结合特征选择的SAE-LSTM入侵检测模型

入侵检测系统(IDS)是计算机和通信系统中对攻击进行预警的重要技术.目前的IDS在安全检测方面存在2个问题:1)存在大量高维冗余数据及不相关特征干扰分类过程;2)现有模型多是针对早期网络攻击类型,对新型攻击适应性较差.针对这2个问题,提出了一种结合特征选择的SAE-LSTM入侵检测框架,采用融合聚类思想的随机森林特征打...     

基于CASL的入侵检测系统测试

随着网络攻击种类的不断增加,对入侵检测系统(IDS:Intrusion Detection System)应用提出了挑战,入侵检测系统测试和评价也越来越迫切.使用CASL(Custom Audit Scripting Language)语言编写测试脚本(程序),模拟真实的网络攻击(入侵),对当前典型的入侵检测系统进行了入侵特征识别测试,从而验证了入侵检测系统在典型网络环境下识别入侵行为的能力.测试结果有助于刻画人侵检测系统的功能特性,为比较各种入侵检测系统建立了参考标准.     

基于思科路由器的IPS实现

随着网络入侵事件的不断增加和黑客攻击水平的不断提高,传统的防火墙或入侵检测系统（IDS）显得力不从心,这就需要能够检测入侵行为并做出保护的系统来实现网络安全。近年来兴起的入侵防御系统（IPS）就能够实现这样的功能,它根据网络攻击的特征行为定义出相应的特征库,当检测到攻击行为时,便采取定义好的动作来保护网络的安全。低版本的思科路由器不具备IPS功能,高版本的思科路由器IOS中增加了这一功能。文中通过配置思科路由器实现入侵保护,维护网络安全。     

入侵检测中模式匹配算法的改进

随着网络攻击技术的发展和攻击手段的多样化,描述攻击行为的特征数目指数上升,检测算法的效率己成为误用检测技术的瓶颈,间接影响系统的实时性能。因而,如何改进字符串匹配的搜索算法、提高检测速度,是目前IDS研究的重点之一。本文提出了入侵检测中模式匹配的改进算法。     

基于网络的入侵检测技术研究

随着网络安全风险系数不断提高,作为最主要的安全防范手段的防火墙,已经不能满足人们对网络安全的需求。作为对防火墙及其有益的补充,入侵检测系统能够帮助网络系统快速发现攻击的发生,它扩展了系统管理员的安全管理能力,提高了信息安全基础结构的完整性。对基于网络的入侵检测技术的了解,有利于我们对基于主机的IDS、分布式IDS、智能IDS等方面的研究。     

蜜罐检测系统与IDS的结合应用

随着网络入侵类型的多样化发展,入侵检测系统IDS作为防止黑客攻击的一种主要手段,日益显示出其在构建方法、检测效率、可移植性和可升级性等方面存在着普遍的缺陷。蜜罐技术的设计可以让黑客入侵,借此收集证据,同时隐藏真实的服务器地址,这样可以弥补与改善IDS在设计上被动性的不足,为提前发现新的入侵检测规则提供有效的信息。蜜罐不直接给网络安全带来帮助,但它能收集和攻击者相关的攻击信息并分析这些信息,以此来研究攻击者和被蜜罐模仿的系统的漏洞,从而间接的为网络安全带来帮助。     

基于Snort传感器的分布式入侵检测系统在校园网络中的实验测试

在校园网中部署基于Snort传感器的分布式入侵检测系统,并进行后门木马Bdoor攻击实验测试,以检测系统是否能主动、实时地全面防范一系列的网络攻击。实验测试结果显示,基于Snort的分布式入侵检测系统可以有效检测出校园网络中由于网络攻击带来的安全问题。     

面向安全态势的权限有效性定量评估方法

针对安全态势评估领域的权限有效性评估指标, 融合网络流量、入侵检测系统(IDS)报警和扫描信息, 提出一种全新的权限有效性定量评估方法.该方法将用户权限作为安全目标, 基于网络会话构建威胁用户权限的入侵迹, 并使用Markov数学模型度量安全目标失败的平均入侵代价, 进而定量评估权限有效性. 实验结果表明,当系统遭受缓冲区溢出攻击时, 权限有效性指数接近于0.该方法能够实时评估缓冲区溢出攻击对系统权限有效性的威胁,有效监控黑客行为引起的系统安全态势变化. 与其他评估方法相比, 该方法考虑了报警之间的因果关系,降低了IDS误报以及无效入侵信息对安全态势评估精度的影响, 有助于管理员了解黑客入侵步骤、决策系统安全状况以及识别高危险的入侵路径.     

基于蜜罐技术的网络入侵检测系统协作模型的研究与实现

针对当前互联网中传统的入侵检测系统无法对未知攻击作出有效判断,而造成信息误报和漏报的问题,从入侵检测和蜜罐的基本特点出发,提出了一种基于蜜罐技术的网络入侵检测系统协作模型,通过引诱黑客入侵,记录入侵过程,研究攻击者所使用的工具、攻击策略和方法等,提取出新的入侵规则,并实时添加到IDS规则库中,以提高IDS检测和识别未知攻击的能力,进一步提升网络的安全性能.     

基于Agent的层次结构入侵检测系统模型设计

随着网络应用的不断扩展,用户面临越来越多的网络攻击,为了保障网络系统安全,需要采用更先进的入侵检测系统(IDS).将Agent技术应用于IDS中,采用主机监测Agent、网络监测Agent、控制中心Agent、预备Agent、路由追踪Agent以及相关知识库的更新与调用来保障网络安全.     

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.     

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.     

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.     

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.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.