基于网格技术的空间知识发现与数据挖掘研究   总被引：3，自引：0，他引：3  

葛小三 《武汉大学学报(信息科学版)》2006,31(12):1105-1107

设计了基于服务网格的空间知识发现与数据挖掘的槊构，并对其关键技术进行了探讨性研究。  相似文献   

线性体图像自动矢量化算法研究     

李增兵  张晓帆 《测绘与空间地理信息》2006,29(5):22-24

依据线图的结构特点,首先提取节点信息快速抓住图像的总体拓扑结构,然后以节点信息指导进行矢量跟踪,能够有效解决复杂的交叉点问题,提高矢量化的效率和精度。基于节点信息指导和对不同连通体分类跟踪的方法避免了跟踪起始点选取的随意性和跟踪方向选取的盲目性,并具有抗噪性好和适应性强的特点。  相似文献   

基于图模犁和拓扑约束的管网数据一致性检测     

韦人玮吴小芳  杜清运 《地理空间信息》2006,4(1):52-54

正确可靠的数据是GIS系统的核心。针对管网数据的复杂性，提出利用圈数据模型描述管网拓扑关系．并使用拓扑约束方法对管网数据一致性进行检测，以确保数据的正确性。该方法吸收了基于连接规则以及基于拓扑关系约束的方法的优点，能够更好的描述管网系统的整体结构并对其进行拓扑约束，使得一致性检测更加全面。  相似文献   

基于图斑空间关系的遥感专家分类方法研究   总被引：3，自引：0，他引：3  

蔡晓斌  陈晓玲  王涛  吴忠宜 《武汉大学学报(信息科学版)》2006,31(4):321-324

以光谱均质单元——图斑作为空间对象粒度的基本单元，采用图斑邻域搜索算法，获取不同类别图斑间的空间关系。在ERDAS专家分类系统中，根据图斑相邻关系以及DEM信息对初始分类结果进行了修正，提高了湿地、草地和农业用地的分类精度。  相似文献   

未来的天气气候预测体系   总被引：12，自引：3，他引：12  

叶笃正  严中伟  戴新刚  钱维宏  叶谦 《气象》2006,32(4):3-8

天气气候预测中的不确定性是不可避免的。它一方面给用户或有关决策者带来很大的困难，同时也给科学工作者提出了新的研究课题。文章较为系统地评述了近几年出现的关于如何发展未来气象预测体系的若干观点，根据风险经济学和决策理论，构建了一个未来天气气候预测体系的概念模型。其主要思想是将气象预测过程同用户决策过程有机地结合起来，充分利用来自用户的知识和风险管理经验，形成一个相互作用协同发展的预测体系。  相似文献   

Application of ensemble kalman filter to geophysical parameters retrieval in remote sensing:A case study of kernel-driven BRDF model inversion   总被引：2，自引：0，他引：2  

QIN Jun  YAN Guangjian  LIU Shaomin  LIANG Shunlin  ZHANG Hao  WANG Jindi  LI Xiaowen 《中国科学D辑(英文版)》2006,49(6):632-640

Remote sensing can provide multi-spatial resolution, multi-temporal resolution multi-spectral band and multi-angular data for the observation of land surface. At present, one of research focuses is how to make the best of these data to retrieve geophysical parameters in conjunction with their a priori knowledge and simul-taneously consider the influence of data uncertainties on inversion results[1-5]. The essence of remote sensing lies in inversion. It is difficult to precisely retrieve parame…  相似文献   

两种气象绘图软件的对比及应用          下载免费PDF全文

乔春贵王国安  杨建民 《气象与环境科学》2007,30(B09):159-160

介绍了Surfer8．0和Grads（v1．8L11版本）两个等值线绘制软件的功能，根据不同的业务需要，可采用不同的绘图软件，以提高工作效率。  相似文献   

WZ25-20钻进机构操作系统的程序设计          下载免费PDF全文

邵建萍 《探矿工程》2007,34(9):56-59

介绍了应用单片机构成的一种钻进机构操作系统的程序设计。  相似文献   

A Janus-faced biodiversity change and the partiality of ecological knowledge in a world biodiversity hotspot in Ghana: Implications for biodiversity rehabilitation     

Louis Awanyo 《Geoforum》2007,38(4):739-751

The Gyamfiase-Adenya-Obom cluster of villages in the forest-savanna region of Ghana is located within one of Conservation International’s 34 “World Biodiversity Hotspots” of the most biodiversity-threatened regions of the world. In collaboration with local farmers in this area since 1993, the People, Land Management and Ecological Change Project in Ghana (PLEC-Ghana) has been working on promoting biodiversity rehabilitation to address problems of biodiversity change. This goal is expected to be achieved through agrobiodiversity or biodiversity-friendly agricultural practices. However, farmers’ employment of these practices has been lackluster, even while they acknowledge biodiversity changes, dominated by Chromolaena odorata and other herbaceous species, that are driving the decline in forests and their biodiversity. In interpreting the difficulties of biodiversity rehabilitation in Gyamfiase-Adenya-Obom, this study outlines the diverging ecological knowledge of non-residents/outsiders and local farmers about biodiversity change, which it describes as Janus-like with two diverging faces. One face of biodiversity change shows the detrimental impacts on biodiversity and its observers—non-residents/outsiders—insist on biodiversity rehabilitation that nurtures forests, and the growth and domination of tree species. The other face of biodiversity change shows its agronomic advantages and its observers—the local farmers—are skeptical of current biodiversity rehabilitation practices. Farmers see agronomic benefits in biodiversity change, in particular the benefit of faster soil regeneration within the predominant bush fallow system of farming. And as a result of this observation, farmers continue with practices that sustain a decline in forests and biodiversity. Based on social and ecological research that explores three biodiversity-friendly practices promoted by PLEC-Ghana (fallow management, mulching, and intensive weeding to protect tree seedlings), this article discusses the partiality of ecological perspectives that emphasize either face of biodiversity change but not both, and the implications for biodiversity rehabilitation.  相似文献   

基于MAPGIS的皮帕尔图     

陈文杰 《城市地质》2007,2(2):32-36

皮帕尔图是常用的地下水化学分类方法,使用Mapgis编制的皮帕尔图,可以利用GIS的编辑和查询功能,使用更加方便,本文介绍了在Mapgis平台绘制皮帕尔图的步骤,并用该方法分析了天津地区的地下水化学类型,体现了使用GIS成图的优势。  相似文献