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931.
Shi Wenzhong 《地球空间信息科学学报》2013,16(2):6-12
This paper presents a hybrid model for three-dimensional Geographical Information Systems which is an integration of surface- and volume-based models. The Triangulated Irregular Network (TIN) and octree models are integrated in this hybrid models. The TIN model works as a surface-based model which mainly serves for surface presentation and visualization. On the other hand, the octree encoding supports volumetric analysis. The designed data structure brings a major advantage in the three-dimensional selective retrieval. This technique increases the efficiency of three-dimensional data operation. 相似文献
932.
对传统GIS要素点、线面的分类方式及存在的问题进行了初步分析,并提出了解决的思路。 相似文献
933.
作为GIS的重要应用,地理底图的生产与空间信息可视化,一直是行业关注的焦点。传统的地图生产与可视化方法,大多以有坐标的点、线、面等简单几何要素的编绘为主要手段。随着公众对GIS需求的增加,一方面,迫切需要将大量没有明确经纬度坐标的信息,通过地理手段直观展现出来。另一方面,在个性化时代,使用GIS技术,跳出传统制图标准,更灵活地表示行业专题信息,给我们带来了新的挑战。 相似文献
934.
《International Journal of Digital Earth》2013,6(6):471-486
Spatial analysis, including viewshed analysis, is an important aspect of the Digital Earth system. Viewshed analysis is usually performed on a large scale, so efficiency is important in any Digital Earth application making these calculations. In this paper, a real-time algorithm for viewshed analysis in 3D scenes is presented by using the parallel computing capabilities of a graphics processing unit (GPU). In contrast to traditional algorithms based on line-of-sight, this algorithm runs completely within the programmable 3D visualization pipeline to render 3D terrains with viewshed analysis. The most important difference is its integration of the viewshed calculation with the rendering module. Invisible areas are rendered as shadows in the 3D scene. The algorithm process is paralleled by rasterizer units in the graphics card and by vertex and pixel shaders executed on the GPU. We have implemented this method in our 3D Digital Earth system with the DirectX 9.0c API and tested on some consumer-level PC platforms with interactive frame-rates and high image quality. Our algorithm has been widely used in related systems based on Digital Earth. 相似文献
935.
ALISON BARNES 《Geographical review》2013,103(2):164-176
For many geographers, the printed page is no longer a productive tool to engage contemporary definitions of place or debates surrounding the nonrepresentational. There is a discernible shift within the discipline toward creative research methods, including using media such as film or sound, with a perception that they are less “fixed” in nature. In this article, however, I suggest that, by developing “geo/graphic” work that draws on theories and practices from both cultural geography and graphic design, the page can be recast as a liminal space, a threshold between readers and their understanding and imagination. I propose that a book has the potential to offer a multisensory, interactive space of exploration for readers and that the construction of such geo/graphic work also offers researchers an additional creative method with which to understand place. 相似文献
936.
937.
Agnieszka Leszczynski 《The Professional geographer》2013,65(3):350-365
Heated exchanges between critical theorists and GIScientists over geographic information systems (GIS) in 1990s geography gave rise to calls for increased communication between critics and practitioners of the technology and most recently for “hybrid” qualitative–quantitative GIS practices. Although GIS scholars have successfully addressed mid-1990s critiques of the technology by developing a series of critical GIS practices that involve nuanced and reflexive deployments of GIS and assessments of its visual products, theoretical critiques of GIS remain fixated on the epistemological deficiencies of the technology. Despite references to loosening metaphysical tensions across the discipline, this difference in assessments reveals the discourses of critical-theoretic geography and GIScience to remain separated by a trenchant philosophical divide, across which ontological and epistemological commitments are inviolable. The inability to fully reconcile a critical–theoretic epistemology with the explicitly ontological metaphysics of GIS further complicates qualitative engagements with the technology by addressing a series of inconsistencies into GIS praxis arising from the quantitative limits to representation encountered in the formal universe of computing. The persistence of metaphysical tensions in critical engagements with the technology questions the degree to which qualitative methods can be seamlessly hybridized with the quantitative architectures of GIS. 相似文献
938.
