首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   56篇
  免费   1篇
  国内免费   3篇
测绘学   51篇
大气科学   7篇
地质学   1篇
海洋学   1篇
  2018年   1篇
  2013年   53篇
  2012年   1篇
  2006年   1篇
  2005年   1篇
  2003年   2篇
  2000年   1篇
排序方式: 共有60条查询结果,搜索用时 46 毫秒
1.
Mapping spatial change is a fundamental theme in geography. The analytical and numerical application of differential calculus to continuous geographic data produces first-derivative distributions that can be mapped to show gradient magnitude and gradient direction, and second-derivative measures that can be mapped to show the form (convexity, concavity) of the geographic surface. When these differential measures are obtained for spatially distributed temporal data, a velocity/acceleration change map can be constructed. Cartographic applications of the methodology presented in this paper include slope and curvature landform mapping, derivative trend-surface mapping of urban housing value gradients and the velocity/acceleration mapping of mobile-home residency in the United States from 1950 to 1980.  相似文献   
2.
Abstract

Innovations for the British Army during World War I included use of a military geologist to compile 'water supply' maps and to guide well drilling. Between June 1915 and November 1918, W. B. R. King served as a staff lieutenant at General Headquarters of the British Expeditionary Force deployed on the Western Front. He pioneered British development of water supply maps for parts of Belgium and northern France, in several different styles and at scales of 1 : 100 000, 1 : 250 000 and 1 : 40 000. These assisted planning for advances into enemy-occupied territory or the development of water supply infrastructure within the region held ultimately by five British armies: in total about 1,500,000 men with some 500,000 horses and mules, each man/animal requiring on average 10 gallons (45 L) per day of potable water. The maps guided emplacement of over 470 military boreholes to supply drinking water to British forces, especially in provinces underlain by Cretaceous Chalk: Picardy and Artois. German forces also made use of military geologists at the Front, but in much greater number: up to about 300 in total. Water supply tasks were given high priority, and German water supply maps were finally standardized like other medium scale German geotechnical maps at 1 : 25 000. Six geologists were deployed with the American Expeditionary Force late in the war, and for their sector of the Front compiled at least two water supply maps at 1 : 80 000, and 11 at 1 : 50 000 that were supported by explanatory reports. Wartime imperatives thus generated expertise in hydrogeology that became available for civilian use post-war, and laid the foundation for further military development during World War II.  相似文献   
3.
《The Cartographic journal》2013,50(2):104-114
Abstract

This paper presents a technique for creating oblique view maps of urban areas. We identify and apply cartographic and cognitive principles to develop a solution in the context of state-of-art geographic information systems. The gap in the ability of these systems to render three-dimensional buildings into maps is addressed. At the core of our solution is a building facade modelling approach that supports varying degrees of abstraction. This is achieved by introducing a concept of 'facade waveforms' and representing building facades as combinations of these waveforms. A Fourier series approximation of the waveforms is used during the rendering processes resulting in an elegant solution to anti-aliasing. The formulation retains the semantic information in the representation that enables meaningful extensions like night time facade generation. The solution is implemented as a pixel shader and therefore leads to a large reduction in texture memory requirement compared with existing building rendering techniques. Additionally, in the case of web based systems, there is significant reduction in bandwidth requirement. We highlight the features of the proposed solution by generating demonstrative maps and images.  相似文献   
4.
We present new methods for analyzing geo-referenced statistical data. These methods combine visualization and direct manipulation techniques of exploratory data analysis and algorithms for data mining. The methods have been implemented by integrating two hitherto separate software tools: Descartes for interactive thematic mapping, and the data mining toolbox Kepler. In using these tools, data analysis may proceed as a steady interaction between visual inspiration and insights gained from mathematical–statistical calculations. After introducing the various components of the methods and tools, the paper guides the reader through in-depth examples of using the tools in the context of analysis of urban demographic data. In particular, it is shown how geography-based classifications of urban districts can be related to available thematic characteristics by applying the data mining algorithms classification tree derivation, attribute weighting, and subgroup discovery.  相似文献   
5.
