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.     

能量采集型无线传感器网络的高能效路由算法

在能量采集型无线传感器网络中,虽然有能量吸收,但是因能量依然非常珍贵,如何优化路由协议,提高能量利用率,延长网络寿命仍然是值得研究的问题.为求解高能效的路由,提出了一种采用遗传算法的高能效路由算法,建立考虑节点的吸收能量、剩余能量、消耗能量和浪费能量的适应函数,用遗传算法寻找全局最优路径.将该适应函数与3种其他适应函数作对比,其他3种适应函数分别为只考虑路径能耗最小的适应函数,考虑路径能耗与路径上节点的吸收能量、剩余能量的适应函数以及考虑路径能耗与网络中所有节点的浪费能量的适应函数.采用遗传算法解出4种路由,通过仿真分析可知,所提出的路由算法能量利用效率最高.     

基于网络编码的多播路由算法性能分析

多播传输是目前通信系统中的一项关键技术,可以将相同的信息同时传向多个接收节点。该文提出一种基于网络编码的新的多播路由算法,该算法利用Dijkstra约简网络搜索源节点到各接收节点的路径族。仿真结果表明,该算法在资源消耗和负载均衡方面较传统的多播路由算法有更好的表现,同时性能也更接近基于网络编码的最小费用多播算法。最后,数学分析表明该算法具有较低的计算复杂度。     

基于改进PSO的铁路监测线性无线传感器网络路由算法

为了解决铁路监测场景中线性无线传感器网络的节点间能耗不均衡导致的网络生命周期短、数据传输时延大的问题,提出了一种基于粒子群优化理论和广度优先搜索的路由算法。以候选簇头节点的相对能耗、簇头间距和簇头负载为指标构建适应度函数,通过调整惯性权重系数增强粒子群算法局部搜索能力,获得簇头最优解集;构建能耗与时延驱动的路径成本函数,基于广度优先搜索获得源节点到sink节点的最优主路径;设计基于Markov决策过程（MDP）模型的Q-learning备选路径更新与路由维护机制。仿真结果表明,所提算法能够有效均衡节点间能耗,在延长网络生命周期和降低数据传输时延方面具有较优的性能。     

一种基于蚁群算法的WSN能效均衡路由

为了解决无线传感器网络的能耗不均衡问题,提出了一种基于蚁群算法(ACO)的自适应能量均衡路由算法(EBEA).该算法将节点的能量密度融入到启发因子中,利用蚂蚁的动态适应性在全局范围内寻求最优路径让网络达能量均衡的效果.仿真实验结果表明,与LEACH算法相比,该算法能够均衡整个网络的能耗,并有效的避免了网络分割或者"能量空洞"现象,延长网络的生命周期.     

无线传感器网络中能耗均衡的数据收集算法

无线传感器网络所具有的集中式数据收集、多跳数据传输、多对一流量模式容易导致严重的包碰撞、网络拥塞,包丢失,同样也会导致能量消耗的热点出现,使某些节点甚至整个网络过早死亡.文中提出一种能耗均衡的数据收集算法,此算法按节点离基站的距离进行分层,根据中间节点的能量参数和通信开销建立到基站的多径路由,在数据收集过程中除了利用具有最小能耗的最优路径外还偶尔使用一些次优路径;为进一步减少节点能耗,算法还采用了数据聚合机制.分析和仿真结果表明,算法在很大程度上均衡了节点间能耗并延长了网络寿命.     

无线传感器网络能量均衡路由博弈算法

针对无线传感器网络节点能耗不均匀,容易形成网络分区的问题,提出了一种基于博弈论的无线传感网络路由选择策略,建立传感器节点之间以剩余能量为效用的博弈模型,求解并确定节点剩余能量最优的路由。仿真结果表明,所提出的路由选择策略可以有效地最大化节点的剩余能量,同时当该模型处于纳什均衡解时,每条路径的能耗处于均衡状态,有效地利用了传感器节点的能量资源,避免了网络能量的空洞,延长了网络的生命周期。     

无线传感器网络动态分簇路由BWAS的算法研究

为加快无线传感器网络(WSN)路径搜索速度,减少了路径寻优能量消耗,提出了基于最优-最差蚂蚁系统(BWAS)算法的无线传感器网络动态分簇路由算法。该算法是基于WSN动态分簇能量管理模式,在簇头节点间运用BWAS算法搜寻从簇头节点到汇聚节点的多跳最优路径,以多跳接力方式将数据发送至汇聚节点。BWAS算法在路径搜寻过程中评价出最优-最差蚂蚁,引入奖惩机制,加强搜寻过程的指导性。结合动态分簇能量管理,避免网络连续过度使用某个节点,均衡了网络节点能量消耗。通过与基于蚁群算法(ACS)路由算法仿真比较,本算法减缓了网络节点的能量消耗,延长了网络寿命,在相同时间里具有较少的死亡节点,具有较强的鲁棒性。     

基于TinyOS的无线传感器网络LEACH算法的改进

LEACH协议是无线传感器网络中最流行的分簇路由协议之一.针对LEACH算法簇分布不均匀以及网络能耗不均衡等问题提出了一种高效节能多跳路由算法.在簇建立阶段,新算法根据网络模型计算出最优簇头间距值,调整节点通信半径以控制簇的大小,形成合理网络拓扑结构;在数据传输阶段,簇头与基站之间采用多跳的通信方式,降低了节点能耗.在TinyOS操作系统下,使用nesC语言设计实现了LEACH-EEMH算法.基于TOSSIM平台的仿真结果表明,新算法较LEACH算法在均衡网络能耗、延长网络寿命方面具有显著优势.     

基于仿人体血管路径WSN故障容错路由算法研究

为提高无线传感器网络(WSN)故障容错性和传输稳定性,实现网络负载均衡,提出了一种仿人体血管路径的WSN故障容错路由算法.通过研究人体血管路径特性,将其引入到WSN故障容错路由设计中,在对网络节点分区域进行等级标定的基础上实行能耗均衡的静态分簇;运用改进的蚁群算法生成节点路径并计算各路径信息素值,以确定传输路径选择概率并建立仿血管拓扑结构路由.理论与仿真结果表明,此算法具有良好的性能.     

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