基于SVM的网络威胁频率预测算法研究

网络安全风险评估分为定量评估与定性评估两种方法。现今的评估方法多数仅对网络安全事件进行定性的评估,不能给出网络安全风险值的定量说明,评估结果缺乏客观性、动态性和可信性。本文在深入研究风险评估理论和实验的基础上提出了一种新的网络安全定量风险评估方法--基于支持向量机SVM的网络威胁频率预测方法,构造了相应的SSVM模型,并采用仿真数据对模型进行了验证。该模型对来自某局域网IDS实测数据的网络威胁频率进行了预测,和真实值的对比说明,所提出的网络威胁预测算法是行之有效效的。     

基于威胁分析的多属性信息安全风险评估方法研究

根据信息系统风险评估模型中资产、威胁和脆弱性等基本要素,提出基于威胁分析的多属性定量风险评估方法.建立以威胁为核心的风险计算模型,通过威胁识别,威胁后果属性计算及威胁指数计算等多个步骤对信息系统的安全风险进行定量分析和评估.基于威胁的多属性风险计算模型利用多属性决策理论和方法,计算安全威胁的概率以及各种威胁后果属性值及其权重,对安全风险进行排序,提高信息系统风险评估的客观性和可度量性,为建立信息系统安全保障体系提供科学依据.     

一种优化的实时网络安全风险量化方法

准确地评估网络安全风险是提高网络安全性的关键.基于隐马尔卡夫模型的实时网络安全风险量化方法,以入侵检测系统的告警作为输入,能够实时量化网络风险值,有效评估网络受到的威胁,但仍然存在配置复杂、评估容易出现误差等问题.该文提出了优化的方法,利用参数矩阵自动生成代替手工设置,提高了准确性,简化了配置复杂度.首先将IDS告警和主机的漏洞、状态结合起来,定义攻击的威胁度来更好地体现攻击的风险,并对攻击进行分类,简化隐马尔卡夫模型的输入.其次,提出了利用遗传算法来自动求解隐马尔卡夫模型中的矩阵,定义风险描述规则作为求解的优化目标,解决隐马尔卡夫模型难以配置的问题.风险描述规则为描述网络安全风险提供了形式化的方法,利用这种规则建立的规则库可以作为风险评估方法的通用测试标准.最后,通过比较实验和DARPA 2000数据实际测试,证明文中方法能够很好地反映网络风险,量化网络面临的威胁.     

基于条件随机场的网络安全态势量化感知方法

网络安全态势感知(NSSA)是目前网络安全领域研究的一个热点问题.首次提出一种基于条件随机场的(CRFs)网络安全态势量化感知方法.该方法以入侵检测系统的报警信息作为网络安全态势感知的要素,结合主机的漏洞和状态,定义网络安全威胁度来更好地体现网络的风险,并对攻击进行分类,简化CRFs模型的输入,同时选择了有效的特征属性,通过DARPA 2000数据的仿真实验生成了明确的网络安全态势图,表明提出的方法能够很好地反映网络风险,量化网络安全态势.     

大数据时代网络安全态势感知关键技术分析

随着局域网（Local Area Network,LAN）内数据信息的不断增多,网络安全事件也呈现出高发态势,对网络安全态势感知、核心功能评估,成为网络环境安全管理的重要方向。通过DS证据合成规则、量化公式,对相关的网络安全数据作出归一化操作处理,并划分数据集,使用DS-GAElman评估模型,进行网络安全测试集的态势评估模型。实验结果表明：使用DS证据理论技术、Elman遗传算法,对网络安全测试集进行评估的准确率达80%以上,可用作网络安全的感知与维护操作。     

基于威胁传播模型的层次化网络安全评估方法

网络系统不仅面临外部和内部威胁主体的入侵,同时威胁主体会利用脆弱点间、网络组件间的相互作用关系进行威胁传播,产生严重的潜在威胁.设计合理的模型对潜在威胁进行识别、分析,并量化测度其对网络安全的影响,是当前网络安全评估所面临的主要挑战之一.针对该问题,提出了一种基于威胁传播模型的层次化网络安全评估方法.首先提出了威胁传播...     

基于战术关联的网络安全风险评估框架

电力系统网络是网络攻击的重要目标之一。为了保障电力系统的安全运行,网络管理员需要评估电力系统网络所面临的网络安全风险。现存的网络安全风险评估框架通常仅针对单一场景进行评估,不能从过多的网络安全告警中发现利用多种手段以达到目标的策略型攻击者。为应对上述挑战,文中设计了一种基于战术关联的网络安全风险评估框架,该体系利用成熟的网络安全知识库并整合重复性指标以尽可能简化使用者的输入,同时将多种网络安全系统产生的告警在战术层面关联起来,从而发现利用多种攻击手段协同的攻击方式。对高级持续性威胁(Advanced Persistent Threat, APT)攻击案例进行评估,对比结果表明,与现有的轻量级信息安全风险评估框架(Lightweight Information Security Risk Assessment, LiSRA)相比,该方法能更有效地发现高威胁风险,其鲁棒性也优于现有方法。     

关键信息基础设施风险评估方法研究

网络安全法从立法上明确了国家关键信息基础设施要在等级保护基础上实行重点保护,并要求定期进行安全风险检测评估。文章首先分析了关键信息基础设施的重要特性和安全保障要点,基于当前最新的风险评估标准模型,结合行业最佳实践,提出了基于关键信息基础设施业务特点识别关键属性,并围绕关键属性进行风险评估的方法论,给出了基于二维矩阵的风险分析实施方法、相关内容作为关键信息基础设施检查评估国家标准的重要补充,将为关键信息基础设施安全评估工作的执行提供参考。     

工业控制系统风险评估要素量化方法

风险评估是保障工业控制系统安全的重要手段之一,在风险分析原理的基础上,对其中的资产、安全措施、威胁、脆弱性等关键要素给出了相应的量化方法。通过对相关风险要素进行细致的量化,有利于降低风险评估过程中的主观性,提高评估结果的合理性、准确性。     

基于FPP的网络安全风险量化评估研究

针对风险评估过程的不确定性,本文提出了一种基于模糊偏好规划法的网络安全风险综合评估模型。利用层次分析法确定各种风险因素相对重要性的评价区间,应用模糊偏好规划法处理风险因素的相对有效性量化评估,增强了评估准确性。通过评估实例分析可知,该模型可以方便地应用于网络安全风险评估,实验结果符合实际。     

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.