甘肃省地震局高性能计算系统

高性能计算是现代科学研究、工程技术开发和大规模数据处理的关键支撑技术,在地震系统发挥着日益重要的作用。甘肃省地震局高性能计算集群系统由60个节点、采用40 GB InfiniBand网络互连组成,峰值计算速度达9.2万亿次/秒。作为地震系统重要的科技服务平台之一,为地震反演、数据分析、数值模拟等领域以及科研创新平台提供高性能计算环境。     

Rapid,high-resolution detection of environmental change over continental scales from satellite data – the Earth Observation Data Cube

The effort and cost required to convert satellite Earth Observation (EO) data into meaningful geophysical variables has prevented the systematic analysis of all available observations. To overcome these problems, we utilise an integrated High Performance Computing and Data environment to rapidly process, restructure and analyse the Australian Landsat data archive. In this approach, the EO data are assigned to a common grid framework that spans the full geospatial and temporal extent of the observations – the EO Data Cube. This approach is pixel-based and incorporates geometric and spectral calibration and quality assurance of each Earth surface reflectance measurement. We demonstrate the utility of the approach with rapid time-series mapping of surface water across the entire Australian continent using 27 years of continuous, 25?m resolution observations. Our preliminary analysis of the Landsat archive shows how the EO Data Cube can effectively liberate high-resolution EO data from their complex sensor-specific data structures and revolutionise our ability to measure environmental change.     

Application of a 2D harmonic polynomial cell (HPC) method to singular flows and lifting problems

Further developments and applications of the 2D harmonic polynomial cell (HPC) method proposed by Shao and Faltinsen [22] are presented. First, a local potential flow solution coupled with the HPC method and based on the domain decomposition strategy is proposed to cope with singular potential flow characteristics at sharp corners fully submerged in a fluid. The results are verified by comparing them with the analytical added mass of a double-wedge in infinite fluid. The effect of the singular potential flow is not dominant for added mass and damping, but the error is non-negligible when calculating mean wave loads using direct pressure integration. Then, the double-layer nodes technique is used to simulate a thin free shear layer shed from lifting bodies, across which the velocity potential is discontinuous. The results are verified by comparing them with analytical results for steady and unsteady lifting problems of a flat plate in infinite fluid. The latter includes the Wagner problem and the Theodorsen functions. Satisfactory agreement with other numerical results is documented for steady linear flow past a foil and beneath the free surface.     

Spatial transferability of the physically based model TRIGRS using parameter ensembles

The development of better, more reliable and more efficient susceptibility assessments for shallow landslides is becoming increasingly important. Physically based models are well-suited for this, due to their high predictive capability. However, their demands for large, high-resolution and detailed input datasets make them very time-consuming and costly methods. This study investigates if a spatially transferable model calibration can be created with the use of parameter ensembles and with this alleviate the time-consuming calibration process of these methods. To investigate this, the study compares the calibration of the model TRIGRS in two different study areas. The first study area was taken from a previous study where the dynamic physically based model TRIGRS was calibrated for the Laternser valley in Vorarlberg, Austria. The calibrated parameter ensemble and its performance from this previous study are compared with a calibrated parameter ensemble of the model TRIGRS for the Passeier valley in South Tyrol, Italy. The comparison showed very similar model performance and large similarities in the calibrated geotechnical parameter values of the best model runs in both study areas. There is a subset of calibrated geotechnical parameter values that can be used successfully in both study areas and potentially other study areas with similar lithological characteristics. For the hydraulic parameters, the study did not find a transferable parameter subset. These parameters seem to be more sensitive to different soil types. Additionally, the results of the study also showed the importance of the inclusion of detailed information on the timing of landslide initiation in the calibration of the model.     

消防射水对火灾后高性能混凝土剩余抗压强度的影响

对火灾后消防射水对高性能混凝土（HPC）剩余抗压强度的影响进行了研究。分析了在不同温度、不同冷却方式条件下,C40HPC剩余抗压强度的变化规律,并利用ORIGIN 7.5软件,拟合了高温作用后HPC剩余抗压强度与温度之间的关系。研究表明：消防射水对高温作用后的HPC的剩余抗压强度的影响很大,射水冷却后的HPC剩余抗压强度明显低于自然冷却后的剩余抗压强度;随着破坏温度的升高,经消防射水冷却的HPC剩余抗压强度呈衰减状态。最后,建立了自然冷却及消防射水冷却条件下,C40HPC剩余强度与火场温度之间的二元回归曲线公式。     

基于GPU的地震属性提取

地震属性技术可从地震资料中提取出隐藏其中的有用信息,不仅提高了原始地震资料的利用价值,同时也提高了地震技术在石油工业中的应用水平。随着三维地震勘探技术的广泛应用,解决了二维勘探中存在的一些问题,但同时也带来地震数据量的激增。地震勘探技术的不断发展,对高性能计算提出了更高的要求,新的高性能计算技术不断被应用到地震勘探中。近年来,因GPU的计算性能迅猛发展,使之成为高性能计算的一个重要发展方向。这里基于CUDA（计算统一设备架构）编程平台,利用GPU加速地震属性提取。通过对比发现,利用GPU可以得到六倍左右的加速比,这表明应用GPU可以有效地缩短程序的运行时。     

低周反复荷载下高性能混凝土震损框架的抗震性能

基于预应力与非预应力高性能混凝土震损框架的低周反复荷载试验，对其受力过程、破坏形态、滞回曲线、骨架曲线、恢复力模型、变形恢复能力、刚度退化、耗能能力等抗震性能进行较为深入的研究与分析。研究表明：高性能混凝土震损框架的抗震性能较震损前有明显的降低，但仍具有一定的抗震能力。     

The Lofar Central Processing Facility Architecture

Reconfiguration is a key feature characteristic of the LOFAR telescope. Software platforms are utilised to program out the required data transformations in the generation of scientific end-products. Reconfigurable resources nowadays often replace the hard-wired processing systems from the past. This paper describes how this paradigm is implemented in a purely general-purpose telescope back-end. Experiences from high performance computing, stream processing and software engineering have been combined, leading to a state-of-the-art processing platform. The processing platform offers a total processing power of 35 TFlops, which is used to process a sustained input data- stream of 320 Gbps. The architecture of this platform is optimised for streaming data processing and offers appropriate processing resources for each step in the data processing chains. Typical data processing chains include Fourier transformations and correlation tasks along with controlling tasks such as fringe rotation correction. These tasks are defined in a high level programming language and mapped onto the available resources at run time. A scheduling system is used to control a collection of concurrently executing observations, providing each associated application with the appropriate resources to meet its timing constraint and give the integrated system the correct on-line and off-line look and feel.     

聚丙烯纤维高性能混凝土剪力墙动力反应分析

对掺聚丙烯纤维的高性能混凝土剪力墙的动力反应特性进行了研究。首先通过试验测得聚丙烯高性能混凝土的一些力学参数，而后编写了结构动力反应计算程序，最后利用该程序对一15层剪力墙实例进行计算，比较了普通混凝土与高性能混凝土剪力墙结构的动力反应结果，结果表明聚丙烯高性能混凝土剪力墙比普通混凝土剪力墙具有更好的抗震性能。     

网格高性能PGIS的研究与开发

介绍参与式地理信息系统(PGIS)技术概念,简要分析PGIS在(C/S)网络结构下的一些核心问题。提出应用高性能计算与网格技术改进现有PGIS的思想,并以一个不同地点、同时间的地理协作案例,设计实现了一种基于网格的高性能PGIS以引导实施交通紧急疏散系统。