基于主题的用户兴趣域算法

针对用户兴趣偏好多变问题,提出一种兴趣特征权重随时间而变化的迭代计算方法。构造了用户兴趣特征与主题类间的二部图关系,并在此基础上提出了一种基于主题的用户兴趣聚类算法(TBC),改变了聚类对象"非此即彼"的硬划分方式。该算法所形成的基于主题的用户兴趣域结构,不仅充分表达了用户的多域兴趣特征和域间主题的联系,还能适应用户兴趣变化。实验表明,TBC算法比传统的K-Means算法以及属于软划分方式的FCM聚类具有更好的用户兴趣划分效果,并且在个性化推荐服务中表现出更高的推荐质量和效率。     

基于K-Means聚类的在线学习用户个性化分类

如何利用人工智能提供个性化学习环境及服务已成为当前教育研究者关注的焦点.随着各种在线学习平台的层出不穷,如何利用信息技术提供个性化学习环境及服务已成为当前研究热点.本文基于在线学习平台"超星泛雅"中《网页设计与制作》在线课程案例,重点介绍了数据挖掘算法中K-Means聚类算法的应用.针对传统IFL模型的不足,结合在线学...     

基于谱聚类的用户关联关系挖掘

为了从用户地理空间分布数据中挖掘用户间关联关系,提出了一种基于谱聚类的关联关系挖掘算法.首先定义了关联度,用以衡量用户之间空间分布的相似性,基于关联度构造相似矩阵,再利用谱聚类方法对用户进行聚类分析,聚类结果表征了用户的关联关系.采用Silhouette指标和聚类准确率来衡量用户关系挖掘质量,同时与传统的K-Means方法进行了比较,通过真实数据集实验,结果表明该算法在实验数据集上能达到90％以上的聚类准确率,证明方法有效、可行.     

个性化服务中用户兴趣聚类算法研究

讨论了个性化服务中用户兴趣建模对聚类算法的要求,指出经典聚类算法应用于用户兴趣聚类时的不足。在基于图论的K近邻聚类算法的基础上进行改进,提出一种基于相似度的聚类算法。实验证明,与K近邻算法相比,该算法能够显著提高聚类质量,有效区分孤立点,适用于用户兴趣聚类。     

基于K-Means算法的雷达信号预分选方法

K-Means算法在雷达信号预分选中有着广泛的应用,传统K-Means算法对聚类个数以及聚类中心的初始设定依赖性很大,并且对噪声和孤立点很敏感,针对这些不足,文中提出了一种将距离法与改进的K-Means算法相结合的雷达信号预分选方法。仿真实验表明提出的方法可以有效的降低了噪声和孤立点对K-Means聚类算法的影响。     

K-Means聚类算法研究及图形演示的实现

K-Means聚类算法用于将数据分成类,同一个类中的数据之间具有很高的相似度,而不同类中的数据高度相异.K-Means聚类算法已在网络入侵检测、计算机图像处理等领域有着广泛的应用.研究了K-Means聚类算法的原理,并通过VC+ +6.0实现了K-Means聚类算法聚类过程的图形演示.     

一种对孤立点不敏感的新的K-Means聚类算法

针对传统K-Means聚类算法的不足,提出一种新的对孤立点不敏感的K-Means聚类算法。首先,采用孤立点移除算法消除数据集中存在的孤立点;然后,对不包含孤立点的数据集进行传统K-Means聚类,再引入轮廓系数并选择轮廓系数最大值对应的簇类数作为数据集中簇的最优选择数目K;最后,通过自定义的聚类有效性评价函数评估聚类效果。实验结果表明,相对于传统K-Means聚类算法,对孤立点不敏感的新的K-Means聚类算法能够消除孤立点对数据集整体的影响,并优化了聚类中心的选择。     

基于加权矩阵聚类的Web日志挖掘算法

Web服务器日志中记录了用户的浏览模式,为了从中提取出具有相似访问模式的用户群,对其提供个性化服务,提出一种针对Web日志的分析方法。通过构建UserID-URL关联矩阵,引入加权关联矩阵,提出一种基于加权矩阵的聚类算法——多标记传播算法。实验表明,该算法在Web日志挖掘中进行用户聚类和页面聚类是高效可靠的。     

基于K-Means变异算子的混合PSO算法聚类研究

提出了基于K-Means算子的混合粒子群优化算法聚类,将K-Means算法的局部搜索能力与粒子群优化算法的全局寻优搜索能力相结合,根据群体适应度变化的情况自适应调整权重,并对种群中性能较差的粒子进行交叉选择,能充分挖掘群体本身信息,又能不断引入附加信息.数据集仿真实验表明,该算法有效的克服了传统粒子群优化算法过慢收敛和K-Means算法陷入局部收敛的问题,从而得到更好的聚类效果.     

基于Bisecting K-Means聚类的公路交通流状态划分方法

<正>为了缓解交通拥堵，提高出行效率，交通部门需要对交通流状态进行分类识别以确定交通状态。基于K-Means聚类算法进行公路运行状态划分易受到初始聚类中心点选择的影响，因此本文在K-Means算法的基础上进行改进，将BisectingK-Means应用于公路运行状态的划分，各交通状态中心点的距离较远，避免了初始聚类中心会聚到一个交通状态，一定程度上克服了K-Means算法陷入局部最优值。     

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.     

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.     

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.     

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