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Advances in measurement of knee kinematics during gait:application of a new imaging technique
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作者 Guoan Li(Bioengineering Lab,Department of Orthopaedic Surgery Massachusetts General Hospital and Harvard Medical School,Boston,MA 02114,USA) 《医用生物力学》 EI CAS CSCD 2010年第S1期58-59,共2页
Introduction Most of our knowledge of knee kinematics during gait is based on studies measuring knee motion using external skin markers. While these studies have dramatically improved our knowledge of human gait it re... Introduction Most of our knowledge of knee kinematics during gait is based on studies measuring knee motion using external skin markers. While these studies have dramatically improved our knowledge of human gait it remains a challenge to 展开更多
关键词 Advances in measurement of knee kinematics during gait
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Measuring the kinematics of a free-flying hawk-moth(Macroglossum stellatarum)by a comb-fringe projection method 被引量:1
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作者 Guanhao Wu Li jiang Zeng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2010年第1期67-71,共5页
We describe a 2D fringe projection method that involves projecting two groups of sharp comb fringes onto a free-flying hawk-moth from different directions and recording the images of distorted fringes by two high spee... We describe a 2D fringe projection method that involves projecting two groups of sharp comb fringes onto a free-flying hawk-moth from different directions and recording the images of distorted fringes by two high speed cameras from two orthogonal views. By calculating the 3D coordinates of the points on the hawk-moth and three-dimensional reconstruction of the wing, the flight trajectory, body attitude and wing kinematics including flapping angle, elevation angle, torsion angle, and camber deformation are obtained. 展开更多
关键词 Fringe projection kinematics measurement Hawk-moth
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Automated Kinematics Measurement and Aerodynamics of a Bioinspired Flapping Rotary Wing 被引量:6
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作者 Jianghao Wu Jian Qiu Yanlai Zhang 《Journal of Bionic Engineering》 SCIE EI CSCD 2017年第4期726-737,共12页
A physical model for a micro air vehicle with Flapping Rotary Wings (FRW) is investigated by measuring the wing kine- matics in trim conditions and computing the corresponding aerodynamic force using computational f... A physical model for a micro air vehicle with Flapping Rotary Wings (FRW) is investigated by measuring the wing kine- matics in trim conditions and computing the corresponding aerodynamic force using computational fluid dynamics. In order to capture the motion image and reconstruct the positions and orientations of the wing, the photogrammetric method is adopted and a method for automated recognition of the marked points is developed. The characteristics of the realistic wing kinematics are presented. The results show that the non-dimensional rotating speed is a linear function of non-dimensional flapping frequency regardless of the initial angles of attack. Moreover, the effects of wing kinematics on aerodynamic force production and the underlying mechanism are analyzed. The results show that the wing passive pitching caused by elastic deformation can sig- nificantly enhance lift production. The Strouhal number of the FRW is much higher than that of general flapping wings, indi- cating the stronger unsteadiness of flows in FRW. 展开更多
关键词 bioinspired flapping rotary wing AERODYNAMICS wing kinematics measurement computational fluid dynamics micro air vehicle
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ON GENERALIZED BUFFON NEEDLE PROBLEM FOR LATTICES 被引量:3
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作者 谢凤繁 李德宜 《Acta Mathematica Scientia》 SCIE CSCD 2011年第1期303-308,共6页
Two new concepts, the generalized support function and restricted chord function, both referring to a convex set, were introduced in [1]. General formulae to yield the kinematic measure of a segment of fixed length in... Two new concepts, the generalized support function and restricted chord function, both referring to a convex set, were introduced in [1]. General formulae to yield the kinematic measure of a segment of fixed length in a convex set were established based on these concepts. In this article , using the partial intersection method, we consider the generalized Buffon problem for three kinds of lattices. We determine the probability of intersection of a body test needle of length l, l a. 展开更多
关键词 Geometric probability integral geometry Buffon problem lattice of regions kinematic measure
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Experimental Study of Two-Alpha Emission from High-Lying Excited States of ^(17,18)Ne 被引量:1
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作者 徐新星 林承键 +17 位作者 贾会明 杨峰 贾飞 吴振东 张世涛 刘祖华 张焕乔 徐瑚珊 孙志宇 王建松 胡正国 王猛 陈若富 张雪荧 李琛 雷祥国 徐治国 肖国青 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第5期371-374,共4页
The experiments of two-alpha emission from 17,18^Ne excited levels were performed at the HIRFL-RIBLL facility of the Institute of Modern Physics, Lanzhou. The beams of 17^Ne at the energy of 49.9 MeV/u and lSNe at 51.... The experiments of two-alpha emission from 17,18^Ne excited levels were performed at the HIRFL-RIBLL facility of the Institute of Modern Physics, Lanzhou. The beams of 17^Ne at the energy of 49.9 MeV/u and lSNe at 51.8 MeV/u bombarded a 197Au target to populate excited states of 17,18^Ne via Coulomb excitation. Complete kinematics measurements were achieved by the detectors of a silicon strip and CsI+PIN array. The experimental results combined with simple MC simulations show the characteristic of sequential two-alpha emission via 140 excited states for lSNe. The results of two-alpha emission from 17^Ne are preliminary and need further analyses. 展开更多
关键词 two-alpha emission Coulomb excitation complete kinematics measurements sequential emission
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THE CONFIDENCE EVALUATION FOR AIRBORNE GPS DATA 被引量:1
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作者 LIU Jiyu CHEN Xiaoming 《Geo-Spatial Information Science》 2000年第1期50-56,共7页
GPS kinematic carrier phase measurements can be used to determine seven di- mension state and three attitude parameters of a motional carrier,such as an aircraft or a low- earth-orbit spacecraft,on which an antenna is... GPS kinematic carrier phase measurements can be used to determine seven di- mension state and three attitude parameters of a motional carrier,such as an aircraft or a low- earth-orbit spacecraft,on which an antenna is installed to receive GPS signals. It is known from airborne GPS test results for photogrammetry in China since 1994 that GPS carrier phase measurements in a motional environment have acquired external accuracies of ± 7. 9cm for two dimensional positions and ± 18. 1cm for point heights. This paper describes airborne GPS carrier phase -measurements with multireference stations and discusses how to evaluate the confidence of GPS kinematic data. 展开更多
关键词 airborne GPS receiver GPS kinematic carrier phase measurement multireferene ground station
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Automated pavement horizontal curve measurement methods based on inertial measurement unit and 3D profiling data 被引量:8
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作者 Wenting Luo Lin Li Kelvin C.P.Wang 《Journal of Traffic and Transportation Engineering(English Edition)》 2016年第2期137-145,共9页
Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditiona... Pavement horizontal curve is designed to serve as a transition between straight segments, and its presence may cause a series of driving-related safety issues to motorists and drivers. As is recognized that traditional methods for curve geometry investigation are time consuming, labor intensive, and inaccurate, this study attempts to develop a method that can automatically conduct horizontal curve identification and measurement at network level. The digital highway data vehicle (DHDV) was utilized for data collection, in which three Euler angles, driving speed, and acceleration of survey vehicle were measured with an inertial measurement unit (IMU). The 3D profiling data used for cross slope calibration was obtained with PaveVision3D Ultra technology at 1 mm resolution. In this study, the curve identification was based on the variation of heading angle, and the curve radius was calculated with ki- nematic method, geometry method, and lateral acceleration method. In order to verify the accuracy of the three methods, the analysis of variance (ANOVA) test was applied by using the control variable of curve radius measured by field test. Based on the measured curve radius, a curve safety analysis model was used to predict the crash rates and safe driving speeds at horizontal curves. Finally, a case study on 4.35 km road segment demonstrated that the proposed method could efficiently conduct network level analysis. 展开更多
关键词 Horizontal curve Inertial measurement unit (IMU) Curve radius kinematic method Geometry method Lateral acceleration method ANOVA test Curve safety analysis
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