(s,t,d)-bi-Koszul代数

本文关注具有non-pure分解的1次生成正分次代数,主要讨论作为bi-Koszul代数的推广的一类新的代数(s,t,d)-bi-Koszul代数.用两个具有pure分解的周期代数可以获得(s,t,d)-bi-Koszul代数.本文讨论了(s,t,d)-bi-Koszul代数的Koszul对偶的生成性,在此基础上,提出了强(s,t,d)-bi-Koszul代数的概念并且进一步讨论了它们的同调性质.     

胞腔代数的箭图构造(英文)

本文研究了胞腔代数.利用箭图及关系,我们刻画民平凡扩张是胞腔代数的路代数,并得到了两种直接构造胞腔代数的方法.     

Toroidal李代数上的Poisson代数结构

非交换的Poisson代数同时具有结合代数和李代数两种代数结构,而结合代数和李代数之间满足所谓的Leibniz法则.文中确定了Toroidal李代数上所有的Poisson代数结构,推广了仿射Kac-Moody代数上相应的结论.     

AR箭图,例外序列与导出Hall代数中的算法

如果半单Lie代数g和有限维遗传代数Λ对应于相同的Dynkin图,则有量子群U_q(g)的正部分U~+典范地同构于Hall代数H(Λ).一个自然的问题是:如何将U+中的根向量分解为Chevalley生成元的单项式的线性组合?Chen和Xiao给出的两种算法分别利用了Λ-模的例外序列上的辫子群作用以及Λ的Auslander-Reiten箭图的结构.对于To(e|¨)n定义的导出Hall代数,本文提出了类似的问题.并得到了相应的两种算法.这两种算法也同样适用于Kapranov定义的格代数和Heisenberg double.而且,所有新的递归公式都具有和量子Serre关系相似的形式.     

树型代数拟遗传序的组合公式及其算法

本文给出了树型代数的拟遗传序数的精确上界以及单生成元的树型代数的拟遗传序数的精确下界及其算法 ,并由此得到一个新的组合公式 .     

广义仿射李代数上的非交换Poisson代数结构

非交换的Poisson代数同时具有(未必交换的)结合代数和李代数两种代数结构,且结合代数和李代数之间满足所谓的Leibniz法则.本文确定了一般广义仿射李代数上所有的Poisson代数结构.     

仿射括号代数理论与算法及其在几何定理机器证明中的应用

主要讨论仿射括号代数的理论与算法及其在定理机器证明中的应用。文中首次提出了边界扩张算法等几个有效的仿射括号代数算法, 同时分析了边界算子的性质, 为系统实现奠定了基础. 文中也提及了单括号因子整除判定、单项式因子整除判定、仿射几何的构造和对应表示表示等工作. 在符号计算软件 Maple 10中, 应用上述理论与算法实现了仿射几何的定理机器 证明, 并用大约100多个例子进行了测试, 之后将结果进行了比较.     

Fuzzy锁代数

众所周知,论域X上的全体Fuzzy子集[0,1]~x,在L. A. Zadeh的∪,∩,C(余运算)意义下,由于排中律不成立,而只能构成“软”代数。可是我们还注意到了Giles. R在1976年提出的算子(?),(?)及C运算所构成的代数系统,确定非分配的“硬”代数结构。本文从这一类算子出发,抽象出一个新的代数系统——Fuzzy锁代数。并研究了它的代数结构。     

Kadison-Singer代数研究综述

回顾了建立KS-代数的研究背景,系统介绍了KS-代数的定义和性质以及超有限KS-代数、非超有限KS-代数、KS-格的构造和强KS-代数的研究结果,同时分析了KS-代数和经典的不变子空间、Kadison可迁代数、von Neumann代数生成元等问题之间的联系;讨论了非自伴代数的运算,给出了两种不同构造非自伴代数的运算法则;在此基础上,提出了未来学科发展有待研究的16个问题.     

基于代数神经网络的煤自燃预测

代数神经网络算法能够克服BP神经网络易于陷入局部极小和收敛慢的问题,通过优选激励函数和采用代数算法计算权值,将复杂的非线性优化问题转化为简单的代数方程组求解问题,提高了神经网络的精度与收敛速度.在使用代数神经网络算法进行煤自燃预测的实例中,采用均值规格化数据预处理,解决了煤自燃指标气体异动对分类结果的过度扰动.实验结果表明了算法的有效性和实用性.     

