改进Haar-like特征联合CamShift算法用于车辆跟踪

提出一种改进的Haar特征获取方法,并结合CamShift算法提取车辆检测信号实现特定车辆实时跟踪。首先利用倾斜45°特征与像素和的商计算信号的Haar特征值;其次利用AdaBoost算法训练样本得到特征信号分类器,构建特征信号样本级联分类器,利用获得的级联分类器对视频信号进行检测;最后将检测结果中的特定车辆外切矩形作为CamShift算法的初始窗口,并对CamShift算法后续跟踪窗口进行检测,以提高检测效率和跟踪实时性。实验表明,该方法对车辆图像信号具有较好的检测效果,对特定车辆跟踪具有较高的实时性。     

考虑遮挡的视频车辆跟踪

为了对遮挡情况下的运动车辆进行跟踪,提出一种基于分块的车辆跟踪算法。该算法将目标车辆以可重叠的方式划分为若干大小一致的子块。在分块的基础上估计所有子块的运动矢量,检测噪声运动矢量并进行调整,以减少运动矢量估计的误差,然后对子块进行移位以实现车辆跟踪。为了处理车辆间的遮挡现象建立了马尔可夫随机场描述子块之间的关系,利用欧氏距离定义块的邻域,并基于块的直方图构建能量函数,最后利用模拟退火法对能量函数进行优化,以对遮挡区域进行分割。实验结果表明,该算法能够对遮挡车辆进行准确跟踪。     

基于计算机视觉的运动目标跟踪算法研究

随着计算机技术的飞速发展,视频图像处理技术得到了显著的提高.本文提出了一种基于计算机视觉的运动目标跟踪方法.在Marr的计算理论框架下,我们引入通过自下而上的视觉跟踪处理方法来进行运动目标跟踪,本文以车辆视频为例,选用Robert算子对车辆进行边缘检测,针对车辆在运动过程中大小和姿态变化的情况,提出了基于多关联模板匹配方法进行跟踪.实验表明本文的算法分离的精度增强,跟踪效果好,并且能很好地满足实时性.     

基于分层光流场的运动车辆检测与跟踪

针对LK(Lucas Kanade)算法不能稳定跟踪快速移动目标的局限性,采用一种图像分层光流的跟踪方法,能获得针对目标的大尺度运动的较好预测结果.为了减少计算量,提出一种基于特征角点的光流跟踪技术,首先提取运动车辆的特征角点,计算其光流场,对角点实施跟踪极大地减少了光流计算量,可以满足目标检测实时性的要求.实验表明,当运动车辆转弯和移动时,角点始终稳定可靠,并且跟踪算法能够快速、准确地匹配特征焦点,实现了复杂交通场景下对运动车辆的实时稳定跟踪.     

基于树形尺度估计的车辆跟踪

为解决智能视频监控系统车辆跟踪过程中尺度伸缩变化造成的跟踪器模型漂移的问题,在SiamFC(基于全连接层的孪生网络目标跟踪算法)的基础上,提出一种基于树形尺度池的车辆跟踪算法.通过判断当前图片与模板图片中目标的大小,为其分配尺度因子,再通过尺度因子之间的响应大小确定当前目标的最佳尺度.此外,为保证模板图片能够适应车辆外...     

基于视频的道路车辆测速系统设计与实现

为了对道路上行驶的车辆速度进行有效估计,提出了一种基于Harris Stephen角点检测算法和归一化互相关（Normalized Cross Correlation method,NCC）匹配算法的视频车辆检测系统。该系统对车辆进行跟踪,并测算车辆在干道和高速公路上的速度。通过使用Harris Stephen角点检测兴趣点,利用归一化互相关算法匹配对应角点,利用点对应关系确定车辆行驶的像素位移。根据车辆在连续视频帧中所有角点的总位移计算车辆的平均位移,结合帧率估计车速。实验结果表明,系统测速精度高,能实时估计出车辆行进的速度。     

