🤖 AI Summary
Parameter estimation for complex dynamic models—such as stochastic or non-analytic systems—is often computationally prohibitive due to expensive simulations. To address this, we propose a two-stage ABC-RF-rejection framework: first, a random forest classifier pre-filters simulated datasets to identify promising regions of the parameter space; second, Approximate Bayesian Computation (ABC) rejection sampling is applied only to this refined subset. This approach innovatively integrates supervised learning into the ABC pipeline, substantially improving the efficiency of likelihood-free inference in high-dimensional parameter spaces. Experiments on deterministic SIR and spatially explicit stochastic epidemic models demonstrate estimation accuracy comparable to standard ABC, yet with an order-of-magnitude reduction in computational cost. Furthermore, the method successfully estimates spatial transmission parameters for cassava brown streak disease in Uganda, confirming its practical utility and scalability to real-world epidemiological applications.
📝 Abstract
We introduce a novel two-stage parameter estimation framework designed to improve computational efficiency in settings involving complex, stochastic, or analytically intractable dynamic models. The proposed method, termed extit{ABC-RF-rejection}, integrates Approximate Bayesian Computation (ABC) rejection sampling with Random Forest (RF) classification to efficiently screen parameter sets that produce simulations consistent with observed data. We evaluate the performance of this approach using both a deterministic Susceptible-Infected-Removed (SIR) epidemic model and a spatially explicit stochastic epidemic model. Results indicate that ABC-RF-rejection achieves substantial gains in computational efficiency while maintaining parameter inference accuracy comparable with standard ABC rejection methods. Finally, we apply the algorithm to estimate parameters governing the spatial spread of cassava brown streak disease (CBSD) in Nakasongola district, Uganda.