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Design of digital calibration based on variable step size of sub-binary SAR ADC

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The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 62-71页

作者： Liu Wei Zhao Yanke shang Shiguang School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

Addressing the impact of capacitor mismatch on the conversion accuracy of successive approximation register analog-to-digital converter(SAR ADC),a 12-bit 1 MS/s sub-binary SAR ADC designed using variable step size digital calibration was *** least mean square(LMS)calibration algorithm was employed with a ramp signal used as the calibration *** errors,extracted under injected disturbances,underwent iterative training to optimize weight *** address the trade-off between conversion accuracy and speed caused by a fixed step size,a novel variable step size algorithm tailored for SAR ADC calibration was *** core circuit and layout of the SAR ADC were implemented using the Taiwan Semiconductor Manufacturing Company(TSMC)0.35μm complementary metal-oxide-semiconductor(CMOS)commercial *** of the SAR ADC calibration algorithm was conducted using Simulink,demonstrating quick convergence and meeting conversion accuracy requirements compared to fixed step size *** results indicated that the convergence speed of the LMS digital calibration algorithm with variable step size was approximately eight times faster than that with a fixed step size,also yielding a lower mean square error(MSE).After calibration,the simulation results for the SAR ADC exhibited an effective number of bit(ENOB)of 11.79 bit and a signal-to-noise and distortion ratio(SNDR)of 72.72 dB,signifying a notable enhancement in the SAR ADC performance.

关键词： successive approximation register analog-to-digital converter(SAR ADC) variable step size digital calibration disturbance technique

Optimal Risk Sharing for Maxmin Choquet Expected Utility Model

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 430-444页

作者： De-jian TIAN shang-ri WU School of Mathematics China University of Mining and TechnologyXuzhou 221116China

This article analyzes the Pareto optimal allocations,agreeable trades and agreeable bets under the maxmin Choquet expected utility(MCEU)*** provide several useful characterizations for Pareto optimal allocations for risk averse *** derive the formulation descriptions for non-existence agreeable trades or agreeable bets for risk neutral *** build some relationships between ex-ante stage and interim stage on agreeable trades or bets when new information arrives.

关键词： maxmin Choquet expected utility model Pareto optimal allocation agreeable trade agreeable bet

Dynamic modeling and RBF neural network compensation control for space flexible manipulator with an underactuated hand

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Chinese Journal of Aeronautics 2024年第3期37卷 417-439页

作者： Dongyang shang Xiaopeng LI Meng YIN Fanjie LI School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

In space operation,flexible manipulators and gripper mechanisms have been widely used because of light weight and ***,the vibration caused by slender structures in manipulators and the parameter perturbation caused by the uncertainty derived from grasping mass variation cannot be *** existence of vibration and parameter perturbation makes the rotation control of flexible manipulators difficult,which seriously affects the operation accuracy of ***’s more,the complex dynamic coupling brings great challenges to the dynamics modeling and vibration *** solve this problem,this paper takes the space flexible manipulator with an underactuated hand(SFMUH)as the research *** dynamics model considering flexibility,multiple nonlinear elements and disturbance torque is established by the assumed modal method(AMM)and Hamilton’s principle.A dynamic modeling simplification method is proposed by analyzing the nonlinear ***’s more,a sliding mode control(SMC)method combined with the radial basis function(RBF)neural network compensation is ***,the control law is designed using a saturation function in the control method to weaken the chatter *** the help of neural networks to identify the uncertainty composition in the SFMUH,the tracking accuracy is *** results of ground control experiments verify the advantages of the control method for vibration suppression of the SFMUH.

