云数据中心时延优化的数据放置方法

针对云数据中心数据获取效率低和服务器资源浪费问题,为优化云平台的数据访问和资源利用,文中提出了一种时延优化的云数据中心数据放置（LOP）方法。文中首先分析了云平台的性能,建立了云平台的资源利用和数据获取时间模型。然后基于非支配排序算法NSGA-Ⅲ实现了全局最优的数据放置策略,对数据资源进行合理部署,有效利用服务器的资源,提高了数据获取的效率。最后通过CloudSim仿真平台,对提出的数据放置方法进行了仿真和对比实验。实验结果表明,LOP方法能明显提高云服务器的资源利用率,缩短任务的数据获取时间。     

基于云环境下的负载均衡算法研究

针对传统遗传算法易陷入局部解等缺点,提出了一种改进的元胞遗传算法,并将其运用到云环境下的负载均衡中.在云环境中,由于用户任务请求量大,会出现有些服务器过载,而有些服务器闲散的问题,利用该算法找到能提高服务器利用率的方法.在Clousim3.0仿真平台上进行试验,结果表明,该算法能提高服务器利用率,缩短任务完成时间.     

车联网场景下移动边缘计算协作式资源分配策略

为了有效利用边缘云的计算资源,尽可能降低任务卸载时的平均等待时延,提出了一种满足边缘计算服务器容限阈值和任务卸载成功率约束条件下的多个边缘计算服务器相互协作的资源分配方案,通过单位时间总代价指标优化边缘计算服务器个数.将此方案建模为一个整数优化问题,之后设计了一种最小代价算法求解此优化问题,得到约束条件下的单位时间总代价以及任务平均等待时延.仿真结果表明,与已有方案相比,所提方案降低了单位时间总代价和任务卸载平均等待时延.     

基于指纹魔方算法的云存储数据保护机制

云存储有效解决了存储性能瓶颈,同时带来了数据安全和隐私保护难题.为了解决这一问题,提出了一种基于指纹魔方算法的云存储数据保护机制.该机制通过用户的指纹特征值控制魔方旋转对文件进行加密,再利用门限分割技术将文件分割成小块存储到各个服务器中.需要恢复原文件时,先对各个服务器中的文件块进行完整性验证,找到不少于门限值数量的文件块就能完整恢复文件.该机制保护了云存储用户的隐私数据,同时提高了云存储系统的抗破坏能力和灵活性.     

一种基于小波阈值理论的遥感图像复原新算法

通过分析云部分覆盖的单幅遥感图像,并经过多层小波变换后,得到景物信息和云噪声在小波分解系数中的分布关系,提出能有效去除云噪声的云区阈值法.实验证明,该算法的去云效果远优于同态滤波和Retinex算法,且能充分保留云区以外景物信息.     

基于内容的分布式web服务器负载平衡算法

通过分析服务器对静态内容和动态内容处理过程的不同,在给出分布式网络服务器系统结构模型的基础上,提出了一个新的将静、动态内容分配都考虑在内的周期更新动态负载分配算法;通过将其加载在所建立的仿真平台上进行测试得到的最终结果可以看出,所给的负载平衡算法能有效的使系统达到并且保持负载平衡.     

基于云模型的文本数字水印算法研究与实现

提出了基于云模型的文本水印算法.利用云模型的随机性和模糊性,设定云模型的参数作为密钥,通过正向云发生器产生水印信息,水印映射到坐标轴上形成一幅云图.采用小波域自适应量化的方法,根据嵌入位置的不同选取不同的量化系数,将水印嵌入到载体文本中.提取后既可以对云进行视觉上的判断,又能通过逆向云发生器得到云模型的参数,并且给出了定量判断的方法.实验结果表明:基于云模型的文本水印算法比传统水印具有更高的鲁棒性和不可感知性,可有效保护文本作品的版权.     

一种基于HSFC的云资源定位算法

针对云计算环境下,云资源的模糊查询问题,提出了一种云资源定位算法。该算法建立在双层Chord环模型上,同时结合Hilbert空间填充曲线(HSFC),实现多维属性的降维,进而完成云资源的定位。另外,该算法将整个资源空间划分成多个资源区间,并提出邻居区间的概念,通过邻居区间,可较好地实现云资源的模糊查询,此外该算法还为每个属性设置属性权值,以此减少网络请求数量。实验表明,该算法不但能有效解决云资源的模糊查询,且能降低查询时延,提高查询效率。     

构建云资源全生命周期运营管理，助力企业级云精细化运营

随着云计算、大数据等技术的普遍使用,业务上云已经成为主流趋势,云服务商业似雨后春笋般出现。云资源的规模也越来越大,动辄几万甚至几十万台服务器的规模;云上承载的业务系统数量迅速增至几百甚至几千,运营分析的维度也变得精细化、多样化,传统粗犷的云资源运营管理方式已无法满足日益增长的运营分析需求。一套有效的云资源全生命周期精细化管理运营体系,能为云用户提供便捷得云资源服务,也能充分发挥“云”的优势,实现云资源的可控、可管、可查,助力云服务商、云用户实现降本增效。     

基于离散小波框架变换的遥感影像薄云去除

遥感影像可见光波段受云层变化影响较大,如何有效去除云的影响是遥感图像处理中的一个重要问题.本文提出了一种基于离散小波框架变换的薄云去除算法.在小波框架变换多尺度分析的基础上,算法在低频图像上将云区和清晰区区分出来,并进行均值匹配.然后对于小波高频系数在不同尺度上进行不同程度的增强;对同一尺度的系数进行非线性处理以增加对比度,最后通过反变换得到去云后的图像.实验表明,该算法能有效地去除薄云,增强图像对比度,减小噪声的增强幅度,使结果图像具有很好的视觉效果.     

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