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1.
如今大规模地理数据正在社会各个部门和组织中迅速积累,但是由于部门利益和历史沿袭等原因,大规模地理数据共享仍然极具挑战,相应共享技术需求仍然极其旺盛。作为地理数据共享的基础方式之一,传统单机地理数据格式转换技术,一方面受限于磁盘读写及带宽瓶颈,另一方面面对日趋庞大的数据规模,已很难满足实际应用需求。因此提出一种针对栅格地理数据的并行格式转换引擎,采用高性能计算集群环境支持大规模栅格地理数据转换共享,大幅降低了大规模栅格地理数据转换过程的时间成本。栅格地理数据并行格式转换引擎采用基于公共接口的设计理念,框架灵活、具有良好的扩展性,支持地理数据格式的读写自定义以及新数据格式添加,能够实现接入数据格式间的任意两两转换。为验证引擎框架及其处理效率,在Lustre并行集群环境下以格网数据交换格式(国家地理空间数据交换格式)向常见栅格地理格式的转换为示例进行了测试实验。结果表明,栅格地理数据并行格式转换引擎能够在8个节点Lustre集群中达到7.54的良好并行加速比。  相似文献   

2.
为了提高跨媒体检索的效率,可行的方法是降低数据集中不相关内容的比例。采用局部敏感哈希算法将图像数据映射到汉明空间并利用神经网络学习将文本数据映射到汉明空间的哈希函数,提出一种可以显著提高数据集中相关文件比例的高效跨媒体检索方法。实验结果表明,提出的方法能够有效去除数据集中的不相关内容,相对于已有的跨媒体检索方法,其有效提高了检索效率与准确率。  相似文献   

3.
为了满足JPEG2000遥感图像实时压缩设备的实时性要求,提出了一种基于并行机制的"零时间"数据搬移策略.通过对EBC算法结构进行拆分,并采用EDMA方式进行数据搬移,使得算法运算与数据搬移过程完全并行,搬移时间等效为零.实验结果表明,采用新的数据搬移策略后,编码效率可以提升到100%.EBc算法实现的总时间可缩短46%以上.该搬移机制已成功应用于JPEG2000星载遥感图像实时压缩系统中,系统的实时性达到了设计要求.  相似文献   

4.
为了满足JPEG2000遥感图像实时压缩设备的实时性要求,提出了一种基于并行机制的“零时间”数据搬移策略。通过对EBC算法结构进行拆分,并采用EDMA方式进行数据搬移,使得算法运算与数据搬移过程完全并行,搬移时间等效为零。实验结果表明,采用新的数据搬移策略后,编码效率可以提升到100%,EBC算法实现的总时间可缩短46%以上。该搬移机制已成功应用于JPEG2000星载遥感图像实时压缩系统中,系统的实时性达到了设计要求。  相似文献   

5.
围绕遥感数据共享分发与可视化问题,提出了一种基于模式映射的平坦关系优化分区查询框架。在该框架中,垂直分区方案基于访问特征优化节点内各属性,而水平分区方案基于统计方法优化查询的负载均衡,从而提高框架的查询性能。实验分析表明:对于同数量级的典型数据查询操作,面向查询内并行的分布式关系分区优化框架比传统集中式关系型数据库管理系统性能更优。  相似文献   

6.
分布式并行地形分析中数据划分机制研究   总被引:1,自引:0,他引:1       下载免费PDF全文
数据粒度是海量空间数据并行计算的重要问题之一。通过对不同性质的并行算法的对比分析,提出空间数据粒度模型,量化地反映并行地形分析中数据划分的规模,建立并行数据粒度评价模型。通过研究集群环境下不同算法的数据并行数据粒度问题,提出基于并行数据粒度评价模型的优化数据粒度调度算法。通过计算每一次并行计算的时间与数据粒度效率,从而实现对计算数据粒度动态更新以追求更高的加速比。经过实验验证,该算法较之传统算法,可提供更高的任务执行效率并具有更好的可移植性。  相似文献   

