简介:Inthisagecharacterizedbyrapidgrowthinthevolumeofdata,datadeidentificationtechnologieshavebecomecrucialinfacilitatingtheanalysisofsensitiveinformation.Forinstance,healthcareinformationmustbeprocessedthroughdeidentificationproceduresbeforebeingpassedtodataanalysisagenciesinordertopreventanyexposureofpersonaldetailsthatwouldviolateprivacy.Assuch,privacyprotectionissuesassociatedwiththereleaseofdataanddatamininghavebecomeapopularfieldofstudyinthedomainofbigdata.Asastrictandverifiabledefinitionofprivacy,differentialprivacyhasattractednoteworthyattentionandwidespreadresearchinrecentyears.Inthisstudy,weanalyzetheadvantagesofdifferentialprivacyprotectionmechanismsincomparisontotraditionaldeidentificationdataprotectionmethods.Furthermore,weexamineandanalyzethebasictheoriesofdifferentialprivacyandrelevantstudiesregardingdatareleaseanddatamining.
简介:Thisarticlepresentsadatamanagementsolutionbasedonthedatadistributionservice(DDS)communicationmodel.ThebasicDDScommunicationmodelconsistsofaunidirectionaldataexchangewhereapplicationsthatpublishdata'push'therelevantdata,whichisupdatedtothelocalcachesofco-locatedsubscriberstothedata[1].DDShasnospecifiedcenternodetoforwarddatapacketsandmaintainthecommunicationdata.Thistypeofpublish-subscribe(P/S)modelpresentsintegrityandconsistencychallengesindatamanagement.Unlikepeer-to-peer(P2P)distributedstorage,DDSapplicationshaveahardreal-timeenvironmentandfewerdatafeatures,andthecoreproblemisensuringtheintegrityandconsistencyofdataindistributedsystemsunderthishardreal-timeenvironment.ThisarticlebeginswithabriefintroductionofthecommunicationmodelusedbyDDS,thenanalyzespersistentdatamanagementproblemscausedbysuchmodel,andprovidesanappropriatesolutiontotheseproblems.Thissolutionhasbeenimplementedinaprototypesystemofthereal-timeservicebus(RTSB)ofTsinghuaUniversity.
简介:Theapplicationofdataenvelopmentanalysis(DEA)asamultiplecriteriadecisionmaking(MCDM)techniquehasbeengainingmoreandmoreattentioninrecentresearch.InthepracticeofapplyingDEAapproach,theappearanceofuncertaintiesoninputandoutputdataofdecisionmakingunit(DMU)mightmakethenominalsolutioninfeasibleandleadtotheefficiencyscoresmeaninglessfrompracticalview.ThispaperanalyzestheimpactofdatauncertaintyontheevaluationresultsofDEA,andproposesseveralrobustDEAmodelsbasedontheadaptationofrecentlydevelopedrobustoptimizationapproaches,whichwouldbeimmuneagainstinputandoutputdatauncertainties.TherobustDEAmodelsdevelopedarebasedoninput-orientedandoutputorientedCCRmodel,respectively,whentheuncertaintiesappearinoutputdataandinputdataseparately.Furthermore,therobustDEAmodelscoulddealwithrandomsymmetricuncertaintyandunknown-but-boundeduncertainty,inbothofwhichthedistributionsoftherandomdataentriesarepermittedtobeunknown.TherobustDEAmodelsareimplementedinanumericalexampleandtheefficiencyscoresandrankingsofthesemodelsarecompared.TheresultsindicatethattherobustDEAapproachcouldbeamorereliablemethodforefficiencyevaluationandrankinginMCDMproblems.
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:GuestEditorsProf.TaoZhouUniv.ofElectronicScienceandTechnologyofChinazhutouster@gmail.comProf.ZenglinXuUniv.ofElectronicScienceandTechnologyofChinazenglin@gmail.comInthisdigitalera,enormousamountsofdataareubiquitousandpervasive,whichareknownasBigData.Thesedataareaboutdifferentdomains,fromdifferentsources,andindifferentformats.Inordertomanipulate,integrate,andutilizethe
简介:Acompressionalgorithmisproposedinthispaperforreducingthesizeofsensordata.Byusingadictionary-basedlosslesscompressionalgorithm,sensordatacanbecompressedefficientlyandinterpretedwithoutdecompressing.Thecorrelationbetweenredundancyofsensordataandcompressionratioisexplored.Further,aparallelcompressionalgorithmbasedonMapReduce[1]isproposed.Meanwhile,datapartitionerwhichplaysanimportantroleinperformanceofMapReduceapplicationisdiscussedalongwithperformanceevaluationcriteriaproposedinthispaper.Experimentsdemonstratethatrandomsamplerissuitableforhighlyredundantsensordataandtheproposedcompressionalgorithmscancompressthosehighlyredundantsensordataefficiently.
