TY - JOUR ID - Jorgensen2024 LB - Jorgensen2024 AU - Jorgensen, Palle E.T. AU - Song, Myung-Sin AU - Tian, James TI - Conditional mean embedding and optimal feature selection via positive definite kernels ST - Conditional mean embedding and optimal feature selection via positive definite kernels JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2024 VL - 44 IS - 1 SP - 79 EP - 103 DO - https://doi.org/10.7494/OpMath.2024.44.1.79 UR - https://doi.org/10.7494/OpMath.2024.44.1.79 AB - Motivated by applications, we consider new operator-theoretic approaches to conditional mean embedding (CME). Our present results combine a spectral analysis-based optimization scheme with the use of kernels, stochastic processes, and constructive learning algorithms. For initially given non-linear data, we consider optimization-based feature selections. This entails the use of convex sets of kernels in a construction o foptimal feature selection via regression algorithms from learning models. Thus, with initial inputs of training data (for a suitable learning algorithm), each choice of a kernel \(K\) in turn yields a variety of Hilbert spaces and realizations of features. A novel aspect of our work is the inclusion of a secondary optimization process over a specified convex set of positive definite kernels, resulting in the determination of "optimal" feature representations. KW - positive-definite kernels KW - reproducing kernel Hilbert space KW - stochastic processes KW - frames KW - machine learning KW - embedding problems KW - optimization SN - 1232-9274 ER -