关键词： Space flexible manipulator RBF neural network Underactuated hand Dynamic models Model simplification

Distributed Region Tracking and Perimeter Surveillance for Second-Order Multi-Agent Systems in Star-Shaped Sets

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Journal of Systems Science & Complexity 2024年第5期37卷 1995-2020页

作者： shang Juan MO Lipo MI Rongxin CAO Xianbing School of Mathematics and Statistics Beijing Technology and Business University The Department of Foundation Shijiazhuang Institute of Railway Technology School of Computer and Artificial Intelligence Beijing Technology and Business University Research Centre for Agri-Product Quality Traceability Beijing Technology and Business University Coordination Center of China National Computer Network Emergency Response Technical Team

This paper investigates region tracking and perimeter surveillance of second-order multi-agent systems, where all agents move within a star-shaped set. First, by coordination transformations,the region tracking problem is converted from the star-shaped sets to a circular region. The authors employ communication and collaboration to complete region tracking and perimeter surveillance tasks,and then revert back to the star-shaped set by using inverse transformations. Second, the authors propose a distributed control strategy based on attractive and interaction potential functions, under which all agents can quickly track a given circular region and move around the perimeter. Finally,the authors validate the effectiveness and performance advantages of the proposed method through simulation experiments.

关键词： Distributed control multi-agent systems star-shaped sets target tracking

Recent progress in visualization and digitization of coherent transformation structures and application in high-strength steel

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1298-1310页

作者： Xuelin Wang Zhenjia Xie Xiucheng Li Chengjia shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Yangjiang Branch Guangdong Laboratory for Materials Science and Technology(Yangjiang Advanced Alloys Laboratory)Yangjiang 529500China

High-strength steels are mainly composed of medium-or low-temperature microstructures,such as bainite or martensite,with coherent transformation *** type of microstructure has a high density of dislocations and fine crystallographic structural units,which ease the coordinated matching of high strength,toughness,and ***,given its excellent welding perform-ance,high-strength steel has been widely used in major engineering constructions,such as pipelines,ships,and ***,visual-ization and digitization of the effective units of these coherent transformation structures using traditional methods(optical microscopy and scanning electron microscopy)is difficult due to their complex ***,the establishment of quantitative relationships with macroscopic mechanical properties and key process parameters presents additional *** article reviews the latest progress in microstructural visualization and digitization of high-strength steel,with a focus on the application of crystallographic methods in the development of high-strength steel plates and *** obtained the crystallographic data(Euler angle)of the transformed microstruc-tures through electron back-scattering diffraction and combined them with the calculation of inverse transformation from bainite or martensite to austenite to determine the reconstruction of high-temperature parent austenite and orientation relationship(OR)during con-tinuous cooling ***,visualization of crystallographic packets,blocks,and variants based on actual OR and digit-ization of various grain boundaries can be effectively completed to establish quantitative relationships with alloy composition and key process parameters,thereby providing reverse design guidance for the development of high-strength steel.

关键词： high-strength steel microstructure visualization digitization quantification mechanical properties

石墨烯及其复合材料在催化有机反应中的研究新进展

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有机化学 2014年第8期34卷 1542-1548页

作者：张丽高书涛刘伟华唐然肖商宁昭王春王志河北农业大学理学院保定071001

石墨烯作为一种新型碳纳米材料,由于其具有大的比表面积、良好的热稳定性和化学稳定性、易于进行化学修饰等优点,基于石墨烯及其复合材料的催化体系得到了广泛的关注.目前石墨烯及其复合材料已经成功地应用于催化Suzuki-Miyaura,Heck,... 详细信息

石墨烯作为一种新型碳纳米材料,由于其具有大的比表面积、良好的热稳定性和化学稳定性、易于进行化学修饰等优点,基于石墨烯及其复合材料的催化体系得到了广泛的关注.目前石墨烯及其复合材料已经成功地应用于催化Suzuki-Miyaura,Heck,硝基还原,氨硼烷水解脱氢等一系列有机反应.对近年来石墨烯及其复合材料催化的有机反应的最新研究进展进行简要评述.

