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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
STL、DXF等通用文件格式图形的真实感显示 总被引:6,自引:0,他引:6
以AutoCAD作为图形输入环境,以STL、DXF等格式的图形文件作为数据交换接口,对图形进行交互式立体显示,通过分析文件格式,在Visual C 6.0编程环境下获取文件中的二、三维图形信息,对其中基于回转体的二维图形进行三维旋转造型,生成三维实体数据。并应用OpenGL图形处理技术对输入的三维图形实现真实感显示,进行变换、光照、材质等方面的处理。 相似文献
992.
基于三层网络架构及DOM的XML系统模型 总被引:22,自引:0,他引:22
本文阐述如何在三层网络架构上运用XML以构造XML文档支持系统,提出了基于三层网络架构及DOM的XML系统的模型,该系统与传统的客户/服务器应用或是应用一般的数据传输方式如HTML等系统相比具有减少了网络流量、更有利于检索、可从多种不同的数据源集成数据、开放性、可扩充性、可重用性等一系列特点。 相似文献
993.
SGCMG系统框架角轨迹跟踪自适应补偿控制 总被引:5,自引:1,他引:4
作为应用在航天器上的惯性执行机构,单框架控制力矩陀螺(GSGCMG)系统框架角空间的轨迹跟踪性能对航天器姿态控制(或稳定)精度有着极大的影响,为提高SGCMG系统框架角轨迹跟踪性能,本文在轨迹跟踪控制中,采用了“PD+自适应补偿”的控制器结构,通过分析可以发现,此种控制器不但可使轨迹跟踪误差收敛至零,实现有限时间跟踪控制,而且可使轨迹跟踪误差每一分量的绝对值指数收敛,对应用在航天器上的金宁塔形4-SGCMG系统框架角空间轨迹跟踪控制的仿真结果表明,上述控制算法是可行的。 相似文献
994.
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
995.
N.?U.?Ahmed C.?D.?CharalambousEmail author 《Mathematics of Control, Signals, and Systems (MCSS)》2007,19(1):65-91
In this paper, we consider minimax games for stochastic uncertain systems with the pay-off being a nonlinear functional of
the uncertain measure where the uncertainty is measured in terms of relative entropy between the uncertain and the nominal
measure. The maximizing player is the uncertain measure, while the minimizer is the control which induces a nominal measure.
Existence and uniqueness of minimax solutions are derived on suitable spaces of measures. Several examples are presented illustrating
the results. Subsequently, the results are also applied to controlled stochastic differential equations on Hilbert spaces.
Based on infinite dimensional extension of Girsanov’s measure transformation, martingale solutions are used in establishing
existence and uniqueness of minimax strategies. Moreover, some basic properties of the relative entropy of measures on infinite
dimensional spaces are presented and then applied to uncertain systems described by a stochastic differential inclusion on
Hilbert space. An explicit expression for the worst case measure representing the maximizing player (adversary) is found. 相似文献
996.
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: |
997.
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: |
998.
999.
动态滑模控制及其在移动机器人输出跟踪中的应用 总被引:11,自引:0,他引:11
针对轮式移动机器人的输出跟踪问题,提出一种动态滑模控制方法,首先给出机器人的动力学简化模型,然后将其分解成两个低阶子系统,并给出其输出跟踪的动态滑模控制器设计方法,仿真试验表明该方法能明显地削弱滑模控制系统的抖振。 相似文献
1000.
降维网络及其在混凝土配合比优化设计中的应用 总被引:6,自引:2,他引:4
提出在BP网络的输入层与隐层或径基函数网络的输入层与隐层之间增加一个只有2个结点的线性函数层(Z层),以构成基于BP网和基于径基函数网的降维映射网络,这两种网络均将多维输出Y(可为一维)与多维输入X之间的非线性映射关系转变成与二 维向量Z之间的非线性映射关系,网络学习后,就可以在由Z构成的二维映射平面上描绘出输出向量的等值线,通过这些等值线可全景式地,准确可靠地出样本数据集的最估操作区域,实现混凝土配合比优化设计。 相似文献