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离散等级种群系统的能控性与最优控制 被引量:2
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作者 何泽荣 王晶晶 《高校应用数学学报(A辑)》 北大核心 2020年第4期431-439,共9页
建立具有离散个体等级差异的种群模型,它是一类高维非线性差分方程组.证明了系统的近似能控性;分析了种群资源的最优收获策略,对几种特殊情形获得了最优策略的具体形式,并用数值方法考察了参数变化对最优策略及最优收益的影响.
关键词 个体等级 非线性差分系统 能控性 最优收获 Pontryagin原理
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年龄等级结构捕食种群系统的可控性与镇定 被引量:1
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作者 何泽荣 徐俊芳 《高校应用数学学报(A辑)》 北大核心 2021年第3期253-264,共12页
研究一类基于个体年龄的等级结构捕食种群系统模型的近似可控性及零解镇定问题.以线性系统的可控性结果为基础,运用多值映射的不动点方法证明了非线性系统的可控性,通过构造辅助的最优控制问题给出了控制策略的选取原则.当零解不稳定时... 研究一类基于个体年龄的等级结构捕食种群系统模型的近似可控性及零解镇定问题.以线性系统的可控性结果为基础,运用多值映射的不动点方法证明了非线性系统的可控性,通过构造辅助的最优控制问题给出了控制策略的选取原则.当零解不稳定时,借助反馈控制和共轭系统对镇定所需的迁移控制作了精细描述. 展开更多
关键词 年龄等级 捕食关系 可控性 镇定 Fan-Glicksberg不动点定理 切锥法锥
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一类非线性年龄等级结构种群系统模型的可控性 被引量:1
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作者 何泽荣 周楠 韩梦杰 《高校应用数学学报(A辑)》 北大核心 2020年第2期191-198,共8页
研究一类基于年龄等级差异的种群系统的近似可控性问题,状态方程由非线性偏微分-积分方程描述,且边界条件具有全局反馈特征.运用冻结系数法、线性系统可控性和集值映射不动点原理确立了系统可控性,表明了种群状态可通过个体迁移调节.
关键词 年龄等级 种群模型 偏微分-积分方程 近似可控性 Kakutani不动点
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On the optimal harvesting of size-structured population dynamics 被引量:6
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作者 LIU Yan CHENG Xiao-liang he ze-rong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2013年第2期173-186,共14页
This work is concerned with a kind of optimal control problem for a size-structured biological population model.Well-posedness of the state system and an adjoint system are proved by means of Banach's fixed point the... This work is concerned with a kind of optimal control problem for a size-structured biological population model.Well-posedness of the state system and an adjoint system are proved by means of Banach's fixed point theorem.Existence and uniqueness of optimal control are shown by functional analytical approach.Optimality conditions describing the optimal strategy are established via tangent and normal cones technique.The results are of the first ones for this novel structure. 展开更多
关键词 Body size population model optimal harvest maximum principle normal cone.
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Stability results for a nonlinear two-species competition model with size-structure 被引量:1
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作者 LIU Yan he ze-rong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2021年第1期1-15,共15页
We formulate a system of integro-differential equations to model the dynamics of competition in a two-species community,in which the mortality,fertility and growth are sizedependent.Existence and uniqueness of nonnega... We formulate a system of integro-differential equations to model the dynamics of competition in a two-species community,in which the mortality,fertility and growth are sizedependent.Existence and uniqueness of nonnegative solutions to the system are analyzed.The existence of the stationary size distributions is discussed,and the linear stability is investigated by means of the semigroup theory of operators and the characteristic equation technique.Some sufficient conditions for asymptotical stability/instability of steady states are obtained.The resulting conclusion extends some existing results involving age-independent and age-dependent population models. 展开更多
关键词 COMPETITION size-structure existence and uniqueness SEMIGROUP stability.
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Global positive periodic solutions of age-dependent competing systems
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作者 he ze-rong LIU Li-li LUO Zhi-xue 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2011年第1期38-46,共9页
This paper is to investigate positive periodic solutions of a biological system composed of two competing species. The existence and uniqueness of nonnegative solutions to the model for a set of given vital rates and ... This paper is to investigate positive periodic solutions of a biological system composed of two competing species. The existence and uniqueness of nonnegative solutions to the model for a set of given vital rates and initial distribution are treated and the contractive property of the solutions explored. Based on these results, some simple conditions for the global existence of positive periodic orbits are established by means of Horn's asymptotic fixed point theorem. 展开更多
关键词 Population dynamics AGE-STRUCTURE Poincare mapping fixed point.
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Interactional models for adults of two populations with maturation delays
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作者 he ze-rong LI Jian-quan 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2008年第2期127-135,共9页
This paper is concerned with interactional models for adults of two species delayed by their mature periods. The existence and local stability of equilibria are discussed thoroughly for competitive systems, cooperativ... This paper is concerned with interactional models for adults of two species delayed by their mature periods. The existence and local stability of equilibria are discussed thoroughly for competitive systems, cooperative systems and predator-prey systems, respectively. For systems with interaction of competition and cooperation, it is found that the two populations are uniformly persistent if the positive equilibrium is stable. For predator-prey interaction, however, some further conditions are needed to guarantee the persistence of the systems. 展开更多
关键词 interactional models mature period equilibrium stability uniform persistence.
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