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简介：一个基站的信号覆盖是有一定范围的，为了能让无线电话在一个很大区域内(如一个市)都能打电话，就需要很多基站，使信号能覆盖这片区域。这样，当用户在移动过程中通话，就会发生切换。这种切换常规情况下会有1～2秒，有时有短暂停顿的感

简介：Digitalsignatureisoneofthemostimportantcryptographicprimitives.WeproposedanewdigitalsignatureschemebasedonCatalano’strapdoor.SinceCatalano’strapdoorismoreefficientthanexistingtrapdoorsinnumbertheory,ourschemeneednotmodularexponentiationbutseveralmodularmultiplicationsinthesigningalgorithm.Wealsoprovedourschemeisprovablysecureagainstadap-tivelychosenmessageattackbyusingtheForkinglemma.

简介：CRTCornercuttingtubeisconsideredasadefinitiverejectandwillbesenttoreclaimatalltimes.Itcausedlotsofmaterialloss.Inthispaper,anoveltechnologyusedtosaveCRTscornercuttingtubeispresentedfirstly.AsetofrepairsystemhasbeensuccessfullydevelopedtorepairCRTscornercuttingtube.Then,theprocesstechnologyforcornercuttingrepairhasbeenexcogitatedbyempiricalstudies.Finally,thecorrelativeperformancesofrepairedtubeareevaluated.Theexperimentalresultsshowthatthequalityofrepairedtubehasnodifferencewiththatofnormalproduct.Therepairyieldhasreachedabove97percent.Thisnewtechnologyhascontributedtoimprovingtheproductionyield,reducingthematerialconsumptionanddecreasingthecostofcolorCRTproduction.

简介：Thisletterintroducesthedesignideas,simulationandtestresultsofanS-bandklystronwithbandwidthof11%,whichwasdevelopedbytheInstituteofElectronics,ChineseAcademyofSciences(IECAS).Onthepeakpowerlevelof800kW,theefficiencyofklystronismorethan30%;thegainismorethan41dB;theequal-drivingrelativeinstantaneousbandwidthisover11%;theaveragepowerislargerthan8kW,andthepowerfluctuationwithinbandwidthislessthan1.5dB.

简介：ThecharacteristicofEDFAinWDMsystemisanalyzed.ThesimulationsystembasedonthearchitectureoftheChinaInformationNetwork(CAINONET)isintroduced,andtheinfluenceofnoisefigure,gainunflatnessandoutputpowerofEDFAontheBERperformanceandscaleofnetworkisinvestigated.Moreover,theinfluenceofnoisefigureisstudiedwithdifferentcrosstalk.Meanwhile,itisindicatedthatitisimportanttoapplythe"nodeisolationprinciple"intheopticalnetwork.Theresearchresultscanprovidethevaluablereferenceforthepracticalconstructionofallopticalnetwork.

简介：ThislettergivesarandomconstructionforLowDensityParityCheck(LDPC)codes,whichusesaniterativealgorithmtoavoidshortcyclesintheTannergraph.TheconstructionmethodhasgreatflexiblechoiceinLDPCcode'sparametersincludingcodelength,coderate,theleastgirthofthegraph,theweightofcolumnandrowintheparitycheckmatrix.ThemethodcanbeappliedtotheirregularLDPCcodesandstrictregularLDPCcodes.Systemiccodeshavemanyapplicationsindigitalcommunication,sothisletterproposesaconstructionofthegeneratormatrixofsystemicLDPCcodesfromtheparitycheckmatrix.Simulationsshowthatthemethodperformswellwithiterativedecoding.

简介：介绍了S波段极低噪声超导滤波放大组件的设计过程,采用了低温仿真建模和拓扑结构优化设计关键技术。该组件将用于接收系统中的的低温接收前端,能提高雷达的灵敏度和有效作用距离。该组件由超导滤波器和低温放大器组成,具有体积小、重量轻、可靠性高等特点。

简介：在有低极化模式的40个Gb/s系统分散(PMD)纤维，一阶的PMD是有相当小的价值的dominate因素。由一个电的极化控制器(PC)组成的一个适应PMD赔偿者，维持纤维(PMF)的极化的节，极化(DOP)的度察觉者和一个反馈控制模块在40Gb/sNSFCNet被采用。这个赔偿者有简单结构和高速度，它能适应地补偿一阶的PMD直到20ps，平均寻找时间是2ms。CLC数字TN929.11

简介：S模式ADS-B系统概念结合了自动相关监视和S模式信标雷达,是一种监视和数据链的综合系统,包括机载设备和地面设备,它是在S模式二次监视雷达的基础上发展起来的一种新型的空管监视系统,正逐步得到国际上的广泛应用。介绍了S模式ADS-B的原理及应用范围,并对其性能进行了详细的对比分析。

简介：Transmissionperformanceofelectroabsorptionmodulatorin10Gb/stransmissionsystemshasbeensimulatedandanalyzedundertheconditionoftakingintoaccountthechirp,extinctionratio,transmissivityandrise/falltime.ResultsshowthatshorttransmissiondistancewithoutEDFAafterEAMcanbeusedinfuturemetropolitanareanetwork,butthetransmissivitymustbecarefullyconsidered.Thesamplingtimerangeanddecisionlevelcanbeoptimizedtoreducethebiterrorratio.

