简介:Inthispaper,weconstructandanalyseamortarfinitevolumemethodforthediscretizationforthebiharmonicprobleminR2.Thismethodisbasedonthemortar-typeAdininonconformingfiniteelementspaces.TheoptimalorderH2-seminormerrorestimatebetweentheexactsolutionandthemortarAdinifinitevolumesolutionofthebiharmonicequationisestablished.
简介:AmutuallyorthogonalsystemofrationalSomeapproximationresultsareestablishedfunctionsonthewholelineisintroduced.Asanexampleofapplications,amodifiedLegendrerationalspectralschemeisgivenfortheDiracequation.Itsnumericalsolutionkeepsthesameconservationasthegenuinesolution.Thisfeaturenotonlyleadstoreasonablenumericalsimulationofnonlinearwaves,butalsosimplifiestheanalysis.Theconvergenceoftheproposedschemeisproved.Numericalresultsdemonstratetheefficiencyofthisnewapproachandcoincidewiththeanalysiswell.
简介:ThispaperisconcernedwithnumericalmethodsforAmericanoptionpricing.Weemploynumericalanalysisandthenotionofviscositysolutiontoshowuniformconvergenceoftheexplicitdifferenceschemeandthebinomialtreemethod.Wealsoprovetheexistenceandconvergenceoftheoptimalexerciseboundariesintheaboveapproximn.tions.
简介:ImplicitRunge-Kuttamethodishighlyaccurateandstableforstiffinitialvalueproblem.ButtheiterationtechniqueusedtosolveimplicitRunge-Kuttamethodrequireslotsofcomputationalefforts.Inthispaper,weextendtheParallelDiagonalIteratedRungeKutta(PDIRK)methodstodelaydifferentialequations(DDEs).WegivetheconvergenceregionofPDIRKmethods,andanalyzethespeedofconvergenceinthreepartsfortheP-stabilityregionoftheRunge-Kuttacorrectormethod.Finally,weanalysisthespeed-upfactorthroughanumericalexperiment.TheresultsshowthatthePDIRKmethodstoDDEsareefficient.
简介:Klein-Gordon-Schroedinger(KGS)equationsareveryimportantinphysics.Somepapersstudiedtheirwell-posednessandnumericalsolution[1-4],andanotherworksinvestigatedtheexistenceofglobalattractorinR^nandΩ包含于R^n(n≤3)[5-6,11-12].Inthispaper,wediscussthedynamicalbehaviorwhenweapplyspectralmethodtofindnumericalapproximationforperiodicinitialvalueproblemofKGSequations.ItincludestheexistenceofapproximateattractorAN,theuppersemi-continuityonAwhichisaglobalattractorofinitialproblemandtheupperboundsofHausdorffandfractaldimensionsforAandAN,etc.
简介:Aderivativepatchinterpolatingrecoverytechniqueisanalyzedforthefiniteelementapproximationtothesecondorderellipticboundaryvalueproblemsintwodimensionalcase.Itisshownthattheconvergencerateoftherecoveredgradientadmitssuperconvergenceontherecoveredsubdomain,andistwoorderhigherthantheoptimalglobalconvergencerate(ultracovergence)ataninternalnodepointwhenevenorderfiniteelementspacesandlocaluniformmeshesareused.
简介:ThispaperpresentsthedualbasesforanewfamilyofgeneralizedBallcurveswithapositionparameterK,whichincludestheBeziercurve,generalizedSaid-Ballcurveandsomeintermediatecurves.Usingthedualbases,therelativeMarsdenidentity,conversionformulasofbasesandcontrolpointsofvariouscurvesareobtained.
简介:Thepurposeofthispaperistostudythecascadicmultigridmethodforthesecondorderellipticproblemswithcurvedboundaryintwo-dimensionwhicharediscretizedbytheisoparametricfiniteelementmethodwithnumericalintegration.WeshowthattheCCGmethodisaccuratewithoptimalcomplexityandtraditionalmultigridsmoother(likesymmetricGauss-Seidel,SSORordampedJacobiiteration)isaccuratewithsuboptimalcomplexity.
