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161.
随着空间大数据技术的快速发展,越来越多与空间大数据云平台相关的项目逐步规划和建立.GIS建设项目已经朝着平台化、虚拟化和智能化的方向转变.新一代GIS平台建设的重要原则之一,就是要把空间大数据作为企业的重要资产.它需要系统地管理、持续地维护、安全地控制以及深入地挖掘.在持续探索数据价值的过程中,对平台基础设施提出了新的技术要求,包括集成多种开源技术、支持快速的迭代开发、支持持续运行的数据分析任务等.本文研究的重点是结合DevOps等先进的面向持续交付的管理理念,利用相关技术提出空间大数据基础设施的设计方案,使其具备持续交付能力. 相似文献
162.
Deep Penetration of Spudcan Foundation into Double Layered Soils 总被引:5,自引:1,他引:5
The spudcan foundation has been widely used in offshore engineering for jack-up figs. However, “punch through”failure often occurs where a stronger soil layer overlays a softer soil layer. In this study, spudcan penetration into double layered soils is investigated numerically. The soil profde is set up as a stronger soil layer overlaying a softer soil layer,with the soil strength ratio ( bottom soil strength / top soil strength) varied from 0.1 to 1.0 ( 1 means uniform soil). The bearing bohaviour is discussed and the beating capacity factors are given for various cases involving different layer thicknesses and different strength ratios of the two clay layers. The development of the plastic zones and the effect of soil selfweight on the beating capacity are also discussed. From this study, it is found that, when a spudcan is distant from the soil layer boundary, the spudean can be analysed with single soil layer data. However, when a spudcan becomes closer to the soil boundary layer, the influence of the lower soft soil layer is significant, and the beating capacity of the spudean decreases. The critical distance is an indication of the occurrence of “punch through” failure. The critical distance between the spudcan and the layer boundary is larger for a rough spudean than the one for a smooth one, and the critical distance decreases with increasing soil strength ratio. The depth of cavity formed during initial spudcan penetration depends on the top layer soil strength, soil strength ratio and unit soil self-weight, and the cavity affects the spudcan beating behaviour as well. 相似文献
163.
164.
Analysis of influencing factors on fine sediment flocculation in the Changjiang Estuary 总被引:1,自引:0,他引:1
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes. 相似文献
165.
Keisuke?Yamaguchi Ju?Lin Arata?KanekoEmail author Tokuo?Yayamoto Noriaki?Gohda Hong-Quang?Nguyen Hong?Zheng 《Journal of Oceanography》2005,61(2):283-294
Tidal current structures at the Hayatomono-Seto of the Kanmon Strait are mapped continuously during March 17 to 20, 2003, including a spring tide, by the eight coastal acoustic tomography (CAT) systems distributed on both the sides of the strait. Detailed structures of strong tidal currents and their associated vortices are well reconstructed by the inverse analysis of travel-time difference data obtained from the reciprocal sound transmission between the paired CAT systems located at both sides of the strait mainly. The results are well compared to the shipboard acoustic Doppler current profiler (ADCP) data at the correlation rate of 0.84/0.82 and the RMS difference of 0.47/0.48 ms−1 for the east-west/north-south current after the selection of good data. During the observation period, the maximum hourly mean volume transport for the upper 7 m layer across the strait reached 13,314 m3 s−1 for the eastward and 5,547 m3 s−1 for the westward. The daily mean transport is directed to the eastward and estimated 1,470 m3 s−1 and 2,140 m3 s−1 for March 18 and 19, respectively, when a spring tide occurs. 相似文献
166.
基于MCT耦合器,利用中尺度大气模型WRF、海洋模型FVCOM和第三代海浪模型SWAN,实现大气、海洋和海浪的三者实时耦合计算,同时采用卫星微波辐射资料AMSU-A,通过WRF大气模式的资料同化模块WRFDA,实现对风场模拟的连续同化,从而建立起大气-海洋-海浪耦合与卫星数据同化的W-F-S-A耦合同化模式。将该模型应用于2014年台风“威马逊”的数值模拟,并与其他模型进行比较。结果表明,W-F-S-A耦合同化模式对于台风路径和风速的模拟结果优于单独耦合和单独同化结果,并且可以较好地模拟上层海洋对台风的响应特征。 相似文献
167.
TraCE-21ka是全球首个利用全耦合模式针对末次盛冰期(LGM)至今气候演变的瞬变模拟。利用现代再分析资料和历史特征时期重建的连续冻土边界对TraCE-21ka模拟做了评估。结果表明TraCE-21ka能够较好地模拟现代半球尺度环流和降水的空间形态,对东亚地区的模拟冬季较好而夏季欠佳。TraCE-21ka模拟的现代时期与再分析资料相比偏冷,北半球年平均表面温度比再分析资料低3~4 ℃,基于现代温度误差的分析表明TraCE-21ka对东亚地区气候演变的模拟欠佳。对于历史特征时期,重建的连续冻土边界线指示TraCE-21ka模拟的亚欧大陆在LGM偏暖,全新世中期偏冷,即低估了LGM以来的变温幅度。利用连续冻土边界线的年均表面温度约为-7 ℃这一特性,进一步定量评估出TraCE-21ka模拟的亚欧大陆中纬地区从LGM至今的升温幅度约为真实气候的40%。通过分析近百年全球升温速率证实TraCE-21ka的气候敏感性显著偏低,由此产生的误差在瞬变模拟中会不断累积。 相似文献
168.
169.
1855年黄河铜瓦厢决口北流,改道从山东入海,是一次百年灾害链形成的巨变,黄淮海平原成为中国水灾的中心。经研究发现:1740—1818年为中国地震宁静期,黄河流域正处于干旱枯水期;1819年印度卡其发生8.3级大地震,黄河出现多泥沙特大洪水,河南兰阳以下近30 km河道严重淤塞;1819—1879年大地震密集出现,并有9级以上特大地震4次,其中1833—1870年大地震主要分布在东亚;黄河因而于1841—1843年连续出现特大洪水,造成下游多次决溢、以致改道。文中第一次以科学和历史结合给出解释,其结论可供当前地球科学灾害链研究及治黄参考。 相似文献
170.
There are three aspects in the study of GPS meteorology network in the Wuhan region. The first is the comparison of the GPS precipitable water vapor between final ephemeris and ultra-rapid ephemeris for which the relative coefficient is 99.97 and the root mean squares is 0.048 mm. It can be concluded that ultra-rapid ephemeris can be used to get the GPS precipitable water vapor for the real-time prediction. The second is the comparison of precipitable water vapor of GPS stations and the distribution of water vapor in the Wuhan region is acquired. The change of GPS precipitable water vapor and rainfall in a rainfall process are compared and analyzed. The change of GPS precipitable water vapor can reflect and predict the process of rainfall. 相似文献