一个古老等式的组合证明

采用组合的方法,对∑nk=0n+kknk(m-1)n-k=∑nk=0nk2mk这一等式提供了一种全新的证明.此外,还提供了一种完全不用微积分的代数证明.     

Comparing stability properties of three methods in DAEs or ODEs with invariants

Three approaches for solving ODEs with invariants or DAEs are the constrained least squares method, the coordinate projection method and the derivative projection method. The stability properties of these three methods are compared for linear ODEs with linear invariants. There exist examples where each of the three approaches is to prefer.     

Algebraic analysis of aggregation‐based multigrid

A convergence analysis of two‐grid methods based on coarsening by (unsmoothed) aggregation is presented. For diagonally dominant symmetric (M‐)matrices, it is shown that the analysis can be conducted locally; that is, the convergence factor can be bounded above by computing separately for each aggregate a parameter, which in some sense measures its quality. The procedure is purely algebraic and can be used to control a posteriori the quality of automatic coarsening algorithms. Assuming the aggregation pattern is sufficiently regular, it is further shown that the resulting bound is asymptotically sharp for a large class of elliptic boundary value problems, including problems with variable and discontinuous coefficients. In particular, the analysis of typical examples shows that the convergence rate is insensitive to discontinuities under some reasonable assumptions on the aggregation scheme. Copyright © 2010 John Wiley & Sons, Ltd.     

Two‐level preconditioners for serendipity finite element matrices

In this paper an approach to construct algebraic multilevel preconditioners for serendipity finite element matrices is presented. Two‐level preconditioners constructed in the paper allow to obtain multilevel preconditioners in serendipity case using multilevel preconditioners for linear finite element matrices. Copyright © 2006 John Wiley & Sons, Ltd.     

Jaulent-Miodek方程组和长水波近似方程组的新精确解

首先,利用直接代数法给出了一类非线性方程的四组显式精确解的公式.进而,很方便地得到了Jaulent-Miodek方程组和长水波近似方程组的若干新精确解.     

THE ALGEBRAIC METHOD OF RATIONAL INTERPOLATION

This paper deals with rational interpolation. From algebraic viewpoint, we present an algebraic formulation of rational interpolation and discuss the existence of the interpolation function. Finally an algorithm for univariate case and an example are presented.     

Structure of coordinate groups for algebraic sets in partially commutative nilpotent groups

The results obtained deal in algebraic geometry over partially commutative class two nilpotent ℚ-groups, where ℚ is a field of rationals. It is proved that two arbitrary non-Abelian partially commutative class two nilpotent ℚ-groups are geometrically equivalent. A necessary and sufficient condition of being universally geometrically equivalent is specified for two partially commutative class two nilpotent ℚ-groups. Algebraic sets for systems of equations in one variable, as well as for some special systems in several variables, are described. Dedicated to V. N. Remeslennikov on the occasion of his 70th birthday Translated from Algebra i Logika, Vol. 48, No. 2, pp. 378–399, May–June, 2009.     

非结构四边形二次Lagrangian有限元方程的代数多重网格法及收敛性分析

1 引言代数多重网格(AMG)法是求解有结构、非结构冈格下的PDEs离散化系统,以及其它大型稀疏矩阵方程的最为有效的方法之一,是当前多重网格法研究领域的热点．它主要侧重于粗化技术的研究,目前这方面已有大量的工作(见文[1～4]),其中基于部分几何信息和分析信息的AMG法,是当前AMG法发展的一个新趋势(见文[5～7])．     

Certain Diophantine Properties of the Mahler Measure

It is proved that a polynomial in several Mahler measures with positive rational coefficients is equal to an integer if and only if all these Mahler measures are integers. An estimate for the distance between a metric Mahler measure and an integer is obtained. Finally, it is proved that the ratio of two distinct Mahler measures of algebraic units is irrational.     

Construction of iteration functions for the simultaneous computation of the solutions of equations and algebraic systems

We construct iteration functions for the simultaneous computation of the solutions of a system of equations, with local quadratic convergence: they generalize to the multivariate case the well-known Weierstrass function for polynomials, which is expected to be globally convergent except on a zero-measured set of starting points. We clarify these functions using univariate interpolation. Both for polynomials and algebraic systems with real coefficients, we extend the conjecture of global convergence to the research of real roots or solutions.