简介:Differentmodalitiesinbiomedicalimages,likeCT,MRIandPETscanners,providedetailedcross-sectionalviewsofhumananatomy.Thispaperintroducesthree-dimensionalbrainreconstructionbasedonCTslices.Itcontainsfiltering,fuzzysegmentation,matchingmethodofcontours,cellarraystructureandimageanimation.Experimentalresultshaveshownitsvalidity.TheinnovationismatchingmethodofcontoursandfuzzysegmentationalgorithmofCTslices.
简介:Thispaperproposesanovelexemplar-basedmethodforreducingnoiseincomputedtomography(CT)images.Intheproposedmethod,denoisingisperformedoneachblockwiththehelpofagivendatabaseofstandardimageblocks.Foreachnoisyblock,itsdenoisedversionisthebestsparsepositivelinearcombinationoftheblocksinthedatabase.Weformulatetheproblemasaconstrainedoptimizationproblemsuchthatthesolutionisthedenoisedblock.Experimentalresultsdemonstratethegoodperformanceoftheproposedmethodovercurrentstate-of-the-artdenoisingmethods,intermsofbothobjectiveandsubjectiveevaluations.
简介:在卫星收发系统中,圆极化天线是一种重要的器件,负责信号的接收和发送。而径向线螺旋天线是一种重要的圆极化天线,但为实现圆极化性能,天线高度需达到0.15λ。通过引入主径向线和副径向线之间的耦合,减小了天线的高度,从而实现了低剖面的径向线螺旋天线。通过在馈电结构中引入贴片电容,从而改善了天线的阻抗匹配性能。所提出的径向线螺旋天线的高度为0.0525λ,仅为传统径向线螺旋天线高度的34%。为验证理论预期的可实现性,设计了基板为FR4、中心频率在1.54GHz的低剖面径向线螺旋天线。实验结果表明,该天线的实测10-dB匹配带宽和3-dB轴比带宽分别为900MHz和27MHz,实测增益在2.9dBi,能够满足卫星接收天线的收发要求。