简介:Thispaperdealswiththebifurcationproblemsofmultiparameterandmultibranchandtheirapproximations.Itderivesgeneralapproximationresultsofsolutionbranchesintheneighbourhoodofasingular(limit,turningormultibranch)point,andshowsthatturningandmultibranchpointsarebifurcationpoints.TheabstracttheoriesareappliedtoamixedfiniteelementapproximationofstationaryNavier-Stokesequation.
简介:AnSMIBmodelinthepowersystems,especiallythatconceringtheeffectsofhardlimitsonbifurcations,chaosandstabilityisstudied.Parameterconditionsforbifurcationsandchaosintheabsenceofhardlimitsarecomparedwiththoseinthepresenceofhardlimits.Ithasbeenprovedthathardlimitscanaffectsystemstability.Wefindthat(1)hardlimitscanchangeunstableequilibriumintostableone;(2)hardlimitscanchangestabilityoflimitcyclesinducedbyHopfbifurcation;(3)persistenceofhardlimitscanstabilizedivergenttrajectorytoastableequilibriumorlimitcycle;(4)HopfbifurcationoccursbeforeSNbifurcation,sothesystemcollapsecanbecontrolledbeforeHopfbifurcationoccurs.Wealsofindthatsuitablelimitingvaluesofhardlimitscanenlargethefeasibilityregion.Theseresultsarebasedontheoreticalanalysisandnumericalsimulations,suchasconditionforSNBandHopfbifurcation,bifurcationdiagram,trajectories,Lyapunovexponent,Floquetmultipliers,dimensionofattractorandsoon.
简介:Inthispaper,westudythelocalbifurcationofcriticalperiodsnearthenondegeneratecenter(theorigin)ofaclassofLiénardequationswithdegree2n,andprovethatatmost2n-2criticalperiods(takenintoaccountmultiplicity)canbeproducedfromaweakcenteroffiniteorder.Wealsoprovethatitcanhaveexactly2n-2criticalperiodsneartheorigin.
简介:Considerathree-dimensionalsystemhavinganinvariantsurface.Byusingbifurcationtechniquesandanalyzingthesolutionsofbifurcationequations,theauthorsstudythespacialbifurcationphenomenaofakmultipleclosedorbitintheinvariantsurface.Thesufficientconditionsoftheexistenceofmanyclosedorbitsbifurcatefromthekmultipleclosedorbitareobtained.
简介:Thispaperstudiesaclassofquarticsystemwhichismoregeneralandrealisticthanthequarticaccompanyingsystem.x′=-y+ex+lx~2+mxy+ny~2,y′=x(1-Ay)(1+Cy~2),(*)whereC>0.Sufficientconditionsareobtainedfortheuniquenessoflimitcycleofsystem(*)andsomemorein-depthconclusionsuchasHopfbifurcation.
简介:Inthispaper,thedynamicsofadelayedphytoplankton-zooplanktonmodelisconsidered.Takingthedelayduetothegestationofzooplanktonasparameter,wedescribethelocalHopfbifurcationbycentermanifoldtheoremandnormalform,thenwediscusstheglobalexistenceofperiodicsolution.Atlast,somesimulationsaregiventosupportourresult.
简介:Inthispaperthedynamicsofaweaklynonlinearsystemsubjectedtocombinedparametricandexternalexcitationarediscussed.TheexistenceoftransversalhomoclinicorbitsresultinginchaoticdynamicsandbifurcationareestablishedbyusingtheaveragingmethodandMelnikovmethod.Numericalsimulationsarealsoprovidedtodemonstratethetheoreticalanalysis.
简介:Inthispaper,athreedimensionalratio-dependentchemostatmodelwithperiod-icallypulsedinputisconsidered.ByusingthediscretedynamicalsystemdeterminedbythestroboscopicmapandFloquettheorem,anexactperiodicsolutionwithpositiveconcentrationsofsubstrateandpredatorintheabsenceofpreyisobtained.Whenβislessthansomecriti-calvaluetheboundaryperiodicsolution(x_s(t),0,z_s(t))islocallystable,andwhenβislargerthanthecriticalvaluethereareperiodicoscillationsinsubstrate,preyandpredator.IncreasingtheimpulsiveperiodT,thesystemundergoesaseriesofperiod-doublingbifurcationleadingtochaos,whichimpliesthatthedynamicalbehaviorsoftheperiodicallypulsedratio-dependentpredator-preyecosystemareverycomplex.
简介:Inthispaperthebifurcationsolutionbranchesofasemi-linearellipticproblemarestudied,anditsextendedsystemsareconstructed.
简介:Inthispaper,bifurcationofsmallamplitudelimitcyclesfromthedegenerateequilibriumofathree-dimensionalsystemisinvestigated.Firstly,themethodtocalculatethefocalvaluesatnilpotentcriticalpointoncentermanifoldisdiscussed.Thenanexampleisstudied,bycomputingthequasi-Lyapunovconstants,theexistenceofatleast4limitcyclesonthecentermanifoldisproved.Intermsofdegeneratesingularityinhigh-dimensionalsystems,ourworkisnew.