海量DEM数据库系统研发初探

为了管理海量的数字高程模型数据,并考虑到建立大范围的虚拟场景的需要,提出一种基于组件对象模型技术、使用关系或对象关系数据库系统管理规则格网的海量地形数据的方法。通过建立具有不同比例尺和分辨率的金字塔数据库层结构以及相应的索引机制,可以管理国家标准分幅和任意矩形分幅情况下的不同分辨率的海量数字高程模型数据。最后,给出原型系统及其应用示例。     

基于ASP.NET的地理信息Web服务研究

ASP.NET是网站和XML Web服务的产物,是.NET框架中的核心要素。论文探讨了基于ASP.NET框架的地理信息Web服务(GI Web service)的实现原理,提出了服务体系软件架构,就应用服务器端组件设计、服务器端Web自定义组件设计等关键技术问题进行了深入分析,实现了一个Web服务原型系统。该原型系统经在校园网上测试,表现出良好的稳定性和较高的效率。     

基于组件式GIS的土壤质量数据库系统的开发

本文在分析土壤质量数据库的发展现状的基础上,对基于组件式GIS的土壤质量数据库系统进行了整体设计,探讨了系统的总体结构、数据组织和功能开发。本系统采用Client/Server结构以及Oracle数据库一体化数据管理和数据集成模式,并在VB编程环境下发挥MapX组件的强大功能,实现了土壤质量的可视化、空间化管理,为建立国际性的SOTER数据库提供了科学的决策基础。     

Nonlinear measurement function in the ensemble Kalman filter

ABSTRACT The optimal Kalman gain was analyzed in a rigorous statistical framework. Emphasis was placed on a comprehensive understanding and interpretation of the current algorithm, especially when the measurement function is nonlinear. It is argued that when the measurement function is nonlinear, the current ensemble Kalman Filter algorithm seems to contain implicit assumptions： the forecast of the measurement function is unbiased or the nonlinear measurement function is linearized. While the forecast of the model state is assumed to be unbiased, the two assumptions are actually equivalent. On the above basis, we present two modified Kalman gain algorithms. Compared to the current Kalman gain algorithm, the modified ones remove the above assumptions, thereby leading to smaller estimated errors. This outcome was confirmed experimentally, in which we used the simple Lorenz 3-component model as the test-bed. It was found that in such a simple nonlinear dynamical system, the modified Kalman gain can perform better than the current one. However, the application of the modified schemes to realistic models involving nonlinear measurement functions needs to be further investigated.     

An assessment of global ocean wave energy resources over the last 45 a

Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a climate change and an energy shortage.A global ocean wave energy resource was reanalyzed by using ERA-40 wave reanalysis data 1957–2002 from European Centre for Medium-Range Weather Forecasts(ECMWF).An effective significant wave height is defined in the development of wave energy resources(short as effective SWH),and the total potential of wave energy is exploratively calculated.Synthetically considering a wave energy density,a wave energy level probability,the frequency of the effective SWH,the stability and long-term trend of wave energy density,a swell index and a wave energy storage,global ocean wave energy resources were reanalyzed and regionalized,providing reference to the development of wave energy resources such as wave power plant location,seawater desalination,heating,pumping.     

2014年普通高等学校招生全国统一考试 文科综合能力测试（课标乙 地理）

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基于ArcGIS Engine的开发原理和方法的探讨

COM技术与GIS相结合产生的组件式GIS是当今GIS软件开发的主流。ArcGISEngine是ArcGIS9新推出的嵌入式组件库。在分析了组件式GIS的关键技术及ArcEngine的体系结构的基础上,使用可视化编程语言VisualBasic,结合GIS系统中一些基本功能的开发实例,探讨了利用ArcGISEngine进行二次开发的方法。     

基于浏览器的气象再分析平台通用架构及组件设计

气象再分析在互联网中的应用还处于起步阶段,缺乏成熟的系统体系及开发标准。为降低开发人员开发气象再分析产品的难度,提升开发效率,同时避免开发人员误解气象用户需求,论文总结国家科技基础条件平台运行服务主系统功能完善项目的开发过程,基于经典的MVC三层模模型,提出面向气象领域的在线再分析平台通用架构,并将架构中数据过滤和数据显示封装为组件。工作以专业气象用户需求设计效果及习惯,以开发人员的开发模式开放配置接口,建立在线平台的开发基础。该成果用于洪水监测预警系统项目的需求分析,开发人员使用通用架构,再通过三步操作:匹配数据源、设计页面布局、配置组件,完成原型开发。以此优化系统架构过程,复用已有组件。     

Forest carbon storage and tree carbon pool dynamics under natural forest protection program in northeastern China

The Natural Forest Protection(NFP) program is one of the Six Key Forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National Forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.     

MapGIS 在地质制图中的应用研究

简要讨论了MapGIS的主要功能,阐述了利用MapGIS软件制作地质图设计与制作成图的过程,以及不同专题图专题内容的表示方法。 MapGIS制图技术简化了纷繁复杂的传统地质制图过程,而且美观精确;空间分析技术可以将矢量数据和栅格数据综合制作出各种图形和图像文件,方便分析。介绍了地质图制作的工作流程、图像处理方法,以及图像生成之后地质图的校正美化。