Shortest-path calculation on weighted graphs are an essential operation in computer networks. The performance of such algorithms has become a critical challenge in emerging software-defined networks(SDN),since SDN con...Shortest-path calculation on weighted graphs are an essential operation in computer networks. The performance of such algorithms has become a critical challenge in emerging software-defined networks(SDN),since SDN controllers need to centralizedly perform a shortest-path query for every flow,usually on large-scale network. Unfortunately,one of the challenges is that current algorithms will become incalculable as the network size increases. Therefore, inspired by the compression graph in the field of compute visualization,we propose an efficient shortest path algorithm by compressing the original big network graph into a small one, but the important graph properties used to calculate path is reserved. We implement a centralized version of our approach in SDN-enabled network,and the evaluations validate the improvement compared with the well-known algorithms.展开更多
Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algori...Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algorithms have to scan all the streams of tags in query patterns. However, useless path matches cannot be completely avoided. TJFast which is based on the labeling scheme of Extended Dewey has been proposed to avoid useless intermediate results, and it only needs to access the labels of the leaf query nodes. However, it don＇t concern about the characteristics of elements with the same parent, and it has to merge join all the intermediate results which are evaluated during the first phrase. We propose a new labeling scheme to compress the XML elements which have the same characteristic. Based on the compressed path-labeled streams, a new novel holistic twig query algorithm named CPJoin is designed. Finally, implementation results are provided to show that CPJoin has good performance on both real and synthetic data.展开更多
This paper provides a method of producing a minimum cost spanning tree(MCST)using set operations.It studies the data structure for implementation of set operations and the algorithm to be applied to this structure and...This paper provides a method of producing a minimum cost spanning tree(MCST)using set operations.It studies the data structure for implementation of set operations and the algorithm to be applied to this structure and proves the correctness and the complexity of the algorithm.This algorithm uses the FDG(formula to divide elements into groups)to sort(the FDG sorts a sequence of n elements in expected tir O(n))and uses the method of path compression to find and to unite.Therefore.n produces an MCST of an undirected network having n vertices and e edges in expected time O(eG(n)).展开更多
基金supported by the National Natural Science Foundation of China(No.61521003)
文摘Shortest-path calculation on weighted graphs are an essential operation in computer networks. The performance of such algorithms has become a critical challenge in emerging software-defined networks(SDN),since SDN controllers need to centralizedly perform a shortest-path query for every flow,usually on large-scale network. Unfortunately,one of the challenges is that current algorithms will become incalculable as the network size increases. Therefore, inspired by the compression graph in the field of compute visualization,we propose an efficient shortest path algorithm by compressing the original big network graph into a small one, but the important graph properties used to calculate path is reserved. We implement a centralized version of our approach in SDN-enabled network,and the evaluations validate the improvement compared with the well-known algorithms.
基金Supported by the National Natural Science Foundation of China (60573089)the Teaching and Research Award Program for Out-standing Young Teachers in Post-Secondary Institutions by the Ministry of Education, China (706016)
文摘Holistic twig query processing techniques based on region encoding have been developed to minimize the intermediate results, namely, those root-to-leaf path matches that are not in the final twig results. These algorithms have to scan all the streams of tags in query patterns. However, useless path matches cannot be completely avoided. TJFast which is based on the labeling scheme of Extended Dewey has been proposed to avoid useless intermediate results, and it only needs to access the labels of the leaf query nodes. However, it don＇t concern about the characteristics of elements with the same parent, and it has to merge join all the intermediate results which are evaluated during the first phrase. We propose a new labeling scheme to compress the XML elements which have the same characteristic. Based on the compressed path-labeled streams, a new novel holistic twig query algorithm named CPJoin is designed. Finally, implementation results are provided to show that CPJoin has good performance on both real and synthetic data.
文摘This paper provides a method of producing a minimum cost spanning tree(MCST)using set operations.It studies the data structure for implementation of set operations and the algorithm to be applied to this structure and proves the correctness and the complexity of the algorithm.This algorithm uses the FDG(formula to divide elements into groups)to sort(the FDG sorts a sequence of n elements in expected tir O(n))and uses the method of path compression to find and to unite.Therefore.n produces an MCST of an undirected network having n vertices and e edges in expected time O(eG(n)).
