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1.
刘志超  屈百达 《红外与激光工程》2021,50(5):20200309-1-20200309-8
提出基于复数二维经验模态分解(C-BEMD)的合成孔径雷达(SAR)图像目标识别。C-BEMD作为传统BEMD的复数域推广,能直接处理原始SAR图像(包含幅度和相位信息)。采用C-BEMD对原始SAR图像进行分解,获得多层次复数内蕴模函数(BIMF),反映目标时频二维特性。各层次BIMF既有独立描述能力,反映目标不同类型的特征;同时也具有内在关联性,即反映同一目标的固有属性。为此,分类算法基于联合稀疏表示设计,可利用内在关联性约束提高各层次BIMF的表征精度。利用MSTAR数据集中的多类目标SAR图像对方法进行测试验证,结果反映其在标准操作条件(SOC)和扩展操作条件(EOC)均可保持可靠的识别性能。  相似文献   

2.
胡媛媛  韩彦龙 《电光与控制》2021,28(8):40-43,87
针对合成孔径雷达(SAR)图像目标识别问题,提出基于快速自适应二维经验模态分解(FABEMD)的方法.FABEMD可实现对SAR图像的快速分解,获得描述目标低频至高频信息的多层次固态模函数(BIMF).基于结构相似性指标剔除多层次BIMF中的噪声成分,保留高鉴别力部分.分类阶段采用联合稀疏表示对保留的BIMF进行表征分类.基于MSTAR数据集对所提方法进行测试,结果验证了其性能优势.  相似文献   

3.
吴剑波  陆正武  关玉蓉  王庆东  姜国松 《红外与激光工程》2021,50(6):20200531-1-20200531-7
针对合成孔径雷达(synthetic aperture radar,SAR)目标识别问题,提出联合多层次二维压缩感知投影特征的方法。采用二维压缩感知投影作为基础特征提取算法,具有不依赖训练样本、效率高等显著优势。构建多个二维压缩感知投影矩阵提取原始SAR图像的多层次特征。不同投影矩阵获得的特征具有差异性,从不同方面描述SAR图像的灰度分布特性;同时,这些特征源自相同的输入图像,因此也具有一定的内在关联性。采用联合稀疏表示对提取的多个特征矢量进行表征分析,在内在关联性约束下考察不同特征的独立鉴别能力,从而提升每一类特征的稀疏表示精度。最终,根据求解的稀疏表示系数,分别在各个训练类别上对测试样本的多类特征进行重构,获得重构误差。根据最小误差的准则,判定测试样本所属目标类别。通过综合运用多层次二维压缩感知特征提取和联合稀疏表示分类,提高SAR目标识别的整体性能。利用MSTAR数据集中的多类目标SAR图像对方法进行测试验证,结果反映其在标准操作条件(standard operating condition,SOC)和扩展操作条件(extended operating condition,EOC)均可保持可靠的识别性能。  相似文献   

4.
伍友龙 《红外与激光工程》2021,50(4):20200236-1-20200236-7
提出基于多元模态分解的合成孔径雷达(SAR)目标识别方法。多元模态分解是传统模态分解的多元扩展,能够有效避免传统算法中的模态混叠问题。采用多元模态分解对SAR图像进行处理,获得的多层次固有模式函数(IMF)能够更为有效地反映目标的时频特性。不同IMF之间具有良好互补性,同时它们描述同一目标因而具有内在关联性。分类阶段,采用联合稀疏表示对分解得到的IMF进行表征。联合稀疏表示在多任务学习的理念下,对多个关联稀疏表示问题进行求解,可获得更为可靠的估计结果。在获得各层次IMF对应的稀疏表示系数矢量的基础上,计算不同类别对于当前测试样本多层次IMF的重构误差之和,进而判定测试样本的目标类别。基于MSTAR数据集开展实验,通过在标准操作条件、俯仰角差异、噪声干扰以及目标遮挡条件下进行对比分析,验证了提出方法的有效性。  相似文献   

5.
李正伟  黄孝斌  胡尧 《红外与激光工程》2022,51(10):20220029-1-20220029-8
合成孔径雷达(Synthetic aperture radar,SAR)自动目标识别(Automatic target recognition,ATR)是现代战场情报侦察、精确打击的重要支撑技术。为提升SAR ATR整体性能,提出基于二维投影特征多重集典型相关分析(Multiset canonical correlations analysis,MCCA)的方法。首先,采用若干二维随机投影矩阵对SAR图像进行特征提取,获得多层次特征描述。考虑到这些结果之间的相关性和可能存在的冗余及干扰,进一步通过MCCA对它们进行融合处理,获取单一特征矢量。基于稀疏表示分类器(Sparse representation-based classification,SRC)对融合特征矢量进行处理,判决目标类别。实验基于MSTAR数据集开展,对方法性能进行检验确认,结果能够验证其有效性。  相似文献   

