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Table of Content

    24 December 2001, Volume 20 Issue s1 Previous Issue    Next Issue
    Original Articles
    Research on the Index System and Knowledge Rules for Geographic-Feature-Oriented Generalization
    QI Qing-wen, JIANG Li-li
    2001, 20 (s1):  1-13.  doi: 10.11820/dlkxjz.2001.s1.001
    Abstract ( )   PDF (722KB) ( )   Save
    This paper expounded the author’s research on the index system and knowledge rules for Geographic - Feature - Oriented Generalization, and an example of its application. The research approach is the integration of geo-science analysis & conclusion, map analysis, expert consulting, as well as GIS &. RS spatial analysis method, to extract, conclude and build them. The index system include three types as data, literal and graphic index , and on the other hand grouped by database generalization index and map visualization index. The knowledge rules include, in crosswise, geometric, structure and procedure knowledge, and in lengthways, the knowledge of geographic feature description, operator selection, algorithm selection, as well as specific geo-object oriented and specific region oriented knowledge. In the knowledge base, these knowledge rules are organized by three dimension of variables as generalization condition, generalization scope/level, and generalization actions. The example is the generalization of The Map of Transportation Network in Zhujiang Delta Economic Zone.
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    Research on Extended-Fractal Based Automatic Map Generalization
    WU He-hai
    2001, 20 (s1):  14-28.  doi: 10.11820/dlkxjz.2001.s1.002
    Abstract ( )   PDF (753KB) ( )   Save
    The Fractal method, which is originated from geo-sciences, has been widely applied in various sciences and disciplines. This paper, however, concentrates on the essence of its application, i.e. , how much information it can provide for us, what limit it has, how it can be combined with other methods, in map generalization. Several issues related to the application of Extended Fractal in automatic map generalization is expounded.
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    The Basic Principles and Methods of Geo-informatic Complex Mapping
    LIAO Ke
    2001, 20 (s1):  29-38.  doi: 10.11820/dlkxjz.2001.s1.003
    Abstract ( )   PDF (668KB) ( )   Save
    This paper deals with the connotation and significance, theoretical foundation and basic link of Geo-informatic complex mapping, and relates different representative formality, design principles and mapping methods of complex map, comprehensive series maps and complex atlas. Then, it deals with the principles and methods of unity and concert on complex mapping, and emphasizes on related unity and concert on aspects of scientific contents with graded, classified and legend as well as outline and boundary, and methods and measures of unity and concert on other aspects. Finally, analyses the new development of complex mapping in aspects of science and technology in the environment of computer mapping and GIS.
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    Design And Development of the Electronic Version of National Physical Atlas of China
    QI Qing-wen, CHI Tian-he, LIAO Ke, LI Bo-nan, CHEN Hua-bin, ZHA Chun-li
    2001, 20 (s1):  39-45.  doi: 10.11820/dlkxjz.2001.s1.004
    Abstract ( )   PDF (496KB) ( )   Save
    This paper expounded theories, methods and technologies of the Electronic version of National Physical Atlas of China (ENPAC). At first, the background of, the need to, and the support from CAS to, the ENPAC is related. Secondly, the authors discussed the designing principles and some theoretic & methodological problems of ENPAC. Thirdly, the paper described the system structure and key problems of ENPAC. The system structure of it includes data, software, auxiliary materials, model and methods, and also its four functions, i. e. , the function module of atlas browsing, display and simulation, query, as well as analysis. The key problems includes the selection of developing platform, the building of 3D and dynamic data model, and also integration of multi - source & multi - type data. Fourthly, the paper analyzed main characteristics of ENPAC, i. e. , the unique interface structure, the special interactive tools, various types of dynamic maps, special browsing function, vivid virtual 3D relief fly - through, multiple representation, as well as function of analysis and query. Finally, future direction and plan of updating ENPAC was expounded.
