多變數Bernstein多項式的一些性質

碩士 === 輔仁大學 === 數學系研究所 === 98 === It is known that multivariate Bernstein polynomials do not preserve convexity althrough it is true for univariate case. The problem could be fixed if the concept of convexity were gener- alized to axial convexity or polyhedral convexity. We introduce these two notio...

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Bibliographic Details
Main Authors: Li Wan-Yu, 李婉瑜
Other Authors: 楊南屏
Format: Others
Language:en_US
Published: 2010
Online Access:http://ndltd.ncl.edu.tw/handle/23832283059096068638
Description
Summary:碩士 === 輔仁大學 === 數學系研究所 === 98 === It is known that multivariate Bernstein polynomials do not preserve convexity althrough it is true for univariate case. The problem could be fixed if the concept of convexity were gener- alized to axial convexity or polyhedral convexity. We introduce these two notions and show that multivariate Bernstein poly- nomials preserve each of them. On the other hand, multivariate Bernstein operators possess monotonicity if they act on convex or axially convex functions. A simple proof will be given using probabilistic methods. In addition, a large class of multivariate Bernstein-type operators are also monotonic. Examples are given to illustrate the fact.