A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying ove...A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying overlay network in such a way that clusters are evenly distributed and that the peers within the cluster are relatively close to each other. A fluid model is developed to compare the performance of the proposed CBT system with the BitTorrent system, and the result shows that the CBT system can effectively improve the performance of the system. Simulation results also demonstrate that the CBT system improves the system scalabihty and efficiency while retaining the robustness and incentives of the original BitTorrent paradigm.展开更多
Marine cultural landscapes are an important part of cultural landscapes,as a new kind of heritage.With reference to the classification of cultural landscapes,a three-level classification system,composed of the marine ...Marine cultural landscapes are an important part of cultural landscapes,as a new kind of heritage.With reference to the classification of cultural landscapes,a three-level classification system,composed of the marine cultural landscape type,the marine cultural landscape subtype and the marine cultural landscape model was constructed in this study,based on the spatial and regional characteristics of marine history and culture.By the analysis of the effects of natural and humanity factors on the formation of marine cultural landscapes,the system structure of the marine cultural landscapes was divided into three major parts:the physical foundation,the marked material and the recessive material.展开更多
To extract structured data from a web page with customized requirements,a user labels some DOM elements on the page with attribute names.The common features of the labeled elements are utilized to guide the user throu...To extract structured data from a web page with customized requirements,a user labels some DOM elements on the page with attribute names.The common features of the labeled elements are utilized to guide the user through the labeling process to minimize user efforts,and are also utilized to retrieve attribute values.To turn the attribute values into a structured result,the attribute pattern needs to be induced.For this purpose,a space-optimized suffix tree called attribute tree is built to transform the document object model(DOM) tree into a simpler form while preserving its useful properties such as attribute sequence order.The pattern is induced bottom-up on the attribute tree,and is further used to build the structured result.Experiments are conducted and show high performance of our approach in terms of precision,recall and structural correctness.展开更多
基金the National High Technology Research and Development Programme of China(No2004AA104280,2006AA01Z172)
文摘A hierarchical clustered BitTorrent （CBT） system is proposed to improve the file sharing perior-mance of the BitTorrent system, in which peers are grouped into clusters in a large-scale BitTorrent-hke underlying overlay network in such a way that clusters are evenly distributed and that the peers within the cluster are relatively close to each other. A fluid model is developed to compare the performance of the proposed CBT system with the BitTorrent system, and the result shows that the CBT system can effectively improve the performance of the system. Simulation results also demonstrate that the CBT system improves the system scalabihty and efficiency while retaining the robustness and incentives of the original BitTorrent paradigm.
基金supported by the National Natural Science Foundation of China (No. U1609203, 41471004)
文摘Marine cultural landscapes are an important part of cultural landscapes,as a new kind of heritage.With reference to the classification of cultural landscapes,a three-level classification system,composed of the marine cultural landscape type,the marine cultural landscape subtype and the marine cultural landscape model was constructed in this study,based on the spatial and regional characteristics of marine history and culture.By the analysis of the effects of natural and humanity factors on the formation of marine cultural landscapes,the system structure of the marine cultural landscapes was divided into three major parts:the physical foundation,the marked material and the recessive material.
基金Supported by the National High Technology Research and Development Programme of China(No.2009AA01 Z141)the National Natural Science Foundation of China(No.60573117)Beijing Natural Science Foundation(No.4131001)
文摘To extract structured data from a web page with customized requirements,a user labels some DOM elements on the page with attribute names.The common features of the labeled elements are utilized to guide the user through the labeling process to minimize user efforts,and are also utilized to retrieve attribute values.To turn the attribute values into a structured result,the attribute pattern needs to be induced.For this purpose,a space-optimized suffix tree called attribute tree is built to transform the document object model(DOM) tree into a simpler form while preserving its useful properties such as attribute sequence order.The pattern is induced bottom-up on the attribute tree,and is further used to build the structured result.Experiments are conducted and show high performance of our approach in terms of precision,recall and structural correctness.
