Estimate Epidemiological Parameters given Partial Observations based on Algebraically Observable PINNs
Mizuka Komatsu
TL;DR
This work tackles parameter estimation in SEIR-like epidemiological models from partial observations using physics-informed neural networks (PINNs). It introduces algebraic observability, deriving polynomial relationships (e.g., $S = \frac{\ddot{I} + (\epsilon + \gamma)\dot{I} + \epsilon\gamma I}{\beta\epsilon I}$ and $E = \frac{\dot{I} + \gamma I}{\epsilon}$) to recover unobserved states from observed $I$ and its derivatives via Gröbner-basis elimination. The authors propose Algebraically Observable PINNs, leveraging these relations to generate data for unobserved variables and employing a Gaussian process–Bayesian optimization (GP-BO) outer loop to estimate the unknown parameter $\epsilon$ by minimizing test error. The approach achieves accurate trajectory predictions and improved parameter estimation under partial data, offering a practical framework for epidemic inference when observations are limited.
Abstract
In this study, we considered the problem of estimating epidemiological parameters based on physics-informed neural networks (PINNs). In practice, not all trajectory data corresponding to the population estimated by epidemic models can be obtained, and some observed trajectories are noisy. Learning PINNs to estimate unknown epidemiological parameters using such partial observations is challenging. Accordingly, we introduce the concept of algebraic observability into PINNs. The validity of the proposed PINN, named as an algebraically observable PINNs, in terms of estimation parameters and prediction of unobserved variables, is demonstrated through numerical experiments.
