弱关联规则下的联合数据库入侵检测方法研究

联合数据库的入侵和普通入侵不同,其无显著的行为特征,入侵数据属性差异较大,很难形成统一的约束规范,导致传统的入侵检测方法,由于通过提取入侵行为特征进行入侵检测,无法有效且准确地完成联合数据库的入侵检测,提出一种弱关联规则下的联合数据库入侵检测方法,通过弱关联模式在联合数据库中支持程度与联合数据库记录总量的比求出弱关联模式的支持度,获取频繁弱关联模式集,采用改进的双置信度算法对频繁弱关联模式集的置信度进行计算,获取弱关联规则,依据弱关联规则,通过原始联合数据库对分类超平面进行计算,采用该超平面完成联合数据库的整体分类,采用主成分分析方法对联合数据库中的操作数据进行降维处理,通过差异分类方法,对联合数据库中的操作数据特征进行分类操作,实现弱关联规则下联合数据库的有效入侵检测。实验表明,所提方法具有很高的准确性及有效性。     

基于稀松模糊定位算法的网络入侵特征检测

提出了一种基于稀松模糊定位算法的网络入侵特征检测算法。新算法通过采集初始网络入侵特征,组建特征集合。利用稀松运动特征匹配算法最大程度上纠正由于特征模糊带来的弊端。保证跟踪匹配过程中,运用较少的入侵特征点完成后期的多个匹配,大幅降低匹配时间,消除匹配误差问题,通过将全局搜索和局部搜索机制有机地结合,保证检测的准确性。实验结果表明,利用本文算法进行入侵检测,能够有效提高检测的准确性。     

利用混沌特征分析的大型Web数据库异常检测

为研究使用混沌分析的方法检测大型Web数据库的异常入侵特征新型问题,提出使用递归图分析的混沌特征分析方法检测Web数据库异常入侵。使用平均互信息算法和虚假最近邻点算法求取Web数据库信息流相空间重构的关键参数,使用递归图分析方法分析了各类异常入侵信号下真实Web数据库的检测。仿真结果表明平均互信息算法和虚假最近邻点算法能有效应用于对Web数据库信息流异常信号入侵检测的相空间重构中。递归图混沌分析的方法能有效检测出各类异常入侵特征,递归图中有规则图案,表明入侵信号和Web数据库信息流具有确定性成分存在,能对之实现有效检测和防御,研究结果证明检测算法能有效应用于网络数据安全检测实践。     

大数据环境下网络主动入侵海量数据的检测方法研究

提出基于半监督混合模型的海量入侵数据检测方法。利用蚁群算法进行入侵数据的特征选择,在结合半监督的混合模型分类方法进行入侵数据的分类,利用混合模型对数据样本空间的聚类分布进行描述,利用数据函数将聚类的信息与分类算法相结合,进行数据分类时对没有标示的数据样本进行考虑,对入侵数据进行检测。克服传统方法存在的弊端,提高了分类器的泛化能力,保证数据分类的效果,提高了入侵数据检测的准确性,完成对大数据环境下网络主动入侵海量数据检测的研究。实验的结果表明,利用本文方法能有效地提高入侵数据检测的准确性。     

大型多媒体网络数据库异常数据高效检测方法

大型多媒体网络数据库汇聚了大量文本、图片、视频、音频等多种媒体资源,并通过云存储系统实现资源共享。在大型多媒体网络数据库中,异常数据给数据库带来安全威胁和存储开销,对其高效检测保证数据库系统的稳定运行。传统的检测方法采用模糊FCM检测算法,具有移植性不好的弱点,检测性能不好。提出一种基于密度先验信息滑动时间窗口重排的大型多媒体网络数据库异常数据高效检测方法,构建大型多媒体网络数据库异常数据高效检测模型,并与传统算法进行检测性能对比,仿真结果表明,采用该算法进行网络数据库的异常数据检测,能有效提高对异常数据的检测性能,检测概率优于传统算法,开销缩小,实现高效检测。     

