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足迹踏痕特征与步角相关关系研究 被引量:3
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作者 高毅 《中国人民公安大学学报(自然科学版)》 2014年第1期6-9,共4页
目的通过对大量足迹左右步角与踏痕的对比研究,建立踏痕特征与步角之间的相关性,为利用踏痕分析年龄提供更为准确的理论与实践依据。方法以足迹步法特征的理论与检验方法为基础,对案件高概率年龄段150人的步角与踏痕特征进行定量化研究... 目的通过对大量足迹左右步角与踏痕的对比研究,建立踏痕特征与步角之间的相关性,为利用踏痕分析年龄提供更为准确的理论与实践依据。方法以足迹步法特征的理论与检验方法为基础,对案件高概率年龄段150人的步角与踏痕特征进行定量化研究。结果踏痕的大小与范围随步角的变化而变化,通过统计得出对同一人,根据小步角所对应踏痕进行年龄分析更接近本人实际年龄。结论此方法在一定可靠的概率下可提高利用足迹踏痕分析年龄的准确度。 展开更多
关键词 步角 踏痕 步态特征 足迹分析
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现行步角测算中的误差分析及校正方法
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作者 郝延平 《江苏公安专科学校学报》 2000年第3期104-106,共3页
准确地测量出步角是确定步角特征的先决条件。步角通常小于30°,实践中常以57cm为半径测算步角,是因为当半径取57.296cm时其圆心角所对应的弧长(弦长)与步角的数值近似相等。步角测算误差随步角增大而增大,通过计算机数据分... 准确地测量出步角是确定步角特征的先决条件。步角通常小于30°,实践中常以57cm为半径测算步角,是因为当半径取57.296cm时其圆心角所对应的弧长(弦长)与步角的数值近似相等。步角测算误差随步角增大而增大,通过计算机数据分析,只要对弦长值进行适当修正,误差问题可以解决。 展开更多
关键词 刑事技术 足迹 步角 测算误差
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现行步角测算中的误差分析及校正方法
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作者 何粤华 殷亚军 杨修齐 《武警工程大学学报》 1995年第3期1-4,共4页
在刑事技术中,为了进行步幅分类,必先准确地测量出步角.现行步角测算的各种方法,或多或少地存在着误差.本文从理论上分析了误差形成的原因,通过对大量数据的计算机处理,得到了消除误差的校正值表,从而完善了步角测算方法,使其在使用过... 在刑事技术中,为了进行步幅分类,必先准确地测量出步角.现行步角测算的各种方法,或多或少地存在着误差.本文从理论上分析了误差形成的原因,通过对大量数据的计算机处理,得到了消除误差的校正值表,从而完善了步角测算方法,使其在使用过程中更加准确可靠. 展开更多
关键词 误差分析 步角 刑事技术 圆心角 实际应用 行步 角测 长值 中心线 四舍五入
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足迹步幅特征中有关概念的探讨 被引量:5
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作者 黄厚人 欧阳常青 《中国人民公安大学学报(自然科学版)》 2006年第2期17-20,共4页
我国公安高等院校的痕迹检验教材中,足迹步幅特征的某些概念不科学、不统一。足迹步幅特征中,步长、步宽、步角的6项指标,可以用来揭示人的行走运动规律,并可进行定量化检验,对现场足迹的分析与检验非常重要。而这6项指标都是以足迹步... 我国公安高等院校的痕迹检验教材中,足迹步幅特征的某些概念不科学、不统一。足迹步幅特征中,步长、步宽、步角的6项指标,可以用来揭示人的行走运动规律,并可进行定量化检验,对现场足迹的分析与检验非常重要。而这6项指标都是以足迹步行线为基准的。所以应在统一足迹步行线的定义的基础上,统一步长、步宽、步角的定义。 展开更多
关键词 足迹步行线 步长 步宽 步角
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基于二维主分量分析的成趟足迹特征提取方法 被引量:1
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作者 刘玉泽 方欣欣 暴田叶 《内蒙古工业大学学报(自然科学版)》 2009年第2期142-146,共5页
本文采用图象图形学的方法提取成趟足迹的特征值.首先,定义成趟足迹中左侧相邻单足足迹质心间的连线为左步行线,右侧相邻单足足迹质心间的连线为右步行线.第二,采用2D主分量分析(PCA)提取成趟足迹中每个单足足迹沿足长方向的特征向量.... 本文采用图象图形学的方法提取成趟足迹的特征值.首先,定义成趟足迹中左侧相邻单足足迹质心间的连线为左步行线,右侧相邻单足足迹质心间的连线为右步行线.第二,采用2D主分量分析(PCA)提取成趟足迹中每个单足足迹沿足长方向的特征向量.定义左步行线上足长特征向量与左步行线间在前进方向的夹角为左步角,右步行线上足长特征向量与右步行线间在前进方向的夹角为右步角.第三,设计了步行线,步长,步宽,步角的提取方法.对硬地地面成趟足迹样本所做的实验结果表明:对于经过同样预处理所得到的同一幅成趟足迹二值图象,提取的特征值是唯一的.本文提出的成趟足迹提取方法是可行的. 展开更多
关键词 成趟足迹 主分量分析(PCA) 步行线 步角 步长 步宽
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统计方法在足迹步幅特征检验技术中的应用 被引量:3
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作者 郑余梅 《北京警察学院学报》 1999年第2期30-33,共4页
统计方法是数学的一个分支,研究对象是带随机影响的数据。统计方法可以概括为两种,即描述统计和推断统计。描述统计侧重对统计资料的收集、整理、列表、图示。推断统计采用抽取部分样本对总体进行推理的方法,样本只是总体的一部分,包含... 统计方法是数学的一个分支,研究对象是带随机影响的数据。统计方法可以概括为两种,即描述统计和推断统计。描述统计侧重对统计资料的收集、整理、列表、图示。推断统计采用抽取部分样本对总体进行推理的方法,样本只是总体的一部分,包含的信息不完备。 展开更多
关键词 步幅 步长 特征量 检验法 上限值 样本容量 正态分布表 足迹 嫌疑对象 嫌疑人 正态总体 右步 左步 步角
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Descriptions of Three New Species of Orthogoniini (Coleoptera: Caraboidea) from Sumatra Island, Indonesia 被引量:1
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作者 田明义 Thierry DEUVE 《Entomotaxonomia》 CSCD 北大核心 2004年第1期23-28,共6页
