追踪

The result from the three simulation model continues that two step synthesis method is one effective ray tracing method.Because it can accurately persue the least travel time of ray fast and have very strong antinoise nature, so it can be used to the complex medium tomography analysis.

通过构造的数值模型验证了改进算法，表明该算法是一种有效的射线追踪方法，能快速准确的追踪射线的最小走时数据并且具有很强的抗噪性，可以应用到复杂介质的层析成像中。

The interactive bibliotherapy group had significant follow-up effect on subjects' socially withdrawn behavior and social skill, but not on self-concept and social anxiety.

读书治疗互动组对社会畏缩行为、社会技巧具有追踪辅导效果，对自我概念、社会焦虑的追踪辅导效果未达显著。

This paper introduces different signal block modes and the method which was used to calculate tracking intervals between trains, and establishes simulation system for multi-train tracking. A case was designed for analysis.

介绍了城市轨道交通不同信号闭塞方式及其追踪列车间隔时间的计算方法，建立了多列车追踪运行的仿真系统，并进行了算例的设计。

C. Complete BPI projects and apply BPI Project Tracking Web tool to track JQE BPI status.

在BPI计划追踪的网页上传和追踪BPI计划状况

With the object correspondence, the occlusion problem can be solved easily and the 3-D probability distribution of moving objects can also be estimated more precisely. These advantages make the results of objects tracking and correspondence more robust and reliable.

有了物体的对应关系，就可以解决物体交错所造成的追踪错误，并且能够更加正确的估测三维物体的机率分布，使多物体的追踪和对应更加准确而可靠。

After the human is detected and extracted, we then track body parts of the human by using appearances of these parts as the features and using particle filters as the tracking kernel. In the particle filter, we adopt color histograms as the appearance features and use a specific histogram mapping to enhance the discriminability between different objects. To form a robust tracker that can distinguish target objects from background objects that have color distribution similar to those of target objects, we calculate the target similarity from both the target object model and the background model.

当人体被侦测及切割出来后，接著我们使用人体部位外观当作特徵并且使用粒子滤波器作为核心来追踪此人体，我们采等化之颜色统计表当作粒子滤波器中使用的外观特徵以强化不同物体的鉴别率，为了建立可稳健区别目标物及背景物体的追踪器，我们同时使用目标的模型和背景模型来计算目标物的相似度，为了对抗背景及目标物的外观变化，背景模型及目标物模型都是可适应变化的。

According to the information of mobile sensor nodes and the range data by apperceiving the target,in the method,the position of the target can be calculated.Then the tracked orientation of every source node can be located according to the position of source nodes and target nodes,so the target can be tracked by source nodes based on these orientation.

利用测距定位的移动追踪方法，根据移动传感器信源节点的信息及感知目标所得的测距数据，推算出目标的位置，由信源节点与目标节点的位置分别确定各个信源节点的追踪方向，使移动传感器信源节点沿该方向追踪目标。

Moderate noise (75、85dBA), didn't has significant effect on simple control and reaction task such as two-hand coordinate tracking, complex reaction time and persuit aiming. After sustained exposure of 1. 5h to noise with intensity of 85、95 dB , there was a tendency to decrease in light tracking performance of dual task (light tracking and oddball vedio-moter reaction) with a very large difference among subjects. The attention distribution between main task and second task changed.

中等强度的噪声（75、85dBA），对于双手协调光标追踪、复杂反应时及目标跟踪等较为简单的操纵和反应并无显著影响；85、95dB强度的噪声持续暴露1.5h，可使双重任务（光标追踪和oddball视觉-运动反应）的光标追踪绩效有降低的趋势，并有很大的个体差异，主、次任务之间的注意分配发生了改变。

The article presents the developing condition of PWM and SVPWM first.Then the theory of SVPWM is discussed in detail.The SVPWM is based on the thought of magnetic chain tracking.It makes the ideal magnetic chain circle of three-phased sysmmetry electric motor supplied by three-phased sysmmetry sine wave voltage for basis,uses the practical magnetic chain vector formed by the different switch modes of three-phased inverter to track the basic magnetic chain circle.During the course of tracking,the inverter changes the switch modes properly to form the PWM waves.Then the modulation wave of SVPWM is analyzed in detail.The modulation wave of SVPWM is implicit,but the analogous modulation wave in A-B-C axis needs to be calculated in order to expose the internal relation of SVPWM and SPWM.That is to show the implicit modulation wave of SVPWM. SVPWM actually is a transformed SPWM ruly sampled by the modulation wave which is injected by the zero prefaces based on space vectors.

本文首先对脉宽调制技术的发展现状进行了综述，在此基础上分析了电压空间矢量脉宽调制技术的发展现状；接着对空间电压矢量脉宽调制技术的基本原理进行了详细的分析和推导，SVPWM是基于磁链追踪的思想，它以三相对称正弦波电压供电下三相对称电动机定子理想磁链圆为基准，由三相逆变器不同开关模式下所形成的实际磁链矢量来追踪基准磁链圆的，在追踪的过程中，逆变器的开关模式作适当的切换，从而形成PWM波；然后详细分析了电压空间矢量脉宽调制技术的调制波，虽然SVPWM法的调制波是隐含的，但是为了揭示SVPWM法与SPWM法的内在联系，需要求出SVPWM在A-B-C坐标系上的等效调制波，也就是将SVPWM的隐含调制波显化；SVPWM实质是一种基于空间矢量在三相正弦波中注入了零序分量的调制波进行规则采样的一种变形SPWM。

Lastly, a new target-tracking algorithm based on dynamic cluster is proposed. It improves the disadvantages of localization and tracking in DPT.

最后，针对动态的预测追踪算法目标定位不准确、无法追踪速度大的目标等缺点提出了一种基于动态簇的无线传感器网络目标追踪算法。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。