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1.
攻击容忍系统通过对病毒入侵路径和频率进行扫频实现对病毒的挖掘,传统的扫频方法采用相位和频率特征匹配方法进行,对网络病毒非规则方向入侵不能起到较好的掩盖作用,扫频效果不好。提出一种采用病毒传播方向聚类分析的攻击容忍系统扫频方法,构建病毒传播路径分析模型,建立病毒传播的方向性空间搜索属性序列,分析病毒传播方向聚类演化模型,实现对病毒传播和入侵传播方向聚类过程的建模,求解病毒传播方向的聚类属性的信息熵,实现攻击容忍扫频改进算法。实验结果表明,算法能有效实现对病毒传播和扩散的时间和频率等信息进行扫频分析,病毒时频特征得到有效挖掘,通过扫频检测准确率较传统该方法提高13.6%。 相似文献
2.
《科技通报》2015,(10)
在分布式社交网络中,产生Biclique攻击信号,需要对其进行攻击延迟容忍设计,提高对病毒攻击的检测和容忍性能。传统方法中采用基于攻击信号方向性聚类延迟容忍算法,当传播路径具有发散性时,检测性能不好。提出一种基于Biclique攻击信号方向性空间搜索属性特征分解的攻击延迟容忍算法。把数据主特征建模和特征提取分类与缺省副本创建处理同步进行,得到更小的响应时间,实现攻击延迟容忍,得到基于Biclique攻击信号方向性空间搜索属性特征分解结果,进行Biclique攻击信号检测,提高对攻击信号延迟容忍性能和检测性能,仿真结果表明,采用该算进行分布式社交网络中Bi-clique攻击检测,检测性能提高34.5%,算法能有效保证分布式社交网络的安全性和对病毒攻击信号的容忍性。 相似文献
3.
针对知识发现中的模糊信息查询问题 ,提出了一种基于知识挖掘中神经网络技术的模糊信息聚类及联想设计方法。首先按照分类对信息源进行量化编码 ,然后对编码后的数据进行规整处理。对于信息聚类采用均值聚类算法 ,而模糊信息联想采用Hopfield网络实现。将基于上述算法开发出的模糊信息查询系统应用于图书信息查询 ,实验结果证明了该方法的有效性。 相似文献
4.
针对知识发现中的信息模糊查询问题，提出了一种基于神经网络的信息聚类及联想实现方法。首先按照信息分类对所要查询的信息进行量化编码，然后对编码后的数据进行规整处理。对于信息聚类采用均值聚类算法，而信息联想采用Hopfield网络实现。将基于上述算法开发出的信息模糊查询系统应用于图书信息查询，实验结果证明了该方法的有效性。 相似文献
5.
针对知识发现中的模糊信息查询问题,提出了一种基于反馈网络的模糊概念聚类及模式联想设计方法.按照分类要求对所要查询的概念集合进行量化编码,并对编码后的数据进行规整处理.对于概念聚类采用多层反馈神经网络的FP聚类算法,而概念联想采用自反馈神经网络的椭球学习算法实现.将基于上述算法开发出的信息模糊查询系统应用于图书信息查询,实验结果证明了该方法的有效性. 相似文献
6.
《科技通报》2015,(8)
新型的网络病毒的入侵和传播以正态谐振方式进行连续攻击,检测困难,需要对病毒攻击进行有效检测。传统的检测方法采用干扰攻击定位状态转移特征提取的层次性检测算法实现对病毒连续攻击的检测,算法没能自适应求解连续攻击下的特征选择参数,检测性能不好。提出一种基于窄带信号频谱偏移修正的正态谐振网络病毒连续攻击下的重叠检测算法。采用链重叠检测和向量化运算模拟正态谐振网络病毒的攻击特征和相关性质,实现对病毒的检测,通过Langevin方程描述,正态谐振网络的病毒连续攻击表现为一种双稳态非线性驱动多频共振模型,采用窄带信号频谱偏移修正方法,计算得到病毒节点连接概率以及个体的感染率,提高检测性能。仿真结果表明,该算法对病毒传播有较好的抑制性,提高了对网络病毒连续攻击下的检测性能和重叠检测能力。 相似文献
7.
