Suzuki单群的一个特性

设Ｄ是一个２－（ｖ,ｋ,１）设计,Ｇ≤ＡｕｔＤ．如果Ｓｚ（ｑ）Ｇ≤Ａｕｔ（Ｓｚ（ｑ））．且Ｇ作用在Ｄ上是线－本原的．则Ｇ作用在Ｄ上也是点－本原的     

Extremal graphs having no matching cuts

A graph G = (V, E) is matching immune if there is no matching cut in G. We show that for any matching immune graph G, |E|≥?3(|V|?1)/2?. This bound is tight, as we define operations that construct, from a given vertex, exactly the class of matching immune graphs that attain the bound. © 2011 Wiley Periodicals, Inc. J Graph Theory 69:206‐222, 2012 .     

海洋动力学中二维黏性原始方程组解对热源的收敛性

考虑了在一个柱形区域上的海洋动力学中二维黏性方程组解的收敛性.在此模型中存在一个关键的参数就是热源,众多周知,它的存在可能会使流体内层之间出现共振从而导致不稳定.因此,通过推导方程组的先验界,得到了方程组的解对热源自身的收敛性.     

A Fibonacci generalization and its dual

An interesting dual sequence for the Fibonacci sequence is presented in which the consecutive terms are constructed via multiplication of the preceding terms, instead of addition. Well-known results illustrating this duality are also generalized, showing how these relate to generalizations of the golden ratio.     

On the diophantine equation x 2 + p 2k = y n

Let 2 ≤ p < 100 be a rational prime and consider equation (3) in the title in integer unknowns x, y, n, k with x > 0, y > 1, n ≥ 3 prime, k ≥ 0 and gcd(x, y) = 1. Under the above conditions we give all solutions of the title equation (see the Theorem). We note that if in (3) gcd(x, y) = 1, our Theorem is an extension of several earlier results [15], [27], [2], [3], [5], [23]. Received: 25 April 2008     

Markov Decision Processes with a Constraint on the Asymptotic Failure Rate

In this paper, we introduce a Markov decision model with absorbing states and a constraint on the asymptotic failure rate. The objective is to find a stationary policy which minimizes the infinite horizon expected average cost, given that the system never fails. Using Perron-Frobenius theory of non-negative matrices and spectral analysis, we show that the problem can be reduced to a linear programming problem. Finally, we apply this method to a real problem for an aeronautical system.     

A method for computing the Perron root for primitive matrices

Following the Perron theorem, the spectral radius of a primitive matrix is a simple eigenvalue. It is shown that for a primitive matrix A, there is a positive rank one matrix X such that B = A ° X , where ° denotes the Hadamard product of matrices, and such that the row (column) sums of matrix B are the same and equal to the Perron root. An iterative algorithm is presented to obtain matrix B without an explicit knowledge of X. The convergence rate of this algorithm is similar to that of the power method but it uses less computational load. A byproduct of the proposed algorithm is a new method for calculating the first eigenvector.     

Directed 3-cycle decompositions of complete directed graphs with quadratic leaves

Let G be a vertex-disjoint union of directed cycles in the complete directed graph D_t, let |E(G)| be the number of directed edges of G and suppose or if t=5, and if t=6. It is proved in this paper that for each positive integer t, there exist -decompositions for D_t−G if and only if .     

Influence of size of solvent molecules on structural and thermodynamic properties of the electrode/electrolyte interface

The influence of size of solvent molecules on the structural and thermodynamic properties of the interface between the electrode and electrolyte, using the solvent primitive model, was studied by grand canonical Monte Carlo (GCMC) simulations. The computer simulation results are compared with those obtained from the modified Poisson–Boltzmann (MPB) theory. The ionic singlet distribution functions show that the solvent molecules of low diameter favour the counter ion adsorption on the electrode. With increasing diameter of the solvent molecules, the mean electrostatic potential increases, while the integral and differential capacitances decrease. The integral capacitance curves obtained by MPB theory are in qualitative agreement with those obtained by the GCMC simulation although the theoretical results are overestimated.     

群与图的对称性

首先对平面图形的对称进行分析和利用其对称群进行量化,进而将此推广到考察一般图的广义"对称性"与图自同构群的关系,最后刻画了无平方因子阶局部本原弧传递图的自同构群结构.