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1.
1 Introduction Sinceanorganiclight emittingdiode (OLED)withhighefficiencywasreportedbyTangandVanSlyke[1]in 1987,flatpaneldisplaysbasedonOLEDshavebeendeveloped .Inrecent years ,severallaboratoriesaroundtheworldareengagedindevelopingthemate rials ,devicesandproce…  相似文献   

2.
1 Introduction Computerintegratedmanufacturing (CIM)asaphi losophyhasreceivedworldwideattentionsincethe1980sandhasbeenappliedtodirectenterprisespro ductionsuccessfullyinmanyindustrializedcoun tries[1] .TheUSgovernmenthasconsideredtheman ufacturingindustrytob…  相似文献   

3.
INTRODUCTIONItisafundamentalproblemincomputeraidedgeometricdesign (CAGD)andmanufacturetofindtheintersection (Laneetal.,1 980 ;Wang ,1 984;Sederbergetal.,1 986)oftheparametriccurves.SincemostofthecurvesinCAGDaredenotedbypolynomialsorrationalpolynomials,tofindtheirint…  相似文献   

4.
1 Introduction Sincethe 90’s ,thefemtosecondlasertechniqueshavebeenusedtostudyvariousultra processwithinmaterials,becauseofitshightime resolution .Inchemicalreactions ,chemicalbondbreakingorbondformationisonthescaleoffemtosecond (10 - 15sec ond) [1] .Withfemtosecon…  相似文献   

5.
1 Introduction Overexpansionofindustrieshascauseddegradationofenvironmentalqualityespeciallyinthedevelopedcoun tries.Ozonedepletionhasspurredworldwideenviron mentalcontrol. Forambientatmosphere,theregulatoryauthoritiesinChinademandallindustriestoimpleme…  相似文献   

6.
1  Introduction ShanghaiisthelargestindustrialcityinChina ,anditselectricloadandpowerconsumptiontakeupagreatpercentageofthenationaltotal.Neverthelessthesitua tionhasbeenchanginggreatlyeversincethereform .Ononehand ,theeconomicconditionsandthelivingstandar…  相似文献   

7.
Section1 :BreakdownofForcesYoucanbreakdownforcesintoseveralcomponentseaslily.Forexample,theforceF1 at30degreecanbebro kenintotwoforces:FxandFy,andFx=cos30°×F1 ,Fy=sin30°×F1 .Section2 .TwoDimensionalForcesintoOneYoucancombinetwoforcesintoone.SupposeTompushedaboxwit…  相似文献   

8.
1 Introduction Itiswellknownthatmetalhydridesareanidealmediumforhydrogenstorageduetotheirhighdensityandhigh purityofhydrogen .However ,allknownconventionalmetalhydrides ,includingintermetalliccompoundsAB5,AB2 ,andAB ,havereversiblegravi metricH densitiesnomo…  相似文献   

9.
具有固定成本优势的在位企业的最优许可策略   总被引:1,自引:0,他引:1  
1 Introduction Animportantthemeinindustrialorganizationisthatamonopolistfirmwilluseitsincumbencypositioninordertoinfluencetheentrydecisionsofpotentialcompetitors.Asmallbutgrowingliteratureonthestrategicuseoflicensing[1~ 4 ] hasfocusedontheroleoflicensing…  相似文献   

10.
1IntroductionSincethemid90’s,thefinitediferencetimedomainmethodhasbeenappliedtosolveanumberofacousticalproblems.Examplesin...  相似文献   

11.
INTRODUCTION With the development of novel wireless tech- nologies and increasing available bandwidth, multi- media applications over wireless networks become attractive for both businesses and end users. Fast de- ployment of Wi-Fi HotSpots, increase in wireless coverage of remote habitable areas (Wi-Max, or wireless mesh networks), improved data services over the 2G cellular systems and the long awaited debut of 3G wireless services offer many potential and inter- operable communicatio…  相似文献   

12.
INTRODUCTION Ad-hoc networks are attractive owing to their self-organizing nature and absence of a fixed infra- structure. They are particularly suited for communi- cation in disaster-affected areas, coordinating military operations, and sensing environmental conditions With the growing availability of supporting hardware and decreasing equipment cost, ad-hoc networking based applications are proliferating. Meshes of wire- less nodes are being deployed in cities and housing communities to…  相似文献   

