论文标题

另一种延迟人口增长方程模型

An alternative delayed population growth difference equation model

论文作者

Streipert, Sabrina H., Wolkowicz, Gail S. K.

论文摘要

我们提出了一个基于贝弗顿荷尔特复发的修改的替代延迟人口增长方程模型,假设仅考虑到那些在延迟期间死亡的个体不会促进增长的人的增长贡献延迟。该模型引入的与人口动态的现有延迟差方程不同,例如延迟的逻辑差方程,该方程是将Hutchinson模型离散化的。对我们延迟差方程模型的分析确定了重要的临界延迟阈值。如果时间延迟超过此阈值,该模型预测,所有非负初始条件的种群将灭绝,如果其低于此阈值,人口存活,其大小会收敛到全球渐近稳定稳定的正平衡,随着延迟的增加,大小的大小降低。首先,我们通过利用Jacobian矩阵的特殊结构来获得局部稳定结果。其次,我们表明局部稳定性意味着使用两种不同技术的全局稳定性。对于一组参数值,将应用一个收缩映射结果,而对于其余的参数值集,我们证明了结果是首先证明复发结构在其每个参数中最终都是单调的。

We propose an alternative delayed population growth difference equation model based on a modification of the Beverton-Holt recurrence, assuming a delay only in the growth contribution that takes into account that those individuals that die during the delay, do not contribute to growth. The model introduced differs from existing delay difference equations in population dynamics, such as the delayed logistic difference equation, which was formulated as a discretization of the Hutchinson model. The analysis of our delayed difference equation model identifies an important critical delay threshold. If the time delay exceeds this threshold, the model predicts that the population will go extinct for all non-negative initial conditions and if it is below this threshold, the population survives and its size converges to a positive globally asymptotically stable equilibrium that is decreasing in size as the delay increases. Firstly, we obtain the local stability results by exploiting the special structure of powers of the Jacobian matrix. Secondly, we show that local stability implies global stability using two different techniques. For one set of parameter values, a contraction mapping result is applied, while for the remaining set of parameter values, we show that the result follows by first proving that the recurrence structure is eventually monotonic in each of its arguments.

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