IPsec中安全策略库管理的编程实现

IPsec是虚拟专用网的一个标准，它规定了二个策略组件：安全关联数据库（SAD）和安全策略数据库（SPD）。IPsec系统中，安全策略主要通过SPD得到反应，而SAD是SPD的具体实现。本文首先给出安全策略的数据结构定义，然后给出安全策略的具体表示形式，最后编制程序，分别以命令的输入和套接口通信实现安全策略库管理。IPsec系统所使用的策略库一般保存在一个策略服务器中。该服务器上存放域中所有节点的维护策略库。各节点可将策略库拷贝到本地，也可使用轻型目录服务动态获取。IPsec中安全策略库管理的编程实现$武汉市海军工程大学…     

Oracle数据库安全及安全策略研究

Oracle数据库是市场占有率第一的数据库,其安全问题关系到大部分公司业务数据的安全性、私密性、完整性。从权限管理、用户管理、审计控制、密码安全四方面研究Oracle数据库的安全问题,并针对安全问题进行安全策略优化。经过该安全策略加固方法的实施,可以解决大部分Oracle数据库安全问题,达到保障数据安全的目的。     

高速边缘路由器安全数据库的研究与实现

随着计算机网络技术的发展，对网络核心设备的安全研究成为发展的热点。高速边缘路由器是骨干网和互联网/内部网之间的高速接入设备，在网络安全的研究中具有重要的意义。高速边缘路由器中的安全数据库管理包含了对安全策略的管理和对安全关联的管理，它的合理性和高效性是制约高速边缘路由器系统性能的重要因素。目前，安全数据库系统普遍采用集中式体系结构完成对安全策略和安全关联数据的管理，在系统的并行性、灵活性和访问效率方面都存在着较大的缺陷；分布式管理则由于各分布子系统间的一致性维护问题在高速边缘路由器中被充分放大而无法满足高速边缘路由器的设计要求。本文基于ForCES协议框架提出了一种高速边缘路由器的体系结构CeDita，并详细分析了基于该体系结构的安全数据库混合式管理模型SDM的特点。该模型综合了集中式管理的视图统一、操作简单等特点以及分布式管理的本地访问特点，具有较强的并行性、可扩展性和高效性，是一种适于路由器实现的高效的数据库管理模型。     

一个IPSec在Linux平台上的实现框架

提出了一个在Linux平台上实现IPSec的框架，给出了安全策略数据库(SPD)和安全关联数据库(SAD)记录的细节；分析了Linux的网络IP层的代码；给出了IPSec主要函数的原型，它们的功能和在核心的嵌入点。     

基于混合式体系结构的高速边缘路由器安全数据库的研究与实现

随着计算机网络技术的发展,对网络系统的高可靠性和高可用性提出了较高的要求,并使得网络核心设备的安全研究成为网络技术发展的热点。路由器作为网络传输的重要设备,是网络安全设计和实施的重点。高速边缘路由器作为骨干网和互联网/内部网之间的高速接入设备,在网络安全的研究中具有重要的意义。高速边缘路由器中的安全数据库管理包含了对安全策略的管理和对安全关联的管理,它的体系结构的合理性和高效性是制约高速边缘路由器系统性能的重要因素。目前,安全数据库系统普遍采用集中式体系结构完成对安全策略和安全关联数据的管理,在系统的并行性、灵活性和访问效率方面都存在着较大的缺陷;分布式管理则由于各分布子系统间的一致性维护问题在高速边缘路由器中被充分放大而无法满足高速边缘路由器的设计要求。论文基于ForCES协议框架提出了一种高速边缘路由器的体系结构CeDita,并详细分析了基于该体系结构的安全数据库混合式管理模型SDM。该模型综合了集中式管理的视图统一、操作简单等特点以及分布式管理的本地访问特点,具有较强的并行性、可扩展性和高效性,是一种适于路由器实现的高效的数据库管理模型。     

基于多核处理器的IPSec VPN系统安全策略检索研究

为满足现代高带宽互联网应用环境中的安全性保障要求,提出了一种基于Tilera　GX36多核网络处理平台的IPSec VPN系统结构,利用SDN思想设计了系统控制面和数据面的程序功能模块,实现网络流量安全的灵活控制。针对系统中安全策略检索性能要求,提出一种基于Hash的三级安全策略流表存储结构,并以各Tile CPU缓存中的安全关联流表为快速检索数据源设计一种安全策略检索方法。测试结果表明,对于互联网中典型的小包、中包和大包应用场景,该系统均能达到近40 Gb/s的处理性能。     

构建端到端的高安全政务网络——政务内网安全解决方案

针对政府的现有网络和业务的现状,我们认为一个完整的网络安全方案应该由网络层安全策略和应用层安全策略来构成,网络层安全策略主要完成对非法使用网络资源的控制,而应用层安全策略主要是针对通过合法的渠道来非法使用业务资源的控制,只有两者的完美结合,才能构成一个安全的系统! 政务内网是政府部门的内部网络,和外界网络完全隔离,所以安全问题     

基于MySQL的可定制强制访问控制的研究与实现

结合MySQL数据库系统,通过在其源代码中增加安全策略函数、修改原有数据字典、扩展SQL 语句以及建立安全策略统一管理平台的方法,实现了可定制强制访问控制机制.所实现的安全数据库原型系统使数据库安全管理员可以根据应用领域不同的安全需求灵活定义标签结构和访问规则,为增强安全数据库产品可用性、灵活性提供了一种新思路.     

数据库权限管理的一种新模式

本文从数据库管理及安全两方面介绍了一种新的基于角色的数据库权限管理模式,以Oracle数据库管理系统为例,对角色的预定义、使用、管理模式的控制方式等进行了叙述。这种新模式将更好地适应企业特定的安全策略和组织结构的调整。     

三层呵护——华为金融网络安全解决方案

金融网络的安全需要如何保证?华为公司提出的华为金融网络安全解决方案从三个层次保证了金融网络的安全。针对金融行业现有网络和业务的现状,华为公司认为一个完整的网络安全方案应该由网络层安全策略和应用层安全策略来构成,网络层安全策略主要完成对非法使用网络资源的控制,而应用层安全策略主要是针对通过合法的渠道来非法使用业务资源的控制,只有两者的     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.