简介:Segmentingwholeheartfromcardiaccomputedtomography(CTimagescanprovideanimportantbasisfortheevaluationofcardiacfunctionandhelpimprovetheaccuracyofclinicaldiagnosis.Manualsegmentationisthemostaccuratemethodforcardiacsegmentation.Butitistimeconsumingandnotsufficientlyreproducible.However,cliniciansstillrelyonthismethodinpracticalapplications.Soafullyautomaticmethodisneededtoimprovethesegmentationefficiency.Thispapeproposesaregistration-basedautomaticapproachforthree-dimensional(3DsegmentationofcardiacCTimages.TheproposedmethodutilizesthesimilarityocardiacCTimagesbetweendifferentindividuals,andusesregistrationtoachievethesegmentation.Affinetransformationisfirstlyimplementedtoachieveglobalcoarseregistration.Then,cubicB-splinesareusedtorefinethelocaldetailsinlocallyaccurateregistration.Mutualinformation(Ml)isusedasthesimilaritymeasure,andadaptivestochasticgradientdescent(ASGD)astheoptimizationalgorithm.Oumethodisappliedtothedual-sourcecardiacCTimagestosegmentwholeheartExperimentalresultsshowthattheproposedmethodcanautomaticallysegmentwholeheartfromcardiacCTimages.
简介:摘 要 本文以教思考、教体验、教表达的“三教”理念,引领《3D One AI语音识别编程探究》教学课例,简述高中课堂信息技术教学培育学生核心素养的体会:激发学生兴趣,体验知识内涵;核心问题引领,促进学生编程中的计算思维;引导表达交流,提升社会信息责任,促进学生核心素养的培育。
简介:Ithasbeenshownthattheprogressinthedeterminationofmembraneproteinstructuregrowsexponentially,withapproximatelythesamegrowthrateasthatofthewater-solubleproteins.Inordertoinvestigatetheeffectofthis,ontheperformanceofpredictionalgorithmsforbothα-helicalandβ-barrelmembraneproteins,weconductedaprospectivestudybasedonhistoricalrecords.WetrainedseparatehiddenMarkovmodelswithdifferentsizedtrainingsetsandevaluatedtheirperformanceontopologypredictionforthetwoclassesoftransmembraneproteins.Weshowthattheexistingtop-scoringalgorithmsforpredictingthetransmembranesegmentsofα-helicalmembraneproteinsperformslightlybetterthanthatofβ-barreloutermembraneproteinsinallmeasuresofaccuracy.Withthesamerationale,ameta-analysisoftheperformanceofthesecondarystructurepredictionalgorithmsindicatesthatexistingalgorithmictechniquescannotbefurtherimprovedbyjustaddingmorenon-homologoussequencestothetrainingsets.Theupperlimitforsecondarystructurepredictionisestimatedtobenomorethan70%and80%ofcorrectlypredictedresiduesforsinglesequencebasedmethodsandmultiplesequencebasedones,respectively.Therefore,weshouldconcentrateoureffortsonutilizingnewtechniquesforthedevelopmentofevenbetterscoringpredictors.
简介:摘要:近年来,加工制造行业为应对新型产品面世以及产品加工制造压力,开始着重研究技术创新问题。基于FDM 技术的3D 打印机控制技术的出现,不仅可缓解企业竞争压力,同时简化制造技术,缩短开发周期,促使企业可高效完成产品制造。本文基于FDM 技术概述3D 打印机总体设计,并围绕基于外轮廓线的自适应分层算法、改进的分形扫描方法打印关键算法进行实例验证,对比打印质量以及打印时间,分析两种关键算法的可行性。
简介:In3Dmodelsretrieval,featuredescriptionandretrievalofnon-rigidmodelfacemorecomplexproblemsduetotheisometrytransformationofitself.Weintroducethehierarchicalcombinationmatchingintothefeaturecomparison,andbuildamapbetweenthedividedregionsoftwomodels,andthenachieveaccuratefeaturematchingbasedonpatch-by-patch,whichsuccessfullyintroducesthespatialinformationintofeaturematching.Verifiedbyexperiment,the3Dmodelretrievalmethodproposedinthispaperbasedonhierarchicalcombinationmatchingcanmakesuremoreaccuratefeaturematching,soastoenhancetheprecisionofretrieval.
简介:Isometric3Dshapepartialmatchinghasattractedagreatamountofinterest,withaplethoraofapplicationsrangingfromshaperecognitiontotexturemapping.Inthispaper,weproposeanovelisometric3DshapepartialmatchingalgorithmusingthegeodesicdiskLaplacespectrum(GD-DNA).Ittransformsthepartialmatchingproblemintothegeodesicdiskmatchingproblem.Firstly,thelargestenclosedgeodesicdiskextractedfromthepartialshapeismatchedwithgeodesicdisksfromthefullshapebytheLaplacespectrumofthegeodesicdisk.Secondly,GeneralizedMulti-DimensionalScalingalgorithm(GMDS)andEuclideanembeddingareconductedtoestablishfinalpointcorrespondencesbetweenthepartialandthefullshapeusingthematchedgeodesicdiskpair.TheproposedGD-DNAisdiscriminativeformatchinggeodesicdisks,anditcanwellsolvetheanchorpointselectionprobleminchallengingpartialshapematchingtasks.ExperimentalresultsontheShapeRetrievalContest2016(SHREC'16)benchmarkvalidatetheproposedmethod,andcomparisonswithisometricpartialmatchingalgorithmsintheliteratureshowthatourmethodhasahigherprecision.