The paper considers the problem of semantic processing of web documents by designing an approach, which combines extracted semantic document model and domain- related knowledge base. The knowledge base is populated wi...The paper considers the problem of semantic processing of web documents by designing an approach, which combines extracted semantic document model and domain- related knowledge base. The knowledge base is populated with learnt classification rules categorizing documents into topics. Classification provides for the reduction of the dimensio0ality of the document feature space. The semantic model of retrieved web documents is semantically labeled by querying domain ontology and processed with content-based classification method. The model obtained is mapped to the existing knowledge base by implementing inference algorithm. It enables models of the same semantic type to be recognized and integrated into the knowledge base. The approach provides for the domain knowledge integration and assists the extraction and modeling web documents semantics. Implementation results of the proposed approach are presented.展开更多
A new spiral tool path generation algorithm for 5-axis high speed machining is proposed in this paper.Firstly,the voltage contours are calculated to satisfy the machining parameters in the mapping parametric domain by...A new spiral tool path generation algorithm for 5-axis high speed machining is proposed in this paper.Firstly,the voltage contours are calculated to satisfy the machining parameters in the mapping parametric domain by means of the electrostatic field model of partial differential equations.Secondly,the mapping rules are constructed and the machining trajectory is planned out in the standard parametric domain in order to map and generate the spiral trajectory in the corresponding parametric domain.Finally,this trajectory is mapped onto the parametric surface for the obtainment of the spiral tool path.This spiral tool path can realize the machining of complicated parametric surface and trimmed surface without tool retractions.The above-mentioned algorithm has been implemented in several simulations and validated successfully through the actual machining of a complicated cavity.The results indicate that this method is superior to the existing machining methods to realize the high speed machining of the complicate-shaped cavity based on parametric surface and trimmed surface.展开更多
文摘The paper considers the problem of semantic processing of web documents by designing an approach, which combines extracted semantic document model and domain- related knowledge base. The knowledge base is populated with learnt classification rules categorizing documents into topics. Classification provides for the reduction of the dimensio0ality of the document feature space. The semantic model of retrieved web documents is semantically labeled by querying domain ontology and processed with content-based classification method. The model obtained is mapped to the existing knowledge base by implementing inference algorithm. It enables models of the same semantic type to be recognized and integrated into the knowledge base. The approach provides for the domain knowledge integration and assists the extraction and modeling web documents semantics. Implementation results of the proposed approach are presented.
基金supported by the National Program on Key Basic Research Project of China (973 Program) under Grant No.2011CB302400the National Natural Science Foundation of China (NSFC) under Grant Nos.50975274 and 51175479
文摘A new spiral tool path generation algorithm for 5-axis high speed machining is proposed in this paper.Firstly,the voltage contours are calculated to satisfy the machining parameters in the mapping parametric domain by means of the electrostatic field model of partial differential equations.Secondly,the mapping rules are constructed and the machining trajectory is planned out in the standard parametric domain in order to map and generate the spiral trajectory in the corresponding parametric domain.Finally,this trajectory is mapped onto the parametric surface for the obtainment of the spiral tool path.This spiral tool path can realize the machining of complicated parametric surface and trimmed surface without tool retractions.The above-mentioned algorithm has been implemented in several simulations and validated successfully through the actual machining of a complicated cavity.The results indicate that this method is superior to the existing machining methods to realize the high speed machining of the complicate-shaped cavity based on parametric surface and trimmed surface.
