Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Th...Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Then majority domination number of a graph G is γ maj(G)=min{f(V)|f is a majority dominating function on G}. We obtain lower bounds on this parameter and generalize some results of Henning.展开更多
For a simple and connected graph G,denote the domination number,the diameter,and the radius of G asβ(G),D(G),and r(G),respectively.In this paper,we solve two conjectures on the upper bounds ofβ(G)·D(G)andβ(G)+...For a simple and connected graph G,denote the domination number,the diameter,and the radius of G asβ(G),D(G),and r(G),respectively.In this paper,we solve two conjectures on the upper bounds ofβ(G)·D(G)andβ(G)+r(G),which are proposed by the computer system AutoGraphiX.Extremal trees which attain the upper bounds are also considered.展开更多
In this article,some new rigorous perturbation bounds for the SR decomposition un-der normwise or componentwise perturbations for a given matrix are derived.Also,the explicit expressions for the mixed and componentwis...In this article,some new rigorous perturbation bounds for the SR decomposition un-der normwise or componentwise perturbations for a given matrix are derived.Also,the explicit expressions for the mixed and componentwise condition numbers are presented by utilizing the block matrix-vector equation approach.Hypothetical and trial results demonstrate that these new bounds are constantly more tightly than the comparing ones in the literature.展开更多
文摘Let G=(V,E) be a simple graph. For any real valued function f∶V→R and SV, let f(S)=∑ u∈S?f(u). A majority dominating function is a function f∶V→{-1,1} such that f(N)≥1 for at least half the vertices v∈V. Then majority domination number of a graph G is γ maj(G)=min{f(V)|f is a majority dominating function on G}. We obtain lower bounds on this parameter and generalize some results of Henning.
基金This work was supported by National Natural Science Foundation of China(Nos.61222201,11171283)We are grateful to the Journals Editorial Office for the useful suggestions and help.And we gratefully acknowledge the two reviewers who correct some errors of this paper。
文摘For a simple and connected graph G,denote the domination number,the diameter,and the radius of G asβ(G),D(G),and r(G),respectively.In this paper,we solve two conjectures on the upper bounds ofβ(G)·D(G)andβ(G)+r(G),which are proposed by the computer system AutoGraphiX.Extremal trees which attain the upper bounds are also considered.
基金supported by the National Natural Science Foundation of China(Grant No.11771265).
文摘In this article,some new rigorous perturbation bounds for the SR decomposition un-der normwise or componentwise perturbations for a given matrix are derived.Also,the explicit expressions for the mixed and componentwise condition numbers are presented by utilizing the block matrix-vector equation approach.Hypothetical and trial results demonstrate that these new bounds are constantly more tightly than the comparing ones in the literature.
基金supported by NSFSD(No.BS2010SF017,Y2008A04)NNSFC(No.11101245)+1 种基金Foundation of Education Committee of Shandong Province(J07YH03)Foundation of Shandong Institute of Business and Technology(2011QF073)
