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  • 简介:ARONSON'SESTIMATESANDCONDITIONALDIFFUSIONPROCESSESQIANZHONGMIN(钱忠民)WEIGUOQIANG(魏国强)(DepartmentofMathematicalStatistics,EastCh...

  • 标签: DIFFUSION PROCESS Aronson’s ESTIMATE time reversed
  • 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.

  • 标签: 势函数 Conway多项式 颜色 链接 计算机代数 CPF
  • 简介:Inthispaper,thecycle’sstructureofembeddedgraphsinsurfacesarestudied.Accordingtothemethodoffundamentalcycles,thesetC(Ccontainsallshortest)isfound.AundirectedgraphGwithnverticeshasatmostO(n5)manyshortestcycles;IftheshortestcycleofGisoddcycle,thenGhasatmostO(n3)manyshortestcycles;IfGhasbeenembeddedinasurfaceSg(Ng,gisaconstant),thenithasatmostO(n3)shortestcycles,moreover,iftheshortestcycleofGisoddcycle,then,GhasatmostO(n2)manyshortestcycles.WecanfindacyclebaseofG,thenumberofoddcyclesofG,thenumberofevencyclesofG,thenumberofcontractiblecyclesofG,thenumberofnon-contractiblecyclesofG,arealldecided.IftheΠ-embeddedgraphGhasΠ-twosidedcycles,then,CcontainsashortestΠ-twosidedcycleofG,thereisapolynomiallyboundedalgorithmthatfindsashortestΠ-twosidedcycleofaΠ-embeddedgraphG,thenewandsimplesolutionsabouttheopenproblemofBojanMoharandCarstenThomassenareobtained.

  • 标签: 曲面嵌入 循环结构 基本周期 短周期 周期数 嵌入式
  • 简介:Byusingthefundamentalequationsofaxisymmetricshallowshellsofrevolution,thenonlinearbendingofashallowcorrugatedshellwithtaperunderarbitraryloadhasbeeninvestigated.ThenonlinearboundaryvalueproblemofthecorrugatedshellwasreducedtothenonlinearintegralequationsbyusingthemethodofGreen'sfunction.Tosolvetheintegralequations,expansionmethodwasusedtoobtainGreen'sfunction.ThentheintegralequationswerereducedtotheformwithdegeneratecorebyexpandingGreen'sfunctionasseriesofcharacteristicfunction.Therefore,theintegralequationsbecomenonlinearalgebraicequations.Newton'siterativemethodwasutilizedtosolvethenonlinearalgebraicequations.Toguaranteetheconvergenceoftheiterativemethod,deflectionatcenterwastakenascontrolparameter.Correspondingloadswereobtainedbyincreasingdeflectiononebyone.Asanumericalexample,elasticcharacteristicofshallowcorrugatedshellswithsphericaltaperwasstudied.Calculationresultsshowthatcharacteristicofcorrugatedshellschangesremarkably.Thesnappinginstabilitywhichisanalogoustoshallowsphericalshellsoccurswithincreasingloadifthetaperisrelativelylarge.Thesolutionisclosetotheexperimentalresults.

  • 标签: GREEN函数 非线性弯曲度 边界值 积分方程 弹性系数
  • 简介:AradialfunctioncanbeexpressedbyitsgeneratorthroughThepositivedefiniteofthefunctionplaysanimportantroteintheradialbasisinterpolation.WecannaturallyuseBochner’sTheoremtocheckifispositivedefinite.Thisrequireshoweveran-dhnensiotialFouriertransformationanditisnotveryeasytocalculate.Furthermoreinalotofcaseswewilluseforspacesofvariousdimensionstoo,thenforeveryfixednweneeddotheFouriertransformationoncetocheckifthefunctionispositivedefiniteinthen-di-mensionalspace.Thecompletelymonotonefunction:,whichisdiscussedin[4]ispositivedefiniteforarbitraryspacedimensions.Withthistechniquetvecanveryeasilycharacterizethepositivedefinite,ofaradialfunctionthroughitsgenerator.Unfortunatelythereisonlyaverysmallsubsetofradialfunctionwhichiscompletelymonotone.Thusthiscriterionexcludedalotofinterestingfunctionssuchascompactlysupportedradialfunction,whcihareveryusefulinapplic

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  • 简介:WeconductedtheresearchonthecalculationoftheJordannormalformofamatrixfrom1993to1998.Inthisperiod,weobtainedsometheoreticalresults,alsodevelopedandimplementedaseriesofalgorithmsforthetheoreticalresults.Nowthisresearchiscompletedtosomedegree.TheGolub-Wilkinson’sProblemComputingtheJordandecompositionofamatrix,introducedbyG.H.GolubandJ.

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  • 简介:Mardia(1970)definedameasureofmultivariatekurtosisandderiveditsasymptoticdistributionforsamplesfromamultivariatenormalpopulation.SomenewresultsonellipticaldistributionsareusedtoextendMardia’sresultstosamplesfromanellipticaldistribution.Theseresultsprovideamethodfortestinghypothesesonthekurtosisparameterofellipticaldistributions.AnappendixprovidesextensionsofKendallandStuart’s(1977)standarderrorsofbivariatemomentstothethirdandfourthorder.

  • 标签: ELLIPTICAL MULTIVARIATE Kendall asymptotic HOUGH Stuart
  • 简介:ExplicitexpressionsofMori-Tanaka’stensorforatransverselyisotropicfiberreinforcedUDcompositearepresented.Closed-formformulaefortheeffectiveelasticpropertiesofthecompositeareobtained.Ina3Dsense,theresultingcompliancetensorofthecompositeissymmetric.Nevertheless,the2DcompliancetensorbasedonadeterioratedMori-Tanaka’stensorisnotsymmetric.Noristhecompliancetensordefineduponadeteriorated2DEshelby’stensor.Thein-planeeffectiveelasticpropertiesgivenbythosethreeapproachesaredifferent.AdetailedcomparisonbetweenthepredictedresultsobtainedfromthoseapproacheswithexperimentaldataavailableforanumberofUDcompositesismade.更多还原

  • 标签: 柔度张量 注记 复合材料 横观各向同性 弹性性质 显式表达
  • 简介:导出了迁移方程的扩散近似方程,说明了它的离散纵标方法在区间内和边界上都有扩散极限,它的解关于一致地收敛于迁移方程的解.其收敛性的证明是依据其渐近扩散展开式,在边界层上得到的误差估计逼近其离散纵标方法的解.

  • 标签: 迁移方程 扩散近似 离散纵标方法 边界层分析 误差估计
  • 简介:对于圆锥型和棱锥型Hamiltonian的Eikonal型方程,本文给出了一种几何方法,得出其初值问题解的表达式并且说明由此式给出的解为原初值问题的粘性解.首先用一个凸函数序列逼近Eikonal型方程中的Hamiltonian,再由Hopf-Lax公式给出方程序列的粘性解,最后证明了该粘性解序列会收敛到Eikonal方程的粘性解.

  • 标签: HAMILTON-JACOBI方程 Eikonal型方程 Hopf-Lax公式
  • 简介:复习目标了解有关方程方程组的概念;能正确、熟练地解一元一次方程、一次方程组和一元二次方程;掌握分式方程的解法并会验根;掌握由一个二元一次方程和一个二元二次方程组成的方程组的解法;掌握一元二次方程根的判别式及应用;能正确列出方程方程组解应用题.

  • 标签: 方程 方程组 不等式 不等式组 中考 数学