共查询到20条相似文献,搜索用时 109 毫秒
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向量到子空间的距离及其应用 总被引:1,自引:0,他引:1
给出了向量到有限维子空间距离的定义及求法 ,并推广到向量到可数无限维子空间距离 .采用两种方法求距离并比较了它们的运算量 .揭示了 Cholesky分解法与 Schmidt正交化方法的内在联系 .最后利用向量到子空间距离给出了矛盾方程组最小二乘解的求法 相似文献
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《应用数学与计算数学学报》2017,(1)
提出了一阶常微分方程初值问题的Legendre-tau方法,根据一阶微分算子不对称性的特点,tau方法选取检验函数不同于试探函数,有更好的逼近性质,改进了误差估计.文中给出了单步和多步Legendre-tau方法及算法实现,采用系数为未知量,可利用多项式的正交性减少运算量.数值结果与理论分析一致,并与相关方法进行比较,验证了本文方法的有效性. 相似文献
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1971年,M.H.C.Paardekooper将对称阵的Jacobi思想推广到反对称阵,给出一个求反对称阵特征值的实用算法(简称P算法).但P算法仅考虑到矩阵的反对称性,未利用其纯虚数特征值共轭成对的性质,而且也未探讨特征值共轭对相重与否对运算量的影响.鉴于此,本文提出一个新算法,其运算量比P算法少得多. 我们先用Givens相似变换(其快速算法见§3之3.2)化反对称阵A为三对角反对称 相似文献
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本文首先根据Runge-Kutta方法的思想,结合Newton迭代法,提出了一类带参数的解非线性方程组F(x)=0的迭代算法,然后基于解非线性方程f(x)=0的King算法,给出第二类解非线性方程组的迭代算法,收敛性分析表明这两类算法都是五阶收敛的.其次给出了本文两类算法的效率指数,以及一些已知算法的效率指数,并且将本文算法的效率指数与其它方法进行详细的比较,通过效率比率R_(i,j)可知本文算法具有较高的计算效率.最后给出了四个数值实例,将本文两类算法与现有的几种算法进行比较,实验结果说明本文算法收敛速度快,迭代次数少,有明显的优势. 相似文献
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本文基于两个非线性逼近逆的非线性Uzawa方法,给出了一种新的修正非线性Uzawa方法,并对其收敛性进行了分析以及与已有算法的收敛性进行了比较.最后由数值试验说明了算法的正确性和有效性. 相似文献
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线性最优化广泛应用于经济与管理的各个领域.在线性规划问题的求解中,如果一个初始基本可行解没有直接给出,则常采用经典的两阶段法求解.对含有"≥"不等式约束的线性规划问题,讨论了第一阶段原有单纯形法和对偶单纯形法两种算法形式,并根据第一阶段问题的特点提出了改进的对偶单纯形枢轴准则.最后,通过大规模数值试验对两种算法进行计算比较,结果表明,改进后的对偶单纯形算法在计算效率上明显优于原有单纯形算法. 相似文献
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This paper discusses processing software for large scale mixed-integer optimization models. The software is part of the Mathematical OPtimization System MOPS [18] which contains algorithms for solving large-scale LP and mixed-integer programs. The processing techniques are implemented in such a way that they can be applied not only initially but also during the branch-and-bound algorithm.This paper discusses only a subset of the processing techniques included in MOPS. Algorithmic and software design aspects of the branch-and-bound process are not part of this paper.Dedicated to Professor George B. Dantzig on the occasion of his eightieth birthday. 相似文献
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George M. Phillips 《BIT Numerical Mathematics》1997,37(1):232-236
This paper is concerned with a generalization of the classical Bernstein polynomials where the function is evaluated at intervals
which are in geometric progression. It is shown that these polynomials can be generated by a de Casteljau algorithm, which
is a generalization of that relating to the classical case.
