一种无线传感器网络的能耗平衡覆盖模型

针对无线传感器网络节点能量有限、最小覆盖方法能耗不均衡的问题,该文提出了一种能耗平衡的连通覆盖模型,并对模型进行了分析与仿真。模型利用Voronoi划分和Delaunay三角剖分对传感器网络进行分割,判别重复覆盖目标区域的冗余传感器节点,采用节点到sink点的跳数对节点分层,进而提出选择休眠节点的方法。仿真结果表明,由模型建立的非最小连通覆盖集所导出的无线传感器网络,能够平衡节点能耗、使用优化路由、减弱路由关键点的影响。     

传感器性能对无线网络功耗影响的研究

对无线传感器网络的构成节点进行研究,节点必须适合实际的需求,应尽可能的小、功耗低,并配置合适的传感器、计算机、存储器和通讯工具等。分析了传感器的性能对传感器节点自身的功耗影响,以及对网络总功耗的影响。通过仿真实验研究了传感器的感知半径、反应时间和节点的功耗等性能对传感器网络能耗的不同影响,同时还会影响到网络中观测器接收到的数据信息量。有助于在设计无线传感器网络时,延长网络的使用寿命。     

基于动态半径的事件驱动型无线传感器网络分簇融合算法

事件驱动型无线传感器网络应用于突发事件监测,针对传统网络未考虑事件分布情况及成簇大小等问题,提出一种新的基于动态半径的分簇融合算法。综合考虑事件发生的严重程度及节点性能等因素确定簇头,并采用分级发射功率,根据成簇效果及网络平均能耗优化选择簇半径,实现在触发节点范围内的动态分簇,有效节约能耗、提高数据融合效率。仿真实验结果表明,与TEEN相比,该算法可显著延长无线传感器网络生命期。     

基于辅助圆覆盖盲区的WSN节点调度算法

文章设计了一种无线传感器冗余节点判定机制(ARCBA,Auxiliary round cover blind area),通过判定高度密集的随机部署无线传感器网络中的冗余节点,在保证覆盖率不变的前提下,通过减少活跃节点数,降低传感器网络的通信能耗。并通过仿真验证,ARCB算法在保证网络完全覆盖的前提下,能有效的延长网络的生命周期,减少节点的能量消耗。     

基于混合机制算法的WSN节能优化策略

在WSN(无线传感器网络)节能优化过程中,覆盖模型复杂、抽象难以求解.部分节点利用率与覆盖率存在差异性,从而制约无线传感器网络,使能耗降低.针对此问题,提出一种基于混合机制的算法,利用分治思想将节点分为活跃节点和非活跃节点;将部分覆盖算法和唤醒机制算法相结合,建立最优覆盖模型,然后进行求解,得到最优节能方案.该方法能够充分利用节点的不同特点降低算法复杂度,避免不必要的运算消耗.实验表明:混合机制算法分别降低了活跃节点与非活跃的节点能耗;与单一算法相比较效果显著,网络生命周期得到延长.     

基于DV-HOP的改进算法WDV-HOP及仿真

无线传感器网络节点的位置信息对于收集信息至关重要。节点定位技术是无线传感器网络中的关键技术之一。文中在分析了传统DV-HOP算法的基础上提出了改进算法WDV-HOP(加权DV-HOP),并对改进的算法进行仿真验证。仿真结果表明,WDV-HOP算法在相同的锚节点数量及覆盖半径下,节点定位精度有3%的提高。另外,WDV-HOP算法还可减少锚节点的数量,降低了网络硬件投资成本。     

无线传感器网络中基于映射扩散的节点定位算法

提出了一种基于映射扩散的无线传感器网络节点定位算法,适用于规模较大、参考节点较少的无线传感器网络.该算法在传感器网络中首先随机选择一个节点作为"起始节点",然后根据扩散算法选择3个"一级节点",然后以每个一级节点为中心,逐级外推,直至覆盖网络中的所有节点.仿真结果证明,该算法可以快速准确进行定位,可降低和均衡所有节点的能耗,提高定位精度.     

基于能量预测的无线传感器网络节点覆盖调度算法

针对无线传感器网络中存在的热区问题,采用非均匀部署方案,并在此基础上提出基于能量预测的无线传感器网络节点覆盖调度算法。并对算法进行了仿真实验和性能分析。结果表明该算法可以延长的网络生命周期并在较长的时间里保持较高的网络覆盖率,能够达到网络内大多数节点能耗均衡的设计目标。     

面向智慧园区的WSN路由优化算法

为解决智慧园区中无线传感器网络(WSN)的能耗不均衡问题,构建了路由代价函数,并提出了一种新的能耗均衡路由算法.该算法结合智慧园区中无线传感器网络的特点,综合考虑节点地理位置和剩余能量来构建路由代价函数.传感器节点通过选择其邻居节点中路由代价最小的节点进行数据转发.仿真结果表明,该算法可以有效节约网络能耗,同时延长了网络的生命周期.     

能耗均衡的无线传感网络不等环分层路由算法

针对无线传感器网络(Wireless Sensor Network,WSN)中邻近汇聚节点(sink)的传感节点负荷和能耗过载问题,基于整体网络能耗平衡目标,提出一种不等环的次优分层网络路由。在均匀分布的传感节点环境中,以sink为中心,按照拓扑距离进行分环多跳路由,理论推导了不等环半径,并考虑单跳能耗。实验分析仿真结果表明,该路由分层模型延长了网络生存周期,提高了节点利用效率,且达到网络内大部分节点能耗均衡的目标。     

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