基于分簇P2P的多跳无线mesh网络资源检索与分发算法

针对多跳无线mesh网络中拓扑结构和不同类型节点的特征,将多跳无线mesh网络建模成分簇P2P结构.为了降低资源发布的开销,在进行资源共享设计时,利用布鲁姆过滤器作为资源表示和消息在网络中传输.以布鲁姆过滤器为基础,提出了一种基于资源密度敏感的多跳无线 mesh 网络资源检索和分发算法,将移动客户端的资源下载请求转发到拥有资源副本最多的P2P分簇,利用该分簇的多个资源副本备份提供资源下载服务,最大化降低节点移动性产生的资源下载中断.仿真结果表明所提出的资源检索和分发算法能有效提升资源的下载性能.     

一种新的基于最大流的无线Mesh网络信道分配算法

在无线Mesh网络中,为节点配置多接口多信道MAC协议成为提高网络性能、扩大网络容量的有效手段之一。有效的信道分配策略在多信道无线Mesh网络中显得尤为重要。本文提出一种基于最大流的信道分配算法。该算法通过最大流计算网络中可达到的最大吞吐量,以此作为网络负载标准进行信道分配,将降低整个网络的总体干扰作为目标函数进行优化。仿真结果表明,即使在网络负载较重的情况下,算法仍能保持较好的性能。     

基于贪心算法的无线mesh时空域多信道分配研究

无线mesh网络多接口多信道分配算法中,信道分配与接口数目之间存在相互制约、相互依赖、“涟漪效应”,导致链路无效以及承载网络拓扑的主要业务节点存在时序关系,本文在基于多信道空间和时间联合信道分配算法的基础之上,考虑前一个子时序已分配信道对下一个子时序信道分配的影响,提出了基于贪心算法的无线mesh时空域多信道分配算法.根据贪心算法原理,尽量不改变已分配信道,减少信道切换时间,将剩余的未分配信道分配给要分配的接口,使信道能并行工作以提高整个网络的吞吐量.通过实验仿真,对比了能够抑制“涟漪效应”和链路无效的静态多接口多信道分配算法、空间与时间相结合的多接口多信道分配算法.结果表明,整个mesh网络的吞吐量有明显提高,且随着网络中业务节点变化的减小而增大,随着可利用信道数目的增加而增加.     

无线mesh网络中的信道分配问题研究

在多接口无线mesh网络中使用多信道可以减少碰撞和干扰,提高系统吞吐量。因此,合理的信道分配是无线mesh网络中多信道技术的关键。用图论理论建立信道分配数学模型以及用图着色理论研究信道分配问题是无线网络中解决信道分配问题的有效方法。因此针对无线mesh网络中多接口多信道(multi-radio and multi-channel)的特点,重点介绍了无线mesh网络中信道分配的基本理论、主要约束和图论模型等,最后提出应用图着色理论解决信道分配问题的一般途径。     

无线mesh网络中可信协同信道资源分配策略

为了有效提升无线mesh网络信道资源的利用率和网络服务质量,提出基于可信协同的信道资源分配策略.针对节点自适应特点,引入博弈理论、建立节点的信誉机制以实现节点可信协同并优化信道分配结果.仿真实验分别对节点服务等级、网络收益结果作相应评价.实验结果发现节点服务等级对节点网络收益有直接影响,当协同服务等级达到3时,网络收益状况最佳,此时节点跳数与服务等级呈协同关系;对比经典协同算法,在相同网络拓扑环境下,可信协同信道资源分配策略分别是UACRR算法、DMP-MBA算法的1.04倍、1.069倍,明显占优.     

基于交叉层设计的MIMO Ad—hoc网络的MAC层调度算法

在应用多入多出(MIMO)技术的无线Ad-hoc网络中,基于交叉层优化,设计了介质访问控制(MAC)层的优化调度算法。通过网络层、MAC层及物理层交换关键参数信息,在各无线节点分布式地进行优化调度,以选择发送节点以及在这些节点上进行流分配,选择用于发送数据的天线阵列子集,从而提高整体网络的性能。仿真结果显示,与简单单链路算法相比,交叉层设计优化算法可以显著提高MIMOAd-hoc网络的整体容量。     

信道估计对无线分组调度算法公平性的影响及改进

无线分组调度算法是无线mesh网络中QoS技术的关键。TIMELY无线网络分组调度算法模型中,信道的状态被简单定义为好与坏两个状态。文章针对无线mesh网络中信道状态时变的特点,主要研究无差错服务和信道估计部分,将信道状态量化为若干阶进行讨论,改善无线分组调度算法的公平性。通过分类调度和8状态马尔可夫链（Markov Chain）信道状态转换,可以有效提高系统吞吐量、降低平均分组时延。     

一种基于博弈论的无线mesh网络信道分配算法

无线mesh网络中的信道分配会极大地影响网络的性能。为了解决无线mesh网络中的信道分配问题,提出了一种基于博弈论的信道分配(GBCA)算法。该算法将网络中每一个节点模型化为一个博弈者,每个博弈者的策略为信道的分配方案,并将整个网络的吞吐量作为效用函数的目标,效用函数的物理意义则是在给定流量需求矩阵下传输的成功率。博弈者通过相互博弈来优化收益函数,以最大化网络吞吐量。并针对GBCA算法的不足,提出了一种改进算法———GBCA-TP算法。通过NS2.34仿真分析得出,GBCA算法和GBCA-TP算法在收敛性、分组丢失率和吞吐量上都要优于当前的算法。     

增强型的无线Mesh网络信道分配方法

为更可靠地实行无线mesh网络的资源分配,将干扰模型引入mesh网络的节点流量模型中,提出改进型的基于流量感知的固定C-HYA信道分配方法,采用一种更贪婪的算法规避波纹效应,降低网络干扰。之后对算法进行实现仿真,建立相应网络拓扑结构,对在mesh网络中采用传统算法及改进算法对抗波纹效应及信道干扰的情况进行了对比分析。     

基于协作MIMO和睡眠机制的中断概率性能研究

利用无线传感器节点间的相互协作形成协作MIMO系统可有效对抗无线信道衰落。基于Nakagami信道,该文研究协作MIMO系统的中断概率。首先建立节点睡眠机制和总功率受限情况下,综合考虑节点传输能耗和处理能耗,系统中断概率最小的优化模型。接着,讨论了优化模型的理论解。最后,通过仿真来验证算法的有效性。      

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.     

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.     

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.     

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.     

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.     

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.     

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