A General Framework for Enhancing Sparsity of Generalized Polynomial Chaos Expansions
For researchers in uncertainty quantification, this provides a more general and effective sparsity enhancement method, though it is an incremental extension of prior work on Hermite expansions.
The paper proposes a general framework using alternating direction method to enhance sparsity of generalized polynomial chaos expansions, improving efficiency and accuracy of compressive sensing-based uncertainty quantification. Demonstrated on Legendre and Chebyshev expansions for stochastic PDEs and high-dimensional problems (O(100)).
Compressive sensing has become a powerful addition to uncertainty quantification when only limited data is available. In this paper we provide a general framework to enhance the sparsity of the representation of uncertainty in the form of generalized polynomial chaos expansion. We use alternating direction method to identify new sets of random variables through iterative rotations such that the new representation of the uncertainty is sparser. Consequently, we increases both the efficiency and accuracy of the compressive sensing-based uncertainty quantification method. We demonstrate that the previously developed iterative method to enhance the sparsity of Hermite polynomial expansion is a special case of this general framework. Moreover, we use Legendre and Chebyshev polynomials expansions to demonstrate the effectiveness of this method with applications in solving stochastic partial differential equations and high-dimensional (O(100)) problems.