基于协议分析的入侵检测系统的设计

对基于协议分析的入侵检测系统的有关技术进行了分析和研究,将网络入侵检测系统的有关协议和传统的监测系统相结合,通过协议的规范性来减少网络监测系统的工作难度,利用模式规范来确保网络的安全性。     

基于IPv6的动态网络入侵检测系统的研究与设计

随着互联网应用的普及,网络攻击行为愈来愈严重.依据IPv6协议的扩展头、包头结构、地址结构和安全机制,设计了IPv6环境下的协议解码和协议分析的过程.提出了一种新的基于协议分析的网络入侵检测系统框架.通过对协议解码和分析,给出了IPv6环境下基于协议分析的网络入侵检测系统的设计方案.     

基于Octeon多核网络处理器的IPv6联动IPS研究与设计

对基于Octeon多核网络处理器的新一代IPv6高速网络联动入侵防御系统进行研究,设计了新型联动入侵防御原型.系统基于Octeon多核的高速处理,并结合了IPv6网络中入侵的新特点.在基于入侵检测规则库规则匹配技术的基础上,运用新型的协议分析技术和基于流的检测技术,在Octeon多核间分配控制层与数据层的不同执行,采用命名块机制进行多核间通信,通过数据层核向控制层核的反馈,实现了流处理及协议分析模块与控制模块的高速联动.系统实现了Gbps级的高速入侵检测与联动防御处理.     

基于协议分析的网络入侵检测与取证系统

在检测到非法入侵或恶意行为时利用入侵检测系统(IDS)收集电子证据是IDS新的应用方 向,也是IDS领域的研究热点之一,本文依照IDS的体系结构,结合协议分析和模式匹配技术,提出了 一种基于协议分析的网络入侵取证系统结构模型,用于在线入侵检测、离线取证分析。     

高速网络环境中入侵检测技术探讨

由于TCP／IP协议的开放性，入侵检测网络安全技术备受业界人士的关注。为了研究在未来高速IPv6互联网中的入侵检测技术，通过分析传统入侵检测系统的局限性，论证了在IPv6环境下采用基于协议分析技术的入侵检测系统（Protocol Analvze Based Intrusion Detection System，PAIDS）的必要性和可行性，并讨论了其基本思想及需要进一步研究的技术内容。研究结果表明：该技术与传统的入侵检测系统（Intrusion Detection System，IDS）相比具有准确率高、系统占用资源低、速率快等优势。     

基于网络事件和深度协议分析的入侵检测研究

针对制约NIDS(基于网络的入侵检测系统)的问题,提出了基于网络事件和深度协议分析的入侵检测模型MIDM,实现了对入侵的分析与综合。扩展了ABNF范式形式化定义网络事件,基于所提出模型重新实现了入侵检测系统。实验证明与当前主流NIDS相比,新模型有效降低了误检率和特征库冗余;具有随网络流量和特征库快速增长,而CPU占用率维持低水平增长的特性,能更好地适应高速网络环境;同时还具有一定的特征泛化和检测未知入侵的能力。     

基于IPv6的免疫入侵检测自我集生成方法

基于人工免疫的入侵检测已成为网络安全研究领域的一个重要方向。基于人工免疫的入侵检测的免疫耐受过程和检测过程都需要进行匹配操作,匹配的前提是必须对“自我”与“非我”进行有效的特征编码,编码方案的好坏关系到检测系统的效率及准确率。通过介绍协议解析技术,对IPv6协议进行分析,提出一种IPv6数据包编码方案,能够较有效地生成自我集。     

基于IPv6的入侵检测系统的研究与实现

在Snort软件包的基础上,对下一代英特网入侵检测系统的实现进行了研究,提出了基于IPv6的入侵检测系统的解决方案,阐述了协议解析模块、分段包重组模块、规则检测模块和报警输出模块的设计实现方案.     

NIDS中协议分析和模式匹配的研究

对入侵检测系统中的关键部分一检测引擎的数据分析中的模式匹配技术和协议分析技术进行了介绍。讨论了模式匹配中最常用的两种算法一KMP算法和BM算法，重点分析了模式匹配技术运用在网络级入侵检测系统中的不足，并指出结合使用协议分析和模式匹配进行数据分析的优越性。     

联想网御入侵检测系统通过评测

近日,赛迪评测对联想新推出的网御入侵检测系统进行了全面的产品评测。联想网御入侵检测系统是基于网络的入侵检测及响应系统(NIDS)。其采用分布式入侵检测系统构架,综合使用模式匹配、异常分析、状态协议分析、行为分析、内容恢复、网络审计等入侵分析技术,全面监视网络的通信状态,实时捕获入侵、误用、滥用等违反网络安全策略的行为,并针对可疑的入侵行为,依据策略做出主动反应、及时告警及事件日志记录,最大限度保障网络系统安全。经赛迪评测全面评估,联想网御入侵检测系统属于一款优秀的入侵检测系统。(吕莉,摘自《通信产业报》)联想…     

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.