7.
智能训练是利用机器学习算法对神经网络智能体模型进行训练优化的过程,智能体模型通过不断试错的训练方式实现智能提升。大规模训练数据是智能训练的必要条件,通常难以从现实世界中直接获取,如何通过仿真的方式生成大量有效的训练数据,是智能训练的重要研究方向。对此提出一种基于仿真实验的智能并行训练方法,利用仿真实验管理可快速生成批量仿真实验想定,并支持节点自动部署和运行,通过合理的训练架构设计和有效训练流程设计实现智能并行训练。通过实际案例展示了智能训练的仿真实验管理过程,并结合训练效果证明了给出的方法提高了智能训练效率和智能体泛化性。  相似文献   

8.
一种测量图像相似性的新方法   总被引:5,自引:0,他引:5       下载免费PDF全文
在基于内容的图像检索技术中 ,图像相似性度量是至关重要的一步。基于EMD(EarthMover’sDistance)提出了一种度量图像相似性的方法 ,并针对图像的颜色句柄进行理论分析和实验仿真。实验结果表明了该算法的有效性  相似文献   

9.
我国通过对"嫦娥一号"卫星探测数据的处理、分析与研究,目前取得了阶段性成果,填补了我国在月球探测领域的空白,其中,根据"嫦娥一号"卫星数据制作的"全月球影像图"达到国际先进水平。  相似文献   

10.
简要回顾了人类重要探月计划的有关情况,介绍了月球影像图处理的现状和课题组研制首幅全月球三维立体图的情况。将首幅全月球立体图的制图方法与传统方法进行了技术对比分析,指出自动制图是月球遥感数据处理的新方向。  相似文献   

11.
Energy continues to serve as the bedrock of modern economies and the main driver of modern society. For Africa, the production and supply of energy resources such as crude oil, natural gas, uranium, coal, biomass, biofuels and other renewables are an important source of employment, rents, taxes, royalties and profits. This sector brings in several tens of billions of dollars of revenue annually. The production and delivery of such resources, however, depend on critical infrastructures such as pipelines, refineries, processing plants, terminals, rigs, electrical energy pylons, substations, pump stations, vessels, and tankers. These infrastructures have been attacked by terrorists, insurgents, vandals and saboteurs, all of whom see them as targets against which to register their grievances and extract concessions from the state. This paper is a chronological account of some of the documented incidents of terrorism, insurgency, kidnapping, destruction, sabotage, and human casualties suffered in the oil and gas sectors in Africa between 1999 and 2012. It is based on data extracted from the databases of the RAND Database of World Terrorism Incidents and the University of Maryland's Global Terrorism Database (GTD).  相似文献   

12.
In the Post-Bipolar Era the growing complexity of the military operations requires a new approach for the resolution of international crises. Since the end of the Cold War, peace support operations (PSO) have become the mainstay and principal occupation of most Western armies. At the same time, Italy has been one of the most important actors in such an area. The article focuses on the cooperation between military and civil components (a process called CIMIC) as a key variable in the Italian PSOs. We will analyse in detail the main lessons learned from past military interventions as well as the general context in which new tendencies are taking place. The maintaining of a minimum security frame becomes essential to fulfil activities ‘collateral’ to the mission: reconstructing services and infrastructure, food distribution, water and medication, law and order, de-mining, training of local forces, and supporting local institutions. These are the main tasks to obtain thrust and support from the population.  相似文献   

