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凸性与度量投影的连续性
Convexity and the Continuity of Metric Projections
【摘要】 本文研究近强凸、近非常凸 Banach空间中度量投影的连续性 .获得如下结果 :若 A是近强凸 (近非常凸 )空间中的逼近凸集 ,则度量投影 PA是范 -范上半连续的(范 -弱上半连续的 ) .此外 ,我们还利用度量投影的连续性给出 Banach空间为近强凸、近非常凸的一些充分必要条件 .
【Abstract】 In this paper, we study the continuity of metric projections in nearly strong convex, nearly very convex Banach spaces. The following results are obtaited: Let A be a proximinal convex subset in a nearly strong convex (nearly very convex) Banach space, then the metric projection P A is norm norm upper semicontinous (norm weak upper semicontinous). Moreover, using the continuity of metric projections, we give some characterization of nearly strong convexity and nearly very convexity.
【关键词】 度量投影;
逼近集;
上半连续;
近强凸;
分离定理;
【Key words】 Metric projection; Proximinal set; Upper semi continuous; Nearly strong convex; Separation theorem;
【Key words】 Metric projection; Proximinal set; Upper semi continuous; Nearly strong convex; Separation theorem;
- 【文献出处】 应用数学 ,Mathematica Applicata , 编辑部邮箱 ,2001年01期
- 【分类号】O177.2
- 【被引频次】24
- 【下载频次】88