一种时滞网络自适应主动队列管理算法研究

主动队列管理(AQM)算法的自适应能力和克服滞后性不良影响的能力是该文研究的重点。在分析AQM采用传统PID存在的问题的基础上,提出了一种时滞网络的自适应主动队列管理(FAGPID)算法。由模糊控制器实现PID参数对动态网络环境的在线自适应调整;成功引入灰预测算法实现反馈数据的超前预测,补偿滞后。仿真对比AQM环境中FAGPID,传统PID以及基于模糊免疫PID(FIGPID)的算法,可知FAGPID相对于FIGPID复杂度低,但FAGPID与FIGPID性能相当,均能克服滞后的影响,能快速稳定地适应动态网络环境,收敛于期望队列长度,具有较小的丢包率,优于传统PID算法。     

基于动态输出反馈控制的主动队列管理算法

 针对网络拥塞控制的不确定时滞特性,提出了一种基于动态输出反馈控制(DOFC)的主动队列管理(AQM)算法.建立了TCP/AQM系统的时滞有界模型,给出了判定闭环AQM系统稳定的充分性条件,以及基于线性矩阵不等式的动态输出反馈控制器参数设计方法.仿真结果表明,该算法在大时滞的网络环境中,能迅速地将队列长度收敛到目标长度附近,且在特征参数变化的网络环境中具有较强的鲁棒性.     

一种基于模糊逻辑的主动队伍管理算法

主动队列管理（AciiveQueue Management,AQM)技术作为Internet拥塞控制的一种有效方法，对于提高Internet的服务质量具有十分重要的作用，本文根据TCP拥塞控制算法基于数据包丢失的窗口变化机制，设计了一种基于模糊逻辑的主动队伍管理算法，该算法依据路由器中队列长度的变化情况，根据一定的模糊自校正原则来调整数据包的丢弃概率，从而使路由器中的队列长度稳定在参考值附近，仿真结果表明该算法不但十分有效，而且对不同的网络状况具有很好的适应能力。     

基于模糊神经网络的拥塞控制算法研究

本文介绍一种基于模糊神经网络的主动队列管理(AQM)算法,实现网络拥塞控制。利用神经网络来实现模糊推理,可自适应修正隶属函数的参数和加权系数,优化模糊逻辑控制器,从而达到某种性能指标的最优化。仿真结果表明,采用模糊神经网络进行流量速率预测的拥塞控制策略能够使缓冲器队列长度快速收敛到目标值,并且维持小的队列震荡。结果也表明该方法与传统的PD控制器相比具有更好的性能和鲁棒性。     

一种基于模糊逻辑的主动队列管理算法

主动队列管理 (ActiveQueueManagement,AQM)技术作为Internet拥塞控制的一种有效方法 ,对于提高In ternet的服务质量具有十分重要的作用 .本文根据TCP拥塞控制算法基于数据包丢失的窗口变化机制 ,设计了一种基于模糊逻辑的主动队列管理算法 .该算法依据路由器中队列长度的变化情况 ,根据一定的模糊自校正原则来调整数据包的丢弃概率 ,从而使路由器中的队列长度稳定在参考值附近 .仿真结果表明该算法不但十分有效 ,而且对不同的网络状况具有很好的适应能力 .     

大时滞网络拥塞控制器的设计

几乎现有的AQM算法都忽略了大时滞对网络拥塞控制系统稳定性的负面影响,以致稳定性、响应性和鲁棒性在大时滞网络中大大降低.如PI、REM等AQM算法在大时滞环境下表现出剧烈的队列震荡和频繁的空队列情况,这些现象直接导致了链路利用率的低下和延时抖动的增大.而面向大时滞网络拥塞控制的DC-AQM算法不够恰当的参数配置使得系统输出偏离了控制的目标,出现了很高的分组丢弃概率.为解决大时滞网络拥塞控制的稳定性问题,本文基于内模控制原理,提出一种新的鲁棒AQM控制器IMC-PID来补偿网络时滞对系统稳定性的影响.仿真分析表明,随着网络时滞的增大,IMC-PID在综合性能上胜过其他算法,获得了较高的链路利用率和较低的延时抖动.     

一种顽健的自校正主动队列管理机制

现有基于控制理论的主动队列管理机制（AQM）大多数是根据简化的线性被控对象模型设计的,或者根据特定的网络条件设置算法的参数,当网络条件大范围变化时算法的性能难以保证.为了解决这些问题,提出了一种自校正的主动队列管理机制STR,通过在线估计TCP/AQM闭环系统被控对象模型的参数,并相应地调节报文丢弃概率,使路由器的缓冲区队列长度与期望值之间的方差最小.通过仿真实验验证了当网络条件大范围变化时算法的队列长度、链路利用率、报文丢弃率等性能,实验结果表明该算法具有良好的顽健性.     

SABlue:一种带加速因子的自适应AQM算法

该文在分析SBlue算法的基础上,提出了一种带加速因子的自适应AQM算法SABlue(Self-tune Accelerate Blue)。算法将瞬时队长作为早期拥塞检测参量,根据队列负载因子控制丢包步长,实现丢包概率幅度的自适应调整,最终将路由队列长度稳定在目标区域内。为了提高网络突变跨度较大情况时算法的响应速度,在队列警戒区域内引入了加速因子。实验表明,SABlue面对突变流和不同RTT的网络场景,队列收敛时间短,丢包率小,且具有较好的鲁棒性,算法综合性能优于其他AQM算法。     

有线网络PSO-PID主动队列管理算法稳定性分析

主动队列管理算法的稳定性是实现拥塞控制的基础,针对目前PID-AQM控制器控制参数大多基于经验、缺乏稳定性分析的问题,提出了粒子群优化PID参数的整定策略,同时运用稳定分析论分析PSO-PID队列管理算法的稳定性.考虑TCP/AQM系统的时滞性,将时延系统利用泰勒展开转化为非时延系统进行稳定性判定.通过NS2仿真,结果表明,PSO-PID算法稳定性明显优于PID算法.     

基于模糊免疫PID的多媒体流自调整算法研究

提出了一种基于模糊免疫PID的多媒体流自调整算法(MFIPID),实现对多媒体流的在线自调节和多媒体流资源有效管理。分析多媒体流自适应节模型,实现IP网络可用带宽的预估计,采用全论域范围内带有自调整因子的模糊规则自调整方法进行免疫抑制量的模糊非线性逼近,并与免疫反馈机理相结合,多媒体流传输过程中自适应整定PID参数以改进传统PID算法。仿真验证了MFIPID算法的有效性。     

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.     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks