基于映射机制的细粒度RBAC委托授权模型

针对现有RBAC(Role-Based Access Control)委托授权模型存在的不足:其一,没有有效地实现细致委托粒度;其二,权限传播没有得到很好的控制,给出一种基于映射机制的细粒度角色委托模型RDBMPM(Fine-Grained Role Delegation Model Based Permission Mapping Mechanism),该模型基于向量化与度量化算子的复合运算,提出了度量角色的概念,并以其为授权粒度对委托约束机制进行讨论,增强了权限传播的可控性.最后,通过三个典型的支持细粒度委托的模型在映射机制下的具体实现,验证了RDBMPM模型的研究意义.     

基于PMI的校园网格访问控制研究与应用

针对目前高校信息共享和协作中所面临的信息安全问题,提出一种基于PMI的访问控制模型。模型基于委托方式支持分布式授权;并通过委托约束和临时委托角色,支持角色委托和部分授权,遵循"最小特权"原则,并避免权限冲突和越权。     

基于角色权限管理扩展模型的设计与实现

基于角色权限管理模型对于大规模授权具有优势,但缺少了对一个用户授权的灵活。提出了合理可行的改进模型。采用J2EE经典的开源工具实现了这个扩展型基于角色权限管理模型。在保留角色授权的同时,增加了给某个用户单独授权的机制。扩展模型很好的丰富了基于角色权限管理模型的授权方式。     

网格计算环境的一种基于信任度的授权委托机制

针对网格计算环境下跨域授权过程的委托服务需求,在现有的RBDM和RT模型基础上,结合主观信任机制对委托过程进行信任协商,实现角色和权限的授权委托过程,并给出了细粒度的授权委托策略,最后对委托过程中的主观信任机制进行仿真,证实了使用信任度实现对委托过程控制的有效性.     

云平台下CRM系统访问控制研究与设计

文章对比分析了主流的访问控制模型,以基于角色的访问控制模型为基础,设计了适合云平台下CRM系统的访问控制机制,该机制增加了用户组、部门、资源、操作等实体。在优先通过角色授权的基础上,允许对用户直接授权,在权限设计中增加了用户权限直接授权,用户角色权限的动态授权等。本文还介绍了云平台下CRM系统的访问流程,并实现了云平台下CRM系统的访问控制。     

办公自动化系统中基于RBAC的授权模型

在基于角色的访问控制(RBAC)中,只给角色分配权限,用户必须成为角色中的一员才能取得相应的访问权限。基于角色授权的基本思想是:系统中某个成员将自己所拥有的权限授予另外一个成员,使之代表自己完成一定的工作。由于授权特征的多样性,授权模型有多种不同的状态。首先归纳出与授权有关的几种基本特征,然后根据办公自动化系统的具体业务情况将授权特征的组合进行精简,找出一组合适的状态,从而建立起办公自动化系统的授权模型。     

电子政务中基于角色的交叉集散授权策略

为了能够准确、有效、安全地为参与电子政务的部门或人授权,针对权限交叉带来的管理混乱现象,论文构建了基于角色的扩展授权模型(ExtendedRole-BasedAuthorizationModel,简称ERBAM),使用向上查询授权人的集中与分散授权方法,提出了基于角色的交叉集散授权策略,有效解决了电子政务中权限有交叉的授权管理问题。该方法已经成功应用于某电子政务系统。     

多约束的基于角色的访问控制扩展模型

基于角色的访问控制模型是访问控制中一个被广为接受的模型,但作为静态的被动控制模型,权限没有时间约束,在动态授权约束上存在局限性。引入任务的概念并阐述相关约束,提出多约束的基于角色的访问控制扩展模型,模型中通过任务或任务实例将角色和权限联系在一起,使得权限管理更为灵活,减轻了管理员的负担,满足动态职责分离原则、最小权限原则和限制权限继承原则等。     

基于LAMP架构的Web权限控制组件的设计与实现

设计并实现了一种LAMP(Linux、Apache、MySQL、PHP)架构下的权限控制组件,该组件采用基于角色的访问控制模型(RBAC),实现Web应用的权限认证控制。权限控制组件主要包含权限管理模块、角色管理模块和权限认证模块3个主要部分,其中权限认证模块是整个组件的核心,其将权限细分为操作权限和资源权限的方式不仅很好的避免了权限表急剧膨胀的问题,而且使得授权流程更加简单和高效。     

开放网络环境中基于动态信任管理的通用访问控制模型

综合基于角色的访问控制和信任管理的各自优势,通过引入信任级别概念,文章提出了一个适用于开放式环境的动态信任通用访问控制模型--DTMGAC(Generic Access Control Model Based on Dynamic Trust Management).模型依据用户身份信任和信任的动态度量,由信任级对角色分配关系实施约束,通过信任级动态调整角色权限分配关系,实现对角色可信授权委托控制.该模型具有良好的自治特性,不仅能细化访问控制粒度,增强系统实用性,而且还能有效降低威胁风险.     

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.     

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.     

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.     

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.     

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.     

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.