FEASIBILITY OF THE REICH PROCEDURE IN THE DECOMPOSITION OF PLANE QUASICONFORMAL MAPPINGS

ＦＥＡＳＩＢＩＬＩＴＹＯＦＴＨＥＲＥＩＣＨＰＲＯＣＥＤＵＲＥＩＮＴＨＥＤＥＣＯＭＰＯＳＩＴＩＯＮＯＦＰＬＡＮＥＱＵＡＳＩＣＯＮＦＯＲＭＡＬＭＡＰＰＩＮＧＳ￥ＬＡＩＷＡＮＣＡＩ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ，ＨｕａＱｉａ...     

基于非协调元的区域分解法──强重迭情形

基于非协调元的区域分解法──强重迭情形黄建国（上海交通大学应用数学系）ＡＤＯＭＡＩＮＤＥＣＯＭＰＯＳＩＴＩＯＮＭＥＴＨＯＤＦＯＲＮＯＮＣＯＮＦＯＲＭＩＮＧＦＩＮＩＴＥＥＬＥＭＥＮＴ──ＴＨＥＣＡＳＥＯＦＳＴＲＯＮＧＯＶＥＲＬＡＰ￥ＨｕａｎｇＪｉａｎ...     

基于非协调元的区域分解法──强重迭情形

基于非协调元的区域分解法──强重迭情形黄建国（上海交通大学应用数学系）ＡＤＯＭＡＩＮＤＥＣＯＭＰＯＳＩＴＩＯＮＭＥＴＨＯＤＦＯＲＮＯＮＣＯＮＦＯＲＭＩＮＧＦＩＮＩＴＥＥＬＥＭＥＮＴ──ＴＨＥＣＡＳＥＯＦＳＴＲＯＮＧＯＶＥＲＬＡＰ￥ＨｕａｎｇＪｉａｎ...     

A PDE PROBLEM ARSING FROM CALCULATION OF THE MODEL FOR CONTINUOUS CASTING OF STEEL

ＡＰＤＥＰＲＯＢＬＥＭＡＲＳＩＮＧＦＲＯＭＣＡＬＣＵＬＡＴＩＯＮＯＦＴＨＥＭＯＤＥＬＦＯＲＣＯＮＴＩＮＵＯＵＳＣＡＳＴＩＮＧＯＦＳＴＥＥＬ￥ＪＩＡＮＧＬＩＳＨＡＮＧ；ＬＩＵＺＵＨＡＮ；ＹＩＦＡＨＵＡＩ；ＡＮＤＹＵＥＸＩＮＧＹＥＡｂｓｔｒａｃｔ：Ｔｈｉ...     

ON A PAIR OF NON-ISOMETRIC ISOSPECTRAL DOMAINS WITH FRACTAL BOUNDARIES AND THE WEYL-BERRY CONJECTURE

ＯＮＡＰＡＩＲＯＦＮＯＮＩＳＯＭＥＴＲＩＣＩＳＯＳＰＥＣＴＲＡＬＤＯＭＡＩＮＳＷＩＴＨＦＲＡＣＴＡＬＢＯＵＮＤＡＲＩＥＳＡＮＤＴＨＥＷＥＹＬＢＥＲＲＹＣＯＮＪＥＣＴＵＲＥＳＬＥＥＭＡＮ，Ｂ．Ｄ．ＣＨＥＮＨＵＡＭａｎｕｓｃｒｉｐｔｒｅｃ...     

THE NON－EXISTENCE OF PERIODIC SOLUTIONS OF A CERTAIN CLASS OF N－TH ORDER DIFFERENTIAL EQUATIONS

ＴＨＥ　ＮＯＮ－ＥＸＩＳＴＥＮＣＥ　ＯＦ　ＰＥＲＩＯＤＩＣ　ＳＯＬＵＴＩＯＮＳ　ＯＦ　Ａ　ＣＥＲＴＡＩＮ　ＣＬＡＳＳ　ＯＦ　Ｎ－ＴＨ　ＯＲＤＥＲ　ＤＩＦＦＥＲＥＮＴＩＡＬ　ＥＱＵＡＴＩＯＮＳＴＨＥＮＯＮ－ＥＸＩＳＴＥＮＣＥＯＦＰＥＲＩＯＤＩＣＳＯＬＵ...     

