On the necessity and sufficiency of PLUS factorizations
نویسندگان
چکیده
PLUS factorizations, or customizable triangular factorizations, of nonsingular matrices have found applications in source coding and computer graphics. However, there are still some open problems. In this paper, we present a new necessary condition and a sufficient condition for the existence of generic PLUS factorizations. © 2004 Elsevier Inc. All rights reserved.
منابع مشابه
On the Necessity and Sufficiency of Universals
On the Necessity and Sufficiency of Universals
متن کاملILU and IUL factorizations obtained from forward and backward factored approximate inverse algorithms
In this paper, an efficient dropping criterion has been used to compute the IUL factorization obtained from Backward Factored APproximate INVerse (BFAPINV) and ILU factorization obtained from Forward Factored APproximate INVerse (FFAPINV) algorithms. We use different drop tolerance parameters to compute the preconditioners. To study the effect of such a dropping on the quality of the ILU ...
متن کاملComparative Advantage, Self-sufficiency and Food Security in Iran: Case Study of Wheat Commodity
Food security has a dynamic notion during the time and may be affected by various domestic and global factors.Nevertheless, Iranian policy makers consider food security as same as self-sufficiency in agricultural food products, particularly wheat production. However, self-sufficiency can contribute to food security only if it is in coincidences with comparative advantage and sustainable resourc...
متن کاملRiordan group approaches in matrix factorizations
In this paper, we consider an arbitrary binary polynomial sequence {A_n} and then give a lower triangular matrix representation of this sequence. As main result, we obtain a factorization of the innite generalized Pascal matrix in terms of this new matrix, using a Riordan group approach. Further some interesting results and applications are derived.
متن کاملFace numbers of generalized balanced Cohen-Macaulay complexes
A common generalization of two theorems on the face numbers of Cohen–Macaulay (CM, for short) simplicial complexes is established: the first is the theorem of Stanley (necessity) and Björner-Frankl-Stanley (sufficiency) that characterizes all possible face numbers of a-balanced CM complexes, while the second is the theorem of Novik (necessity) and Browder (sufficiency) that characterizes the fa...
متن کامل