基于角色的访问控制框架的研究与实现

介绍一种基于角色的访问控制框架，详细阐述了该框架的实现原理和工作机制.基于角色的访问控制（RBAC）是一种关于授权管理的概念模型，与传统的授权策略相比，它更加灵活、安全且易维护.基于角色的访问控制框架在原理上对RBAC基本模型进行了概念扩展，根据大规模数据资源授权管理的需要，提出了更加细化的资源概念和明确的权限判定机制。     

RBAC模型在校园信息门户访问控制中的应用

校园信息门户是对校内资源的整合，是目前校园网应用建设的一个新的发展方向。访问控制则是实现对于不同的用户通过门户进入以后能够提供不同的信息服务。本文将RBAC模型应用到校园信息门户的访问控制中，并将用户组引入RBAC模型中，对RBAC模型进行扩展。在此基础上，与LDAP用户信息结合在一起，提出了一种基于用户、用户组、应用和角色相结合的权限控制方法，并应用到校园信息门户的访问控制中。     

基于RBAC的多级模块访问控制的实现

在Web应用中，多级模块需要多级访问控制进行管理，基于角色的访问控制（RBAC）是解决这类问题的好方法。提出了一种ASP．NET环境下，运用RBAC原理，对多级模块进行权限控制的设计和实现过程。经过实际使用证明．该法能够对用户权限进行精确控制，提高了应用的安全性。     

基于数字证书认证的访问控制研究

分析了当前网络应用系统中访问控制方面的不足,深入研究和分析了RBAC访问控制机制,提出了结合数字证书用户认证技术和RBAC的访问控制技术,实现网络用户认证、访问控制和授权管理相统一的安全网关系统,解决了信息系统访问控制管理能力不足、认证能力差的缺点。     

WSRBAC在管理信息系统中的应用

基于角色的访问控制(RBAC)模型是一种有效但比较被动的访问控制模型,不能对主体所拥有的权限进行动态管理,面向工作流和服务的RBAC(WSRBAC)模型基于RBAC但更为有效。论文介绍了WSRBAC相关的基本概念,阐述了WSRBAC的访问控制规则,给出了一种形式化的描述,结合某数控设备开发实例,实现了WSRBAC在企业管理信息系统中的设计和应用。     

基于AOP的细粒度RBAC模型研究

提出一种新的基于AOP技术的RBAC访问控制模型,是对传统RBAC访问控制模型的改进,突破了传统RBAC模型中不具备对细分数据的访问控制的限制。同时,本文根据面向对象技术对不同种类的细粒度进行了有效抽象,采用现有Java Struts2和AOP技术进行了软件架构的设计,这种模型是一种通用的细粒度访问控制模型。本文所得出的细粒度RBAC模型具有较强的通用性,并在实际系统中得到了验证,取得了良好的效果。     

基于角色的访问控制模型在LDAP服务中的研究与设计

在分布式系统中，不同的计算机系统之间经常要进行资源的互相访问，由此而带来的安全性问题与通常环境下的安全问题有比较大的不同。文章首先分析用角色访问控制方法来实现分布式资源互访特点，然后讨论了如何在LDAP(Lightweight Directory Access Pmtocol)服务中实现基于角色的访问控制(RBAC)型，从而达到保证分布式系统中的资源共享。     

基于角色访问控制机制在Web信息系统中的应用

基于角色访问控制(RBAC)是一种方便、安全、高效的访问控制机制和重要的信息安全技术,他在满足企业信息系统安全需求方面显示了极大的优势。对RBAC模型——NRBAC模型进行了深入的研究,针对Web信息系统的结构特征及其对安全访问控制的要求,提出NRBAC模型的实现方案,从而利用基于角色访问控制技术实现系统的权限管理功能。     

网格环境下授权策略的研究

针对网格环境下授权的特性,分析了现有网格授权机制和访问控制模型的缺陷,提出了适用网格环境的TSRBAC授权模型.该模型以虚拟组织为基础,改进了RBAC策略,实现了权限的分布式管理和动态授权.通过将角色分离,满足了资源动态性和策略自主性的要求,适应了网格环境的特点.给出了该模型中概念的定义和形式化描述,并用该模型改进了CAS系统.     

基于属性证书和角色的PMI

PMI的出现,在访问控制方法上提供了新的思路。本文先简要介绍了NIST的RBAC建议标准的4种RBAC基本模型,以及X.509 v4(2000)中定义的属性证书和特权管理基础设施PMI的基本模型和访问控制模型,然后结合RBAC和属性证书提出一种基于属性证书和角色的PMI应用模型, 并分析了模型的实现过程。     

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.     

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.     

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.