Model reduction for slow-fast stochastic systems with metastable behaviour
Model reduction for slow-fast stochastic systems with metastable behaviour
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DOI：
10.1063/1.4871694
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发表时间：
2014-05-07
影响因子：
4.4
通讯作者：
Smith, Matthew J.
中科院分区：
文献类型：
--
作者：
Bruna, Maria;Chapman, S. Jonathan;Smith, Matthew J.
准稳态近似(或随机平均原理)是研究多尺度随机系统的一种有用的工具，它给出了一种减少模型自由度的实用方法。本文将该方法推广到快变量呈现亚稳态行为的快慢系统。决定简化模型形式的关键参数是用于在亚稳态之间切换快变量的时间尺度与用于慢变量演化的时间尺度的比率。该方法用两个例子来说明：一个来自生物化学(一种快速的物种中介的化学开关，连接到一个变化较慢的物种)，另一个来自生态学(捕食者-猎物系统)。将每一次模型降阶的数值模拟与整个系统的数值模拟进行了比较。(C)2014 AIP出版有限责任公司。
The quasi-steady-state approximation (or stochastic averaging principle) is a useful tool in the study of multiscale stochastic systems, giving a practical method by which to reduce the number of degrees of freedom in a model. The method is extended here to slow-fast systems in which the fast variables exhibit metastable behaviour. The key parameter that determines the form of the reduced model is the ratio of the timescale for the switching of the fast variables between metastable states to the timescale for the evolution of the slow variables. The method is illustrated with two examples: one from biochemistry (a fast-species-mediated chemical switch coupled to a slower varying species), and one from ecology (a predator-prey system). Numerical simulations of each model reduction are compared with those of the full system. (C) 2014 AIP Publishing LLC.