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生化反应网络中的参数估计:一种基于观察者的方法

Parameter estimation in biochemical reaction networks: An observer-based approach
课程网址: https://videolectures.net/categories/58  
主讲教师: Eric Bullinger
开课单位: 信息不详。欢迎您在右侧留言补充。
开课时间: 2008-04-07
课程语种: 英语
中文简介:
生物系统建模的一个重要瓶颈是缺乏动力学参数的实验数据。测量技术的最新进展增加了从时间序列数据中推断这些参数的可行性(Anguelova等人,2007;Voit和Almeida,2004)。我们提出了一种从时间序列数据中估计动力学参数的方法,该方法特别适用于由非线性常微分方程组成的生物模型,特别是对于非线性为多项式的系统,如质量作用或广义质量作用动力学,或状态的有理函数,如Michaelis-Menten或Hill动力学。拟议的方法包括三个步骤。首先,将系统转化为观测器范式的扩展系统。扩展系统只依赖于结构信息,而不依赖于参数值(Xia和Zeitz,1997;Fey等人,2008)。这允许设计一个高增益观测器来估计扩展系统的状态(Vargas和Moreno,2005)。由于扩展系统并非处处可观测,而只能观测轨迹,因此观测器只能是近似观测器。然而,观测器误差可以选择为任意小。在最后一步中,基于观测器状态确定参数,作为这些状态的简单非线性函数的唯一解。因此,所提出的参数方案估计是一种全局估计算法。参数估计方法在脉孢菌昼夜节律的简单模型上进行了说明(Leloup等人,1999)。该模型包含三种物质、六种反应,并表现出与昼夜周期相对应的自主振荡。所提出的基于观测器的参数估计方法能够恢复所有参数,即使轨迹接近可观测性的奇点。
课程简介: An important bottleneck in the modelling of biological systems is the scarcity of experimental data on kinetic parameters. Recent advances in measurement technologies increase the feasibility of infer ring these parameters from time series data (Anguelova et al., 2007; Voit and Almeida, 2004). We present a methodology for estimating kinetic parameters from time series data, in a way that is particularly tailored to biological models consisting of nonlinear ordinary differential equations, in particular for systems in which the nonlinearities are polynomial, such as in mass action or generalised mass action kinetics, or rational functions of the states, as in Michaelis-Menten or Hill kinetics. The proposed approach consists of three steps. First, the system is transformed into an ex- tended system in observer normal form. The extended system does only depend on structural information, not on the value of the parameters (Xia and Zeitz, 1997; Fey et al., 2008). This allows to design a high-gain observer estimating the states of the extended system (Vargas and Moreno, 2005). As the extended system is not observable everywhere, but only trajectory ob- servable, the observer can only be an approximate observer. However, the observer error can be chosen to be arbitrarily small. In a final step, the parameters are determined based on the observer states, as the unique solutions of simple nonlinear functions of these states. Thus, the proposed parameter scheme estimates is a global estimation algorithm. The parameter estimation methodology is illustrated on a simple model of the circadian rhythm in neurospora (Leloup et al., 1999). The model contains three species, six reactions and exhibits autonomous oscillations corresponding to the day-night cycle The proposed observer-based pa- rameter estimation method is able to recover all parameters, even if the trajectory comes close to singularities of the observability.
关 键 词: 生物系统建模; 动力学参数; 非线性常微分方程组成的生物模型
课程来源: vidiolectures
数据采集: 2025-02-24:yuhongrui
最后编审: 2025-02-24:yuhongrui
阅读次数: 1