圆盘定理的改进与弱连对角占优矩阵

本文对圆盘定理进行了改进，给出了特征值分布新的估计，由此引出了弱连对角占优矩阵，讨论了其基本性质，重点分析了该类矩阵的逆与分裂特征，证明了在该类矩阵条件下Ｈ－相容分裂是收敛分裂，并给出迭代矩阵谱半径的上界及ＳＯＲ算法中参数ω的选取范围。     

“技术增加值”评价原理与方法

提出了"技术增加值"的概念,认为公司价值不仅包括"经济增加值",还应包括"技术增加值".在系统地比较了"经济增加值"与"技术增加值"两个概念和形成过程的基础上,给出了技术增加值的评价模型、评价方法和评价步骤,最后通过两个应用示例予以说明.提出应用"技术增加值"指标,更加客观反映企业的全面价值和业绩.     

Fast algorithms for placing large entries along the diagonal of a sparse matrix

Solving a sparse system of linear equations Ax=b is one of the most fundamental operations inside any circuit simulator. The equations/rows in the matrix A are often rearranged/permuted before factorization and applying direct or iterative methods to obtain the solution. Permuting the rows of the matrix A so that the entries with large absolute values lie on the diagonal has several advantages like better numerical stability for direct methods (e.g., Gaussian elimination) and faster convergence for indirect methods (such as the Jacobi method). Duff (2009) [3] has formulated this as a weighted bipartite matching problem (the MC64 algorithm). In this paper we improve the performance of the MC64 algorithm with a new labeling technique which improves the asymptotic complexity of updating dual variables from O(|V|+|E|) to O(|V|), where |V| is the order of the matrix A and |E| is the number of non-zeros. Experimental results from using the new algorithm, when benchmarked with both industry benchmarks and UFL sparse matrix collection, are very promising. Our algorithm is more than 60 times faster (than Duff’s algorithm) for sparse matrices with at least a million non-zeros.     

Well-posedness and stability of the repairable system with N failure modes and one standby unit

The well-posedness and stability of the repairable system with N failure modes and one standby unit were discussed by applying the c₀ semigroups theory of function analysis. Firstly, the integro-differential equations described the system were transformed into some abstract Cauchy problem of Banach space. Secondly, the system operator generates positive contractive c₀ semigroups T(t) and so the well-posedness of the system was obtained. Finally, the spectral distribution of the system operator was analyzed. It was proven that 0 is strictly dominant eigenvalue of the system operator and the dynamic solution of the system converges to the steady-state solution. The steady-state solution was shown to be the eigenvector of the system operator corresponding to the eigenvalue 0. At the same time the dynamic solution exponentially converges to the steady-state solution.     

Accurate computation of the smallest eigenvalue of a diagonally dominant -matrix

If each off-diagonal entry and the sum of each row of a diagonally dominant -matrix are known to certain relative accuracy, then its smallest eigenvalue and the entries of its inverse are known to the same order relative accuracy independent of any condition numbers. In this paper, we devise algorithms that compute these quantities with relative errors in the magnitude of the machine precision. Rounding error analysis and numerical examples are presented to demonstrate the numerical behaviour of the algorithms.

     

关于一类p叶解析函数

本文考虑了函数类Tσ（p,a)闭凸包极值点,并用它确定系数估计。对函数类Tσ（p,a)的其它一些有趣性质也进行也研究。     

Positive Solutions of the Equation (t) = −c(t)x(t − τ) in the Critical Case

The equation (t) − c(t)x(t − τ) is considered in the critical case. For it, the asymptotic behavior of dominant and subdominant solutions is studied. A generalization is made and connections with known results are discussed.     

广义严格对角占优矩阵与非奇M矩阵的判定

１引言Ｍ矩阵是计算数学中应给极其广泛的矩阵类,它出现于经济价值模型矩阵和反网络系统分析的系数矩阵及解某类确定微分方程问题的数值解法中．由于Ｍ矩阵的重要性,讨论Ｍ矩阵及相关的广义对角占优矩阵的判定及性质有着十分重要的意义．本文则是在文［１］～［３］基础上,给出了广义严格对角占优矩阵与非奇Ｍ矩阵几则新的充分条件．拓广了文［１］～［３］的相关结果．２主要结果定义１设Ａ＝（ａｉｊ）,如果存在正对角阵Ｄ,使得ＡＤ为严格对角占优阵,则称Ａ为广义严格对角占优阵．定义２设Ａ＝,Ｍ（Ａ）＝（Ｍｉｊ）,其中,则称Ｓ…     

广义对角占优阵的一个等价条件

给出了实方阵为广义对角占优阵的充要条件,同时给出了判断广义对角占优阵可靠,可行,较简单方法。     

The asymptotic behavior of queueing systems: Large deviations theory and dominant pole approximation

This paper presents the exact asymptotics of the steady state behavior of a broad class of single-node queueing systems. First we show that the asymptotic probability functions derived using large deviations theory are consistent (in a certain sense) with the result using dominant pole approximations. Then we present an exact asymptotic formula for the cumulative probability function of the queue occupancy and relate it to the cell loss ratio, an important performance measure for service systems such as ATM networks. The analysis relies on a new generalization of the Taylor coefficients of a complex function which we call characteristic coefficients. Finally we apply our framework to obtain new results for the M/D/1 system and for a more intricate multiclass M/D/n system.