简介：Intrusiondetectioncanbeessentiallyregardedasaclassificationproblem,namely,dis-tinguishingnormalprofilesfromintrusivebehaviors.Thispaperintroducesboostingclassificationalgorithmintotheareaofintrusiondetectiontolearnattacksignatures.Decisiontreealgorithmisusedassimplebaselearnerofboostingalgorithm.Furthermore,thispaperemploysthePrincipleCom-ponentAnalysis(PCA)approach,aneffectivedatareductionapproach,toextractthekeyattributesetfromtheoriginalhigh-dimensionalnetworktrafficdata.KDDCUP99datasetisusedintheseex-perimentstodemonstratethatboostingalgorithmcangreatlyimprovetheclassificationaccuracyofweaklearnersbycombininganumberofsimple“weaklearners”.Inourexperiments,theerrorrateoftrainingphaseofboostingalgorithmisreducedfrom30.2%to8%after10iterations.Besides,thispaperalsocomparesboostingalgorithmwithSupportVectorMachine(SVM)algorithmandshowsthattheclassificationaccuracyofboostingalgorithmislittlebetterthanSVMalgorithm’s.However,thegeneralizationabilityofSVMalgorithmisbetterthanboostingalgorithm.

简介：Themeasurementtechniquesoffemtosecondspectroscopyareeffectivemethodtoinvestigateultrafastdynamics,theyarewidelyusedinthefieldsofphysics,chemistryandbiology.Inthispaper,theprinciple,experimentsetupandtheapproachestodealwiththeexperimentdatawerepresented.Thendifferentmeasurementtechniquessuchastransientabsorptionspectroscopy,photonechoes,opticalKerreffectanddegeneratefour-wavemixingwereexplainedwithspecialexamples.Atlast,theapplicationprospectofmeasurementtechniquesoffemtosecondspectroscopywasforecasted.

简介：Modernnetworksystemshavemuchtroubleinsecurityvulnerabilitiessuchasbufferoverflow,bugsinMicrosoftInternet,sensornetworkroutingprotocoltoosimple,securityflawsofapplications,andoperatingsystems.Moreover,wirelessdevicessuchassmartphones,personaldigitalassistants(PDAs),andsensorshavebecomeeconomicallyfeasiblebecauseoftechnologicaladvancesinwirelesscommunicationandmanufacturingofsmallandlow-costsensors.Therearetypologiesofvulnerabilitiestobeexploitedinthesedevices.Inordertoimprovesecurities,manymechanismsareadopted,includingauthentication,cryptography,accesscontrol,andintrusiondetectionsystems(IDS).Ingeneral,intrusiondetectiontechniquescanbecategorizedintotwogroups:misusedetectionandanomalydetection.Themisusedetectionsystemsusepatternsofwell-knownattacksorweakspotsofthesystemstoidentifyintrusions.Theweaknessofmisusedetectionsystemsisunabletodetectanyfuture(unknown)intrusionuntilcorrespondingattacksignaturesareintrudedintothesignaturedatabase.Anomalydetectionmethodstrytodeterminewhetherthedeviationisfromtheestablishednormalusagepatternsornot.Thecriticalsuccessofanomalydetectionreliesonthemodelofnormalbehaviors.

简介：Theautomaticdetectionoffacesisaveryimportantproblem.Theeffectivenessofbiometricauthenticationbasedonfacemainlydependsonthemethodusedtolocatethefaceintheimage.Thispaperpresentsahybridsystemforfacesdetectioninunconstrainedcasesinwhichtheillumination,pose,occlusion,andsizeofthefaceareuncontrolled.Todothis,thenewmethodofdetectionproposedinthispaperisbasedprimarilyonatechniqueofautomaticlearningbyusingthedecisionofthreeneuralnetworks,atechniqueofenergycompactionbyusingthediscretecosinetransform,andatechniqueofsegmentationbythecolorofhumanskin.Awholeofpictures(facesandnofaces)aretransformedtovectorsofdatawhichwillbeusedforlearningtheneuralnetworkstoseparatebetweenthetwoclasses.Discretecosinetransformisusedtoreducethedimensionofthevectors,toeliminatetheredundanciesofinformation,andtostoreonlytheusefulinformationinaminimumnumberofcoefficientswhilethesegmentationisusedtoreducethespaceofresearchintheimage.Theexperimentalresultshaveshownthatthishybridizationofmethodswillgiveaverysignificantimprovementoftherateoftherecognition,qualityofdetection,andthetimeofexecution.