基于弱关联数据修补技术的数据库优化查询算法

在一些大型的数据库中,数据的种类和数量形成海量,一些复杂的强冗余数据给需要查询的关联数据带来了干扰,一旦干扰过大,会造成关联属性弱化,挖掘耗时,严重影响数据库查询的准确性和高效性.为了解决此问题,提出一种基于弱关联数据修补技术的数据库优化查询算法,在数据查询过程中,利用关联查询过程中实时数据对之前的数据进行关联修补;然后利用可修复的关联特征建立最有可能的数据关联,从而进一步地完成对海量数据弱关联环境下的数据库优化查询.实验表明,该方法能够较好地完成弱数据的关联,提高了查询的效率.     

数据库被破坏后入侵路径恢复模型分析仿真

当前所有的对数据库入侵检测研究以后期入侵特征提取为主,忽略了对原始入侵路径的研究,研究数据库被入侵的路径对数据库的安全防范有着重要意义。为此,提出基于入侵路径信息关联思维的数据库被破坏后入侵路径恢复方法。计算入侵路径数据属性的差异性和其对应的权重,实现入侵路径数据的特征提取。针对入侵路径数据进行人工免疫,在人工免疫的过程中需要计算抗原和抗体的匹配度,获取入侵路径数据的关联性,重构入侵路径数据的集合,实现了数据库被破坏后入侵路径的恢复。实验结果表明,利用该算法进行数据库被破坏后入侵路径的恢复,能够提高恢复效率,获取准确的入侵路径数据,为数据库的安全提供了保障。     

一种网络多次变异信息入侵检测算法

提出了一种基于变异特征自动机匹配的网络变异信息入侵检测算法.通过提取网络中的异常参数,利用异构数据匹配计算,对发生变异的网络数据特征项进行多次二叉树的建立,分类计算连续变异随机变量服从节点分布,准确对变异特征和非变异特征进行区分.实验表明,该算法提高了网络变异信息入侵检测的准确率,取得了不错的效果.     

外部多网络对抗中注入性入侵的检测模型

在网络对抗中同时存在多种注入性入侵的情况下,需要及时准确地检测出入侵的恶意程序。传统的检测方法需要提取数据库中所有恶意程序样本特征参数进行比对,由于外部注入的恶意程序的与传统入侵特征不同,伪装水平较高,使得恶意程序特征与正常程序特征难以分别,检测结果准确性降低,导致军事网络安全受到严重威胁。为此,提出一种基于特征优化算法的外部多网络对抗中注入性入侵检测方法。根据主要特征分析方法,能够得到注入性入侵恶意程序的主要特征,利用注入性入侵特征映射条件,能够得到注入性入侵的检测模型,实现了网络对抗中注入性入侵的检测。实验结果表明,利用该算法能够准确的检测出网络对抗中注入性入侵的恶意程序,效果令人满意。     

多模式匹配算法的应用与改进

本文针对入侵检测中多模式匹配算法,提出的观点。在计算机网络安全行业起到提升检测效率作用。如付诸现实将减少入侵检测系统规则库特征值匹配时间。随着互联网的快速发展,Linux操作系统得到广泛应用的同时网络入侵的攻击手段也在不停变化,入侵检测系统可将捕捉到的数据包与已知的网络入侵特征库进行比对,进而发现入侵行为。AC算法是多模式匹配算法之一,它的优点在于能同时进行多个模式串的匹配搜索,缺点是会出现多次没有必要的比较,影响了入侵检测系统的效率,为了提高匹配效率,本文根据AC算法的有限状态自动机构建原理,利用BM算法的跳跃思想,优化文本串位移,提出了一种双向AC算法和BM算法结合的改进算法。根据实验结果表明此算法有效的降低了匹配时间。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

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.     

Cooler temperatures inductive to locust outbreaks

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.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

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.     

Low doses of a red wine ingredient figh diabetes in mice

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.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

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.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

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.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Molecular motor assembly of a biomimetic system

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.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence