In order to optimize ontology reasoning, a novel boundary-based modular extraction method is introduced for ontologies in EL^＋＋ description logics. The proposed module extraction method is capable of identifying rel...In order to optimize ontology reasoning, a novel boundary-based modular extraction method is introduced for ontologies in EL^＋＋ description logics. The proposed module extraction method is capable of identifying relevant axioms in an ontology based on the notion of boundaries of symbols, with respect to a given reasoning task. Exactness of the method is ensured by discovering all axioms in the original ontology that may be directly or indirectly relevant to boundaries of symbols used in the reasoning task. Compactness of the method is ensured by boundary partition and intersection operation performed in the process of module extraction. The theoretical foundation and a practical algorithm for computing the proposed axiom-based modules are presented. The proposed algorithm is implemented for the description logic EL^＋＋. Experimental results on realworld ontologies show that, based on the proposed modularization method, the performance of ontology reasoning can be significantly improved.展开更多
The Ryukyu trench-arc system can be divided into two types according to its subduction model. The normal subduction in the northern part of the Philippine Sea plate creates a hinge sedimentary wedge with large deforma...The Ryukyu trench-arc system can be divided into two types according to its subduction model. The normal subduction in the northern part of the Philippine Sea plate creates a hinge sedimentary wedge with large deformation at the collision front, while the oblique subduction in the southern part gives rise to a smaller accretion with small deformation than that in the northern part. The mechanisms that cause the distinction between these two types have been analysed and calculated by using gravity data based on the lithosphere rheology and the stress state of the lithosphere in the subduction boundary. The two types of subduction model are associated with the internal extension in the southern Okinawa Trough and the small extension in the northern part. The difference of the stress state between the two types of subduction model is also manifested in other tectonic features, such as topography, volcanic activity and crust movement. Modeling bathymetric and gravity data from this area suggests that the oblique subduction of low angle, together with smooth geometry of the overlying plate crust, results in small stress released on the south of the trench by the subduction plate. The intraplate faults in the southern Okinawa Trough behind the trench stand in surplus intensive stress. On the other hand, the normal subduction of high angle, together with strong undulation geometry of the overlying crust, results in more intensive stress released in the northern Ryukyu Trench than that in the south. The intraplate faults in the northern Okinawa Trough behind the northern Ryukyu Trench stand in small stress.展开更多
基金The PhD Programs Foundation of Ministry of Education of China(No20096102120037)
文摘In order to optimize ontology reasoning, a novel boundary-based modular extraction method is introduced for ontologies in EL^＋＋ description logics. The proposed module extraction method is capable of identifying relevant axioms in an ontology based on the notion of boundaries of symbols, with respect to a given reasoning task. Exactness of the method is ensured by discovering all axioms in the original ontology that may be directly or indirectly relevant to boundaries of symbols used in the reasoning task. Compactness of the method is ensured by boundary partition and intersection operation performed in the process of module extraction. The theoretical foundation and a practical algorithm for computing the proposed axiom-based modules are presented. The proposed algorithm is implemented for the description logic EL^＋＋. Experimental results on realworld ontologies show that, based on the proposed modularization method, the performance of ontology reasoning can be significantly improved.
文摘The Ryukyu trench-arc system can be divided into two types according to its subduction model. The normal subduction in the northern part of the Philippine Sea plate creates a hinge sedimentary wedge with large deformation at the collision front, while the oblique subduction in the southern part gives rise to a smaller accretion with small deformation than that in the northern part. The mechanisms that cause the distinction between these two types have been analysed and calculated by using gravity data based on the lithosphere rheology and the stress state of the lithosphere in the subduction boundary. The two types of subduction model are associated with the internal extension in the southern Okinawa Trough and the small extension in the northern part. The difference of the stress state between the two types of subduction model is also manifested in other tectonic features, such as topography, volcanic activity and crust movement. Modeling bathymetric and gravity data from this area suggests that the oblique subduction of low angle, together with smooth geometry of the overlying plate crust, results in small stress released on the south of the trench by the subduction plate. The intraplate faults in the southern Okinawa Trough behind the trench stand in surplus intensive stress. On the other hand, the normal subduction of high angle, together with strong undulation geometry of the overlying crust, results in more intensive stress released in the northern Ryukyu Trench than that in the south. The intraplate faults in the northern Okinawa Trough behind the northern Ryukyu Trench stand in small stress.
