简介：摘要：s-function是一种描述动态系统的计算机语言，支持C语言编写，可以将已有的软件代码用文本方式输入，实现了代码移植和验证，非常适合复杂动态系统的数学描述，并且在仿真过程中可以对仿真进行更精确的控制。目前，实际风电变流器产品中，每台产品都需要在出厂时，都需要经过严格的测试，随着对产品不同功能的需求变化，采用的测试软件需要不断的优化和改进，所以，对软件算法的验证和升级需要仿真给予可靠的支持。本文利用在Simulink中搭建的三相全桥逆变器模型与S-Function编写的算法模块相结合，针对并网整流器运行工况进行软件仿真，简单、有效地验证了测试软件算法的正确性。

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简介：TheConwaypotentialfunction(CPF)forcoloredlinksisaconvenientversionofthemultivariableAlexander–Conwaypolynomial.WegiveaskeincharacterizationofCPF,muchsimplerthantheonebyMurakami.Inparticular,Conway’s"smoothingofcrossings"isnotintheaxioms.Theproofusesareductionschemeinatwistedgroup-algebraP_nB_n,whereB_nisabraidgroupandP_nisadomainofmulti-variablerationalfractions.Theproofdoesnotusecomputeralgebratools.Aninterestingby-productisacharacterizationoftheAlexander–Conwaypolynomialofknots.

简介：Byusingthefundamentalequationsofaxisymmetricshallowshellsofrevolution,thenonlinearbendingofashallowcorrugatedshellwithtaperunderarbitraryloadhasbeeninvestigated.ThenonlinearboundaryvalueproblemofthecorrugatedshellwasreducedtothenonlinearintegralequationsbyusingthemethodofGreen'sfunction.Tosolvetheintegralequations,expansionmethodwasusedtoobtainGreen'sfunction.ThentheintegralequationswerereducedtotheformwithdegeneratecorebyexpandingGreen'sfunctionasseriesofcharacteristicfunction.Therefore,theintegralequationsbecomenonlinearalgebraicequations.Newton'siterativemethodwasutilizedtosolvethenonlinearalgebraicequations.Toguaranteetheconvergenceoftheiterativemethod,deflectionatcenterwastakenascontrolparameter.Correspondingloadswereobtainedbyincreasingdeflectiononebyone.Asanumericalexample,elasticcharacteristicofshallowcorrugatedshellswithsphericaltaperwasstudied.Calculationresultsshowthatcharacteristicofcorrugatedshellschangesremarkably.Thesnappinginstabilitywhichisanalogoustoshallowsphericalshellsoccurswithincreasingloadifthetaperisrelativelylarge.Thesolutionisclosetotheexperimentalresults.

简介：AradialfunctioncanbeexpressedbyitsgeneratorthroughThepositivedefiniteofthefunctionplaysanimportantroteintheradialbasisinterpolation.WecannaturallyuseBochner’sTheoremtocheckifispositivedefinite.Thisrequireshoweveran-dhnensiotialFouriertransformationanditisnotveryeasytocalculate.Furthermoreinalotofcaseswewilluseforspacesofvariousdimensionstoo,thenforeveryfixednweneeddotheFouriertransformationoncetocheckifthefunctionispositivedefiniteinthen-di-mensionalspace.Thecompletelymonotonefunction:,whichisdiscussedin[4]ispositivedefiniteforarbitraryspacedimensions.Withthistechniquetvecanveryeasilycharacterizethepositivedefinite,ofaradialfunctionthroughitsgenerator.Unfortunatelythereisonlyaverysmallsubsetofradialfunctionwhichiscompletelymonotone.Thusthiscriterionexcludedalotofinterestingfunctionssuchascompactlysupportedradialfunction,whcihareveryusefulinapplic

简介：ConsiderthepiecewiselinearfiniteelementsubspaceSandparabolicsemidiscreteGreen’sfunctionofgradienttypeGh(t)∈Sk.Theasymptoticoptimalestimatedxdt

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简介：ThesolutionsofGreen'sfunctionaresignificantforsimplificationofproblemonatwo-phasesaturatedmedium.UsingtransformationofaxisymmetriccylindricalcoordinateandSommerfeld'sintegral,superpositionoftheinfluencefieldonafreesurface,authorsobtainedthesolutionsofatwo-phasesaturatedmediumsubjectedtoaconcentratedforceonthesemi-space.

简介：EstimatedGreen'sfunction(EGF)betweenstationshasbeenextractedfromambientseismicnoise,directsurfacewaveandcodawaves.Itisalsoconfirmedbylaboratoryexperimentsonultrasonicsandtheoreticalderivationsassumingdiffusivewavefield,equi-partitionofmodesorrandomsourcesonanenclosedsurface.Thismethodprovidesanewapproachtostudythecrustandmantlestructureatregionalscale,continentalscaleandglobalscale.Followingtheachievementswithseismometerrecords,therecordsofinfrasonicstation,hydrophoneandmicrophonewerealsousedtoobtaintheEGFsofdifferentwavefields.Sincesuperconductinggravimeterisabetterlongperiodinstrumentthanregularseismometer,EGFatlongerperiodisexpectedtobeobtainedwiththecrosscorrelationofgravitydata.Inthispaper,wewillshowtheEGFsextractedbycross-correlationsbetweenthesuperconductinggravimetersandtheseismometers.Boththetraveltimesanddispersioncurvesobtainedfromdifferentdatatypesareconsistent.Theresultshowsthatitispossibletoretrievethedeepstructurebythecrosscorrelationofgravitydata.

