优化的RBF神经网络对光纤位移传感器温度补偿

在对光纤位移传感器进行温度标定的过程中,随着工作环境的变化,位移传感器的测量值会产生误差,从而使位移传感器在使用时随着环境温度的变化发生精度下降的情况。为减少这种漂移偏差,该文使用径向基(RBF)神经网络对位移传感器进行温度补偿,并采用自适应的设计思想寻找RBF函数中心。将位移量和环境温度作为输入,其输出为传感器输出电压,使用自适应的设计思想来确定基函数的中心,建立一个基于RBF神经网络的模型。结果表明,该模型的训练结果可以使光纤位移传感器进行测量的相对误差降低9.23%,在测量精度上有很大的改进,证明了该方法的可行性。     

基于光纤传感器的元件表面粗糙度测量方法

元件表面粗糙度属于机械加工中体现元件表面微观形态的核心参数,提出基于光纤传感器的元件表面粗糙度测量方法,根据定位装置变换光纤传感器探头中定位与距离,光源传输的光纤以光纤束的形式直射到元件上,经元件表面轮廓调节后出现反射与散射,部分光纤经过接收光纤束与光电转换变成光纤传感器测量信号;为了去除光源光强干扰,通过补偿电路增大光纤传感器测量信号的完整性,通过完整的光纤传感器测量信号准确获取元件表面原始轮廓信号,再采用FIR滤波器去除光纤传感器所获取的元件表面原始轮廓信号中的噪声;并将降噪后的元件表面原始轮廓信号传输至单片机,单片机采用光学散射法计算元件表面微观粗糙度,获取光传感器测量的元件表面粗糙度信息。经验证,针对不同粗糙程度的元件表面,所提方法均可准确测量元件表面的粗糙度。     

光纤端面处理对光纤激光器输出性能的影响

从光纤端面的不同处理方法(抛磨法、切割法)入手,对各自工艺展开了较深入的探索,测试了经不同方法处理后光纤端面的表面粗糙度:抛磨端面的表面粗糙度达到0.6nm,切割端面的表面粗糙度为24nm.研究了不同端面处理方法对光纤激光器输出性能(输出功率、光束质量)的影响.     

宽量程反射式光纤位移传感器的研究

分析了反射式光纤位移传感器的输出特性,设计了一种新的宽量程反射式光纤位移传感器。以传感器的输出及其相对应的实际位移训练神经网络,建立基于神经网络的传感器逆模型,将其用于传感器输出信号的处理,扩大了测量范围和提高了测量精度。     

强调原始创新,突出成果转化——贺《军医进修学院学报》创刊30周年

针对某型捷联惯导系统中光纤陀螺仪的输出信号随温度漂移严重的问题,使用径向基函数(RBF)神经网络建立温度补偿模型.神经网络的结构为输入层和输出层各有一个节点,中间隐层含有4个节点,隐层节点的聚类中心均匀分布在温度的变化范围之内.实验结果表明,该方法可有效地将光纤陀螺仪中的温漂误差减小1个数量级以上,补偿效果明显.     

光纤电压传感器的温度跟踪补偿

分析了光纤电压传感器的温度特性 ,表明测量范围较宽时 ,传感器的输出易受环境温度的影响 ,并且呈非线性。提出一种基于人工神经网络的光纤电压传感器温度跟踪补偿方法。利用神经网络具有逼近任意非线性函数的特点 ,通过训练使神经网络建立在不同环境温度下传感器输出与其实际感受的电压值之间的非线性映射关系 ,实现光纤电压传感器温度全程跟踪补偿。计算机仿真表明 ,该方法不仅能有效地消除温度的影响 ,而且能在神经网络的输出端得到期望的线性输出。     

基于双D型光纤表面等离子共振折射率传感研究

以双D型光纤作为传输载体,研究了一种基于表面等离子共振技术的双D型光纤折射率传感器。利用时域有限差分法,分析了双D型光纤剩余包层厚度、金膜厚度、金膜表面粗糙度以及双通道传输对光纤SPR传感器性能的影响。仿真结果表明,当剩余包层厚度为300~500nm、覆盖的金膜厚度为50nm时,双D型光纤SPR传感器的性能得到优化;金膜表面粗糙度也是影响传感器性能的重要因素,当金膜表面粗糙度的均方根值低于2nm或其相关长度大于160nm时,金膜表面粗糙度对传感器性能的影响显著减小,且在折射率为1.33~1.36的传感环境下具有较好的线性度;在双D型光纤两侧覆不同的金属膜,可以实现信号的双通道测量。     

上海激光所与硅酸盐所合作研制成功光纤激光器

光纤激光器将成为新一代光纤通讯中的信号放大系统以及作为灵敏的传感器方面的应用,为国内外学者所关注。上海激光所与硅酸盐研究所合作研究光纤激光器已取得了第一阶段的结果,获得了掺钕光纤激光器及超荧光光纤激光,输出波长为1.08nm,结构简单,运转可靠,重复性     

单片机在表面粗糙度测量系统中的应用

设计了一种以单片机和光纤传感器为基础构成的表面粗糙度测量系统。该系统由光纤传感器、信号检测电路、单片机处理电路和显示装置组成。其特点是系统性能稳定、适应性强、精度高,可以对不同加工方法的工件实现非接触和在线测量。重点给出了该系统的主要硬件和软件及实现方法。     

二频机抖激光陀螺漂移数据滤波方法

为了有效抑制二频机抖激光陀螺(RLG)输出数据中的随机漂移,提出了一种结合谐波小波预滤波进行网络训练的径向基函数(RBF)神经网络滤波方法.原始的陀螺输出经过谐波小波预滤波消噪.消噪后的数据作为RBF神经网络训练样本的期望输出,对神经网络进行训练.以实测的长时间陀螺输出对完成训练的RBF神经网络的有效性进行验证,并利用...     

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.     

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.     

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.     

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.     

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.     

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.     

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