【作者】 钟勇； 秦小麟； 林冬梅；

【Author】 Zhong Yong~(1,2),Qin Xiaolin~2,and Lin Dongmei~1 1(Information and Education Technology Center,Foshan University,Foshan 528000) 2(Institute of Information Science and Technology,Nanjing University of Aeronautics and Astronautics,Nanjng 210016)

【机构】 佛山科学技术学院信息与教育技术中心； 南京航空航天大学信息科学与技术学院；

【摘要】 通过整数限制域的方式引入时态限制域并提出一种基于DBMS的时态授权逻辑模型.该模型基于分层的限制Datalog^（?）,c,并通过时态限制规则保持限制域的求反闭包性,通过授权阻塞规则解决正负授权冲突,因而具有逻辑上的一致性和可行性,能满足DBMS中各类时态授权的需要.最后对授权程序的可评价（evaluation）性、实现算法及其应用做了说明.更多还原

【Abstract】 By expressing temporal constraint domains as integer constraint domains,a temporal authorization model based on DBMS is presented.The model uses stratified constraint Datalog^（?）,c rules as the foundation of its authorization language,which keeps the constraint domain closed under negation by the temporal constraint rule and resolves the conflict of positive and negative authorizations by the authorization blocking rule.So the model has a logical consistency and tractability,which can satisfy the requirements to express temporal factors in the authorization mechanism of DBMS.The closed-form evaluation of the authorization program,implementation algorithm and application of the model are also discussed.更多还原