free parameter
Spatial Covariance Constraints for Gaussian Mixture Models
Lu, Hanzhang, Malott, Keiran, Bitra, Venkat Suprabath, Milligan, Kirsty, Subedi, Sanjeena, Cassol, Edana, Chauhan, Vinita, McNairn, Connor, Muir, Bryan, Pasricha, Prarthana, Murugkar, Sangeeta, Thomson, Rowan, Jirasek, Andrew, Andrews, Jeffrey L.
Although extensive research exists in spatial modeling, few studies have addressed finite mixture model-based clustering methods for spatial data. Finite mixture models, especially Gaussian mixture models, particularly suffer from high dimensionality due to the number of free covariance parameters. This study introduces a spatial covariance constraint for Gaussian mixture models that requires only four free parameters for each component, independent of dimensionality. Using a coordinate system, the spatially constrained Gaussian mixture model enables clustering of multi-way spatial data and inference of spatial patterns. The parameter estimation is conducted by combining the expectation-maximization (EM) algorithm with the generalized least squares (GLS) estimator. Simulation studies and applications to Raman spectroscopy data are provided to demonstrate the proposed model.
Discovering the Underlying Analytic Structure Within Standard Model Constants Using Artificial Intelligence
Chekanov, S. V., Kjellerstrand, H.
This paper presents a method for uncovering hidden analytic relationships among the fundamental parameters of the Standard Model (SM), a foundational theory in physics that describes the fundamental particles and their interactions, using symbolic regression and genetic programming. Using this approach, we identify the simplest analytic relationships connecting pairs of these constants and report several notable expressions obtained with relative precision better than 1%. These results may serve as valuable inputs for model builders and artificial intelligence methods aimed at uncovering hidden patterns among the SM constants, or potentially used as building blocks for a deeper underlying law that connects all parameters of the SM through a small set of fundamental constants.