随心所欲安全游

对于中大型企业,包括服务供应商和数据中心,每天处理和传输的数据在飞速增长,为达到令人满意的服务水平质量,特别需要高性能设备提高处理能力。另外,这些数据因与业务相关,还需要得到安全保护。然而,任何安全保护都会占用系统资源,降低数据处理效能。这就要求企业用户在选择安全解决方案时必须注重处理能力。为此,诺基亚推出一系列高性能安全方案:IP 2250、IP 1220和IPSO 3.8。     

IP地址的安全防范技术在校园网中的应用

随着Internet的飞速发展,网络信息安全问题也越来越重要。该文分析了IP地址盗用的常用方法。并对如何实现校园网的安全运行和IP地址的安全防范技术加以讨论。     

IPv6安全功能的探讨

新一代ＩＰ协议（ＩＰｖ６）为了提高网络的安全相关的协议中规定了与安全相关的必须执行的规范。该文首先介绍ＩＰ协议的安全体系结构,然后介绍与安全有关的扩展头标及其实现过程,最后介绍ＩＰｖ６安全方面的应用情况及展望。     

宽带IP城域网安全解决方案

网络系统的安全解决方案可以保护系统免受侵犯，消除网络系统中的安全漏洞， 保 障网络服务，是城域网建设中的重要内容。分析了宽带IP城域网安全解决方案的要素， 并根据笔者的经验，对宝安信息网的安全解决方案进行了论述。     

设计安全的Linux网络

网络作为一个系统,其安全性在计划网络拓扑时就应该仔细考虑,制订安全性策略。此后在网络实施和维护的每一个举措都应该严格执行安全策略。在企业的网络中,Linux现在较多地扮演防火墙/路由器或服务器等重要角色,Linux系统的安全决定了整个网络的安全与否。因此,了解相关的技术,并对Linux系统进行安全设置是至关重要的。     

电信IP承载网安全防御

IP承载网的安全防御是保障电信运营商网络安全的关键,也是信息安全领域的一个热门课题。本文首先分析了IP承载网面临的安全风险,然后介绍了完善的安全体系架构,并提出了一个基于安全域、有针对性地部署安全防御策略的解决方案。     

无线局域网中的信息安全保护和安全漫游

在描述无线局域网中现有安全机制的基础上,提出了一个比较全面的信息安全保护和安全漫游解决方案。采用RADIUS和ESSID认证、MAC地址过滤、WEP加密并动态生成WEP密钥(128位加密密钥)等机制,来保护用户数据的私密性;采用基于MobileIP和RADIUS协议的漫游机制来支持用户在多个接入点之间的漫游,保证用户在进行安全漫游时不中断业务。     

诺基亚IP安全解决方案Nokia IP2250

6月21日诺基亚宣布推出新的高端IP安全平台诺基亚IP2250。这款产品扩展了诺基亚的高性能网络安全设备产品系列．其设计是用来便捷地处理大中型企业．服务供应商和数据中心日益增长的．大流量的数据通信，而且这款产品都将安装诺基亚网络安全操作系统——IPSO 3．8。该操作系统将大幅度提升诺基亚整个IP系列安全平台的性能．IP2250性能更加卓越，     

IPV6安全机制分析

IPV6是新一代网络互联协议,它比IPV4能提供更多的地址空间,提供更安全的服务。本文简单介绍了IPV6的IP Sec安全协议,并分析了IPV6存在的安全问题。     

IP网络安全测试研究

确保IP网络安全成为目前必须解决的问题,而解决这个问题的关键一步则是IP网络安全测试,只有IP网络安全测试合格,网络安全才有可能性.本文对网络安全测试进行了详细和系统的介绍,争取让每个读者都能有详细的了解,并且对网络安全测试内容和网络安全测试方法进行了明白的描述,能够帮助不了解的人加深了解.     

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.     

An Analysis of the Criteria for Evaluating Adequate Theories of Computation

This paper deals with the question: What are the criteria that an adequate theory of computation has to meet? (1) Smith’s answer: it has to meet the empirical criterion (i.e. doing justice to computational practice), the conceptual criterion (i.e. explaining all the underlying concepts) and the cognitive criterion (i.e. providing solid grounds for computationalism). (2) Piccinini’s answer: it has to meet the objectivity criterion (i.e. identifying computation as a matter of fact), the explanation criterion (i.e. explaining the computer’s behaviour), the right things compute criterion, the miscomputation criterion (i.e. accounting for malfunctions), the taxonomy criterion (i.e. distinguishing between different classes of computers) and the empirical criterion. (3) Von Neumann’s answer: it has to meet the precision and reliability of computers criterion, the single error criterion (i.e. addressing the impacts of errors) and the distinction between analogue and digital computers criterion. (4) “Everything” computes answer: it has to meet the implementation theory criterion by properly explaining the notion of implementation.     

