基于网络的大规模软件应用系统面临着日益复杂的数据资源安全管理的难题,基于角色的访问控制方法(Role Based Access Control,简称RBAC),实现用户与访问权限的逻辑分离和构造角色之间的层次关系,从而方便了数据的安全管理。基于角色的...基于网络的大规模软件应用系统面临着日益复杂的数据资源安全管理的难题,基于角色的访问控制方法(Role Based Access Control,简称RBAC),实现用户与访问权限的逻辑分离和构造角色之间的层次关系,从而方便了数据的安全管理。基于角色的访问控制的基础,对角色进行进一步划分,分为模块级角色和数据级角色。一个模块级角色包含至少一个或者多个数据级角色。以角色间包含关系取代RBAC中角色之间的继承关系,有效的防止了角色间继承带来的冗余隐患。展开更多
Let A and B be rings and U a(B,A)-bimodule.If BU is flat and UA is finitely generated projective(resp.,BU is finitely generated projective and UA is flat),then the characterizations of level modules and Gorenstein AC-...Let A and B be rings and U a(B,A)-bimodule.If BU is flat and UA is finitely generated projective(resp.,BU is finitely generated projective and UA is flat),then the characterizations of level modules and Gorenstein AC-projective modules(resp.,absolutely clean modules and Gorenstein AC-injective modules)over the formal triangular matrix ring T=(A0 UB)are given.As applications,it is proved that every Gorenstein AC-projective left T-module is projective if and only if each Gorenstein AC-projective left A-module and B-module is projective,and every Gorenstein AC-injective left T-module is injective if and only if each Gorenstein AC-injective left A-module and B-module is injective.Moreover,Gorenstein AC-projective and AC-injective dimensions over the formal triangular matrix ring T are studied.展开更多
文摘基于网络的大规模软件应用系统面临着日益复杂的数据资源安全管理的难题,基于角色的访问控制方法(Role Based Access Control,简称RBAC),实现用户与访问权限的逻辑分离和构造角色之间的层次关系,从而方便了数据的安全管理。基于角色的访问控制的基础,对角色进行进一步划分,分为模块级角色和数据级角色。一个模块级角色包含至少一个或者多个数据级角色。以角色间包含关系取代RBAC中角色之间的继承关系,有效的防止了角色间继承带来的冗余隐患。
基金partly supported by NSF of China(grants 11761047 and 11861043).
文摘Let A and B be rings and U a(B,A)-bimodule.If BU is flat and UA is finitely generated projective(resp.,BU is finitely generated projective and UA is flat),then the characterizations of level modules and Gorenstein AC-projective modules(resp.,absolutely clean modules and Gorenstein AC-injective modules)over the formal triangular matrix ring T=(A0 UB)are given.As applications,it is proved that every Gorenstein AC-projective left T-module is projective if and only if each Gorenstein AC-projective left A-module and B-module is projective,and every Gorenstein AC-injective left T-module is injective if and only if each Gorenstein AC-injective left A-module and B-module is injective.Moreover,Gorenstein AC-projective and AC-injective dimensions over the formal triangular matrix ring T are studied.
