由粗到精的虹膜图像离焦模糊评价方法

离焦模糊评价在虹膜识别系统中尤为重要。传统的方法是通过频谱分析测量虹膜图像的离焦模糊程度,这类方法容易受到光照变化以及睫毛和眼皮等噪声区域的影响。提出了一种由粗到精的虹膜图像离焦模糊评价方法。第一步,通过频谱分析去除严重模糊的虹膜图像,进行虹膜图像离焦模糊粗分类。第二步,通过方向金字塔分解,提取虹膜图像的质量特征。在人工合成的离焦模糊虹膜图像数据库中,利用径向基神经网络建立起质量特征与质量等级间的对应关系。通过建立起的模型进行实际的虹膜图像离焦模糊等级预测,以及虹膜图像离焦模糊精分类。在Clarkson数据库上的实验结果证明了该方法不仅可以准确区分清晰图像和离焦模糊图像,而且相比于传统的虹膜图像离焦评价方法更接近于人的视觉感知。     

Recent developments in human motion analysis

Visual analysis of human motion is currently one of the most active research topics in computer vision. This strong interest is driven by a wide spectrum of promising applications in many areas such as virtual reality, smart surveillance, perceptual interface, etc. Human motion analysis concerns the detection, tracking and recognition of people, and more generally, the understanding of human behaviors, from image sequences involving humans. This paper provides a comprehensive survey of research on computer-vision-based human motion analysis. The emphasis is on three major issues involved in a general human motion analysis system, namely human detection, tracking and activity understanding. Various methods for each issue are discussed in order to examine the state of the art. Finally, some research challenges and future directions are discussed.     

快速电池检测机反求设计实例分析

反求设计可以在较短时间内设计出符合市场最新要求，性能优于原型的新产品，本文结合快速电池检测机的反求设计实例，阐述反求以获得良好机器性能而不是再现原型为最终目的。具体论述了快速电池检测机反求设计的步骤及其关键参数的选择。     

Automatic gait recognition based on statistical shape analysis

Gait recognition has recently gained significant attention from computer vision researchers. This interest is strongly motivated by the need for automated person identification systems at a distance in visual surveillance and monitoring applications. The paper proposes a simple and efficient automatic gait recognition algorithm using statistical shape analysis. For each image sequence, an improved background subtraction procedure is used to extract moving silhouettes of a walking figure from the background. Temporal changes of the detected silhouettes are then represented as an associated sequence of complex vector configurations in a common coordinate frame, and are further analyzed using the Procrustes shape analysis method to obtain mean shape as gait signature. Supervised pattern classification techniques, based on the full Procrustes distance measure, are adopted for recognition. This method does not directly analyze the dynamics of gait, but implicitly uses the action of walking to capture the structural characteristics of gait, especially the shape cues of body biometrics. The algorithm is tested on a database consisting of 240 sequences from 20 different subjects walking at 3 viewing angles in an outdoor environment. Experimental results are included to demonstrate the encouraging performance of the proposed algorithm.     

Traffic accident prediction using 3-D model-based vehicle tracking

Intelligent visual surveillance for road vehicles is the key to developing autonomous intelligent traffic systems. Recently, traffic incident detection employing computer vision and image processing has attracted much attention. In this paper, a probabilistic model for predicting traffic accidents using three-dimensional (3-D) model-based vehicle tracking is proposed. Sample data including motion trajectories are first obtained by 3-D model-based vehicle tracking. A fuzzy self-organizing neural network algorithm is then applied to learn activity patterns from the sample trajectories. Finally, vehicle activity is predicted by locating and matching each partial trajectory with the learned activity patterns, and the occurrence probability of a traffic accident is determined. Experiments show the effectiveness of the proposed algorithms.     

电网畸变波形的时域分析及补偿

用时域分析的方法将电网的畸变电流分解成与电压波形一致的有功分量和不一致的无功分量。给出了一种采用脉宽调制(PWM)的补偿电流源,补偿其无功分量,消除和抑制．电网波形的畸变．     

建立高职院校学生实践能力培养机制

学生实践能力培养是高等职业教育的重要内涵,学校应从实践能力培养的条件、实践教学管理的机构、实现学生实践能力提高的措施和制度等方面给予保障,才能使学生实践能力的培养和提高真正落在实处。     

独立采空区稳定性研究与经验教训

河台金矿使用类框架结构采空区新型处理技术之后, 近年来在高村与云西矿区产生很多互相独立的采空区, 而2002年其中3个相继发生间壁与顶柱倒塌, 导致围岩片落, 增大了出矿贫化。从理论与实践两方面分析其发生原因以及今后应吸取的教训。