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Gaussian particle filter based pose and motion estimation

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第10期8卷 1604-1613页

作者： wu Xue-dong SONG Zhi-huan State Key Lab. of Industrial Control Technology Institute of Industrial Process Control Zhejiang University Hangzhou 310027 China Department of Electronic Information and Electrical Engineering Fujian University of Technology Fuzhou 350014 China

Determination of relative three-dimensional （3D） position, orientation, and relative motion between two reference frames is an important problem in robotic guidance, manipulation, and assembly as well as in other fields such as photogrammetry. A solution to pose and motion estimation problem that uses two-dimensional （2D） intensity images from a single camera is desirable for real-time applications. The difficulty in performing this measurement is that the process of projecting 3D object features to 2D images is a nonlinear transformation. In this paper, the 3D transformation is modeled as a nonlinear stochastic system with the state estimation providing six degrees-of-freedom motion and position values, using line features in image plane as measuring inputs and dual quaternion to represent both rotation and translation in a unified notation. A filtering method called the Gaussian particle filter （GPF） based on the panicle filtering concept is presented for 3D pose and motion estimation of a moving target from monocular image sequences. The method has been implemented with simulated data, and simulation results are provided along with comparisons to the extended Kalman filter （EKF） and the unscented Kalman filter （UKF） to show the relative advantages of the GPF. Simulation results showed that GPF is a superior alternative to EKF and UKF.

关键词： Gaussian particle filter (GPF) Pose and motion estimation Line features Monocular vision Extended Kalman filter(EKF) Unscented Kalman filter (UKF) Dual quatemion

Numerical investigation of the mechanical behavior of the backfill–rock composite structure under triaxial compression

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International Journal of Minerals,Metallurgy and Materials 2023年第5期30卷 802-812页

作者： Hongjian Lu Yiren Wang Deqing gan Jie wu Xiaojun wu School of Mining Engineering North China University of Science and TechnologyTangshan 063210China

To ensure safe and economical backfill mining,the mechanical response of the backfill–rock interaction system needs to be *** numerical investigation of the mechanical behavior of backfill–rock composite structure(BRCS)under triaxial compression,which includes deformation,failure patterns,strength characteristics,and acoustic emission(AE)evolution,was *** models used in the tests have one rough interface,two cement–iron tailings ratios(CTRs),four interface angles(IAs),and three confining pressures(CPs).Results showed that the deformation,strength characteristics,and failure patterns of BRCS under triaxial compression depend on IA,CP,and *** stress–strain curves of BRCS under triaxial compression could be divided into five stages,namely,compaction,elasticity,yield,strain softening,and residual *** relevant AE counts have corresponding relationships with different *** triaxial compressive strengths of composites increase linearly with the increase of the ***,the CP stress strengthening effect *** the IAs are45°and 60°,the failure areas of composites appear in the interface and *** the IAs are 75°and 90°,the failure areas of composites appear in the backfill,interface,and ***,the corresponding failure modes yield the combined shear *** research results provide the basis for further understanding of the stability of the BRCS.

关键词： backfill–rock composite structure triaxial compression mechanical behavior acoustic emission numerical simulation

An angular blinking jamming method based on electronically controlled corner reflectors

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Journal of Systems Engineering and Electronics 2024年第2期35卷 330-338页

作者： gan Lin wu Zehao WANG Xuesong LI Jianbing State Key Laboratory of Complex Electromagnetic Environmental Effects on Electronics and Information System National University of Defense TechnologyChangsha 410073China

Passive jamming is believed to have very good potential in countermeasure *** this paper,a passive angular blinking jamming method based on electronically controlled corner reflectors is *** amplitude of the incident wave can be modulated by switching the corner reflector between the penetration state and the reflection state,and the ensemble of multiple corner reflectors with towing rope can result in complex angle decoying *** of the decoying effect on corner reflectors’radar cross section and positions are analyzed and *** show that the angle measured by a monopulse radar can be significantly interfered by this method while the automatic tracking is employed.

关键词： monopulse radar angular blinking jamming corner reflector amplitude-comparison angle measurement metasurface

Preparation of Nanocrystalline Tin Dioxide Particles via the Acrylamide Polymerization Process

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稀有金属材料与工程 2006年第A3期35卷 581-582页

作者： Dongxiang Zhou huan Liu Shuping Gong Lihua huang Lu gan Department of Electronic Science ＆ Technology Huazhong University of Science ＆ Technology Wuhan 430074 China

We report simple acrylamide polymerization process to prepare nanocrystalline tin dioxide(SnO_2) particles.A small amount of the so-called premix solution(monofunctional acrylamide and difunctional N,N'-methylenebisacrylamide) was mixed with the aqueous solution of Sn^(4+) in certain proportion,and a few drops of ammonium persulfate solution were added as *** homogenized by magnetic stirring and heated to about 70℃,the mixed solution became a *** hydrous gel was directly decomposed by thermal treatment,resulting in obtaining rutile crystalline SnO_2 particles with a narrow size distribution typically in the range of 20 nm～40 nm.

关键词： SnO2 nanopowder acrylamide polyacrylamide gel

The Unsteady Fluctuating Pressure and Velocity in a Cross Flow Fan

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Journal of Thermal Science 2008年第4期17卷 349-355页

作者： Jiaye gan Fei Liu Min Liu Keqi wu State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 Chinaganjiaye0775 @ ***

This paper investigates the relations between the fluctuating pressure and velocity of the source by means of nu- merical method and sound pressure in the far field obtained with an noise experiment for a novel cross flow fan. The frequency characteristics of the fluctuating pressure and velocity in a cross flow fan are analyzed by means of spectral analysis and wavelet transform. The fluctuating pressures obtained by large eddy simulation on the casing wall are compared with that of experiments and show good agreement. From the spectral analysis of sound source, it is found that the pressure fluctuating peak is correspond with the sound pressure in the far field.

