【摘要】 系统的开放性、网络化给应用系统安全提出了更高的要求。本文基于Ｏｒａｃｌｅ数据库系统的安全特性，讨论了一个数据库应用系统安全框架。更多还原

【Abstract】 The purpose of this paper is to introduce the theory of algorithm of double Beta spline surface by double parameters, the displaying and the projection of three-dimensional freedom surfaces, and the controlling method of automatic selecting scale factor. Appliantion examples are also given.更多还原