简介:Thedatausedintheprocessofknowledgediscoveryoftenincludesnoiseandincompleteinformation.Theboundariesofdifferentclassesofthesedataareblurandunobvious.Whenthesedataareclusteredorclassified,weoftengetthecoveringsinsteadofthepartitions,anditusuallymakesourinformationsysteminsecure.Inthispaper,optimalpartitioningofincompletedataisresearched.Firstly,therelationshipofsetcoverandsetpartitionisdiscussed,andthedistancebetweensetcoverandsetpartitionisdefined.Secondly,theoptimalpartitioningofgivencoverisresearchedbythecombingandpartingmethod,acquiringtheoptimalpartitionfromthreedifferentpartitionssetfamilyisdiscussed.Finally,thecorrespondingoptimalalgorithmisgiven.Therealwirelesssignalsofftencontainalotofnoise,andtherearemanyerrorsinboundarieswhenthesedataisclusteredbasedonthetradionalmethod.Inourexperimant,theproposedmethodimprovescorrectrategreatly,andtheexperimentalresultsdemonstratethemethod’svalidity.
简介:Thispaperpresentsafault-detectionmethodbasedonthephasespacereconstructionanddataminingapproachesforthecomplexelectronicsystem.TheapproachforthephasespacereconstructionofchaotictimeseriesisacombinationalgorithmofmultipleautocorrelationandΓ-test,bywhichthequasi-optimalembeddingdimensionandtimedelaycanbeobtained.Thedataminingalgorithm,whichcalculatestheradiusofgyrationofunit-masspointaroundthecentreofmassinthephasespace,candistinguishthefaultparameterfromthechaotictimeseriesoutputbythetestedsystem.Theexperimentalresultsdepictthatthisfaultdetectionmethodcancorrectlydetectthefaultphenomenaofelectronicsystem.
简介:Networktrafficclassificationaimsatidentifyingtheapplicationtypesofnetworkpackets.ItisimportantforInternetserviceproviders(ISPs)tomanagebandwidthresourcesandensurethequalityofservicefordifferentnetworkapplications.However,mostclassificationtechniquesusingmachinelearningonlyfocusonhighflowaccuracyandignorebyteaccuracy.TheclassifierwouldobtainlowclassificationperformanceforelephantflowsastheimbalancebetweenelephantflowsandmiceflowsonInternet.Theelephantflows,however,consumemuchmorebandwidththanmiceflows.Whentheclassifierisdeployedfortrafficpolicing,thenetworkmanagementsystemcannotpenalizeelephantflowsandavoidnetworkcongestioneffectively.Thisarticleexploresthefactorsrelatedtolowbyteaccuracy,andsecondly,itpresentsanewtrafficclassificationmethodtoimprovebyteaccuracyattheaidofdatacleaning.Experimentsarecarriedoutonthreegroupsofreal-worldtrafficdatasets,andthemethodiscomparedwithexistingworkontheperformanceofimprovingbyteaccuracy.Experimentshowsthatbyteaccuracyincreasedbyabout22.31%onaverage.Themethodoutperformstheexistingoneinmostcases.
简介:Timelyandcost-efficientmulti-hopdatadeliveryamongvehiclesisessentialforvehicularad-hocnetworks(VANETs),andvariousroutingprotocolsareenvisionedforinfrastructure-lessvehicle-to-vehicle(V2V)communications.Generally,whenapacket(oraduplicate)isdeliveredoutoftheroutingpath,itwillbedropped.However,weobservethatthesepackets(orduplicates)mayalsobedeliveredmuchfasterthanthepacketsdeliveredalongtheoriginalroutingpath.Inthispaper,weproposeanoveltreebasedroutingscheme(TBRS)forultilizingthedroppedpacketsinVANETs.InTBRS,thepacketisdeliveredalongaroutingtreewiththedestinationasitsroot.Andwhenthepacketisdeliveredoutitsroutingtree,itwon'tbedroptimmediatelyandwillbedeliveredforawhileifitcanarriveatanotherbranchofthetree.WeconducttheextensivesimulationstoevaluatetheperformanceofTBRSbasedontheroadmapofarealcitycollectedfromGoogleEarth.ThesimulationresultsshowthatTBRScanoutperformtheexistingprotocols,especiallywhenthenetworkresourcesarelimited.
