3维卷积递归神经网络的高光谱图像分类方法

为了针对高光谱图像中空间信息与光谱信息的不同特性进行特征提取，提出一种3维卷积递归神经网络(3-D-CRNN)的高光谱图像分类方法。首先采用3维卷积神经网络提取目标像元的局部空间特征信息，然后利用双向循环神经网络对融合了局部空间信息的光谱数据进行训练，提取空谱联合特征，最后使用Softmax损失函数训练分类器实现分类。3-D-CRNN模型无需对高光谱图像进行复杂的预处理和后处理，可以实现端到端的训练，并且能够充分提取空间与光谱数据中的语义信息。结果表明，与其它基于深度学习的分类方法相比，本文中的方法在Pavia University与Indian Pines数据集上分别取得了99.94%和98.81%的总体分类精度，有效地提高了高光谱图像的分类精度与分类效果。该方法对高光谱图像的特征提取具有一定的启发意义。     

基于主成分分析与局部二值模式的高光谱图像分类北大核心CSCD

提出了两种基于主成分分析与局部二值模式的高光谱图像分类算法。利用主成分分析去除高光谱图像的谱间冗余信息,对降维后的图像利用局部二值模式进行空间纹理特征分析,采用稀疏表示分类和支持向量机分别对提取的特征进行分类。其通过将主成分分析与局部二值模式相结合对高光谱图像进行特征提取,保证了高光谱图像的谱间冗余的有效去除,同时保护了高光谱图像的空间局部邻域信息,因此,此类算法不但能充分挖掘高光谱图像的谱间-空间特征,在较大程度上提高分类精度和Kappa系数,而且在高斯噪声环境中和小样本情况下也具有良好的分类性能。     

基于空谱联合的高光谱图像分类方法现状与展望

高光谱成像技术在近十几年里实现了飞跃式的发展。高光谱图像分类的应用受到广泛关注，其分类精度的提升是当前研究的重点。高光谱图像分类是利用不同地物的诊断性吸收特征区分地物类别。传统的高光谱图像分类仅利用图像的光谱特征，分类效果不明显。近些年的研究表明，同时分析地物光谱特征和空间分布能有效提升分类精度。首先总结了众多空谱联合分类方法，依据空谱信息融合阶段的不同，将空谱联合分类分为预处理的分类、综合处理的分类和后处理的分类，简要介绍了深度学习在空谱联合分类中的实现方法，最后对空谱联合分类的研究前景进行了展望。     

基于多维度特征遥感图像分类方法的研究北大核心CSCD

为了解决传统高光谱图像分类方法精度低、计算成本高及未能充分利用空-谱信息的问题,本文提出一种基于多维度并行卷积神经网络(multidimensional parallel convolutional neural network,3D-2D-1D PCNN)的高光谱图像分类方法。首先,该算法利用不同维度卷积神经网络(convolutional neural network,CNN)提取高光谱图像信息中的空-谱特征、空间特征及光谱特征;之后,采用相同并行卷积层将组合后的空-谱特征、空间特征及光谱特征进行特征融合;最后,通过线性分类器对高光谱图像信息进行精准分类。本文所提方法不仅可以提取高光谱图像中更深层次的空间特征和光谱特征信息,同时能够将光谱图像不同维度的特征进行融合,减小计算成本。在Indian Pines、Pavia Center和Pavia University数据集上对本文算法和4种传统算法进行对比实验,结果表明,本文算法均得到最优结果,分类精度分别达到了99.210%、99.755%和99.770%。     

主动学习高光谱图像分类算法GPU并行计算优化

本文利用高光谱图像的空间-光谱维信息,结合主动学习算法实现高光谱图像分类。该算法利用较少的训练样本获得较高的分类精度,与此同时,该算法的运算过程复杂度高且计算效率非常低。针对这一特点,本文提出了一种利用图像处理器(Graphic processing units,GPUs)对算法进行数据级并行计算优化。并且利用真实场景的高光谱图像对文中提出的并行计算优化方案进行了实验验证,结果表明该方法在保证与串行分类精度一致的情况下,其计算加速比达到34倍左右,验证了基于GPU的高光谱图像分类算法的有效性。     

