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24 个结果
  • 简介:Inthispaper,westudytheperturbationofcertainofcubicsystem.Byusingthemethodofmulti-parameterperturbationtheoryandqualitativeanalysis,weinferthatthesystemunderconsiderationcanhavefivelimitcycles.

  • 标签: 扰动 分叉 立方系统 极限循环 环论
  • 简介:我们与处理描述并且分析一个简单SIS模型。特别地,我们借助于asymptotically自治的系统的理论给完全质的分析。如果足够的接触率或能力是小的,向后的分叉发生,这被发现。在那里存在,也被发现双稳态地方性的equilibria。在导致疾病的死亡的情况中,向后的分叉也发生,这被显示出。而且,在一些条件,和潜水艇下面没有限制周期批评Hopf分叉发生在另外一个下面条件。

  • 标签: 优选模型 SIS模型 传染病模型 应用数学
  • 简介:Thispaperdealswiththebifurcationproblemsofmultiparameterandmultibranchandtheirapproximations.Itderivesgeneralapproximationresultsofsolutionbranchesintheneighbourhoodofasingular(limit,turningormultibranch)point,andshowsthatturningandmultibranchpointsarebifurcationpoints.TheabstracttheoriesareappliedtoamixedfiniteelementapproximationofstationaryNavier-Stokesequation.

  • 标签: BIFURCATION TURNING stationary STOKES BRANCHES NAVIER
  • 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.

  • 标签: SMIB 分枝 模糊 稳定性 可能性域 微分方程
  • 简介:Inthispaper,westudythelocalbifurcationofcriticalperiodsnearthenondegeneratecenter(theorigin)ofaclassofLiénardequationswithdegree2n,andprovethatatmost2n-2criticalperiods(takenintoaccountmultiplicity)canbeproducedfromaweakcenteroffiniteorder.Wealsoprovethatitcanhaveexactly2n-2criticalperiodsneartheorigin.

  • 标签: LIÉNARD方程 局部分岔 局部分歧 非退化 有限阶 多重性
  • 简介:ANEWDETECTINGMETHODFORCONDITIONSOFEXISTENCEOFHOPFBIFURCATIONSHENJIAQI(沈家骐);JINGZHUJUN(井竹君)(DepartmentofMathematics,ShandongUn...

  • 标签: HURWITZ DETERMINANT matrix theory detecting method
  • 简介:Considerathree-dimensionalsystemhavinganinvariantsurface.Byusingbifurcationtechniquesandanalyzingthesolutionsofbifurcationequations,theauthorsstudythespacialbifurcationphenomenaofakmultipleclosedorbitintheinvariantsurface.Thesufficientconditionsoftheexistenceofmanyclosedorbitsbifurcatefromthekmultipleclosedorbitareobtained.

  • 标签: 表面变化 闭合周期轨道 三维系统 分支方程 线性代数
  • 简介:在这篇论文,稳定性;有时间延期的小世界的网络的Hopf分叉被学习。由分析延期的变化,我们在马厩上获得几个足够的条件;不稳定的性质。当延期传递批评价值时,Hopf分叉可以出现。而且,方向;区分周期的答案的稳定性被正常形式理论调查;中心歧管减小。由数字模拟,最后,我们进一步在这篇论文说明定理的有效性。

  • 标签: HOPF分歧 时滞 小世界网络 网络理论
  • 简介:Thispaperstudiesaclassofquarticsystemwhichismoregeneralandrealisticthanthequarticaccompanyingsystem.x′=-y+ex+lx~2+mxy+ny~2,y′=x(1-Ay)(1+Cy~2),(*)whereC>0.Sufficientconditionsareobtainedfortheuniquenessoflimitcycleofsystem(*)andsomemorein-depthconclusionsuchasHopfbifurcation.

  • 标签: 极限环 唯一性 HOPF分歧 四次系统
  • 简介:Inthispaper,thedynamicsofadelayedphytoplankton-zooplanktonmodelisconsidered.Takingthedelayduetothegestationofzooplanktonasparameter,wedescribethelocalHopfbifurcationbycentermanifoldtheoremandnormalform,thenwediscusstheglobalexistenceofperiodicsolution.Atlast,somesimulationsaregiventosupportourresult.

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  • 简介:Inthispaperthedynamicsofaweaklynonlinearsystemsubjectedtocombinedparametricandexternalexcitationarediscussed.TheexistenceoftransversalhomoclinicorbitsresultinginchaoticdynamicsandbifurcationareestablishedbyusingtheaveragingmethodandMelnikovmethod.Numericalsimulationsarealsoprovidedtodemonstratethetheoreticalanalysis.

  • 标签: Bifurcation chaos TRANSVERSAL HOMOCLINIC orbit
  • 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.

  • 标签: 生物模型 捕食者-被捕食者模型 脉冲输入 周期解 稳定性 分歧
  • 简介:Inthispaper,bifurcationofsmallamplitudelimitcyclesfromthedegenerateequilibriumofathree-dimensionalsystemisinvestigated.Firstly,themethodtocalculatethefocalvaluesatnilpotentcriticalpointoncentermanifoldisdiscussed.Thenanexampleisstudied,bycomputingthequasi-Lyapunovconstants,theexistenceofatleast4limitcyclesonthecentermanifoldisproved.Intermsofdegeneratesingularityinhigh-dimensionalsystems,ourworkisnew.

  • 标签: 极限环分支 三维系统 Lyapunov 复性 中心流形 高维系统