Το έργο με τίτλο Karhunen-Loève expansion of Spartan spatial random fields από τον/τους δημιουργό/ούς Tsantili Ivi, Christopoulos Dionysios διατίθεται με την άδεια Creative Commons Αναφορά Δημιουργού 4.0 Διεθνές
Βιβλιογραφική Αναφορά
I.C. Tsantili and D.T. Hristopulos, "Karhunen-Loève expansion of Spartan spatial random fields," Probabilist Eng. Mech., vol. 43, pp. 132-147, Jan. 2016. doi: 10.1016/j.probengmech.2015.12.002
https://doi.org/10.1016/j.probengmech.2015.12.002
Random fields (RFs) are important tools for modeling space-time processes and data. The Karhunen-Loève (K-L) expansion provides optimal bases which reduce the dimensionality of random field representations. However, explicit expressions for K-L expansions only exist for a few, one-dimensional, two-parameter covariance functions. In this paper we derive the K-L expansion of the so-called Spartan spatial random fields (SSRFs). SSRF covariance functions involve three parameters including a rigidity coefficient η1, a scale coefficient, and a characteristic length. SSRF covariances include both monotonically decaying and damped oscillatory functions; the latter are obtained for negative values of η1. We obtain the eigenvalues and eigenfunctions of the SSRF K-L expansion by solving the associated homogeneous Fredholm equation of the second kind which leads to a fourth order linear ordinary differential equation. We investigate the properties of the solutions, we use the derived K-L base to simulate SSRF realizations, and we calculate approximation errors due to truncation of the K-L series.