一种面向SSL VPN的新型应用层访问控制模型

利用虚拟私有网（VPN：Virtual Private Network）来实现安全跨越Internet访问远端服务群的技术是目前网络安全研究的一个重要组成部分。但是,由于虚拟私有网的隧道技术能够绕过防火墙,使得基于VPN服务器攻击内部服务群成为可能。因此,本文提出了一种面向VPN的新型访问控制模型——应用层集中式信息访问控制模型。它综合了目前主流访问控制模型的控制特点、反病毒和入侵检测的工作机制。并针对VPN通信流的特点,将访问控制与VPN隧道、转发机制紧耦合,从而增强网络安全性。同时,本文给出了该模型的一个实现原型。     

分布式防火墙与代理服务器技术相结合的安全性文件存取研究

本文研究以企业组织内部网络的文件安全性为范围,结合分布式防火墙技术在封包层次的过滤与控制功能,以及代理服务器在应用层次的存取分析与控制功能,辅以传统的SSL安全联机及VPN虚拟私有网络技术,并以使用者的应用为导向,来控制网络行为,以形成一个多层次的安全性文件存取机制。     

入侵检测与防火墙协同应用模型的研究与设计

防火墙与入侵检测系统作为两种网络安全防护技术应用的越来越广泛。本文在简要介绍防火墙与入侵检测的优点与不足的基础上,提出了在网络中同时部署防火墙与入侵检测系统,使它们各自发挥所长来保护内部网络的安全。并通过SHELL脚本将IDS检测到的入侵行为自动生成防火墙的规则,及时的阻断来自外网的入侵行为,使IDS与Firewall能够有效的协同工作,从而提高网络的安全性。     

防火墙与入侵检测系统结合的安全模型设计

近年来,入侵检测系统（IDS）作为一种积极主动的安全防护技术得到了广泛的重视,被认为是防火墙之后的第二道安全闸门。本文从多方面对防火墙与IDS的特性进行了分析,提出了一种防火墙与IDS互动的安全模型,并给出了一个实例,以使网络的安全防御能力大大提高。     

浅谈如何实现入侵检测系统安全防护

入侵检测系统（Intrusion Detection System,IDS）是一种主动防御型安全技术,是防火墙的合理补充。它改变了传统网络安全防护体系被动防守的局面,使网络安全防护变得更积极、主动。     

防火墙脆弱性分析及对策研究

阐述了防火墙技术原理,分析了其安全脆弱性,介绍了容入带防火墙入侵检测技术（IDS）的VPN,设计了防火墙技术体系结构,并提出了应对常见攻击方式的策略。     

虚拟专用网络技术及其应用(下)

虚拟专用网发展方向及应用展望 隧道交换技术 隧道交换是3Com公司为了增强VPN的安全性、可管理性、VPN性能及可扩展性而开发的一种新技术。它通过单一的网络边缘设备将多个VPN引入到网络中,对VPN流量进行有效会聚并加以传递,而且可以根据需要灵活确定其终端节点。 现有的VPN技术都是在专有网络的边缘——防火墙以外或两道防火墙之间的非军事区(DMZ)结束隧道,而隧道交换技术的采用,使VPN可以安全地跨越防火墙,延伸到企业网内部特定的隧道终端。从外部来看,所有的隧道流量都被引导到隧道交换     

无线传感器网络中基于博弈论的入侵检测系统

由于无线链路的开放性,节点生存周期有限,网络拓扑结构动态变化,传统的基于防火墙的安全策略作用有限,使得无线传感器网络（WSNs）存在严重的安全性问题。入侵检测系统IDS（Intrusion Detection System）作为一种主动防御方式,成为了当前研究的热点问题之一。论文针对目前IDS发展现状,采用基于博弈论的分析方法,建立可应对多目标、多攻击源和多攻击强度的IDS模型,使在对攻击的防御成功率和延长网络生存周期上都有所改进。     

虚拟专用网络技术(VPN)在大学校园网中应用

虚拟专用网络（VPN）是实现在公网上安全传输私有网络信息的一种技术，VPN技术在校园网中的应用，提高了校园网的可管理性，灵活性和安全性。     

VPN中的动态端点准入控制机制研究

传统VPN的接入控制依赖于身份认证,而未考虑终端环境的动态变化,未能将客户终端的安全融入到VPN结构中去.本文提出DEAC（Dynamic Endpoint Admission Control,动态端点准入控制）机制,将终端安全状况和整个VPN系统相关联,使得VPN能够感知客户终端环境的变化,依靠具体情况动态实施访问控制;由终端环境和VPN服务构成一个整体,提高VPN拓扑的安全性.     

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.