“…The selection criterions for retaining the basis functions are based on the determination coefficient R 2 and least angle regression technique . Later, many other attempts also have been made to develop sparse PCE model in the field of UQ, the common idea hold in these methods is that the PCE coefficients are sparse (ie, having only several dominant coefficients). Given the training sample { X , Y }, where X = { x 1 , …, x N } T is the input data, Y = { Y 1 , …, Y N } T is the corresponding model response and N is the size of sample, the dominant PCE coefficients can be recovered by solving the following optimization problem where ‖ ω α ‖ 1 is the l 1 norm of PCE coefficients, and ϵ is a tolerance parameter necessitated by the truncation error and Φ ( i , j ) = ψ j ( x i )( i = 1, …, N ; j = 1, …, P + 1) is the measure matrix.…”