雷达辐射源信号识别结果评估方法研究

针对雷达辐射源信号识别结果评价方法杂乱,指标单一等问题,提出一种新的信号识别结果评估体系结构,将识别率测试结果引入到雷达辐射源信号识别结果评估中,构建了基于识别率测试结果的雷达辐射源信号识别结果评估指标体系,建立了评估指标的层次结构模型,应用模糊综合评价法对识别结果进行评估,并对三种识别方法进行了计算机仿真评估实验,验证了新方法的可行性.     

基于粗糙集理论和SVM的雷达辐射源信号快速识别算法研究

本文针对雷达辐射源信号分类指标多、样本数据量大,分类识别实时性不佳问题,提出了一种基于粗糙集理论和SVM的雷达辐射源信号识别算法,算法首先利用粗糙集理论计算出各指标的客观权重,按照综合权重由高到低精简出关键指标。其次对全部指标和精简指标通过不同核函数和优化cost和gamma参数进行SVM识别,仿真结果显示精简指标基本能够达到全部指标的分类性能,90%以上分类准确率都能达到100%,验证了所提算法在样本量较大时能够快速提升识别效能。     

基于脉冲样本图的雷达辐射源识别方法

雷达辐射源识别是雷达对抗侦察信号处理的关键环节。由于现代雷达体制日益复杂,传统的辐射源识别方法面临着越来越严峻的问题。因此针对这种情况,提出了一种基于脉冲样本图雷达辐射源识别算法。这种算法无需对相互叠加的雷达辐射源信号进行完全分选,并且不需要进行传统识别方法中的特征提取过程,简化了处理环节。在脉冲流密度适中的情况下,该算法具有很好的判别准确率。仿真结果验证了该方法的可行性和实用性。     

基于DAGSVM的雷达辐射源信号分选与识别

支持向量机具有较好的解决小样本、非线性问题的能力,而DAG算法具有分类精度高的优点。针对现有方法分选与识别准确率不高和对参数变换敏感的问题,在DAGSVM的基础上,提出一种新的雷达辐射源分选与识别方法。首先概述了支持向量机的原理及特点,然后完成了对SVM多分类器的设计,介绍了DAG算法,提出了基于DAGSVM的雷达辐射源信号分选与识别。并通过仿真实验分析了分类器对分选识别结果的影响。实验结果表明,使用DAGSVM这种方法是可行的,该方法具有较强的泛化性能,明显地提高了信号分选识别的准确性。     

雷达信号识别效果的模糊综合评价研究

雷达辐射源识别是电子对抗情报系统中的关键技术之一,对其识别效果进行科学的评估是一项全新的课题。以往大多数学者评价雷达信号识别方法的好坏主要是比较识别率的高低。针对雷达辐射源识别效果评估指标单一等缺点,选取识别时间、识别率测试结果的均值和方差作为评估指标,将模糊综合评价法引入雷达辐射源识别效果的评估,提出基于模糊综合评价的雷达信号识别效果评估方法,并通过计算机仿真,对三种识别方法进行了评估实验,验证了该方法的可行性。     

基于径向基概率神经网络的雷达辐射源信号识别

雷达辐射源信号识别是电子情报系统和电子支援系统的重要组成部分。文章提出一种基于径向基概率神经网络的雷达辐射源信号识别方法，通过对几种典型雷达辐射源信号复杂度特征提取和采用径向基概率神经网络分类器进行分类识别的实验结果表明，文章所提出的方法是有效的，能在较宽的信噪比范围内获得满意的识别率。     

基于最近邻方法的雷达辐射源信号识别研究

在分析最近邻方法理论的基础上,提出了一种新的雷达辐射源信号识别结构,引入了一种新的距离贴近度度量方式。建立了基于最近邻方法的雷达辐射源信号识别模型,并分别在大样本和小样本数据集合对不同噪声背景下的雷达辐射源正确识别率和识别时间进行了比较分析。仿真表明,基于最近邻的雷达辐射源信号识别方法简单易行,快速简洁,有较高的正确识别率。     

数据库样本缺失下的雷达辐射源识别

目前,基于机器学习的雷达辐射源识别技术大多以训练集和测试集同分布为假设,当雷达数据库样本不足导致与信号真实分布存在偏差时,传统的分类方法效果不佳.为此,将迁移学习理论引入识别系统,设计了一种基于结构发现与再平衡的雷达辐射源信号识别方法.通过对数据库和待识别辐射源信号样本进行聚类分析发现数据结构信息,通过重采样处理修正其分布差异.将新采样数据输入支持向量机进行训练并对侦收样本进行识别.仿真实验表明,在新训练样本集上学习的模型对测试集的分类性能有了很大的提升.     

基于KNN和雷达辐射源脉间参数的舰船目标个体识别方法

针对同型多目标位置接近无法有效区分的问题,提出了一种基于KNN和雷达辐射源脉间参数的舰船目标个体识别方法.根据雷达辐射源脉间参数计算待识别雷达信号与已识别雷达信号的参数关联度,若关联度小于阈值则认为是不同雷达,否则认为是同型雷达则利用最近邻分类算法通过计算待识别雷达目标位置点与已识别雷达目标历史航迹点的距离来判决待识别...     

一种基于脉冲样本图和模糊理论的雷达辐射源识别

在现代信号密集环境中,传统的雷达信号特征描述方式很难对复杂体制雷达辐射源进行描述和识别.因此提出了一种基于脉冲样本图和模糊理论的雷达辐射源识别算法,运用格贴近度的模糊识别算法进行雷达辐射源识别.该方法省略了特征提取过程,简化了处理环节,仿真结果表明,这种方法具有很高的识别准确率.     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.