气候模式模拟中海量数据的并行抽取与可视化分析诊断     

邓春林  张怀  谭清海  王蕊  郭晓虎 《地震》2013,33(4):214-224

在地球动力学和气候模拟等领域, 数值模拟产生的数据规模达到Tb至Pb量级。 实现这些海量数据的实时可视化和实时诊断分析面临很大的困难, 时空多尺度数据抽取可以解决这一瓶颈。 高精度数据的可视化结果展示需要高分辨率的显示设备, 并行的大屏幕显示技术是解决这一问题的有效手段。 地球科学数值模拟、 并行数据抽取和高分辨率显示都需要搭建高性能计算机集群。 本文在基于Lagrange插值的多维度、 多尺度、 多分辨率并行数据抽取算法的同时, 利用并行计算节点及LCD显示器, 基于Rocks cluster系统搭建起一个176核, 4×10×1024×1280分辨率的高性能计算模拟、 数据抽取和并行显示输出的集成平台, 并将该平台成功应用到气候模式模拟产生的海量数据的并行抽取和并行显示。  相似文献   

The varve-related ice-dammed lake events in Glen Roy and vicinity: a new interpretation     

《Proceedings of the Geologists' Association. Geologists' Association》2017,128(1):146-150

This paper presents a new interpretation of the sequence of events in Glen Roy and vicinity during the Loch Lomond Stadial that can be inferred from a detailed varve record constructed by Palmer et al. (2010). 300 years of Younger Dryas glacier advance in the Scottish Highlands are recorded by very thin varves formed in an ice-dammed lake up to 35 km long. At a varve site now occupied by Loch Laggan the lake stood permanently at 260 m, but in Glen Roy varves were also laid down in a lake at 325 m and, later, 350 m caused by glacier advance. Initial ice retreat recorded by a gradual increase in varve thickness was soon followed by much thicker varves. The varve sequences are interrupted by a sand bed caused by sudden drainage of the 350 m lake. The major varves of the Glen Roy sequence show that storminess was still increasing in intensity at least 160 years after glacier retreat had begun. At the Loch Laggan site 15 cm of deformed sediments register an earthquake that produced 3 m faulted uplift of all three Glen Roy shorelines, a response to the abrupt removal of 5 km³ of water when the 260 m lake was catastrophically drained by jökulhlaup. The deformed sediments are immediately followed by varves deposited in a local lake, ice-dammed lake sedimentation now having ceased, having lasted more than 460 years.  相似文献   

GPU加速的改进PAM聚类算法研究与应用     

周恩波  毛善君  李梅  孙振明 《地球信息科学学报》2017,19(6):782-791

空间聚类是空间数据挖掘的重要方法,而K-Medoids是一种常用的空间聚类算法。K-Medoids聚类算法存在初始点选择问题,而且计算复杂。为了提高算法的有效性和时间效率,本文结合模拟退火算法思想,改进了传统的K-Medoids算法PAM,提出一种基于GPU计算的并行模拟退火PAM算法。类比矩阵乘法运算,定义了一种新的矩阵计算方法,可以有效减少数据在GPU全局内存和共享内存之间的传输,提高了算法在GPU中的执行效率。利用模拟退火算法搜索聚类中心点,保证了聚类结果的全局最优性。基于不同的数据集,将串行和并行模拟退火PAM算法以及已有的遗传PAM算法进行比较,结果表明并行模拟退火PAM算法聚类结果正确,且时间效率高。最后,应用本文改进算法对贵州省安监系统的安全监管隐患数据进行聚类分析,发现了隐患聚集中心,相关结果对政府的决策具有一定的实际应用价值。  相似文献   

并行计算技术及其在勘探地球物理学中的现状与展望   总被引：3，自引：2，他引：1       下载免费PDF全文

黄易  师学明  范建柯  胡文宝 《地球物理学进展》2010,25(2):642-649

本文详细阐述了并行计算技术及其在地球物理勘探数据处理中的发展现状和发展趋势,分析了几个代表性的并行算法实例.这些结果表明,在拥有强大的并行机的基础上,基于并行计算开发环境(MPI和PVM等)设计高效的并行算法,通过分配合理的并行粒度、通信开销、负载平衡等执行高效的并行计算,可以有效加快处理速度、降低成本.目前,并行算法在地震数据处理中应用已较为成熟,近年来向更实用的基于PC机群的并行技术发展.然而,在非地震方法中,并行算法应用较少见文献报道,研究尚处于初级研究阶段.在大地电磁的二维和三维正、反演问题上,并行计算技术逐渐得到越来越多关注和重视.随着资源和能源需求的增长,地球物理勘探向深度和广度快速发展,大幅增长的数据量使得高性能并行计算机和高效的并行算法在勘探地球物理学中的发展和应用将占据愈来愈重要的地位.  相似文献   

三江并流区云南贡山片植被景观类型分布特征   总被引：1，自引：0，他引：1  

欧光龙  彭明春  王崇云  向伶 《山地学报》2013,31(4):464-472

以三江并流区云南贡山片为例,以Landsat ETM+影像为数据源,基于3S技术进行植被景观制图,分析景观类型的分布特征。结果表明:1.研究区是典型的高山峡谷地区,海拔3 000~4 000 m的区域占总面积近一半,坡度25°以上的山地面积占84.82%;景观类型分布受垂直空间分异主导;河流、河漫滩和湖泊等景观主要分布在平缓地段,自然植被景观多分布在25°~45°的陡坡上,人工植被景观分布的坡度范围相对较缓;自然植被景观在各坡向上的分布较为均匀;人工植被景观及积雪/冰川景观、岩石景观等分布则体现出一定的空间分异;2.山地森林植被构成研究区景观的基质类型;由于植被景观的垂直分异,构成基底的各类景观类型的优势度随海拔变化,河谷地段的中山湿性常绿阔叶林、中山-亚高山的铁杉-常绿阔叶混交林、亚高山-高山的云冷杉/落叶松林优势度较高,高山-亚高山以杜鹃灌丛为优势景观类型;3.从斑块粒度上看,小斑块数量最多,占总斑块数的80.87%,中斑块占11.36%,其余均在3%以下;优势自然景观类型具有较大的巨斑块数;巨斑块面积比例最大,达到68.99%,其余斑块大小等级的分布面积比例在3%~9%之间。  相似文献   

A parallel evolutionary strategy based simulation–optimization approach for solving groundwater source identification problems     

Baha Y. Mirghani  Kumar G. Mahinthakumar  Michael E. Tryby  Ranji S. Ranjithan  Emily M. Zechman 《Advances in water resources》2009

Groundwater characterization involves the resolution of unknown system characteristics from observation data, and is often classified as an inverse problem. Inverse problems are difficult to solve due to natural ill-posedness and computational intractability. Here we adopt the use of a simulation–optimization approach that couples a numerical pollutant-transport simulation model with evolutionary search algorithms for solution of the inverse problem. In this approach, the numerical transport model is solved iteratively during the evolutionary search. This process can be computationally intensive since several hundreds to thousands of forward model evaluations are typically required for solution. Given the potential computational intractability of such a simulation–optimization approach, parallel computation is employed to ease and enable the solution of such problems. In this paper, several variations of a groundwater source identification problem is examined in terms of solution quality and computational performance. The computational experiments were performed on the TeraGrid cluster available at the National Center for Supercomputing Applications. The results demonstrate the performance of the parallel simulation–optimization approach in terms of solution quality and computational performance.  相似文献   

A parallel mesh-free contaminant transport model based on the Analytic Element and Streamline Methods     

Karl W. Bandilla  Alan J. RabideauIgor Janković 《Advances in water resources》2009

This paper introduces a new method for simulating large-scale subsurface contaminant transport that combines an Analytic Element Method (AEM) groundwater flow solution with a split-operator Streamline Method for modeling reactive transport. The key feature of the method is the manner in which the vertically integrated AEM flow solution is used to construct three-dimensional particle tracks that define the geometry of the Streamline Method. The inherently parallel nature of the algorithm supports the development of reactive transport models for spatial domains much larger than current grid-based methods. The applicability of the new approach is verified for cases with negligible transverse dispersion through comparisons to analytic solutions and existing numerical solutions, and parallel performance is demonstrated through a realistic test problem based on the regional-scale transport of agricultural contaminants from spatially distributed sources.  相似文献   

gLucifer: next generation visualization framework for high-performance computational geodynamics     

