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1.
为应对海量遥感影像快速计算的需求,通过对影像获取、算法和计算过程优化和改进,提出了一种基于Apache Spark并行计算框架的MODIS海表温度反演方法,实现了海量MODIS遥感影像的海表温度快速反演.应用四轮网络查询请求获取特定的时空范围影像数据,提高影像获取阶段的效率;应用简化算法参数、拟合过程变量改进海表温度劈窗算法,使之适合快速并行计算;应用弹性分布式数据集(RDD)窄依赖关系的优点,避免并行计算中的数据交换延迟.通过单机模式与集群模式对比实验,发现集成了并行计算框架的集群模式影像处理效率约为单机模式的10倍.研究结果表明了融合集群计算技术的海表温度反演过程有效提高了传统单机应用程序的处理效率.  相似文献   

2.
并行计算六十年   总被引:4,自引:0,他引:4  
并行计算是实现高性能计算的主要技术手段。本文回顾了并行计算技术六十多年来的发展历史,重温了并行可扩展性度量公式在并行计算发展进程中的重要地位。分析了并行计算向未来E级计算发展时面临的挑战,并建立了新的并行计算可扩展性度量模型,建模了访存、通信、可靠性、能耗等影响E级计算的因素。通过定量分析,发现和研究了并行计算向更高性能发展面临的可扩展性"墙"。最后,针对我国国情,提出了作者关于我国高性能计算未来发展的体会与思考。  相似文献   

3.
并行计算模型对比分析   总被引:1,自引:0,他引:1  
王欢  都志辉 《计算机科学》2005,32(12):142-145
随着集群式系统的发展,并行计算模型在估计和评价系统的性能、引导集群的体系结构以及指导并行算法和程序的设计等方面都显得越来越重要。对于目前已有的并行计算模型的设计思想和原理的了解和分析,非常有利于新的模型的设计与研究。本文首先介绍了目前比较常见的5种并行计算模型,接着在同步性、通信方式和参数等3个方面分析比较了它们的异同和优缺点,最后得出结论,指出了下一代并行计算模型的发展趋势是与具体应用相关的并行计算模型。  相似文献   

4.
本次论文首先对并行计算进行了基础性的分析,主要包括软、硬件体系结构、编程模型、算法等,涉及了并行计算中的新技术,也包含了传统的算法。在比较了MPI、PVM和OpenMP作为编程模型的利弊之后,选择了MPI作为并行计算环境,最后在搭建好的并行式Matlab平台中运行了几个例子,初步展现了并行计算的高效与快捷。  相似文献   

5.
针对能源应用领域的地震资料处理对高性能并行计算的需求,介绍了一种集群系统的设计与实现方案。寸集群系统中易产生性能瓶颈的网络通信子系统、存储子系统、全局共享文件系统这些关键子系统提出了详细的设计方法与实现技术。同时对集群系统管理、地震资料处理的并行计算应用部署给出了具体的实现方法。最后分别使用LINPACK基准测试与地震资料处理并行计算应用实测结果,验证该集群系统芷高性能并行计算方面的优越性。  相似文献   

6.
网络通信性能是影响网络并行计算的重要原因,而交换式网络的出现有助于改变这状况。本文定量地分析了基于交换式以太网的网络并行计算系统中的端到端通信和多目的发送两种通信方式的通信性能,并对一个典型的并行计算实例──并行距阵乘法进行了性能评测。通过与基于共享式以太网的网络并行计算系统中测试结果的对比,我们可以看出交换式以太网对改进网络并行计算性能的重要作用。  相似文献   

7.
为了研究基于分布式对象的并行计算,采用微软Windows Communication Foundation中的对等网络技术,设计并实现了一个并行计算环境。以并行求π为例,通过比较并行计算的加速比,证明了本并行计算环境的有效性。  相似文献   

8.
为具体了解CFD软件NUMECA FINE/Turbo的并行计算性能,良好把握后续的科研工作进度,分别研究在激活超线程情况下单节点计算与多节点并行计算以及CPU在激活超线程前、后计算速度的差异.结果表明:在多节点并行计算时,计算速度与实际参加并行计算的CPU物理核心数量成正比;在激活超线程的情况下,并行计算节点数在超过实际物理核心数后明显降低计算速度的提升.  相似文献   

9.
并行计算软件库,如scalapack和plapack,通过提供大量并行计算子过程来提高并行计算软件开发效率。为方便用户使用并行软件库,该文提出了一种基于性能预测技术来开发并行计算软件库的方法,这是一种隐藏并行计算细节的有效途径。并就构成该软件库的神威超级计算机系统并行软件开发工具,并行线性代数软件库的数据自动分布的方法和供用户调用并行软件库的接口设计技术进行了讨论。实验结果表明,这种技术能有效提高并行计算软件效率。  相似文献   

10.
设计一种基于以太网的多DSP并行计算系统,以解决当今大规模通信系统中日益复杂的实时计算问题。采用ADI公司的Blackfin系列芯片作为处理器,通过主从模式实现一个完整的并行计算系统。将多处理器并行系统与单个处理器系统的处理结果进行对比分析,验证了并行计算的优越性。  相似文献   

11.
LASG/IAP全球海洋环流模式的并行计算及其优化   总被引:2,自引:0,他引:2  
研究了中国科学院大气物理研究所大气科学与地球物理实验室(LASG/AP)的全球海洋环流模式的串行计算特点,分析了共可扩展并行性,实现了基于一维纬向剖分的分布式存储和共享存储并行计算。结合目前高性能计算机的技术特点,研究了并行海洋环流模式的计算优化,提出若干优化策略。  相似文献   

