简介:AimingtosolvethemisclassificationproblemsofunsupervisedpolarimetricWishartclassificationalgorithmbasedonFreemandecomposition,anunsupervisedPolarimetricSyntheticApertureRadar(SAR)Interferomery(PolInSAR)classificationalgorithmbasedonoptimalcoherencesetparametersisstudiedandproposed.ThisalgorithmusestheresultofFreemandecompositiontodividetheimageintothreebasiccategoriesincludingsurfacescattering,volumescattering,anddouble-bounce.Then,thePolInSARoptimalcoherencesetparametersareusedtofinelydivideeachofthethreebasiccategoriesinto9categories,andthewholeimageisdividedinto27categories.BecauseboththeFreemandecompositionresultandoptimalcoherencesetparametersindicatespecificscatteringcharacteristics,thewholeimageismergedinto16categoriesbasedonphysicalmeaning.Atlast,theWishartclusterisemployedtoobtainthefinalclassificationresult.Topreservethepurityofscatteringcharacteristics,pixelswithsimilarscatteringcharacteristicsarerestrictedtobeclassifiedwithotherpixels.Thefinalclassificationresultseffectivelyresolvethemisclassificationproblem,notonlythebuildingscanbeeffectivelydistinguishedfromvegetationinurbanareas,butalsotheroadiswelldistinguishedfromgrass.Inthispaper,theE-SARPolInSARdataofGermanAerospaceCenter(DLR),areusedtoverifytheeffectivenessofthealgorithm.
简介:Fieldcomputation,anemergingcomputationtechnique,hasinspiredpassionofintelligencescienceresearch.Anovelfieldcomputationmodelbasedonthemagneticfieldtheoryisconstructed.Theproposedmagneticfieldcomputation(MFC)modelconsistsofafieldsimulator,anon-derivativeoptimizationalgorithmandanauxiliarydataprocessingunit.ThemathematicalmodelisdeducedandprovedthattheMFCmodelisequivalenttoaquadraticdiscriminantfunction.Furthermore,thefiniteelementprototypeisderived,andthesimulatorisdeveloped,combiningwithparticleswarmoptimizerforthefieldconfiguration.Twobenchmarkclassificationexperimentsarestudiedinthenumericalexperiment,andonenotableadvantageisdemonstratedthatlesstrainingsamplesarerequiredandabettergeneralizationcanbeachieved.
简介:Inthispaper,wepresentasimplebutpowerfulensembleforrobusttextureclassification.Theproposedmethodusesasingletypeoffeaturedescriptor,i.e.scale-invariantfeaturetransform(SIFT),andinheritsthespiritofthespatialpyramidmatchingmodel(SPM).Inaflexiblewayofpartitioningtheoriginaltextureimages,ourapproachcanproducesufficientinformativelocalfeaturesandtherebyformareliablefeaturepondortrainanewclass-specificdictionary.Totakefulladvantageofthisfeaturepond,wedevelopagroup-collaborativelyrepresentation-basedstrategy(GCRS)forthefinalclassification.Itissolvedbythewell-knowngrouplasso.Butwegobeyondofthisandproposealocality-constraintmethodtospeedupthis,namedlocalconstraint-GCRS(LC-GCRS).Experimentalresultsonthreepublictexturedatasetsdemonstratetheproposedapproachachievescompetitiveoutcomesandevenoutperformsthestate-of-the-artmethods.Particularly,mostofmethodscannotworkwellwhenonlyafewsamplesofeachcategoryareavailablefortraining,butourapproachstillachievesveryhighclassificationaccuracy,e.g.anaverageaccuracyof92.1%fortheBrodatzdatasetwhenonlyoneimageisusedfortraining,significantlyhigherthananyothermethods.
简介:Objective:Toexploretherelationshipbetweenperoxisomeproliferatoractivatedreceptor-gamma(PPARγ)andperoxisomeproliferator-activatedreceptor-gammacoactivator-1(PGC-1)expressioningastriccarcinoma(GC),andanalyzetheircorrelationswithclinicopathologicalfeaturesandclinicaloutcomesofpatients.Methods:Thetwo-stepimmunohistochemicalmethodwasusedtodetecttheexpressionofPPARγandPGC-1in179casesofGC,and108casesofmatchednormalgastricmucosa.Besides,16casesoffreshGCspecimensandcorrespondingnormalgastricmucosaweredetectedforPGC-1expressionwithWesternblotting.Results:ThepositiveratesofPPARγandPGC-1expressionweresignificantlylowerinGC(54.75%,49.16%)thaninnormalgastricmucosa(70.37%,71.30%),respectively(P<0.05).ThedecreasedexpressionofPGC-1inGCwasconfirmedinourWesternblotanalysis(P=0.004).PPARγandPGC-1expressionswererelatedtoLauren’stypesofGC(P<0.05).PositivecorrelationwasfoundbetweenPPARγandPGC-1expressioninGC(rk=0.422,P<0.001).ThesurvivaltimeofPPARγnegativeandpositivepatientswas36.6±3.0vs.38.5±2.7months,andnostatisticaldifferencewasfoundbetweenthe5-yearsurvivalratesoftwogroups(34.4%vs.44.1%,P=0.522,log-ranktest);thesurvivaltimeofPGC-1negativeandpositivepatientswas36.2±2.8vs.39.9±2.9months,whilenostatisticaldifferencewasfoundbetweenthe5-yearsurvivalratesofthetwogroups(32.0%vs.48.2%,P=0.462,log-ranktest)Conclusions:DecreasedexpressionofPPARγandPGC-1inGCwasrelatedtotheLauren’sclassification.TheirexpressionsinGCwerepositivelycorrelated,indicatingthattheirfunctionsingastriccarcinogenesismaybecloselyrelated.