简介:诺基亚手机第一代型号是:2110、8110、3810等,由于体积较大和功能较少已退出市场;第二代主要型号是:6110、5110、8810、6150等机型,也是由于体积较大功能较少市场上已较少使用;第三代常见机型为:8210、8250、8850、3310等,即DCT3(第三代数字核心技术)系列手机,由于功能较多,价格低廉,社会上拥有相当的数量;第四代机型以3510、6100、6310、6510、6610、7210、8310、8910等的DCT4(第四代数字核心技术)系列手机,它们功能齐全,外观新颖,有的具有彩屏、彩信、拍照和摄像等多种时尚功能。下面就谈一谈DCT3系列手机的维修:
简介:IntheH.263videocodecrelatedsystems,motionestimationandDiscreteCosineTransform(DCT)havethemostcomputationalrequirements.Inordertoreducecomplexityoftheencodertodedicatemoreresourcestootherfunctions,accordingtothestudyofexistingmethods,anImprovedAllZeroBlockFinding(IAZBF)methodbasedonthestatisticcharacteristicsofDCTcoefficientsisproposed.Comparedwithexistingmethods,IAZBFimprovesthedetectingefficiencybyabout50%withoutimportingtoomuchextracomputationrequirement.Beingcomputedwithadditionsandshiftsinsteadofcomplicatedmultiplications,IAZBFisoflowcomputationcomplexity,especiallyforlow-endprocessors.Inaddition,IAZBFupholdspicturefidelityandremainscompatiblewiththeH.263bitstreamstandard.
简介:BasedontheQuikSCATdata,thefeaturesofsurfacewinddistributionofthetyphoonVongfonglandfallprocessareanalyzed.WehavealsostudiedthevariancespectralconfigurationofthesurfacewindfieldusingDCT(DiscreteCosineTransform).Theconclusionsareasfollows:Thenear-surfacewindfieldishighlyasymmetric;thevariancecomponentsofasymmetricsurfacewindfielddependmainlyontheairflowdirectionofwavenumber1and2.Whenthetyphoonmoveswest,therearetwowavespectralcentersliningupinthezonaldirection,mainlytheairflowfromzonalwavenumber2andmeridionalwavenumber2;whenitmovesnorth,therearetwowavespectralcentersinameridionalarray,mainlytheairflowfromzonalwavenumber1andmeridionalwavenumber2.Theairflowforwavenumber1mainlycontributestothevarianceofthetangentialwindwhilethatforwavenumber2tothevarianceoftheradialwind.Theasymmetricaldistributionchangeswiththelarge-scaleenvironmentandself-rotatingcirculationaroundthetyphoon.Whenitapproachedland,theassociatedgaleappearsinfrontportionintheadvancingdirectionofthestorm.ItisineffectsimilartothemodelofChenLian-shoufortyphoon-relatedgales-NNWontheleftfrontportionandSEontherightfrontportion.