学科分类
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3 个结果
  • 简介:Inthestrapdowninertialnavigationsystem,theFiberOpticalGyro(FOG)musthavehighprecisiontogiveaccuratenavigationinformation.Inthispaper,adigitalclosedloopdetectionmethodbasedontherampwavemodulatingtechnigueisintroduced.DSPandFPGAhavemanyadvantagesindigitalsignalprocessing.Inthedesign,byusingDSP,acomplexarithmeticoperationiscompletedtomeettheneedsofclosedloopcontrolofFOGwithinashorttime.AllkindsofcontrolsignalsareproducedeasilybyFPGA,underwhichDSPcouldworkproperly.CombiningtheDSPandFPGA,thedetectingmethodisimplementedsuccessfully.Intheend,theresultoftestandperformanceisgiven.FromtheresultwecanconcludethattheprecisionofFOGisimprovedandthenoisesarelimitedtoalowlevel.

  • 标签: 光纤光学陀螺仪 信号探测 相位调制 DSP FPGA 船舶导航设备
  • 简介:ThebackdoororinformationleakofWebserverscanbedetectedbyusingWebMiningtechniquesonsomeabnormalWeblogandWebapplicationlogdata.ThesecurityofWebserverscanbeenhancedandthedamageofillegalaccesscanbeavoided.Firstly,thesystemfordiscoveringthepatternsofinformationleakagesinCGIscriptsfromWeblogdatawasproposed.Secondly,thosepatternsforsystemadministratorstomodifytheircodesandenhancetheirWebsitesecuritywereprovided.Thefollowingaspectsweredescribed:oneistocombinewebapplicationlogwithweblogtoextractmoreinformation,sowebdataminingcouldbeusedtomineweblogfordiscoveringtheinformationthatfirewallandInformationDetectionSystemcannotfind.AnotherapproachistoproposeanoperationmoduleofwebsitetoenhanceWebsitesecurity.Inclusterserversession,Density-BasedClusteringtechniqueisusedtoreduceresourcecostandobtainbetterefficiency.

  • 标签: WEB 网络安全 数据挖掘 计算机网络 逻辑推理
  • 简介:Real-timemodelingandsimulationofflightsystemarethekeypartsofsimulator.Afterdescribingthearchitectureofsimulatorforanewerfighter,authorpresentsthecompositionofflightsystemanditsmathematicmodels.Inthispaper,aircraftisregardedasanelasticflightbody.AndanewintegratedalgorithmwhichcanremedytheshortcomingofEulermethodandfour-elementmethodisusedtocalculatetheEuleriananglesofaircraft.Finally,thesoftwareimplementationoftheflightsystemisgiveninthepaper.

  • 标签: 实时模型 飞机 飞行模拟器 欧拉角 六DOF数学模型