In the present paper, two new species of Orthogonius Macleay and one new species of Hexachaetus Chaudoir (Coleoptera, Caraboidea, Orthogoniini) are described and illustrated from Sumatra Island, Indonesia.
关键词 COLEOPTERA Caraboidea Orthogoniini Orthogonius Hexachaetus new species SUMATRA
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Descriptions of Three New Species of Orthogonius Macleay (Coleoptera, Caraboidea, Orthogoniini) from Singapore and Southern Thailand 被引量:1
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作者 田明义 Thierry DEUVE 《Entomotaxonomia》 CSCD 北大核心 2003年第1期45-50,共6页
Three new species of Orthogonius Macleay (Coleoptera, Caraboidea) from Malaya Peninsula are described and illustrated in the present papr: O. solidicornis, sp. nov. (from Singapore), O. morvani, sp. nov. and O. thaicu... Three new species of Orthogonius Macleay (Coleoptera, Caraboidea) from Malaya Peninsula are described and illustrated in the present papr: O. solidicornis, sp. nov. (from Singapore), O. morvani, sp. nov. and O. thaicus, sp. nov. (from Thailand). 展开更多
关键词 COLEOPTERA Caraboidea Orthogoniini Orthogonius new species Thailand SINGAPORE
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A Provisional Species Checklist of the Oriental Orthogoninae (Coleoptera:Caraboidea)
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作者 田明义 THIERRY Deuve 《Entomotaxonomia》 CSCD 北大核心 2010年第B08期137-148,共12页
A provisional species checklist of the Oriental subfamily Orthogoninae is provided. Orthogonius dupuisi Tian et Deuve, 2006 (from Indonesia) is treated as a junior homonym of O. dupuisi Basilewsky, 1948 (from Rhode... A provisional species checklist of the Oriental subfamily Orthogoninae is provided. Orthogonius dupuisi Tian et Deuve, 2006 (from Indonesia) is treated as a junior homonym of O. dupuisi Basilewsky, 1948 (from Rhodesia), and therefore O. dupuisianus n. nom. is proposed. Actenocus punctatus Tian et Deuve, 2006 is confirmed as a good species, rather than a junior synonym of Orthogonius crassicrus Chaudoir, 1871 proposed by Kirschenhofer (2010). 展开更多
关键词 COLEOPTERA Caraboidea Orthogoninae CHECKLIST ORIENTAL HOMONYMY
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对足迹检验中级差检验法的案例应用
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作者 刘轶 张昆 《新疆警官高等专科学校学报》 2003年第1期33-35,共3页
在足迹鉴定中,对于一些因某种因素影响而形成的不正常的步幅特征的鉴定,除了运用一般的方法进行检验外,还应该运用一些定量检验的方法进行鉴定。通过对具体案例中级差检验法的实验,分析研究了由于心理因素和步行速度的影响使步幅特征中... 在足迹鉴定中,对于一些因某种因素影响而形成的不正常的步幅特征的鉴定,除了运用一般的方法进行检验外,还应该运用一些定量检验的方法进行鉴定。通过对具体案例中级差检验法的实验,分析研究了由于心理因素和步行速度的影响使步幅特征中各量值的变化情况,为此类案件提供了重要的检验依据。 展开更多
关键词 级差检验 步幅 步宽 步角 足迹鉴定
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Dynamic stability of quadruped robot walking on slope with trot gait 被引量:3
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作者 雷静桃 Ren Mingming 《High Technology Letters》 EI CAS 2016年第1期1-9,共9页