13.
This article demonstrates the inconsistent and wavering Soviet attitude towards national liberation movements in general and the Palestinian organizations in particular. Until the late 1960s, the Soviets viewed these organizations with suspicion, hesitating to engage in political dialogue with them. However, in the 1970s, political and military events in the region, as well as modifications in the Kremlin's Cold War strategies, led to a general shift towards the Middle East in Soviet foreign policy. Soviet leaders showed increased willingness to provide certain Palestinian organizations with arms with which to conduct terrorist activities against Israeli, pro-Israeli, Jewish and Western targets. The article explores the complex relations between Palestinian organizations and the USSR in the field of international terror. The study also exposes and analyzes the nature and content of Soviet–Palestinian arms dialogues and transactions. It provides clear evidence that Soviet policymakers and other luminaries were fully informed of, and sometimes directly involved in, these transactions and dialogues at the highest levels.  相似文献   

14.
The September 11 global crisis prompted by the attacks on the World Trade Center and the Pentagon raises major questions concerning the nature and trajectory of terrorism in the post-Cold War global order. Hitherto, terrorism has been largely debated by analysts at the level of nation states. Terrorist and insurgent movements have also been largely anchored in nationalist and ethnic power bases even when they have sought to mobilise a transnational ideological appeal on religious or class grounds. There have been a few exceptions to this pattern such as the alliance between the German Baader-Meinhof group and the Japanese Red Army Faction, but even such international alliances as this did not, until at least the 1980s, presage anything like a global terrorist network necessitating a global strategic response. This study examines terrorism and global strategic responses.  相似文献   

15.
This article analyses to what extent the Burmese KNU insurgency made use of external support from states, refugees, and diasporas. Based on extensive fieldwork it is concluded that support from neighbouring states and refugees has for years kept the Karen rebellion alive. Western countries perceived forms of resistance to the illegitimate Burmese regime as just and have therefore played a crucial role in the continuation of conflict in Karen State. It is important that policymakers and donors as well as executing organizations continue to reflect critically on the way they exercise their work.  相似文献   

16.
装备的RMS是装备的重要设计参数,是影响战备完好和保障能力的关键因素.引入GTST-DMLD作为主要建模工具,建立起装备系统的RMS描述模型,以ESD为补充和扩展,对维修过程进行建模.并以GTST-DMLD-ESD模型作为装备RMS仿真的核心,对装备RMS仿真模型的总体框架进行了研究,并对各模块进行了较为详细的探讨.  相似文献   

17.
18.
The UK’s interrogation operations during the conflict in Iraq (2003–2008) are often portrayed by the media as involving significant amounts of mistreatment. This article demonstrates that these practices are not necessarily representative of the UK’s interrogation operations across this conflict. In doing so it contributes to the limited literature on the practice of interrogation and on the UK’s combat operations in Iraq. The UK’s interrogation capability, and therefore its intelligence-gathering capability, is shown to have rested primarily with the military’s Joint Forward Interrogation Team (JFIT). The JFIT suffered from limitations to the number, training and experience of its interrogators and interpreters. It is argued that maintaining a permanent, higher level of preparedness for interrogation by the British armed forces is desirable.  相似文献   

19.
ABSTRACT

While the study of organised violence is considered essential to understanding the history of the West, and accordingly imbued with various layers of meaning and remembrance, war is widely regarded as inimical to the modern nation in Africa and stable development more broadly. Using examples drawn from primarily from East Africa, this paper considers the ways in which warfare in the deeper (‘precolonial’) past has been framed and envisioned in recent decades, in particular by governments whose own roots lie in revolutionary armed struggle and who began life as guerrilla movements. While in some cases particular elements of the deeper past were indeed mobilised in pursuit of contemporary political goals, in many other scenarios histories of precolonial violence were beheld as problematic and unworthy of remembrance. This paper highlights the paradox and ambiguity which has attended the memory of key aspects of Africa’s deeper past.  相似文献   

20.
ABSTRACT

What was the scope of the Bosnian jihadi participation in the war in Syria? Did the Bosnian volunteers tend to join one particular faction? Why did the Bosnian youngsters decide to join the holy war in the Levant? Was this an organized and hierarchical process or was this a grassroots movement? Last, were all the Salafis in Bosnia supportive of this dynamic or did this process cause internal frictions? These are some of the questions that this research will try to answer.  相似文献   

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