简介:AnorthogonallymultiplexedQAM(OQAM)systemallowstransmissionspeedtobeveryclosetotheNyquistratewithlittlesensitivitytodelayandsignaldistortionsoftransmissionmediumwhenalargenumberofchannelsareused.Itscircuitcomplexitycanbelargelyovercomebyintroducingdigitalsignalprocessing(DSP)technology,Inthispaper,theimplementationofgroupbanddatamodemusingOQAMtechniqueispresented,whereOQAMsystemisrealizedbymeansofcascadingadiscretecosinetransformer(DCT)andaweightingnetwork.TheproperalgorithmofevaluatingFIRfilterandDCTprovidesfurtherreductionofthecomputationcomplexitywhichdropsto35.6%ofthatofHirosaki'sscheme[5].
简介:Toimprovedatacacheperformance,optimizingprogramdatalayoutbydatareorganizationhasbecomeanimportantmethodofdecreasingtheimpactofincreasinggapofspeedbetweenprocessorandmemory.Inthisarticle,astructuresplittingframeworkwithananalysismodelnamedstructurefieldrelationgraph(SFRG)ispresentedtooptimizeprogramdatalayout.TheSFRGcanbeusedtoquantifyrelationshipbetweenfields.Ithelpstofindanoptimallayoutforstructureaswellastheoptimalprogramdatalayout.AndthedatacacheperformanceisimprovedthroughSFRG-basedstructuresplitting.Experimentsshowthatthisframeworkiseffectiveinoptimizingprogramdatalayoutandimprovingtheperformanceofdatacacheandwholeprogram.
简介:ForthereliabilityandpowerconsumptionissuesofEthernetdatatransmissionbasedonthefieldprogrammablegatearray(FPGA),alow-powerconsumptiondesignmethodisproposed,whichissuitableforFPGAimplementation.Toreducethedynamicpowerconsumptionofintegratedcircuit(IC)design,theproposedmethodadoptsthedynamiccontroloftheclockfrequency.Formostofthetime,whentheportisintheidlestateorlower-ratestate,userscanreduceoreventurnoffthereadingclockfrequencyandreducetheclockflipfrequencyinordertoreducethedynamicpowerconsumption.Whenthereceivingrateishigh,thereadingclockfrequencywillbeimprovedtimelytoensurethatnodatawilllost.SimulatedandverifiedbyModelsim,theproposedmethodcandynamicallycontroltheclockfrequency,includingthedynamicswitchingofhigh-speedandlow-speedclockfliprates,orstopoftheclockflip.
简介:Hidingdatainthedeoxyribosenucleicacid(DNA)canfacilitatetheauthenticationandannotationofimportantplantvarietyrights.Agrantofplantvarietyrightsforanewplantvarietygivesyoutheexclusiverighttoproduceforsaleandsellpropagatingmaterialofthevariety.Digitalwatermarkingtechniqueshavebeenproposedforawiderangeofapplications,includingownershipprotection,copycontrol,annotation,andauthentication.However,existingdatahidingmethodsforDNAchangethefunctionalitiesofDNAsequences,whichinducemorphologicalchangesinbiologicalpatterns.ThispaperproposesahighcapacitydatahidingschemeforDNAwithoutchangingthefunctionalitiesofDNAsequences.Thisschemeadaptivelyvariestheembeddingprocessaccordingtotheamountofhiddendata.Experimentalresultsshowthattheproposedschemegivesasignificantlyimprovedhidingperformancethanpreviousschemes.Andtherobustnessandsecurityissuesarealsoanalyzed.
简介:Theperformanceofadaptivebeamformingtechniquesislimitedbythenonhomogeneouscluttersce-nario.AnaugmentedKrylovsubspacemethodisproposed,whichutilizesonlyasinglesnapshotofthedataforadaptiveprocessing.ThenovelalgorithmputstogetheradatapreprocessorandadaptiveKrylovsubspacealgo-rithm,wherethedatapreprocessorsuppressesdiscreteinterferenceandtheadaptiveKrylovsubspacealgorithmsuppresseshomogeneousclutter.Thenovelmethodusesasinglesnapshotofthedatareceivedbythearrayantennatogenerateacancellationmatrixthatdoesnotcontainthesignalofinterest(SOI)component,thus,itmitigatestheproblemofhighlynonstationaryclutterenvironmentandithelpstooperateinreal-time.Thebenefitofnotrequiringthetrainingdatacomesatthecostofareduceddegreeoffreedom(DOF)ofthesystem.Simulationillus-tratestheeffectivenessincluttersuppressionandadaptivebeamforming.Thenumericresultsshowgoodagreementwiththeproposedtheorem.