Guo-Jun Qi, Charu Aggarwal, et al.
IEEE TPAMI
The problem of factoring positive operators into an "outer" factor and its adjoint has been studied, and its application to the theory of non-stationary random processes is discussed. This problem is an extension of the classical one of factoring positive matrix-valued functions defined on the unit circle of the complex plane into similar factors. © 1971.
Guo-Jun Qi, Charu Aggarwal, et al.
IEEE TPAMI
Naga Ayachitula, Melissa Buco, et al.
SCC 2007
Leo Liberti, James Ostrowski
Journal of Global Optimization
Sankar Basu
Journal of the Franklin Institute