《科技通报》2016,(6)
超密集网络是根据汇聚节点的拓扑属性进行测度中心加权融合的网络模型,超密集网络中容易受到类似于DOS等病毒的拒绝服务攻击。由于DOS病毒特征具有频谱混迭特性,在超密集网络难以有效识别。目前采用联合特征检测方法进行病毒攻击信息的检测识别,性能随着环境干扰影响起伏较大。提出一种基于幅频响应带宽检测的病毒攻击识别算法。进行病毒攻击的数学模型构建和信号分析,然后设计格型陷波器实现攻击信号的干扰抑制和滤波,根据病毒攻击信号的检测带宽和攻击带宽,选取不同的陷波器频率参数和带宽参数,进行频谱特征混迭加权处理,提取幅频响应特征进行病毒攻击的带宽检测,实现攻击特征识别。仿真结果表明,采用该算法对超密集网络中的病毒攻击进行幅频响应特征提取,具有较好的抗干扰性能,准确检测识别概率优越于传统算法,在网络安全领域具有较好的应用价值。 相似文献
8.
针对知识发现中的模糊信息查询问题，提出了一种基于反馈网络的模糊概念聚类及模式联想设计方法。首先按照分类要求对所要查询的概念集合进行量化编码，然后对编码后的数据进行规整处理。对于概念聚类采用多层反馈神经网络的FP聚类算法，而概念联想采用白反馈神经网络的椭球学习算法实现。将基于上述算法开发出的信息模糊查询系统应用于图书信息查询，实验结果征明了该方法的有效性。 相似文献
9.
恐怖人员在网络中发送恐怖信息时,根据恐怖信息来源的网络节点能够实现对恐怖人员的准确定位。恐怖人员发送恐怖信息与正常信息的属性不同,伪装性较强。利用传统的恐怖信息挖掘方法进行恐怖人员定位时,固有的恐怖信息被伪装,难以进行恐怖信息的准确挖掘,造成恐怖人员定位准确性降低。为此,提出一种基于聚类算法的网络中恐怖信息挖掘方法。在网络信息中筛选有价值的恐怖信息特征,从而为恐怖信息挖掘提供依据。利用聚类算法,对所有恐怖信息特征进行聚类处理,能够实现对网络中恐怖信息的挖掘,最终实现了对恐怖人员的定位。实验结果表明,利用该方法进行网络中恐怖信息挖掘,能够实现对恐怖人员的准确定位。 相似文献
10.
网络个体用户在遭受病毒入侵干扰下,由于病毒入侵信号对单个个体用户入侵的不确定性,难以实现对病毒的有效控制和免疫。提出一种基于自适应功率谱密度特征提取的网络个体用户遭受感染下病毒免疫滤波控制算法,首先进行网络病毒面入侵信号的模型构建,设计滤波控制算法实现对网络个体用户遭受感染下的病毒免疫控制。设计网络个体用户遭受感染下的病毒免疫模型,进行网络个体用户遭受感染下病毒入侵路径和安全属性分析。设计基于自适应功率谱密度特征提取的网络个体用户遭受感染下病毒免疫滤波控制算法,实现对用户遭受感染下的病毒入侵信号的滤波检测和控制。仿真实验结果表明,该算法能有效实现对病毒入侵路径和强度幅值的准确跟踪控制,免疫滤波效果较好,对病毒信号的检测概率提高15.7%,实时性和鲁棒性优越于传统方法,保证了网络个体用户的安全。 相似文献
11.
A research group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol-a chemical found in the skins of red grapes in red wine-can improve the sensitivity of mice to the hormone insulin according to a report in the October issue of Cell Metabolism.…… 《中国科学院院刊(英文版)》2008,22(1):14-15
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said. 相似文献
12.
《中国科学院院刊(英文版)》2008,22(1):2-3
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing. 相似文献
13.
Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors. 相似文献
14.
《中国科学院院刊(英文版)》2008,22(1)
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants." 相似文献
15.
A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007. 相似文献
16.
Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction. 相似文献
17.
Active biological molecules functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery disease diagnosis therapy new nanodevice construction.…… 《中国科学院院刊(英文版)》2008,22(1):22-22
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction. 相似文献
18.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies. 相似文献
19.
Leah A. Lievrouw 《The Information Society》2000,16(2):155-159
This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment. 相似文献
20.
Puay Tang 《The Information Society》1998,14(1):19-31
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means. 相似文献