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21.
基于系统调用特征的入侵检测研究   总被引:11,自引:1,他引:11  
姚立红  訾小超  黄皓  茅兵  谢立 《电子学报》2003,31(8):1134-1137
对网络服务程序进行攻击是非法用户入侵系统的主要途径 ,针对关键程序的入侵检测近年来受到重视 .该文提出的CTBIDS检测模型在利用系统调用特征树描述程序行为特征的基础上 ,通过异常有限积累判别程序入侵 ,既能体现异常状况的长期积累 ,也能很好地反映入侵的异常局部性原理 .此外 ,该文通过统计分析方法确定入侵判别参数 ,使得入侵判别更加准确 .测试及试用结果表明CTBIDS能有效检测出针对关键程序的攻击  相似文献   
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为了提高抽样检验的检出率,基于对某运营商呼叫中心服务质量管理现状的分析,提出利用BP神经网络对客服代表输出的话务质量进行风险评估和预判分类的方法。经过Matlab仿真平台的模拟实验,确定风险因子和风险等级,并进行数据归一化处理,建立数学模型,得到结论:BP神经网络技术应用于呼叫中心服务质量风险评估和抽样检验领域是可行的、有效的。基于该方法,可以将呼叫中心服务质量抽样检验的检出率从传统方法的5.3%提高到现在的9.23%,提高了质检人员的工作效率。  相似文献   
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Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed.  相似文献   
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Electrochemical blocking is a type of single-entity electrochemical measurement particularly well adapted to the detection of insulating particles. The digital detection of ultralow concentrations of artificial entities such as polymer particles or biotargets such as proteins and bacteria represents an exceptional opportunity for sensing applications. In this review, we explore the latest development in the field of electrochemical blocking and propose some perspectives.  相似文献   
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An efficient red phosphorescent organic light emitting diode (PhOLED) has been realized by utilizing a composite hole transporting layer comprised of all-inorganic cesium lead halide perovskite CsPbBr3 via spin-coating and 1,3-bis(9-carbazolyl) benzene (mCP) by vacuum depositing, in which CsPbBr3 film is used as a hole transporting layer and mCP plays a dominant role in electron and exciton blocking. And this PhOLED shows a saturated red emission coordinated at CIE (0.65, 0.33) driven at 7.5 V, a maximum brightness of 20,750 cd/m2, and a maximum current efficiency of 10.64 cd/A, which is as 1.87 times as that 5.68 cd/A of the reference PhOLEDs based on traditional small organic molecular hole transporting material N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzi (NPB). The electroluminescent (EL) spectra and the energy level alignment of different PhOLEDs are investigated. The enhanced EL performances are ascribed to improved hole injecting and transporting behaviors, and better electron and exciton confinements by introducing the composite hole transporting layer CsPbBr3/mCP.  相似文献   
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In this letter, lateral GaN-based Light Emitting Diodes (LEDs) with a SiO2 current blocking layer (CBL) buried in the indium tin oxide (ITO) film and highly reflective metal materials have been proposed. Compared with the conventional CBL structure which was inserted between ITO film and p-type GaN, simulation results showed that LEDs with a buried CBL in the ITO film effectively facilitated current spreading under the CBL. We demonstrated that buried CBL was beneficial for suppressing current crowding (CC) effect around the edge of CBL and may facilitate higher LED efficiency. Furthermore, experimental results showed that LEDs with the buried structure we proposed showed lower working voltage and higher light output power (LOP) compared with those with conventional CBL structure. These results further confirmed that the buried CBL scheme was effective to reduce current crowding (CC) effect. In addition, highly reflective metal materials of Cr/Al/Pt/Au were employed to reduce light absorption and achieve high light extraction efficiency.  相似文献   
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Satellite and terrestrial components of IMT?Advanced need to be integrated so that the traditional strengths of each compo?nent can be fully exploited. LTE/LTE?A is now a recognized foundation of terre...  相似文献   
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基于GSM多功能基站的手机终端接入功能,实现其语音通信功能。首先开通基站的语音呼叫业务,然后将原始语音形成语音发送脉冲,最后将手机锁定在基站工作,对语音功能进行测试。根据多功能基站的功能和性能要求,不仅实现其语音通信功能,且使之具有呼叫异常处理能力,功能设计上相对商用基站也作了一些改进。实验证明:锁定在多功能基站工作的手机能收到基站发送的语音信息。  相似文献   
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