简介:Anoutsourcedatabaseisadatabaseserviceprovidedbycloudcomputingcompanies.Usingtheoutsourcedatabasecanreducethehardwareandsoftware'scostandalsogetmoreefficientandreliabledataprocessingcapacity.However,theoutsourcedatabasestillhassomechallenges.Iftheserviceproviderdoesnothavesufficientconfidence,thereisthepossibilityofdataleakage.Thedatamayhasuser'sprivacy,sodataleakagemaycausedataprivacyleak.Basedonthisfactor,toprotecttheprivacyofdataintheoutsourcedatabasebecomesveryimportant.Inthepast,scholarshaveproposedk-anonymitytoprotectdataprivacyinthedatabase.Itletsdatabecomeanonymoustoavoiddataprivacyleak.Butk-anonymityhassomeproblems,itisirreversible,andeasiertobeattackedbyhomogeneityattackandbackgroundknowledgeattack.Lateron,scholarshaveproposedsomestudiestosolvehomogeneityattackandbackgroundknowledgeattack.Buttheirstudiesstillcannotrecoverbacktotheoriginaldata.Inthispaper,weproposeadataanonymitymethod.Itcanbereversibleandalsopreventthosetwoattacks.Ourstudyisbasedontheproposedr-transform.Itcanbeusedonthenumerictypeofattributesintheoutsourcedatabase.Intheexperiment,wediscussedthetimerequiredtoanonymizeandrecoverdata.Furthermore,weinvestigatedthedefenseagainsthomogeneousattackandbackgroundknowledgeattack.Attheend,wesummarizedtheproposedmethodandfutureresearches.
简介:AnewmethodisproposedtoimplementanopticalS-Rflip-flopbypolarizationencodedlightsignal,necessaryopticalnonlinearmaterialandhalf-waveplate.Inthissystemtherealtimespeedofoperationcanbeachieved,andatthetimeoftransmissiontheaveragepowerofabyteremainsconstant.Thispolarizationencodedflip-flopcanactasamemorycell.
简介:Inthelaserwarningsystem,anon-mechanicalscanningFabry-Perot(F-P)typelaserwarningmethodanditscrucialcomponent-laserincidentsensordesignmethodarebroughtout,andtheF-Petalonwiththeinterferometricfiltercombinationisadopted.Fortheincidentlaserpulsewithacertainwavelength,thetransmittancedifferenceoftheinterferometricfiltersisindependentwithpolarizationofincidentlight,anddescendsalmostlinearlyastheincidentanglegetswider.Alaserincidentanglesensorexperimentalplatformisbuiltup,andtheexperimentiscarriedoutwithagivenlaserrangefinder.Astheresultsindicate,whentheincidentangleislessthan5o,thetransmittancedifferencemeasuredbythelaseranglesensorissignificantlylower,andthedeviationismorethan10%.Whiletheincidentangleisgreaterthan10o,thedeviationisreducedsignificantly.