无线传感器网络的动态电压调节算法研究

对于能量有限的无线传感器网络,研究如何高效地利用有限能量具有重要意义.根据无线传感器网络多跳路由和拓扑易变的特点,提出一种基于任务驱动的含反馈的动态电压调节算法FB-DVS.该算法根据节点的任务集实时地调节节点的工作电压和频率,并通过反馈环节来修正误差,在保证任务实时性的前提下降低节点能耗.通过对仿真结果分析表明,改进的算法能有效地减少节点的能量消耗,延长无线传感器网络的生命周期.     

无线传感器网络关键节能技术及节能策略研究

无线传感器网络（WSN,Wireless Sensor Network）是一种由传感器、数据处理单元和通信模块集成的微小节点通过自组织方式构成的网络,其节点通常采用无法替换的电池供电,有限的能量使得节能问题成为无线传感器网络的研究重点方向。本文介绍了传感器的能耗情况,结合已有研究重点分析了关键节能技术及节能策略,并指出了研究方向。     

无线传感器网络关键节能技术及节能策略研究

无线传感器网络(WSN,Wireless Sensor Network)是一种由传感器、数据处理单元和通信模块集成的微小节点通过自组织方式构成的网络,其节点通常采用无法替换的电池供电,有限的能量使得节能问题成为无线传感器网络的研究重点方向.本文介绍了传感器的能耗情况,结合已有研究重点分析了关键节能技术及节能策略,并指出了研究方向.     

无线传感器网络的能效分析

能量效率是衡量无线传感器网络性能最重要的指标,介绍了无线传感器网络节点结构,分析了无线传感器节点的主要能耗源.讨论动态能量管理和动态电压调整等提高传感节点能效的技术,从物理层、链路层、网络层、传输层等层次论述了无线传感器网络拓扑所采用的能效机制,最后对功率控制技术进行了分析.     

基于MSP430的无线传感器节点动态功率管理研究

针对无线传感器网络节点低功耗设计问题,介绍无线传感器节点组成及其能耗,分析动态功率管理原理及其算法,研究混合自动控制并对其进行改进。改进的混合自动控制算法通过对环境变量的变化值划分来控制无线收发模块的收发频率,能减少收发次数,降低系统功耗。最后介绍了在MSP430,nRF905和SCA3000组成的无线加速度传感器系统中对倾斜角测量时改进的混合自动控制算法的应用。     

一种节能无线传感器网络

针对无线传感器网络节点能量受限制问题,提出一种节能网络,把监测环境中通电电缆的磁能转化为电能,实现节点能量的自给。采集的能量采用双边调谐阻抗网络传输,通过设计原副边回路参数,令其回路发生谐振来降低自身损耗;组网模式上,用节能静态网络模型代替能耗大的动态组网方式,结合需要,通过切换节点的工作方式来降低能耗。实验证明,能量采集模块一个工作周期采集的能量为10.93 mJ,能够满足传感网络节点工作周期的最大能耗4.68 mJ,验证了节能传感网络可以实现能量自給。     

传感器网络的任务双效节能调度研究

能源供应有限性是局限传感器网络的性能和存活寿命的重要因素,本文从传感器网络节点的任务调度出发,提出动态能量管理DPM和动态电压/频率调节DV/FS的双效处理器节能调度算法,即DV/FS-RM和DV/FS-EDF调度算法;在DPM动态控制空闲任务进入休眠的同时,在保证节点的实时性的前提下,通过DV/FS-RM或DV/FS-EDF算法降低处理器频率,达到更好的节能效果.实验显示,该节能任务调度算法使以电池为能源的传感器网络节点的生存期成倍地延长.     

无线传感器网络能耗分析与策略研究

无线传感器网络技术得到了广泛应用,但是该技术一直受能量的制约,因此能量始终是无线传感器网络的核心问题。通过对传感器节点结构与网络体系的分析,得出了传感器网络的能耗特性。为了延长无线传感器网络的生命周期,对传感器节点工作能耗与传感网络能耗做了具体研究,再从低功耗节点设计、网络协议及环境中能量补给三个方面总结出了一套有效的节能策略。     

基于半径可调的三维无线传感器网络覆盖控制

针对三维空间下的无线传感器网络覆盖问题,考虑在满足最优覆盖节点集的基础上,同时减少网络能耗,提出了一种半径可调的三维无线传感器网络的低能耗覆盖方法。根据节点具有可调节传感半径的属性,在三维空间中利用遗传算法动态优化节点布局。仿真结果表明,节点的部署能够在达到较高的覆盖率和节点休眠率的同时,有效降低网络能耗,从而延长网络的生存时间。     

基于全网休眠的ZigBee网络节能算法

无线传感器网络节点一般由电池供电而且部署后需要长时间工作,这就导致节点的能量成为网络运行的瓶颈。针对无线传感器网络节点能量受限的问题,提出了一种基于全网休眠的节能新算法。该算法使终端节点、路由节点和汇聚节点都能得到休眠,从而为网络中每一种节点节约能量;同时,为路由节点设计了长、短两种休眠策略,在不影响数据收发的前提下减少能耗。基于CC2630芯片的实验结果表明:与现有相关算法相比,该新算法使节点能耗降低10%。     

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