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基于高斯过程的表情动作单元跟踪技术 被引量:5
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作者 王磊 邹北骥 +1 位作者 彭小宁 潘丽丽 《电子学报》 EI CAS CSCD 北大核心 2007年第11期2087-2091,共5页
在表情动作单元的跟踪中有两个常见问题:一是跟踪结果有小幅而频繁的抖动;二是跟踪过程会产生难以检测的误差.针对这两个问题,本文提出了一种基于高斯过程和粒子滤波的表情动作单元跟踪技术.实验结果表明本文算法比传统的梯度优化和粒... 在表情动作单元的跟踪中有两个常见问题:一是跟踪结果有小幅而频繁的抖动;二是跟踪过程会产生难以检测的误差.针对这两个问题,本文提出了一种基于高斯过程和粒子滤波的表情动作单元跟踪技术.实验结果表明本文算法比传统的梯度优化和粒子滤波法具有更好的平滑性和跟踪精度,而精度的优势在头部有偏转的情况下尤为突出. 展开更多
关键词 表情动作单元跟踪 梯度优化 粒子滤波 高斯过程
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星间激光通信中四象限探测器的定位精度研究 被引量:2
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作者 李树德 刘彩霞 +2 位作者 徐林 安建欣 刘政 《光通信研究》 2021年第4期61-65,共5页
在星间激光通信中,精跟踪单元常采用四象限探测器用于光斑位置定位,定位误差的大小直接影响精跟踪单元的测角精度。为实现微弧度量级的测角精度,文章研究了影响探测器定位误差的各个噪声因素,并根据星间光通信的实际情况进行了简化分析... 在星间激光通信中,精跟踪单元常采用四象限探测器用于光斑位置定位,定位误差的大小直接影响精跟踪单元的测角精度。为实现微弧度量级的测角精度,文章研究了影响探测器定位误差的各个噪声因素,并根据星间光通信的实际情况进行了简化分析,提出了定位误差的具体计算方法,最后通过具体算例评估了各噪声因素的影响程度。研究结果表明,提高发射功率可以在一定范围内提高接收端信号的信噪比,减小定位误差,进而减小测角误差,提高测角精度。但定位误差并非随发射功率的增大而线性减小,当发射功率增大到一定程度之后,定位误差的减小有限,这时再单纯通过增大发射功率来提高测角精度代价将非常大。 展开更多
关键词 四象限光电探测器 定位误差 噪声因素 跟踪单元
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倾翻式托盘分拣机在机场行李处理系统中的应用 被引量:1
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作者 陶希 《科技创新与生产力》 2014年第10期62-63,67,共3页
通过化整为零的方法,依次介绍了分拣系统机械部分的若干重要部分、自控部分的控制原理及完成精密控制所需要的若干电气单元。论证了此系统如何完成高竞速的整理行李分拣流程,同时结合笔者多年维护工作经验,总结得出了此系统的集中常见... 通过化整为零的方法,依次介绍了分拣系统机械部分的若干重要部分、自控部分的控制原理及完成精密控制所需要的若干电气单元。论证了此系统如何完成高竞速的整理行李分拣流程,同时结合笔者多年维护工作经验,总结得出了此系统的集中常见故障机应对措施。 展开更多
关键词 倾翻箱 环箍 跟踪单元 计数单元 直线电机
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基于ARM的非开挖钻进轨迹控制系统设计 被引量:2
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作者 王福忠 高彩霞 余淋 《河南理工大学学报(自然科学版)》 CAS 2010年第1期75-79,共5页
在分析非开挖钻机钻进轨迹控制系统设计原则的基础上,讨论非开挖钻机导向系统的探头单元、跟踪器单元和同步器单元的硬件组成及设计方法,以及各部分的接口电路及元件参数;设计基于ARM的非开挖钻机的钻进轨迹控制系统,为非开挖钻进铺管... 在分析非开挖钻机钻进轨迹控制系统设计原则的基础上,讨论非开挖钻机导向系统的探头单元、跟踪器单元和同步器单元的硬件组成及设计方法,以及各部分的接口电路及元件参数;设计基于ARM的非开挖钻机的钻进轨迹控制系统,为非开挖钻进铺管技术的推广应用和提高非开挖钻机的自动化水平提供了技术支持. 展开更多
关键词 非开挖钻机 钻进轨迹 探头单元 跟踪单元 同步器单元
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Particle filter based on iterated importance density function and parallel resampling 被引量:1
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作者 武勇 王俊 曹运合 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3427-3439,共13页
The design, analysis and parallel implementation of particle filter(PF) were investigated. Firstly, to tackle the particle degeneracy problem in the PF, an iterated importance density function(IIDF) was proposed, wher... The design, analysis and parallel implementation of particle filter(PF) were investigated. Firstly, to tackle the particle degeneracy problem in the PF, an iterated importance density function(IIDF) was proposed, where a new term associating with the current measurement information(CMI) was introduced into the expression of the sampled particles. Through the repeated use of the least squares estimate, the CMI can be integrated into the sampling stage in an iterative manner, conducing to the greatly improved sampling quality. By running the IIDF, an iterated PF(IPF) can be obtained. Subsequently, a parallel resampling(PR) was proposed for the purpose of parallel implementation of IPF, whose main idea was the same as systematic resampling(SR) but performed differently. The PR directly used the integral part of the product of the particle weight and particle number as the number of times that a particle was replicated, and it simultaneously eliminated the particles with the smallest weights, which are the two key differences from the SR. The detailed implementation procedures on the graphics processing unit of IPF based on the PR were presented at last. The performance of the IPF, PR and their parallel implementations are illustrated via one-dimensional numerical simulation and practical application of passive radar target tracking. 展开更多
关键词 particle filter iterated importance density function least squares estimate parallel resampling graphics processing unit
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XM推出实时气象资料服务
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《中国交通信息产业》 2003年第5期30-30,共1页
关键词 XM卫星通信公司 单元识别和跟踪 NEXRAD雷达系统 “Weather Works”公司 实时气象资料 工作原理
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Application of ICP-MS trace element analysis in study of ancient Chinese ceramics
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作者 LIBaoping ZHAOJianxin KennethD.Collerson AlanGreig 《Chinese Science Bulletin》 SCIE CAS 2003年第2期1219-1224,共6页
Thirty-nine trace elements of the Song-Yuan period (960-1368 AD) porcelain bodies from Cizhou, Jizhou and Longquanwu kilns were analyzed with ICP-MS, a technique rarely used in Chinese archaeometry, to investigate its... Thirty-nine trace elements of the Song-Yuan period (960-1368 AD) porcelain bodies from Cizhou, Jizhou and Longquanwu kilns were analyzed with ICP-MS, a technique rarely used in Chinese archaeometry, to investigate its potential application in such studies. Trace element compositions clearly reflect the distinctive raw materials and their mineralogy at the three kilns and allow their products to be distinguished. Significant chemical variations are also observed between Yuan and Song-Jing dynasties samples from Cizhou as well as fine and coarse porcelain bodies from Longquanwu. In Cizhou, porcelains of better quality which imitate the famous Ding kiln have trace element features distinctive from ordinary Cizhou products, that indicates geochemically distinctive raw materials were used and which possibly also underwent extra refining prior to use. The distinct trace element features of different kilns and the various types of porcelains from an individual kiln can be interpreted from a geochemical perspective. ICP-MS can provide a large amount of valuable information about ancient Chinese ceramics as it is capable of analyzing >40 elements with a typical of precision < 2%. 展开更多
关键词 中国 古代制瓷业 ICP-MS跟踪单元 宋朝 元朝 化学分析 窑炉 考古定年学
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