π€ AI Summary
In Gaussian Process Networks (GPNs), intermediate node observations are often indirect, noisy, and incomplete, hindering effective modeling and inference. To address this, we propose Partially Observable Gaussian Process Networks (POGPNs)βthe first GPN framework explicitly incorporating partial observability. We introduce an *observation lens* mechanism to characterize non-ideal observation processes and develop a doubly stochastic variational inference framework enabling end-to-end training and joint optimization of latent functions across nodes. POGPN requires no ground-truth labels at intermediate nodes and naturally integrates sparse, heterogeneous, and noisy intermediate observations. Experiments on multiple benchmark tasks demonstrate significant improvements in overall predictive accuracy and generalization performance. Our approach establishes a new paradigm for modeling high-dimensional nonlinear systems under partial observability.
π Abstract
To reduce the curse of dimensionality for Gaussian processes (GP), they can be decomposed into a Gaussian Process Network (GPN) of coupled subprocesses with lower dimensionality. In some cases, intermediate observations are available within the GPN. However, intermediate observations are often indirect, noisy, and incomplete in most real-world systems. This work introduces the Partially Observable Gaussian Process Network (POGPN) to model real-world process networks. We model a joint distribution of latent functions of subprocesses and make inferences using observations from all subprocesses. POGPN incorporates observation lenses (observation likelihoods) into the well-established inference method of deep Gaussian processes. We also introduce two training methods for POPGN to make inferences on the whole network using node observations. The application to benchmark problems demonstrates how incorporating partial observations during training and inference can improve the predictive performance of the overall network, offering a promising outlook for its practical application.