海浪模式MASNUM(marine science and numerical modeling)是我国自主研发的海浪数值模式,该模式已广泛应用于我国海洋防灾减灾、海上交通运输、军事活动保障等方面的海浪预报中.随着提升业务预报精度和气候研究需求的不断增长,高分辨率...海浪模式MASNUM(marine science and numerical modeling)是我国自主研发的海浪数值模式,该模式已广泛应用于我国海洋防灾减灾、海上交通运输、军事活动保障等方面的海浪预报中.随着提升业务预报精度和气候研究需求的不断增长,高分辨率成为海浪模式发展的必由之路.尽管高性能计算机的快速发展为高分辨率数值模式提供了强大的计算能力支持,但当前很多并行数值模式效率还不高,无法获得更高并行加速比,无法提高模式并行效率并缩短运行墙钟时间.结合现代高性能计算机体系结构特点,深入分析MASNUM模式的性能瓶颈,继而有针对性地对其开展并行优化,明显地提升了通信性能、I/O性能和二维剖分负载平衡性,进而提升了MASNUM模式整体并行效率和可扩展规模.这里以串行性能为基准,当扩展规模达到960个CPU核时,改进后版本加速比可达431.5.该研究也为其他数值模式提供了一些可供借鉴的并行优化策略.展开更多
A novel 6-PSS flexible parallel mechanism was presented,which employed wide-range flexure hinges as passive joints.The proposed mechanism features micron level positioning accuracy over cubic centimeter scale workspac...A novel 6-PSS flexible parallel mechanism was presented,which employed wide-range flexure hinges as passive joints.The proposed mechanism features micron level positioning accuracy over cubic centimeter scale workspace.A three-layer back-propagation(BP) neural network was utilized to the kinematics analysis,in which learning samples containing 1 280 groups of data based on stiffness-matrix method were used to train the BP model.The kinematics performance was accurately calculated by using the constructed BP model with 19 hidden nodes.Compared with the stiffness model,the simulation and numerical results validate that BP model can achieve millisecond level computation time and micron level calculation accuracy.The concept and approach outlined can be extended to a variety of applications.展开更多
文摘海浪模式MASNUM(marine science and numerical modeling)是我国自主研发的海浪数值模式,该模式已广泛应用于我国海洋防灾减灾、海上交通运输、军事活动保障等方面的海浪预报中.随着提升业务预报精度和气候研究需求的不断增长,高分辨率成为海浪模式发展的必由之路.尽管高性能计算机的快速发展为高分辨率数值模式提供了强大的计算能力支持,但当前很多并行数值模式效率还不高,无法获得更高并行加速比,无法提高模式并行效率并缩短运行墙钟时间.结合现代高性能计算机体系结构特点,深入分析MASNUM模式的性能瓶颈,继而有针对性地对其开展并行优化,明显地提升了通信性能、I/O性能和二维剖分负载平衡性,进而提升了MASNUM模式整体并行效率和可扩展规模.这里以串行性能为基准,当扩展规模达到960个CPU核时,改进后版本加速比可达431.5.该研究也为其他数值模式提供了一些可供借鉴的并行优化策略.
基金Project(2002AA422260) supported by the National High Technology Research and Development Program of ChinaProject(2011-6) supported by CAST-HIT Joint Program,ChinaProject supported by Harbin Institute of Technology (HIT) Overseas Talents Introduction Program,China
文摘A novel 6-PSS flexible parallel mechanism was presented,which employed wide-range flexure hinges as passive joints.The proposed mechanism features micron level positioning accuracy over cubic centimeter scale workspace.A three-layer back-propagation(BP) neural network was utilized to the kinematics analysis,in which learning samples containing 1 280 groups of data based on stiffness-matrix method were used to train the BP model.The kinematics performance was accurately calculated by using the constructed BP model with 19 hidden nodes.Compared with the stiffness model,the simulation and numerical results validate that BP model can achieve millisecond level computation time and micron level calculation accuracy.The concept and approach outlined can be extended to a variety of applications.