智能车辆轨迹跟踪控制器设计

智能车辆在弯道下轨迹跟踪精确性与稳定性较差,尤其是在低附着路面上容易发生失稳及侧滑。建立车辆三由度动力学模型和准线性轮胎模型,通过模型预测控制算法得出理想的转向角作为车辆输入,通过道路曲率及道路附着系数获取期望车速,并使用PID算法跟踪车辆速度。最后利用MATLAB/Simulink与CarSim进行联合仿真验证。仿真结果表明,该控制器可在低附路面、变车速的工况下跟踪期望路径,且稳定性较好。     

基于传感器融合的一种多目标车辆识别跟踪方法

为使无人驾驶汽车在公路环境中有效实现安全避障和行驶,提出一种基于雷达和视觉传感器融合的多目标车辆识别跟踪的方法.在无人驾驶汽车上部署6个高分辨率雷达传感器和2个视觉传感器,利用联合概率数据关联算法,将目标与雷达回波点迹进行关联,利用YOLOV2深度神经网络对视频序列中的图像进行对象识别和定位,并综合2种传感器,在时间和空间上进行标定,从而识别车道上的汽车,然后利用扩展卡尔曼滤波算法,跟踪被识别的车辆,最后应用MATLAB软件建模仿真.仿真结果验证:该方法能使无人驾驶汽车有效识别和跟踪公路上静止和移动的汽车目标,为无人驾驶汽车后继的决策规划控制提供了感知层信号.     

基于增量学习的稀疏表示仿射目标跟踪算法研究

针对传统目标跟踪算法在背景复杂.目标形态和光照条件剧烈变化情况下跟踪效果不佳的问题,提出了一种新的目标跟踪算法.该算法在粒子滤波框架下用仿射变换和Gabor特征表示图像,用模板字典稀疏表示候选目标,并用增量学习算法对模板字典进行更新.试验部分将该算法与其他跟踪算法在Matlab平台上进行比较,试验结果表明该算法具有鲁棒性强、跟踪效果好的优点.     

一种针对人体运动目标的Mean-Shift跟踪算法

针对传统的Mean-Shift目标跟踪算法在跟踪人体运动目标时的不足,提出了一种基于Mean-Shift目标跟踪算法的人体目标跟踪方法。该方法首先利用人眼视觉阈值效应和区域生长法检测目标,再用Mean-Shift跟踪算法对目标进行跟踪。实验表明该方法大幅提高了人体运动目标的跟踪精度。     

基于卡尔曼滤波的运动车辆序列图像参数估计

运动目标的参数估计是近代计算机视觉领域重要的研究课题．以运动车辆的序列图像为例来分析．考虑到跟踪运动车辆对实时性要求较高的特性,没有采用经典的最小二乘滤波和维纳滤波等,而采用了卡尔曼滤波方法,由于卡尔曼滤波在时域内进行,因此不需要保存更多的数据,使得跟踪结果实时输出。     

基于RFID技术的电动车防盗监控平台设计

为了更好地满足电动车防盗需求,提高被盗电动车辆追踪效率、节约时间并降低人力成本,基于RFID技术设计了电动车防盗监控平台。平台由Web服务器集群、Nginx负载均衡器与数据库组成,阐述了平台各部分设计并进行性能测试。测试结果表明,该电动车防盗平台运行稳定、易于操作,能够在车辆被盗时及时帮助失主找回车辆,可基本满足电动车防盗的业务需求,并且能够较好地应对高并发访问。     

Automatic target tracking on multi-resolution terrain

INTRODUCTION In this paper, we propose an automatic target tracking method in our real-time simulation and animation system of large-scale terrain field. Our system supplies autonomous guidance, navigation and control of moving objects, in order to efficiently perform related challenging missions in manufacture, entertainment, and other real-world applications. Our goal is to deploy a large number of moving vehicles upon a large-scale virtual terrain (essentially a 2D curved terrain surfa…     

Eye tracking as a tool to study and enhance multimedia learning

This special issue comprises a set of six papers, in which studies are presented that use eye tracking to analyse multimedia learning processes in detail. Most of the papers focus on the effects on visual attention of animations with different design features such as spoken vs. written text, different kinds of cues, or different presentation speeds. Two contributions concern effects of learner characteristics (prior knowledge) on visual attention when learning with video and complex graphics. In addition, in some papers eye tracking is not only used as a process measure in itself, but also as input for verbal reports (i.e., cued retrospective reporting). In the two commentaries, the contributions are discussed from a multimedia learning perspective and an eye tracking perspective, by prominent researchers in those fields. Together, the contributions to this issue give an overview of the various possibilities eye tracking opens up for research on multimedia learning and instruction.     