《The Professional geographer》2013,65(4):487-488
Book Reviewed in this article: Geographical Aspects of Health and Disease in India. Rais Akhtarand A.T.A. Learmonth, eds. Antarctic Treaty System: An Assessment. Proceedings of a Workshop at Beardmore South Field Camp, Antarctica. American Electoral Mosaics. J. Clark Archerand Fred M. Shelley. Kompas op Suidwes-Afrika/Namibie. W.S. Barnard, ed. Jerusalem in the 19th Century: The Old City. Yehoshua Ben-Arieh. The World as a Total System. Kenneth E. Boulding. A Social History of Housing 1815–1985, Second Ed. John Burnett. Human Migration. W.A.V. Clark. Regional Population Projection Models. Andrei Rogers. The State of Population Theory: Forward from Malthus. David Colemanand Roger Schofield, eds. Imagining Tomorrow: History, Technology and the American Future. Joseph C. Corn, ed. Swidden Agriculture in Indonesia: The Subsistence Strategies of the Kalimantan Kantú. Michael R. Dove. Glacial Geologic Processes. David Drewry. Physics of Desertification. Farouk El-Bazand M.H.A. Hassan, eds. Housing the Homeless. Jon Ericksonand Charles Wilhelm, eds. Settlement Patterns in Missouri: A Study of Population Origins, with a Wall Map. Russel L. Gerlach. Desert Development: Man and Technology in Sparselands. Yehuda Gradus, ed. Nuclear Winter. The Evidence and Risks. Owen Greene, Ian Percivaland Irene Ridge. The Take-off of Suburbia and the Crisis of the Central City. Günter Heinritzand Elisabeth Lichtenberger, eds. Regional Input-Output Analysis. Geoffrey J. D. Hewings. Spatial Transportation Modeling. Christian Werner. The Atlas of Georgia. Thomas W. Hodlerand Howard A. Schretter, eds. Latin America. 5th ed. Preston E. Jamesand C.W. Minkel. Applied Remote Sensing. C.P. Lo. Localities, Class, and Gender. The Lancaster Regionalism Group. Urban Social Movements: The City after Castells. Stuart Lowe. Politics and Method. Doreen Masseyand Richard Meegan, eds. Land Use. A. S. Mather. The Kingdom of Coal. Donald L. Millerand Richard E. Sharpless. The Presidio and Militia on the Northern Frontier of New Spain, A Documentary History, Vol. 1: 1570–1700. Thomas H. Naylorand Charles W. Polzer, S.J., comps. andeds. Nuclear Power: Siting and Safety. Stan Openshaw. The Central African Republic: The Continent's Hidden Heart. Thomas O'Toole. Environmental and Dynamic Geomorphology. Márton Pécsi, ed. Remote Sensing Principles and Interpretation. Floyd F. Sabins, Jr. Acid Rain and Friendly Neighbors: The Policy Dispute between Canada and the United States. Jurgen Schmandtand Hilliard Roderick, eds. Earth's Changing Surface: An Introduction to Geomorphology. M.J. Selby. International Migration: The Female Experience. Rita J. Simonand Caroline B. Brettell, eds. On Geography and Its History. D.R. Stoddart. Transportation Networks: A Quantitative Approach. D. Teodorovic. Processes in Physical Geography. R.D. Thompson, A.M. Mannion, C.W. Mitchell, M. Parry, J.R.G. Townshend. Imaging Radar for Resources Surveys. J.W. Trevett. Dominance and Affection: The Making of Pets. Yi-Fu Tuan. Capturing the Horizon. The Historical Geography of Transportation since the Transportation Revolution of the Sixteenth Century. James E. Vance, Jr. Nations at Risk: The Impact of the Computer Revolution. Edward Yourdon. 相似文献
939.
Alan T. Murray Daoqin Tong 《International journal of geographical information science》2013,27(7):757-776
Facility placement and associated service coverage are major concerns in urban and regional planning. In this paper an approach is detailed for the problem of covering spatial demand for service, where potential facilities are located in the continuous plane. It is shown that weighted demand, represented as points, lines or polygons, can be optimally served by a finite number of potential facility locations, called the polygon intersection point set (PIPS). The developed approach is an extension of a point‐based abstraction of demand to more general representations (e.g. points, lines or polygons). An empirical analysis of warning siren siting in Ohio is carried out, highlighting the applicability of this approach. 相似文献
940.
Jida Wang 《International journal of geographical information science》2013,27(2):229-253
Urbanization is an important issue concerning diverse scientific and policy communities. Computational models quantifying locations and quantities of urban growth offer numerous environmental and socioeconomic benefits. Traditional urban growth models are based on a single-algorithm fitting procedure and thus restricted on their ability to capture spatial heterogeneity. Accordingly, a GIS-based modeling framework titled multi-network urbanization (MuNU) model is developed that integrates multiple neural networks. The MuNU model enables a filtering approach where input data patterns are automatically reallocated into appropriate neural networks with targeted accuracies. We hypothesize that observations classified by individual neural networks share greater homogeneity, and thus modeling accuracy will increase with the integration of multiple targeted algorithms. Land use and land cover data sets of two time snapshots (1977 and 1997) covering the Denver Metropolitan Area are used for model training and validation. Compared to a single-step algorithm – either a stepwise logistic regression or a single neural network – several improvements are evident in the visual output of the MuNU model. Statistical validations further quantify the superiority of the MuNU model and support our hypothesis of effective incorporation of spatial heterogeneity. 相似文献