Zimmer Christoph, Sahle Sven
BioQuant, University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany.
IET Syst Biol. 2015 Oct;9(5):181-92. doi: 10.1049/iet-syb.2014.0020.
Estimating model parameters from experimental data is a crucial technique for working with computational models in systems biology. Since stochastic models are increasingly important, parameter estimation methods for stochastic modelling are also of increasing interest. This study presents an extension to the 'multiple shooting for stochastic systems (MSS)' method for parameter estimation. The transition probabilities of the likelihood function are approximated with normal distributions. Means and variances are calculated with a linear noise approximation on the interval between succeeding measurements. The fact that the system is only approximated on intervals which are short in comparison with the total observation horizon allows to deal with effects of the intrinsic stochasticity. The study presents scenarios in which the extension is essential for successfully estimating the parameters and scenarios in which the extension is of modest benefit. Furthermore, it compares the estimation results with reversible jump techniques showing that the approximation does not lead to a loss of accuracy. Since the method is not based on stochastic simulations or approximative sampling of distributions, its computational speed is comparable with conventional least-squares parameter estimation methods.
从实验数据估计模型参数是系统生物学中使用计算模型的一项关键技术。由于随机模型越来越重要,随机建模的参数估计方法也越来越受到关注。本研究提出了一种对“随机系统多重打靶(MSS)”参数估计方法的扩展。似然函数的转移概率用正态分布近似。均值和方差通过在连续测量之间的区间上进行线性噪声近似来计算。与总观测时间相比,系统仅在短区间上进行近似这一事实使得能够处理内在随机性的影响。该研究给出了扩展对于成功估计参数至关重要的情形以及扩展益处不大的情形。此外,它将估计结果与可逆跳跃技术进行比较,表明这种近似不会导致精度损失。由于该方法不基于随机模拟或分布的近似采样,其计算速度与传统最小二乘参数估计方法相当。