一种时空权重和边缘自适应的扫描格式转换

为实现隔行扫描到逐行扫描的视频扫描格式转换,提出了一种时空权重和边缘自适应的去隔行算法,主要包括运动估计、小角度边缘搜索、时空权重计算、自适应插值等。该算法通过4场相邻像素的最大灰度变化与运动阈值比较实现对当前像素的运动估计,采用自适应搜索半径和并行搜索树的方法实现小角度边缘检测,并且增加对半像素边缘的考虑实现最小6°边缘的检测,最后通过时空权重自适应的插值算法实现去隔行处理,取得很好的处理效果。     

基于增强型边缘定向插值的运动自适应去隔行

为实现隔行扫描到逐行扫描的高质量视频格式转换,提出了一种基于边缘定向插值的运动自适应去隔行算法,主要包括空间加权边缘搜索、边缘定向插值、同极性场间的运动检测和运动自适应插值等。该算法通过增加对边缘的加权拟合和搜索消除伪边缘插值,通过增加边缘方向的预判断抑制反向插值错误,通过边缘搜索的提前终止减小计算量,通过同极性运动检测消除运动检测错误。实验结果表明,基于边缘定向插值的运动自适应去隔行算法在处理图像和视频流时均表现出优异的性能。     

数字电视中高精度运动检测的自适应运动补偿去隔行算法研究

运动自适应算法利用帧间运动信息来选择不同的插补方式实现去隔行，它是一种比较优异的去隔行算法，由于对动态和静态图象都有较好的处理效果，且算法复杂度和硬件占用适当，因此被广泛地应用于数字电视的去隔行电路中。本文针对此，初步探讨了数字电视中高精度运动检测的自适应运动补偿去隔行算法。     

数字电视中视频芯片的自适应去隔行算法研究

文章提出了一种适用于数字电视视频处理芯片上的隔行——逐行格式转换算法。该算法能正确检测出视频的运动和静止信息,从而自适应的采用帧内边缘相关算法或者帧间交织算法进行隔行到逐行的格式转换;并且能准确的检测出并转换具有3-2下拉特征的电影模式视频序列。经仿真验证,该算法与其他算法相比具有占用系统资源少、运算速度快的优点,因此非常适合应用在视频处理芯片中。     

基于分形小波变换的MEMS动态模糊图像亚像素检测技术

基于机器微视觉的微机电系统（MEMS）动态测试系统,提出了一种分形小波变换亚像素检测技术提取MEMS运动轨迹算法.该算法结合电耦合器件（CCD）成像机理,利用图像的分形参数进行随机分形插值对图像边缘进行重建,通过小波变换实现重建后图像亚像素精度的边缘检测.在连续光照明条件下,对MEMS平面微运动模糊图像进行检测处理,提取和分析了MEMS运动轨迹.将该方法和在频闪条件下测得的MEMS器件的平面微运动幅值的结果进行了比对分析和讨论.由实验结果可以看出,本方法有较高的测量精度,其测量绝对误差小于0.02像素.     

空中红外小目标并行分割算法

为提高空中红外小目标检测速度,提出了一种基于灰值形态学序列图像膨胀累加、背景估计和自适应阈值分割的并行结构小目标分割算法。该算法对灰值膨胀运算后的相邻三帧图像进行累加以增强小目标能量;将灰值形态学开、闭运算的平均值作为背景估计图像;采用自适应阈值算法从二者相减的差图像中分割出可能目标;其中小目标能量增强和背景估计采用并行处理结构。基于VisualC 6.0编程进行了实验,结果表明,算法对连续三帧768像素×576像素红外视频采集图像的处理时间为3.73s,较常规串行分割算法快一倍以上。     

面向运动估计器硬件实现的加权块匹配检测算法

在各种视频处理算法中，运动补偿型算法大大提高了各种视频处理效果。运动估计器的硬件实现是各种运动补偿视频处理算法在实际系统中运用的关键。由于块匹配运动估计算法较低的运算复杂度和硬件实现难度以及块匹配检测标准函数很高的调用频率，已经广泛应用到各种实际系统中。文中提出了加权最小最大误差的匹配检测标准，能够降低运动估计器的运算复杂度，减少估计器的硬件面积，提高硬件速度，而且能够降低递归搜索块匹配运动估计算法固有误差传递带来的负面影响。     

光伏电池边缘检测算法研究

为了满足晶硅光伏电池视觉印刷高精度边缘定位要求,本文提出了一种改进的亚像素边缘定位算法.该算法首先应用Sobel算子和线性插值得到边缘垂直方向上新的边缘图像;最后对插值的边缘图像使用改进的灰度矩算子,得到的亚像素边缘.同时本文进行改进亚像素检测算法与传统亚像素检测算法的精度及鲁棒性对比实验.结果表明:本文算法比传统亚像素定位算法有着更好的定位精度和鲁棒性,直线检测精度能达到1μm;在高噪声污染的图像有着较高的检测精度,其标准差为0.195μm.     

