基于K-均值聚类和势函数法的欠定盲分离

K-均值聚类法能估计出观测信号聚类直线方向,利用主成分分析(PCA)提取主成分,可以提高直线估计的精准度和鲁棒性.在此思想的指导下,本文提出基于K-均值聚类的势函数法.势函数度量了聚类中心与所有观测点的距离,对势函数求导得到更新聚类中心的迭代公式,利用该公式对K-均值聚类法得到的聚类中心进行调整得到精估计.该算法计算量较小,能有效估计出混合矩阵.仿真实验验证了算法的有效性.     

一种改进的核可能性C-均值聚类图像分割算法

可能性C-均值聚类(PCM)算法比传统模糊C-均值聚类算法具有更好的鲁棒性,但其应用于图像分割时没有充分考虑图像的局部空间信息。基于PCM算法,提出一种核空间与自适应中值滤波相结合的改进算法。算法利用自适应中值滤波获得像素的局部空间信息,并由此生成一种新的模糊因子加入到目标函数中,然后在核空间中对目标函数进行优化求解,得到最优聚类中心和隶属度。由实验结果可知,所提算法对被高椒盐噪声污染的图像具有较高的准确性和鲁棒性。     

网络推荐系统中K-均值聚类算法的研究及优化

研究了聚类分析技术在网络推荐系统中的应用。由于k均值(k-means)聚类算法易受到局部最优与噪声点等因素的影响,文章结合DBSCAN(Density-based Spatial Clustering of Application with Noise)算法和MMD(Max-Min Distance)初始聚类中心选取算法,对原始k-means算法进行了改进,提出了DMK(Density-based and Max-min-distance K-means)算法。该算法使用DBSCAN选取高密度点作为第一个聚类中心点的备选范围,接着选择相距最远的K-1个点作为其余的K-1个聚类中心,然后用得到的这组初始聚类中心进行k-means聚类。仿真与实验结果表明,该算法选择的初始聚类中心比较分散且代表性好,聚类的迭代次数减少,聚类结果的纯度提高。     

基于空间信息的模糊C-均值噪声图像分割算法

针对传统模糊C-均值(Fuzzy C-means, FCM)聚类算法对噪声鲁棒性差的问题,提出一种基于空间信息的模糊C-均值噪声图像分割算法。将区域级信息加入FCM目标函数中,并用核度量方法代替传统欧氏距离,计算区域级空间信息与聚类中心的距离,提高算法对噪声的鲁棒性;用原始图像与区域级空间信息的绝对差的倒数和其本身约束原始图像和区域信息项,实现约束项参数的自适应选择;利用连通分量滤波,消除聚类结果中出现的过分割现象,提高分割精度。含噪合成图像和彩色图像实验表明,所提算法在模糊分割系数、模糊分割熵、分割精确度、平均交互比和归一化互信息等方面均优于其他几种聚类算法。     

核空间自适应非局部均值鲁棒分割算法

为改善传统模糊C均值(FCM)算 法对噪声干扰下图像的分割效果,提出了一种基于核空间邻域信息和自适应非局部均值相结 合的图像鲁棒分割算法。首先,利用传统FCM聚类算法进行初始聚类分割,将 所得聚类中心作为改进算法的初始聚类中心; 其次通过自适应非局部均值算法对图像进行平滑处理,避免图像过度分割;然后对引入核空 间邻域信息的目标函数进行最优化求解, 获取聚类中心和隶属度的迭代表达式;最后对像素进行分类时,利用邻域像素隶属度对像素 进行进一步滤波处理。实验结果表明:本文的 改进算法与传统FCM聚类算法、核空间FCM(KFCM)算法、基于邻域信息的FCM(FCM S)算法和基 于邻域信息KFCM(KFCM-S)算法相比,改进算法对强噪声干扰下的图像具有较好 的鲁棒性,并且能够有效分割图像的目标信 息和背景信息。从几种算法进行聚类分割结果所对应的峰值信噪比(PSNR)也可以看出,本文 改进算法的PSNR更高。     

基于协方差描述子的彩色图像分割算法

为克服模糊C均值聚类图像分割对噪声较为敏感的缺陷,提出了一种结合协方差描述子的模糊C均值聚类算法。采用协方差描述子的滤波能力以改善传统模糊C均值聚类算法对噪声敏感的缺陷;提取超像素的协方差矩阵作为特征,降低图像识别的特征冗余。并做了仿真实验,对提出的算法与三个图像分割算法进行比较,结果表明该图像分割算法具有较好的噪声鲁棒性和分割准确率。     

基于聚类算法的红外图像伪彩色增强

文中根据红外图像的特点,提出了一种基于K-均值聚类的红外图像伪彩色增强的新算法.该算法通过对红外图像灰度数据的统计学习,产生初始聚类中心,采用K-均值聚类算法对灰度进行聚类,并根据伪彩色编码的节点对聚类结果分段实现伪彩色的自适应分配.实验结果表明,该方法可增强红外图像的细节信息和层次感,具有更好的视觉效果.     

基于邻接矩阵的自适应图像分割算法研究

基于聚类的图像分割算法是其中常见的一种,传统聚类算法需人为确定初始聚类中心和类别数,针对如何确定最优聚类类别数的问题,基于邻接矩阵提出一种自适应图像分割算法,该算法克服了传统聚类算法人为确定初始聚类中心和聚类类别数而导致局部最优的缺陷。利用实验数据将算法和传统聚类算法比较,并应用于图像分割。实验结果显示,算法稳定性较好,能自适应的得到准确地聚类类别数,且鲁棒性较强,在应用于图像分割时的聚类结果相对与传统聚类算法更加准确。     

基于近邻搜索花授粉优化的直觉模糊聚类图像分割

为克服传统模糊聚类算法应用于图像分割时,易受噪声影响,对聚类中心初始值敏感,易陷入局部最优,模糊信息处理能力不足等缺陷,该文提出基于近邻搜索花授粉优化的直觉模糊聚类图像分割算法。首先设计一种新颖的图像空间信息提取策略,进而构造融合图像空间信息的直觉模糊聚类目标函数,提高对于噪声的鲁棒性,提升算法处理图像中模糊信息的能力。为了优化上述目标函数,提出一种基于近邻学习搜索机制的花授粉算法,实现对于聚类中心的寻优,解决对于聚类中心初始值敏感,易陷入局部最优的问题。实验结果表明所提算法能在多种噪声图像上取得令人满意的分割效果。     

动态聚类算法在网络入侵检测中的应用

为了进一步提高网络入侵检测技术的检测率,降低误报率和漏报率.针对普通聚类算法存在的聚类结果对随机选取初始聚类中心敏感、分类结果不稳定,从而造成的检测率低、漏报和误报率高的特点.提出一种基于动态聚类算法的网络入侵检测模型,实验结果表明通过在K-均值聚类算法的基础上增加动态迭代调整聚类中心,使聚类结果更稳定更准确.与K-均值聚类等算法相比提高了网络入侵检测的性能,从而表明该算法的可行性,有效性.     

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.