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    The Design and Development of Internet Version of National Physical Atlas of China
    CHI Tian-he, QI Qing-wen, LIAO Ke, WANG Lei
    2001, 20 (s1):  46-51.  doi: 10.11820/dlkxjz.2001.s1.005
    Abstract ( )   PDF (403KB) ( )   Save
    This paper described several points in designing and developing the Internet Version of National Physical Atlas of China (NPAC), including conceptual designing, WebGIS technology and strategy in development, main functions and characteristics, as well as maintenance and data updating of the system. As for the conceptual designing, the system consists of three parts, i. e. , software of server, software of browser, and support of NPAC database. The technology and strategy of the system includes the strategy of concentrating both server end and client end, the browser technology based on Java Applet , and the server technology based on Map Object. The functions and characteristics of the system includes five points, i. e. , scientific and logic structure of the content, clear and concise interface, special information query function, multiple representation of maps, and functions of spatial information analysis and mapping. In the scheme of system maintenance and data updating, the paper expounds from three points on, i. e. , network technology, data updating, and function expanding.
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    Information Classifications and Coding Systems of Database for the National Physical Atlas of China
    ZHU Che
    2001, 20 (s1):  52-62.  doi: 10.11820/dlkxjz.2001.s1.006
    Abstract ( )   PDF (565KB) ( )   Save
    Based on THE NATIONAL PHYSICAL ATLAS OF CHINA, this paper features the establishment of information classifications and coding systems of database for China’s physical atlas, stressing their classifying principles and subsystems. It so follows that code lists, coding designs, coding standards and structures of thematic code are formulated , and that technical flowcharts, physical data-layers, meta-data bases, and data lexicons are illustrated in terms of database for China’s physical atlas.
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    Spatial Cognition Research on Electronic Maps
    CHEN Yu-fen
    2001, 20 (s1):  63-68.  doi: 10.11820/dlkxjz.2001.s1.007
    Abstract ( )   PDF (432KB) ( )   Save
    Spatial cognition research on electronic maps is an important research content of map spatial cognition theory. This paper firstly presents the concepts and the characteristics of electronic maps, then, analyzes the necessity of spatial cognition research on electronic maps. Based on the above, the paper introduces the characteristics and the main contents of spatial cognition research on electronic maps.
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    Research of geographic Spatial Database
    WANG Yu-xiang, ZHANG Yan, YANG Chong-jun
    2001, 20 (s1):  69-77.  doi: 10.11820/dlkxjz.2001.s1.008
    Abstract ( )   PDF (534KB) ( )   Save
    In this article, properties of geographic spatial database are analyzed. Then an algorithm of R+_tree spatial index is implemented for spatial index, to improve the spatial search efficiency. At last, an example of spatial database is given.
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    Design Principles of Webmap
    CHEN Yu-fen, LIAO Ke, JIANG Nan
    2001, 20 (s1):  78-87.  doi: 10.11820/dlkxjz.2001.s1.009
    Abstract ( )   PDF (650KB) ( )   Save
    A webmap is a kind of map which be browsed, made and used on the World-Wide-Web. Along with the popularization of Internet, a webmap, as a form of spatial information visualization, has been paid more and more attention to. A webmap has charac-teristics with dynamism, interactivity, hypermedia structure and faster distribution, and has functions with graphics operation, map query, interactive mapping, statistics and analysis, and hyperlink web page. Presently, most webmaps are made by program developers in computer company, and less cartographers participate in the mapping, so there are some problems exist on the display effects of webmaps from the angle of cartographic design and affect the information communication of webmaps. Based on the analysis of some cartographic web sites like http://www. go2map. com, http://www. chinaquest. com, http://www. map960. com, http://www. afmap. com, http://www. fhoo. com, http://www. mapquest. com and http://www. atlas, ccrs. nrcan. gc. ca, the authors summarize the characteristics and functions of webmap, then present the principles of webmap design including interface design, color and symbol design, and layer design according to the authors’ design experiences in the both paper maps and electronic maps. The authors believe that researches on webmap design are helpful to improve the display effects of webmaps and enhance efficiency of information communication. Farther researches on webmap design should be carried out from the viewpoint of cognitive science and user-centered.
