垃圾邮件过滤技术

电子邮件已经成为人们日常生活中通信、交流的重要手段之一,但垃圾邮件问题也日益严峻,网民平均每天收到的垃圾邮件数量已超过了正常邮件.因此目前反垃圾邮件技术的研究成为了一个热门的话题.文中介绍了基于安全认证、规则匹配和统计学习三类邮件过滤技术及应用情况,分析了过滤技术面临的挑战并指出垃圾邮件过滤的发展趋势.     

垃圾邮件过滤技术发展现状及展望

电子邮件随着Internet的发展给人们带来了方便,但随之而来的垃圾邮件也给人们带来了不少的烦恼。针对垃圾邮件技术的发展与现状,本文对目前的垃圾邮件过滤技术进行了分析,并指出垃圾邮件过滤的发展趋势。     

网络安全和垃圾邮件技术防范体系

电子邮件日益成为人们不可或缺的重要通信手段,垃圾邮件的泛滥极大地影响了网络信息安全和人们的正常工作与生活。本文分析了垃圾邮件的产生原因、分类及其危害．进而从发送垃圾邮件的行为和垃圾邮件内容两个方面讨论了垃圾邮件的防范技术与多层体系。     

垃圾邮件问题及其处理方法

随着互联网的发展,电子邮件作为一种通信方式逐渐普及,而垃圾邮件问题严重干扰了电子邮件的有效使用并产生了极大的社会影响.本文从技术角度和社会角度分析了垃圾邮件问题的成因,对现有的垃圾邮件处理方法进行了系统的分析,并从使用范围、维护手段、效率等多方面对处理方法进行了比较.     

启明星辰：致力于中国防垃圾邮件

互联网高速发展的今天，人们在充分享受电子邮件带来的便捷、高效和廉价的优点，同时也饱尝了污染网络环境，影响网络正常通信的垃圾邮件带来的烦恼。近日，启明星辰信息技术有限公司推出了“天澄防垃圾邮件系统”，不但融合了目前市场上所有的主流垃圾邮件检测技术，更是加入了RBL技术．智能检测技术。其中，最引人注目的亮点就是启明星辰自主研发的专利技术——“可追查性检查”技术，通过这项专利技术，能够更加有效地抑制垃圾邮件的传播，极大地提高防垃圾邮件系统的工作效率。     

垃圾邮件的长尾现象分析及应用

随着互联网的发展,网络应用越来越广泛,电子邮件已经成为人们日常生活中通信和交流的重要手段之一,但垃圾邮件和病毒邮件问题也日益严峻,每天收到的垃圾邮件和病毒邮件数量已经超过了正常邮件,严重影响了用户对电子邮件的正常使用。文中从长尾理论的概念入手,简单介绍了长尾理论的应用,通过对过滤的垃圾邮件和病毒邮件进行统计和分析,揭示了垃圾邮件和病毒邮件也具有长尾现象,从中得出了防止和控制垃圾邮件和病毒邮件的新方法和新途径。     

基于贝叶斯方法的一种垃圾邮件过滤的实现

随着Internet的迅速发展，电子邮件的应用变得十分广泛，但是许多无用、有害的信息也随之而来。文章通过对垃圾邮件的分析与处理，运用贝叶斯方法建立一个自适应性又能够个性化的自动邮件过滤系统。该系统可以较为容易地识别出垃圾邮件，降低误判率。     

最小风险的Naive Bayes技术在反垃圾邮件系统中的应用

文章提出了一套更好地过滤中文垃圾邮件的方案，这套方案将利用垃圾邮件规律的规则过滤和最小风险的Naive Bayes内容过滤算法结合了起来，并根据垃圾邮件的特性做了必要的改进。并且这套方案也在Linux／Solaris系统平台下基本上完成了大部分功能的软件编程。实际电子邮件服务器上对本方案进行了测试．结果显示这套方案取得了很好的过滤效果。最小风险的Naive Bayes技术是目前最重要的反垃圾邮件技术之一。     

应对垃圾邮件的“要”与“不要”

2009年8月,垃圾邮件数量平均占到电子邮件总数的87％。与健康有关的垃圾邮件平均占6．73％,而与互联网相关的垃圾邮件超过了29％。     

垃圾邮件及其过滤技术概述

电子邮件已成为现代生活通信、交流的重要手段,也是INTERNET服务的主要内容之一,然而垃圾邮件问题日益严重,给用户带来重大损失,如何防范垃圾邮件已成为研究热点。本文主要讨论邮件传递过程的垃圾邮件过滤问题,简单介绍SMTP配置、IP过滤规则设置、用户过滤规则设置以及邮件过滤规则设置等邮件过滤技术。     

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.