首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Abstract

With the increasing importance of parallel computing, attention must be given to utilising these resources efficiently. This article describes an algorithm to use cooperating parallel processors to solve the problem of vector polygon overlay, one of the most computationally-intensive problems in the GIS arena. The basic algorithm, which is described here using natural language, is not specific to a particular parallel architecture but has elements that are best suited to particular configurations, namely distributed-memory Multiple Instruction stream Multiple Data stream (MIMD) architectures. The intention is to provide an algorithm which utilises the potential of such architectures by distributing the computational load over several cooperating processors.  相似文献   

3.
Abstract

This paper proposes a unique method for plotting field bearing locations, of the kind typically taken by wildlife biologists on free ranging species, directly on a computer-compatible habitat map. We show how to use a GIS data base to identify differential habitat use directly from the polygon formed by each set of bearings. A geometric algorithm is developed to interpret the bearings accurately. The technique avoids the most difficult errors associated with using point locations, namely those due to animal movement, and distance from receiver to transmitter, and is especially useful for habitat preference studies.  相似文献   

4.
ATLAS?GRAPHICS (Version 3.0).

AutoCAD (Release 9.0 with ADE+1, ADE+2 and ADE+3).

AutoSketch (Speed Enhanced Version 1.02).

NUMERICAL RECIPES FORTRAN. Numerical Recipes Software

SCIPLOT.  相似文献   

5.
Abstract

The multidimensional nature of many types of data in modern geography calls for creative and innovative approaches to their analysis. Statisticians have recently developed methods for exploring and visualizing large, multivariate datasets, but cartographers and geographers in general have only recently begun to integrate these methods for use with spatial and spatiotemporal datasets that are multivariate in character. This article will present an example of such an integration—an environment for visualization of health statistics—as a case study to demonstrate the philosophical and practical advantages of geovisualization systems for the exploration of complex spatiotemporal information. Emphasis is placed on the encouragement of creative thinking about geographic phenomena through the use of such data-rich graphical tools.

  相似文献   

6.
Abstract

The Sanders housing lawsuit in Pennsylvania provides a case study of how to incorporate current events into the teaching of cartography or population geography at the high school or college level. Settlement of the Sanders case resulted in the release of information about the segregation of public housing by race in the Pittsburgh area. The issues in the Sanders case were mapped using publicly-accessible data, illustrating how an authentic lesson can be created with a minimum of resources.  相似文献   

7.
《The Journal of geography》2012,111(3):113-118
Abstract

Mental image and place-preference maps of college students in Florida were created through a two-part lesson. The patterns revealed by these maps were linked to students' life experiences, census data on migration and income, and similar studies conducted in other states. Students prefer states with established migration links to Florida and better income/job opportunities. Because the maps could not be created without their input, students were wholly engaged in a lesson that uses concepts in population geography and cartography to fulfill several national geography standards.  相似文献   

8.
Volume 111 Index     
《The Journal of geography》2012,111(6):264-265
Abstract

Concepts related to alternative map projections can be difficult to explain to students given the diversity and complexity of available projections. Students frequently have trouble understanding how distortions caused by the choice of a projection can affect map readability and comprehension. Programs available for personal computers now provide geography and cartography instructors with a method for interactively educating students concerning the distortions associated with alternative map projections. Such software can be incorporated into laboratory assignments in introductory geography courses or in more advanced courses that deal with map design or thematic cartography.  相似文献   

9.

The co-ordinate system (x, y) for the triangular Christaller lattice is generalized by the addition of a third, dependent, z-axis. The extended system yields the lattice distances between lattice points, whereas the original system yields only the plane Euclidean distance.  相似文献   

10.
Abstract

An increased use of artistic literature as a resource in both teaching and research is evident in geography. With the growing interest of some scholars in the behavioral aspects of geography, traditional resources are being supplemented with more humanistic, subjective information sources. In historical geography, for example, literature is a particularly suitable resource for studies of man's role in past geographies and of human perception of past environments.1 Specialists in regional geography and area studies also have shown a growing appreciation of such sources.2 A parallel and related development has occurred in geographic education. In many different courses, but particularly in those dealing with regions, literature has become a recommended resource. The purposes of this paper are (1) to review the relevance of the novel as a resource for geographers and (2) to suggest that a current novel, Centennial, by James A. Michener,3 particularly warrants consideration for use in courses on the historical geography of the United States.  相似文献   

11.

In this paper we summarize five experiments that were designed to investigate how tactile maps contribute to the cognitive maps of people with visual impairments. In two experiments we demonstrated that tactile maps can contribute to peoples' ability to learn a route through an unfamiliar area. From the results of two further studies, we argue that compared to people with sight, people with visual impairments have greater difficulty encoding information from a map. We considered this directly in a fifth experiment by investigating how people with visual impairments search and learn a map. We found that they used less efficient strategies than people with sight. We conclude that tactile maps are an important source of geographical information when people need to learn about new environments, but we also point out that to benefit most from tactile maps people need to encode the map information as effectively as possible. As people with visual impairments do not always use the most appropriate encoding strategies we suggest that tactile map users might benefit from greater experience and training in map encoding strategies.  相似文献   

12.
《The Journal of geography》2012,111(3):119-126
Abstract

Maps are fundamental in geographic explanation and education, but as map-making becomes firmly entrenched in the GIS lab, it becomes harder for students to imagine how they can make maps for their papers. Students need to illustrate papers with maps: among other things, maps provide clarity, links to real places, and insights into patterns and context of phenomena discussed in student papers. A simple, quick, and aesthetically satisfying method for students to make their own maps is presented. This map making method can help students can think more creatively and geographically about their topics.  相似文献   

