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211.
通过分析与研究建立资源管理和作业动态分配ProRMJS模型,解决了中国地震灾害仿真网格试验系统(CEDAGrid)中网格科学计算平台在初期建设中存在的一些资源管理方面的问题. 针对网格科学计算平台默认各个计算节点均能提供计算服务的问题,ProRMJS通过ldquo;计算池rdquo;这一虚拟组织为调度器分发作业提供支撑;而调度器则根据计算池中各个节点的计算能力和状态,动态分配任务,这样就保证了计算平台的稳定性. 针对默认各个计算节点均能完成任务的问题, ProRMJS通过监控各个节点所负担作业的运行进度和设定作业时间阈值来管理作业运行. 对于各个节点计算能力大小的区别, ProRMJS通过对各个节点计算性能的权值量化,实行按ldquo;需rdquo;分配作业. 对各个节点计算性能的权值量化, ProRMJS是通过综合考虑各个因素对机器计算能力大小的影响后通过加权计算的方式完成的,从而提高了整个计算平台的工作效率. 最后通过实现地震应力触发科学计算实例验证了方案的有效性,为网格技术在地震领域内的进一步应用作了有意义的探索.   相似文献   
212.
The South Asian summer monsoon(SASM) is the most important climate system in Asia.Using observational data from the HEST2006(Himalayan Exchange between the Surface and Troposphere 2006) campaign and large-scale grid data,this paper analyzed the SASM impact on local meteorological parameters including radiation,temperature,humidity,and wind in the Himalayas.The SASM experienced one active and one break period during the HEST2006 campaign.The local meteorological parameters exhibit great differences between the active period and the break period of the SASM.The radiation fluxes are greater in the break period than in the active period.The air temperature and specific humidity are lower,but soil temperature and wind speed are higher in the break period than in the active period.Further analysis indicates that the SASM greatly affects the meteorological features of the Himalayan region.  相似文献   
213.
广西人工影响天气云系模式预报效果检验   总被引:1,自引:0,他引:1  
对广西人工影响天气云系模式预报中的柱云水量、柱过冷云水量和云顶温度3种产品进行了预报效果检验,检验结果表明:这3种模式产品对百色、南宁的预报正确率在45%~65%之间,对其它地区的预报正确率则在45%以下;柱过冷云水量预报的正确率最高,平均达到53%左右,其余2种产品平均正确率在35%左右;模式预报检验结果没有出现明显的季节差异.  相似文献   
214.
随着经济的发展,我国对高层建筑,以及智能建筑物的防雷很重视,具体的防雷措施也做的很到位.但相对于一些古建筑物来说,特别是砖木,砖石结构建筑,在防雷方面却没有引起足够的重视,现阶段能够大量保存的砖木、砖石结构建筑大部分都是具有重要历史、艺术、科学价值的革命遗址、纪念建筑物、古文化遗址、古城址、古窑址、古墓葬、古建筑、石窟寺、古民居、石刻等文物,因此对这些建筑的防雷措施应该更加重视.本文做了关于砖木、砖石结构建筑闪电分流系数研究,仅供参考,希望对砖木、砖石建筑物雷电防护工作起到一定的作用.  相似文献   
215.
With available high-resolution ocean surface wind vectors retrieved from the U.S. Naval Research Laboratorys WindSat on Coriolis, the impact of these data on genesis and forecasting of tropical storm Henri is examined using the non-hydrostatic, fifth-generation mesoscale model (MM5) of Pennsylvania State University-National Center for Atmospheric Research plus its newly released three-dimensional variational data assimilation (3DVAR) system. It is shown that the assimilation of the WindSat-retrieved ocean surface wind vectors in the 3DVAR system improves the model initialization fields by introducing a stronger vortex in the lower troposphere. As a result, the model reproduces the storm formation and track reasonably close to the observations. Compared to the experiment without the WindSat surface winds, the WindSat assimilation reduced an error between the model simulated track and observations of more than 80 km and also improved the storm intensity by nearly 2 hPa. It suggests that these data could provide early detection and prediction of tropical storms or hurricanes.  相似文献   
216.
