它使经济学家分析最佳削减在何处时产生的直觉得以形式化，也是理论学家在思维远足后转向的新开始。
It formalises economists' gut instincts about where the best analytical cuts lie. It is the starting point to which the theorist returns after every ingenious excursion.
提出一套形式化地描述时间特性的模型，使之能够描述带时间特性的授权约束。
A formal model is proposed to describe time character of constraint in this paper.
但是HL7标准的定义还是通过自然语言来描述的，因此我们需要定义一套语言使HL7语言得以语义化和形式化。
But the HL7 was still defined by the natural language, so we need to enables it the formalization and have the mean of the Semantics.
同时，为使高层应用易于对模型进行有效性和一致性检查，采用超图数据结构形式化地定义了上述模型的概念模型。
Besides, in order to facilitate applications to check affectivity and consistency of this model, a formal concept model based on hyper-graph data structure is proposed.
分析了以上两种模型存在的问题，为了使访问控制更灵活，提出了一种基于角色和任务的访问控制模型，并给出了模型的形式化定义、授权约束和在校园网格中的应用。
It puts forwards a new access control mode based on role and task to make access control more flexible. The formalized meaning, restriction and application in school grid are also presented.
这就使得专业技术人员的知识形式化，使一般的技术人员借助于专家系统达到接近专家的技术水平。
This makes formal knowledge of professional and technical personnel, technical personnel in general and the help of expert system technology to achieve close to the expert level.
对角色的授权约束加入空间特性，使之能够形式化描述多个层面的空间职责分离约束，从而适用于无线网络的应用环境。
This paper also extends a role-based authorization constraint model to describe constraints with spatial character on different levels, which is suited for wireless network.
对角色的授权约束加入空间特性，使之能够形式化描述多个层面的空间职责分离约束，从而适用于无线网络的应用环境。
This paper also extends a role-based authorization constraint model to describe constraints with spatial character on different levels, which is suited for wireless network.
应用推荐