Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have no...Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.展开更多
Content-based routing（CBR） publish/subscribe（P/S） system is an important class of distributed systems.This system differs from classical paradigms as messages are routed based on their content rather than their de...Content-based routing（CBR） publish/subscribe（P/S） system is an important class of distributed systems.This system differs from classical paradigms as messages are routed based on their content rather than their destination address,so as to provide a fine-granularity event dissemination,and support more flexibility decoupling applications.Covering-based routing is a typical optimization method of CBR and has been widely used as a building block in many distributed P/S systems,for it maintains a compact routing table and reduces the costs of communications and matching computations.So far as we know,this optimization method can only be implemented on acyclic overlay network,but cannot be directly utilized on cyclic networks.As the CBR in cyclic systems becomes a new focus of research,developing covering-based protocols and algorithms for cyclic P/S system is becoming significantly important.This paper contributes the cyclic covering-based routing protocol with corresponding algorithms to support covering-based protocol in cyclic P/S system,and implements it in PADRES,a distributed event management infrastructure based on the publish/subscribe model.展开更多
基金supported by National Natural Science Foundation of China under Grant No. 60873077/F020107the Science Research Project of Zhangzhou Normal University under Grant No. SK09002
文摘Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.
基金supported by the National Natural Science Foundation of China under Grant Nos.61070027,60752001the National Basic Research 973 Program of China under Grant No.2007CB310805+3 种基金the National High-Tech Research and Development 863 Program of China under Grant No.2006AA01A106the Beijing Science and Technology Plan Projects under Grant No.Z09000100960907the Beijing Natural Science Foundation under Grant No.4092043the Co-Building Program of Beijing Municipal Education Commission
文摘Content-based routing（CBR） publish/subscribe（P/S） system is an important class of distributed systems.This system differs from classical paradigms as messages are routed based on their content rather than their destination address,so as to provide a fine-granularity event dissemination,and support more flexibility decoupling applications.Covering-based routing is a typical optimization method of CBR and has been widely used as a building block in many distributed P/S systems,for it maintains a compact routing table and reduces the costs of communications and matching computations.So far as we know,this optimization method can only be implemented on acyclic overlay network,but cannot be directly utilized on cyclic networks.As the CBR in cyclic systems becomes a new focus of research,developing covering-based protocols and algorithms for cyclic P/S system is becoming significantly important.This paper contributes the cyclic covering-based routing protocol with corresponding algorithms to support covering-based protocol in cyclic P/S system,and implements it in PADRES,a distributed event management infrastructure based on the publish/subscribe model.
