一种基于小波的网络流量发生器设计

网络流量发生器在网络性能分析和协议实现中具有重要的作用。文章基于多分形小波模型，设计了一种自相似网络流量发生器。其中对随机数的生成、序列的截断、自相似序列的生成以及自相似流量的生成等主要设计部分进行了论述。与常用的基于分形布朗运动的模型的流量发生器相比，该发生器生成的流量具有更准确的自相似流量特性。     

基于卷积神经网络的Android流量分类方法

深度学习就是机器学习研究的过程,主要通过模拟人脑分析学习的过程对数据进行分析。目前,深度学习技术已经在计算机视觉、语音识别、自然语言处理等领域获得了较大发展,并且随着该技术的不断发展,为网络流量分类和异常检测带来了新的发展方向。移动智能手机与大家的生活息息相关,但是其存在的安全问题也日益凸显。针对传统机器学习算法对于流量分类需要人工提取特征、计算量大的问题,提出了基于卷积神经网络模型的应用程序流量分类算法。首先,将网络流量数据集进行数据预处理,去除无关数据字段,并使数据满足卷积神经网络的输入特性。其次,设计了一种新的卷积神经网络模型,从网络结构、超参数空间以及参数优化方面入手,构造了最优分类模型。该模型通过卷积层自主学习数据特征,解决了传统基于机器学习的流量分类算法中的特征选择问题。最后,通过CICAndmal2017网络公开数据集进行模型测试,相比于传统的机器学习流量分类模型,设计的卷积神经网络模型的查准率和查全率分别提高了2.93%和11.87%,同时在类精度、召回率以及F1分数方面都有较好的提升。     

基于Fourier变换的网络流量建模仿真

文章以自相似流量模型FBM模型为研究重点,在分析以往产生自相似序列生成算法RMD算法的优缺点上,采用基于Fourier变换的DTFT算法生成自相似序列。最后应用自相似流量的检测算法R/S算法,对其结果进行了详细分析,DTFT算法兼顾了RMD算法的简单、快速更具有准确度高、稳定性好的特点,更适合对复杂多变的网络流量的仿真。     

基于SARIMA-LSTM组合模型的网络流量预测方法

针对网络流量预测问题，提出一种基于SARIMA和LSTM组合模型的网络流量预测方法。首先，利用S-HESD算法对异常流量数据进行检测，并通过滑动窗口均值进行数据平滑处理；然后，利用基于统计学习的SARIMA模型预测流量数据，并将其作为LSTM神经网络的输入，最终输出流量预测值。实验结果表明，SARIMA-LSTM组合模型能充分呈现骨干网、城域网、边缘接入网等不同层级网络的周期性和趋势性等特点，优于SARIMA、LSTM等单一模型。     

基于领域知识内嵌的深度学习网络流量预测研究

首先针对流量数据可能存在的时域分布突变问题设计了一种基于JS散度的异常检测算法，以获得能够反映流量变化规律的数据。而考虑到网络流量的自相似性、长时相关性和周期性特点，提出一种基于卷积生成网络和自适应注意力元网络组成的动态时域生成流量预测模型（GDTN），能够有效地降噪、生成和预测流量数据，并根据不同输入条件动态分配不同多时域流量特征的重要性。最后在智能城域网端口数据集上进行实验，验证了该算法相比于多种经典时序预测算法在预测准确度、存储资源占用和时间效用等方面具备明显优势。     

基于关键链路优先的光网络流量疏导保护策略

针对当前网络流量拥堵严重的问题,分析了其形成原因.提出了关键链路的概念.采用了一种基于关键链路优先的网络流量疏导保护策略.利用空闲波长的大小实现对关键链路的监控.策略性地让业务流量避开网络中的关键链路.通过NSFnet网络拓扑进行算法仿真,结果表明有较低的阻塞率.和传统算法相比,该算法可以有效降低网络流量堵塞故障.     

自相似网络流量模拟的分布式系统的设计与实现

 随着网络应用的发展,网络流量不断加大,对于网络应用系统的测试也占有越来越重要的地位.良好的网络流量模型能较为真实的反映网络的情况,并能给与应用系统更为全面的测试.根据统计学的结果表明,网络流量在时间上具有自相似性.因此,对自相似流量模型的研究十分重要.为了克服单机生成网络流量的不足,本文对于分形高斯噪声(FGN)模型的算法进行了改进,使其能够并行且高速的生成自相似样本.文中针对改进后的算法提出了分布式系统,并阐述了系统的整体结构和控制机制的设计与实现.本文的工作还包括实现了一个检测网络流量的检测端,并通过它来分析分布式系统所生成的样本.结果表明,本系统所生成的网络流量具有自相似性.     

基于集成深度神经网络流量预测的动态网络切片迁移算法

针对5G网络切片(NS)场景下由于缺乏提前对物理网络资源进行感知而导致切片迁移滞后的问题,该文提出一种基于集成深度神经网络流量预测的动态切片调整和迁移算法(DSAM)。首先建立了基于计算、内存、带宽资源配置的网络总惩罚模型;其次,提出基于集成深度神经网络的流量预测算法预测未来网络流量情况,并根据流量类型的不同将其转换成对未来时刻物理网络的资源占用及切片的资源需求感知;最后,根据感知结果,以尽可能大地降低运营商惩罚为目标,通过动态切片调整和迁移策略将虚拟网络功能(VNF)和虚拟链路迁移到满足资源限制的物理节点和链路上。仿真结果表明,所提算法有效提高了切片迁移的效率和网络资源利用率。     

一种基于深度增强学习的智能路由技术

随着网络规模的不断增大以及网络复杂度的不断提高,传统路由算法面对网络流量在时空分布上的剧烈波动难以兼顾计算复杂度和算法效率.近年来,随着软件定义网络和人工智能技术的兴起,基于机器学习的自动路由策略生成逐渐受到关注.本文提出一种基于深度增强学习的智能路由技术SmartPath,通过动态收集网络状态,使用深度增强学习自动生成路由策略,从而保证路由策略能够动态适应网络流量变化.实验结果表明,本文所提出的方案能够不依赖人工流量建模动态更新网络路由,在测试环境下比当前最优方案减少至少10%的平均端到端传输时延.     

基于蚁群算法的通信网络流量分析

常规的通信网络流量分析方法主要利用时间序列获取通信网络流量特征,受不断产生的冗余数据影响,导致其分析的通信网络流量值与实际值差距过大。因此需要基于蚁群算法设计一种全新的通信网络流量分析方法。以通信网络的捕获机制入手,利用数据链路接口及数据包过滤器有效地布设了网络流量测量采集点,输出采集数据,再结合蚁群算法生成网络流量分析模型,获取网络流量跟踪算法,从而完成通信网络流量分析。实验结果表明,在不同验证集下本文设计的通信网络流量分析方法分析的通信网络流量值与实际差值较小,证明设计的通信网络流量分析方法的分析效果较好,具有准确性,有一定的应用价值,可以作为后续通信网络流量预测的参考。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.