Dedicated to M. J. D. Powell on the occasion of his 60th birthday 相似文献
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B. Cao 《Mathematical Methods of Operations Research》1992,36(2):185-197
In a container terminal management, we are often confronted with the following problem: how to assign a reasonable depositing position for an arriving container, so that the efficiency of searching for and loading of a container later can be increased. In this paper, the problem is modeled as a transportation problem with nonlinear side constraints (TPNSC). The reason of nonlinear side constraints arising is that some kinds of containers cannot be stacked in the same row (the space of storage yard is properly divided into several rows). A branch and bound algorithm is designed to solve this problem. The algorithm is based on the idea of using disjunctive arcs (branches) for resolving conflicts that are created whenever some conflicting kinds of containers are deposited in the same row. During the branch and bound, the candidate problems are transformed into classical transportation problems, so that the efficient transportation algorithm can be applied, at the same time the reoptimization technique is employed during the branch and bound. Further, we design a heuristic to obtain a feasible initial solution for TPNSC in order to prune some candidates as early and/or as much as possible. We report computational results on randomly generated problems. 相似文献
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A. Kusiak 《Annals of Operations Research》1985,3(6):277-300
Parts grouping into families can be performed in flexible manufacturing systems (FMSs) to simplify two classes of problems: long horizon planning and short horizon planning. In this paper the emphasis is on the part families problem applicable to the short horizon planning. Traditionally, parts grouping was based on classification and coding systems, some of which are reviewed in this paper. To overcome the drawbacks of the classical approach to parts grouping, two new methodologies are developed. The methodologies presented are very easy to implement because they take advantage of the information already stored in the CAD system. One of the basic elements of this system is the algorithm for solving the part families problem. Some of the existing clustering algorithms for solving this problem are discussed. A new clustering algorithm has been developed. The computational complexity and some of the computational results of solving the part families problem are also discussed. 相似文献
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Zhi-Qiang Shao 《Nonlinear Analysis: Theory, Methods & Applications》2010,73(3):600-613
This paper is concerned with the asymptotic behavior of global classical solutions of diagonalizable quasilinear hyperbolic systems with linearly degenerate characteristic fields. On the basis of the existence result for the global classical solution, we prove that when t tends to the infinity, the solution approaches a combination of C1 traveling wave solutions, provided that the C1 norm and the BV norm of the initial data are bounded but possibly large. In contrast to former results obtained by Liu and Zhou [J. Liu, Y. Zhou, Asymptotic behaviour of global classical solutions of diagonalizable quasilinear hyperbolic systems, Math. Methods Appl. Sci. 30 (2007) 479-500], ours do not require their assumption that the system is rich in the sense of Serre. Applications include that to the one-dimensional Born-Infeld system arising in string theory and high energy physics. 相似文献
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Wenrong DAI 《数学年刊B辑(英文版)》2006,27(3):263-286
In this paper, we study the asymptotic behavior of global classical solutions of the Cauchy problem for general quasilinear hyperbolic systems with constant multiple and weakly linearly degenerate characteristic fields. Based on the existence of global classical solution proved by Zhou Yi et al., we show that, when t tends to infinity, the solution approaches a combination of C1 travelling wave solutions, provided that the total variation and the L1 norm of initial data are sufficiently small. 相似文献
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《Journal of Pure and Applied Algebra》2023,227(2):107180
A silting theorem was established by Buan and Zhou as a generalisation of the classical tilting theorem of Brenner and Butler. In this paper, we give an alternative proof of the theorem by using differential graded algebras. 相似文献
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We present a simple and unified technique to establish convergence of various minimization methods. These contain the (conceptual) proximal point method, as well as implementable forms such as bundle algorithms, including the classical subgradient relaxation algorithm with divergent series.An important research work of Phil Wolfe's concerned convex minimization. This paper is dedicated to him, on the occasion of his 65th birthday, in appreciation of his creative and pioneering work. 相似文献
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Yichao YeLihong Wang Zhaowei ChangJingsong He 《Applied mathematics and computation》2011,218(5):2200-2209
In this paper, an efficient algorithm of logarithmic transformation to Hirota bilinear form of the KdV-type bilinear equation is established. In the algorithm, some properties of Hirota operator and logarithmic transformation are successfully applied, which helps to prove that the linear terms of the nonlinear partial differential equation play a crucial role in finding the Hirota bilinear form. Experimented with various integro-differential equations, our algorithm is proven to be more efficient than the algorithm referred by Zhou, Fu, and Li in getting the Hirota bilinear form, especially in achieving the coefficient of the logarithmic transformation. 相似文献
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An iterative method for finding the largest eigenvalue of a nonnegative tensor was proposed by Ng, Qi, and Zhou in 2009. In this paper, we establish an explicit linear convergence rate of the Ng–Qi–Zhou method for essentially positive tensors. Numerical results are given to demonstrate linear convergence of the Ng–Qi–Zhou algorithm for essentially positive tensors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献