From the volume-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6), we construct three samples with g–r color bins , labeled S1–S3, to investigate how other properties of galaxies depend on environment at fixed color. For each sample, we measure the local three-dimensional galaxy density in a comoving sphere with radius equal to the distance to the 5th nearest galaxy for each galaxy, select about 5% galaxies and construct the two subsamples at both extremes of density. Our study suggests that the environmental dependence of luminosity is mainly due to the environmental dependence of galaxy color and the correlation between color and luminosity. In addition, we preferentially conclude that concentration index and morphologies are not strongly correlated with local density at fixed color, and that galaxy color is a galaxy property very predictive of the local environment. Because SDSS spectroscopy is incomplete for bright galaxies at very low redshifts, we also use a volume-limited Main galaxy sample with a lower redshift limit z = 0.05, which contains 94,954 galaxies at 0.05 < z < 0.089 with −22.40 < Mr < −20.16, and reach the same conclusions.Due to the bimodality of the u–r color distribution, we classify galaxies as ‘red’ and ‘blue’, respectively, and further subdivide the samples into star-forming galaxies and passive ones using Hα equivalent width, W0(Hα). Results show that color and star formation activity of galaxies are galaxy properties very predictive of the local environment.  相似文献   
217.
218.
Geocell reinforcement has been increasingly applied to embankment engineerings. Deformation calculation is one of the major concerns during the design process. Using Winkler foundation model and with consideration of the interface resistance effect, a deformation control differential equation for the geocell reinforced mattress under the vertical symmetric loads is presented in this paper. The corresponding power-series semi analytic solutions for the displacements and the internal forces of geocell reinforcement are also presented. Furthermore, the influence factors such as loads, length and flexural rigidity of geocell reinforcement, coefficient of subgrade reaction and the interface resistance on the stress-deformation characteristic of geocell reinforcement are discussed. Finally, two examples are employed to verify the presented method. This study suggests that the effect of the interface resistance on the deformation of geocell reinforcement should be considered in engineering design.  相似文献   
219.
220.
A commonly used measure to prevent soil wind erosion is to cover the surface with gravel. Gravel can inhibit soil erosion by covering the surface directly, changing the airflow field near the surface and sharing the shear stress of wind. Similar to other roughness elements, the protective effect of gravel on soil is usually expressed in terms of the ratio of the shear stress on the exposed soil surface to the total shear stress on the rough surface due to wind, i.e. through a shear-stress partitioning model. However, the existing shear-stress partitioning models, represented by Raupach's model (RM93), are only applicable when the lateral coverage of the roughness elements, λ < 0.10, and the applicability of the models to flat-shaped roughness elements is unclear. The purpose of this study is to verify the applicability of RM93 for dense and flat-shaped gravel roughness elements by using shear-stress data from wind-tunnel measurements pertaining to roughness elements with different densities (0.013 ≤ λ ≤ 0.318) and flat shapes (height-to-width ratios in the range 0.20 ≤ H/W ≤ 0.63), and to modify RM93 to enhance its predictive ability. The results indicate that RM93 cannot accurately predict the shear-stress partitioning for surfaces covered by densely distributed and flat-shaped gravel roughness elements. This phenomenon occurs because, when roughness elements are distributed densely or are flat-shaped, the proportion of the shear stress on the top surface of the roughness elements (τc) to the total shear stress (τ) is large; in this case, τc plays a dominant role and serves as an essential component in the shear-stress partitioning model. Consequently, RM93 is modified by incorporating τc into the calculation of τ. Under conditions of λ < 0.32 and H/W > 0.2, the modified RM93 can yield satisfactory predictions regarding the shear-stress partitioning.  相似文献   
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