关于强化信息安全保障体系的思考

信息的安全防护随着信息技术的发展而不断完善,由早期的通信保密发展到计算机信息系统的安全,直至现在大家关注的动态的全过程的信息安全保障。信息安全是指保护信息和信息系统不被未经授权的访问、使用、泄露、中断、修改和破坏,为信息和信息系统提供保密性、完整性、可用性、可控性和不可否认性。信息安全保障是保证信息与信息系统的保密性、完整性、可用性、可控性和不可否认性的信息安全保护和防御的过程。它要求加强对信息和信息系统的保护,加强对信息安全事件和各种脆弱性的检测,提高应急反应能力和系统恢复能力。信息安全保障体系是…     

通信网的信息安全

本文首先介绍了通信网安全的基本含义，进而提出了信息安全的层次结构，用户信息安全和网络信息安全的主要内容以及实现信息安全的服务和机制。     

智能电网的信息安全技术探讨

智能电网的信息安全问题必须在智能电网部署的过程中充分考虑,防患于未然,文章主要对智能电网的信息安全技术在物理安全、网络安全、数据安全及备份恢复、业务应用安全和网络通讯等方面进行探讨和研究,以期对智能电网的信息安全提供必要的建议。     

《公共信息安全事件管理办法》有望年底出台

近日,北京市信息化工作办公室主任朱炎就全市发生大面积网络瘫痪事件透露,年底前有望出台《公共信息安全事件管理办法》,其中将对面向百姓的公共信息安全明确提出管理要求。朱炎透露,根据调查,此次网络瘫痪事件的原因是支撑ADSL系统的路由器出现故障,瘫痪网络是在两个小时之内逐步恢复的。朱炎认为,当前信息安全工作越来越重要,确保信息安全已成为首都安全的重要组成部分,但目前信息安全事件的告知机制仍不完善, 如此次网络瘫痪,如果企业建立告     

信息安全风险评估方法研究

信息安全风险评估是建立信息安全保障体系过程中重要的评价方法和决策机制,是信息安全研究的重要组成部分。文章阐述了国内外信息安全风险评估的发展状况,对信息安全风险评估方法进行了分类和总结,通过对典型评估方法的讨论,深入分析了各种分析方法在评估过程中的优劣侧重和综合应用性。最后,就中国信息安全的发展状况,提出了在信息安全评估工作中急需解决的若干问题。     

美国网络信息安全治理机制及其对我国之启示

随着信息技术的不断创新和发展,网络环境的范围及深度不断扩展,在便于人们生活和创新经济发展模式的同时,网络安全问题也越发严重,如何通过有效地治理机制措施加强网络信息安全,成为制约当下网络发展的主要因素之一.本文通过分析了美国网络信息安全治理机制的内容,联系当下的网络信息技术和我国的网络发展现状,提出了美国网络信息安全治理机制对我国的启示.     

网络视频监控系统信息安全机制解析

信息安全机制是网络视频监控系统安全体系中的核心部分,其安全性包括业务数据安全性和音视频媒体数据安全性,对此,业界有多种解决方案和算法标准,选择了监控业界两个代表性网络视频监控标准的信息安全机制进行解读,分析了主流解决方案和算法,最后提出了通用的视频监控的信息安全机制建议.     

大数据面临的信息安全问题及合理应对方式分析

信息安全是保证社会稳定的一个关键点,以大数据时代为前提,从建立信息安全机制、信息技术创新、信息安全观念以及安全防范技术四方面,对当下面临的信息安全问题以及应对方式进行了分析,为提升互联网的平稳性、实现快速发展发挥了重要作用。     

一种蓝牙安全机制的密钥算法改进

文中重点分析了蓝牙的信息安全机制,对其各部分的密钥算法及实现步骤进行了详细的研究与分析,针对蓝牙信息安全体制中存在的不足提出了由AES算法构建的一种新的安全机制,文中通过对新的安全机制的分析与测试,不但实现了对蓝牙安全机制的密钥算法的改进而且不影响蓝牙的通信效率,结果表明新的安全机制能够满足安全性要求较高的蓝牙应用.     

计算机网络入侵检测应用免疫机制的效果探讨

近年来,伴随着计算机网络的迅速扩大,信息安全面临着不断增多的非法入侵等巨大考验.免疫机制的出现,改变了传统的防火墙和权限管理对网络信息安全的保护不足的问题,是一种全新的网络安全保障措施.本文针对免疫机制在计算机网络入侵检测中的应用展开了具体的分析,以供大家交流探讨.     

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.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

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.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

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.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

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.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.