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简介：InordertoexplorethecorrelationbetweentheadjacentsegmentsofalongtermEEG,animprovedprincipalcomponentanalysis(PCA)methodbasedonmutualinformationalgorithmisproposed.Aone-dimensionEEGtimeseriesisdividedequallyintomanysegments,sothateachsegmentcanberegardedasanindependentvariablesandmulti-segmentedEEGcanbeexpressedasadatamatrix.Then,wesubstitutemutualinformationmatrixforcovariancematrixinPCAandconducttherelevanceanalysisofsegmentedEEG.Theexperimentalresultsshowthatthecontributionrateoffirstprincipalcomponent(FPC)ofsegmentedEEGismorelargerthanothers,whichcaneffectivelyreflectthedifferenceofepilepticEEGandnormalEEGwiththechangeofsegmentnumber.Inaddition,theevolutionofFPCconducetoidentifythetime-segmentlocationsofabnormaldynamicprocessesofbrainactivities,theseconclusionsarehelpfulfortheclinicalanalysisofEEG.

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简介：ThreedifferenttypesofVGOwereselectedandcutintovariousdistillatesbytrueboiling-pointdistillation(TBD),andthedistillateswerefurtherseparatedintodifferentcomponents(saturates,aromaticsandresins)viasolidphaseextraction(SPE).Thehydrocarboncomponentsinsaturatesandaromaticswerecharacterizedonthequasi-molecularlevelbyGC/MSandGC/TOFMS.CrackingreactionsofVGO,theirdistillates,andhydrocarboncomponents(saturatesandaromatics)wereperformedonanACE(modelAP)unit.Ninecorrelationparameters(mainlybasedonthepreviousassumptionofbasicstructureunits,BSU)whichcouldbetterreflectthestructuresandcompositionsofhydrocarbonswereputforwardbasedonthequasi-molecularlevelanalysisdata,andcorrelatedwithFCCproductdistributionbymulti-regressionmethod.Aseriesofcorrelationformulaswereobtained.TheformulaswerefurtherverifiedbycomparingexperimentalandcalculatedFCCyieldsemanatedfromtwootherVGOfeedstocks.

简介：Themodeswitchingbetweenspatialmultiplexing(SM)andspace-timeblockcode(STBC)diversityisinvestigatedforthemultiple-inputmultiple-output(MIMO)automaticrepeatrequest(ARQ)system.Fiveimportantpracticalfactorsareconsideredintheproposedswitchingscheme:transmitcorrelation,ARQtechnique,packetlossprobability(PLP)constraint,discreteratetransmission(DRT)andchannelcoding.Underthespatiallycorrelatedchannel,thedistributionsofthepostsignal-to-interference-plusnoiseratio(SINR)fortheSMmodeandtheSTBCmodeareobtainedbyusingGammaapproximations.Thenthispaperderivestheclosed-formexpressionsofthePLPandthethroughputfordifferentmodeswhentheARQtechniqueisemployed,basedonwhichthemodeswitchingalgorithmisproposedtoimprovethespectralefficency.Inthesimulation,thecorrectionoftheexpressionsisfirstverified.Then,thesignificantgainobservedbytheproposedalgorithmispresented.Sincetheswitchingpointisthekeyparametertoimplementthemodeswitching,thispaperalsoshowshowtheswitchingpointisaffectedbythepracticalfactorsconsidered.

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简介：Objectives:Polymerizationshrinkageofdentalcompositesremainsamajorconcerninrestorativedentistrybecauseitcanleadtomicro-crackingofthetoothanddebondingatthetooth-restorationinterface.Theaimofthisstudywastomeasurethefull-fieldpolymerizationshrinkageofdentalcompositesusingtheopticaldigitalimagecorrelation(DIC)methodandtoevaluatehowthemeasurementisinfluencedbythefactorsinexperimentsetupandimageanalysis.Methods:Fourcommercialdentalcomposites,PremiseDentine,Z100,Z250andTetricEvoCeram,weretested.Compositewasfirstplacedintoaslotmouldtoformabarspecimenwithrectangular-sectionof4mmmm,followedbythesurfacepaintingtocreateirregularspeckles.Curingwasthenappliedatoneendofthespecimenwhiletheotherpartwerecoveredagainstcuringlightforsimulatingtheclinicalcuringconditionofcompositeindentalcavity.Thepaintedsurfacewasrecordedbyacharge-coupleddevice(CCD)camerabeforeandaftercuring.Subsequently,thevolumetricshrinkageofthespecimenwascalculatedwithspecialistDICsoftwarebasedonimagecrosscorrelation.Inaddition,afewfactorsthatmayinfluencethemeasuringaccuracy,includingthesubsetwindowsize,specklesize,illuminationlightandspecimenlength,werealsoevaluated.Results:ThevolumetricshrinkageofthespecimengenerallydecreaseswithincreasingdistancefromtheirradiatedsurfacewithaconspicuousexceptionbeingthecompositePremiseDentineasitsmaximumshrinkageoccurredatasubsurfacedistanceofabout1mminsteadoftheirradiatedsurface.Z100hadthegreatestmaximumshrinkagestrain,followedbyZ250,TetricEvoCeramandthenPremiseDentine.Largersubsetwindowsizemadetheshrinkagestraincontoursmoother.Butthecostwasthatsomedetailsintheheterogeneityofthematerialwerelost.Verysmallsubsetwindowsizeresultedinalotofnoiseinthedata,makingitdifficulttodiscernthegeneralpatterninthestraindistribution.Speckle

