学科分类
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136 个结果
  • 简介:Basedondiscretewavelettransform,bothrelativewaveletenergy(RWE)andsegmentwaveletentropy(SWE)ofelectroencephalogram(EEG)aredefinedinthispaper.TheRWEprovidesquantitativelytheinformationabouttherelativeenergyassociatedwithdifferentfrequencybandspresentintheEEG.TheSWEcarriesinformationaboutthedegreeoforderordisorderassociatedwithdifferenttimesegmentofEEGevolution,whichcandeterminethetime-segmentlocalizationsofabnormaldynamicprocessesofbrainactivityduetothelocalizationcharacteristicsofthewavelettransform.TheexperimentalresultsshowthattheRWEandSWEaredifferentbetweenepilepticEEGsandnormalEEGs,whichdemonstratethattheRWEandtheSWEarehelpfultoanalyzethedynamicbehaviorofdifferentEEGs.

  • 标签: 脑电图 小波熵 离散小波变换 频谱 小波能量 活动异常
  • 简介:Lidarisaneffectivetoolforremotelymonitoringtargetorobject,butthelidarsignalisoftenaffectedbyvariousnoisesorinterferences.Therefore,detectingtheweaksignalsburiedinnoisesisafundamentalandimportantprobleminthelidarsystems.Inthispaper,aneffectivenoisereductionmethodcombiningwaveletimprovedthresholdwithwaveletdomainspatialfiltrationispresentedtodenoisepulselidarsignalandisinvestigatedbydetectingthesimulatingpulselidarsignalsinnoise.Thesimulationresultsshowthatthismethodcaneffectivelyidentifytheedgeofsignalanddetecttheweaklidarsignalburiedinnoises.

  • 标签: 降噪 激光雷达 小波分析 空间滤波
  • 简介:Inthisworktwoaspectsoftheoryofframesarepresented:asidenecessaryconditiononirregularwaveletframesisobtained,anotherperturbationofwaveletandGaborframesisconsidered.Specifically,wepresenttheresultsobtainedonframestabilitywhenonedisturbsthemotherofwaveletframe,ortheparameterofdilatation,andinGaborframeswhenthegeneratingfunctionortheparameteroftranslationareperturbed.Inallcasesweworkwithoutdemandingcompactnessofthesupport,neitheronthegeneratingfunction,noronitsFouriertransform.

  • 标签: 不规则小波结构 结构稳定性 平移参数 扩张参数 傅立叶变换
  • 简介:这份报纸从与决定因素卤2的一个膨胀矩阵联系的框架multiresolution分析(FMRA)探讨小浪框架的构造。决定因素卤2的膨胀矩阵能根据不可分的类似作为六个班被分类。在这份报纸,为他们的四个班,从FMRA的小浪框架的构造被获得,并且,作为例子,香农类型小浪框架被构造,它在某感觉为他们的optimality有独立价值。关键词FMRA-FMRA小浪框架-不可分的类似先生(2000)题目分类42C40由训练北京(20051D0501522)的基础的优秀才能支持了

  • 标签: FMRA小波框架 积分相似性 多分辨率分析 膨胀矩阵
  • 简介:Thispaperpresentssomeresultsoftherelationbetweenwavelettransformandfractaltransform.Thewavelettransformoftheattractoroffractaltransformpossesestranslationalandscaleinvariance.Sowespeedthefractalimageencodingbytestingtheinvarianceofthewavelettransformappropriateforimageencoding.Theclassficationschemeofrangeblocksbywavelettransformisgiveninthispaper.

  • 标签: FRACTAL TRANSFORM WAVELET TRANSFORM CLASSIFICATION scheme.
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  • 简介:Wavelettransformisaparticularlyusefultooltocharacterizetran-sientphenomenasuchaswavebreaking.Inthispaper,weapplywavelettransformtothedetectionandquantificationofthebreakingwaves.Weuseanewmethodthatusesthelocalpropertiesofwavelettransformtodetectandquantifythebreak-ingwavesandgivesomenewbreakingcriteria.Bycomparingthismethodwiththeclassicmethod,wefindthatwavelettransformisveryeffectiveinthedetectionofbreakingwaves.Withwavelettransform,asetofmeasuredwindwavedataisinves-tigated.Theresultshaverevealedsomepreviouslyunknownphenomenaaboutwavebreaking.

  • 标签: WAVELET WAVE BREAKING CRITERIA
  • 简介:Inthispaper,alargeclassofndimensionalorthogonalandbiorthognalwaveletfilters(lowpassandhighpass)arepresentedinexplicitexpression.Wealsocharacterizeorthogonalfilterswithlinearphaseinthiscase.Someexamplesarealsogiven,includingnonseparableorhogonalandbiorthogonalfilterswithlinearphase.

