Parallel recovery method in shared-nothing spatial database cluster system

Shared-nothing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed. However if the failed node wouldn‘t be recovered quickly, whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques, external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly. Also recovery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-nothing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed.However if the failed node wouldn't be recovered quickly, whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques, external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly.Also recovery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

基于GMS应用的化工区地下水污染模拟与分析

 GMS是目前地下水数值计算的重要应用软件之一,运用GMS可以模拟地下水流分布和地下水污染物的迁移规律等。以化工厂区为例,经过地质模型概化、参数确定、调参等过程,预测污染物的浓度及污染范围。研究了该厂区渗滤液的扩散对下游抽水井的影响,建立了该厂区地下水流模型及溶质运移模型。结果表明,该区域地下水流向为自北向南,沿水流方向水位逐渐下降,水降幅度较为缓和,在下游抽水井附近形成地下水降落漏斗;污染物的浓度在持续增加,局部污染物浓度高达4.1mg/L,污染的范围也逐渐扩大,污染面积约为8.23×10⁵ m²,污染物向下游扩散长度约1084.64 m,在垂向上,厂区位置污染物已经扩散到第二层深水含水层。若不加以控制抽水量,会加剧污染物的扩散速度。     

安徽五沟煤矿1016面底板突水GMS模拟模型研究

由于水文地质条件的复杂性和开采技术的多样性,目前底板水的运移及突水量预测仍然较为困难。根据五沟煤矿现场工程地质、水文地质条件,通过概化水文地质条件,建立数学模型。采用GMS软件,建立1016面开采涌水模拟模型,通过对模型的检验分析,验证模型的准确性,为深入系统地研究五沟煤矿1016工作面底板岩层破坏机理和突水条件以及为煤矿防治水设计提供依据。     

利用GMS卫星资料进行强对流降水估计

对利用静止卫星云图资料进行降水的估计方法进行了回顾,在总结前人方法的基础上。针对GMS云图资料及华南地区的特点对强对流云团降水方法进行了研究,包括冷云区持续时间估计法、红外亮温法,并将梯度、发展率和常规探测资料加入其中进行分析。结果显示,综合几种资料,能较好地进行强降水的估计。     

基于大井法和地下水模型系统数值模拟方法的某矿坑涌水量预测对比分析

摘 要：在矿山实际生产过程中,涌水量精确预测具有重要意义。为解决预测值准确度不够的问题,本文运用大井法和GMS数值模拟方法进行某矿坑涌水量双重预测对比分析。采用地下水动力学“大井法”的承压转无压公式：得出最大降深平均涌水量为47948m3/d,最小降深平均涌水量为46501m3/d;使用GMS数值模拟软件得出矿坑平均涌水量为32000m3/d,最大涌水量为38000m3/d。对二者结果进行对比分析：大井法预测公式是在含水层水平、等厚、均质等严格条件下推导出来的,但矿山实际上并没有完全满足公式的前提条件,其预测结果将会偏大;数值模拟方法适应性强,预测精度高,已经被大量应用于各个方面,由该方法得出的数据将会比大井法得出的数据范围小且更为精确。双重预测方法得出该矿坑涌水量的大范围和小范围预测值,结果表明该矿坑涌水量较大是不争的事实,研究成果将为开采矿山提供技术支撑。     

大湄公河次区域植被覆盖时空变化特征及其与气象因子的关系

【目的】分析大湄公河次区域植被覆盖的时空分布变化规律及其与气象因子之间的关系,为全球变暖环境下大湄公河次区域植被保护及生态环境修复提供理论依据。【方法】以大湄公河次区域为研究区,使用MOD13Q1-NDVI数据,借助Google Earth Engine(GEE)平台反演区域2005—2019年植被覆盖,采用线性回归分析、马尔科夫模型等分析区域植被覆盖的时空分布规律,并利用偏相关分析法探究植被覆盖与气象因子之间的关系。【结果】大湄公河次区域高植被覆盖的面积占总面积的61.9%,空间上呈现北低南高、东高西低的特点;2005—2016年,区域植被以改善为主,主要是中高植被向高植被类型转化;2016—2019年,区域植被发生明显退化,以高覆盖植被类型退化为主;15年来,呈改善趋势的面积占总面积12.7%,呈退化趋势的面积占总面积3.0%,基于Hurst指数分析发现,区域植被未来显著改善面积大于显著退化,南部地区未来会发生退化;年际变化趋势上,归一化植被指数(NDVI)与气温呈显著正相关,相关系数为0.61,与降水相关性较弱;空间上,区域植被NDVI变化受到气温和降水影响,北部与降水显著负相关,南部与气温显著负相关。【结论】大湄公河次区域植被覆盖整体较好,改善趋势大于退化趋势。综合来看,大湄公河次区域植被变化与气温和降水有一定关系,尤其是北部和南部。     

一种低风速测量仪的研究与实现

分析了低风速测量技术的主要功能结构及工作流程,采用GM8120 SoC芯片作为运算单元,通过经验函数对低风速进行测量。     

Parallel recovery method in shared-nothing spatial database cluster system

Shared-notliing spatial database cluster system provides high availability since a replicated node can continue service even if any node in cluster system was crashed. However if the failed node wouldn’t be recovered quickly,whole system performance will decrease since the other nodes must process the queries which the failed node may be processed. Therefore the recovery of cluster system is very important to provide the stable service. In most previous proposed techniques,external logs should be recorded in all nodes even if the failed node does not exist. So update transactions are processed slowly. Also reccvery time of the failed node increases since a single storage for all database is used to record external logs in each node. Therefore we propose a parallel recovery method for recovering the failed node quickly.     

地学三维GIS可视化系统

针对地学研究三维模型中存在的问题,在总结分析已有的多种建模方法的基础上,根据矿体的不规则性,采用ATP建模方法,具体研究并提出了三维GIS可视化系统的设计方案,利用OpenGL图形库实现地矿3D模型的可视化技术,从而方便地生成高真实感的三维图形,并对地质三维空间分析方面的功能作了进一步的研究探讨,能够为矿藏及各种地质现象描述提供科学的依据。