The flexibility of traditional image processing system is limited because those system are designed for specific applications. In this paper, a new TMS320C64x-based multi-DSP parallel computing architecture is present...The flexibility of traditional image processing system is limited because those system are designed for specific applications. In this paper, a new TMS320C64x-based multi-DSP parallel computing architecture is presented. It has many promising characteristics such as powerful computing capability, broad I/O bandwidth, topology flexibility, and expansibility. The parallel system performance is evaluated by practical experiment.展开更多
Peta-scale high-perfomlance computing systems are increasingly built with heterogeneous CPU and GPU nodes to achieve higher power efficiency and computation throughput. While providing unprecedented capabilities to co...Peta-scale high-perfomlance computing systems are increasingly built with heterogeneous CPU and GPU nodes to achieve higher power efficiency and computation throughput. While providing unprecedented capabilities to conduct computational experiments of historic significance, these systems are presently difficult to program. The users, who are domain experts rather than computer experts, prefer to use programming models closer to their domains （e.g., physics and biology） rather than MPI and OpenME This has led the development of domain-specific programming that provides domain-specific programming interfaces but abstracts away some performance-critical architecture details. Based on experience in designing large-scale computing systems, a hybrid programming framework for scientific computing on heterogeneous architectures is proposed in this work. Its design philosophy is to provide a collaborative mechanism for domain experts and computer experts so that both domain-specific knowledge and performance-critical architecture details can be adequately exploited. Two real-world scientific applications have been evaluated on TH-IA, a peta-scale CPU-GPU heterogeneous system that is currently the 5th fastest supercomputer in the world. The experimental results show that the proposed framework is well suited for developing large-scale scientific computing applications on peta-scale heterogeneous CPU/GPU systems.展开更多
A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk ac...A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.展开更多
Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated d...Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated due to aerodynamic interference between highway and railway decks. To study the effects of splitter plates, wind tunnel experiments for measuring VIV and aerostatic forces of twin decks under two opposite flow directions were conducted, while the surrounding flow and wind pressure of static twin decks with and without splitter plates are numerically simulated. The results showed that the incoming flow direction affects the VIV response and aerostatic coefficients. The highway deck has poor vertical and torsional VIV, and the VIV region and amplitude are different under different directions. While the railway deck only has vertical VIV when located upstream. The splitter plates can impede the process of vortex generation, shedding and impinging at the gap between twin deck, and significantly reducing the surface fluctuating pressure coefficient, thus effectively suppressing the VIV of twin decks. While, the splitter plates hurt the upstream deck regarding static wind stability and have little effect on the downstream deck. The splitter plates of appropriate width are recommended to improve VIV performances in twin parallel bridges.展开更多
The grid equations in decomposed domain by parallel computation are soled, and a method of local orthogonalization to solve the large-scaled numerical computation is presented. It constructs preconditioned iteration m...The grid equations in decomposed domain by parallel computation are soled, and a method of local orthogonalization to solve the large-scaled numerical computation is presented. It constructs preconditioned iteration matrix by the combination of predigesting LU decomposition and local orthogonalization, and the convergence of solution is proved. Indicated from the example, this algorithm can increase the rate of computation efficiently and it is quite stable.展开更多
Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more ...Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.展开更多
This paper presents partially asynchronous parallel simulation of continuous-system (PAPSoCS) and some approaches to the issues of its implementation on a multicomputer system. To guarantee the simulation results cor...This paper presents partially asynchronous parallel simulation of continuous-system (PAPSoCS) and some approaches to the issues of its implementation on a multicomputer system. To guarantee the simulation results correct and speedup the simulation, the scheme for efficient PAPSoCS is proposed and the virtual topology star is constructed to match the path of message passing for solving algorithm-architecture adequation problem. Under the circumstances that messages frequently passed inter-processor are much shorter, typically within several 4 bytes, asynchronous communication mode is employed to reduce the communication ratio. Experiment results show that asynchronous parallel simulation has much higher efficiency than its synchronous counterpart.展开更多