  • 标签: 有限小波滤子 显式表示 正交滤子 线性相 双正交滤子
  • 简介:Thewavelettransformhasremarkableadvantagesandwideapplicationsindenoisingbecauseofitscharacteristicofgoodtime-frequency.Basedontheanalysisoftraditionalwaveletdenoisingmethods,whicharebasedonFouriertransform,animprovedmethodisproposed.ItovercomestheshortcomingsofthetraditionalFourierdenoisingmethod.Inthispaper,thedenoisingproceduresareintroducedrespectivelybasedonthewavelettransformandthemethodofconnectingthewaveletthresholdwiththewaveletbasisisadopted.ThroughMatlabsimulationandconcretedata,itarrivesattheconclusionthatthemethodofsignaldenoisingbasedonthewavelettransformisobviouslymoreeffectiveandbetterthanthetraditionalmethodbasedonFouriertransform.

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  • 简介:Inthispaper,weintroducematrix-valuedmultiresolutionanalysisandmatrix-valuedwaveletpackets.Aprocedurefortheconstructionoftheorthogonalmatrix-valuedwaveletpacketsispresented.Thepropertiesofthematrix-valuedwaveletpacketsareinvestigated.Inparticular,aneworthonormalbasisofL2(R,Cs×s)isobtainedfromthematrix-valuedwaveletpackets.

  • 标签: 矩阵 多分辨率 正交函数 微分方程
  • 简介:Astherearelotsofnon-linearsystemsintherealengineering,itisveryimportanttodomoreresearchesonthemodelingandpredictionofnon-linearsystems.Basedonthemulti-resolutionanalysis(MRA)ofwavelettheory,thispapercombinedthewavelettheorywithneuralnetworkandestablishedaMRAwaveletnetworkwiththescalingfunctionandwaveletfunctionasitsneurons.Fromtheanalysisinthefrequencydomain,theresultsindicatedthatMRAwaveletnetworkwasbetterthanotherwaveletnetworksintheabilityofapproachingtothesignals.AnessentialresearchwascarriedoutonmodelingandpredictionwithMRAwaveletnetworkinthenon-linearsystem.Usingthelengthwiseswaydatareceivedfromtheexperimentofshipmodel,amodelofofflinepredictionwasestablishedandwasappliedtotheshort-timepredictionofshipmotion.Thesimulationresultsindicatedthattheforecastingmodelimprovedthepredictionprecisioneffectively,lengthenedtheforecastingtimeandhadabetterpredictionresultsthanthatofARlinearmodel.TheresearchindicatesthatitisfeasibletousetheMRAwaveletnetworkintheshort-timepredictionofshipmotion.

  • 标签: 船舶动力学 非线性系统 MAR微波网络 短期预测 AR模型
  • 简介:Anewmethodofshort-termforecastingforwaterconsumptioninmunicipalsupplywaternetworksbasedonwavelettransformationisintroduced.Bywaveletdecomposingcommonlyusedinthesignalfield,waterconsumptionperhourisdecomposedintomanyseries.Trenditem,cycleitemandrandomitemareseparatedfromtheoriginaltimeseriesinthisway.Thenbyanalyzing,buildingamodel,forecastingeveryseriesandcomposingtheresults,theforecastingvalueoftheoriginalconsumptionisreceived.Simulationresultsshowthatthisforecastingmethodisfasterandmoreaccurate,ofwhichtheerrorislessthan20%,indicatingthatthewaveletanalyticalmethodispracticable.

  • 标签: 小波分析 短期预测 用水量 供水网 调度管理
  • 简介:Researchinterestinmulti-frameSuperresolutionhasrisensubstantiallyinrecentyears.ThispaperpresentsamodifiedProjectionOntoConvexSet(POCS)superresolutionmethodbasedonwavelettransform.Themethodanalyzestheimageformationmodelfromwaveletmultiresolutionanalysispointofviewanddefinesanclosedconvexsetanditscorrespondingprojectionbasedonwavelettransform.Aniterativeprocedureisutilizedtoreducetheestimatederrorsoftheresultimage,andthisguaranteestheestimatedimagetolayintheintersectionofdifferentconvexsets,thusproducesahighresolutionimagewithareducederror.Theeffectivenessofthealgorithmisdemonstratedbyexperimentalresults.

  • 标签: 超级分解 子波变换 计算方法 影像