基于SOFM的入侵检测技术研究

通过引入自组织特征映射神经网络,提出了一种智能化的入侵检测技术。仿真实验表明,该方法完全可以运用于入侵检测系统之中,并有助于提高入侵检测系统的性能和网络的安全性。     

基于贝叶斯理论的入侵检测评测方法研究

提出一种基于贝叶斯理论的入侵检测系统(IDS)评测方 法, 设计并建立了一套较完善的入侵检测系统评测体系. 确立了用于评测IDS的4个重要指标：功能指标、 性能指标、 安全性指标和用户可用性指标. 量化分析了一些主要测试指标, 并利用概率树模拟入侵及检测过程. 结果表明, 该方法能在系统的检测率和误报率间找到最佳的阈值平衡点.     

分布式入侵检测系统安全通信研究

当前入侵检测系统的研究存在一些不足之处,如其层次化的入侵数据分析结构使检测效率低、缺少对1DS自身的安全性考虑等,难以适应新的网络环境的需要.针对这些问题,将密码学运用到入侵检测系统中,实现入侵检测系统的安全;将agent技术和P2P技术应用到研究中,实现高效的分布式入侵检测系统.给出系统的设计与实现方法,并对系统的安全性和性能进行了分析.     

基于Agent的分布式人侵检测系统

入侵检测是网络安全的一个重要方面,在公共入侵检测框架的基础上,提出了基于Agent的分布式入侵检测系统,并给出了该入侵检测系统的系统模型.具有良好的分布性、可扩展性、实时响应等优点.并引入了贝叶斯推理的统计方法对检测结果进行分析,优化了系统结构,提高了检测效率.     

入侵检测规则动态生成研究

在入侵检测研究领域中,提高检测模型的检测率并降低误报率是一个重要的研究课题.本文提出了一种针对网络入侵检测事务流的实时动态规则生成方法.该方法解决了当前主流关联规则生成算法应用到入侵检测过程中存在的多遍扫描、大量无效规则和频繁集产生等问题.实验结果表明,文中所提出的方法在规则动态生成和对网络异常情况的检测方面都显示出比较好的性能,相对Snort入侵检测系统,平均提高10%左右的检测精度,克服了Snort系统在异常检测方面的局部缺陷.     

基于Agent自适应分布式入侵检测系统

入侵检测是网络安全保护体系中的一个重要组成部分,针对目前入侵检测系统不具备自适应性的情况,该文引入了一种入侵检测系统的自适应策略,并提出一种基于Agent自适应分布式入侵检测系统.分析了各组成模块结构、功能特点以及模块之间的协作关系,并阐述了该系统设计中的信息表示及所采用的通信协议.该系统具有良好的扩展能力、自学习功能,能够实现分布式的入侵检测.     

自适应入侵检测系统

论述入侵检测系统的基本概念,分析入侵检测系统(IDS)的关键技术及存在的问题.为了解决传统入侵检测模型所存在的问题,提出了一个自适应入侵检测系统(AIDS)模型,阐述了系统模型的结构及主要功能.运用自适应的模型生成方法,使收集数据、建立模型并将模型分配给检测器的过程高效、自动化.该模型为开放的系统模型,具有很好的可伸缩性,可大大减少使用IDS的代价,解决IDS的环境适应性问题,降低建立模型的代价,提高系统的效率.     

一种基于移动agent的入侵检测系统框架研究

提出了一种新结构———基于移动agent技术的IDS,并对此结构的优缺点作了详细的分析,对研究基于移动代理技术的入侵检测系统具有一定的指导作用.MA IDS采用移动agent技术共同合作处理每个被监控主机的信息,然后完成全局入侵者行为的信息提取.主要讲述了系统的结构模型和系统各个组件的功能,最后讨论了系统的特点和有待改进的地方.     

深度防卫的自适应入侵检测系统

为了全面检测黑客入侵和有效提高检测精度,提出了一种深度防卫的自适应入侵检测系统模型.该模型按照黑客入侵对系统影响的一般顺序,使用不同方法对网络行为、用户行为和系统行为3个层次涉及到的网络数据包、键盘输入、命令序列、审计日志、文件系统和系统调用进行异常检测,并利用信息融合技术来融合不同检测器的检测结果,从而得到合理的入侵判定.在此基础上,提出了系统安全风险评估方法,并由此制定了一种简单、高效的自适应入侵检测策略.初步实验结果表明,所提的深度防卫自适应入侵检测模型能够全面、有效地检测系统的异常行为,可以自适应地动态调整系统安全与系统性能之间的平衡,具有检测精度高、系统资源消耗小的优点.     

基于句法模式识别的异常入侵检测技术研究

针对异常入侵检测存在的准确性差、速度慢的问题,提出一种基于句法模式识别的异常检测技术.该方法将句法模式识别技术应用到入侵检测中,通过该技术对结构的强大描述和识别能力,提高入侵检测的准确性和速度;描述了如何用句法模式识别技术建立程序执行的正常模型,以及如何使用模型检测入侵;并通过实验,验证了方法的有效性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.