The dynamic stability of a quadruped robot trotting on slope was analyzed.Compared with crawl gait,trot gait can improve walking speed of quadruped robots.When a quadruped robot trots,each leg is in the alternate stat... The dynamic stability of a quadruped robot trotting on slope was analyzed.Compared with crawl gait,trot gait can improve walking speed of quadruped robots.When a quadruped robot trots,each leg is in the alternate state of swing phase or supporting phase,and two legs in the diagonal line are in the same phase.The feet in the supporting phase form a supporting region on the ground.When a quadruped robot walks on slope,the vertical distance from zero moment point(ZMP) to the supporting diagonal line is defined as ZMP offset distance.Whether this distance is less than the maximum offset distance or not,the stability of robot trotting on slope can be judged.The foot trajectory was planned with the sinusoidal function.Based on the kinematic analysis,the ZMP offset distance of quadruped robot under different slope angles,step length and step height was calculated,then the reasonable slope angle,step length and step height for quadruped robot trotting on slope to keep dynamic stability can be determined.On the other hand,the posture angle of quadruped robot should be controlled within the desired range.Computer simulations were executed to verify the theoretical analysis.The study will provide reference for determining reasonable step parameters of the quadruped robot. 展开更多
关键词 quadruped robot SLOPE trot gait STABILITY zero moment point (ZMP)
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Analysis of the Antenna's Setup Errors at the Global Navigation Satellite System Measurements
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作者 Evangelia Lambrou 《Journal of Civil Engineering and Architecture》 2013年第10期1279-1286,共8页
Today, the GNSS (global navigation satellite system) is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough a... Today, the GNSS (global navigation satellite system) is used for more complicate and accurate applications such as monitoring or stake out works. The truth lies in the fact that in the most of the times not enough attention is paid to the antenna's setup. Usually, gross errors are found in the antenna's centering, leveling and in the measurement of its height, which are significant. In this paper, a thoroughly analysis of the above mentioned errors is carried out. The influence of these errors in the calculation of the X, Y, Z Cartesian geocentric coordinates and the ~, 2, h ellipsoid geodetic coordinates of a point P on the earth's surface, is analyzed and is presented in several diagrams. Also a new convenient method for the accurate measurement of the antenna's height is presented and it is strongly proposed. The conclusions outline the magnitude of these errors and prove the significance of the antenna's proper setup at the accurate GNSS applications. 展开更多
关键词 GNSS antenna's height centering and leveling errors GNSS antenna's setup.
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A Note on Lattice Paths with Diagonal Steps in Three-Dimensional Space
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作者 卢青林 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2005年第3期447-450,共4页
Jr. Stocks[4] discussed lattice paths from (0, 0, 0) to (n, n, n) with diagonal steps under some restrictions. In this note, we give simpler formulas for the main results in [4], andextend them to a general case.
关键词 lattice path diagonal step Andre's reflection principle.
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On the non-synchronous rotation of binary systems
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作者 LI ZhiXiong HUANG RunQian WANG ShuMin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第6期1194-1200,共7页
During the evolution of the binary system, many physical processes occur, which can influence the orbital angular velocity and the spin angular velocities of the two components, and influence the non-synchronous or sy... During the evolution of the binary system, many physical processes occur, which can influence the orbital angular velocity and the spin angular velocities of the two components, and influence the non-synchronous or synchronous rotation of the system. These processes include the transfer of masses and angular momentums between the component stars, the loss of mass and angular momentum via stellar winds, and the deformation of the structure of component stars. A study of these processes indicates that they are closely related to the combined effects of tide and rotation. This means, to study the synchronous or non-synchronous rotation of binary systems, one has to consider the contributions of different physical processes simultaneously, instead of the tidal effect alone. A way to know whether the rotation of a binary system is synchronous or non-synchronous is to calculate the orbital angular velocity and the spin angular velocities of the component stars. If all of these angular velocities are equal, the rotation of the system is synchronous. If not, the rotation of the system is non-synchronous. For this aim, a series of equations are developed to calculate the orbital and spin angular velocities. The evolutionary calculation of a binary system with masses of 10M~ + 6Me shows that the transfer of masses and angular momentums between the two components, and the deformation of the components structure in the semidetached or in the contact phase can change the rotation of the system from synchronous into non-synchronous rotation. 展开更多
关键词 stars: rotation stars: evolution stars: binaries
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Time-stepping finite element analysis on the influence of skewed rotors and different skew angles on the losses of squirrel cage asynchronous motors 被引量:4
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作者 ZHAO HaiSen LIU XiaoFang +2 位作者 LUO YingLi CHEN WeiHua Peter BALDASSARI 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第9期2511-2519,共9页
To study the influence of skewed rotors and different skew angles on the losses of squirrel cage asynchronous motors,a 5.5-kW motor was taken as an example and the multi-sliced field-circuit coupled time stepping fini... To study the influence of skewed rotors and different skew angles on the losses of squirrel cage asynchronous motors,a 5.5-kW motor was taken as an example and the multi-sliced field-circuit coupled time stepping finite element method(T-S FEM)was used to analyze the axially non-uniform fundamental and harmonic field distribution characteristics at typical locations in the stator and rotor cores.The major conclusions are:firstly the skewed rotor exhibits a decrease in the harmonic copper losses caused by slot harmonic currents in the stator winding and rotor bars.Secondly,the skewed rotor shifts the non-uniform distribution of field in the axial direction,which leads to more severe saturation and an increase in iron losses.The heavier the load,the more pronounced the increase in iron losses.Furthermore,the influences of different skew angles on motor losses are studied systematically,with skew angles from 0.5 to 1.5 stator tooth pitch.It is found that the lowest total loss occurs at 0.8 stator tooth pitch,and the slot harmonics can be decreased effectively. 展开更多
关键词 squirrel cage asynchronous motors skewed rotors LOSSES time-stepping finite element method (T-S FEM)
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A dynamic phasor estimation algorithm based on angle-shifted energy operator 被引量:1
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作者 JIN XiaNing WANG FuPing WANG ZanJi 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第6期1322-1329,共8页
Under dynamic conditions, the signals of power system have time-varying magnitude and frequency, which might lead to considerable errors for synchrophasor measurement. The traditional discrete Fourier transform (DFT) ... Under dynamic conditions, the signals of power system have time-varying magnitude and frequency, which might lead to considerable errors for synchrophasor measurement. The traditional discrete Fourier transform (DFT) based algorithms used in Phasor Measurement Unit (PMU) are hard to meet the requirements of measurement accuracy because of the existence of spectral leakage. A dynamic phasor measurement algorithm is proposed in this paper in which the input sampled data are considered as non-stationary signals with amplitude modulation-frequency modulation (AM-FM) form, and the measurement is achieved by AM-FM demodulation. An angle-shifted energy operator (ASEO) is used to extract the instantaneous amplitude and low pass differential filter is introduced for frequency estimation. Simulation results indicate that the proposed algorithm can effectively improve the phasor measurement accuracy and has very short response time for PMU under dynamic conditions. 展开更多
关键词 synchronous phasor measurement discrete Fourier transform (DFT) dynamic conditions energy operator
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Fabrication of triangular fiber Bragg grating based on the one-step method
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作者 周倩 宁提纲 +4 位作者 李晶 胡旭东 裴丽 祈春慧 郑晶 《Optoelectronics Letters》 EI 2011年第1期15-18,共4页
A new method is presented to fabricate the triangular fiber Bragg grating(TFBG).The fabrication device is simple,only requires a single exposure and does not need to write complicated program.The transfer matrix metho... A new method is presented to fabricate the triangular fiber Bragg grating(TFBG).The fabrication device is simple,only requires a single exposure and does not need to write complicated program.The transfer matrix method is used to design the fiber Bragg grating,and the grating resonant wavelength and the grating reflectivity can be controlled in order to achieve the triangular spectrum.With different fiber tilt angles,the available bandwidth of TFBG,the linearity and the oblique gradient are also different.In the experiment,the angles 1°,1.5° and 2° are chosen.The results show that the best angle value is 1.5°,and the TFBG has a good linearity,greater gradient and wider available bandwidth. 展开更多
关键词 BANDWIDTH Fiber Bragg gratings Fiber optic components Fiber optic sensors Fibers
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