Послідовності функцій і ряди Тейлора з нечітким комплексним аргументом

• Date: 2016
• Main Author: Spectorsky, Igor Ya.
• Format: Article
• Language: Russian
• Published: The National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" 2016
• Subjects: нечітке комплексне число; функціональна послідовність; збіжність
• Online Access: http://journal.iasa.kpi.ua/article/view/59886
• Journal Title: System research and information technologies

This article considers functional sequences ƒn(A) with fuzzy complex number A for an argument. The convergences limn→∞ƒ'n(z)=ƒ(z) and limn→∞ƒ'n(x)=ƒ'(x) are assumed to be uniform inside each circle supp A. Due to analyticity, the conditions of point-wise convergence of derivatives and finiteness of the number of solutions for equation ƒ(z)=w with respect to z for each w inside each circle supp A are satisfied. The paper proposes the sufficient conditions for the convergence ƒn(A) in the sense that the sequence of membership functions μƒn(A)(w) converges point-wise. The convergence limn→∞μƒn(A)(w)=μƒ(A)(w) is proved for all points w∈X, except such w=ƒ(z), that z is a discontinuity point of μA(z), or ƒ'(z)=0. As a particular case of a sequence ƒn(A), the generalization of Taylor series ƒ(z)=∑i=0∞ƒ(i)(z0)/i!(z-z0)i is considered for an analytical function ƒ(z) for the case of fuzzy complex argument z=A. The convergence of the series is considered in the sense of point-wise convergence of the partial sum μSn(A)(w), where Sn(z)=∑i=0∞ƒ(i)(z0)/i!(z-z0)i.