The Geosciences Network(GEON)project has been developing cyberinfrastructure for data sharing in the Earth Science community based on a serviceoriented architecture.The layered architecture consists of Core,Middleware...The Geosciences Network(GEON)project has been developing cyberinfrastructure for data sharing in the Earth Science community based on a serviceoriented architecture.The layered architecture consists of Core,Middleware,and Applications services.Core services provide system-level functions(e.g.user authentication),Middleware services provide generic capabilities(e.g.catalog search),and Application services provide functions that users directly interact with,including applications that are specific to Earth Sciences.The GEON‘service stack’includes a standardized set of these services and the corresponding software modules.The GEON Portal provides Web-based access to these services via a set of portlets.This service-oriented approach has enabled GEON to expand to new partner sites and leverage GEON services for other projects.To facilitate interoperation in a distributed geoinformatics environment,GEON is focusing on standards for distributed search across federated catalogs.展开更多
ne way to speed up the execution of sequential programs is to divide them into concurrent segments and execute such segments in a parallel manner over a distributed computing environment. We argue that the execution s...ne way to speed up the execution of sequential programs is to divide them into concurrent segments and execute such segments in a parallel manner over a distributed computing environment. We argue that the execution speedup primarily depends on the concurrency degree between the identified segments as well as communication overhead between the segments. To guar-antee the best speedup, we have to obtain the maximum possible concurrency degree between the identified segments, taking communication overhead into consideration. Existing code distributor and multi-threading approaches do not fulfill such re-quirements;hence, they cannot provide expected distributability gains in advance. To overcome such limitations, we propose a novel approach for verifying the distributability of sequential object-oriented programs. The proposed approach enables users to see the maximum speedup gains before the actual distributability implementations, as it computes an objective function which is used to measure different distribution values from the same program, taking into consideration both remote and sequential calls. Experimental results showed that the proposed approach successfully determines the distributability of different real-life software applications compared with their real-life sequential and distributed implementations.展开更多
基金This research has been funded by the US National Science Foundation via grants 0225673 and 0744229.
文摘The Geosciences Network(GEON)project has been developing cyberinfrastructure for data sharing in the Earth Science community based on a serviceoriented architecture.The layered architecture consists of Core,Middleware,and Applications services.Core services provide system-level functions(e.g.user authentication),Middleware services provide generic capabilities(e.g.catalog search),and Application services provide functions that users directly interact with,including applications that are specific to Earth Sciences.The GEON‘service stack’includes a standardized set of these services and the corresponding software modules.The GEON Portal provides Web-based access to these services via a set of portlets.This service-oriented approach has enabled GEON to expand to new partner sites and leverage GEON services for other projects.To facilitate interoperation in a distributed geoinformatics environment,GEON is focusing on standards for distributed search across federated catalogs.
文摘ne way to speed up the execution of sequential programs is to divide them into concurrent segments and execute such segments in a parallel manner over a distributed computing environment. We argue that the execution speedup primarily depends on the concurrency degree between the identified segments as well as communication overhead between the segments. To guar-antee the best speedup, we have to obtain the maximum possible concurrency degree between the identified segments, taking communication overhead into consideration. Existing code distributor and multi-threading approaches do not fulfill such re-quirements;hence, they cannot provide expected distributability gains in advance. To overcome such limitations, we propose a novel approach for verifying the distributability of sequential object-oriented programs. The proposed approach enables users to see the maximum speedup gains before the actual distributability implementations, as it computes an objective function which is used to measure different distribution values from the same program, taking into consideration both remote and sequential calls. Experimental results showed that the proposed approach successfully determines the distributability of different real-life software applications compared with their real-life sequential and distributed implementations.