HOPF BIFURCATION AND OTHER DYNAMICAL BEHAVIORS FOR A FOURTH ORDER DIFFERENTIAL EQUATION IN MODELS OF INFECTIOUS DISEASE

ＨＯＰＦＢＩＦＵＲＣＡＴＩＯＮＡＮＤＯＴＨＥＲＤＹＮＡＭＩＣＡＬＢＥＨＡＶＩＯＲＳＦＯＲＡＦＯＵＲＴＨＯＲＤＥＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＩＮＭＯＤＥＬＳＯＦＩＮＦＥＣＴＩＯＵＳＤＩＳＥＡＳＥＪＩＮＧＺＨＵＪＵＮ（井竹君）（Ｉｎｓｔｉｔ...     

ANALYSES FOR A MATHEMATICAL MODEL OF THE PATTERN FORMATION ON SHELLS OF MOLLUSCS

ＡＮＡＬＹＳＥＳＦＯＲＡＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＴＨＥＰＡＴＴＥＲＮＦＯＲＭＡＴＩＯＮＯＮＳＨＥＬＬＳＯＦＭＯＬＬＵＳＣＳＭＥＩＭＩＮＧＡＮＤＸＩＡＯＹＩＮＧＫＵＮＡｂｓｔｒａｃｔ：Ｔｈｉｓｐａｐｅｒａｎａｌｙｓｅｓａｍａｔｈｅｍａｔｉ...     

LOCAL EXISTENCE THEOREM FOR FIRST ORDER SEMILINEAR HYPERBOLIC SYSTEMS IN SEVERAL SPACE DIMENSIONS

ＬＯＣＡＬＥＸＩＳＴＥＮＣＥＴＨＥＯＲＥＭＦＯＲＦＩＲＳＴＯＲＤＥＲＳＥＭＩＬＩＮＥＡＲＨＹＰＥＲＢＯＬＩＣＳＹＳＴＥＭＳＩＮＳＥＶＥＲＡＬＳＰＡＣＥＤＩＭＥＮＳＩＯＮＳＺＨＯＵＹＩＡｂｓｔｒａｃｔＴｈｉｓｐａｐｅｒｓｔｕｄｉｅｓｆｉｒｓｔｏｒｄｅ...     

THE DISCRETE DYNAMICS FOR COMPETITIVE POPULATIONS OF LOTKA-VOLTERRA TYPE

ＴＨＥＤＩＳＣＲＥＴＥＤＹＮＡＭＩＣＳＦＯＲＣＯＭＰＥＴＩＴＩＶＥＰＯＰＵＬＡＴＩＯＮＳＯＦＬＯＴＫＡ－ＶＯＬＴＥＲＲＡＴＹＰＥＬＩＵＬＡＩＦＵＡＮＤＧＯＮＧＢＩＮＡｂｓｔｒａｃｔ：Ｔｈｅｄｉｓｃｒｅｔｅｄｙｎａｍｉｃｓｆｏｒｃｏｍｐｅｔｉｔｉｏｎｐ...     

对称正定矩阵的多级迭代法

本文主要研究解对称正定矩阵的多级迭代法,并对其收敛性进行证明。最后用数值实验验证此方法的有效性．多级迭代法特别适用于并行计算,并且可以被理解为古典迭代法的扩展,或共轭梯度法的预处理子。     

Finding roots of a real polynomial simultaneously by means of Bairstow's method

Aberth's method for finding the roots of a polynomial was shown to be robust. However, complex arithmetic is needed in this method even if the polynomial is real, because it starts with complex initial approximations. A novel method is proposed for real polynomials that does not require any complex arithmetic within iterations. It is based on the observation that Aberth's method is a systematic use of Newton's method. The analogous technique is then applied to Bairstow's procedure in the proposed method. As a result, the method needs half the computations per iteration than Aberth's method. Numerical experiments showed that the new method exhibited a competitive overall performance for the test polynomials.     

