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991.
The Lorenz system is well known for its ability to produce chaotic motion and the control problem of this system has attracted much attention in recent years. In this paper, control of the Lorenz chaotic systems based on a nonlinear feedback technique is presented. The objective of control is two-fold: one is to drive the system to one of equilibrium points associated with uncontrolled chaotic motion and the other is to let one of the closed-loop system states track a given signal. The controllers designed here are based on exact linearization theory of nonlinear systems and can regulate the closed-loop system states globally to a given point. Finally, illustrative examples show the effectiveness of the proposed design method. 相似文献
992.
目前音频数据库的研究相对于图象处于滞后,文中侧重音乐角度,结合MPEG标准和基于内容检索的应用,综述了音频检索的研究现状,分析了音频方面研究的特殊性和相关应用中的问题;并提出基于独立分量分析(ICA)的按调查询(QBH)的系统,较好地解决了特征提取中的鸡尾酒会效应问题。系统的查询结果置于三维声效环境中加速了查询。 相似文献
993.
Detection and Tracking of Multiple,Partially Occluded Humans by Bayesian Combination of Edgelet based Part Detectors 总被引:6,自引:1,他引:5
Detection and tracking of humans in video streams is important for many applications. We present an approach to automatically
detect and track multiple, possibly partially occluded humans in a walking or standing pose from a single camera, which may
be stationary or moving. A human body is represented as an assembly of body parts. Part detectors are learned by boosting
a number of weak classifiers which are based on edgelet features. Responses of part detectors are combined to form a joint likelihood model that includes an analysis of possible
occlusions. The combined detection responses and the part detection responses provide the observations used for tracking.
Trajectory initialization and termination are both automatic and rely on the confidences computed from the detection responses.
An object is tracked by data association and meanshift methods. Our system can track humans with both inter-object and scene
occlusions with static or non-static backgrounds. Evaluation results on a number of images and videos and comparisons with
some previous methods are given.
Electronic Supplementary Material Supplementary material is available in the online version of this article at 相似文献
994.
Zoom tracking is becoming a standard feature in digital still cameras (DSCs). It involves keeping an object of interest in
focus during the zooming-in or zooming-out operation. Zoom tracking is normally achieved by moving the focus motor in real-time
according to the so-called trace curves in response to changes in the zoom motor position. A trace curve denotes in-focus
motor positions versus zoom motor positions for a specific object distance. A zoom tracking approach is characterized by the
way these trace curves are estimated and followed. In this paper, a new zoom tracking approach, named predictive zoom tracking
(PZT), is introduced based on two prediction models: auto-regressive and recurrent neural network. The performance of this
approach is compared with the existing zoom tracking approaches commonly used in DSCs. The real-time implementation results
obtained on an actual digital camera platform indicate that the developed PZT approach not only achieves higher tracking accuracies
but also effectively addresses the key challenge of zoom tracking, namely the one-to-many mapping problem.
相似文献
V. PeddigariEmail: Email: |
995.
Detecting and tracking human faces in video sequences is useful in a number of applications such as gesture recognition and
human-machine interaction. In this paper, we show that online appearance models (holistic approaches) can be used for simultaneously
tracking the head, the lips, the eyebrows, and the eyelids in monocular video sequences. Unlike previous approaches to eyelid
tracking, we show that the online appearance models can be used for this purpose. Neither color information nor intensity
edges are used by our proposed approach. More precisely, we show how the classical appearance-based trackers can be upgraded
in order to deal with fast eyelid movements. The proposed eyelid tracking is made robust by avoiding eye feature extraction.
Experiments on real videos show the usefulness of the proposed tracking schemes as well as their enhancement to our previous
approach.
相似文献
Javier OrozcoEmail: |
996.
997.
MAO Wei ZHENG Fengtian MAO Jia School of Agricultural Economics Rural Development College of Transportation Renmin University of China Jilin University Beijing China Changchun Jilin Province China 《International Journal of Industrial Ergonomics》2006,(1)
I. INTRODUCTION Along with the economical rapid development and the living standard unceasing enhancement, the consumer request to food quality in a new stair, food consumption pattern has assumed multiplex development tendency, food demand pattern transforms into "the multi- varieties, guarantees safety". Food no longer only is essential item which satisfies life needs; the consumer attention to food from the quantity moves towards the credit level, food security problem appears. How doe… 相似文献
998.
本文介绍了一种优化图像数据库性能的算法-边界描迹算法,通过形态学变换减少笔迹图像的孤立点噪声,采用边界描迹的方法提取图像的基本特征,并以链码形成存储图像数据。可以大大减少图像数据的存储量,本文详细阐述了此方法的算法实现。 相似文献
999.
1000.
引大入秦工程总干渠先明峡倒虹吸管水平段钢管因温度变化引起上下游伸缩节的预留伸缩量发生了较大的变化,造成支承环的底座与支墩上的四氟滑块产生了较大错位,支墩出现了偏心受压,大部分四氟滑块出现断裂、脱胶和翘曲等破坏。通过水平管段支承环底座的摩阻力、伸缩节橡胶棒摩阻力计算,水平管段采用箱型定向滑动导轨和滑动钢球的复位措施、施工方法、步骤。采用该施工方法复位后,工程运行情况良好。 相似文献