yangtze River Ministry of Agriculture and Rural AffairsWuhan 430070China Hubei academy of agricultural sciences institute of food crops Wuhan 430070China

In order to solve the serious problem of soil adhering blade roller in the middle and lower reaches of Yangtze River,the anti-adhesion rototiller based on staggered double-roller scraping(ARSDS)was designed by mechanical scraping *** volume equation for scraping the soil adhesion part with staggered rotary blades was *** mechanical conditions for separation of soil adhesion part from blade roller were clarified,and the contact time between rotary blade and soil during rotary tillage was *** this way,the key parameters affecting soil adhering on and separating from the blade roller were determined,which were rotational speed,cutting pitch and tillage *** spatial and temporal trajectory changes for the sidelong section edge of staggered rotary blades were analyzed,so that the rotary blade arrangement was *** the discrete element method,selecting the soil adhesion mass on the staggered blade rollers as the response value established prediction model by Box-Behnken design *** example,taking the tillage depth of 14 cm for wheat cultivation in the middle and lower reaches of Yangtze River,the optimal combination of parameters was determined to be 230 r/min and 10 cm for rotational speed and cutting pitch,*** this time,the soil adhesion mass was 4566.67 *** the meantime,the process of soil particles adhering staggered blade rollers and rotary blades scraping off the adhering soil were *** experiments have shown that the operation quality of ARSDS met the requirements of rototiller performance *** the rice stubble field of high water moisture,the soil adhesion mass was 13.455 kg and 38.215 kg for ARSDS and conventional rototiller,respectively,which indicated that ARSDS effectively reducing soil adhesion *** research results can provide technical support for the design of rototiller reducing soil adhesion in the agricultural areas of the middle and lower reaches of the Yangtze River.

关键词： rice stubble field rotary tillage reducing soil adhesion staggered double-roller discrete element method

Distributed Predefined-Time Control for Cooperative Tracking of Multiple Quadrotor UAVs

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2179-2181页

作者： Kewei xia Xinyi Li Kaidan Li Yao zou Advanced Research Institute of Multidisciplinary Sciences Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China the School of Automation Beijing Institute of TechnologyBeijing 100081China the School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China the Key Laboratory of Intelligent Bionic Unmanned Systems Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

Dear Editor,This letter addresses the predefined-time control for cooperative tracking of multiple quadrotor unmanned aerial vehicles(UAVs)under a directed communication network.A predefined-time distributed estimator... 详细信息

关键词： acceleration letter estimator

Numerical and theoretical study of large-scale failure of strata overlying sublevel caving mines with steeply dipping discontinuities

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1799-1815页

作者： Kaizong xia Zhiwei Si Congxin Chen xiaoshuang Li Junpeng zou Jiahao Yuan State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China School of Urban Construction Changzhou UniversityChangzhou 213164China Faculty of Engineering China University of Geosciences(Wuhan)Wuhan 430074China

The deformation and fracture evolution mechanisms of the strata overlying mines mined using sublevel caving were studied via numerical ***,an expression for the normal force acting on the side face of a steeply dipping superimposed cantilever beam in the surrounding rock was deduced based on limit equilibrium *** results show the following:(1)surface displacement above metal mines with steeply dipping discontinuities shows significant step characteristics,and(2)the behavior of the strata as they fail exhibits superimposition ***,failure first occurs in certain superimposed strata slightly far from the ***,with the constant downward excavation of the orebody,the superimposed strata become damaged both upwards away from and downwards toward the *** process continues until the deep part of the steeply dipping superimposed strata forms a large-scale deep fracture plane that connects with the *** deep fracture plane generally makes an angle of 12°-20°with the normal to the steeply dipping *** effect of the constant outward transfer of strata movement due to the constant outward failure of the superimposed strata in the metal mines with steeply dipping discontinuities causes the scope of the strata movement in these mines to be larger than *** strata in the metal mines with steeply dipping discontinuities mainly show flexural toppling ***,the steeply dipping structural strata near the goaf mainly exhibit shear slipping failure,in which case the mechanical model used to describe them can be simplified by treating them as steeply dipping superimposed cantilever *** taking the steeply dipping superimposed cantilever beam that first experiences failure as the key stratum,the failure scope of the strata(and criteria for the stability of metal mines with steeply dipping discontinuities mined using sublevel caving)can be obtained via iterative computations from the ke

关键词： sublevel caving mines universal distinct element code(UDEC)numerical approach large-scale ground movement steeply dipping superimposed cantilever beam toppling failure

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认知无线电中的动态频率选择和功率控制研究

系统仿真学报 2008年第7期20卷 1821-1825页

作者：邱晶邹卫霞重庆大学通信工程学院重庆400044 北京邮电大学电信工程学院北京100876

采用博弈理论对认知无线电网络中的分布式动态频率选择和功率分配策略进行建模分析,通过建立合作来协调认知节点间的行为,从而提高分布式决策算法的性能,并建立了一个模块化的通用仿真平台。仿真结果表明,该分布式算法能够以较快的速度... 详细信息

采用博弈理论对认知无线电网络中的分布式动态频率选择和功率分配策略进行建模分析,通过建立合作来协调认知节点间的行为,从而提高分布式决策算法的性能,并建立了一个模块化的通用仿真平台。仿真结果表明,该分布式算法能够以较快的速度收敛于系统稳定状态,且复杂度低、实现简单。

关键词：认知无线电分布式动态频率选择功率控制博弈论

A regularization algorithm of dynamic light scattering for estimating the particle size distribution of dual-substance mixture in water

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Particuology 2024年第6期89卷 246-257页

作者： Yanghong Wang Ziqiang Meng Zipei Zhang Min xia Li xia wei Li School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China

Dynamic light scattering(DLS)is a nondestructive,well-established technique for the size characterization of proteins,nanoparticles,polymers,and colloidal ***,current DLS techniques are only applied to particle groups of single composition due to the limitation of their inversion *** this study,we propose a particle size distribution inversion algorithm based on the Tikhnonov regularization method that can be applied to the dual-substance particle *** algorithm retrieves the particle size distributions of two substances,respectively,by taking advantage of their refractive index *** simulation results reveal that the algorithm has excellent accuracy and stability when the scattering angle is 30°.Instead of the original identity matrix,the first-order difference matrix and second-order difference matrix are used as the regular matrix when utilizing the Tikhnonov algorithm,which obviously improves the anti-interference,accuracy,and stability of the ***,the inversion of particle size distribution is carried out at a 0.01%–1%noise level,which shows that the algorithm has an available antinoise ***,experimental particle size measurements for a mixture of polystyrene beads and toner particles demonstrate that the proposed algorithm is superior to the traditional Tikhnonov algorithm in applicability and accuracy.

关键词： Dynamic light scattering Dual-substance mixture Particle sized istribution Tikhnonov regularization