A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed ...A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed by a series of primitive features with tree structure,as a form of constructive solid geometry(CSG) tree.The D2 shape distributions of these features were extracted for geometry similarity measurement,and the pose vector and non-disappeared proportion of each leaf node were gained for topology similarity measurement.Based on these,the dissimilarity between the query and the candidate was accessed by level-by-level CSG tree comparisons.With the adjustable weights,our scheme satisfies different comparison emphasis on the geometry or topology similarity.The assessment results from CSG_D2 demonstrate more discriminative than those from D2 in the analysis of precision-recall and similarity matrix.Finally,an experimental search engine is applied for mechanical parts reuse by using CSG_D2,which is convenient for the mechanical design process.展开更多
Built on artificial intelligence, digitalization, and information technologies, the ＂Third Industrial Revolution ＂＂ transforms large-scale assembly lines and flexible manufacturing system with fundamental modern ma...Built on artificial intelligence, digitalization, and information technologies, the ＂Third Industrial Revolution ＂＂ transforms large-scale assembly lines and flexible manufacturing system with fundamental modern manufacturing technologies and features personalized manufacturing, which is enabled by reconfigurable manufacturing system, and quick market response. It is a profound transformation of techno-economic paradigms, imbedded in the technology, management, and institutional systems. As this revolution deepens, it is likely that manufacturing and the manufacturing sector would acquire new definitions. In addition, the resource foundation and factor structure, which are central to the competitiveness of a nation and an enterprise, would perhaps be reconfigured, hence rewriting the landscape of global industrial competition. Under this scenario, the ＂smiling curve ＇＂ which used to portray the economic features of the value chain, may change into a ＂silence curve＂ or even ＂sadness curve ＂. The catching- up pathway of latecomer countries, as predicted by the traditional ＇flying geese model＂, is likely to be blocked, solidifying the division of＂core and periphery countries＂ which is unfavorable to developing countries. Industrial competition between countries would move from competition between enterprises and supply chains to competition in industrial ecosystems, matdng system adaptability and dynamics the key to long-term industrial competitiveness. As an effort to embrace the ＂Third Industrial Revolution＂ and meet the challenges brought by ＂multi-facets competition＂ with developed industrial nations in various links of value chain, in the future China should make appropriate adjustments in its strategies for economic transition and upgrading, global competition, technological innovation, industrial development and information technology.展开更多
(1) G·Takeuti和W.M.Zaring的《公理化集合论导引》第2版(Introduction to Axiomatic Set Theory [2nd ed]),本书以Zermelo-Fraenke的理论为线索全面介绍公理化集合的Godel和Cohen相容性和独立性理论,用这种论述方式介绍,读者能较...(1) G·Takeuti和W.M.Zaring的《公理化集合论导引》第2版(Introduction to Axiomatic Set Theory [2nd ed]),本书以Zermelo-Fraenke的理论为线索全面介绍公理化集合的Godel和Cohen相容性和独立性理论,用这种论述方式介绍,读者能较容易地掌握公理化集合论的基本理论以及其他相关结果,并进入到80年代的许多新的前沿课题。本书1971年初版,1982年第2版对初版作了全面刷新,增添了许多新内容,如Silver机、证明可构造性公理化相容性的结构设计等。本书可作为数理逻辑专业研究生一个学期集合论课程的标准教材。 (2) G·Takeuti和W.M.Zaring的《公理化集合论》(Axiomatic Set Theory)。本书是《公理化集合论导引》展开更多
基金Project(51175287)supported by the National Natural Science Foundation of ChinaProject(2006AA04Z112)supported by National High Technology Research and Development Program of China
文摘A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed by a series of primitive features with tree structure,as a form of constructive solid geometry(CSG) tree.The D2 shape distributions of these features were extracted for geometry similarity measurement,and the pose vector and non-disappeared proportion of each leaf node were gained for topology similarity measurement.Based on these,the dissimilarity between the query and the candidate was accessed by level-by-level CSG tree comparisons.With the adjustable weights,our scheme satisfies different comparison emphasis on the geometry or topology similarity.The assessment results from CSG_D2 demonstrate more discriminative than those from D2 in the analysis of precision-recall and similarity matrix.Finally,an experimental search engine is applied for mechanical parts reuse by using CSG_D2,which is convenient for the mechanical design process.
文摘Built on artificial intelligence, digitalization, and information technologies, the ＂Third Industrial Revolution ＂＂ transforms large-scale assembly lines and flexible manufacturing system with fundamental modern manufacturing technologies and features personalized manufacturing, which is enabled by reconfigurable manufacturing system, and quick market response. It is a profound transformation of techno-economic paradigms, imbedded in the technology, management, and institutional systems. As this revolution deepens, it is likely that manufacturing and the manufacturing sector would acquire new definitions. In addition, the resource foundation and factor structure, which are central to the competitiveness of a nation and an enterprise, would perhaps be reconfigured, hence rewriting the landscape of global industrial competition. Under this scenario, the ＂smiling curve ＇＂ which used to portray the economic features of the value chain, may change into a ＂silence curve＂ or even ＂sadness curve ＂. The catching- up pathway of latecomer countries, as predicted by the traditional ＇flying geese model＂, is likely to be blocked, solidifying the division of＂core and periphery countries＂ which is unfavorable to developing countries. Industrial competition between countries would move from competition between enterprises and supply chains to competition in industrial ecosystems, matdng system adaptability and dynamics the key to long-term industrial competitiveness. As an effort to embrace the ＂Third Industrial Revolution＂ and meet the challenges brought by ＂multi-facets competition＂ with developed industrial nations in various links of value chain, in the future China should make appropriate adjustments in its strategies for economic transition and upgrading, global competition, technological innovation, industrial development and information technology.
文摘(1) G·Takeuti和W.M.Zaring的《公理化集合论导引》第2版(Introduction to Axiomatic Set Theory [2nd ed]),本书以Zermelo-Fraenke的理论为线索全面介绍公理化集合的Godel和Cohen相容性和独立性理论,用这种论述方式介绍,读者能较容易地掌握公理化集合论的基本理论以及其他相关结果,并进入到80年代的许多新的前沿课题。本书1971年初版,1982年第2版对初版作了全面刷新,增添了许多新内容,如Silver机、证明可构造性公理化相容性的结构设计等。本书可作为数理逻辑专业研究生一个学期集合论课程的标准教材。 (2) G·Takeuti和W.M.Zaring的《公理化集合论》(Axiomatic Set Theory)。本书是《公理化集合论导引》