In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear...In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear multistep method, which overcomes the defect of the 3rd order parallel Runge-Kutta method discussed in [1].展开更多
Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at t...Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at this problem,a parallelization approach was proposed with six memory optimization schemes for CG,four schemes of them aiming at all kinds of sparse matrix-vector multiplication (SPMV) operation. Conducted on IBM QS20,the parallelization approach can reach up to 21 and 133 times speedups with size A and B,respectively,compared with single power processor element. Finally,the conclusion is drawn that the peak bandwidth of memory access on Cell BE can be obtained in SPMV,simple computation is more efficient on heterogeneous processors and loop-unrolling can hide local storage access latency while executing scalar operation on SIMD cores.展开更多
Based on the efficient hybrid methods for solving initial value problems of stiff ODEs, this paper derives a parallel scheme that can be used to solve the problems on parallel computers with N processors, and discusse...Based on the efficient hybrid methods for solving initial value problems of stiff ODEs, this paper derives a parallel scheme that can be used to solve the problems on parallel computers with N processors, and discusses the iteratively B-convergence of the Newton iterative process, finally, the paper provides some numberical results which show that the parallel scheme is highly efficient as N is not too large.展开更多
Gamma is a kernel programming language with an elegant chemical reaction metaphor in whichprograms are described in terms of multiset rewriting. Gamma formalism allows one to describe analgorithm without introducing a...Gamma is a kernel programming language with an elegant chemical reaction metaphor in whichprograms are described in terms of multiset rewriting. Gamma formalism allows one to describe analgorithm without introducing artificial sequentiality and leads to the derivation of a parallel solution to agiven problem naturally. However, the difficulty of incorporating control strategies makes Gamma not onlyhard for one to define any sophisticated approaches but also impossible to reach a decent level of efficiencyin any direct implementation. Recently, a higherorder multiset programming paradigm, named higher--order Gamma, is introduced by Metayer to alleviate these problems. In this paper, we investigate the possibility of implementing higherorder Gamma on Maspar, a massively data parallel computer. The results showthat a program written in higher--order Gamma can be transformed naturally toward an efficientimplementation on a real parallel machine.展开更多
基金This project was supported by the National Natural Science Foundation of China (60135020).
文摘The flexibility of traditional image processing system is limited because those system are designed for specific applications. In this paper, a new TMS320C64x-based multi-DSP parallel computing architecture is presented. It has many promising characteristics such as powerful computing capability, broad I/O bandwidth, topology flexibility, and expansibility. The parallel system performance is evaluated by practical experiment.
基金Project(61170049) supported by the National Natural Science Foundation of ChinaProject(2012AA010903) supported by the National High Technology Research and Development Program of China
文摘Peta-scale high-perfomlance computing systems are increasingly built with heterogeneous CPU and GPU nodes to achieve higher power efficiency and computation throughput. While providing unprecedented capabilities to conduct computational experiments of historic significance, these systems are presently difficult to program. The users, who are domain experts rather than computer experts, prefer to use programming models closer to their domains （e.g., physics and biology） rather than MPI and OpenME This has led the development of domain-specific programming that provides domain-specific programming interfaces but abstracts away some performance-critical architecture details. Based on experience in designing large-scale computing systems, a hybrid programming framework for scientific computing on heterogeneous architectures is proposed in this work. Its design philosophy is to provide a collaborative mechanism for domain experts and computer experts so that both domain-specific knowledge and performance-critical architecture details can be adequately exploited. Two real-world scientific applications have been evaluated on TH-IA, a peta-scale CPU-GPU heterogeneous system that is currently the 5th fastest supercomputer in the world. The experimental results show that the proposed framework is well suited for developing large-scale scientific computing applications on peta-scale heterogeneous CPU/GPU systems.
文摘A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.
