简介:Inthestrapdowninertialnavigationsystem,theFiberOpticalGyro(FOG)musthavehighprecisiontogiveaccuratenavigationinformation.Inthispaper,adigitalclosedloopdetectionmethodbasedontherampwavemodulatingtechnigueisintroduced.DSPandFPGAhavemanyadvantagesindigitalsignalprocessing.Inthedesign,byusingDSP,acomplexarithmeticoperationiscompletedtomeettheneedsofclosedloopcontrolofFOGwithinashorttime.AllkindsofcontrolsignalsareproducedeasilybyFPGA,underwhichDSPcouldworkproperly.CombiningtheDSPandFPGA,thedetectingmethodisimplementedsuccessfully.Intheend,theresultoftestandperformanceisgiven.FromtheresultwecanconcludethattheprecisionofFOGisimprovedandthenoisesarelimitedtoalowlevel.
简介:ThebackdoororinformationleakofWebserverscanbedetectedbyusingWebMiningtechniquesonsomeabnormalWeblogandWebapplicationlogdata.ThesecurityofWebserverscanbeenhancedandthedamageofillegalaccesscanbeavoided.Firstly,thesystemfordiscoveringthepatternsofinformationleakagesinCGIscriptsfromWeblogdatawasproposed.Secondly,thosepatternsforsystemadministratorstomodifytheircodesandenhancetheirWebsitesecuritywereprovided.Thefollowingaspectsweredescribed:oneistocombinewebapplicationlogwithweblogtoextractmoreinformation,sowebdataminingcouldbeusedtomineweblogfordiscoveringtheinformationthatfirewallandInformationDetectionSystemcannotfind.AnotherapproachistoproposeanoperationmoduleofwebsitetoenhanceWebsitesecurity.Inclusterserversession,Density-BasedClusteringtechniqueisusedtoreduceresourcecostandobtainbetterefficiency.
简介:Real-timemodelingandsimulationofflightsystemarethekeypartsofsimulator.Afterdescribingthearchitectureofsimulatorforanewerfighter,authorpresentsthecompositionofflightsystemanditsmathematicmodels.Inthispaper,aircraftisregardedasanelasticflightbody.AndanewintegratedalgorithmwhichcanremedytheshortcomingofEulermethodandfour-elementmethodisusedtocalculatetheEuleriananglesofaircraft.Finally,thesoftwareimplementationoftheflightsystemisgiveninthepaper.