一种基于形态学多结构元素的图像边缘检测算法

运用数学形态学的理论和方法,从多结构元素形态学变换的角度出发,利用形态学结构元的自然属性,自适应确定权重,在此基础上采用腐蚀运算构造边缘检测算法,最后将多结构元的检测信息加权求和。实验结果表明,自适应确定权重比平均权重具有更好的图像处理效果,在保持图像边缘清晰的同时,具有很强的去除噪声能力。     

图像插值的改进自适应核回归方法

针对 steering 自适应核回归的插值算法中图像整体灰度值偏离较大和空洞的现象,本文提出了一种基于改进的自适应核回归函数的图像插值算法.该方法根据图像的自相似性原理,通过把图像邻域中像素间几何距离函数融入 steering 自适应核函数中,实现一种改进的自适应核函数,并采用这种核函数对图像进行回归插值.实验结果表明...     

结合EIS和WBE技术研究环氧涂层劣化

为研究环氧涂层在浸泡条件下的失效机理,结合丝束电极(WBE)和电化学阻抗谱(EIS)技术研究了环氧涂层浸泡在天然海水中的劣化过程, 同时分析了与涂层局部缺陷区相对应的电流密度分布和阻抗谱特征的差异．结果表明:丝束电极表面电流密度分布与EIS响应特征能够良好对应,两者结合使用可以实现对表面任意局部阳极和阴极区腐蚀过程的研究;涂层丝束电极的总阻抗响应主要与涂层局部缺陷最为严重处的电极过程特征相对应,而不能反映出其他区域的涂层劣化和涂层下基体的电化学过程信息;涂层下丝束电极出现了极性转换现象,但发生转换的原因各不相同．     

Stochastic penetration of smooth and fractal basin boundaries under noise excitation

Recent work on the escape of a sinusoidally driven oscillator from a universal cubic potential well has elucidated the complex patterns of attractor and basin bifurcations that govern the escape process. Optimal escape, under a minimum forcing magnitude, occurs at a forcing frequency of about 80 per cent of the small-amplitude linear natural frequency, and at this forcing frequency we have identified a significant and dramatic erosion of the safe basin of attraction, triggered by a homoclinic tangency, that would seriously impair the engineering integrity of a practical system long before the final chaotic instability of the constrained attractor. Introducing a superimposed noise excitation, we here quantify this in terms of a stochastic integrity measure, and correlate this with the geometric changes experienced by the deterministic basin of attraction     

Experimental investigation of composite superconductors with high transverse electrical and thermal resistances

The stability of composite superconductors with high electrical and thermal resistances between the superconductor and stabilizing matrix, both in contact with liquid helium, have been studied experimentally using model conductors.The stability to thermal disturbances has been investigated using pulse heaters applied to the superconductor or the stabilizing matrix.The existence of steady state normal regions when the heater is switched off, has been found in the specimen with transverse resistance.The behaviour of specimens with and without transverse resistance under ac conditions at high current charging rates was different. At 50 Hz the quench current of the specimen with transverse resistance proved to be higher than that of the equivalent specimen without the resistance.     

TC1 电阻微焊接接头显微组织及力学性能

目的 研究不同工艺参数（焊接电流、焊接时间）对金属箔材精密电阻微焊接头机械性能的影响。方法 采用电阻微焊接技术对0.05 mm 厚的TC1 箔材进行点焊连接试验,通过拉伸-剪切试验对焊接接头进行力学性能检测,利用硬度网格法结合金相观察,对焊接不同区域进行有效预测。结果 当焊接电流为400 A时,焊核直径随着焊接时间的增加而明显增大,而采用更高的焊接电流时,焊接时间对焊接直径没有显著影响。焊点接头的剪切力随着电流的增大而增大;在所有参数条件下,过长焊接时间都造成了焊点接头剪切力不同程度的减小。此外,由于微观组织的变化,不同焊接区域显现出不同硬度值,其中焊核硬度>母材硬度>热影响区硬度。结论 焊接电流对TC1 电阻微焊接接头力学性能影响较大;硬度网格法可以有效预测焊接不同区域。     