简介：Thispaperpresentsahumandetectionsysteminavision-basedhospitalsurveillanceenvironment.Thesystemiscomposedofthreesubsystems,i.e.backgroundsegmentationsubsystem(BSS),humanfeatureextractionsubsystem(HFES),andhumanrecognitionsubsystem(HRS).ThecodebookbackgroundmodelisappliedintheBSS,thehistogramoforientedgradients(HOG)featuresareusedintheHFES,andthesupportvectormachine(SVM)classificationisemployedintheHRS.Bymeansoftheintegrationofthesesubsystems,thehumandetectioninavision-basedhospitalsurveillanceenvironmentisperformed.Experimentalresultsshowthattheproposedsystemcaneffectivelydetectmostofthepeopleinhospitalsurveillancevideosequences.

简介：Whenthereturnscomefromtwoormoreunresolvedtargets(thesignalsarenotresolvedinthefrequencyortimedomains)inamonopulseradarsystem,thedirection-of-arrival(DOA)estimateindicatedbythemonopulseratioisnotthetrueinformationofthetrackedtarget.Thenthetrackingsystemsisinfluenced.Anapproachhasbeenproposedtodetectwhetherthereturnscomefromasingletargetortwounresolvedtargets.Theaboveapproachisextendedfromtwotothreeunresolvedtargets.Thesimulationindicatesthatthedetectionprobabilityunderthethreeunresolvedtargetsisnotsuretoexceedthedetectionprobabilityunderthetwounresolvedtargets.

简介：Forfacedetectionundercomplexbackgroundandillumination,adetectionmethodthatcombinestheskincolorsegmentationandcost-sensitiveAdaboostalgorithmisproposedinthispaper.First,byusingthecharacteristicofhumanskincolorclusteringinthecolorspace,theskincolorareainYCbCrcolorspaceisextractedandalargenumberofirrelevantbackgroundsareexcluded;thenforremedyingthedeficienciesofAdaboostalgorithm,thecost-sensitivefunctionisintroducedintotheAdaboostalgorithm;finallytheskincolorsegmentationandcost-sensitiveAdaboostalgorithmarecombinedforthefacedetection.Experimentalresultsshowthattheproposeddetectionmethodhasahigherdetectionrateanddetectionspeed,whichcanmoreadapttotheactualfieldenvironment.

简介：Inordertoovercometheexistingdisadvantagesofofflinelasershockpeeningdetectionmethods,anonlinedetectionmethodbasedonacousticwavesignalsenergyisprovided.Duringthelasershockpeening,anacousticemissionsen-soratadefinedpositionisusedtocollecttheacousticwavesignalsthatpropagateintheair.Theacousticwavesignalissampled,stored,digitallyfilteredandanalyzedbytheonlinelasershockpeeningdetectionsystem.Thenthesystemgetstheacousticwavesignalenergytomeasurethequalityofthelasershockpeeningbyestablishingthecorrespondencebetweentheacousticwavesignalenergyandthelaserpulseenergy.ThesurfaceresidualstressesofthesamplesaremeasuredbyX-raystressanalysisinstrumenttoverifythereliability.Theresultsshowthatboththesurfaceresidualstressandacousticwavesignalenergyareincreasedwiththelaserpulseenergy,andtheirgrowthtrendsareconsistent.Finally,theempiricalformulabetweenthesurfaceresidualstressandtheacousticwavesignalenergyisestablishedbythecubicequationfitting,whichwillprovideatheoreticalbasisforthereal-timeonlinedetectionoflasershockpeening.

简介：Thispaperpresentsafault-detectionmethodbasedonthephasespacereconstructionanddataminingapproachesforthecomplexelectronicsystem.TheapproachforthephasespacereconstructionofchaotictimeseriesisacombinationalgorithmofmultipleautocorrelationandΓ-test,bywhichthequasi-optimalembeddingdimensionandtimedelaycanbeobtained.Thedataminingalgorithm,whichcalculatestheradiusofgyrationofunit-masspointaroundthecentreofmassinthephasespace,candistinguishthefaultparameterfromthechaotictimeseriesoutputbythetestedsystem.Theexperimentalresultsdepictthatthisfaultdetectionmethodcancorrectlydetectthefaultphenomenaofelectronicsystem.

