基于机器学习的网络攻击检测综述

当前网络安全问题是一个瓶颈问题,在网络入侵检测中机器学习可以看作是为了通过学习和积累经验提高攻击检测系统的性能而建立的计算机程序。机器学习应用于网络攻击检测,对网络的大量数据进行分析并通过学习算法自动产生规则,从而使网络具有自动识别攻击的能力。本文在详细介绍网络攻击检测系统机器学习原理的基础上,对现有的各种方法进行了评述并结合网络攻击检测的应用需求,阐述了网络攻击检侧系统机器学习技术的发展方向。     

网络攻击特征库的优化设计与实现

随着网络入侵检测系统的广泛使用,作为系统核心部件的网络攻击特征库对网络入侵检测系统性能的影响越来越大。论文根据网络攻击特征库的特点对其进行了优化设计,将网络攻击特征库分解为入侵行为特征描述库和入侵确认库两个核心库,通过实验证明该设计方案可显著提高网络入侵检测系统的性能。     

指控网络攻击优势评估指标体系研究

基于复杂网络理论以及指控网络的组织结构特性等,对指挥控制网络的拓扑结构以及网络特征进行分析,给出指挥控制网络信息流通效率的主要影响因素,并据此提出网络攻击优势的概念、建立网络攻击优势的评估指标体系,用层次分析法对网络攻击优势进行了评估和分析,为指控网络攻击效果评估提供依据。     

网络攻击的分析及防范策略分析

网络技术在快速的向前发展,网络攻击已经成为了一个不可避免的问题.通过对网络攻击进行系统性的分析研究,对一些比较典型的网络攻击进行了简单的描述,最后提出了具有针对性的防范措施,以便于营造更加安全的网络环境.     

网络攻击的探索与研究

随着计算机网络入侵技术的不断发展,网络攻击行为表现出不确定性、复杂性和多样性等特点,网络攻击的研究已成为热点。笔者对己知的网络攻击的分类、常见的攻击方法进行分析,详细介绍了网络攻击的步骤,并概况了网络攻击未来的发展趋势。     

基于暗网的蠕虫早期检测技术在专用网络中的应用

为了对网络蠕虫等网络攻击行为进行早期检测,文章设计实现了一个基于暗网的可视化的早期检测系统,并采用原型设计和实际网络实验的方法,在某专用网络中进行了对比实验,结果表明该系统在专用网络中比传统入侵检测系统更早发现蠕虫等网络攻击,且时间提前量十分可观,说明基于暗网的早期检测技术在与国际互联网隔离的专用网络中有着良好的应用前景。     

基于节点置信度的攻击图分析

网络攻击图是用数学方法对网络状态进行抽象得到的图结构。对网络攻击图的分析在入侵检测及网络攻击预警方面有着广泛的应用前景。在引入网络攻击图的概念和贝叶斯网的分析方法后,可对传统的攻击图生成和分析方法进行改进并得到基于节点置信度的攻击图生成和分析方法。该方法在进行网络入侵告警的同时,能够对未来的网络入侵概率和网络入侵方向进行预测,指导安全人员对网络入侵防御进行反应。     

计算机网络攻击方法

该文介绍了计算机网络攻击的一般过程、网络攻击常用的方法及其原理,分析了网络存在的各种安全漏洞并针对这些安全漏洞而确定的网络攻击点和攻击策略。同时对当前常用网络攻击工具进行了介绍和归纳。     

抵御降质攻击的DWDM系统设计方法

为了提高光网络物理层的安全性能,提出了适当提高DWDM系统发送端单波长光功率,减弱降质攻击对光网络攻击的设想。分析了DWDM系统攻击光对光网络攻击原理,提出抗攻击理论及实施方法。用光网络系统构建了系统模型,严格按标准进行仿真,验证了提出设想的可行性。     

网络攻击追踪方法的分析与系统模型的建立

目前 ,计算机网络安全问题越来越严重。入侵检测是识别网络攻击的主要手段 ,现有的入侵检测系统可以检测到大多数基于网络的攻击 ,但不能提供对真实攻击来源的有效追踪。本文分析了IP地址追踪方法 ,结合现有的入侵检测技术提出了网络攻击源追踪系统的模型 ,阐述了该系统的体系结构和各部分的主要功能 ,给出了利用相关性分析对攻击者的攻击路径进行回溯的基本思想 ,对网络安全管理具有一定的借鉴意义。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.