随着电脑软硬件技术的进步,地理信息系统CIS,这个对国内许多管理者来说尚属陌生的名字,正在从高校和国家科研机构的实验室走向现代经济管理和社会管理的方方面面。 GIS是地理信息系统Geo- graphical Information System的英文缩写,简...随着电脑软硬件技术的进步,地理信息系统CIS,这个对国内许多管理者来说尚属陌生的名字,正在从高校和国家科研机构的实验室走向现代经济管理和社会管理的方方面面。 GIS是地理信息系统Geo- graphical Information System的英文缩写,简单地说,GIS是利用计算机来管理空间资料与非空间资料的系统。所谓空间资料,是指存在地表附近的各项地征资料,例如火车站、市政府、公路、桥梁、河流、湖泊、行政区域等地表附近的点、线、面资料。而非空间资料（又称属性资料）则为与这些地征相关的属性。展开更多
With the construction of spatial data infi＇astructure, automated topographic map generalization becomes an indispensable component in the community of cartography and geographic information science. This paper descri...With the construction of spatial data infi＇astructure, automated topographic map generalization becomes an indispensable component in the community of cartography and geographic information science. This paper describes a topographic map generalization system recently developed by the authors. The system has the following characteristics： 1） taking advantage of three levels of automation, i.e. fully automated generalization, batch generalization, and interactive generalization, to undertake two types of processes, i.e. intelligent inference process and repetitive operation process in generalization; 2） making use of two kinds of sources for generalizing rule library, i.e. written specifications and cartographers＇ experiences, to define a six-element structure to describe the rules; 3） employing a hierarchical structure for map databases, logically and physically; 4） employing a grid indexing technique and undo/redo operation to improve database retrieval and object generalization efficiency. Two examples of topographic map generalization are given to demonstrate the system. It reveals that the system works well. In fact, this system has been used for a number of projects and it has been found that a great improvement in efficiency compared with traditional map general- ization process can be achieved.展开更多
文摘随着电脑软硬件技术的进步,地理信息系统CIS,这个对国内许多管理者来说尚属陌生的名字,正在从高校和国家科研机构的实验室走向现代经济管理和社会管理的方方面面。 GIS是地理信息系统Geo- graphical Information System的英文缩写,简单地说,GIS是利用计算机来管理空间资料与非空间资料的系统。所谓空间资料,是指存在地表附近的各项地征资料,例如火车站、市政府、公路、桥梁、河流、湖泊、行政区域等地表附近的点、线、面资料。而非空间资料（又称属性资料）则为与这些地征相关的属性。
基金Under the auspices of the National Natural Science Foundation of China (No. 40301037), and a PolyU Project(G-T873)
文摘With the construction of spatial data infi＇astructure, automated topographic map generalization becomes an indispensable component in the community of cartography and geographic information science. This paper describes a topographic map generalization system recently developed by the authors. The system has the following characteristics： 1） taking advantage of three levels of automation, i.e. fully automated generalization, batch generalization, and interactive generalization, to undertake two types of processes, i.e. intelligent inference process and repetitive operation process in generalization; 2） making use of two kinds of sources for generalizing rule library, i.e. written specifications and cartographers＇ experiences, to define a six-element structure to describe the rules; 3） employing a hierarchical structure for map databases, logically and physically; 4） employing a grid indexing technique and undo/redo operation to improve database retrieval and object generalization efficiency. Two examples of topographic map generalization are given to demonstrate the system. It reveals that the system works well. In fact, this system has been used for a number of projects and it has been found that a great improvement in efficiency compared with traditional map general- ization process can be achieved.
