“…Since the same problem can be posed as a supervised learning task, a lot of recent interest has been shifting to machine learning approaches. Among the linear estimators, a popular approach is the kernelbased method [9,42,17,51,35,10,11], whose connection to the parametric modeling paradigm has been studied in [31]. In this direction, many nonparametric models have been proposed, including the orthogonal polynomials [51], wavelets [42], Gaussian processes [17], radial kernels [17], diffusion maps based models [4,5,18], just to name a few.…”