Ad hoc网络路由协议的节能算法

AODV（Ad hoc on—demand distancevector）路由协议是Ad hoc网络中一种具有代表性的按需路由协议，传统的AODV是以“最小跳数”为参数建立和更新路由的，随着网络负荷的增加，以这种方式建立和更新路由容易引起网络中部分节点较其他节点更多地参与通信，在这些节点发生拥塞的可能性将更大，频率将更高，这会增加网络能耗缩短网络生存时间。针对这一问题，我们提出了一种通过控制拥塞对AODV进行节能改进的算法——Lengthen Lifetime AODV（LLAODV）。     

多跳蜂窝网互连性研究

将Ad Hoc网络与蜂窝网融合首要解决的问题是Ad Hoc如何接入蜂窝网,多数方案使用的是移动IP。提出了一种基于扩展Ad Hoc路由协议的多跳转发网络方案。Ad Hoc多种路由协议中可以实现Ad Hoc网络与蜂窝网互连的只有DSDV,但在移动场景中的低性能限制了它的发展。AODV是Ad Hoc路由协议中最有前途的协议,但它并不支持Ad Hoc节点接入基站的路由搜索。研究对AODV协议进行改进,以使它能支持移动节点到固定基站以及有线网络的寻路。     

移动代理在MANET路由协议中的应用研究

移动Ad Hoc网络(MANET)是由移动节点组成的分布式异构网络,其路由协议的研究是该领域的焦点之一。本文分析了现有移动Ad Hoc网络两类路由协议的优缺点,接着提出将移动代理应用于AODV路山协议的方案,最后给出了初步的仿真结果。仿真结果表明,通过移动代理的漫游更新途经节点路由表,可以在网络负载增加不人的情况下,减少路由发起数,降低端到端的数据传输延迟。     

Ad Hoc网络中一种基于灰色关联算法的路由协议

针对移动Ad Hoc网络中节点任意移动、网络拓扑频繁变化导致以最小跳数作为路由选择机制的AODV路由协议面临频繁连接中断而造成网络QoS下降的问题,文章综合节点的剩余电量、剩余队列长度和源节点到目的节点的跳数三个跨层信息,提出一种基于灰色关联算法的改进AODV路由协议(GRA-AODV)。仿真结果显示:相比于改进前的AODV协议,改进之后的GRA-AODV(Gray Relevance AlgorithmAODV)协议在稍微增加路由开销的情况下,具有更低的平均端到端时延和更低的分组丢失率,在拓扑频繁变化的移动Ad Hoc网络中具有较好的鲁棒性。     

Ad Hoc 网络按需路由协议性能分析

无线移动Ad Hoc网络作为可移动分布式多跳无线网络，没有预先确定的网络拓扑或网络基础设施以及集中控制。为了在这样的网络中促进通信，路由协议主要用于在节点之间发现路径。Ad Hoc网络路由协议的主要目的是网络拓扑的动态变化任意两个节点之间建立一个使得通信总费用和带宽消费最少的正确和有效的通信路径。使用OPNET仿真软件对AODV、DSR协议这两种典型无线移动Ad Hoc网络按需路由协议的参数和性能进行了详细比较和分析。     

基于移动性的AODV路由协议改进

介绍了Ad Hoc网络路由协议（Ad Hoc On-Demand Distance Vector Routing,AODV）的路由机制和特点,提出了一种基于AODV的改进协议V-AODV。V-AODV改进了AODV的路由测度,用量化的节点移动性代替跳数作为路由代价的度量,在动态网络中能够选取到更加稳定的路由。仿真表明,V-AODV比AODV在时延和重传次数等性能上都有一定程度的提升。     

Ad Hoc网络负载均衡路由协议研究

网络负载是影响Ad Hoc网络性能的重要因素,网络负荷比较重时,局部的拥塞将导致网络性能的下降,分析研究现有负载均衡路由协议,并利用链路层信息,结合原Ad Hoc路由协议AODV提出了一种跨层负载均衡的路由协议方案,在选路过程中引入负载均衡机制,均衡网络流量,以提高网络时延、分组到达率等性能.最后用NS2软件仿真证明了改进路由算法的优越性.     

AODV路由协议路由修复研究和改进

Ad Hoc网络具备拓扑的动态性,该特性使得一般路由协议无法正常工作,且网络节点移动变化性,也会提升路由断裂的发生率。AODV路由协议作为Ad Hoc网络目前使用最为频繁的一种路由协议,其重要性和高效率性不言而喻。主要对AODV路由协议的修复研究与改进进行分析和探讨,从AODV协议的工作原理、修复研究以及改进方法等几个方面进行了阐述。     

Ad Hoc网络中一种改进的AODV路由协议

Ad Hoc网络路由协议的设计一直是Ad Hoc网络中的热点问题。本文在AODV协议的基础上,通过为RREQ消息设置时限,将节点的剩余生存周期和负载情况综合考虑,提出了一种改进的AODV协议。仿真结果表明,改进后的协议提高了分组交换率,降低了网络开销,从而延长了网络生存时间并且提高了网络性能。     

一种基于距离矢量的Ad Hoc网络拥塞适应路由协议

DSDV是一种基于距离矢量的Ad Hoc网络路由协议,该路由协议在网络负载较大的情况下,网络性能下降很快。本文对DSDV协议进行了改进,使之能实现拥塞感知和拥塞适应功能,提出了一种拥塞警告距离向量（congestion-aware distance vector, CADV）协议。基于NS-2的仿真结果显示,相比于DSDV和AODV,CADV在网络吞吐量和平均分组投递延时方面的性能有了明显的提高,受到节点移动速度变化的影响是最小的。     

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