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arXiv 1705.04436stat.ME
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利用动力系统松弛法推导微分方程模型

Inference for Differential Equation Models using Relaxation via Dynamical Systems

Kyoungjae Lee, Jaeyong Lee, Sarat C. Dass

摘要:

统计回归模型的均值函数由常微分方程(ODE)表示,可以用来描述自然界中的动力学现象,在生物学、气候学和遗传学等领域有着广泛的应用。基于常微分方程的模型的参数估计对于理解其动力学特性是必不可少的,但由于缺乏常微分方程的解析解,使得参数估计具有挑战性。本文的目的是提出一个通用的和快速的框架统计推断基于常微分方程模型的松弛的基本常微分方程系统。松弛是通过适当选择的数值程序,如龙格库塔,并通过引入小方差的加性高斯噪声。因此,可以应用滤波方法来获得贝叶斯框架中的参数的后验分布。该方法的主要优点是计算速度快。在模拟研究中,所提出的方法至少比其他方法快14倍。给出了保证近似动力系统后验收敛到真实模型后验的理论结果。显式表达式给出的顺序和网格大小的龙格库塔程序的收敛速度的近似后作为样本量的函数。

英文摘要:

Statistical regression models whose mean functions are represented by ordinary differential equations (ODEs) can be used to describe phenomenons dynamical in nature, which are abundant in areas such as biology, climatology and genetics. The estimation of parameters of ODE based models is essential for understanding its dynamics, but the lack of an analytical solution of the ODE makes the parameter estimation challenging. The aim of this paper is to propose a general and fast framework of statistical inference for ODE based models by relaxation of the underlying ODE system. Relaxation is achieved by a properly chosen numerical procedure, such as the Runge-Kutta, and by introducing additive Gaussian noises with small variances. Consequently, filtering methods can be applied to obtain the posterior distribution of the parameters in the Bayesian framework. The main advantage of the proposed method is computation speed. In a simulation study, the proposed method was at least 14 times faster than the other methods. Theoretical results which guarantee the convergence of the posterior of the approximated dynamical system to the posterior of true model are presented. Explicit expressions are given that relate the order and the mesh size of the Runge-Kutta procedure to the rate of convergence of the approximated posterior as a function of sample size.

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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