6.
特征提取是合成孔径雷达图像目标识别的关键步骤,也是难点之一。该文提出一种基于PGBN(Poisson Gamma Belief Network)模型的SAR图像目标识别方法。PGBN模型作为一种深层贝叶斯生成网络,利用伽马分布具有的高度非线性,从复杂的SAR图像数据中获得了更具结构化的多层特征表示,这种多层特征表示有效提高了SAR图像目标识别性能。为了获得更高的训练效率和识别率,该文进一步采用朴素贝叶斯准则提出了一种对PGBN模型进行分类的方法。实验采用MSTAR的3类目标数据进行了验证,结果表明通过该方法提取的特征有更好的结构信息,对SAR图像目标识别具有较好的性能。  相似文献   

7.
卷积神经网络的出现使得深度学习在视觉领域取得了巨大的成功,并逐渐延伸到合成孔径雷达(SAR)图像识别领域。然而,SAR图像样本量不足,难以支撑卷积神经网络的训练需求,并且SAR图像包含大量相干斑噪声及不确定性,网络结构的设计较为困难。所以,深度学习在SAR图像识别领域的应用受到阻碍。针对上述问题,文中提出一种基于数据扩维的SAR目标识别性能提升方法,通过对原始SAR 图像进行相关预处理操作并把处理后图像与原始图像结合,从而将一维的原始数据扩充成多维数据来作为训练样本。该扩维方法不仅间接扩充了样本量来支撑网络训练,同时也在网络训练前加入了“主动学习冶影响,所以无需针对SAR图像特性来构建复杂卷积网络,而采用成熟、简单的网络进行训练就可以达到理想的测试精度。最后,使用MSTAR 数据对该方法进行了性能验证,实验结果显示了所提方法的有效性。  相似文献   

8.
特征提取是合成孔径雷达(synthetic aperture radar,SAR)目标识别中的关键因素之一.文中提出联合多层次单演谱特征的SAR目标识别方法,采用单演信号对原始SAR图像进行分解,获得不同层次的单演谱成分.基于斯皮尔曼等级相关分析分解的谱成分与原始SAR图像的相关性,设置相似度门限来选取若干具有较强鉴别力的谱成分.采用联合稀疏表示(joint sparse representation,JSR)对筛选得到的谱成分进行表征和分类,并基于MSTAR公开数据集在标准操作条件(standard operating conditions,SOC)和若干扩展操作条件下对多类地面车辆目标进行分类测试.实验结果表明:本文方法在SOC下对10类目标的平均识别率达到98.52%;对30°和45°俯仰角下的10类目标平均识别率分别为98.15%和72.06%;在噪声干扰条件下也可以保持良好的稳健性.综合对比,提出的方法相比现有几类SAR目标识别方法具有一定的性能优势.  相似文献   

9.
针对稀疏表示识别算法在图像域构造冗余字典时过分依赖预处理及原子维数较大的问题,提出基于小波字典的SAR图像稀疏表示识别算法。首先采用二维离散小波变换将原始图像变换到小波域,建立小波域SAR图像特征模型,得出小波域低频成分可充分表征目标类别信息的结论。然后取小波域低频成分进行2DPCA特征抽取构造小波字典,最后由改进OMP算法稀疏分解系数得到识别结果。SAR MSTAR数据的实验结果表明,在无预处理的情况下识别率高达99%,并且在含噪比10%的情况下识别率仍达96%。  相似文献   

10.
针对稀疏表示识别算法在图像域构造冗余字典时过分依赖预处理及原子维数较大的问题,提出基于小波字典的 SAR图像稀疏表示识别算法。首先采用二维离散小波变换将原始图像变换到小波域,建立小波域 SAR图像特征模型,得出小波域低频成分可充分表征目标类别信息的结论。然后取小波域低频成分进行2DPCA特征抽取构造小波字典,最后由改进 OMP 算法稀疏分解系数得到识别结果。SAR MSTAR数据的实验结果表明,在无预处理的情况下识别率高达99%,并且在含噪比10%的情况下识别率仍达96%。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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  相似文献   

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