一种面向查询的多文档摘要方法

面向查询的多文档摘要技术有两个难点 第一,为了保证摘要与查询密切相关,容易造成摘要内容重复,不够全面;第二,原始查询难以完整描述查询意图,需进行查询扩展,而现有查询扩展方法多依赖于外部语义资源。针对以上问题,该文提出一种面向查询的多文档摘要方法,利用主题分析技术识别出当前主题下的子主题,综合考虑句子所在的子主题与查询的相关度以及子主题的重要度两方面因素来选择摘要句,并根据词语在子主题之间的共现信息,在不使用任何外部知识的情况下,进行查询扩展。在DUC2006评测语料上的实验结果表明,与Baseline系统相比,该系统取得了更高的ROUGE评价值,基于子主题的查询扩展方法则进一步提高了摘要的质量。     

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.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

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.     

Impact of cognitive theory on the practice of courseware authoring

Abstract The cognitive revolution has yielded unprecedented progress in our understanding of higher cognitive processes such as remembering and learning. It is natural to expect this scientific breakthrough to inform and guide the design of instruction in general and computer-based instruction in particular. In this paper I survey the different ways in which recent advances in cognitive theory might influence the design of computer-based instruction and spell out their implications for the design of authoring tools and tutoring system shells. The discussion will be divided into four main sections. The first two sections deal with the design and the delivery of instruction. The third section analyzes the consequences for authoring systems. In the last section I propose a different way of thinking about this topic.     

CONFLUENT POSSIBILITY DISTRIBUTIONS AND THEIR REPRESENTATIONS

Possibilistic distributions admit both measures of uncertainty and (metric) distances defining their information closeness. For general pairs of distributions these measures and metrics were first introduced in the form of integral expressions. Particularly important are pairs of distributions p and q which have consonant ordering—for any two events x and y in the domain of discourse p(x)⪋ p(y) if and only if q(x) ⪋ q(y). We call such distributions confluent and study their information distances.

This paper presents discrete sum form of uncertainty measures of arbitrary distributions, and uses it to obtain similar representations of metrics on the space of confluent distributions. Using these representations, a number of properties like additivity. monotonicity and a form of distributivity are proven. Finally, a branching property is introduced, which will serve (in a separate paper) to characterize axiomatically possibilistic information distances.     

CCD camera modeling and simulation

In this paper we propose a modeling of an acquisition line made up of a CCD camera, a lens and a frame grabber card. The purpose of this modeling is to simulate the acquisition process in order to obtain images of virtual objects. The response time has to be short enough to permit interactive simulation. All the stages are modelised: in the first phase, we present a geometric model which supplies a point to point transformation that provides, for a space point in the camera field, the corresponding point on the plane of the CCD sensor. The second phase consists of modeling the discrete space which implies passing from the continous known object view to a discrete image, in accordance with the different orgin of the contrast loss. In the third phase, the video signal is reconstituted in order to be sampled by the frame grabber card. The practical results are close to reality when compared to image processing. This tool makes it possible to obtain a short computation time simulation of a vision sensor. This enables interactivity either with the user or with software for the design/simulation of an industrial workshop equipped with a vision system. It makes testing possible and validates the choice of sensor placement and image processing and analysis. Thanks to this simulation tool, we can control perfectly the position of the object image placed under the camera and in this way, we can characterise the performance of subpixel accuracy determining methods for object positioning.     

Gain-scheduled H ∞ filtering of parameter-varying discrete-time systems via parameter-dependent Lyapunov functions

This paper is concerned with the problem of gain-scheduled H _∞ filter design for a class of parameter-varying discrete-time systems. A new LMI-based design approach is proposed by using parameter-dependent Lyapunov functions. Recommended by Editorial Board member Huanshui Zhang under the direction of Editor Jae Weon Choi. This work was supported in part by the National Natural Science Foundation of P. R. China under Grants 60874058, by 973 program No 2009CB320600, but also the National Natural Science Foundation of Province of Zhejiang under Grants Y107056, and in part by a Research Grant from the Australian Research Council. Shaosheng Zhou received the B.S. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1992, July 1996 and October 2001, from Qufu Normal University and Southeast University. His research interests include nonlinear control and stochastic systems. Baoyong Zhang received the B.S. and M.Sc. degrees in Applied Mathematics, in July 2003 and July 2006, all from Qufu Normal University. His research interests include and nonlinear systems, robust control and filtering. Wei Xing Zheng received the B.Sc. degree in Applied Mathematics and the M.Sc. and Ph.D. degrees in Electrical Engineering, in January 1982, July 1984 and February 1989, respectively, all from the Southeast University, Nanjing, China. His research interests include signal processing and system identification.