We provide a research agenda for the International Cartographic Association's Commission on Visualization and Virtual Environment Working Group on Cognitive and Usability Issues in Geovisualization. Developments in hardware and software have led to (and will continue to stimulate) numerous novel methods for visualizing geospatial data. It is our belief that these novel methods will be of little use if they are not developed within a theoretical cognitive framework and iteratively tested using usability engineering principles. We argue that cognitive and usability issues should be considered in the context of six major research themes: 1) geospatial virtual environments (GeoVEs); 2) dynamic representations (including animated and interactive maps); 3) metaphors and schemata in user interface design; 4) individual and group differences; 5) collaborative geovisualization; and 6) evaluating the effectiveness of geovisualization methods. A key point underlying our use of theoretical cognitive principles is that traditional cognitive theory for static two-dimensional maps may not be applicable to interactive three-dimensional immersive GeoVEs and dynamic representations—thus new cognitive theory may need to be developed. Usability engineering extends beyond the traditional cartographic practice of "user testing" by evaluating software effectiveness throughout a lifecycle (including design, development, and deployment). Applying usability engineering to geovisualization, however, may be problematic because of the novelty of geovisualization and the associated difficulty of defining the nature of users and their tasks. Tackling the research themes is likely to require an interdisciplinary effort involving geographic information scientists, cognitive scientists, usability engineers, computer scientists, and others.  相似文献   
6.
This paper sketches the broad outlines of the practices of map publishers, industrial concerns, motor clubs, and state governments to convince Americans to become motoring tourists and, hence, to consume the goods, services, and landscapes these interests wished to promote. Their efforts were rooted in the promotional mapping of American railroads during the nineteenth century and in bicycle mapping. Yet, the particular demands of automobile travel, including long-distance navigation under the control ofthe travelers themselves, argues for an almost unique dependence on maps, which in turn gave road maps considerable value as promotional tools.  相似文献   
7.
Depending on scale, topographic maps depicting the shape of the land surfaces of the Earth are produced from different data sources. National topographic maps at a scale of 1:25 000 (25K maps) produced by General Command of Mapping are used as the base map set in Turkey. This map set, which consists of approximately 5500 sheets, covers the whole country and is produced using photogrammetric methods. Digital Elevation Models (DEMs) created from these maps are also available. Recently, another data source, Synthetic Aperture Radar (SAR) interferometric data, has become more important than those produced by conventional methods. The Shuttle Radar Topography Mission (SRTM) contains elevation data with 3 arc-second resolution and 16 m absolute height error (90 percent confidence level). These data are freely available via the Internet for approximately 80 percent of the Earth's land mass. In this study, SRTM DEM was compared with DEM derived from 25K topographic maps for different parts of Turkey. The study areas, each covering four neighboring 25K maps, and having an area of approximately 600 km2, were chosen to represent various terrain characteristics. For the comparison, DEMs created from the 25K maps were obtained and organized as files for each map sheet in vector format, containing the digitized contour lines. From these data, DEMs in the resolution of 3 arc-second were created (25K-DEM), in the same structure as the SRTM DEM, allowing the 25K-DEMs and the SRTM DEM to be compared directly. The results show that the agreement of SRTM DEM to the 25K-DEM is within about 13 m, which is less than the SRTM's targeted error of 16 m. The spatial distribution of the height differences between SRTM-DEM and the 25K-DEM and correlation analysis show that the differences were mainly related to the topography of the test areas. In some areas, local height shifts were determined.  相似文献   
8.
This paper describes a new approach called kriskogram to visualizing migration flows. To create a kriskogram, geographical units are projected as a set of points on a straight line segment called a location line. The migration flow between two points on the location line is represented using a half-circle drawn from the origin to the destination in a clockwise direction. Translucent symbols and a classification scheme can be used to make a kriskogram more effective. We demonstrate this method using a set of interstate migration data of four time periods for the conterminous United States.  相似文献   
9.
Most urban green space research focuses on the social benefits of parks and recreational areas. However, in areas with high levels of resource deprivation and physical disorder, parks may function as criminal marketplaces. Parks in such areas may cease to provide net benefits to the surrounding community and instead serve as a vector for criminal activity. Parks in eastern Kansas City, Kansas, are examined in terms of the probability of criminal marketplaces and beneficial social contribution. Variables for resource deprivation and social disorder are calculated for the study area and compared to national aggregates to identify which parks may behave as criminal marketplaces. In such cases, parks should exhibit an inverse relationship between distance from a park and number of criminal offenses per acre. Evaluating the incidence of crime near parks using geographic information systems (GIS) buffer analysis, proximity analysis, and spatial statistics demonstrates that parks in areas of extreme resource deprivation do not serve beneficial social roles, and some parks contradict conventional criminal justice and urban economic theory.  相似文献   
10.
Island cartography deals with special cartographic problems confronted in the portrayal of island regions and demands the use of specially developed software tools. One of the most commonly faced problems is the need of inset map creation for very small islands, and sometimes isolated ones, that must be displayed in the main map. This paper presents the methodology followed for the development of the Inset Mapper (IM) Software toolbox, describes the toolbox, and showcases its ability to create inset maps in Island regions. The IM software tool provides a useful cartographic tool for assisting the selection of the most appropriate position and scale of the inset map in an Island region.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号