In order to improve the performance of peer-to-peer files sharing system under mobile distributed en-vironments,a novel always-optimally-coordinated(AOC)criterion and corresponding candidate selectionalgorithm are pro...In order to improve the performance of peer-to-peer files sharing system under mobile distributed en-vironments,a novel always-optimally-coordinated(AOC)criterion and corresponding candidate selectionalgorithm are proposed in this paper.Compared with the traditional min-hops criterion,the new approachintroduces a fuzzy knowledge combination theory to investigate several important factors that influence filestransfer success rate and efficiency .Whereas the min-hops based protocols only ask the nearest candidatepeer for desired files,the selection algorithm based on AOC comprehensively considers users' preferencesand network requirements with flexible balancing rules.Furthermore,its advantage also expresses in theindependence of specified resource discovering protocols,allowing for scalability.The simulation resultsshow that when using the AOC based peer selection algorithm,system performance is much better thanthe min-hops scheme,with files successful transfer rate improved more than 50% and transfer time re-duced at least 20%.展开更多
A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed a...A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed algorithm was tested by creating a P2P simulator and varying the input parameters, and was compared to the search algorithms using flooding （FLD） and random walk （RW）. The result shows that with the proposed design, the queries are muted effectively, the network flows are reduced remarkably, and the peer-to-peer file sharing system gains a good expansibility.展开更多
The development of intelligent algorithms for controlling autonomous mobile robots in real-time activities has increased dramatically in recent years.However,conventional intelligent algorithms currently fail to accur...The development of intelligent algorithms for controlling autonomous mobile robots in real-time activities has increased dramatically in recent years.However,conventional intelligent algorithms currently fail to accurately predict unexpected obstacles involved in tour paths and thereby suffer from inefficient tour trajectories.The present study addresses these issues by proposing a potential field integrated pruned adaptive resonance theory(PPART)neural network for effectively managing the touring process of autonomous mobile robots in real-time.The proposed system is implemented using the AlphaBot platform,and the performance of the system is evaluated according to the obstacle prediction accuracy,path detection accuracy,time-lapse,tour length,and the overall accuracy of the system.The proposed system provide a very high obstacle prediction accuracy of 99.61%.Accordingly,the proposed tour planning design effectively predicts unexpected obstacles in the environment and thereby increases the overall efficiency of tour navigation.展开更多
A multi-user view file system (MUVFS) and a security scheme are developed to improve the security of the united storage network (USN) that integrates a network attached storage (NAS) and a storage area network (SAN). ...A multi-user view file system (MUVFS) and a security scheme are developed to improve the security of the united storage network (USN) that integrates a network attached storage (NAS) and a storage area network (SAN). The MUVFS offers a storage volume view for each authorized user who can access only the data in his own storage volume, the security scheme enables all users to encrypt and decrypt the data of their own storage view at client-side, and the USN server needs only to check the users’ identities and the data’s integrity. Experiments were performed to compare the sequential read, write and read/write rates of NFS+MUVFS+secure_module with those of NFS. The results indicate that the security of the USN is improved greatly with little influence on the system performance when the MUVFS and the security scheme are integrated into it.展开更多
基金supported by the National Nature Science Foundation of China(No.60672124)the National High Technology Research and Development Programme the of China(No.2007AA01Z221)
文摘In order to improve the performance of peer-to-peer files sharing system under mobile distributed en-vironments,a novel always-optimally-coordinated(AOC)criterion and corresponding candidate selectionalgorithm are proposed in this paper.Compared with the traditional min-hops criterion,the new approachintroduces a fuzzy knowledge combination theory to investigate several important factors that influence filestransfer success rate and efficiency .Whereas the min-hops based protocols only ask the nearest candidatepeer for desired files,the selection algorithm based on AOC comprehensively considers users' preferencesand network requirements with flexible balancing rules.Furthermore,its advantage also expresses in theindependence of specified resource discovering protocols,allowing for scalability.The simulation resultsshow that when using the AOC based peer selection algorithm,system performance is much better thanthe min-hops scheme,with files successful transfer rate improved more than 50% and transfer time re-duced at least 20%.
文摘A new routing algorithm of peer-to-peer file sharing system with routing indices was proposed, in which a node forwards a query to neighbors that are more likely to have answers based on its statistics. The proposed algorithm was tested by creating a P2P simulator and varying the input parameters, and was compared to the search algorithms using flooding （FLD） and random walk （RW）. The result shows that with the proposed design, the queries are muted effectively, the network flows are reduced remarkably, and the peer-to-peer file sharing system gains a good expansibility.
文摘The development of intelligent algorithms for controlling autonomous mobile robots in real-time activities has increased dramatically in recent years.However,conventional intelligent algorithms currently fail to accurately predict unexpected obstacles involved in tour paths and thereby suffer from inefficient tour trajectories.The present study addresses these issues by proposing a potential field integrated pruned adaptive resonance theory(PPART)neural network for effectively managing the touring process of autonomous mobile robots in real-time.The proposed system is implemented using the AlphaBot platform,and the performance of the system is evaluated according to the obstacle prediction accuracy,path detection accuracy,time-lapse,tour length,and the overall accuracy of the system.The proposed system provide a very high obstacle prediction accuracy of 99.61%.Accordingly,the proposed tour planning design effectively predicts unexpected obstacles in the environment and thereby increases the overall efficiency of tour navigation.
文摘A multi-user view file system (MUVFS) and a security scheme are developed to improve the security of the united storage network (USN) that integrates a network attached storage (NAS) and a storage area network (SAN). The MUVFS offers a storage volume view for each authorized user who can access only the data in his own storage volume, the security scheme enables all users to encrypt and decrypt the data of their own storage view at client-side, and the USN server needs only to check the users’ identities and the data’s integrity. Experiments were performed to compare the sequential read, write and read/write rates of NFS+MUVFS+secure_module with those of NFS. The results indicate that the security of the USN is improved greatly with little influence on the system performance when the MUVFS and the security scheme are integrated into it.
