基于角色访问控制的改进

对于服务系统的访问、控制直接关系到系统的安全和服务系统的基本功能.常见企业管理信息系统在基于角色的访问控制(RBAC)方面存在着一些不足.因此结合XML在安全管理上的处理模式,提出改进了的RBAC方案.该方案实现了权限转移及页面元素的访问控制,使得权限分配更加灵活、安全.     

基于树型角色的访问控制策略及其实现

对于工作职能耦合度高、业务呈交叉状的企业,传统的基于用户或角色的访问控制(RBAC)策略已难以实现信息系统的权限管理．文中结合RBAC的基本思想,提出了一种分层的树型角色访问控制(TRBAC)模型,并在应用程序层实现了基于角色的权限管理方案,实践表明,TRBAC简化了用户、角色和许可三者之间的配置规则,方便了系统的授权管理．     

支持授权委托的细粒度角色访问控制模型

针对传统RBAC模型在大型综合集成系统中的权限管理以及访问控制的不足,从授权委托和访问控制的细粒度方面对RBAC模型进行扩充,通过将客体资源按主体的意图以尽量小的粒度分解和设置角色属性以实现细粒度的访问控制,附加时间约束来增强模型对角色、权限、委托等的约束能力,并且引入授权委托机制以及角色组的概念,解决了综合系统授权管理的复杂性和集中性问题.     

web信息系统中访问控制策略的研究与实现

访问控制技术在web信息系统中得到大量应用,相较于传统的自主访问控制模型和强制访问控制模型,基于角色的访问控制(RBAC)具有更强的灵活性和经济性,本文在此基础上引入组织概念,并采用动态权限,提高了效率。     

RBAC模型在数字化校园中的应用研究

基于角色的访问权限控制(RBAC)可以控制不同级别的用户对系统应用程序和数据的访问,是提高管理信息系统安全性的一种有效手段.以RBAC的基本模型为依据,对数字化校园的安全机制进行了研究,并将RBAC模型成功应用到系统的研发中.     

基于双角色权限控制的B/S结构管理信息系统安全机制

B/S结构管理信息系统能够有效地克服C/S结构"信息封闭、效率低下和难以协同"的缺点,但因其开放性导致存在严重安全隐患.如何在业务流程有序控制限制下,实现业务数据的安全访问控制和灵活授权管理,成为B/S结构管理信息系统安全机制的关键问题.主流基于角色的访问控制RBAC模型通过"用户-角色-权限"的授权机制实现安全访问控制和灵活授权管理,但RBAC没有提供业务流程控制机制,因而难以应用到具有严格的业务流程次序操作的实体信息系统中.基于对RBAC模型的改进,提出基于双角色的权限访问控制DRBAC模型,是在实现安全访问控制和灵活授权管理的同时,提供了一种业务流程控制机制,能够较好适应具有严格操作次序要求的B/S结构实体信息系统.     

基于角色访问控制的权限管理系统改进与应用

对基于角色的访问控制模型进行了研究,对传统访问控制模型、基于角色的访问控制（RBAC）模型、角色管理模型ARBAC97进行了描述和分析。对RBAC模型进行范围扩展,通过引入角色范围的概念,以（用户,角色,范围）三元组来标识系统用户的权限,解决RBAC模型无法对资源实例进行权限控制的问题,也就是解决了系统用户拥有相同的角色,操作的数据范围可以不同。结合实际应用系统的需求,实现了权限管理系统。     

OA系统中RBAC扩展模型的研究与实现

针对传统基于角色的访问控制(Role-based Access Contion,RBAC)模型在授权管理上的缺陷,结合某人才服务中心OA系统对权限控制的需求,提出了一种扩展的RBAC模型.首先,用户组的引入有效避免了在大型应用系统中权限和角色分配的较为繁杂的工作.其次,基于三权分立的原则,将管理员分为系统管理员、安全管理员和审计管理员,避免了超级管理员权限过大所带来的问题.同时,采用独立的安全审计,对用户及管理员的操作进行记录,防止非法操作和滥用权力.在OA系统中应用该扩展RBAC模型,进一步增强了系统的安全性与可靠性.     

角色权限分配模型研究

在RBAC模型中,由管理员进行角色-权限分配可导致系统访问控制策略的实施存在一定的安全漏洞.在对RBAC进行研究的基础上,建立了角色-权限分配模型.该模型运用角色的属性,采用角色分解方法产生角色-权限的对应关系,从而保障了系统访问控制策略的正确实施,同时也减轻了管理员的负担.     

RBAC模型在权限控制中的研究与实现

学术界对于权限管理已经做了大量的研究工作并提出了许多种模型,其中基于角色的访问控制(RBAC)模型是近来广泛流行的模型之一,现在已经比较成熟.本文介绍了RBAC模型,分析了当前比较流行的Acegi框架.依据RBAC模型理论,采用AOP思想,利用基于Spring的Ace-gi安全系统,设计了一套权限控制方案,从而简化了系统中的认证和授权管理.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with