A CUBIC SYSTEM WITH 8 SMALL-AMPLITUDE LIMIT-CYCLES

被引:14
作者
NING, SC
MA, SL
KWEK, KH
ZHENG, ZM
机构
[1] BEIJING UNIV AERONAUT & ASTRON,DEPT COMP SCI,BEIJING 100083,PEOPLES R CHINA
[2] NATL UNIV SINGAPORE,DEPT MATH,SINGAPORE 0511,SINGAPORE
[3] BEIJING UNIV,DEPT MATH,BEIJING 100871,PEOPLES R CHINA
基金
美国国家科学基金会;
关键词
LIMIT CYCLES; FINE FOCUS; PERTURBATION; SYMBOLIC COMPUTATION; ORDERING;
D O I
10.1016/0893-9659(94)90005-1
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In E.M. James and N.G. Lloyd's paper A Cubic System with Eight Small-Amplitude Limit Cycles [1], a set of conditions is given that ensures the origin to be a fine focus of order eight and eight limit cycles to bifurcate from the origin by perturbing parameters. We find that one of the conditions, a9 = sigma*a7, where 666/97 < sigma* < 103/15, can be weakened as a9 = sigma.a7 or a9 = sigma1a7, where 283/125 < sigma1 < 284/125. In [1], deriving above conditions is reduced to finding the real solutions of a system of some algebraic equations and inequalities. When verifying these conditions by solving this system in a different ordering, we find another real solution to the system, which is leading to above improvement of the conditions.
引用
收藏
页码:23 / 27
页数:5
相关论文
共 5 条
[1]  
BUCHBERGER B, 1985, RECENT TRENDS MULTID
[2]  
CHAR BW, 1991, MAPLE V LIBRARY REFE
[3]   A CUBIC SYSTEM WITH 8 SMALL-AMPLITUDE LIMIT-CYCLES [J].
JAMES, EM ;
LLOYD, NG .
IMA JOURNAL OF APPLIED MATHEMATICS, 1991, 47 (02) :163-171
[4]  
WU WJ, 1986, KEXUE TONGBAO, V31, P1
[5]  
ZOLADEK H, 1993, SOLUTION CTR FOCUS P