According to characteristics of workflow performing,based on task-role-based access control model,this paper advanced rudimental assigned policy of users,load equilibrium of user,separation of duties of user,cardinality constraint of user etc.

This paper expanded task-role-based access control model,advanced some new strategy of user-oriented task assignment and role-oriented privilege assignment,which effectively solved the question of implicative responsibility,user-oriented business task,user-oriented separation of duties,and privilege s assignment.

Based on Role-Based Access Control Model,a new method based on mutually exclusive roles is proposed to implement separation of duties.

Time-based separation of duty;

However,there are some limitations of the dRBAC model,which represent the following issues: no control on the depth of delegation,circular search for delegation chain,covert promotion of role,violating separation of duty.

In the paper,it is mainly discussed about separation of duty in the role-based access control(RBAC)models by means of time,and introduce a simply specification to explain the temporal separation of duty as well as the corresponding enforcement model.

Considering the flexible effect of the harmonic retarders,the style of dynamic constraint of the flexible beam during control was analyzed;then,the modal frequency and vibration shapes related to the control parameters and hamonic retarder s rigidity parameter were obtained.

This paper constructs the fuzzy-valued dynamic constraint concept networks on the theoretical basis of the fuzzy sets and the semantic networks,introduces the basic construction method of this concept network,and puts forward the text analysis algorithm based on the concept network.

On the theoretical basis of the neural networks and the semantic networks,this article constructs the dynamic constraint concept networks,introduces its characteristic of constraint,dynamic and inheritance,and puts forward the model of knowledge retrieval based on the concept networks and the heuristic dynamic retrieval algorithm.