简介:Basedondiscretewavelettransform,bothrelativewaveletenergy(RWE)andsegmentwaveletentropy(SWE)ofelectroencephalogram(EEG)aredefinedinthispaper.TheRWEprovidesquantitativelytheinformationabouttherelativeenergyassociatedwithdifferentfrequencybandspresentintheEEG.TheSWEcarriesinformationaboutthedegreeoforderordisorderassociatedwithdifferenttimesegmentofEEGevolution,whichcandeterminethetime-segmentlocalizationsofabnormaldynamicprocessesofbrainactivityduetothelocalizationcharacteristicsofthewavelettransform.TheexperimentalresultsshowthattheRWEandSWEaredifferentbetweenepilepticEEGsandnormalEEGs,whichdemonstratethattheRWEandtheSWEarehelpfultoanalyzethedynamicbehaviorofdifferentEEGs.
简介:
简介:Lidarisaneffectivetoolforremotelymonitoringtargetorobject,butthelidarsignalisoftenaffectedbyvariousnoisesorinterferences.Therefore,detectingtheweaksignalsburiedinnoisesisafundamentalandimportantprobleminthelidarsystems.Inthispaper,aneffectivenoisereductionmethodcombiningwaveletimprovedthresholdwithwaveletdomainspatialfiltrationispresentedtodenoisepulselidarsignalandisinvestigatedbydetectingthesimulatingpulselidarsignalsinnoise.Thesimulationresultsshowthatthismethodcaneffectivelyidentifytheedgeofsignalanddetecttheweaklidarsignalburiedinnoises.
简介:Inthisworktwoaspectsoftheoryofframesarepresented:asidenecessaryconditiononirregularwaveletframesisobtained,anotherperturbationofwaveletandGaborframesisconsidered.Specifically,wepresenttheresultsobtainedonframestabilitywhenonedisturbsthemotherofwaveletframe,ortheparameterofdilatation,andinGaborframeswhenthegeneratingfunctionortheparameteroftranslationareperturbed.Inallcasesweworkwithoutdemandingcompactnessofthesupport,neitheronthegeneratingfunction,noronitsFouriertransform.
简介:Thispaperpresentssomeresultsoftherelationbetweenwavelettransformandfractaltransform.Thewavelettransformoftheattractoroffractaltransformpossesestranslationalandscaleinvariance.Sowespeedthefractalimageencodingbytestingtheinvarianceofthewavelettransformappropriateforimageencoding.Theclassficationschemeofrangeblocksbywavelettransformisgiveninthispaper.
简介:Wavelettransformisaparticularlyusefultooltocharacterizetran-sientphenomenasuchaswavebreaking.Inthispaper,weapplywavelettransformtothedetectionandquantificationofthebreakingwaves.Weuseanewmethodthatusesthelocalpropertiesofwavelettransformtodetectandquantifythebreak-ingwavesandgivesomenewbreakingcriteria.Bycomparingthismethodwiththeclassicmethod,wefindthatwavelettransformisveryeffectiveinthedetectionofbreakingwaves.Withwavelettransform,asetofmeasuredwindwavedataisinves-tigated.Theresultshaverevealedsomepreviouslyunknownphenomenaaboutwavebreaking.
简介:Inthispaper,alargeclassofndimensionalorthogonalandbiorthognalwaveletfilters(lowpassandhighpass)arepresentedinexplicitexpression.Wealsocharacterizeorthogonalfilterswithlinearphaseinthiscase.Someexamplesarealsogiven,includingnonseparableorhogonalandbiorthogonalfilterswithlinearphase.
简介:Thewavelettransformhasremarkableadvantagesandwideapplicationsindenoisingbecauseofitscharacteristicofgoodtime-frequency.Basedontheanalysisoftraditionalwaveletdenoisingmethods,whicharebasedonFouriertransform,animprovedmethodisproposed.ItovercomestheshortcomingsofthetraditionalFourierdenoisingmethod.Inthispaper,thedenoisingproceduresareintroducedrespectivelybasedonthewavelettransformandthemethodofconnectingthewaveletthresholdwiththewaveletbasisisadopted.ThroughMatlabsimulationandconcretedata,itarrivesattheconclusionthatthemethodofsignaldenoisingbasedonthewavelettransformisobviouslymoreeffectiveandbetterthanthetraditionalmethodbasedonFouriertransform.
简介:Inthispaper,weintroducematrix-valuedmultiresolutionanalysisandmatrix-valuedwaveletpackets.Aprocedurefortheconstructionoftheorthogonalmatrix-valuedwaveletpacketsispresented.Thepropertiesofthematrix-valuedwaveletpacketsareinvestigated.Inparticular,aneworthonormalbasisofL2(R,Cs×s)isobtainedfromthematrix-valuedwaveletpackets.
简介:Astherearelotsofnon-linearsystemsintherealengineering,itisveryimportanttodomoreresearchesonthemodelingandpredictionofnon-linearsystems.Basedonthemulti-resolutionanalysis(MRA)ofwavelettheory,thispapercombinedthewavelettheorywithneuralnetworkandestablishedaMRAwaveletnetworkwiththescalingfunctionandwaveletfunctionasitsneurons.Fromtheanalysisinthefrequencydomain,theresultsindicatedthatMRAwaveletnetworkwasbetterthanotherwaveletnetworksintheabilityofapproachingtothesignals.AnessentialresearchwascarriedoutonmodelingandpredictionwithMRAwaveletnetworkinthenon-linearsystem.Usingthelengthwiseswaydatareceivedfromtheexperimentofshipmodel,amodelofofflinepredictionwasestablishedandwasappliedtotheshort-timepredictionofshipmotion.Thesimulationresultsindicatedthattheforecastingmodelimprovedthepredictionprecisioneffectively,lengthenedtheforecastingtimeandhadabetterpredictionresultsthanthatofARlinearmodel.TheresearchindicatesthatitisfeasibletousetheMRAwaveletnetworkintheshort-timepredictionofshipmotion.
简介:Anewmethodofshort-termforecastingforwaterconsumptioninmunicipalsupplywaternetworksbasedonwavelettransformationisintroduced.Bywaveletdecomposingcommonlyusedinthesignalfield,waterconsumptionperhourisdecomposedintomanyseries.Trenditem,cycleitemandrandomitemareseparatedfromtheoriginaltimeseriesinthisway.Thenbyanalyzing,buildingamodel,forecastingeveryseriesandcomposingtheresults,theforecastingvalueoftheoriginalconsumptionisreceived.Simulationresultsshowthatthisforecastingmethodisfasterandmoreaccurate,ofwhichtheerrorislessthan20%,indicatingthatthewaveletanalyticalmethodispracticable.
简介:Researchinterestinmulti-frameSuperresolutionhasrisensubstantiallyinrecentyears.ThispaperpresentsamodifiedProjectionOntoConvexSet(POCS)superresolutionmethodbasedonwavelettransform.Themethodanalyzestheimageformationmodelfromwaveletmultiresolutionanalysispointofviewanddefinesanclosedconvexsetanditscorrespondingprojectionbasedonwavelettransform.Aniterativeprocedureisutilizedtoreducetheestimatederrorsoftheresultimage,andthisguaranteestheestimatedimagetolayintheintersectionofdifferentconvexsets,thusproducesahighresolutionimagewithareducederror.Theeffectivenessofthealgorithmisdemonstratedbyexperimentalresults.