Abstract

Front Cover: In article number 2100017, Michael Wulkow and co-workers refine and apply classical and Bayesian parameter estimation for polymerization. This article aims at showing the mathematical connection of both approaches and how their combination can and should be leveraged in a closed workflow to derive a strong understanding of a model and its parameters.

Highlights

  • Introduction for exampleThis article complements these works by a combination of different approaches to the parameter estimation (PE)Parameter estimation (PE) for chemical kinetics means the process of fitting a mathematical model of the reaction process of interest to given observation data by tuning the parameters of the model

  • We make forward simulations with parameters with the simple model (50) which were sampled from the 3D probability distribution for the parameters and visualize the 90% percentile in each time step for these forward simulations

  • We have illustrated, compared, and combined two different approaches to parameter estimation: (1) the classical approach that focuses on minimizing the residual function which measures the distance between the outcome of a model and the observed data, and (2) the Bayesian approach which quantifies the uncertainty that the parameters underlie

Read more

Summary

General Remarks on Parameter Estimation of Chemical Reaction Models

We will concentrate on the PE problem for chemical reaction models that we are going to consider later in this article Such models can be written as systems of ordinary differential equations (ODE). The solution map F is not available in explicit form but can only be computed numerically and comes with the (often considerable) computational effort of computing the trajectory of the ODE system (1) from time 0 to time t. This is especially true for polymerization systems that are solved with respect to full chainlength distributions. As we will see later, if the evaluation of the model function is expensive, this naturally makes the use of the numerical methods we introduce expensive

Measurements
Measurement Errors
Classical versus Bayesian PE
Classical Parameter Estimation
Gauss-Newton Method with Essential Directions
Bayesian Parameter Estimation
Derivation and Fundamentals of Bayesian Modelling
Computing the Posterior and Related Expectation Values
Prescaling of the Step Size
Marginal Densities
Visualization of Densities with Kernel Density Estimation
Examples
Example 1
Estimating Parameters with Data about A
Effect of a Lower Measurement Uncertainty
Uncertainty Propagation
Example 2
The Chemical Reaction Models
Estimation of Parameters
Conclusion
The Metropolis-Hastings Algorithm
Prescaled MALA
We can then solve
Details on Kernel Density Estimation
Test 1
Findings
Data Availability Statement

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.