基金Projects(51925808,52078504,51822803) supported by the National Natural Science Foundation of ChinaProject(2022JJ10082) supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(N2022Z004) supported by the Research on Technology Development Trend and Key Common Problems in Railway,ChinaProject(Xplorer Prize 2021) supported by the Tencent Foundation,China。
文摘Installing the splitter plates is a passive aerodynamic solution for eliminating vortex-induced vibration (VIV). However, the influences of splitter plates on the VIV and aerostatic performances are more complicated due to aerodynamic interference between highway and railway decks. To study the effects of splitter plates, wind tunnel experiments for measuring VIV and aerostatic forces of twin decks under two opposite flow directions were conducted, while the surrounding flow and wind pressure of static twin decks with and without splitter plates are numerically simulated. The results showed that the incoming flow direction affects the VIV response and aerostatic coefficients. The highway deck has poor vertical and torsional VIV, and the VIV region and amplitude are different under different directions. While the railway deck only has vertical VIV when located upstream. The splitter plates can impede the process of vortex generation, shedding and impinging at the gap between twin deck, and significantly reducing the surface fluctuating pressure coefficient, thus effectively suppressing the VIV of twin decks. While, the splitter plates hurt the upstream deck regarding static wind stability and have little effect on the downstream deck. The splitter plates of appropriate width are recommended to improve VIV performances in twin parallel bridges.
文摘The grid equations in decomposed domain by parallel computation are soled, and a method of local orthogonalization to solve the large-scaled numerical computation is presented. It constructs preconditioned iteration matrix by the combination of predigesting LU decomposition and local orthogonalization, and the convergence of solution is proved. Indicated from the example, this algorithm can increase the rate of computation efficiently and it is quite stable.
文摘Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.
文摘This paper presents partially asynchronous parallel simulation of continuous-system (PAPSoCS) and some approaches to the issues of its implementation on a multicomputer system. To guarantee the simulation results correct and speedup the simulation, the scheme for efficient PAPSoCS is proposed and the virtual topology star is constructed to match the path of message passing for solving algorithm-architecture adequation problem. Under the circumstances that messages frequently passed inter-processor are much shorter, typically within several 4 bytes, asynchronous communication mode is employed to reduce the communication ratio. Experiment results show that asynchronous parallel simulation has much higher efficiency than its synchronous counterpart.
文摘In this paper, a 3rd order combination method with three processes and a 4th order combination method with five processes for solving ODEs are discussed. These methods are the Runge-Kutta method combined with a linear multistep method, which overcomes the defect of the 3rd order parallel Runge-Kutta method discussed in [1].
基金Project(2008AA01A201) supported the National High-tech Research and Development Program of ChinaProjects(60833004, 60633050) supported by the National Natural Science Foundation of China
文摘Developing parallel applications on heterogeneous processors is facing the challenges of 'memory wall',due to limited capacity of local storage,limited bandwidth and long latency for memory access. Aiming at this problem,a parallelization approach was proposed with six memory optimization schemes for CG,four schemes of them aiming at all kinds of sparse matrix-vector multiplication (SPMV) operation. Conducted on IBM QS20,the parallelization approach can reach up to 21 and 133 times speedups with size A and B,respectively,compared with single power processor element. Finally,the conclusion is drawn that the peak bandwidth of memory access on Cell BE can be obtained in SPMV,simple computation is more efficient on heterogeneous processors and loop-unrolling can hide local storage access latency while executing scalar operation on SIMD cores.
文摘Based on the efficient hybrid methods for solving initial value problems of stiff ODEs, this paper derives a parallel scheme that can be used to solve the problems on parallel computers with N processors, and discusses the iteratively B-convergence of the Newton iterative process, finally, the paper provides some numberical results which show that the parallel scheme is highly efficient as N is not too large.
文摘Gamma is a kernel programming language with an elegant chemical reaction metaphor in whichprograms are described in terms of multiset rewriting. Gamma formalism allows one to describe analgorithm without introducing artificial sequentiality and leads to the derivation of a parallel solution to agiven problem naturally. However, the difficulty of incorporating control strategies makes Gamma not onlyhard for one to define any sophisticated approaches but also impossible to reach a decent level of efficiencyin any direct implementation. Recently, a higherorder multiset programming paradigm, named higher--order Gamma, is introduced by Metayer to alleviate these problems. In this paper, we investigate the possibility of implementing higherorder Gamma on Maspar, a massively data parallel computer. The results showthat a program written in higher--order Gamma can be transformed naturally toward an efficientimplementation on a real parallel machine.
