Linux操作系统的网络安全问题分析

为了提高Linux操作系统安全性,通过分析研究当前国内外安全操作系统技术,以访问控制为研究内容,在基于角色的访问控制这两方面,对Linux内核进行研究和改进,并验证了改进的RBAC模型相关定义、状态转换以及一致性规则：     

Solaris下基于角色访问控制模型的研究与应用

操作系统作为信息系统的基础,其安全性不容忽视.访问控制是维护和保证系统安全的重要方式,而基于角色访问控制(RBAC)是访问控制领域新兴的热点.以Sun公司的开源操作系统Solaris为例,分析了RBAC模型的结构和工作原理,同时,对Solaris下角色访问控制的具体实现进行了研究,提出了一种针对超级用户权限的控制方法,更好地实现了最小特权原则.     

RBAC模型在信息处理系统中的研究与应用

先将传统的访问控制方法与基于角色的访问控制方法进行比较，详细介绍了基于角色访问控制模型的各组成部分，然后论述了RBAC模型在具体系统中的应用与实现，最后提出了今后RBAC的研究方向。     

强制访问控制在基于角色的保护系统中的实现

研究了通过对基于角色的访问控制（RBAC）进行定制实现强制访问控制（MAC）机制的方法。介绍了RBAC模型和MAC模型的基本概念，讨论了它们之间的相似性，给出了在不考虑角色上下文和考虑角色上下文两种情形下满足强制访问控制要求的RBAC系统的构造方法。从这两个构造中可以看出，强制访问控制只是基于角色的访问控制的一种特例，用户可以通过对RBAC系统进行定制实现一个多级安全系统。     

数据备份系统中基于角色访问控制模型的研究

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。文中分析了RBAC的基本思想和模型，然后介绍了用户角色分配和角色许可分配的基本方法，最后提出了在数据备份系统中运用RBAC实现用户权限管理的应用模型。并实现了标准建模语言UML的交互图描述RBAC的授权流程，从而使系统开发人员能深刻理解RBAC模型和建立基于角色的系统。     

一种RBAC的新模型及其在异构数据库系统中的应用

对基于角色访问控制（rule-based accss control ,RBAC)研究中的热点之一模型的建立进行了较深入的研究，提出了一种针对异构数据库系统新的RBAC模型——H-RBAC（Heterogcncous RBAC,异构基于角色的访问控制），H-RBAC模型引入角色集成继承实现局部角色和全局角色的层次关系，通过会话分流实现动态的访问控制，该模型能够高效、灵活地实现异构数据库系统的联合访问控制。     

基于RBAC模型的同名角色研究与设计

安全模型既是可信信息系统的核心内容,也是可信计算研究的重要领域.基于对角色访问控制（RBAC： Role Based Access Control）和安全操作系统标准的深入研究,提出了同名角色的概念,扩展了RBAC中角色的控制范畴,便于灵活地权衡控制粒度与空间需求的对立关系,实施细粒度的访问控制;同时根据同名角色的思想,为自主存取控制（DAC：Discretionary Access Control）系统提供了同名控制域的能力.最后,在FreeBSD操作系统中设计实现了同名控制域,提高了访问控制的灵活性.     

数据库管理系统RBAC特性研究

介绍了基于角色的访问控制模型RBAC 2000的基本特征，并从核心RBAC、层次RBAC和约束RBAC等三个方面分析和比较了几个通用数据库管理系统中基于角色的访问控制特性。     

角色访问控制模型的研究及应用

针对大型企业信息系统在访问控制和安全管理方面的复杂性，传统的访问控制策略不适应大型企业信息系统在安全方面的要求。对角色的访问控制（RBAC）模型进行详细的分析，针对RBAC的不足提出改进的IRBAC模型，并将它应用到企业信息系统的设计中，建立企业的安全访问控制策略。采用IRBAC模型的访问控制策略简化了角色层次结构，方便了角色授权。     

基于RBAC模型多级角色的SQLite3安全访问控制

针对嵌入式数据库SQLite3没有完整的安全访问控制的问题,本文基于RBAC模型,结合SQLite3数据库内核源码,设计了多级角色,分析了其访问控制的实现方法与步骤,详细设计并实现了 SQLite3的安全访问控制。实验测试结果表明该方法在继承SQLite3原有优点的同时,提高了SQLite3的安全访问控制能力。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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