简介:Inthispaper,theapplicationofhomotopymethodstotheloadflowmulti-solutionproblemsofpowersystemsisintroduced.BythegeneralizedBernshteintheorem,thecombinatorialnumberC2n^misshowntobetheBKKboundofthenumberofisolatedsolutionsofthepolynomialsystemtransformedfromloadflowequationswithgenericallychosencoefficients.AsaresultofthegeneralBezoutnumber,thenumberofpathsbeingfollowedisreducedsignificantlyinthepracticalloadflowcomputation.Finally,thecompleteP-Vcuresareobtainedbytrackingtheloadflowwithhomotopymethods.
简介:Inthisarticleweconsiderthefullydiscretetwo-levelfiniteelementGalerkinmethodforthetwo-dimensionalnonstationaryincompressibleNavier-Stokesequations.ThismethodconsistsindealingwiththefullydiscretenonlinearNavier-StokesproblemonacoarsemeshwithwidthHandthefullydiscretelineargeneralizedStokesproblemonafinemeshwithwidthh<
简介:Inthisarticleweconsideratwo-levelfiniteelementGalerkinmethodusingmixedfiniteelementsforthetwo-dimensionalnonstationaryincompressibleNavier-Stokesequations.ThemethodyieldsaH^1-optimalvelocityapproximationandaL^2-optimalpressureapproximation.Thetwo-levelfiniteelementGalerkinmethodinvolvessolvingonesmall,nonlinearNavier-StokesproblemonthecoarsemeshwithmeshsizeH,onelinearStokesproblemonthefinemeshwithmeshsizeh<
简介:Atwo-gridmethodforthesteadypenalizedincompressibleNavier-Stokesequationsispresented.Convergenceresultsareproved.Ifh=O(H^3-s)andε=O(H^5-2s)(s=0(n=2);s=1/2(n=3)arechosen,theconvergenceorderofthistwo-gridmethodisthesameasthatoftheusualfiniteelementmethod.Numericalresultsshowthatthismethodisefficientandcansavealotofcomputationtime.
简介:Inthispaper,wediscusstheconvergenceoftheBroydenalgorithmswithrevisedsearchdirection.Undersomeinexactlinesearches,weprovethatthealgorithmsaregloballyconvergentforcontinuouslydifferentiablefunctionsandtherateoflocalconvergenceofthealgorithmsisone-stepsuperlinearandn-stepsecond-orderforuniformlyconvexobjectivefunctions.
简介:Inthispapertheleast-squaresmixedfiniteelementisconsideredforsolvingsecondorderellipticproblemsintwodimensionaldomains.Theprimarysolutionuandthefluxerareapproximatedusingfiniteelementspacesconsistingofpiecewisepolynomialsofdegreekandrrespectively.Basedoninterpolationoperatorsandanauxiliaryprojection,superconvergentH^1-errorestimatesofboththeprimarysolutionapproximationuhandthefluxapproximationσhareobtainedunderthestandardquasi-uniformassumptiononfiniteelementpartition.ThesuperconvergenceindicatesanaccuracyofO(h^r+2)fortheleast-squaresmixedfiniteelementapproximationifRaviart-ThomasorBrezzi-DouglasFortin-MarinielementsoforderrareemployedwithoptimalerrorestimateofO(h^r+l).
简介:Iterativetechniquesforsolvingoptimalcontrolsystemsgovernedbyparabolicvariationalinequalitiesarepresented.Thetechniquesweusearebasedonlinearfiniteelementsmethodtoapproximatethestateequationsandnonlinearconjugategradientmethodstosolvethediscreteoptimalcontrolproblem.Convergenceresultsandnumericalexperimentsarepresented.
简介:Somenonlinearapproximants,i.e.,exponential-suminterpolationwithequaldistanceoratorigin,(0,1)-type,(0,2)-typeand(1,2)-typefraction-sumapproximations,formatrixvaluedfunctionsareintroduced.Alltheseapproximationproblemsleadtoasameformsystemofnonlinearequations.Solvingmethodsforthenonlinearsystemarediscussed.Conclusionsonuniquenessandconvergenceoftheapproximantsforcertainclassoffunctionsaregiven.