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
Most overlay of existing P2P streaming systems just focus on the view point of video content data.An multi-dimensional overlay for the P2P streaming system(MDOPS) is proposed for providing multi-dimensional view inclu...Most overlay of existing P2P streaming systems just focus on the view point of video content data.An multi-dimensional overlay for the P2P streaming system(MDOPS) is proposed for providing multi-dimensional view including video data,peers' service capability and online stability based on locality sensitive hashing.MDOPS organizes all Live/VoD peers and the above multi-dimensional information in a one-dimensinal DHT,uses range resource information publish/search and introduces multiple load balancing methods.MDOPS maintains an additional candidate coordinating peer list with high qualified peers who own the video data the peer would possibly access currently and in future.This list could speed up the process of searching peers for data scheduling layer.Simulation experiment based on trace of real streaming system has testified that MDOPS can effectively improve the quality of search results and smooth load distribution among peers without increasing the cost of resource publish/search.展开更多
The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,t...The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,the robot moves to three different positions to capture the images of three targets.Then the transformation matrix X between camera and tool center point(TCP) coordinate systems can be calculated by using the known parameters of robot and the extrinsic parameters,and finally the multi-view coordinate system can be transformed into robot coordinate system by the transformation matrix X.With the help of robot,the multi-view point cloud can be easily transformed into a unified coordinate system.By using robot,the measurement doesn't need any mark.Experimental results show that the method is effective.展开更多
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.
基金Supported by the National High Technology Research and Development Programme of China(No.2008AA01A317)the National Natural Science Foundation of China(No.60903218)
文摘Most overlay of existing P2P streaming systems just focus on the view point of video content data.An multi-dimensional overlay for the P2P streaming system(MDOPS) is proposed for providing multi-dimensional view including video data,peers' service capability and online stability based on locality sensitive hashing.MDOPS organizes all Live/VoD peers and the above multi-dimensional information in a one-dimensinal DHT,uses range resource information publish/search and introduces multiple load balancing methods.MDOPS maintains an additional candidate coordinating peer list with high qualified peers who own the video data the peer would possibly access currently and in future.This list could speed up the process of searching peers for data scheduling layer.Simulation experiment based on trace of real streaming system has testified that MDOPS can effectively improve the quality of search results and smooth load distribution among peers without increasing the cost of resource publish/search.
基金supported by the National Natural Science Foundation of China(Nos.60808020 and 61078041)the National Science and Technology Support Program(No.2014BAH03F01)+2 种基金the Tianjin Research Program of Application Foundation and Advanced Technology(No.10JCYBJC07200)the Tianjin Small and Medium Enterprise Innovation Fund(No.12ZXCXGX11800)the Technology Program of Tianjin Municipal Education Commission(No.20130324)
文摘The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,the robot moves to three different positions to capture the images of three targets.Then the transformation matrix X between camera and tool center point(TCP) coordinate systems can be calculated by using the known parameters of robot and the extrinsic parameters,and finally the multi-view coordinate system can be transformed into robot coordinate system by the transformation matrix X.With the help of robot,the multi-view point cloud can be easily transformed into a unified coordinate system.By using robot,the measurement doesn't need any mark.Experimental results show that the method is effective.