12.
描述了模拟退火算法在石油勘探中求解剩余静校正量问题上的应用及其数学模型,综合冷却进度表的构造方法和对算法的改进,设计出了新的串行算法和基于操作步区域分裂策略的并行算法。最后给出了性能实验结果。ARSCSA ARSCSA  相似文献   

13.
14.
This is the first paper in a two-part series that describes a massively parallel code that performs 2D frequency-domain full-waveform inversion of wide-aperture seismic data for imaging complex structures. Full-waveform inversion methods, namely quantitative seismic imaging methods based on the resolution of the full wave equation, are computationally expensive. Therefore, designing efficient algorithms which take advantage of parallel computing facilities is critical for the appraisal of these approaches when applied to representative case studies and for further improvements. Full-waveform modelling requires the resolution of a large sparse system of linear equations which is performed with the massively parallel direct solver MUMPS for efficient multiple-shot simulations. Efficiency of the multiple-shot solution phase (forward/backward substitutions) is improved by using the BLAS3 library. The inverse problem relies on a classic local optimization approach implemented with a gradient method. The direct solver returns the multiple-shot wavefield solutions distributed over the processors according to a domain decomposition driven by the distribution of the LU factors. The domain decomposition of the wavefield solutions is used to compute in parallel the gradient of the objective function and the diagonal Hessian, this latter providing a suitable scaling of the gradient. The algorithm allows one to test different strategies for multiscale frequency inversion ranging from successive mono-frequency inversion to simultaneous multifrequency inversion. These different inversion strategies will be illustrated in the following companion paper. The parallel efficiency and the scalability of the code will also be quantified.  相似文献   

15.
In this work a possible model for organizing a grid-based application that performs the solution of several inverse geophysical problems is described. As an example, we consider the problem of determining the parameters of seismic anisotropy in the Earth’s mantle by the inversion of seismic waveforms. It is shown that this class of problems is reduced to the tabulation of a complicated multidimensional function. In this approach, the calculation at each point in a definition interval is calculated independently, so this is ideally appropriate for calculations that use a loosely connected distributed computing infrastructure.  相似文献   

16.
地震并行处理模式与应用框架   总被引:4,自引:0,他引:4  
文中研究石油地震数据处理的并行计算设计模式(流水、扇出/扇入、主从和混合)和应用框架,框架和模式的目的都是复用成功的软件设计自力更生,框架可以看作一类设计模式的具体实现。针对地震数据处理模式设计和实现了GRISYS地震数据处理应用框架。利用这个框架,以往大量的串行地震处理模块,不需要任何改动,可以在工作站集群计算机或大规模并行计算机上实现并行计算,在曙光2000-Ⅱ并行计算机上试验,获得了非常高的并行处理加速比。  相似文献   

17.
根据某大型双层柱面网壳风致静力响应计算的有限元模型,建立基于GPU的MATLAB快速并行计算平台,实现CUDA框架下多自由度结构风致静力位移响应的快速求解.数值计算表明,与传统的CPU串行计算相比,通过GPU实现的大型矩阵的求逆、乘法、除法等运算速度得到大幅提高,位移计算获得23倍的最大加速比;结果误差对比分析也表明基于GPU的计算结果能够满足工程精度要求.  相似文献   

18.
Estimating Uncertainties for Geophysical Tomography   总被引:1,自引:0,他引:1  
We present statistical and interval techniques for evaluating the uncertainties associated with geophysical tomographic inversion problems, including estimation of data errors, model errors, and total solution uncertainties. These techniques are applied to the inversion of traveltime data collected in a cross well seismic experiment. The inversion method uses the conjugate gradient technique, incorporating expert knowledge of data and model uncertainty to stabilize the solution. The technique produced smaller uncertainty than previous tomographic inversion of the data.  相似文献   

19.
A very simple radial basis function neural network (RBFNN) is investigated for hyperspectral remote sensing image classification. Its training can be analytically solved with a closed-form equation, and no parameter needs to be manually tuned. Its computational cost is much lower than the popular support vector machine (SVM). Surprisingly, such an RBFNN can achieve the performance that is similar to or even better than the SVM. By incorporating a simple spatial averaging filter or a Gaussian lowpass filter with negligible additional computational cost, classification accuracy can be further improved. Considering the large matrix inversion operation in the RBFNN when the number of training samples being very large, we also propose a parallel processing method to reduce computing time in matrix inversion.  相似文献   

20.
A control structure is considered for decoupling and linearizing the dynamic behavior of a robotic manipulator. Since computational efficiency is a crucial consideration in implementation of this control system, a fast recursive algorithm is presented for the necessary digital computations, and the computational requirements are studied in terms of the number of degrees of freedom of a general and open-chain robotic manipulator. An important feature of the algorithm is that decoupling is realized without employing matrix inversion. The sequential recursive algorithm is restructured into a parallel algorithm. A significant improvement in the computational speed is achieved in this manner. The computing requirements of the parallel algorithm are compared with those of the serial algorithm. For a six-degrees-of-freedom robot, the computational cost of the parallel algorithm is approximately 23 % of that of the original serial algorithm. Finally, the processor loads in some regions of the parallel algorithm are redistributed to achieve a balanced scheme. The resulting parallel algorithm requires approximately 17% of the computational effort of the serial algorithm, for a six-degrees-of-freedom robot.  相似文献   

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