排序方式： 共有48条查询结果，搜索用时 250 毫秒
31.
基于IDL的地形三维可视化实现 总被引：3，自引：0，他引：3
作为一种第四代的编程语言,IDL具有对海量数据进行获取、分析、可视化以及对多种图像进行处理和交互式操作的功能。在分析IDL的基础上,应用组件编程技术实现了对遥感图像和DEM数据进行地形三维合成及动态模拟的可视化系统设计,经对环境的三维再现和模拟,对生态环境的演变研究可以起到指导作用,而且它具有较好的系统维护和重复使用功能、易于扩展以及面向对象的特点。用该系统建立了吉林西部虚拟自然环境,对三维地形进行空间分析,及吉林西部生态环境数据库的空间和属性数据的查询。 相似文献
32.
Mark Wise 《Geoforum》2007,38(1):171-189
The political salience of demands from minority and regional groups for greater language rights increases across Europe. To draw more geographical attention to a particular aspect of these developments, this article identifies the main generic problems of converting demands for ‘linguistic rights’ into applied language policies. It does this by first outlining how the historic process of nation-state building in Europe reduced linguistic diversity, but has not eliminated language demands emanating from regional minorities. It then analyses how the concept of ‘linguistic rights’, as a part of human rights in general, has been developing within the United Nations and bodies including the Council of Europe and the European Union. Having outlined the political-legal frameworks within which minority language rights are pursued, the article then discusses the major difficulties of putting them into practice in particular places and spaces. They can be summarised as: the weakness of relevant international agreements; the dominance of state sovereignty in determining language policies; the limited public support for minority language rights; the difficulties of defining minority languages and delimiting the geographical spaces they occupy; the challenges posed by the growing geographical mobility of populations; and the problem of balancing collective and individual rights. Two fundamental issues linking these different problems are identified. First, there are problems of definition: what constitutes a ‘minority’ or ‘regional’ language and within what geographical space(s) is such a language spoken? This spatial dimension underlies a second fundamental problem, namely that of resolving conflicts between individual personality rights and collective territorial rights in increasing hybrid geolinguistic situations created by the growing geographical mobility of populations. Sociolinguists study these issues, but usually treat these essential spatial dimensions in a superficial fashion. Thus, there is an opportunity for geographers to develop more sophisticated geolinguistic analyses as a contribution to this interdisciplinary field. 相似文献
33.
分析了地理标记语言和矢量标记语言的各自特征，在此基础之上提出了一种从GML格式转换到VML格式的方法，实现了IE中矢量地图的直接显示。最后给出了实例验证。 相似文献
34.
35.
.net是微软提出的新一代因特网模型，介绍了基于.net模型的全新GIS体系结构g.net，着重地阐述了g.net的关键技术XML,g.net的结构和g.net上的数据源，展望了g.net的应用前景。 相似文献
36.
Andrew McGregor 《Geoforum》2004,35(5):593-606
This paper adopts the concept of `environmental imaginaries' to explore the influence of environmental discourses upon supporters of Australian environmental movements. Rather than investigate knowledge, values, attitudes or behaviour, as is often the focus of research into public environmentalism, this study analyses the presence, absence, influence and interactions of different environmental discourses at the interpersonal scale. The relative acceptability and familiarity of different environmental philosophies, with their radically different approaches to nature, has important impacts upon the political strategies, actions and directions adopted by environmental movements. Through conducting a series of ongoing discussion groups with self-identifying `environmentalists' it is found that nature is constructed predominantly through the language and concepts of sustainable development, although this discourse coexists with a number of concurrent and oppositional viewpoints. The power of sustainable development is self-sustained through the normalisation of particular languages and modes of expression. Alternative ideas and discourses are inhibited by a lack of language and familiarity and consequently disempowered and relegated to subordinate positions within discussions. The paper concludes by arguing that the lack of acceptance of alternative ecocentric ideas within the environmental community risks de-radicalising the movement and limits the diversity of political strategies and options that it could potentially adopt. 相似文献
37.
38.
薛长虹 《成都信息工程学院学报》1998,(4)
从高等院校数学课程教学模式的探讨入手,提出了数学课与计算机实验相结合的改革思想,并通过实践对开设数学实验课各个环节的合理定位作了详细的描述,主要采用Ｍａｔｌａｂ软件作为线性代数实验课的实验工具,辅助理论教学,开设数学实验课,并对开设实验课后的成效及尚存的问题进行了剖析。 相似文献
39.
??, ???????????GML??????????????????????????洢??????????????????????????????????????SQL???????SQL???????GML????????????????????,??????????????????XML????Ч???????GML??????????????????????,???,W3C??XQuery?????????XML??????????????????????????(GML??????????????)????????2????????о?????????NXD????????????????????????GML?????????????????????????XQuery????????????XQuery????????????????????????????????NXD??GML????????????????? 相似文献
40.
