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简介：Evaluationofqualityofsingingisanissuesubjectivelyrealizedbytheexperts.Thispaperpresentstheresultsoftheanalysisofthevibratoparameterinthesinging.Thewell-knownfactistheexistenceofvibratoofsufficientqualityinthevoicesofprofessionalsingers.Theauthorsfocushereonthechoralvoicestoassessthequalityoftheirsingingfromthepointofviewofthevibratoparameter.Themethodpresentedhereisdevelopedtoevaluatethevibratowhilesingingunderconditionsclosetotherealones.Thestudywascarriedoutontherecordingsofthemembersofanacademicchoir.Asaresultoftestsitwasfoundthatnotallsingerspresentthesamequalityofvibratointermsofdeviationofvibratoconfidence(STDCV).

简介：Thispaperisasequeltoapreviouspaper(Yang,Y.andZhang,J.H.Existenceofsolutionsforsomefourth-orderboundaryvalueproblemswithparameters.NonlinearAnal.69(2),1364–1375(2008))inwhichthenontrivialsolutionstothefourthorderboundaryvalueproblemswerestudied.Inthecurrentworkwiththesameconditionsnearinfinitybutdifferentnearzero,thepositive,negative,andsign-changingsolutionsareobtainedbythecriticalpointtheory,retractingproperty,andinvariantsets.

简介：Themulti-parameterinversescatteringproblemofelasticwaveequationwithsinglefre-quencyisinvestigatedwithinBornapproximation.Byuseofawidebandmeasuringschemeinwhichbothtransmittersandreceiversscanoverthehalf-spacesurface,theformulaofthescatteringfieldofelasticwaveisderived.Fourtypesofmodeconversionofelasticwave(P→P,P→S,S→P,S→S)areseparatedfromthescatteringfield.Thesecomponentscontainsufficientinformationforustorecon-structtheconfigurationsofthedensityandLaméparametersofthemedium.Theinverseformulashavetheformoffilteredback-propagationasintheacousticdiffractiontomography.Computersimu-lationsarealsoobtained.

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简介：ThepurposeofthispaperistouseaveryrecentthreecriticalpointstheoremduetoBonannoandMaranotoestablishtheexistenceofatleastthreesolutionsforthequasilinearsecondorderdifferentialequationonacompactinterval[a,b]?R{-u’’=(λf(x,u)+g(u))h(u’),in(a,b),u(a)=u(b)=0underppropriatehypotheses.Weexhibittheexistenceofatleastthree(weak)solutionsand,andtheresultsareillustratedbyexamples.

简介：Thispaperinvestigatespersistenceoftransientdynamicsdependingonparametersinspatiallycoupledecologicalsystems.WeemphasisthatthepersistencetimecanbeobtainedbypopulationsofspeciesorLyapunovexponentsoftransientdynamics.Itisfoundthatextremesensitivedependenceofpersistenceonparametersoccurscommonlyinecologicalmodels.Anon-zerouncertaintyexponentisusedtocharacterizethehighsensitivityinareasonableparameterregion.Theresultofasmalluncertaintyexpone...

简介：TheExperimentalAdvanced.SuperconductingTokamak(EAST)isbeingbuiltinChinatoachievehighpowerandlongpulseoperationforstudiesofreactor-relevantissuesundersteady-stateconditions.AmajorconcernforEASTisthepowerhandlingcapabilityofthedivertortargetplates,whichisacriticalissueforfuturehigh-poweredsteady-statetokamaks,suchasITER.DetailedmodelingusingB2/EIRENEcodepackageandthemostrecentchemicalsputteringdatashowsthatthepresenceofstrongchemicalsputteringatthemainchamberwallleadstostrongcarbonradiationintheperipheryoftheconfinedplasma,significantlyreducingtheheatfluxestothetargetplatesandfacilitatingplasmadetachmentatalowerdensitydesiredforlowerhybridcurrentdriveinEAST,withonlyaslightincreaseinZ_(eff)attheedge.Thetargetheatloadcanbefurtherreducedbyoperatingwithadouble-nulldivertorconfiguration,whichalsoleadstoasignificantreductionintheedgeZ_(eff).However,thecodepredictsthatthedouble-nulloperationwouldresultinastrongdivertorasymmetryintargetpowerloading,favoringtheoutsidetargets.

