期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
用函数单调性解非函数题(高一、高二、高三)
1
作者 郑兴明 《数理天地(高中版)》 2003年第3期3-4,共2页
关键词 函数单调性 非函数题 不等式 中学 数学教学 方法
下载PDF
On the Cauchy Problem for a Class of Nonlinear Wave Equations with Damping Term 被引量:2
2
作者 SONGChang-ming KONGDe-xing 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2005年第2期111-120,共10页
The paper concerns with the existence, uniqueness and nonexistence of global solution to the Cauchy problem for a class of nonlinear wave equations with damping term. It proves that under suitable assumptions on nonli... The paper concerns with the existence, uniqueness and nonexistence of global solution to the Cauchy problem for a class of nonlinear wave equations with damping term. It proves that under suitable assumptions on nonlinear the function and initial data the abovementioned problem admits a unique global solution by Fourier transform method. The sufficient conditions of nonexistence of the global solution to the above-mentioned problem are given by the concavity method. 展开更多
关键词 nonlinear wave equation Cauchy problem global solution concavity method
下载PDF
Filter-sequence of quadratic programming method with nonlinear complementarity problem function
3
作者 金中 濮定国 +1 位作者 张宇 蔡力 《Journal of Shanghai University(English Edition)》 CAS 2008年第2期97-101,共5页
A mechanism for proving global convergence in filter-SQP (sequence of quadratic programming) method with the nonlinear complementarity problem (NCP) function is described for constrained nonlinear optimization pro... A mechanism for proving global convergence in filter-SQP (sequence of quadratic programming) method with the nonlinear complementarity problem (NCP) function is described for constrained nonlinear optimization problem.We introduce an NCP function into the filter and construct a new SQP-filter algorithm.Such methods are characterized by their use of the dominance concept of multi-objective optimization,instead of a penalty parameter whose adjustment can be problematic.We prove that the algorithm has global convergence and superlinear convergence rates under some mild conditions. 展开更多
关键词 nonlinear complementarity problem (NCP) function FILTER sequence of quadratic programming (SQP) globalconvergence.
下载PDF
Underground water quality model inversion of genetic algorithm
4
作者 MA Ruijie LI Xin 《Global Geology》 2009年第3期164-167,共4页
The underground water quality model with non-linear inversion problem is ill-posed, and boils down to solving the minimum of nonlinear function. Genetic algorithms are adopted in a number of individuals of groups by i... The underground water quality model with non-linear inversion problem is ill-posed, and boils down to solving the minimum of nonlinear function. Genetic algorithms are adopted in a number of individuals of groups by iterative search to find the optimal solution of the problem, the encoding strings as its operational objective, and achieving the iterative calculations by the genetic operators. It is an effective method of inverse problems of groundwater, with incomparable advantages and practical significances. 展开更多
关键词 underground water quality model INVERSION genetic algorithm genetic operator
下载PDF
A study of nonlinear age-structured population models 被引量:2
5
作者 Syed Tauseef Mohyud-Din A. Waheed M. M. Ra.shidi 《International Journal of Biomathematics》 2016年第6期211-223,共13页
This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified var... This paper presents a novel analysis for the solution of nonlinear age-structured prob- lem which is of extreme importance in biological sciences. The presented model is very useful but quite complicated. Modified variational iteration method (MVIM) coupled with auxiliary parameter is used to cope with the complexity of the model which subse- quently shows better results as compared to some existing results available in literature. Furthermore, an appropriate way is used for the identification of auxiliary parameter by means of residual function. Numerical examples are presented for the analysis of the pro- posed algorithm. Graphical results along with the discussions re-confirm the efficiency of proposed algorithm. The work proposes a new algorithm where He's polynomials and an auxiliary parameter are merged with correction functional. The suggested scheme is implemented on nonlinear age-structured population models. Graphs are plotted for the residual function that reflects the accuracy and convergence of the presented algorithm. 展开更多
关键词 Age-structured population models nonlinear problems modified variationaliteration method auxiliary parameter correction functional.
