Nonnegative Matrix Factorization (NMF): A technique for decomposing a data matrix into two nonnegative matrices, enabling the extraction of parts‐based, interpretable features.

P. Bhimasankaram, Dibyen Majumdar, Hermitian and Nonnegative Definite Solutions of Some Matrix Equations Connected with Distribution of Quadratic Forms, Sankhyā: The Indian Journal of Statistics, ...

We apply distortion functions to bivariate survival functions for nonnegative random variables. This leads to a natural extension of univariate distortion risk measures to the multivariate setting.

Peter Li, Mohan Ramachandran, Kähler Manifolds with Almost Nonnegative Ricci Curvature, American Journal of Mathematics, Vol. 118, No. 2 (Apr., 1996), pp. 341-353 ...