In this paper,the normative matrices and their double LR transformationwith origin shifts are defined,and the essential relationship between the double LR transformation of a normative matrix and the QR transformation...In this paper,the normative matrices and their double LR transformationwith origin shifts are defined,and the essential relationship between the double LR transformation of a normative matrix and the QR transformation of the related symmetrictridiagonal matrix is proved.We obtain a stable double LR algorithm for double LRtransformation of normative matrices and give the error analysis of our algorithm.Theoperation number of the stable double LR algorithm for normative matrices is only foursevenths of the rational QR algorithm for real symmetric tridiagonal matrices.展开更多
Let G be a finite simple graph with adjacency matrix A, and let P（A） be the convex closure of the set of all permutation matrices commuting with A. G is said to be compact if every doubly stochastic matrix which com...Let G be a finite simple graph with adjacency matrix A, and let P（A） be the convex closure of the set of all permutation matrices commuting with A. G is said to be compact if every doubly stochastic matrix which commutes with A is in P（A）. In this paper, we characterize 3-regular compact graphs and prove that if G is a connected regular compact graph, G - v is also compact, and give a family of almost regular compact connected graphs.展开更多
文摘In this paper,the normative matrices and their double LR transformationwith origin shifts are defined,and the essential relationship between the double LR transformation of a normative matrix and the QR transformation of the related symmetrictridiagonal matrix is proved.We obtain a stable double LR algorithm for double LRtransformation of normative matrices and give the error analysis of our algorithm.Theoperation number of the stable double LR algorithm for normative matrices is only foursevenths of the rational QR algorithm for real symmetric tridiagonal matrices.
基金Supported by National Natural Science Foundation of China(Grant No.19971086)
文摘Let G be a finite simple graph with adjacency matrix A, and let P（A） be the convex closure of the set of all permutation matrices commuting with A. G is said to be compact if every doubly stochastic matrix which commutes with A is in P（A）. In this paper, we characterize 3-regular compact graphs and prove that if G is a connected regular compact graph, G - v is also compact, and give a family of almost regular compact connected graphs.
