arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1907.12973math.DSnlin.CD
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基于捕食者-被捕食者的非法毒品消费数学模型中的混沌

Chaos in a predator-prey-based mathematical model for illicit drug consumption

Jean-Marc Ginoux, Roomila Naeck, Yusra Bibi Ruhomally, Muhammad Zaid Dauhoo, Matjaž Perc

摘要:

最近,有人提出了一个描述由吸毒者和非吸毒者组成的人群中非法药物消费的数学模型。该模型描述了人口中的非用户,实验用户,娱乐用户和成瘾用户的动态。这项工作的目的是提出一个修改后的版本,这个模型的类比与经典的捕食者-被捕食者模型,特别是考虑非用户作为猎物和用户作为捕食者。因此,我们的模型包括一个稳定的影响的增长率的猎物,和不稳定的影响的捕食饱和。Verhulst和Holling II型的功能反应已被用于模拟这些影响。为了预测科罗拉多州和华盛顿州的大麻消费量,我们使用Hanley(2013)的数据和遗传算法来校准模型中的参数。假设非使用者的人口与人口统计学成比例地增加,并遵循罗伯特·梅爵士(1976年)的开创性著作,我们使用非使用者的增长率作为主要的分叉参数。对于科罗拉多州,该模型首先表现出一个极限环,这与Hanley(2013)报告的周期数据相当准确。通过进一步提高非用户的增长率,人口就会进入两个混乱区域,其中变量的演变变得不可预测。对于华盛顿州,该模型也表现出一个周期性的解决方案,这再次是在良好的协议与观测数据。在分岔图中同样观察到华盛顿的混沌区域。我们的研究证实,数学模型可以成为更好地了解非法药物消费和指导决策者制定更有效政策以遏制这一流行病的有用工具。

英文摘要:

Recently, a mathematical model describing the illicit drug consumption in a population consisting of drug users and non-users has been proposed. The model describes the dynamics of non-users, experimental users, recreational users, and addict users within a population. The aim of this work is to propose a modified version of this model by analogy with the classical predator-prey models, in particular considering non-users as prey and users as predator. Hence, our model includes a stabilizing effect of the growth rate of the prey, and a destabilizing effect of the predator saturation. Functional responses of Verhulst and of Holling type II have been used for modeling these effects. To forecast the marijuana consumption in the states of Colorado and Washington, we used data from Hanley (2013) and a genetic algorithm to calibrate the parameters in our model. Assuming that the population of non-users increases in proportion with the demography, and following the seminal works of Sir Robert May (1976), we use the growth rate of non-users as the main bifurcation parameter. For the state of Colorado, the model first exhibits a limit cycle, which agrees quite accurately with the reported periodic data in Hanley (2013). By further increasing the growth rate of non-users, the population then enters into two chaotic regions, within which the evolution of the variables becomes unpredictable. For the state of Washington, the model also exhibits a periodic solution, which is again in good agreement with observed data. A chaotic region for Washington is likewise observed in the bifurcation diagram. Our research confirms that mathematical models can be a useful tool for better understanding illicit drug consumption, and for guiding policy-makers towards more effective policies to contain this epidemic.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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