{"title":"Stability of the delay logistic equation of population dynamics","authors":"M. Vagina","doi":"10.1109/PHYCON.2003.1236839","DOIUrl":null,"url":null,"abstract":"The nonlinear logistic equation dy/dt=/spl epsiv/y(t) (1-/spl Sigma//sub k=0/ /sup n/b/sub k/y(t-/spl tau//sub k/), /spl epsiv/>0, b/sub k/, /spl tau//spl isin/(0;/spl infin/) (0/spl les/k/spl les/n) is discussed. The local stability of the nonzero stationary solution of this equation depends on the stability of linear equation dx/dt=-/spl Sigma//sub k=1/ /sup n/ a/sub k/x(t-/spl tau//sub k/), where a/sub k/=/spl epsiv/b/sub k///spl Sigma//sub j=0/ /sup n/b/sub j/ (0/spl les/k/spl les/n). It is shown that the condition /spl Sigma//sub k=1/ /sup n/a/sub k//spl tau//sub k/</spl pi//2 is sufficient for zero solution stability of linear equation. We prove, that there is no restriction above on the value /spl Sigma//sub k=1/ /sup n/a/sub k//spl tau//sub k/ which is necessary for the stability of linear equation. It disproves one of the propositions of K. Gopalsamy. It is shown that, if all the delays /spl tau//sub k/ are multiples of one of them: /spl tau//sub k/=k/spl tau/(/spl tau/>0, k=0,l, ..., n), then the stationary solution y/spl equiv/1//spl Sigma//sub k=0/ /sup n/b/sub k/ of logistic equation is stable with respect to small perturbations when the sequence (b/sub k/) is nonnegative and convex.","PeriodicalId":438483,"journal":{"name":"2003 IEEE International Workshop on Workload Characterization (IEEE Cat. No.03EX775)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2003-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2003 IEEE International Workshop on Workload Characterization (IEEE Cat. No.03EX775)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/PHYCON.2003.1236839","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
The nonlinear logistic equation dy/dt=/spl epsiv/y(t) (1-/spl Sigma//sub k=0/ /sup n/b/sub k/y(t-/spl tau//sub k/), /spl epsiv/>0, b/sub k/, /spl tau//spl isin/(0;/spl infin/) (0/spl les/k/spl les/n) is discussed. The local stability of the nonzero stationary solution of this equation depends on the stability of linear equation dx/dt=-/spl Sigma//sub k=1/ /sup n/ a/sub k/x(t-/spl tau//sub k/), where a/sub k/=/spl epsiv/b/sub k///spl Sigma//sub j=0/ /sup n/b/sub j/ (0/spl les/k/spl les/n). It is shown that the condition /spl Sigma//sub k=1/ /sup n/a/sub k//spl tau//sub k/0, k=0,l, ..., n), then the stationary solution y/spl equiv/1//spl Sigma//sub k=0/ /sup n/b/sub k/ of logistic equation is stable with respect to small perturbations when the sequence (b/sub k/) is nonnegative and convex.