道路网络示意图的多边形生长算法

道路网络示意图是实体网络的抽象表示,因其更加符合人的认知习惯,在地图服务与地图制图领域已得到初步应用。以路径为单位的网络示意图自动生成算法只顾及节点与线段的局部布置,且较难以维护网络拓扑一致性。本文以闭合多边形(网眼)为基本单位,利用网眼的独立性与邻接性,提出了多边形生长算法,核心思想是将道路网络分类为闭合多边形与非闭合线段,以闭合多边形提取、映射、优化为主线,辅助组合非闭合线段。算例分析验证,本算法在网络均衡分布及拓扑一致性方面具有优势。     

基于SVG的专题地图与Google地图混搭研究

Google地图开放API后,将Google地图作为地理底图,由用户定制专题要素成为专题地图制作的一种新形式。文中研究如何在Google地图上制作精美生动的网络专题地图。SVG用于表达网络专题要素有其独特的优势,文中结合SVG的优点探讨以Google地图为地理底图的网络专题地图的表达、设计与实现方法,尝试解决网络地理底图与专题要素的一致性表达问题。     

全景景观地图的计算机辅助制作

针对全景景观地图制作过程复杂、效果差等问题,该文研究了全景景观地图计算机辅助制作的关键技术,包括渐进式投影的地形几何弯曲算法、地形高程垂直夸张、地物模型配置的滚落线生成算法等;完善了全景景观地图的机助制图过程和方法,提高了全景景观地图制图的效率,最后实现了全景景观地图制图原型系统。     

School Students' Understanding of Choropleth Maps: Evidence From Collaborative Mapmaking Using GIS

Abstract

Pairs of students from two age groups made choropleth maps using Arc View. Evidence from their discourse is used to assess aspects of their cartographic understanding as well as the nature of their collaboration. Students from both age groups spent a high percentage of their time talking about cartographic strategy and a low percentage of time on technical aspects of GIS functionality. Older students engaged in more reasoning and questioning. Key areas for teacher intervention include promoting better student understanding of what the mapped data mean (including directionality and numerical characteristics) and the most effective strategies for raising the level of students' conceptual exchange during collaborative learning.     

The Importance of Geography in Education II

Abstract

The concept of scale is fundamental to geography, yet the definitions for “scale” and related spatial terms can be confusing to those working in other spatial science disciplines. This is particularly true in the emerging multidisciplinary world of integrated remote sensing and geographic information systems, or IGIS's, where data of different types and at various spatial and temporal scales are combined to support complex space-time data analyses. Without a basic lexicon of accepted scale terms, working within an IGIS can breed confusion in the interpretation of data and the models that result from an IGIS construct. This paper provides some terminologies of scale that can be used as a framework for a multidisciplinary lexicon of accepted scaling terms and describes their relationships to an IGIS. It also illustrates how scaling terms can be potentially misunder stood when applied to geographic techniques that are used in disciplines related to geography.     

Building Environmental Literacy through Participation in GIS and Multimedia Assisted Field Research

Abstract

A Learning Support System (LSS) that emphasizes experiential research in natural environments using the cutting-edge technologies of GIS and multimedia has been developed for teaching environmental literacy to undergraduate students at the University of Georgia. Computers are used as cognitive tools to create a context in which students become interns in an ecological research center. Students are instructed to conduct research in the form of two field laboratories (the stream and forest laboratories). They accomplish their tasks by collecting data in the field (the State Botanical Garden of Georgia near the campus). They enter the data in the Learning Support System (LSS), and are guided to formulate hypotheses relating to stream water quality and human impact on forest succession for testing. Students also interact with the Environmental Research Support Site (ERSS) within the LSS for explanations to their findings. A specially customized Arc View GIS program within the LSS provides a tool to students for spatial analysis in the case of the forest laboratory. Students and faculty evaluations as well as final examination results confirmed the receptiveness of students to the LSS approach and its effectiveness in the learning of environmental literacy.     

