简介:ThediscretedynamicsforcompetitionpopulationsofLotka-VolterratypemodeledasN1(t+1)=N1(t)exp[r1(1-N1-b12N2)],N2(t+1)=N2(t)exp[r2(1-N2-b21N1)]isconsideredinthepaper.Inthecaseofnon-persistencetheattractivebehaviorofmodelhasbeendiscussed.Especially,therearetwoattractivesetswhenbij>1,andtheattractivebehaviorsaremorecomplicatedthanthatofthecorrespondingcontinuousmodel.Theattractedregionsaregiven.Weprovethatthemodelisalsopersistentinthedegeneratecaseofbij=1.Inthepersistencecaseofbij<1,theexistenceanduniquenessfortwo-periodpointsofthemodelarestudiedatr1=r2.Theconditionforthemulti-pairoftwo-periodpointsisindicatedandtheirinfluencesonpopulationdynamicalbehaviorsareshown.
简介:非线性生态数学离散模型的持续生存性和全局稳定性等动力学的研究中,大多学者采用建立LiaPunov函数或者对特定模型进行直接分析以及数值模拟等方式,仅能较为普遍地刻画生态系统的一般性,选用差分方程更能准确地描述种群性态,因此将差分多项式系统的吴方法应用于两种群离散Lotka-Volterra模型的精确求解,并对所得解结构进行分析,为生态学研究提供可靠依据,即分析随着时间的推移种群是持续生存还是走向灭绝.
简介:Inthispaper,aLotka-Volterracooperationsystemwithsinglefeedbackcontrolisproposedandstudied.Weinvestigatethelocalstabilityandtheglobalstabilityofthesystem.Ourstudyshowsthatwithsuitablerestrictiononthecoefficientsofthefeedbackcontrolvariable,thesystemcanstillremaingloballystableorbecomeextinct,whichshowsthatthefeedbackcontrolvariableplaysaveryimportantroleinthedynamicsbehaviorsofthesystem.
简介:Inthispaper,weproposeaLotka-Volterraprey-predatorsystemwithdiscretedelaysandfeedbackcontrol.Firstly,weshowthatsolutionofthesystemisbounded.Secondly,weobtainsufficientconditionfortheglobalstabilityoftheuniquepositiveequilibriumtothesystem.
简介:PERSISTENCEINATHREESPECIESLOTKA-VOLTERRAPERIODICPREDATOR-PREYSYSTEMCHENLansun;PENGQiuliang(InstituteofMathematics,AcademiaSin...
简介:根据区间矩阵理论建立了Lotka-Voherra区间系统,然后利用系统的耗散性研究了它的鲁棒持久性。
简介:Inthispaper,wepresentastabilityanalysisofaLotka-VolterracommensalsymbiosismodelsubjecttoAlleeeffectontheunaffectedpopulationwhichoccursatlowpopulationdensity.ByanalyzingtheJacobianmatrixaboutthepositiveequilibrium,weshowthatthepositiveequilibriumislocallyasymptoticallystable.Byapplyingthedifferentialinequalitytheory,weshowthatthesystemispermanent,consequently,theboundaryequilibriaofthesystemisunstable.Finally,byusingtheDulaccriterion,weshowthatthepositiveequilibriumisgloballystable.AlthoughAlleeeffecthasnoinfluenceonthefinaldensitiesofthepredatorandpreyspecies,numericsimulationsshowthatthesystemsubjecttoanAlleeeffecttakesmuchlongertimetoreachitsstablesteady-statesolution,inthissensethatAlleeeffecthasunstableeffectonthesystem,however,suchaneffectiscontrollable.Suchanfindingisgreatlydifferenttothatofthepredator-preymodel.
简介:利用迭合度理论的连续定理,讨论了一类中立型系统的正周期解的存在性.得到了正周期解存在的一些充分条件.
简介:研究了一类三种群Lotka-Volterra概周期捕食系统,本文结合运用Liapunov函数,得到该系统唯一存在全局渐近稳定的正概周期解的充分条件.
简介:Anon-autonomouscompetingsystemisinvestigatedinthispaper,wherethespeciesxcandiffusebetweentwopatchesofaheterogeneousenvironmentwithbarriersbetweenpatches,butforspeciesy,thediffusiondoesnotinvolveabarrierbetweenpatches,furtheritisassumedthatalltheparametersaretimedependent.Itisshownthatthesystemcanbemadepersistentundersomeappropriateconditions.Moreover,sufficientconditionsthatguaranteetheexistenceofauniquepositiveperiodicorbitwhichisgloballyasymptoticstablearederived.
简介:研究具有捕获项的两种群时滞Lotka-Volterra合作系统的多个正周期解。利用延拓定理和分析技巧得到该系统存在至少4个正周期解的充分条件。
简介:随着中国金融市场的逐渐开放,外资保险在我国也取得了很大的发展,对我国保险市场的影响在逐渐扩大。本文将从中国保险市场结构入手来研究外资保险与中资保险之间的竞合关系。文章借鉴生物界种群竞争的Lotka-Volterra模型来刻画我国范围内中外资人身险的生存环境,选取了2004年8月至2018年9月中外资人身险月保费收入市场份额进行了实证分析,研究结果表明,(1)中外资人身险机构在我国表现为互惠共存的竞争状态;(2)2008年后中外资人身险的自身扩张能力均有所下降,但中资人身险的竞争力有很大的提高,外资人身险的竞争力却在下降。最后根据分析得到的结论,提出一些相应的策略,从而为我国人身险健康发展提供了一些可供参考的理论依据。