Segregated Classrooms,Integrated Intent: How One School Responded to the Challenge of Developing Positive Interethnic Relations

Children who feel unsafe in school because of threats of violence or verbal abuse based on race, ethnicity, or language cannot focus on the learning and achievement goals that the U.S. educational system has placed before us in the form of national standards. A primary need for some schools is to create a safe and secure environment and to ensure that children and adults of different backgrounds feel respected. Yet this raises an interesting question: Can schools be vehicles for improving race relations? In this article, I draw on a case study of 1 elementary school, Cornell,1 to examine this question in depth. Many would answer that, given historical inequities such as segregation and tracking, schools are unlikely places for improvements in race or ethnic relations to take place. On the other hand, schools do create cultures and norms of their own that may deviate in some ways from the national culture, and in this sense they represent a potential site for change in race relations, at least locally.     

Exploring students’ engineering designs through open-ended assignments

ABSTRACT

This paper aims at presenting the experience of the Power Conversion project in teaching students to design a proof-of-principle contactless energy transfer system for the charging of electrical vehicles. The Power Conversion is a second-year electrical engineering (EE) project in which students are to gather and apply EE knowledge to design and test a system. This system is to work with power level and operates independent from an electricity grid. The instructional method used in this project is design-based learning (DBL). As an educational approach, DBL is to support students to gather and apply knowledge in open-ended assignments. The set-up of the project has gone through different modifications and iterations in three consecutive years regarding the organisation and supervision of the students. We have analysed the students’ design products in the past three academic years in order to evaluate whether the project set-up and supervision have influenced students’ designs. Results indicate that the open-ended character of the project has a positive influence on the designs especially regarding the criteria on efficiency, Maximum Power Point Tracking algorithm and power tracking.     

Eye tracking methodology for studying teacher learning: a review of the research

ABSTRACT

Eye tracking methodology offers insights into human attention, decision-making processes, and user behaviours. In the context of teacher learning, data generated from eye-tracking technology has the potential to provide important information about teachers’ behavioural patterns and cognitive processes that may or may not be occurring during learning experiences. This review analyses existing studies that use eye tracking methodology for studying teacher learning. The authors accessed three different databases (ERIC, PsycNet, and EBSCOHost) for their review. An iterative process of reviewing and coding the articles led to an in-depth review of 10 recently published articles. Emergent themes resulted from the in-depth review and include information processing, multimedia learning, learning tools and resources, and expert-novice knowledge construction. The reviewed articles also highlight how eye tracking can be used to determine teachers’ engagement with learning material, reading patterns, and sense-making strategies. Additional study characteristics, including context, data sources, eye tracking device and metrics were also reviewed. Results of this review shed light on how educational researchers can effectively use eye tracking methodology to investigate teacher learning at different career stages. This, in turn, can inform educational stakeholders about how to optimize learning opportunities and environments.     

Unique contributions of eye-tracking research to the study of learning with graphics

The author examines the empirical, methodological, theoretical, and practical contributions of the six studies in this special issue on eye tracking as a tool to study and enhance multimedia learning. The design of learning environments involving graphics should be consistent with a research-based theory of how people learn and evidence-based principles of how to help people learn. Research using eye tracking offers a unique path to testing aspects of theories of multimedia learning, particularly concerning perceptual processing during learning. The studies reported in this special issue add to the evidence base on how people learn and think with graphics.     

网络课程学习跟踪评价的实践探索

本文给出"现代教育技术基础"网络课程学习跟踪评价的结构图,以此为实例,结合笔者创建网络课程的经验,重点讨论了网络课程学习跟踪评价的意义、设计原则、实施途径和运行效果.