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We show that any connected regular graph with d+1 distinct eigenvalues and odd-girth 2d+1 is distance-regular, and in particular that it is a generalized odd graph. 相似文献
75.
Flavia Bonomo Guillermo Durán Javier Marenco Mario Valencia-Pabon 《Discrete Applied Mathematics》2011,159(5):288-294
In this paper, we study the minimum sum set coloring (MSSC) problem which consists in assigning a set of x(v) positive integers to each vertex v of a graph so that the intersection of sets assigned to adjacent vertices is empty and the sum of the assigned set of numbers to each vertex of the graph is minimum. The MSSC problem occurs in two versions: non-preemptive and preemptive. We show that the MSSC problem is strongly NP-hard both in the preemptive case on trees and in the non-preemptive case in line graphs of trees. Finally, we give exact parameterized algorithms for these two versions on trees and line graphs of trees. 相似文献
76.
Ching-Yu Yang Yu-Lin Chang Jein-Shan Chen 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(16):5766-5783
Given a Hilbert space H, the infinite-dimensional Lorentz/second-order cone K is introduced. For any x∈H, a spectral decomposition is introduced, and for any function f:R→R, we define a corresponding vector-valued function fH(x) on Hilbert space H by applying f to the spectral values of the spectral decomposition of x∈H with respect to K. We show that this vector-valued function inherits from f the properties of continuity, Lipschitz continuity, differentiability, smoothness, as well as s-semismoothness. These results can be helpful for designing and analyzing solution methods for solving infinite-dimensional second-order cone programs and complementarity problems. 相似文献
77.
In this paper, we study the 3D compressible magnetohydrodynamic equations. We obtain a blow up criterion for the local strong solutions just in terms of the gradient of the velocity, similar to the Beal-Kato-Majda criterion (see J.T. Beal, T. Kato and A. Majda (1984) [1]) for the ideal incompressible flow. In addition, initial vacuum is allowed in our case. 相似文献
78.
Alexander Linke Nicholas E. Wilson 《Journal of Mathematical Analysis and Applications》2011,381(2):612-1221
It was recently proven in Case et al. (2010) [2] that, under mild restrictions, grad-div stabilized Taylor-Hood solutions of Navier-Stokes problems converge to the Scott-Vogelius solution of that same problem. However, even though the analytical rate was only shown to be (where γ is the stabilization parameter), the computational results suggest the rate may be improvable to γ−1. We prove herein the analytical rate is indeed γ−1, and extend the result to other incompressible flow problems including Leray-α and MHD. Numerical results are given that verify the theory. 相似文献
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一类强非线性偏微分方程组初边值问题之逆算符解法新探 总被引:6,自引:0,他引:6
对填充床催化反应器的数学模型──一类强非线性偏微分方程级─边值问题,用逆算符法求其近似解析解,提出了用“部分解的几何平均”替代“部分解的算术平均”的新方法.从而较园满地给出了此类方程组初─边值问题的近似解析解. 相似文献