1·Through introducing the concept of resource into the traditional RBAC model, a databased-based fine grain RBAC control is implemented.
提出将资源概念引入传统RBAC模型中，实现一种基于数据库的动态细粒度rbac控制。
2·It is based on a database of past PDC bits. In the databased, it includes bit type, average shear stress of well which bit was used in, cost per unit length.
该方法以一个建成的PD C钻头使用资料库为基础，该数据库包括钻头型号、所钻井段地层的平均剪切强度、单位进尺钻井成本等指标。