原文传递
Increasing Powers in a Degenerate Parabolic Logistic Equation
6
作者 Jos Francisco RODRIGUES Hugo TAVARES 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2013年第2期277-294,共18页
The purpose of this paper is to study the asymptotic behavior of the positive solutions of the problem tu- △u=au-b(x)up in Ω×R+,u(0)=u0,u(t )| Ω=0, as p→ +∞, where Ω is a bounded domain, and b(x... The purpose of this paper is to study the asymptotic behavior of the positive solutions of the problem tu- △u=au-b(x)up in Ω×R+,u(0)=u0,u(t )| Ω=0, as p→ +∞, where Ω is a bounded domain, and b(x) is a nonnegative function. The authors deduce that the limiting configuration solves a parabolic obstacle problem, and afterwards fully describe its long time behavior. 展开更多
关键词 Parabolic logistic equation Obstacle problem Positive solution Increasing power Subsolution and supersolution
原文传递
A smoothing trust region filter algorithm for nonsmooth least squares problems 被引量:2
7
作者 CHEN XiaoJun DU ShouQiang ZHOU Yang 《Science China Mathematics》 SCIE CSCD 2016年第5期999-1014,共16页
We propose a smoothing trust region filter algorithm for nonsmooth nonconvex least squares problems. We present convergence theorems of the proposed algorithm to a Clarke stationary point or a global minimizer of the ... We propose a smoothing trust region filter algorithm for nonsmooth nonconvex least squares problems. We present convergence theorems of the proposed algorithm to a Clarke stationary point or a global minimizer of the objective function under certain conditions. Preliminary numerical experiments show the efficiency of the proposed algorithm for finding zeros of a system of polynomial equations with high degrees on the sphere and solving differential variational inequalities. 展开更多
关键词 smoothing approximation trust region method filter technique
原文传递
Convergence analysis of projected gradient descent for Schatten-p nonconvex matrix recovery 被引量:2
8
作者 CAI Yun LI Song 《Science China Mathematics》 SCIE CSCD 2015年第4期845-858,共14页
The matrix rank minimization problem arises in many engineering applications. As this problem is NP-hard, a nonconvex relaxation of matrix rank minimization, called the Schatten-p quasi-norm minimization(0 < p <... The matrix rank minimization problem arises in many engineering applications. As this problem is NP-hard, a nonconvex relaxation of matrix rank minimization, called the Schatten-p quasi-norm minimization(0 < p < 1), has been developed to approximate the rank function closely. We study the performance of projected gradient descent algorithm for solving the Schatten-p quasi-norm minimization(0 < p < 1) problem.Based on the matrix restricted isometry property(M-RIP), we give the convergence guarantee and error bound for this algorithm and show that the algorithm is robust to noise with an exponential convergence rate. 展开更多
关键词 low rank matrix recovery nonconvex matrix recovery projected gradient descent restricted isometry property
原文传递
GLOBAL CONVERGENCE OF A CLASS OF SMOOTH PENALTY METHODS FOR SEMI-INFINITE PROGRAMMING
9
作者 Changyu WANG Haiyan ZHANG Fang LIU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第4期769-783,共15页
For the semi-infinite programming (SIP) problem, the authors first convert it into an equivalent nonlinear programming problem with only one inequality constraint by using an integral function, and then propose a sm... For the semi-infinite programming (SIP) problem, the authors first convert it into an equivalent nonlinear programming problem with only one inequality constraint by using an integral function, and then propose a smooth penalty method based on a class of smooth functions. The main feature of this method is that the global solution of the penalty function is not necessarily solved at each iteration, and under mild assumptions, the method is always feasible and efficient when the evaluation of the integral function is not very expensive. The global convergence property is obtained in the absence of any constraint qualifications, that is, any accumulation point of the sequence generated by the algorithm is the solution of the SIP. Moreover, the authors show a perturbation theorem of the method and obtain several interesting results. Furthermore, the authors show that all iterative points remain feasible after a finite number of iterations under the Mangasarian-Fromovitz constraint qualification. Finally, numerical results are given. 展开更多
关键词 Global convergence semi-infinite programming smooth penalty function perturbation function.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部