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    Invariant Features Extraction of Map Symbols
    YE Jian-kao, LIU Yue
    2001, 20 (s1):  88-94.  doi: 10.11820/dlkxjz.2001.s1.010
    Abstract ( )   PDF (384KB) ( )   Save
    Feature extraction is the key of automated recognition of map symbols. Four two-dimensional invariant features of map symbols are summarized. The methods of the extraction of invariant features and a part of the experiment results are put forward.The four invariant features are the degree of complication of the periphery of the symbols , the breadth length ratio of the symbols, the proportion between the black pixels andall the pixels of a symbol, and the distance between the barycenter and the geometry center of a symbol.These four invariant feature parameters are characterized by invariability of rotation and size. A part of invariant characters has been proved in the paper. They are easy to be picked-up and the calculation is very simple.From the results of the experiment, we can see that the four feature parameters com-mendably describe the characters of the point symbols on maps, and they are not influenced by changing the size of scanning maps or rotating symbols and not disturbed by any noise of the image.The correctness ratio of automated recognition of point symbols on a map could be greatly increased through extracting and analyzing these four feature parameters.
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    Some Key Technologies of MGE-based Digital Mapping System
    QI Qing-wen, ZHAO Xiao-cheng, WANG Feng-man, BAI Lian-di
    2001, 20 (s1):  95-105.  doi: 10.11820/dlkxjz.2001.s1.011
    Abstract ( )   PDF (745KB) ( )   Save
    On the bases of summarizing the functions, features and current status of digital map technologies, this paper analyzed the structure, technical workflow and characteristics of MGE digital mapping system. Then, the authors expounded some key technologies of MGE-based digital mapping system, such as data input and digitizing, color base and symbol base generation, map editing and color separation, as well as mutual conversion between printed maps and electronic maps. These technologies are very important to map designing, editing, plating, etc. Finally, the future of digital map integrated system are foreseen.
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    Study of Fujian Province Government Information Sharing Platform
    WANG Lei, CHI Tian-hei, Wang Qin-min, Chen Chong-cheng
    2001, 20 (s1):  106-112.  doi: 10.11820/dlkxjz.2001.s1.012
    Abstract ( )   PDF (475KB) ( )   Save
    During the construction of Digital Fujian, government department need the information sharing between each other, particularly about large-scale basic spatial information and public information. Based on the wide band of Fujian government, the government information sharing platform will build government department information sharing system. This paper talks about the construction objective, function and key technology of this system.
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    The Theory and Method of Agricultural Expert Decision Support System
    LIANG Qi-zhang, LI Ju-zhang
    2001, 20 (s1):  113-120.  doi: 10.11820/dlkxjz.2001.s1.013
    Abstract ( )   PDF (606KB) ( )   Save
    This paper expounds the theory and methods of Agricultural Expert Decision Support System based on the authors’ research and practice experiences. The objective of the system is to set up optimum scheme on agricultural structure for the base units’ leaders. The key technologies are the computer simulation on agricultural development planning , the multi-standard evaluation models for agricultural structure, the agricultural investment evaluation models, the agriculture expert system, the strategy and method of a-gricultural transportation and storage, the interface for the agricultural expert decision support system, as well as the dynamic analysis and mapping for agricultural development.
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    The Research on COM-based Constructing WebGIS Technique
    CHEN Hua-bin, CHI Tian-he
    2001, 20 (s1):  121-136.  doi: 10.11820/dlkxjz.2001.s1.014
    Abstract ( )   PDF (4487KB) ( )   Save
    The rapid advance of networking and componentization technology is one of the most important characteristics in software development in recent year. The main breakthrough in software technology is in software cooperation and componentization. Based on the achievement of relative study home and abroad,this paper introduces the combination of COM technology and WebGIS. Arming at the particularity of GIS, this paper describes the necessity, feasibility, common process and main task of using COM to construct WebGIS. At last, this paper describes how to import COM technique to the field of WebGIS in order to improve the level of WebGIS technique and work efficiency, utilize the efficiency of WebGIS fully.
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