13.
前期已经对某电动汽车进行基于能量利用率的传动比设计,设计出自动变速器传动方案及其尺寸。本文采用Solidworks软件建立箱体结构模型,并以Solidworks Simulation对箱体前盖和后盖分别进行有限元分析,得出最大应力值及出现位置。结果表明,所设计的自动变速器既满足能量利用率最优又符合静强度要求。  相似文献   

14.
Totransmitthemultimediadataovertheinternet ,pre encodedvideobitstreamsarepreferablebecauseofthelimitofthenetworkbandwidth .Inmostcases ,theencodershouldknowthechannelcharacteristicsinad vanceandencodethemasparameters .Consequently ,theflexibilityisreduced .Theratecontrolisemployedtocontroltheoutputbitrateaccordingtonetworkcondi tions.Forwirelessnetworks ,theirbandwidthsaremuchmorelimitedthanwirenetworks.Soratecontrolbecomesespeciallyimportantfortransmittingmultimediaoverthewirelessdomains[1- …  相似文献   

15.
对国家标准GB/T14549-93《电能质量 公用电网谐波》中谐波电压限值的确定作了说明。分析了0.38kV电压等级的电压总谐波畸变率限值取5%为国家标准的合理性。提出了相邻各电压等级总谐波畸变率限值所应取比值的计算式。并结合我国电网枢纽点额定容量和短路容量的平均情况,提出了一个典型的、包含0.38、10、35、110kV以及220kV各电压等级的供电网络接线。参照其计算结果,确定了其它电压等级总谐波畸变率限值。  相似文献   

16.
为了解决低对比度成像条件下传统三维轮廓重建算法精度偏低的问题,提出一种基于邻域距离最小化准则、由粗到细的高精度轮廓三维重建算法。首先使用 Canny 算子对目标图像进行边缘检测,再利用目标形状、尺寸等先验信息剔除分割出的虚假目标边缘。随后,计算边缘点法线方向上的梯度加权值作为工件初始化轮廓,根据左右一致性原则筛选出粗匹配点对,在匹配点对邻域附近使用亚像素进行精细搜索,利用邻域距离最小化准则估算出当前最佳亚像素匹配点对,并将其用于激光刻形工件的尺寸测量,总体精度可达 0.1mm。该方法有效降低了轮廓重建算法对边缘定位精度的依赖,同时提高了轮廓重建精度。  相似文献   

17.
缓存替换机制是内容中心网络研究的重点,在解决网络时延与网络带宽拥堵等问题中发挥着重要作用。针对目前边缘侧量节点设备缓存空间的有限性,提出一种基于猴群算法的优化方案。该方案可合理地对边缘设备缓存内容进行置换,有效提高边缘量设备请求命中率。通过在猴群算法的猴群爬过程中引入文件流行度等引导因子、在望过程中改进猴群视野范围等方法找到最优解。仿真实验结果显示了不同大小的边缘设备缓存空间请求命中率。与传统算法相比,该方案可有效提高请求命中率。  相似文献   

18.
在量子通信过程中,通信质量主要受到量子噪声、通信节点数、纠缠粒子数等因素影响,为得到更适合实际应用的通信路由,对相位阻尼信道进行研究。在以最小等效阻尼系数为度量的最佳中继路由算法基础上进行改进,给出一种综合性路由度量的最佳路由选择方案。该方案充分考虑了对通信路由影响较大的几个因子,并采用路径先验方案以避免路径失效后网络进行通信请求。理论分析与仿真对比结果表明,该路由协议使路径节点中的最小纠缠粒子对数得到明显提高,从而提高了网络稳定性。  相似文献   

19.
为了解决传统算法QR码定位中出现QR码失真,或旋转时出现较弱鲁棒性的现象,提出一种新型QR码自适应定位算法。在算法研究过程中,首先使用自适应阈值算法解决不均匀照明的影响,在此基础上提出一种基于轮廓跟踪与轮廓筛选的定位方法。实验结果表明,与传统QR码定位算法相比,该算法定位准确率提高了30%,且定位速度提升了17%,可见该定位算法能够很好地应用于QR码定位。  相似文献   

20.
采用索贝尔算子检测边缘,最大类间方差法把图像二值化,通过数学形态学处理得到改进的二值图像,掏空内部点得到边界点,进行边界跟踪把轮廓从复杂的图像中提取出来。传统的边缘检测得到的边缘不一定是单像素点,而此方法实现单像素点的轮廓提取,实验证明该方法行之有效。  相似文献   

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