Transportation Part II

Abstract

This article presents research on evaluating problem-based learning using GIS technology in a Singapore secondary school. A quasi-experimental research design was carried to test the PBL pedagogy (PBL-GIS) with an experimental group of students and compare their learning outcomes with a control group who were exposed to PBL but not GIS. The results show significant differences in the learning outcomes between the two groups. Specifically, students in the control group show more memorization skill while students in the experimental group demonstrate more analytical and evaluation skills. The conclusion is that learning with PBL-GIS pedagogy can result in higher-order learning outcomes.     

Paper versus Pixel: Effectiveness of Paper versus Electronic Maps To Teach Map Reading Skills in an Introductory Physical Geography Course

Abstract

This article addresses the lack of outcome-based research on the integration of technology into pedagogy at the undergraduate college level. It describes a study performed at a Midwestern university, testing the relative effectiveness of paper and electronic topographic maps for teaching map-reading skills, and considers the relationship between learning styles and paper or digital map preference. Results indicate that, although student map skill performance did not differ significantly with the use of paper or electronic maps, students preferred paper maps. Neither their performance nor their preferences were related to learning style. The article discusses the significance of these findings.     

The Valley of Chin lee

Abstract

This paper is concerned with an instructional design for the teaching of landform geography. A sequence of organizational problems is examined and suggestions made from a previous study of the southern peninsula of Michigan. Considerations of grid design, selection of terrain parameters, and the problem of regional definitions are assessed from both the historic point of view and the results of the pilot study. Of three basic landform parameters, i.e., average elevations, local relief, and average slope, the single criterion of elevation is advocated for the detection of regional homogeniety over large topographic surfaces. However, the use of local relief as a measure of surface texture is proposed for the delineation of individual terrain compartments. Suggested for all age levels above the elementary school, this project is a feasible design for an oft-neglected aspect of physical geography.     

Identification of cryovolcanism on Titan using fuzzy cognitive maps

Future planetary exploration of Titan will require higher degrees of on-board automation, including autonomous determination of sites where the probability of significant scientific findings is the highest. In this paper, a novel Artificial Intelligence (AI) method for the identification and interpretation of sites that yield the highest potential of cryovolcanic activity is presented. We introduce the theory of fuzzy cognitive maps (FCM) as a tool for the analysis of remotely collected data in planetary exploration. A cognitive model embedded in a fuzzy logic framework is constructed via the synergistic interaction of planetary scientists and AI experts. As an application example, we show how FCM can be employed to solve the challenging problem of recognizing cryovolcanism from Synthetic Aperture Radar (SAR) Cassini data. The fuzzy cognitive map is constructed using what is currently known about cryovolcanism on Titan and relies on geological mapping performed by planetary scientists to interpret different locales as cryovolcanic in nature. The system is not conceived to replace the human scientific interpretation, but to enhance the scientists’ ability to deal with large amounts of data, and it is a first step in designing AI systems that will be able, in the future, to autonomously make decisions in situations where human analysis and interpretation is not readily available or could not be sufficiently timely. The proposed FCM is tested on Cassini radar data to show the effectiveness of the system in reaching conclusions put forward by human experts and published in the literature. Four tests are performed using the Ta SAR image (October 2004 fly-by). Two regions (i.e. Ganesa Macula and the lobate high backscattering region East of Ganesa) are interpreted by the designed FCM as exhibiting cryovolcanism in agreement with the initial interpretation of the regions by Stofan et al. (2006). Importantly, the proposed FCM is shown to be flexible and adaptive as new data and knowledge are acquired during the course of exploration. Subsequently, the FCM has been modified to include topographic information derived from SAR stereo data. With this additional information, the map concludes that Ganesa Macula is not a cryovolcanic region. In conclusion, the FCM methodology is shown to be a critical and powerful component of future autonomous robotic spacecraft (e.g., orbiter(s), balloon(s), surface/lake lander(s), rover(s)) that will be deployed for the exploration of Titan.