基于栈式自编码神经网络对高光谱遥感图像分类研究

为了有效利用高光谱遥感图像中的波段信息,提高高光谱遥感图像分类的精确度,本文提出了基于栈式自编码神经网络(Stacked Autoencoder,SA)对高光谱遥感图像进行分类。栈式自编码神经网络充分利用高光谱图像中的光谱信息,对其进行相应特征提取,避免了相邻信息间的相关性和信息的冗余,本方法采用无监督学习和监督学习相结合,既可以像传统方法那样进行降维,简化相关的计算复杂度,同时在分类精度上有很大地提高。     

基于多尺度混合卷积网络的高光谱图像分类

针对高光谱图像数据分布不均匀、空谱特征提取不够充分以及随着网络层数增加而导致的网络退化等问题，提出一种基于多尺度混合卷积网络的高光谱图像分类方法。首先，使用主成分分析对高光谱数据进行降维处理；接着，利用邻域提取将邻域内的像素点作为一个样本，补充相应的空间信息；然后，使用多尺度混合卷积网络对预处理后的样本数据进行特征提取，并加入混合域注意力机制来加强空间和光谱维中有用的信息；最后，使用Softmax分类器对每个像素样本进行类别划分。实验结果表明：将所提出的模型在Indian Pines和Pavia University两个高光谱数据集中进行实验，其总体分类精度、平均分类精度、Kappa系数分别能达到0.987 9、0.983 3、0.986 2和0.999 0、0.996 9、0.998 6。该算法能够更加充分地提取高光谱图像的特征信息，与其他分类方法相比取得了更好的分类效果。     

混合卷积神经网络的高光谱图像分类方法

为了解决高光谱图像领域中,传统卷积神经网络因部分特征信息损失而影响最终地物分类精度的问题,采用一种基于2维和3维的混合卷积神经网络的高光谱图像分类方法,从空间增强、光谱-空间两方面分别进行了特征提取.首先从空间增强角度提出一种3维-2维卷积神经网络混合结构,得到增强后的空间信息;其次从光谱-空间角度利用3维卷积网络结构...     

基于谱域-空域组合核函数的高光谱图像分类技术研究

针对传统高光谱图像分类算法多利用目标的光谱信息,不重视空间信息的问题,本文提出了一种综合利用谱域-空域信息的最小二乘支持向量机分类算法。首先利用主成分分析进行特征提取,然后在保留的主分量图像上用数学形态学得到目标的空域信息。并结合光谱域特征,探讨了各种组合策略,构造组合核函数。通过在分类器中引入空域信息,提高了分类准确率。而且采用了最小二乘支持向量机,将标准向量机的二次规划问题转换为求解线性方程组的问题。利用了其训练速度快、效率高的优点。高光谱数据实验表明,本文提出的方法和单独使用谱域或空域信息进行分类相比表现出了一定的优越性,从而适用于较大规模的高光谱图像分类。      

基于低秩张量分析的高光谱图像降维与分类

提出一种用于高光谱图像降维和分类的分块低秩张量分析方法。该算法以提高分类精度为目标,对图像张量分块进行降维和分类。将高光谱图像分成若干子张量,不仅保存了高光谱图像的三维数据结构,利用了空间与光谱维度的关联性,还充分挖掘了图像局部的空间相关性。与现有的张量分析法相比,这种分块处理方法克服了图像的整体空间相关性较弱以及子空间维度的设定对降维效果的负面影响。只要子空间维度小于子张量维度,所提议的分块算法就能取得较好的降维效果,其分类精度远远高于不分块的算法,从而无需借助原本就不可靠的子空间维度估计法。仿真和真实数据的实验结果表明,所提议分块低秩张量分析算法明显地表现出较好的降维效果,具有较高的分类精度。     

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.