基于异面交会模型的立体视觉像机站位优化研究

高精度的摄影测量中,双目视觉测量是一种高效可行的测量方法。为了研究测量中双像机位置关系对测量结果的影响,将像机标定、定向及图像坐标提取等干扰因素作为理想量来考虑,从双像机交会测量的数学模型出发,综合双像机光轴的交会角、像机视场角以及红外发光二极管(LED)的发光角等方面因素,通过分析双像机在不同位置关系下对测量区域中红外LED控制点进行测量的结果及精度,最终给出双目视觉测量中像机站位的优化策略。     

会聚光路中别汉棱镜的位置误差对系统像跳影响的分析

本文针对别汉棱镜在系统的加工装调过程中,由于别汉棱镜的位置误差带来系统的光轴失调,引起像跳,直接影响系统瞄准精度问题,从理论上分析了各种误差因素对系统光轴的影响及计算公式,同时,根据实践经验给出了控制光轴失调应有的结构设计和装调工艺方法。     

光轴位置及腔镜变形对多折腔输出特性的影响

本文研究在高功率横流CO2激光器多折腔中,影响光轴位置的几个因素及对输出特性的影响,并用实验方法确定了多折腔的最佳光轴位置。研究了多折腔中反射镜产生形变的原因,并从谐振腔参数出发,找到了克服这类腔型反射镜形变对输出特性影响的措施。     

LED视角亮度关系及其对显示屏亮度均匀性的影响分析

LED显示屏的均匀性有诸多因素决定,其中亮度均匀性是影响视觉效果的最主要因素。在分析亮度均匀性的过程中发现,LED管发光特性所决定的其在沿光轴方向上光强最强,沿发光面向四周光强逐渐减弱,因此,以LED管为基本像素构成的LED显示屏在法线方向上的亮度也最高,当偏离法线方向时亮度会不同程度的降低,这样由于LED管的性能参数及制造工艺等的影响使LED显示屏出现麻点、马赛克等亮度不均匀现象。本文以LED单管和单元箱体为研究对象,通过实验得出了LED视角与亮度的变化关系,深入分析了影响LED显示屏亮度均匀性的原因,并对亮度数据的采集方法以及生产过程中须注意的问题提出了相关建议。     

斜光轴数字图像相关法动态位移测量研究

定量分析了远距离斜光轴成像位置变化对数字图像相关方法产生的影响,提出使用参考测量技术克服斜光轴成像的不利因素,给出一种新的斜光轴高精度测量动态面内位移的方法,在2-50m处测量最大相对误差小于1%,该方法具有无需共轴光路的测量环境要求的特点。通过C 开发了测量软件系统,运用Windows下新的图像采集和序列图像相关方法,并内嵌Matlab引擎快速给出动载特性测量数据和曲线,特别适用于桥梁、高速公路立交桥的动载特性测量等工程应用。     

基于WMPS的多光谱光轴平行性检测系统设计

设计了一种新型多光谱多光轴武器装备通用化的光轴平行性检校系统。采用高精度平移平行光管的方法,使平行光管出射的平行光束分别进入武器平台各个光电系统,由平行光管产生无限远白光、微光、红外目标,对待检测多光轴武器系统进行光轴平行性检测。利用WMPS单发射站测角模型,结合摄影测量PNP问题,建立高精度空间坐标定位系统,对平行光管在移动过程中进行精准位置姿态测量,并根据测量结果进行高精度姿态恢复,保证平行光管平移精度。该系统能够适用于多种不同类型光电武器装备,实现自动化检测,并给出了数字化光轴误差量,具有良好的通用性和可扩展性。     

红外点源目标光轴测试技术

为了测量红外点源目标模拟器光轴相对五轴飞行仿真转台的三轴转台内框中心轴的偏差,建立了以转台内框中心轴为基准测试红外点源目标模拟器光轴位置的理论模型,分析了系统误差类型和测试原理,并设计了一套实验装置对红外点源目标模拟器光轴进行测试。该实验装置固定在三轴转台内框上,测量出红外点源目标模拟器光轴相对于转台内框中心轴偏离的角度,完成了目标光轴相对于转台内框中心轴的测试。实验装置测量角分辨率为0.2′,实验中测得目标光轴与转台内框中心轴的角偏差为1.0′。     

低照度双目立体显著目标距离测定方法与实现

针对位置已固定的双目立体装置,提出了一种基于非平行模式测距原理的双目系统光轴-光心参数标定方法,减小了光轴-光心位置误测量带来的测距误差;为解决低照度下双目立体视觉中存在的立体匹配误匹配点多、目标识别度低的问题,采取了最大熵法结合整体光强变化的阈值选取方法提取显著目标,提高了目标识别率,搭建了显著目标测距系统.结果表明:采用文中的系统标定与阈值选取方法的双目立体视觉装置在低照度下具有较高的测距精度及目标识别率.     

基于红外图像能量值的自动聚焦算法

自动聚焦的关键在于图像的评价函数,介绍了几种传统的评价函数,并比较这几种函数评价图像清晰度的优劣。采用红外图像的能量值作为评价函数的输入值,大大节省了计算时间,评价准确度高。利用单片机控制步进电机并记录转动步数,驱动镜头的光轴转动,将光轴从一个极限位置转动到另一个极限位置,找到评价值最高的位置,能够快速完成自动聚焦。     

斜光轴数字图像相关法动态位移测量研究

定量分析了远距离斜光轴成像位置变化对数字图像相关方法产生的影响，提出使用参考测量技术克服斜光轴成像的不利因素，给出一种新的斜光轴高精度测量动态面内位移的方法，在2—50m处测量最大相对误差小于1％，该方法具有无需共轴光路的测量环境要求的特点。通过C 开发了测量软件系统，运用Windows下新的图像采集和序列图像相关方法，并内嵌Matlab引擎快速给出动载特性测量数据和曲线，特别适用于桥梁、高速公路立交桥的动载特性测量等工程应用。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks