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Graphic Processing Unit-Accelerated Mutual Information-Based 3D Image Rigid Registration

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Transactions of Tianjin University 2009年第5期15卷 375-380页

作者：李冠华欧宗瑛苏铁明韩军 Key laboratory for precision and Non-Traditional Machining Technology of Ministry of Education Dalian University of Technology Dalian Modern High-Tech Development Co.Ltd.

Mutual information(MI)-based image registration is effective in registering medical images,but it is computationally *** paper accelerates MI-based image registration by dividing computation of mutual information into spatial transformation and histogram-based calculation,and performing 3D spatial transformation and trilinear interpolation on graphic processing unit(GPU) .The 3D floating image is downloaded to GPU as flat 3D texture,and then fetched and interpolated for each new voxel location in fragment *** transformed re-sults are rendered to textures by using frame buffer object(FBO) extension,and then read to the main memory used for the remaining computation on *** results show that GPU-accelerated method can achieve speedup about an order of magnitude with better registration result compared with the software implementation on a single-core CPU.

关键词：图形处理单元三维图像注册登记加速比互信息基础刚性线性插值

Application of Ultrasonic Motor to Control of Moment Gyroscope Gimbal Servo System

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第1期34卷 15-21页

作者： Wu Jintao Pan Song Zhao Lei Wu Dengyun Zhang Jiyang Beijing Institute of Control Engineering Beijing 100190P.R.China precision Driving laboratory Nanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Attitude control system is one of the most important subsystems in a *** a key actuator,the control moment gyroscope(CMG)mainly determines the performance of attitude control ***,the control accuracy and output torque smoothness of the CMG depends more on its gimbal servo *** the constraints of size,mass and power consumption for a small satellite,here,a mini-CMG is designed,in which the gimbal servo system is driven by an ultrasonic *** good performances of the CMG are obtained by both the ultrasonic motor and the rotary *** direct drive of gimbal improves its dynamic performance,with the output bandwidth above 20 *** angular and speed closed-loop control obtains the 0.02°/s gimbal rate,and the output torque resolution better than 2×10^(-3) N·*** ultrasonic motor provides 1.0N·m self-lock torque during power-off,with 12arc-second position accuracy.

关键词： control moment gyroscope gimbal servo system ultrasonic motor

Investigation on Normal Dynamic Contact Characteristics of Mechanical Interface of Machine Tools

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Acta Mechanica Solida Sinica 2021年第1期34卷 104-123页

作者： Zhiqiang Gao Weiping Fu Wen Wang Shuangqi Wang Dongya Zhang Zhifei Xue School of Mechanical and precision Instrument Engineering Xian University of TechnologyXi’an710048China State Key laboratory of Power System of Tractor China YITUO Group Co.LtdLuoyang471039China

The dynamic contact characteristics of mechanical interface significantly impact the performance of machine *** static contact behaviors of mechanical interface have been ***,most mechanical interfaces are exposed to dynamic *** is necessary to study the dynamic contact characteristics of mechanical interface.A normal dynamic microcosmic contact model is built using the statistical method,and the interactional effects of adjacent asperities are *** influences of the normal preload,vibrational frequency and displacement amplitude on normal contact stiffness and damping of mechanical interface are *** predicted contact stiffness and damping of mechanical interface are verified by a series of simulations and experiments.

关键词： Dynamic Stiffness Damping Asperity interaction Experiment

A versatile electrostatic trap with open optical access

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Frontiers of physics 2018年第2期13卷 51-57页

作者：李胜强印建平 School of New Energy and Electronic Engineering Yancheng Teachers University Yancheng 224007 China State Key laboratory of precision Spectroscopy East China Normal University Shanghai 200062 China

A versatile electrostatic trap with open optical access for cold polar molecules in weak-field-seeking state is proposed in this paper. The trap is composed of a pair of disk electrodes and a hexapole. With the help of a finite element software, the spatial distribution of the electrostatic field is calculated. The results indicate that a three-dimensional closed electrostatic trap is formed. Taking NDa molecules as an example, the dynamic process of loading and trapping is simulated. The results show that when the velocity of the molecular beam is 10 m/s and the loading time is 0.9964 ms, the maximum loading efficiency reaches 94.25% and the temperature of the trapped molecules reaches about 30.3 inK. A single well can be split into two wells, which is of significant importance to the precision measurement and interference of matter waves. This scheme, in addition, can be further miniaturized to construct one-dimensional, two-dimensional, and three-dimensional spatial electrostatic lattices.

关键词： atomic and molecular physics electrostatic trap cold polar molecules finite elementanalysis

MODELING, VALIDATION AND OPTIMAL DESIGN OF THE CLAMPING FORCE CONTROL VALVE USED IN CONTINUOUSLY VARIABLE TRANSMISSION

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Chinese Journal of Mechanical Engineering 2008年第4期21卷 51-55页

作者： ZHOU Yunshan LIU Jin＇gang CAIYuanchun ZOU Naiwei State Key laboratory of Advanced Design and manufacturing for Vehicle Body Hunan University Changsha 410082 China College of Automotive Engineering Jilin University Changchun 130022 China

Associated dynamic performance of the clamping force control valve used in continuously variable transmission （CVT） is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm （GA） with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece.

