简介:Becauseofitspotentialapplicationsinagriculture,environmentmonitoringandsoon,wirelessundergroundsensornetwork(WUSN)hasbeenresearchedmoreandmoreextensivelyinrecentyears.ThemainandmostimportantdifferenceofWUSNtoterrestrialwirelesssensornetwork(WSN)isthechannelcharacteristics,whichdeterminesthedesignmethodologyofit.Inthispaper,thepropagationcharacterofelectromagnetic(EM)waveinthenearsurfaceWUSNisanalyzed,aswellasthepathlossmodelofitisgiven.Inaddition,theinfluenceofhuman'sankletothechannelcharacteristicsofnearsurfaceWUSNisinvestigatedbyelectromagnetictheoryanalysis,simulationandexperiment.AnovelpathlossmodelofnearsurfaceWUSNwhichtakestheinterferenceofhuman'sankleintoconsiderationisproposed.ItisverifiedthattheexistingofhumanabovetheWUSNsystemmaycauseadditionalattenuationtothesignalofnearsurfaceWUSNwhichpropagatesaslateralwavealongtheground.Moreover,therelationoftheattenuationandoperatingfrequencyisdeduced,whichgivesareferencetoextendthefrequencybandappliedinWUSN.
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。