入侵检测技术在网络安全中的应用与研究

随着计算机网络技术的发展,网络安全成为一个突出的问题.文中介绍了网络安全的概念和现状,分析网络安全的防范技术,着重探讨了入侵检测技术.入侵检测是网络安全和信息系统安全中的重要技术手段.本文对该技术的概念、分类和主要技术方法进行了分析,给出了入侵检测系统的概念及工作流程.对目前比较热门的基于数据挖掘的入侵检测技术进行了深入的研究,并给出了基于相似度和孤立点挖掘算法的描述.     

Linux下的网络入侵检测系统研究与实现

随着计算机信息技术与网络技术的迅猛发展，信息与网络的安全形势也日趋严峻和复杂化。各种计算机安全事件的不断发生，已使保障信息与网络安全成为世界各国计算机安全人员的共同目标。主要介绍了网络入侵检测系统（NIDS）的设计原理和在Linux操作系统（主要是在RedHat）下，对网络入侵检测系统的设计进行了探讨。     

基于入侵检测技术的网络运行安全分析

最近几年,在我国的各个行业、领域中已经实现了计算机网络管理模式,但是随之而来的网络运行安全问题逐渐成为人民关注的重点。入侵检测技术是目前保护计算机网络安全的新型网络安全技术之一,不仅能够对入侵行为进行信息收集、分析检测、及时响应,还可以弥补防火墙的缺陷,确保计算机网络的安全运行。本文将重点探讨入侵检测技术的概念以及在计算机网络运行中的安全防护策略。     

计算机网络安全中入侵检测系统的研究与设计

随着计算机病毒、黑客入侵等网络信息安全事件发生频率的逐渐增高,人们越来越意识到网络安全的重要性.网络安全已成为当前计算机网络领域所面临的一个最为主要的问题.入侵检测系统作为时下IT领域内网络信息安全的一门新型热门技术,在保障网络安全方面占有举足轻重的地位.本文主要介绍了入侵检测有关内容,入侵检测的主要方法,以及基于计算机网络安全入侵检测系统的设计.     

多维校园网安全模型研究

介绍了生物免疫原理,简要分析了生物免疫系统为构建健壮的计算机安全系统提供的线索,并将其思想融合在多维校园网安全模型的研究设计中。在网络安全层面分析了安全产品互操作和联动管理的需求,介绍了开放式管理框架OPSEC的相关技术,研究了网络安全监控系统与其他安全产品（如防火墙、入侵检测系统）之间联动管理的实现方式及对整体网络安全性能的影响。     

基于计算机免疫技术的入侵检测系统研究

计算机免疫技术是直接受到生物免疫机制的启发而提出的。作为一项新的技术它已经引起了人们对它的广泛注意。入侵检测是监测计算机网络和系统以发现违反安全策略事件的过程。它作为一种积极主动的安全防护技术,在网络系统受到危害之前拦截和响应入侵。所以入侵检测在计算机安全方面起着非常重要的作用,同时对它的技术要求也就非常高。本文主要介绍了计算机免疫技术以及将其应用到入侵检测方面的想法。     

基于计算机免疫技术的入侵检测系统研究

计算机免疫技术是直接受到生物免疫机制的启发而提出的。作为一项新的技术它已经引起了人们对它的广泛注意。入侵检测是监测计算机网络和系统以发现违反安全策略事件的过程。它作为一种积极主动的安全防护技术，在网络系统受到危害之前拦截和响应入侵。所以入侵检测在计算机安全方面起着非常重要的作用，同时对它的技术要求也就非常高。本主要介绍了计算机免疫技术以及将其应用到入侵检测方面的想法。     

网络入侵防御系统研究

入侵行为给基于网络的计算机信息系统的安全带来了巨大威胁,入侵防御系统(IPS. Intrusion Prevention System)是网络安全领域为弥补防火墙及入侵检测系统(IDS)的不足而新发展 起来的一种计算机信息安全技术。IPS综合了防火墙防御功能和入侵检测系统的网络数据包检测功 能,已经成为网络安全领域的究的热点。     

入侵检测系统IDS在网络安全中的具体应用

当今信息化时代,计算机网络技术在经济、社会、政治、军事、教育等诸多领域得到普遍应用,与此同时,网络安全问题也成为众多专家、学者关注的热点问题。入侵检测系统IDS在网络安全中的具体应用尤为重要,本文以入侵检测系统IDS在网络安全中的具体应用为切入点,首先分析了入侵检测以及入侵检测系统内涵,接着介绍入侵检测系统主要构成,对三种常见的入侵检测方法做了细致的阐述。     

入侵检测中数据挖掘技术的运用

网络已经成为人们获取信息的重要途径。在日常生活与工作之中,人们对于网络的依赖性越来越强。与此同时,黑客技术也在快速发展,网络安全威胁日益严重,因此必须要为网络与计算机安全提供更多的保护。作为网络安全保护中的一种重要手段,入侵检测能够发挥出相当大的作用。然而传统的入侵检测方法已经难以满足当前的网络安全需要,需要对入侵检测系统进行改进。文中则主要探讨了入侵检测中数据挖掘技术所能够发挥的作用与运用方式。     

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.