简介：动态察觉基于光学传感器和变化雷达是一个新方法检测飞行帮助灯的发光紧张。光学传感器能得到每盏灯的照明信息，变化雷达得到距离信息，然后数据合并技术被用来计算每盏灯的发光紧张。修改这个动态察觉系统的错误的一个方法被介绍。它由基于光学传感器使用山峰价值察觉估计每盏灯的精确位置避免累积错误和测量搬运人的旅行错误，然后修改光的纵向距离信息和横向的位置信息。察觉和变化系统的表演被一些实验验证并且出现在图画。

简介：Compressivesensingisarevolutionaryideaproposedrecentlytoachievemuchlowersamplingrateforsignals.Intheimageapplicationwithlimitedresourcesthecameradatacanbestoredandprocessedincompressedform.Analgorithmformovingobjectandregiondetectioninvideousingacompressivesamplingisdeveloped.Thealgorithmestimatesmotioninformationofthemovingobjectandregionsinthevideofromthecompressivemeasurementsofthecurrentimageandbackgroundscene.Thealgorithmdoesnotperforminversecompressiveoperationtoobtaintheactualpixelsofthecurrentimagenortheestimatedbackground.Thisleadstoacomputationallyefficientmethodandasystemcomparedwiththeexistingmotionestimationmethods.Theexperimentalresultsshowthatthesamplingratecanreduceto25%withoutsacrificingperformance.

简介：Asimpleinstrumentforthereal-timemeasurementofalgaeconcentrationandmappingdescribed.Theinstrumentusesapulsedshortarcxenonflashlampastheexcitedlightsources.Boththeexcitinglightandthefluorescencefromalgaechlorophyllaretransmittedalongafiberbundle.Themeasurementsensivitivityisanalyzedandtheexperimentresultisgiven.Theinstrumentispracticaltoin-situmeasurementatsea.

简介：Visualfiredetectiontechnologiescandetectfireandalarmwarningsearlierthanconventionalfiredetectors.Thisstudyproposesaneffectivevisualfiredetectionmethodthatcombinesthestatisticalfirecolormodelandsequentialpatternminingtechnologytodetectfireinanimage.Furthermore,theproposedmethodalsosupportsreal-timefiredetectionbyintegratingadaptivebackgroundsubtractiontechnologies.Experimentalresultsshowthattheproposedmethodcaneffectivelydetectfireintestimagesandvideos.ThedetectionaccuracyoftheproposedhybridmethodisbetterthanthatofCelik’smethod.

简介：Inmausoleummurals,existingbubblesareonekindofthemostharmfuldefectsfortherepairandprotectionofrelics.Forthisreason,itisnecessarytodetectbubbles,especiallytheoneswithsmallsize.Amethodtodetectthesmallbubbleswithenhancedterahertz(THz)imagesisproposed.Tosimulatethebubblesinthemausoleummurals,circulargrooveshavebeenhiddenintheplasterandthenmeasuredbytheTHzreflectedtimedomainspectroscopyimagingsystem.Toobservethesmallbubblesinmurals,acomprehensiveenhancementalgorithmisadoptedtoprocesstheobtainedTHzimages.Withtheenhancedmethod,thecirculargroovesinthemuralscanbeobservedclearly,evenforthecirculargroovewithadiameterof1.5mm.Theresultsindicatethattheproposedcomprehensivemethodcanbeusedtodetectthetinydefectsofmurals.