FMT问题的两种三Ⅰ算法及其还原性

进一步研究FMT问题,得到该问题的三Ⅰ算法的一般计算公式,提出该问题的一种新算法三Ⅰ^*算法,给出新算法的一般计算公式,讨论两种算法的还原性问题,明确两种还原性的含义,证明FMT问题的三Ⅰ算法是W－还原的,而三Ⅰ^*算法是Z－还原的。     

Accelerated Imaginary-time Evolution Methods for the Computation of Solitary Waves

Two accelerated imaginary-time evolution methods are proposed for the computation of solitary waves in arbitrary spatial dimensions. For the first method (with traditional power normalization), the convergence conditions as well as conditions for optimal accelerations are derived. In addition, it is shown that for nodeless solitary waves, this method converges if and only if the solitary wave is linearly stable. The second method is similar to the first method except that it uses a novel amplitude normalization. The performance of these methods is illustrated on various examples. It is found that while the first method is competitive with the Petviashvili method, the second method delivers much better performance than the first method and the Petviashvili method.     

A NEW STEPSIZE FOR THE STEEPEST DESCENT METHOD

The steepest descent method is the simplest gradient method for optimization. It is well known that exact line searches along each steepest descent direction may converge very slowly. An important result was given by Barzilar and Borwein, which is proved to be superlinearly convergent for convex quadratic in two dimensional space, and performs quite well for high dimensional problems. The BB method is not monotone, thus it is not easy to be generalized for general nonlinear functions unless certain non-monotone techniques being applied. Therefore, it is very desirable to find stepsize formulae which enable fast convergence and possess the monotone property. Such a stepsize αk for the steepest descent method is suggested in this paper. An algorithm with this new stepsize in even iterations and exact line search in odd iterations is proposed. Numerical results are presented, which confirm that the new method can find the exact solution within 3 iteration for two dimensional problems. The new method is very efficient for small scale problems. A modified version of the new method is also presented, where the new technique for selecting the stepsize is used after every two exact line searches. The modified algorithm is comparable to the Barzilar-Borwein method for large scale problems and better for small scale problems.     

求解病态线性方程组的收缩Lanczos方法

Lanczos方法是求解大型线性方程组的常用方法.遗憾的是,在Lanczos过程中通常会发生算法中断或数值不稳定的情况.将给出求解大型对称线性方程组的收缩Lanczos方法,即DLanczos方法.新算法将采用增广子空间技术,在Lanczos过程中向Krylov子空间加入少量绝对值较小的特征值所对应的特征向量进行收缩.数值实验表明,新算法比Lanczos方法收敛速度更快,并且适合求解病态对称线性方程组.     

A Random Numerical Method with Application in Combustion

This paper presents a random numerical method which combines the random vortex method and the random choice method. A random choice method is used for the modeling reaction-diffusion system. The splitting of source terms in two dimensions for the random choice method is tested. A hybrid random vortex method is used for solving the Navier-Stokes equation which governs the fluid motion. With the assumption of incompressibility, the fluid motion can be uncoupled from the chemistry. The method is applied to a flow passing a circular cylinder which is kept cold or heated. In both cases the method demonstrates an ability to resolve turbulent effects on flame front propagation.     

A hybrid method for inverse cavity scattering problem for shape

In this paper, we give a hybrid method to numerically solve the inverse open cavity scattering problem for cavity shape, given the scattered solution on the opening of the cavity. This method is a hybrid between an iterative method and an integral equations method for solving the Cauchy problem. The idea of this hybrid method is simple, the operation is easy, and the computation cost is small. Numerical experiments show the feasibility of this method, even for cases with noise.     

A hybrid inexact Logarithmic-Quadratic Proximal method for nonlinear complementarity problems

Inspired by the Logarithmic-Quadratic Proximal method [A. Auslender, M. Teboulle, S. Ben-Tiba, A logarithmic-quadratic proximal method for variational inequalities, Comput. Optim. Appl. 12 (1999) 31-40], we present a new prediction-correction method for solving the nonlinear complementarity problems. In our method, an intermediate point is produced by approximately solving a nonlinear equation system based on the Logarithmic-Quadratic Proximal method; and the new iterate is obtained by convex combination of the previous point and the one generated by the improved extragradient method at each iteration. The proposed method allows for constant relative errors and this yields a more practical Logarithmic-Quadratic Proximal type method. The global convergence is established under mild conditions. Preliminary numerical results indicate that the method is effective for large-scale nonlinear complementarity problems.     

解线性互补问题的预处理加速模Gauss-Seidel迭代方法

本文提出了解线性互补问题的预处理加速模系Gauss-Seidel迭代方法,当线性互补问题的系统矩阵是M-矩阵时证明了方法的收敛性,并给出了该预处理方法关于原方法的一个比较定理.数值实验显示该预处理迭代方法明显加速了原方法的收敛.