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简介：在这篇论文，基于高顺序的速度精力，集成和变化原则的定理，高顺序的哈密尔顿一般holonomic系统的原则被给。然后，三顺序的Lagrangian方程和四顺序的Lagrangian方程从高顺序的哈密尔顿的原则被获得。最后，哈密尔顿高顺序的Lagrangian功能的原则被给。

简介：Inthispaper,thefuzzyreliabilityfunctionZ=X+Yhasbeenderived.InthecaseofthatX,YsubjectstoMarshall-Olkinbivariateexponentialdistribution,assumingμ=μ1μ2.

简介：Inthisarticle,weanalyzethecharactersofSV-componentreceiverfunctionofteleseismicbodywavesanditsadvantagesinmappingtheS-wavevelocitystructureofcrustindetail.Similartoradialreceiverfunction,SV-componentreceiverfunctioncanbeobtainedbydirectlydeconvolvingtheP-componentfromtheSV-componentofteleseismicrecordings.OuranalysesindicatethatthechangeofamplitudeofSV-componentreceiverfunctionagainstthechangeofepicentraldistanceislessthanthatofradialreceiverfunction.Moreover,thewaveformofSV-componentreceiverfunctionissimplerthantheradialreceiverfunctionandgivesprominencetothePSconvertedphasesthatarethemostsensitivetotheshearwavevelocitystructureintheinversion.ThesynthetictestsshowthattheconvergenceofSV-componentreceiverfunctioninversionisfasterthanthatoftheradialreceiverfunctioninversion.Asanexample,weinvestigatetheS-wavevelocitystructurebeneathHIAstationbyusingtheSV-componentreceiverfunctioninversionmethod.

简介：IthasbeenfouryearssinceChinaEx-port&CreditInsuranceCorpo-rationwasfounded.Undertheconcernofrelevantdepartments,thesupportofalltheenterprises,thescaleofcreditinsuranceforexportsupporthasexpendedrapidly.In2005,ChinaExport&CreditInsuranceCorporationsupportedforeigneconomyandtradeexportUS$21.2billion.ThefunctionofExport&CreditInsuranceinthedevelopmentofourforeigneconomyandtradeexportisshowingup.Automobileexportisoneofthemainfieldsthattheexport&creditinsurancesupportingthemachineryandelectricityexport,andcarryingoutthestrategyofprosperingtradethroughscienceandtechnology.Astheundertakerofthemissionthatthestatesupportstheexport,ChinaExport&CreditInsuranceCorporationwillmakeeveryefforttosupporttheinternationaliza

简介：Inthispaper,atwo-scalefiniteelementapproachisproposedandanalyzedforapproximationsofGreen'sfunctioninthree-dimensions.Thisapproachisbasedonatwo-scalefiniteelementspacedefined,respectively,onthewholedomainwithsizeHandonsomesubdomaincontainingsingularpointswithsizeh(h<

简介：BasedonthesolutionsoftheGreen'sfunctionforasaturatedporousmediumobtainedbytheauthors,andusingtransformationofaxisymmetriccoordinates,Sommerfeldintegralsandsuperpositionoftheinfluencefieldonafreesurface,theauthorshaveobtaineddisplacementsolutionsofasaturatedporousmediumsubjectedtoatorsionalforceinahalf-space.Therelationshipcurvesofthedisplacementsolutionsandvariousparameters(permeability,frequency,etc.)underactionofaunitoftorquearealsogiveninthispaper.TheresultsareconsistentwithpreviousReissner'ssolutions,whereatwo-phasemediumdecaystoasingle-phasemedium.Thesolutionisusefulinsolvingrelevantdynamicproblemsofatwophasesaturatedmediuminengineering.

简介：Introduction,Theroleofleftventriculographyhasevolvedradicallyoverthelasthalf-century,buthasreceivedlittlenoticeintheacademicliterature.ThetechniqueandfrequencyofuseofleftventriculographyvaryacrossregionsoftheUnitedStates,institutions,andindividuals.

简介：ThisstudyproposesaGreen’sfunction,anessentialrepresentationofwater-saturatedgroundundermovingexcitation,tosimulategroundbornevibrationfromtrains.First,generalsolutionstothegoverningequationsofporoelasticmediumarederivedbymeansofintegraltransform.Secondly,thetransmissionandreflectionmatrixapproachisusedtoformulatetherelationshipbetweendisplacementandstressofthestratifiedground,whichresultsinthematrixoftheGreen’sfunction.ThentheGreen’sfunctioniscombinedintoatrain-track-groundmodel,andisverifiedbytypicalexamplesandafieldtest.Additionalsimulationsshowthatthecomputedgroundvibrationattenuatesfasterintheimmediatevicinityofthetrackthaninthesurroundingarea.Thewavelengthofwheel-railunevennesshasanotableeffectoncomputeddisplacementandporepressure.Thevariationofvibrationintensitywiththedepthofgroundissignificantlyinfluencedbythelayeringofthestratasoil.WhenthetrainspeedisequaltothevelocityoftheRayleighwave,theMachconeappearsinthesimulatedwavefield.TheproposedGreen’sfunctionisanappropriaterepresentationforalayeredgroundwithshallowgroundwatertable,andwillbehelpfultounderstandthedynamicresponsesofthegroundtocomplicatedmovingexcitation.

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