13.
Going beyond location: Thematic maps in the early elementary grades   总被引:1,自引:1,他引:0  
《The Journal of geography》2012,111(2):368-374
Abstract

Cartographic research has long suggested that preschool and early elementary children possess advanced mapping behaviors in terms of interpreting, making, and using locational and wayfinding maps. To improve instruction in geographic concepts, it is necessary to see if these advanced mapping behaviors apply to thematic or special purpose maps as well, as an understanding of these types of maps is integral to the five fundamental themes of geography. An experiment was conducted to evaluate the thematic mapping abilities of second-grade students. Students viewed maps at the neighborhood, city, and national scales displaying different types of symbolization and presented in a random order. Results indicated that the map tasks were appropriate for this age level, and a statistical test of reaction times did not identify a best symbol type or scale, as all were appropriate for this age level. Responses to discussion questions indicated the students also have the ability to describe spatial patterns. The interpretation of quantitative information on maps is within the ability level of second grade students, and materials currently used in second grade should be revised to include these maps.  相似文献   

14.
《The Journal of geography》2012,111(5):203-205
Abstract

Many student geography organizations or clubs associated with colleges and universities undertake community service projects each year to meet local needs and to gain recognition within the community. A uniquely geographical project of playground map painting provides a great community service and goes one step further by incorporating elements of quality service-learning for the geography club members. Painting projects for large school playground maps of the world, United States, or home state are student-planned and student-run. The final painted map can be used for geographic education in elementary schools by conveying basic spatial and geographic relationships. This article will detail a proven method of producing a colorful, useful playground map that can be employed by geography clubs as a service-learning activity and used by educators in elementary schools.  相似文献   

15.
多边形是GIS研究和应用中使用最频繁的几何对象,该文描述了基于简单要素模型的任意多边形分割算法。从计算几何出发,结合GIS空间数据的特点,将基于简单要素模型的多边形分割算法设计为:1)对多边形及分割线的边界排序,基于扫描线及外包矩形检测查找可能相交的线段,提高相交线段的搜索效率;2)计算交点生成结点信息(包括交点坐标、线号及交点的出入),并存储在独立的单向链表中;3)根据结点链表和原多边形坐标搜索结果多边形。该算法能够分割任意简单多边形(凹凸、曲线边界和带洞的多边形)以及有共享边的多边形。最后在MapGIS7.0平台上,实现了基于简单要素类的多边形分割功能。  相似文献   

16.
街网约束下的城市居民地自动综合算法   总被引:2,自引:0,他引:2  
街网约束下的城市居民地自动综合是地图综合中的一个难点,该文从居民地多边形化简、居民地合并等方面讨论街网约束下城市居民地自动综合算法,并研究综合操作后居民地与街道冲突的解决方法.由此实现的城市居民地自动综合功能用于实验数据中,对多边形形态的化简、合并及街道形态的保持都较无约束条件下的居民地综合更合理.  相似文献   

17.

Geographic Software Reviewed in this article:

LIFE TABLES and the LESLIE MATRIX. CONDUIT

MENTMAP2. Lawrence W. Carstensen Jr.

PC-MATLAB, Version 1.0. The Math Works, Inc.

QUICKMAP, version 1.0. Sammamish Data Systems, Inc.

SYSTAT: THE SYSTEM FOR STATISTICS, Version 2.1, Systat Inc.

USA DISPLAY. Instant Tecall  相似文献   

18.
Books Reviewed: Browning, Frank A Queer Geography: Journeys Toward a Sexual Self Fellows, Will Farm Boys: Lives of Gay Men from the Rural Midwest Rubenstein, James M. The Cultural Landscape: An Introduction to Human Geography. 6th ed Knox, Paul L. and Marston, Sallie A. Human Geography: Places and Regions in Global Context Kuby, Michael; Harner, John, and Gover, Patricia Human Geography in Action  相似文献   

19.
GPU加速的多边形叠加分析   总被引:2,自引:0,他引:2  
叠加分析是地理信息系统最重要的分析功能之一,对多边形图层进行叠加分析要花费大量时间。为此,将GPU用于多边形叠加分析过程中的MBR过滤及多边形剪裁两个阶段。对MBR过滤阶段,提出了基于GPU的通过直方图及并行前置和实现的MBR过滤算法。对多边形剪裁阶段,通过改进Weiler-Atherton算法,使用新的焦点插入方法和简化的出入点标记算法,并结合并行前置和算法,提出了基于GPU的多边形剪裁算法。对实现过程中可能出现的负载不均衡情况,给出了基于动态规划的负载均衡方法。通过对这些算法的应用,实现对过滤阶段及精炼阶段的加速。实验结果表明,基于GPU的MBR过滤方法相对CPU实现的加速比为3.8,而基于GPU的多边形剪裁的速度比CPU实现快3.4倍。整体上,与CPU实现相比,GPU加速的多边形叠加提供了3倍以上的加速比。  相似文献   

20.
Abstract

This paper offers a teaching strategy for incorporating TIGER/Line files into introductory GIS courses where IDRISI and OSUMAP are the primary software packages. TIGER/Line files present a valuable database for teaching GIS. The TIGER data structure aids in teaching concepts related to topological data structures, geocoding and address matching, and the files themselves provide an excellent database for laboratory exercises that incorporate census information along with environmental and natural resource data. Lack of support by commonly-used educational software packages to import TIGER/Line files directly has been a serious impediment in an instructional context. This paper presents software developed to convert TIGER/Line files into simple polygon vector files acceptable by IDRISI and OSUMAP for three alternative census geographic units (tracts, block groups and blocks). The resulting vector files are plotted for visual examination and graphical output. The vector files generated can also be imported into other GIS or computer mapping software packages.  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