关键词： Dynamic modeling Optimal design Genetic algorithm Clamping force control valve Continuously variable transmission (CVT)

Stochastic Resonance in a Single-Ion Nonlinear Mechanical Oscillator

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Chinese Physics Letters 2023年第8期40卷 11-14页

作者：崔太豪李冀袁泉魏雅琪戴双晴李沛东周飞张建奇陈亮冯芒 State Key laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsInnovation Academy of Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China Research Center for Quantum precision Measurement Guangzhou Institute of Industry TechnologyGuangzhou 511458China laboratory of Quantum Science and Engineering South China University of TechnologyGuangzhou 510641China Department of Physics Zhejiang Normal UniversityJinhua 321004China

Stochastic resonance is a counterintuitive phenomenon amplifying the weak periodic signal by application of external *** demonstrate the enhancement of a weak periodic signal by stochastic resonance in a trappedion oscillator when the oscillator is excited to the nonlinear regime and subject to an appropriate *** the full control of the radio-frequency drive voltage,this amplification originates from the nonlinearity due to asymmetry of the trapping potential,which can be described by a forced Duffing oscillator *** scheme and results provide an interesting possibility to make use of controllable nonlinearity in the trapped ion,and pave the way toward a practical atomic sensor for sensitively detecting weak periodic signals from real noisy environment.

关键词： oscillator nonlinearity periodic

Precise laser welding of austenitic stainless steel

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中国有色金属学会会刊：英文版 2005年第S3期15卷 353-358页

作者：杨家林黄文荣 Institute of Machinery manufacturing Technology China Academy of Engineering Physics Mianyang 621900 ChinaState Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China) Institute of Machinery manufacturing Technology China Academy of Engineering Physics Mianyang 621900 China

The welding parameters and quality of 0Cr18Ni9 austenitic stainless steel via laser penetrate welding were investigated, which was aimed to realize its precise laser welding with weld depth more than 2.5mm and weld deformation as small as possible. The welding parameters mainly include energy parameters (laser power and welding velocity), light factors (focus offset, beam offset and method to focus) and environment factors (type and flux of protecting gas). The test results demonstrate that the energy parameters have crucial effect on weld depth, which nearly increase linearly with the increase of laser power or the decrease of weld velocity, the light factors have certain effect on the wed depth, specially, which decreases obviously when beam offset exceeds 0.45mm. The tempe- rature increment at the position of 5mm away from weld centerline is less than 100℃ and the weld deformation is the axial shrinkage with depth less than 0.1mm.

关键词： precise laser welding weld deformation temperature rise

Effective medium theory applied to frequency selective surfaces on periodic substrates

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Chinese Optics Letters 2010年第12期8卷 1175-1177页

作者：朱华新高劲松赵晶丽王彤彤冯晓国梁凤超王岩松陈新 Key laboratory of Optical System Advanced manufacturing Technology Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

We apply the effective medium theory combined with the conventional periodic method of moments （MoM） to analyze frequency selective surfaces （FSSs） on periodic and anisotropic substrates. Based on the effective medium theory, even periodic and anisotropic substrates can be considered homogeneous; thus, the Green’s function can be obtained. The resulting integral equation can then be solved by the MoM using rooftop basis functions and Galerkin testing functions. We analyze an example using this technique, and the numerical results agree with Fallahi’s full-vector semi-analytical method, showing an increasing difference between the results as the frequencies increase. These results show that the proposed method is effective for analyzing FSSs on periodic and anisotropic substrates.

关键词： Anisotropic media Anisotropy Method of moments Numerical methods Substrates

Shear instability in heterogeneous nanolayered Cu/Zr composites

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Journal of Materials Science & Technology 2022年第10期105卷 81-91页

作者： Jianjun Li Feng Qin Dingshun Yan Wenjun Lu Jiahao Yao School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key laboratory of High Performance Complex manufacturing Central South UniversityChangsha 410083China School of Materials Science and Engineering Central South UniversityChangsha 410083China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

Ultrastrong nanolayered metallic composites are usually subjected to low ductility due to plastic instability during *** we investigated the shear instability of a newly designed heterogeneous nanolayered Cu/Zr composites by *** heterogeneity in size was generated by inserting a few thin Cu-Zr bilayers with an individual layer thickness of 2.5-10 nm into the interface region of the Cu/Zr layered composites with an individual layer thickness of 100 *** microindentation tests showed that multiple shear bands appeared in the heterogeneous composite with one bilayer,whereas only a single shear band was formed in that with two or three *** importantly,the layer strain in the multi-shear band region is much smaller than that in the single-shear band *** example,the strain of the 100 nm layers within the shear band in the composite with one 10 nm bilayer could reach as low as 2.8,which was less than half of that in the composite with three 10 nm bilayers,i.e.,*** fndings demonstrated that strain delocalization can be achieved through shear band multiplication if an appropriate number of thin bilayers were used as interlayers in the 100 nm Cu/Zr ***,compared with the homogeneous composite with an individual layer thickness of 100 nm and the bimodal composite which is composed of alternating one 100 nm Cu-Zr bilayer and two 10 nm CuZr bilayers,the heterogeneous composite with one bilayer displayed a higher strength(2.15 GPa)and a favorable resistance to strain localization.

关键词： Nanolayered metallic composites Sputtering Microindentation Shear band Strain delocalization