This paper describes the problem of doing description logic （DL） reasoning with partially closed world. The issue was addressed by extending the syntax of DL SROIQ with an NBox, which specifies the predicates to clo...This paper describes the problem of doing description logic （DL） reasoning with partially closed world. The issue was addressed by extending the syntax of DL SROIQ with an NBox, which specifies the predicates to close, extending the semantics with the idea of negation as failure, reducing the closed world reasoning to incremental reasoning on classical DL ontologies, and applying the syntactic approximation technology to improve the reasoning performance. Compared with the existing DBox approach, which corresponds to the relation database, the NBox approach supports deduction on closed concepts and roles. Also, the approximate reasoning can reduce reasoning complexity from N2EXPTIME-complete to PTIME-complete while preserving the correctness of reasoning for ontologies with certain properties.展开更多
In this paper, the relationship between argumentation and closed world reasoning for disjunctive information is studied. In particular, the authors propose a simple and intuitive generalization of the closed world ass...In this paper, the relationship between argumentation and closed world reasoning for disjunctive information is studied. In particular, the authors propose a simple and intuitive generalization of the closed world assumption (CWA) for general disjunctive deductive databases (with default negation). This semantics, called DCWA, allows a natural argumentation-based interpretation and can be used to represent reasoning for disjunctive information. We compare DCWA with GCWA and prove that DCWA extends Minker's GCWA to the class of disjunctive databases with default negation. Also we compare our semantics with some related approaches. In addition, the computational complexity of DCWA is investigated.展开更多
In this paper, we introduce a notion of the family of closed world assumptions and compare several well-known closed world approaches in the family to the extent to which an incomplete database is com- pleted.
It is well-known that there are circumstances where applying Reiter's closed world assump- tion (CWA) will lead to logical inconsistencies . In this paper, a new characterization of the CWA consistency is pesented...It is well-known that there are circumstances where applying Reiter's closed world assump- tion (CWA) will lead to logical inconsistencies . In this paper, a new characterization of the CWA consistency is pesented and an algorithm is proposed for determining whether a datalase with- out function symbols is consistent with the CWA. The algorithm is shown to be efficient.展开更多
At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissi...At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and errors.Quality assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same time.Therefore,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge graph.Among them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among entities.In this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness assumptions.The purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.展开更多
基金Supported by the European Project Marrying Ontologies and Soft-ware Technologies (MOST,EUICT 2008-216691)
文摘This paper describes the problem of doing description logic （DL） reasoning with partially closed world. The issue was addressed by extending the syntax of DL SROIQ with an NBox, which specifies the predicates to close, extending the semantics with the idea of negation as failure, reducing the closed world reasoning to incremental reasoning on classical DL ontologies, and applying the syntactic approximation technology to improve the reasoning performance. Compared with the existing DBox approach, which corresponds to the relation database, the NBox approach supports deduction on closed concepts and roles. Also, the approximate reasoning can reduce reasoning complexity from N2EXPTIME-complete to PTIME-complete while preserving the correctness of reasoning for ontologies with certain properties.
基金the National Natural Science Foundation of China (No.69883008,No.69773027), and in part by the NKBRSF of China (No.1999032704)
文摘In this paper, the relationship between argumentation and closed world reasoning for disjunctive information is studied. In particular, the authors propose a simple and intuitive generalization of the closed world assumption (CWA) for general disjunctive deductive databases (with default negation). This semantics, called DCWA, allows a natural argumentation-based interpretation and can be used to represent reasoning for disjunctive information. We compare DCWA with GCWA and prove that DCWA extends Minker's GCWA to the class of disjunctive databases with default negation. Also we compare our semantics with some related approaches. In addition, the computational complexity of DCWA is investigated.
文摘In this paper, we introduce a notion of the family of closed world assumptions and compare several well-known closed world approaches in the family to the extent to which an incomplete database is com- pleted.
文摘It is well-known that there are circumstances where applying Reiter's closed world assump- tion (CWA) will lead to logical inconsistencies . In this paper, a new characterization of the CWA consistency is pesented and an algorithm is proposed for determining whether a datalase with- out function symbols is consistent with the CWA. The algorithm is shown to be efficient.
基金supported by the National Key Laboratory for Complex Systems Simulation Foundation(6142006190301)。
文摘At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and errors.Quality assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same time.Therefore,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge graph.Among them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among entities.In this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness assumptions.The purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.