简介：Inthepapertheproblemontheassignmentoftheboundsofdecreasingrateforatime-varyinglinearcontrolsystemisdiscussed.Thesufficientandnecessaryconditionforboundsofdecreasingrateofatime-varyinglinearsystemtobeassignedarbitrarilyispresented.Itispointedoutthatforanygivenrealnumbern,M,n

简介：Existingfarfieldexpressionsofsecondorderpotentialsarebynomeanscomplete.Hencetherehasbeennoexactfarfieldexpressionofsecondorderpotentials.InthispaperthefarfieldexpressionforΦd（2）ispurposelyavoidedindeducingtheformulaeofsecondorderforcesandaseriesoffunctionsΦdRnareused.Thefarfieldexpressionofisgiven,whichfor（x,U,z）∈Σ,φdRn（2）φd（2）.Usingthesepropertiesformulaeforcalculatingsecondorderdiffractionforcesareobtained.Tocalculatetheintegral∫∫1/gfΨdsitisdividedintotwoparts.Oneistheintegraloverafinitedomainandthefunctionundertheintegraliscontinuous,sotheusualapproximateintegrationformulaemaybeused.Theotheristheintegraloveraninfinitedomain.Usingthefarfieldexpressionoffirstorderpotentials,formulaeforcalculatingtheintegraltomeetgivenaccuraciesaregiven.Themooringforceinsurgedirectionisusedforcomparisonbetweennumericalpredictionsandexperimentalmeasurements.Thepredictedresultsarecheckedagainstthemeasuredvalueinaspeciallydesignedtest.Inthelowfrequencydomainofinterest,themooringforcesinsurge,forcalculatedandexperimentalspectraareingoodconsistencysolongasthedampingcoefficientsischoosenappropriately.

简介：Theresearchisabouttheeffectofalayerofvaryingdensityofsea-bottomsedimentsonspatialcorrelationofsea-bottombackscattering.Therelationshipbetweenscatteringcrosssectionandspatialcorrelationisthatbackscatteringcrosssectiondecreasesquicklyandthespatialcorrelationbecomesstrongerastheincidentangleincreases.Therefore,thedensitydepthprofileisintroducedintosea-bottomhigh-frequencybackscatteringechomodel,whichisusedtosimulatesea-bottombackscatteringandcalculatethefunctionofspatialcorrelation.Theinfluenceofthedensitygradientonspatialcorrelationofsea-bottombackscatteringisinvestigatedbyanalyzingtherelationsbetweenverticalgradientofdensityandthescatteringcrosssection.Ascanbeseenfromthesimulationresults,theimpactofthedensitygradientonthespatialcorrelationisfoundmoresignificant.Whilethedensitygradientincreases,thescatteringcross-sectionandtheradiusofthespatialcorrelationbroaden,thespatialcorrelationbecomesstronger.Atthesametime,thescatteringcross-sectiondecreasesmorequicklyastheincidentangleincreases.

简介：Thispaperstudiesscale-typestabilityforneuralnetworkswithunboundedtime-varyingdelaysandLipschitzcontinuousactivationfunctions.Severalsufficientconditionsfortheglobalexponentialstabilityandglobalasymptoticstabilityofsuchneuralnetworksontimescalesarederived.Thenewresultscanextendtheexistingrelevantstabilityresultsinthepreviousliteraturestocoversomegeneralneuralnetworks.

简介：Inthispaper,aclassoffuzzyBAMneuralnetworkswithtimevaryingdelaysisdiscussed.ByusingthepropertiesofM-matrix,LinearMatrixInequality(LMI)approachandgeneralLyapunov-Krasovskiifunctional,somenewsucientconditionsarederivedtoensuretheexistenceofperiodicsolutionsandtheglobalexponentialstabilityofthefuzzyBAMneuralnetworkswithtimevaryingdelays.TheseresultshaveimportantsignificanceinthedesignofglobalexponentialstableBAMnetworkswithdelays.Moreover,anexampleisgiventoillustratethattheconditionsoftheresultsinthepaperarefeasible.