电磁驱动力对金属铸坯凝固的影响

利用低熔点Sn 3.5wt%Pb合金模拟钢的凝固末端电磁搅拌的实验条件,研究了电磁驱动力对铸坯凝固进程的影响。研究表明：在电磁驱动力作用下,半固态区存在一个边界层,边界层表征电磁驱动力作用的极限区域,边界层以内熔体的流速随着搅拌器线圈电流的增大而增大,电磁场对边界层以外的熔体影响不大;电磁搅拌驱动力使固－液界面或边界层向外推移,铸坯凝固坯壳变薄;电磁搅拌力对半固态的金属熔体具有熔蚀、冲刷作用,阻碍柱状晶生长,使凝固壳生长均匀,且内表面光滑无突起。     

Inertial and Fluctuational Effects on the Motion of a Bose Superfluid Vortex

We study the motion of a vortex under the influence of a harmonic force in an approximately two dimensional trapped Bose-condensed gas. The Hall-Vinen-Iordanskii equations, modified to include a fluctuational force and an inertial mass term, are solved for the vortex motion. The mass of the vortex has a strong influence on the time it takes the vortex to escape the trap. Since the vortex mass also depends on the trap size we have an additional dependence on the trap size in the escape time which we compare to the massless case.     

Basin boundary metamorphoses in the canonical escape equation

A study is made of the escape boundary, in the space of the starting values of displacement and velocity, for a sinusoidally driven nonlinear oscillator. The oscillator has constant inertia and linear viscous damping, with a restoring force that corresponds to a cubic potential well. This cubic form of the total potential energy has the universal canonical form encountered by all metastable mechanical systems as they approach a generic fold catastrophe under a single control parameter. The basin boundary metamorphoses are observed, and an engineering integrity diagram is proposed, quantifying the rapid erosion of area that is triggered under increasing excitation by a homoclinic tangency. The pictures show clearly the fractal basin associated with the developed homoclinic tangle. The boundary crisis, at which the final chaotic attractor loses its stability, is examined in terms of an accessible saddle point, which is here a directly unstable subharmonic of order six.     

Basin boundary metamorphoses in the canonical escape equation

A study is made of the escape boundary, in the space of the starting values of displacement and velocity, for a sinusoidally driven nonlinear oscillator. The oscillator has constant inertia and linear viscous damping, with a restoring force that corresponds to a cubic potential well. This cubic form of the total potential energy has the universal canonical form encountered by all metastable mechanical systems as they approach a generic fold catastrophe under a single control parameter. The basin boundary metamorphoses are observed, and an engineering integrity diagram is proposed, quantifying the rapid erosion of area that is triggered under increasing excitation by a homoclinic tangency. The pictures show clearly the fractal basin associated with the developed homoclinic tangle. The boundary crisis, at which the final chaotic attractor loses its stability, is examined in terms of an accessible saddle point, which is here a directly unstable subharmonic of order six.     

Interaction between dislocations and precipitated water bubbles during high temperature creep of quartz

The modes of interaction between dislocations and precipitated water bubbles in quartz are discussed. It is shown that dislocations may be locally anchored by bubbles, but are able to break away under the action of applied stress. To escape, dislocations pinned by bubbles must bow to equilibrium curvature. It was observed that escape via thermal activation alone was not readily possible; however, unpinning of the dislocation through pipe diffusion was found to be possible if the dislocation could drag the bubbles under applied stress. This could result in very small strains leading to a microcreep rate linearly dependent on stress and independent of the concentration of bubbles.     

火灾下紧急逃生的虚拟现实系统开发与评估

在真实环境下进行火灾紧急逃生的研究是非常困难的,这不仅需要花费高昂的费用,同时可能对实验参与人员造成人身伤害。随着计算机技术的发展,虚拟现实系统成为研究人在火灾情况下紧急逃生问题的有效工具。本文研究和开发了一种用于火灾情况下紧急逃生研究的虚拟现实系统。在硬件方面,本系统采用6屏环绕式的成像方式,通过具有特殊设计的旋转座椅与虚拟场景进行交互;在软件方面,本系统实现了火、烟雾、爆炸等视觉效果,以及火警警报、爆炸声、燃烧声等听觉效果。更重要的是,本系统通过烟雾发生器在真实环境下产生烟雾,给用户以真实的嗅觉及视觉刺激,从而营造出更具沉浸性的火灾场景。通过20名用户的主观评价对本系统的使用效度进行评估。本系统可以用于评估建筑物布局,研究火灾中人的行为特征以及评价不同干预方法对火灾逃生效果的影响等。