关键词：石墨烯有机合成催化综述

Energy harvesting technology for AC overhead insulated transmission line based on electric field induction

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High Voltage 2024年第4期9卷 816-825页

作者： Le Zhou Hongwei Liu Kun Zuo Kuo shang School of Electrical and Electronic Engineering North China Electric Power UniversityBeijingChina Electric Power Company of Sichuan Province Tianfu Power Supply Company ChengduSichuanChina Changde Power Supply Branch State Grid Hunan Electric Power Company LimitedChangdeHunanChina

To solve the problem of the energy harvesting(EEH)effect of the condition monitoring devices power supply on the transmission line is not *** authors designed three kinds of EEH schemes based on AC electric field induction,which can effectively improve the output power of load power *** EEH principle of each scheme was analysed in detail,and the influence factors such as the shape of outer energy harvester,capacitance compensation and impedance matching characteristics were ***,the experiment showed that 140.9 mW of power was obtained in direct-mode field EEH when the line voltage level was 10 *** high-potential field EEH mode obtained 4.1 mW of *** harvesting effect of the inner energy harvester with the same potential as the aluminium wire was obviously better,and 30.7 mW of power was ***,based on the third mode,when the load resistance was 2200Ω,the rectifier received 23.7 mW DC *** experimental results are in agreement with the theoretical analysis,which verifies the effectiveness of the electric field induction power supply technology.

关键词： field harvesting mode

Vibration suppression for rotating space slender flexible structures based on novel deformation description and NNSMC controller with hyperbolic tangent function

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Chinese Journal of Aeronautics 2024年第10期37卷 339-364页

作者： Dongyang shang Xiaopeng LI Men YIN Sainan ZHOU School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

Rotating Space Slender Flexible Structures(RSSFS)are extensively utilized in space operations because of their light weight,mobility,and low energy *** realize the accurate space operation of the RSSFS,it is necessary to establish a precise mechanical model and develop a control algorithm with high ***,with the application of traditional control strategies,the RSSFS often suffers from the chattering phenomenon,which will aggravate structure *** this paper,novel deformation description is put forward to balance modeling accuracy and computational efficiency of the RSSFS,which is better appropriate for real-time ***,the Neural Network Sliding Mode Control(NNSMC)strategy modified by the hyperbolic tangent(tanh)function is put forward to compensate for modeling errors and reduce the chattering phenomenon,thereby improving the trajectory tracking accuracy of the ***,a mathematical model for the RSSFS is developed according to the novel deformation description and the vibration theory of flexible *** of the deformation accuracy between different models proves that the novel modeling method proposed has high modeling ***,the universal approximation property of the Radial Basis Function(RBF)neural network is put forward to determine and compensate for modeling errors,which consist of higher-order modes and the uncertainties of external *** addition,the tanh function is proposed as the reaching law in the conventional NNSMC strategy to suppress driving torque *** control law of modified NNSMC strategy and the adaptive law of weight coefficients are developed according to the Lyapunov theorem to guarantee the RSSFS ***,the simulation and physical experimental tests of the RSSFS with different control strategies are *** results show that the control law according to the novel deformation description and the modified NNSMC strategy can obta

关键词： Space slender flexible structure Novel deformation description RBF neural network Vibration suppression Hyperbolic tangent function

Energy-Function Based Pilot Protection Scheme for Hybrid UHVDC Transmission Applying Improved Hausdorff Distance

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 891-902页

作者： Zijiang Wang Youping Fan Ben shang Yinbiao Shu School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China Institute of Next Generation Power Systems&International Standards Wuhan UniversityWuhan 430072China CSEE IEEE

A hybrid UHVDC transmission system applying LCC as the rectifier and MMC as the inverter combines the advantages of both converter types,which makes this protection scheme more complicated.A new pilot protection scheme for a three-terminal hybrid DC transmission system applying energy functions is *** energy function for LCC is applied to MMC to derive the energy level of the hybrid ***,an improved Hausdorff distance(IHD)algorithm is proposed to detect the difference in energy levels between the normal and fault *** abrupt change in energy level is characterized by IHD change *** points at which the IHD change rate exceeds the threshold at converter stations are applied to determine the fault line and to estimate the fault *** proposed protection scheme is then verified by a simulation model of the Wudongde±800 kV three-terminal hybrid UHVDC transmission *** appropriate sampling frequency is selected for a real-time calculation,and the threshold is selected considering the effect of *** show the proposed scheme can identify and trip fault lines quickly and effectively,even for a 600Ωgrounding *** waveshape similarity algorithms are compared and *** with existing protection schemes,the proposed scheme transmits less data to improve communication speed and reliability.

关键词： Energy function Hausdorff distance pilot protection UHVDC transmission