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简介：与pointwise为连续时间的系统过滤的H的问题变化时间的延期在这份报纸被调查。由在Krein空间使用革新分析，为一个H过滤器的存在的一个必要、足够的条件在二个方法被导出：一个人是部分微分方程途径，其它是重新组织的革新分析途径。前者把一个答案给与边界条件以一个部分微分方程的答案过滤问题的建议H。以后把一个分析答案给以Riccati和矩阵的答案过滤问题的建议H微分方程。

简介：Thispaperisconcernedwiththeadaptivestabilizationproblemofuncertaininputdelayedsystems.Asolutiontothisproblemisgivenforaclassofuncertainnonlinearsystemswithtime-varyingdelaysinbothstateandinput.Anadaptiveasymptoticallystabilizingcontroller,whichcanguaranteethestabilityoftheclosed-loopsystemandtheconvergenceoftheoriginalsystemstate,isdesignedbymeansoftheLyapunov-Krasovskiifunctionalstabilitytheorycombinedwithlinearmatrixinequalities(LMIs)an...

简介：Thispaperstudiesestimationandserialcorrelationtestofasemiparametricvarying-coefficientpartiallylinearEVmodeloftheformY=Xτβ+Zτα(T)+ε,ξ=X+ηwiththeidentifyingconditionE[(ε,ητ)τ]=0,Cov[(ε,ητ)η]=σ2Ip+1.Theestimatorsofinterestedregressionparametersβ,andthemodelerrorvarianceσ2,aswellasthenonparametriccomponentsα(T),areconstructed.Undersomeregularconditions,weshowthattheestimatorsoftheunknownvectorβandtheunknownparameterσ2arestronglyconsistentandasymptoticallynormalandthattheestimatorofα(T)achievestheoptimalstrongconvergencerateoftheusualnonparametricregression.Basedontheseestimatorsandasymptoticproperties,weproposetheVN,pteststatisticandempiricallog-likelihoodratiostatisticfortestingserialcorrelationinthemodel.Theproposedstatisticsareshowntohaveasymptoticnormalorchi-squaredistributionsunderthenullhypothesisofnoserialcorrelation.Somesimulationstudiesareconductedtoillustratethefinitesampleperformanceoftheproposedtests.

简介：Inthispaper,westudyatypeofsusceptible-exposed-infected(SEI)epidemicmodelwithvaryingpopulationsizeandintroducetherandomperturbationoftheconstantcontactrateintotheSEIepidemicmodelduetotheuniversalexistenceoffluctuations.Undersomemoderateconditions,thedensityoftheexposedandtheinfectedindividualsexponentiallyapproacheszeroalmostsurelyarederived.Furthermore,thestochasticSEIepidemicmodeladmitsastationarydistributionaroundtheendemicequilibrium,andthesolutionisergodic.Somenumericalsimulationsarecarriedouttodemonstratetheefficiencyofthemainresults.

简介：Theproblemofdelay-dependentrobuststabilityforsystemswithtitne-varyingdelayhasbeenconsidered.ByusingtheS-procedureandthePark'sinequalityintherecentissue,adelay-dependentrobuststabilitycriterionwhichislessconservativethanthepreviousresultshasbeenderivedfortime-delaysystemswithtime-varyingstructureduncertainties.Thesameideahasalsobeeneasilyextendedtothesystemswithnonlinearperturbations.Numericalexamplesillustratedtheeffectivenessandtheimprovementoftheproposedapproach.

简介：ThisarticlefocusesonthestudyofallagestructuredSEIRSepidemicmodelwithavaccinationprogramwhenthetotalpopulationsizeisnotkeptatconstant.WefirstgivetheexplicitexpressionofthereproductionnumberR(ψ，^↑λ)inthepresenceofvaccine(^↑λistheexponentofgrowthoftotalpopulation),andshowthattheinfection-freesteadystateislh~earlystableifR(ψ，^↑λ)<1andunstableifR(ψ，^↑λ)>1,thenweapplythetheoreticalresultstovaccinationpoliciestodeterminetheoptimalageoragesatwhichanindividualshouldbevaccinated.Itisshownthattheoptilnalstrategycanbeeitherone-ortwo-agestrategies.