云计算：从概念到平台

云计算是以虚拟化技术为基础,以网络为载体提供基础架构、平台、软件等服务为形式,整合大规模可扩展的计算、存储、数据、应用等分布式计算资源进行协同工作的超级计算模式。作为一种全新的互联网应用模式,云计算将成为未来人们获取服务和信息的主导方式。针对当前云计算概念混杂的现状,提出了一个较综合的参考性定义,并分析了云计算与分布式计算、网格计算、并行计算、效用计算等相关计算形式的联系与区别。对目前主流的云计算平台实例进行了概括性介绍。从云平台的层次更深刻地剖析云计算的本质。     

云计算环境下的安全应用

云计算是一种新兴的应用模式,他将传统的应用计算资源整合形成容量更大、速度更快的云服务中心。云计算是以虚拟化技术为基础,以网络为载体,提供基础架构(IaaS)、平台(PaaS)、软件(SaaS)等服务,整合大规模可扩展的计算、存储、数据、应用等分布式计算资源进行协同工作的超级计算模式。云计算的应用能够扩展     

Hadoop云平台下的并行化图像处理实现

近年来,云计算在IT行业掀起了新一轮技术革新浪潮。云计算是一种新兴的计算模型,它是并行计算、分布式计算、网格计算的综合发展,以简单、透明服务的形式提供无限制的计算资源。Hadoop实现的开源云平台提供了并行计算模型MapReduce、分布式文件系统HDFS和分布式数据库HBase等。随着数字图像数据量不断增长,单机模式的图像处理已逐渐不能满足用户需求。文中提出了利用Hadoop云平台实现海量图像的并行     

关于云计算服务监管问题的思考

1引言所谓云计算是一种通过网络统一组织和灵活调用各种ICT信息资源,实现大规模计算的信息处理方式。云计算利用分布式计算和虚拟资源管理等技术,通过网络将分散的ICT资源(包括计算与存储、应用运行平台、软件等)集中起来形成共享的资源池,并以动态按需和可度量的方式向用户提供服务。云计算服务以其便捷、按需、弹性的创新服务模式很快成为业内关注的焦点,企业、各地政府纷纷进行规划部署,推出以云计算服务为核心的发展战略,推动国内云计算产业呈加速发展的势头。     

基于Eucalyptus构建私有云计算平台

随着云计算的发展与深入,公有云在网站数据处理、在线服务等领域作用显著。与公有云相对,私有云计算凭借其安全性保障、高效个性化的弹性计算资源分配能力、简易的硬件要求等特性,逐渐在科研实验室、工作站、企业内部等小型分布式计算环境中得到广泛应用。本文基于Eucalyptus开源云计算平台,构建了一个适用于科研实验室及企业内部使用的私有云计算平台,既能弹性分配计算资源,满足开发、测试、管理等不同需求,又能为集群技术、分布式计算、云计算应用等研发工作提供实用平台。本文通过虚拟实例的仿真实验,验证了私有云计算平台在计算资源同构化时的优良性能。     

基于云计算的工业互联网数据资源管理平台构建

云计算作为一种新兴的商业计算模型,融合了分布式计算、并行计算、效用计算等计算机技术与网络技术的优势,为互联网络提供了一个安全、可靠的运行环境。为推进工业互联网平台的自动化、智能化、数字化、网络化发展,技术人员将云计算技术与工业互联网数据资源管理平台的构建工作融为一体,旨在发挥云计算模式低成本、高效率与高可用性的应用优势,以增强工业互联网平台的安全性、可靠性与稳定性。基于此,文中着重围绕基于云计算的工业互联网数据资源管理平台的构建思路展开了论述,以此来强调云计算技术在平台构建过程中的重要作用。     

云计算（3）

通过前面两章对云计算的介绍,读者对云计算的基本组成、体系结构、它与其他分布式计算技术等应该有了一个比较深入的了解。这篇文章将介绍云计算的计算模型,了解目前为大众推崇的Google云计算平台上典型的分布计算是如何进行的。接着分析了云计算领域先驱者成功的关键因素,这对有意投入云计算领域的企业能有所借鉴。最后作者从云计算模式、运营模式、以及可靠、安全与隐私等方面讨论了与云计算相关的经济技术问题以及未来云计算的发展趋势。     

面向云计算平台的数据安全问题和保护策略研究

云计算平台涉及商务、经济、交通、零售等众多领域和应用场景。作为一种基于互联网的分布式计算技术,云计算平台以按需方式提供数据资源,可配置网络、服务器、应用程序、存储等计算资源共享池。而在云存储被广泛应用,创造价值的同时,这些数据也成为黑客、APT、病毒攻击的“标靶”,出现数据泄露、账户劫持等问题。文章从云计算所面临的安全威胁、数据安全风险等问题入手,探讨了云计算数据的隐私保护、安全存储管理路径等问题,以期能为云计算服务的安全优化提供有益的参考建议。     

《云计算白皮书》选编 云计算

1云计算概念云计算(Cloud Computing)是一种通过网络统一组织和灵活调用各种ICT信息资源,实现大规模计算的信息处理方式。云计算利用分布式计算和虚拟资源管理等技术,通过网络将分散的ICT资源(包括计算与存储、应用运行平台、软件等)集中起来形成共     

云计算在网络课程中的应用研究

随着大数据时代的到来,网络如何快速和便捷处理如此庞大的数据量,为人们提供更好的服务,成为了当前亟待解决的问题。在这样的大背景下,新的网络计算模型——云计算随之产生和发展。云计算是以用户为中心,进行的分布式计算。本文将首先分析云计算在网络课程中的应用价值,在此基础上基于云计算技术设计网络课程平台,最后,对云计算在网络课程中的应用技术进行分析和探讨,以期能够对网络课程行业的发展有一定的参考价值。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.