电子散斑干涉图样及其模拟／数字混合处理

本文建立了一个电子散斑干涉系统,并将其产生的干涉图样进行模拟/数字混合处理。这种方法将数字图像处理技术应用干电子散斑干涉测量,使之与传统的模拟信号处理技术相结合,有效地改善了电子散斑干涉条纹图像质量,提高了测量精度。实验测量了几种物体的离面形变,而内位移和简谐振动并给出了一些实验结果。     

动态主观散斑的时间相关性研究

根据散射屏移动时动态主观散斑时间相关公式,分析了成像系统主要参数对动态主观散斑时间相关性的影响：一般情况下屏表面参数对散斑的时间相关性影响较小;激光光斑大于成像系统物面分辨斑时,散斑的时间相关性由透镜孔径大小决定;激光光斑小于成像系统物面分辨斑的尺寸时,减小激光光斑尺寸能减弱散斑时间相关性。对于以上结果进行了相关的理论模拟和部分实验验证,通过模拟发现,激光光斑小于成像系统物面分辨斑时,散斑时间相关长度和光斑尺寸大小成正比。结论对于激光投影系统中利用时间平均进行的散斑抑制具有指导意义。     

弱散射产生的远场高斯散斑场的动态特性

本文计算了三种不同表面相关下弱散射体平动时,散斑强度涨落的时-空交叉相关系数;用“非圆型度”和“束比”参数与交叉相关系数的关系,讨论了远场高斯散斑场的动态特性;提出了一种测量弱散射体运动速度的方法。     

计算机辅助散斑干涉法的研究与改进

针对传统的加法模式的计算机辅助散斑干涉法抗噪声能力弱、信噪比低的缺点,提出了一种减法模式的计算机辅助散斑干涉法.实验上对强度型加、减法模式的计算机辅助散斑干涉法和振幅型加、减法模式的计算机辅助散斑干涉法做了比较分析,最后发现振幅型减法模式的计算机辅助散斑干涉法抗噪声能力最强,信噪比最高,测量精度极其精确.因此一般选择用振幅型减法模式的计算机辅助散斑干涉法来进行物体的变形测量.     

植物果实的激光动态散斑

首次将激光动态散斑相关技术用于植物果实表面细胞粒子运动的测量，观察到一些有意义的现象，本文对此进行了试探性解释，其生物学上的重要意义的特进一步研究。     

植物果实的激光动态散斑

首次将激光动态散斑相关技术用于植物果实表面细胞粒子运动的测量，观察到一些有意义的现象，本文对此进行了试探性解释，其生物学上的重要意义有待进一步研究．     

平板玻璃微小楔角的散斑法测量

本文提出了一种检验平板玻璃微小楔角的新实验方法。它利用激光散斑技术,记录了由于微小楔角引起的散斑位移量的散斑图,由此导出被测试件的微小楔角。这种方法具有光路简单、非接触、精度高等特点。到目前为止,尚未见有这方面的具体报导。     

透明介质厚度的散斑法测量

本文提出了用激光散斑技术测量透明介质厚度的方法,导出了试件厚度与散斑位移的关系式,并进行了比较实验和误差分析。     

动态散斑的统计理论和应用

推导了由运动的散射体产生的动态散斑的强度起伏的互相关函数，提出照明光源的曲率中心经光学系统的成像面即为动态散斑的纯沸腾面，由此给出了透镜的焦距、照明光的曲率中心、散射体的运动速度等的测量方法。     

动态散斑用于确定高斯光束曲率中心位置

本文通过推导高斯光束照明的毛玻璃产生的散斑的互相关函数,得出此光源的曲率中心经光学系统的成像面为激光动态散斑的纯沸腾面。由此给出确定高斯光束曲率中心位置的方法。     

一个实用化的机载SAR实时成像处理系统和在其他信号处理中的应用

该文详细介绍了一个实用化的机载SAR高分辨率实时成像处理系统的信号处理流程,体系结构以及该系统在其他信号处理领域应用可能性的探讨。由于采用了通用总线,微处理器和DSP芯片,以及通用的操作系统,使得该信号处理系统实现了模块的标准化和开发的软件化,具有良好的应用前景。     

