融合前景判别和圆形搜索的目标跟踪算法

针对运动目标在发生遮挡、形变、旋转和光照等变化时会导致跟踪误差大甚至丢失目标以及传统跟踪算法实时性差的问题,提出了一种融合前景判别和圆形搜索（CS）的目标跟踪算法。该算法采用了图像感知哈希技术来描述与匹配跟踪目标,跟踪过程使用了两种跟踪策略相结合的方法,能够有效地解决上述问题。首先,根据目标运动方向的不确定性和帧间目标运动的缓慢性,通过CS算法搜索当前帧局部（目标周围）最佳匹配位置;然后,采用前景判别PBAS算法搜索当前帧全局最优目标前景;最终,选取两者与目标模板相似度更高者为跟踪结果,并根据匹配阈值判断是否更新目标模板。实验结果表明,所提算法在精度、准确率和实时性上都比MeanShift算法更好,在目标非快速运动时有较好的跟踪优势。     

分导式多弹头的毁伤评估研究

分导式多弹头毁伤效果的评估结果,是作战运用的依据.针对目前国内缺乏用于多弹头毁伤评估的手段和方法,提出了理论计算和Monte-Carlo仿真进行多弹头导弹毁伤效果综合评估的思想.推导了导弹落点系统偏差、落点散布椭圆度和弹头威力对毁伤概率影响的数学表达式,并给出了采用Monte-Carlo方法的具体步骤;两种毁伤效果评估手段相互验证,取得了很好的效果;在各弹头落点散布参数差异较大或威力半径不尽相同的复杂情况下,采用Monte-Carlo仿真进行毁伤效果的评估是一个有效而实用的技术途径.     

中央民族大学信息工程学院，北京100081

分析网络化感知系统节点定位问题的特殊性,针对深空探测环境未知的问题,提出利用全景图像重合度来修正信号衰减模型,提高测距精度;提出一种修正的高精度节点自主定位算法来解决多移动节点协同定位问题,该算法是把切圆法引入到基于全景图片重合度的RSSI修正定位方法中。当多个感知节点定位时,根据视距近似原则选择定位锚节点来进行H-CM算法,仿真结果表明该定位方案可以有效提高感知节点的定位精度。     

Derivation of local software quality metrics (software quality circles)

Software is a product in serious need of quality control technology. Major effort notwithstanding, software engineering has produced few metrics for aspects of software quality that have the potential of being universally applicable. The present paper suggests that, although universal metrics are elusive, metrics that are applicable and useful in a fully defined setting are readily available. A theory is presented that a well-defined software work group can articulate their operational concept of quality and derive useful metrics for that concept and their environment.     

Detecting the wheel pattern of a vehicle using stereo images

This paper presents a method for detecting the wheels of a vehicle in stereo image pairs. The method consists of two steps: (i) geometrical transformation; and (ii) circle extraction. The geometrical transformation uses the disparity values obtained from a stereo image pair to calculate the parameters of the plane containing wheels of the vehicle. By using these parameters, we transform any elliptical wheels contained in the plane to circular ones which can be extracted by the circle extraction algorithm. The circle extraction algorithm consists of (1) template matching and (2) Hough transform. In order to save computation and improve the results in the Hough transform, we employ two constraints (a) the neighbor-region edge connectivity and (b) the gradient direction of each edge point, to eliminate non-circular edge points. Experimental results show that these two constraints do eliminate non-circular edge points and preserve any circle embedded in edges. From the final results, we can observe that our method can detect and locate the wheels of a vehicle successfully.     

生活圈视角下的中小城市公共服务规划对策研究

传统城市规划对公共服务配套重视 不足,一定程度上影响了中小城市公共服务 的完善程度,也对生活圈的构建提出了新的 挑战。本文以重庆市潼南区为例,通过研究 中小城市居民生活的行为特征、对公共服务 的需求以及城市服务配套现状,从生活圈尺 度、边界、设施配套等方面提出了中小城市 公共服务规划对策,以期为生活圈时代的中 小城市公共服务规划提供参考,丰富生活圈 研究内容。     

加工中心切圆的一种异常现象分析

文章介绍了用雷尼绍激光干涉仪对某立式加工中心所切圆进行检验,并对检验图形上坐标反向点处出现的突跳异常进行了分析,结果表明反向点处的突跳异常是由于电动机惯量与移动件移动惯量不匹配所致。     

利用AutoCAD2000绘制三轴剪切线包络线图

介绍了利用AutoCAD2000绘制土工试验三轴剪切线包络线图的作业方法，并结合工程实例对作业过程中的窗口和菜单操作及参数设置等作了具体说明。     

A stable friction compensation scheme for motion control systems

In mechanical positioning control systems, friction phenomenon makes undersirable responses. Friction compensation scheme is frequently implemented to the control system together with the friction estimator in order to cancel the effect of the friction. However, the error in the estimation of the friction results in undercompensation or overcompensation, which also makes undesirable responses. In this paper, a new friction compensation scheme is proposed. The stability analysis is performed based on the circle criterion, which provides a sufficient condition for asymptotic stability of a system. For an application example, the scheme is implemented to a mechanical positioning system of a second-order plant with nonlinear friction. The effectiveness of this scheme is illustrated with the time responses obtained by computer simulation.     

变径基圆渐开线涡旋膨胀机几何及泄漏模型的研究

为分析基圆变化的涡旋型线对膨胀机结构性能的影响,对变径基圆涡旋膨胀机的几何特性进行了探讨.推导了各膨胀腔的容积计算方法;建立了变径基圆涡旋膨胀机的泄漏模型;讨论了不同的基圆变化规律对膨胀机型线的影响,并对其容积和泄漏进行了分析比较,得出了在基圆不断变小所展成的渐开线有较大的容积和较小的泄漏,更加适用于涡旋膨胀机.为变径...