Due to the fact that semantic role labeling （SRL） is very necessary for deep natural language processing, a method based on conditional random fields （CRFs） is proposed for the SRL task. This method takes shallow ...Due to the fact that semantic role labeling （SRL） is very necessary for deep natural language processing, a method based on conditional random fields （CRFs） is proposed for the SRL task. This method takes shallow syntactic parsing as the foundation, phrases or named entities as the labeled units, and the CRFs model is trained to label the predicates＇ semantic roles in a sentence. The key of the method is parameter estimation and feature selection for the CRFs model. The L-BFGS algorithm was employed for parameter estimation, and three category features： features based on sentence constituents, features based on predicate, and predicate-constituent features as a set of features for the model were selected. Evaluation on the datasets of CoNLL-2005 SRL shared task shows that the method can obtain better performance than the maximum entropy model, and can achieve 80. 43 % precision and 63. 55 % recall for semantic role labeling.展开更多
This paper first introduces attribute expression to describe attribute-based access control policy.Secondly,an access control policy enforcement language named A-XACML （attribute-XACML）is proposed,which is an extens...This paper first introduces attribute expression to describe attribute-based access control policy.Secondly,an access control policy enforcement language named A-XACML （attribute-XACML）is proposed,which is an extension of XACML.A-XACML is used as a simple,flexible way to express and enforce access control policies,especially attribute-based access control policy,in a variety of environments.The language and schema support include data types,functions,and combining logic which allow simple and complex policies to be defined.Finally,a system architecture and application case of user-role assignment is given to show how attribute expressions and A-XACML work in access control policy description and enforcement.The case shows that attribute expression and A-XACML can describe and enforce the complex access control policy in a simple and flexible way.展开更多
A new role hierarchy model for RBAC (role-based access control) is presented and its features are illustrated through examples. Some new concepts such as private permission, public permission and special permission ar...A new role hierarchy model for RBAC (role-based access control) is presented and its features are illustrated through examples. Some new concepts such as private permission, public permission and special permission are introduced, based on the RRA97 model. Some new role-role inheriting forms such as normal inheritance, private inheritance, public inheritance and special-without inheritance are defined. Based on the ideas mentioned, the new role hierarchy model is formulated. It is easier and more comprehensible to describe role-role relationships through the new model than through the traditional ones. The new model is closer to the real world and its mechanism is more powerful. Particularly it is more suitable when used in large-scale role hierarchies.展开更多
To describe and integrate various policies applied in different domains, the definition of the family of OntoRBAC based on the ontology of a general role-based access control （RBAC） policy is proposed, which can sup...To describe and integrate various policies applied in different domains, the definition of the family of OntoRBAC based on the ontology of a general role-based access control （RBAC） policy is proposed, which can support and extend the RBAC96 model. The uniform ontology-based description mechanism of secure policies is applied in OntoRBAC, which can be used to describe different secure policies in distributed systems and integrate policies in semantic level with upper concepts. In addition, some rules have been defined to reason within the OntoRBAC to extend the inference algorithms in ontology, which makes the system accommodate itself to RBAC policies better.展开更多
In enterprise dynamic alliance towards agile manufacturing systems, any group needs to know which activities it must take part in, in what order those activities take place and how many other groups it must interact ...In enterprise dynamic alliance towards agile manufacturing systems, any group needs to know which activities it must take part in, in what order those activities take place and how many other groups it must interact with. The traditional procedural models can’t meet the requirement of the modeling for an enterprise dynamic alliance. In this paper, we use role based models for an enterprise modeling. Role based models group activities into roles, which describe the desired behavior of individual enterprise. We have developed a graphical modeling tool built on Web/DCOM platform according to Petri net theory and role based methodology.展开更多
基金The National Natural Science Foundation of China(No60663004)the PhD Programs Foundation of Ministry of Educa-tion of China (No20050007023)
文摘Due to the fact that semantic role labeling （SRL） is very necessary for deep natural language processing, a method based on conditional random fields （CRFs） is proposed for the SRL task. This method takes shallow syntactic parsing as the foundation, phrases or named entities as the labeled units, and the CRFs model is trained to label the predicates＇ semantic roles in a sentence. The key of the method is parameter estimation and feature selection for the CRFs model. The L-BFGS algorithm was employed for parameter estimation, and three category features： features based on sentence constituents, features based on predicate, and predicate-constituent features as a set of features for the model were selected. Evaluation on the datasets of CoNLL-2005 SRL shared task shows that the method can obtain better performance than the maximum entropy model, and can achieve 80. 43 % precision and 63. 55 % recall for semantic role labeling.
基金The National High Technology Research and Development Program of China(863Program)(No.2007AA01Z445)
文摘This paper first introduces attribute expression to describe attribute-based access control policy.Secondly,an access control policy enforcement language named A-XACML （attribute-XACML）is proposed,which is an extension of XACML.A-XACML is used as a simple,flexible way to express and enforce access control policies,especially attribute-based access control policy,in a variety of environments.The language and schema support include data types,functions,and combining logic which allow simple and complex policies to be defined.Finally,a system architecture and application case of user-role assignment is given to show how attribute expressions and A-XACML work in access control policy description and enforcement.The case shows that attribute expression and A-XACML can describe and enforce the complex access control policy in a simple and flexible way.
文摘A new role hierarchy model for RBAC (role-based access control) is presented and its features are illustrated through examples. Some new concepts such as private permission, public permission and special permission are introduced, based on the RRA97 model. Some new role-role inheriting forms such as normal inheritance, private inheritance, public inheritance and special-without inheritance are defined. Based on the ideas mentioned, the new role hierarchy model is formulated. It is easier and more comprehensible to describe role-role relationships through the new model than through the traditional ones. The new model is closer to the real world and its mechanism is more powerful. Particularly it is more suitable when used in large-scale role hierarchies.
基金The National Natural Science Foundation of China(No60403027)
文摘To describe and integrate various policies applied in different domains, the definition of the family of OntoRBAC based on the ontology of a general role-based access control （RBAC） policy is proposed, which can support and extend the RBAC96 model. The uniform ontology-based description mechanism of secure policies is applied in OntoRBAC, which can be used to describe different secure policies in distributed systems and integrate policies in semantic level with upper concepts. In addition, some rules have been defined to reason within the OntoRBAC to extend the inference algorithms in ontology, which makes the system accommodate itself to RBAC policies better.
文摘In enterprise dynamic alliance towards agile manufacturing systems, any group needs to know which activities it must take part in, in what order those activities take place and how many other groups it must interact with. The traditional procedural models can’t meet the requirement of the modeling for an enterprise dynamic alliance. In this paper, we use role based models for an enterprise modeling. Role based models group activities into roles, which describe the desired behavior of individual enterprise. We have developed a graphical modeling tool built on Web/DCOM platform according to Petri net theory and role based methodology.