Dave R. Stegman  Louis Moresi  Robert Turnbull  Julian Giordani  Patrick Sunter  Alan Lo  Steve Quenette 《Visual Geosciences》2008,13(1):71-84

High-performance computing provides unprecedented capabilities to produce higher resolution 4-D models in a fraction of time. Thus, the need exists for a new generation of visualization systems able to maintain parity with the enormous volume of data generated. In attempting to write this much data to disk, each computational step introduces a significant performance bottleneck, yet most existing visualization software packages inherently rely on reading data in from a dump file. Available packages make this assumption of postprocessing at quite a fundamental level and are not very well suited for plotting very large numbers of specialized particles. This necessitates the creation of a new visualization system that meets the needs of large-scale geodynamic modeling. We have developed such a system, gLucifer, using a software framework approach that allows efficient reuse of our efforts in other areas of research. gLucifer is capable of producing movies of a 4-D data set “on the fly” (simultaneously with running the parallel scientific application) without creating a performance bottleneck. By eliminating most of the human efforts involved in visualizing results through postprocessing, gLucifer reconnects the scientist to the numerical experiment as it unfolds. Data sets that were previously very difficult to even manage may be efficiently explored and interrogated without writing to disk, and because this approach is based entirely on memory distributed across as many processors as are being utilized by the scientific application, the visualization solution is scalable into terabytes of data being rendered in real time.  相似文献   

Interactive visualization of 3D mantle convection     

Megan Damon  Masanori C. Kameyama  Michael Knox  David H. Porter  Dave Yuen  Erik O. D. Sevre 《Visual Geosciences》2008,13(1):49-57

The current availability of thousands of processors at many high performance computing centers has made it feasible to carry out, in near real time, interactive visualization of 3D mantle convection temperature fields, using grid configurations having 10–100 million unknowns. We will describe the technical details involved in carrying out this endeavor, using the facilities available at the Laboratory of Computational Science and Engineering (LCSE) at the University of Minnesota. These technical details involve the modification of a parallel mantle convection program, ACuTEMan; the usage of client–server socket based programs to transfer upwards of a terabyte of time series scientific model data using a local network; a rendering system containing multiple nodes; a high resolution PowerWall display, and the interactive visualization software, DSCVR. We have found that working in an interactive visualizastion mode allows for fast and efficient analysis of mantle convection results. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

一次飑线过程的雨滴谱特征研究   总被引：3，自引：0，他引：3  

王俊  姚展予  侯淑梅  龚佃利 《气象学报》2016,74(3):450-464

利用4台Thies激光雨滴谱仪组成的观测网和CINRADA/SA多普勒雷达观测资料,通过单点雨滴谱和积分参数时间序列分析、以及γ谱拟合参数和Z-R关系等的统计分析,研究成熟平行层状飑线不同部位雨滴谱和积分参数的演变特征。结果表明,不同部位雨滴谱和积分参数演变特征存在明显差别,但有一致的基本特征,即在雨强增大阶段为较小的小粒子数浓度,较大的大粒子数浓度和谱宽,而雨强减弱阶段为较大的小粒子数浓度,较小的大粒子数浓度和谱宽,所以,雨强增大阶段具有较低的雨滴浓度和较大的雷达反射率因子,以及较小的γ谱斜率参数λ和形状参数μ。但有时雨强减弱阶段存在较大的大粒子数浓度和谱宽,因此,具有较大的雷达反射率因子;统计表明,γ谱三参数N0、μ、λ与雨强的关系可以用幂函数拟合, N0随雨强增大而增大,μ、λ随着雨强的增大而减小。λ-μ关系可以用二次多项式拟合,对流云Z-R关系为Z=324R1.60。不同部位雨滴谱演变特征的差异对Z-R关系等统计关系影响明显,但对λ-μ关系影响较小。平行层状飑线不同部位雨滴谱和积分参数演变特征与拖曳层状飑线对流带典型雨滴谱演变特征类似,但也存在一些明显差别,这些差异是否与平行层状飑线动力结构的不同有关,尚需进一步的研究。   相似文献