多项式族左扇区稳定的最大摄动区间

Maximal Perturbation Interval for the Left-Sector Stability of Polynomials

已知多项式（ｉ＝０，１，…，ｎ）为参量ｒ的多项式函数且ｐ（ｓ，０）是左扇区稳定的多项式．本文给出ｒ的最大摄动区间以使对这区间中的所有ｒ，多项式ｐ（ｓ，ｒ）都是左扇区稳定的．

Given polynomials whose coefficients (i=0, 1, ...,n) are polynomial functions of a real variable r, also suppose that p(s, 0) is stable where called the left-sector. This paper gives the maximal perturbation interval(rmin,rmax) of variable r so that the polynomials p(s,r) are D-stable for all (rmin,rmax).