关键词： cross flow fan spectral analysis aerodynamic noise

Morphology control of magnetic properties in cobalt nanowires

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Rare Metals 2023年第6期42卷 1994-1999页

作者： huan-huan Xu Qiong wu Ming Yue Cheng-Lin Li Hong-Jian Li College of Materials Science and Engineering Beijing University of TechnologyBeijing100124China

Cobalt nanowires with different shapes and sizes were synthesized by reduction of carboxylate salts of Co^(Ⅱ) in 1,2-butanediol using a solvothermal chemical *** well-crystallized Co nanowires with hexagonal closepacked(hep) phase are observed and the(002) crystalline direction is along the long axis of nano *** morphology control is strongly dependent on the reaction *** varying the amount of capping agent in proper ranges,the effect of reaction parameters on controlling the size and shape of Co nanowires is *** the amount of capping agent increasing,the aspect ratio of Co nanowires increases ***,the magnetic measurement of cobalt nanowires shows that the coercivity of the Co nanocrystals does not increase with the increase in aspect ratio monotonously,which suggests that the tip shape and micros tructure also play an important role in the magnetization reversal process of the Co nanocrystals,and the aspect ratio plays a much less role as the ratio value exceeds *** further understand the effect of size on the magnetic properties in the Co nanowires,micromagnetic simulations were performed,which confirms that the magnetic properties are barely affected by the aspect ratio larger than *** highest coercivity of624 kA·m^(-1) is obtained for ellipsoid nano wires with a mean length of 200 nm,which also displays a strong magnetic *** a result,the highest energy product of the wires reaches 248 kJ·m^(-3).

关键词： Co nanowires Morphology control Tip shape High energy product

Bioabsorbable fabrication of molybdenum nitride/carbon nanocomposites for supercapacitors and metal ion batteries with robust stability

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Rare Metals 2023年第12期42卷 4212-4225页

作者： Qiang-Hong wu huan-Zhong Zeng You-Zhi wu Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals School of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730050China

Metal nitride is one of the best anode materials of the energy storage device;however,the low stability of the pure metal nitride limits its wide *** this work,a new method of bioabsorbable fabrication was developed for preparing molybdenum nitride that corporates into the porous carbon *** molybdenum ions in pollutions could be easily absorbed by Ligustrum quihoui,and the transportation,accumulation,and circulation of molybdenum ions in Ligustrum quihoui were *** obtained composite material of biochar and molybdenum nitride is employed as anode material of supercapacitors and batteries which exhibits good electrochemical performance,especially the rate and long lifespan ***,it is found that the specific capacity is344 F·g^(-1)at current density of 0.5 A·g^(-1)in 2 mol·L^(-1)KOH,and the capacitance retention and coulomb efficiency are above 90%after 10,000 *** should be noted that the novel approach combines fabricating anode materials with advanced nanostructure and suppressing the environmental problems with metal pollution at the same time.

关键词： Metal pollution Ligustrum quihoui Supercapacitors Metal ions batteries Anode materials

Possible Origins of the Western Pacific Warm Pool Decadal Variability

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Advances in Atmospheric Sciences 2012年第1期29卷 169-176页

作者： gan Bolan wu Lixin Physical Oceanography Laboratory Ocean University of China Qingdao 266100

In this study, the impacts of the Pacific Decadal Oscillation （PDO） and the Atlantic Multidecadal Oscillation （AMO） on the western Pacific warm pool （WPWP） were investigated. Our results show that the WPWP is linked with the PDO and the AMO at multiple time scales. On the seasonal time scales, the WPWP and the PDO/AMO reinforce each other, while at decadal time scales the forcing roles of the PDO and the AMO dominate. Notably, a positive PDO tends to enlarge the WPWP at both seasonal and decadal time scales, while a positive AMO tends to reduce the WPWP at decadal time scales. Furthermore, the decadal variability of the WPWP can be well predicted based on the PDO and AMO.

关键词： decadal variability western Pacific warm pool Pacific decadal oscillation Atlantic multi-decadal oscillation

A systematic review on the cost-effectiveness of the computer-assisted orthopedic system

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Health Care Science

Health Care Science 2022年第3期1卷 173-185页

作者： Hua Li Tengfeng Zhuang Wenrui wu Wenyi gan Chongjie wu Sijun Peng Songwei huan Ning Liu Department of Orthopaedics The First Affiliated Hospital of Jinan UniversityGuangzhouGuangdong ProvinceChina

Computer-assisted orthopedic system(CAOS)is rapidly gaining popularity in the field of precision ***,the cost-effectiveness of CAOS has not been well *** performed this review to summarize and assess the cost-effectiveness analyses(CEAs)with regard to *** on CEA in CAOS have been searched in PubMed and CEA Registry up to May 31,*** Quality of Health Economic Studies(QHES)instrument was used to estimate the quality of *** between qualities and potential factors were also *** were 15 eligible studies in the present *** studies evaluated CAOS joint arthroplasties and found that CAOS joint arthroplasties were cost-effective compared to manual *** studies focused on spinal surgery,two of which analyzed the costeffectiveness of CAOS for patients after spinal fusion,with conflicting *** study demonstrated that CAOS was cost-effective in spinal pedicle screw *** mean QHES score of CEAs included was *** potential factors had no significant relationship with the quality of *** on available studies,our review reflected that CAOS was cost-effective in the field of joint *** in spinal surgery,the answer was *** CEAs represent high qualities,and more CEAs are required in the different disciplines of orthopedics where CAOS is employed.

关键词： computer-assisted orthopedic system cost-effectiveness systematic review and meta-analysis