简介：ItiswellknownthatthealgebraicexpressionofASSS-boxisverysimpleandonly9termsareinvolved.Hence,AESsecurityissuspectedalthoughthereisnovulnerabilityonitsofar.ToeliminatetheweaknessofextremelysmalltermsinthealgebraicexpressionofAESS-box,oneimprovedAESS-boxisproposed,whichpreservesthealgebraicdegreeinvariablebutsignificantlyincreasesthenumberofitsalgebraicexpressiontermsfrom9to255.Atthesametime,Booleanfunctionhasgoodcharactersinbalanceandstrictavalanchecriterion(SAC),etc.Finally,itisprovedthattheimprovedAESS-boxschemeissecuregainstthepowerfulknowndifferentialandlinearcryptanalysis.

简介：一个光标签的标签扑灭比率和分散赔偿正在交换传播系统优化，它采用40-Gb/s回来到调音的零微分阶段移动(RZ-DPSK)用622-Mb/s振幅移动调音标记的收费载重(问)控制数据。在我们的计划，收费载重和标签的接收装置敏感分别地完成-27.8dBm和-33.5dBm。在在40km上播送了以后，60km和80km挑选模式纤维(SMF)(与分散赔偿)分别地，收费载重能没有力量惩罚被恢复，当标签能与不到2dB惩罚被恢复时。

简介：大屏幕系统中央控制器和客户端／服务器（C／S）架构控制软件在安装时，存在部署环境适应性差和功能扩展复杂等不足。提出将浏览器／服务器（B／S）软件架构应用到大屏幕系统控制软件中，可通过网页浏览器实现大屏幕设备的管理控制。基于B／S架构的大屏幕控制系统，介绍了大屏幕系统组成、基于B／S架构的控制系统网络拓扑结构、系统软件架构以及功能模块划分及实现。同时分析了控制系统与大屏幕设备的交互原理。应用实例表明，该系统完成了设计目标。

简介：为了研究车载天线间的电磁兼容性,采用ANSA软件对车辆模型进行简化处理,建立了全尺寸的车辆电磁仿真简化模型。基于广义S参数理论,给出了收发天线间的电磁耦合度表达式。利用CST软件仿真分析了理想导体平面上收发天线对的电磁耦合度,以及车辆车载收发天线间的电磁耦合度。结果表明,随着天线间距的减小,车载天线间的耦合度非线性变化,但基本呈增加趋势。收发天线工作于谐振频率62.5MHz时,电磁耦合度最小,谐振频率附近出现了两个电磁耦合度最大峰值。发射天线的三次谐波与接收天线的电磁耦合度较强。

简介：<正>据《电子材料》2002年第11期报道,日立制作所日前开发了用于下一代光网络系统的40Gbit/s光调制器。在该光调制器中使用了集成专用驱动电路的小型光传输模块。在无需光放大器时,其传输距离达2Km。该器件在与发射机组装时具有完整的阻抗匹配性,且容易与周边电路集成。为了与周边电路实现匹配,将InP—HBT光调制器驱动器集成于同一封装体内。该器件的光输出性能为1.3dBm。

简介：Basedonuser’sin-degreedistribution,traditionalrankingalgorithmsofuser’sweightusuallyneglecttheconsiderationsofthedifferencesamonguser’sfollowersandthefeaturesofuser’stweets.Inordertoanalyzethefactorswhichimpactonuser’sweight,undertheanalysisofthedatacollectedfromSINAMicroblognetwork,thispaperdiscoversthatuserinfluenceandactivedegreesarethedominantfactorsforthisissue.Theproposedalgorithmevaluatesuserinfluencebyuser’sfollowernumber,theinfluenceofuser’sfollowersandthereciprocitybetweenusers.User’sactivedegreeismodeledbyuser’sparticipationandthequalityofuser’stweets.Themodelsaretestedbydifferentdatagroupstoconfirmtheparametersforthefinalcalculation.Eventually,thispapercomparesthecomputationalresultswiththeuser’srankingordergivenbytheSINAofficialapplication.Theperformanceofthisalgorithmpresentsastrongerstabilityonthefluctuantrangeofthevalueofuser’sweight.

简介：Amonolithicclock-recoverycircuitusedin622Mb/sopticalcommunicationsystemisdesigned,whichisbasedonthephase-lockedlooptheory,,andusesbipolartransistormodel.Itovercomestheshortcomingofclockrecoverymethodbasedonfilter,andimplementsmonolithicclock-recoveryIC.Thedesignedcircuitsincludephaedetector,voltage-controlledoscillatorandloopfilter.Amongthem,thevoltage-controloscillatorisamodifiedtwo-stageringoscillator,whichprovidesquadratureclocksignalsandpresentswidevoltage-controlledrangeandhighvoltage-controllingsensitivity.

简介：Inthispaper,anewmodelbasedonanimprovedBrentKung(BK)parallelprefixnetwork(PPN)algorithmisproposedandrealizedinthefieldprogrammablegatearray(FPGA).Thismodelisemployedintheimplementationof20Gb/sdifferentialquadraturephase-shiftkeying(DQPSK)precoderin40Gb/spolarizationdivisionmultiplex(PolDM)DQPSKsystem.Inthecomputationprocess,thecomputationcomplexity(area)optimizationwithfan-outlimitedisachieved.Intheimplementation,770FPGAsliceregistersareutilized,whichsaveabout60%logicresourcescomparedwiththepreviousKoggeStone(KS)algorithm.

简介：安全性是对雷达装备的一项重要要求，涉及到雷达的设计、生产、使用、管理等诸多方面。鉴于影响安全的因素多和不确定性，提出用模糊综合评判法进行量化处理，对雷达装备安全性进行综合评价。根据影响装备安全的因素建立了安全性指标体系，并建立了模糊综合评判模型，利用D—S证据融合法确定评价因素的权重，对装备安全性进行综合评估。根据评估结果，以指导雷达系统的安全性设计、生产与使用。