简介：Whentheclassicalconstantfalse-alarmrate(CFAR)combinedwithfuzzyC-means(FCM)algorithmisappliedtotargetdetectioninsyntheticapertureradar(SAR)imageswithcomplexbackground,CFARrequiresblock-by-blockestimationofcluttermodelsandFCMclusteringconvergestolocaloptimum.Toaddresstheseproblems,thispaperpro-posesanewdetectionalgorithm:knowledge-basedcombinedwithimprovedgeneticalgorithm-fuzzyC-means(GA-FCM)algorithm.Firstly,thealgorithmtakestargetregion’smaximumandaverageintensity,area,lengthoflongaxisandlong-to-shortaxisratiooftheexternalellipseasfactorswhichinfluencethetargetappearingprobability.Theknowledge-baseddetectionalgorithmcanproducepreprocessresultswithouttheneedofestimationofcluttermodelsasCFARdoes.AfterwardtheGA-FCMalgorithmisimprovedtoclusterpre-processresults.IthasadvantagesofincorporatingglobaloptimizingabilityofGAandlocaloptimizingabilityofFCM,whichwillfurthereliminatefalsealarmsandgetbetterresults.TheeffectivenessoftheproposedtechniqueisexperimentallyvalidatedwithrealSARimages.

简介：Anoveladaptiveswitchingfilter(ASF)basedondirectionaldetectionisproposedfordenoisingtheimagesthatarehighlycorruptedbyimpulsenoise.Theproposedalgorithmemploysanefficientnoisedetectionmechanism.Itfirstemploysanefficientmethodtoestimatethedifferencesbetweenthecurrentpixelanditsneighborsalignedwith28directions.Thecurrentnoisepixelisreplacedbyamedianorameanvaluewithinanadaptivefilterwindowwithrespecttodifferentnoisedensities.Experimentalresultsshowthattheproposedapproachcannotonlyachieveverylowmiss-detectionratioandfalse-alarmratioevenuptohighnoisecorruption,butalsopreservethedetailedinformationofanimageverywell.

简介：Inordertoovercomethedisadvantagesoflowaccuracyrate,highcomplexityandpoorrobustnesstoimagenoiseinmanytraditionalalgorithmsofcloudimagedetection,thispaperproposedanovelalgorithmonthebasisofMarkovRandomField(MRF)modeling.Thispaperfirstdefinedalgorithmmodelandderivedthecorefactorsaffectingtheperformanceofthealgorithm,andthen,thesolvingofthisalgorithmwasobtainedbytheuseofBeliefPropagation(BP)algorithmandIteratedConditionalModes(ICM)algorithm.Finally,experimentsindicatethatthisalgorithmforthecloudimagedetectionhashigheraverageaccuracyratewhichisabout98.76%andtheaverageresultcanalsoreach96.92%fordifferenttypeofimagenoise.

简介：Basedonthewhiteningpropertyofwavelettransformationfor1/fnoise,thispaperaddressestheproblemofdetectingdeterministicsignalsinthepresenceof1/ffractalnoise.Thetransferfunctionofwhiteningfilterisprovidedaswellastheconditionforwhitening.ThereceiverstructurebasedonKarhunen-Loeveexpansionandthedecisionrulearealsogiven.Finallyperformanceofthedetectorisanalyzed.

简介：Thetructure,equivalentcircuit,noisesoucesofsiliconphotodiodeareanalyzed.Inordertoimprovethemeasuringlinearity,wemustchoosethesiliconphotodiodewithalargeRd,smallRsandI0andunderanoperationstateofoutputshort-circuit.Wemustlettheoperationamplifierworkinthecurrent-voltagetransferform.Alsoweanalyzedtheeffectsoftheinputnoisevoltage,theinputnoisecurrent,theinputoffsetvoltage,theinputoffsetcurrentoftheoperationamplifierandthenoisesofthesiliconphotodiodeonthecombinedcircuitoftheoperationamplifierwiththesiliconphotodiode.Consideringthesefactors,wecandesignthedetectivecircuitwithhighresponse,sensitivity,stability,linearityandSNR.

简介：FractionalBrownianmotion,continuouseverywhereanddifferentiablenowhere,offersaconvenientmodelingforirregularnonstationarystochasticprocesseswithlong-termdependenciesandpowerlawbehaviorofspectrumoverwiderangesoffrequencies.Itshowshighcorrelationatcoasescaleandvariesslightlyatfinescale,whichissuitableforandsuccessfulindescribingandmodelingnaturalscenes.Ontheotherhand,man-madeobjectscanbeconstructivelywelldescribedbyusingasetofregularsimpleshapeprimitivessuchasline,cylinder,etc.andarefreeoffractal.Basedonthedifference,weprovideamethodtodiscriminateman-madeobjectsfromnaturalscenes.Experimentsareusedtodemonstratedthegoodefficiencyofthedevelopedtechnique.