简介：Abi-caponbeamforming(BCB)algorithmformulti-inputmulti-output(MIMO)radarisdevelopedonthebasisofcorrelationdomain.Byvectorizingtheechomatrixanditstranspose,theconventionalcaponcostfunctionistransformedintobi-caponquadraticfunctions.Bycalculatingtwolowerdimensionalweightvectorswithsub-matricesofthecorrelationmatrix,BCBcansignificantlydecreasethecomputationalcomplexityandtherequirementoftrainingsamples.Inthepresenceofshortdatarecords,BCBcanachievebetterinterferencesuppressionperformancethanfullyadaptivecaponalgorithm.Simulationresultsarepresentedtodemonstratetheeffectivenessoftheproposedmethod.

简介：Thecorrelationofthescaledenergy,e?=Es/M0,versusearthquakemagnitude,Ms,isstudiedbasedontwomodels:(1)Model1basedontheuseofthetimefunctionoftheaveragedisplacements,withax-2sourcespectrum,acrossafaultplane;and(2)Model2basedontheuseofthetimefunctionoftheaveragedisplacements,withax-3sourcespectrum,acrossafaultplane.Forthesecondmodel,therearetwocases:(a)Ass*T,wheresistherisetimeandTtherupturetime,lg(e?)*-Ms;and(b)AssT,lg(e?)*-(1/2)Ms.Thesecondmodelleadstoanegativevalueofe?.ThismeansthatModel2cannotworkforstudyingthepresentproblem.TheresultsobtainedfromModel1suggestthatthesourcemodelisafactor,yetnotauniqueone,incontrollingthecorrelationofe?versusMs.

简介：OBJECTIVE:ToevaluatetheassociationofX-raycross-complementinggroup1(XRCC1)Arg399Gln,Arg194TrpandArg280Hispolymorphismswiththeriskofglioma.DATASOURCES:AsystematicliteraturesearchofpaperspublishedfromJanuary2000toAugust2012inPubMed,Embase,ChinaNationalKnowledgeInfrastructuredatabase,andWanfangdatabasewasperformed.Thekeywordsusedwere"glioma","polymorphism",and"XRCC1orX-rayrepaircross-complementinggroup1".Referencescitedintheretrievedarticleswerescreenedmanuallytoidentifyadditionaleligiblestudies.STUDYSELECTION:Studieswereidentifiedaccordingtothefollowinginclusioncriteria:case-controldesignwasbasedonunrelatedindividuals;andgenotypefrequencywasavailabletoestimateanoddsratio(OR)and95%confidenceinterval(CI).Meta-analysiswasperformedfortheselectedstudiesafterstrictscreening.Dominantandrecessivegeneticmodelswereusedandtherelationshipbetweenhomozygousmutantgenotypefrequenciesandmutantgenefrequencyandgliomaincidencewasinvestigated.WechosethefixedorrandomeffectmodelaccordingtotheheterogeneitytocalculateORand95%CI,andsensitivityanalyseswereconducted.PublicationbiaswasexaminedusingtheinvertedfunnelplotandtheEgger’stestusingStata12.0software.MAINOUTCOMEMEASURES:AssociationofXRCC1Arg399Gln,Arg194Trp,andArg280Hispolymorphismswiththeriskofglioma,andsubgroupanalyseswereperformedaccordingtodifferentethnicitiesofthesubjects.RESULTS:Twelvearticleswereincludedinthemeta-analysis.ElevenofthearticleswereconcernedwiththeArg399Glnpolymorphismandgliomaonsetrisk.Significantlyincreasedgliomariskswerefoundonlyinthedominantmodel(Gln/Gln+Gln/ArgversusArg/Arg:OR=1.26,95%CI=1.03-1.54,P=0.02).Inthesubgroupanalysisbyethnicity,significantlyincreasedriskwasfoundinAsiansubjectsintherecessive(OR=1.46,95%CI=1.04-2.45,P=0.03)anddominantmodels(OR=1.40,95%CI=1.10-1.78,P=0.007),andhomozygotecontrast(OR=1.69,95%CI=1.17-2.45,P=0.005),bu