期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
虚二次域类数的可除性
1
作者 曹珍富 《数学年刊(A辑)》 CSCD 北大核心 2004年第3期397-406,共10页
设正整数d1,d2满足gcd(d1,d2)=1,d=d1d2>3且d1无平方因子,h(d)为虚二次域Q(-d)的类数,这里d1,d2满足下列等式d1a2+d2b2=4kn,gcd(d1a,d2b)=1,a,b,k,n∈N,k>1,n>1,b|*d2,其中符号b|*d2表示b的每个素因子整除d2.本文应用Bilu,Han... 设正整数d1,d2满足gcd(d1,d2)=1,d=d1d2>3且d1无平方因子,h(d)为虚二次域Q(-d)的类数,这里d1,d2满足下列等式d1a2+d2b2=4kn,gcd(d1a,d2b)=1,a,b,k,n∈N,k>1,n>1,b|*d2,其中符号b|*d2表示b的每个素因子整除d2.本文应用Bilu,Hanrot和Vroutier关于本原因子的一个新结果,给出了这类类数问题的完整的解答.同时还给出了广义Ramanujan-Nagell方程的一般性结果。 展开更多
关键词 虚二次域 类数问题 密码问题 广义RAMANUJAN-NAGELL方程 Lucas Lehmer序列
下载PDF
Singular Solutions of the Cauchy Problem for SemilinearParabolic Equations with Singular Potentions
2
作者 曾有栋 陈祖墀 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第1期1-8,共8页
In this paper we consider the Cauchy problem for the singular semilinear parabolic equation u t-Δu+V 1(x)u=V 2(x)u p,x∈R n\{0},t>0, where V 1(x),V 2(x) may have singularities at the origin. Using functions... In this paper we consider the Cauchy problem for the singular semilinear parabolic equation u t-Δu+V 1(x)u=V 2(x)u p,x∈R n\{0},t>0, where V 1(x),V 2(x) may have singularities at the origin. Using functions of the Kato class and the Green tight functions we got the existence of the positive solution being singular at the origin. 展开更多
关键词 SINGULARITY Kato class Green tight function fixed point
下载PDF
A new clustering algorithm for large datasets 被引量:1
3
作者 李清峰 彭文峰 《Journal of Central South University》 SCIE EI CAS 2011年第3期823-829,共7页
The Circle algorithm was proposed for large datasets.The idea of the algorithm is to find a set of vertices that are close to each other and far from other vertices.This algorithm makes use of the connection between c... The Circle algorithm was proposed for large datasets.The idea of the algorithm is to find a set of vertices that are close to each other and far from other vertices.This algorithm makes use of the connection between clustering aggregation and the problem of correlation clustering.The best deterministic approximation algorithm was provided for the variation of the correlation of clustering problem,and showed how sampling can be used to scale the algorithms for large datasets.An extensive empirical evaluation was given for the usefulness of the problem and the solutions.The results show that this method achieves more than 50% reduction in the running time without sacrificing the quality of the clustering. 展开更多
关键词 data mining Circle algorithm clustering categorical data clustering aggregation
下载PDF
Optimality of Vector Optimization Involving Generalized Type-I Functions in Banach 被引量:1
4
作者 QU He-mei XUE Zhen-xia 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第4期543-550,共8页
In this note,new classes of generalized type-I functions are introduced for functions between Banach spaces.These generalized type-I functions are then utilized to establish sufficient optimality conditions and dualit... In this note,new classes of generalized type-I functions are introduced for functions between Banach spaces.These generalized type-I functions are then utilized to establish sufficient optimality conditions and duality results for a vector optimization problem with functions defined on a Banach space. 展开更多
关键词 vector optimization optimality conditions type-I functions duality
下载PDF
Some Planar Graphs with Star Chromatic Number Between Three and Four
5
作者 李德明 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2001年第4期500-504,共5页
We construct sonic infinite family of planar graphs with star chromatic number, where, partially answering a question of Vince,
关键词 (k d)-coloring star chromatic number planar graph
下载PDF
Variable Sets principle and method for flood classification 被引量:23
6
作者 CHEN ShouYu XUE ZhiChun LI Min 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第9期2343-2348,共6页
Flood classification is an effective way to improve flood forecasting accuracy. According to the opposite unity mathematical theorem in Variable Sets theory, this paper proposes a Variable Sets principle and method fo... Flood classification is an effective way to improve flood forecasting accuracy. According to the opposite unity mathematical theorem in Variable Sets theory, this paper proposes a Variable Sets principle and method for flood classification, which is based on the mathematical theorem of dialectics basic laws. This newly proposed method explores a novel way to analyze and solve engineering problems by utilizing a dialectical thinking. In this paper, the Tuwei River basin, located in the Yellow River tributary, is taken as an example for flood classification. The results obtained in this study reveal the problems in a previous method—Set Pair Analysis classification method. The variable sets method is proven to be theoretically rigorous, computationally simple. The classification results are objective, accurate and consistent with the actual situations. This study demonstrates the significant importance of using a scientifically sound method in solving engineering problems. 展开更多
关键词 flood classification Variable Sets opposite unity theorem gradually qualitative change Set Pair Analysis
原文传递
NEW ROBUST UNSUPERVISED SUPPORT VECTOR MACHINES
7
作者 Kun ZHAO Mingyu ZHANG ~ Naiyang DENG 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第3期466-476,共11页
This paper proposes robust version to unsupervised classification algorithm based on modified robust version of primal problem of standard SVMs, which directly relaxes it with label variables to a semi-definite progra... This paper proposes robust version to unsupervised classification algorithm based on modified robust version of primal problem of standard SVMs, which directly relaxes it with label variables to a semi-definite programming. Numerical results confirm the robustness of the proposed method. 展开更多
关键词 ROBUST semi-definite programming support vector machines unsupervised learning
原文传递
GLOBAL CONVERGENCE OF A CLASS OF SMOOTH PENALTY METHODS FOR SEMI-INFINITE PROGRAMMING
8
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