多曝光斑纹及用作测速研究

双曝光斑纹照相可以测量位移、转动、振动等力学参数,但多曝光斑纹照相应该可以提高斑纹照片所产生的干涉条纹的锐度,并可以扩大测量范围,在这方面进行研究的人较少。我们分别做了面内位移为20微米的2次、3次、4次……80次以至120次的多曝光斑纹照相,测出2、4、9、14、40、80、120次曝光的斑纹照片产生的干涉条纹的黑度曲线,作出了亮条纹半宽度与暗条纹半宽度的比值跟曝光次数的关系曲线,从而证实了多曝光斑纹可提高干涉条纹的锐度的论点。但从曲线中又发现了新现象,当曝光次数增大时,亮条纹与暗条纹半宽度的比值虽然逐步减少,但当次数近100次时,变化值不大,曲线变得平缓。究其原因,是由于曝光次数     

VMOS technology applied to dynamic RAMs

A seven-mask VMOS process has been developed for dynamic RAMs with self-aligned VMOS and planar Al-gate transistors. Using 4 /spl mu/m photolithography, one-transistor cells with a cell size of 150 /spl mu/m/SUP 2/ have been realized. The read signal at the bit line is more than 200 mV. Implementations of a sense amplifier and a word-line driver show that those circuits determine the smallest word and bit line spacing. The paper is concluded by a proposal for a 64K RAM with a chip size of 21 mm/SUP 2/ using 4 /spl mu/m design rules.     

Bayesian model selection applied to spatial signal processing

Inference is applied to the problem of direction of arrival estimation and the determination of the number of sources present in the case of signals impinging on a linear array of sensors. The method is discussed, and the algorithm is found to outperform methods such as AIC and MDL even in the case of very low signal-to-noise ratios and closely spaced sources. The two levels of inference involved in any data analysis problem are introduced and this inference methodology, using the concept of evidence, is then applied to this problem. Simulation results illustrate the power of the method and it is shown that one of the advantages of the present approach is that it is able to handle special cases such as coherent and correlated signals of any functional form, and it does not assume the receivers to be equally spaced     

Blockwise processing applied to brain microvascular network study

The study of cerebral microvascular networks requires high-resolution images. However, to obtain statistically relevant results, a large area of the brain (several square millimeters) must be analyzed. This leads us to consider huge images, too large to be loaded and processed at once in the memory of a standard computer. To consider a large area, a compact representation of the vessels is required. The medial axis is the preferred tool for this application. To extract it, a dedicated skeletonization algorithm is proposed. Numerous approaches already exist which focus on computational efficiency. However, they all implicitly assume that the image can be completely processed in the computer memory, which is not realistic with the large images considered here. We present in this paper a skeletonization algorithm that processes data locally (in subimages) while preserving global properties (i.e., homotopy). We then show some results obtained on a mosaic of three-dimensional images acquired by confocal microscopy.     

Backward and forward linear prediction applied to ultraspectral image processing

Atmospheric infrared sounder images are ultraspectral data cubes that comprise over two thousand spectral bands accounting for well over 25 megapixels of information. In this paper, we focus on the analysis of backward and forward linear prediction (LP) applied in the context of ultraspectral image compression. We start by introducing a detailed analysis of the differences and similarities between them and proceed to present a mathematical model that integrates not only error signal but also LP coefficient encoding. In addition, to overcome some of the limitations of backward LP, we present a hybrid LP scheme where both, backward and forward LP, are put into consideration by dynamically interleaving them in order to minimize the mean square error of the error signal. The model is further extended to compare all three techniques, and both experimental and theoretical samples are contrasted to verify that hybrid LP provides most efficient compression method.     

Adaptive and vector directional processing applied to video colour images

The adapted K-nearest neighbour and adaptive vector median filters together with vector directional processing to filter 3D images are presented. Vector median, median and adaptive vector median filters have been modified and proved to suppress impulsive noise in the video sequences.     

激光散斑验光仪及其应用研究

给出利用激光散斑测定人眼屈光不正的理论依据和有关公式,详细介绍了激光散斑验光仪的光路系统和主要特点以及临床应用研究的结果。     

实时数字散斑干涉仪及其应用

介绍了一种用于工程的多功能数字散斑干涉仪的测量原理、系统结构和设计特点，并给出了测量结果。