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101.
Isidoro Gitler 《Discrete Mathematics》2010,310(3):430-441
We study the family of graphs whose number of primitive cycles equals its cycle rank. It is shown that this family is precisely the family of ring graphs. Then we study the complete intersection property of toric ideals of bipartite graphs and oriented graphs. An interesting application is that complete intersection toric ideals of bipartite graphs correspond to ring graphs and that these ideals are minimally generated by Gröbner bases. We prove that any graph can be oriented such that its toric ideal is a complete intersection with a universal Gröbner basis determined by the cycles. It turns out that bipartite ring graphs are exactly the bipartite graphs that have complete intersection toric ideals for any orientation. 相似文献
102.
Armando V. Corro Francisco Milán 《Journal of Mathematical Analysis and Applications》2010,366(2):582-592
We construct examples of flat surfaces in H3 which are graphs over a two-punctured horosphere and classify complete embedded flat surfaces in H3 with only one end and at most two isolated singularities. 相似文献
103.
利用完备分配格L上的s-模定义格L上的矩阵运算,给出这些运算的一些基本性质,并且定义格L上的s-幂零矩阵,给出一些全新的结果. 相似文献
104.
The psi function ψ(x) is defined by ψ(x)=Γ′(x)/Γ(x), where Γ(x) is the gamma function. We give necessary and sufficient conditions for the function ψ″(x)+[ψ′(x+α)]2 or its negative to be completely monotonic on (−α,∞), where . We also prove that the function [ψ′(x)]2+λψ″(x) is completely monotonic on (0,∞) if and only if λ1. As an application of the latter conclusion, the monotonicity and convexity of the function epψ(x+1)−qx with respect to x(−1,∞) are thoroughly discussed for p≠0 and . 相似文献
105.
Rembert Reemtsen 《Applicable analysis》2013,92(2):357-390
In this article special (possibly constrained) problems of linear and nonlinear complex approximation are studied with respect to the existence and uniqueness of solutions and the convergence of the approximation errors, where the errors are measured by an arbitrary L p and l p norm respectively. The problems arise in connection with the frequency and magnitude response approximation at the design of nonrecursive digital filters in the frequency domain. Two main results of the article concern the completeness of the functions exp ( m ik y ), k = 0,1,2,… , with respect to a certain space of continuous functions. These results imply that, under usual assumptions and with increasing number of approximating functions exp ( m ik y ), the errors in the frequency and magnitude response approximation problems converge to zero when the design region is not the total interval [0, ~ ] (in case of real coefficients) and not [ m ~ , ~ ] (in case of complex coefficients) which is given for the majority of filter design problems, but that the frequency response errors may not converge to zero when the design region equals [0, ~ ] or [ m ~ , ~ ] respectively. 相似文献
106.
David A. Jorgensen 《代数通讯》2013,41(12):4461-4471
107.
108.
Masahiro Ohtani 《代数通讯》2013,41(10):3858-3867
In this article, we prove some results about the binomial edge ideal J G of a complete r-partite graph G = K a 1,…, a r : (1) characterization of unmixedness of J G and Cohen–Macaulayness of the residue ring S/J G , (2) F-purity of S/J G , and (3) the equality of the symbolic and the ordinary powers of J G . 相似文献
109.
Harun Karsli 《Numerical Functional Analysis & Optimization》2013,34(11):1206-1223
The purpose of this article is to study the local rate of convergence of the Chlodovsky operators (Cnf)(x). As the main results, we investigate their asymptotic behaviour and derive the complete asymptotic expansions of these operators. All the coefficients of n?k (k = 1, 2,…) are calculated in terms of the Stirling numbers of first and second kind. We mention that analogous results for the Bernstein polynomials can be found in Lorentz [2]. 相似文献
110.