Low-Power Operational Amplifier for Real-Time Signal Processing System of Micro Air Vehicle

A low-power complementary metal oxide semiconductor(CMOS) operational amplifier (op-amp) for real-time signal processing of micro air vehicle (MAV) is designed in this paper. Traditional folded cascode architecture with positive channel metal oxide semiconductor(PMOS) differential input transistors and sub-threshold technology are applied under the low supply voltage. Simulation results show that this amplifier has significantly low power, while maintaining almost the same gain, bandwidth and other key performances. The power required is only 0.12mW, which is applicable to low-power and low-voltage real-time signal acquisition and processing system.     

高密度PCB对CO_2激光吸收率的应用研究

高密度PCB板的微细孔加工普遍采用激光加工微孔,但PCB板中铜箔对CO2激光的反射率高,会造成铜箔突起和裂纹,能量过小时又无法进行加工,若采用保型掩模加工技术,工艺较复杂.通过光致等离子体分析研究了提高铜箔对激光能量吸收的方法,实验表明:该方法不仅可简化加工步骤,还可进一步提高加工效率.     

OLAP中文本文件建模

在联机分析处理中,由于传统的模型无法对文本文件进行建模,因此提出了基于维概念的星系模型。该模型删除了事实的概念,消除了只能把事实作为分析主题的限制,令联机分析更加自由;而且引入了联系的概念,实现了对文本文件中的超链接进行建模。通过两种方法可以把星型模型中的事实转换成星系模型中的维,实现了星系模型与其他模型之间的转换。     

Clustering-driven watershed adaptive segmentation of bubble image

In order to extract froth morphological feature, a bubble image adaptive segmentation method was proposed. Considering the image’s low contrast and weak froth edges, froth image was coarsely segmented by using fuzzy c means (FCM) algorithm. Through the attributes of size and shape pattern spectrum, the optimal morphological structuring element was determined. According to the optimal parameters, some image noises were removed with an improved area opening and closing by reconstruction operation, which consist of image regional markers, and the bubbles were finely separated from each other by watershed transform. The experimental results show that the structural element can be determined adaptively by shape and size pattern spectrum, and the froth image is segmented accurately. Compared with other froth image segmentation method, the proposed method achieves much high accuracy, based on which, the bubble size and shape features are extracted effectively.     

Monitoring slope deformation using a 3-D laser image scanning system:a case study

An ILRIS-36D 3-D laser image scanning system was used to monitor the Anjialing strip mine slope on Pingshuo in Shanxi province.The basic working principles,performance indexes,features and data collection and processing methods are illustrated.The point cloud results are analyzed in detail.The rescale range analysis method was used to analyze the deformation characteristics of the slope.The results show that the trend of slope displacement is stable and that the degree of landslide danger is low.This work indicates that 3-D laser image scanning can supply multi-parameter,high precision real time data over long distances.These data can be used to study the distortion of the slope quickly and accurately.     

摩擦液柱成形过程的二维CFD数值模拟

采用Gambit软件建立了摩擦液柱成形（FHPP）过程流场的二维轴对称模型,运用商业计算流体动力学软件Fluent对FHPP稳态阶段塑性金属的流动情况进行了数值模拟。通过改变模拟过程中的单一关键参数而保持其他参数不变,分别讨论了金属棒和孔洞之间径向间隙、材料粘度、金属棒转速、金属棒进给速度以及基材孔底形状等对理想金属塑性流体流动成形过程中速度场和压力场分布变化的影响。结果发现,塑性金属材料的压力分布主要受进给速度（即轴向力）和材料粘度的影响,与金属棒的旋转速度和径向间隙关系不大;而速度分布受进给速度以及径向间隙的影响不明显,但与金属棒的旋转速度关系密切,尤其是靠近速度入口面以及金属棒附近的材料受旋转作用影响显著;通过改变基材孔洞底部的形状,可以改善塑性金属材料的流动情况,同时也揭示了实验过程中孔洞底部存在缺陷的原因。     

基于Matlab的数字散斑干涉图像处理

数字散斑干涉技术(DSPI)是一种高精度的光学测量技术,它适用于物体的形变及位移测量。因为其具有较高的测量精度,所以在航空航天、工业检测和生物医学等精度要求较高的领域都得到了广泛的应用。在数字散斑干涉技术中,条纹图像的处理是十分重要的。本文介绍了利用Matlab对散斑图像进行处理的各种方法和实际效果,包括令两幅图灰度值相减得到条纹图,图像的灰度增强处理,滤波处理,二值化处理和条纹的细化处理,最后提取出较清晰的条纹骨架线,为后续处理工作提供了基础。     

运用硬件提高计算全息运算速度综述

计算全息技术的快速发展使得全息电视、全息电影成为可能.许多研究者正在致力于开发的电子全息三维显示系统的最关键的技术之一就是提高计算全息技术的运算速度.由于计算全息技术所需要的计算量很大,使用一般计算机无法以帧频速率实现全息图的计算,因此研究者们在提高全息图的计算速度方面进行了大量的研究工作.在主要调查研究使用硬件加速的方法来提高全息图计算速度的基础上,论述了其研究现状以及未来的发展动态.     

基于人眼视觉特性的遥感图像融合算法

首先提出基于非下采样Contourlet变换(NSCT,Nonsubsampled Contourlet Transform)的人眼视觉相对对比度灵敏度函数(RCSF,relative contrast sensitivity function)和绝对对比度灵敏度函数(ACSF,absolute contrast sensitivity function)。然后提出了基于人眼视觉对比度灵敏度函数(CSF,contrast sensitivityfunction)的遥感图像融合算法(IFA-CSF,image fusion algorithmof human visual contrast sensitivity function)。IFA-CSF采用NSCT作为多尺度变换工具,对单方向高频子带采用ACSF融合,对多方向高频子带采用RCSF融合,并对8方向高频子带采用先方向分组再融合的方法。实验结果表明,IFA-CSF优于基于传统CSF和基于局部能量的图像融合算法。     

狭缝光栅自由立体显示器的立体图像串扰度

为了表征狭缝光栅自由立体显示器存在的左右眼视差图像的混叠程度,提出了立体图像串扰度C的概念。根据狭缝光栅自由立体显示器的结构和工作原理,应用几何光学知识,分析得出了立体图像串扰度C的计算公式,并给出了一个具体的狭缝光栅自由立体显示器的计算结果。通过观看实验,证明了所定义的立体图像串扰度C可以定量描述观看者在立体可视区域看到的立体图像的串扰程度。