guo qingsheng | Wuhan University (original) (raw)

Papers by guo qingsheng

Research paper thumbnail of On Geographic Spatial Relations and Reasoning in Automatic Map Design and Generalisation

Spatial relations have been investigated by cartographers, geographers, psychologists and compute... more Spatial relations have been investigated by cartographers, geographers, psychologists and computer scientists etc. The results coming out of this research build the base for the approach presented in this paper: The spatial relations are classified in local and global relations, which are important for spatial data handling in automatic map design and digitial generalisation. In this paper, cartographic label displacement and geometric cartographic line simplification which are based on spatial relations and spatial reasoning are analysed. In cartographic label displacement, the relations between cartographic features and their labels are mostly very complex; therefore a progressive method of spatial relation handling is used. For the purpose of an effective communication of geographic spatial information, the spatial knowledge in the graphic simplification process is also analysed.

Research paper thumbnail of Research on Equivalnce of Spatial Relations in Automatic Progressive Cartographic Generalization

Citeseer

In automatic cartographic generalization, the most important problem which must be resolved is to... more In automatic cartographic generalization, the most important problem which must be resolved is to keep the equivalence of spatial relations between spatial objects, these spatial relations are distance relation, directional relation, topological relations and so on. Among all these spatial relations, topological relation is considered as the relation that can reflect the best spatial information, so it should be the dominant relation. Because of this, it is important to keep the equivalence of topological relations in the progress of automatic progressive cartographic generalization. In this paper, the combinational reasoning method is used to represent topological relations, and the equivalence of topological relations in the process of cartographic generalization is discussed. Besides these, a method for topological relation abstraction is presented. Combining with some rules to deal with spatial relations in cartographic generalization, equivalence evaluation model of topological relations in spatial scene is established.

Research paper thumbnail of Computational complexity of spatial reasoning with directional relationship

Geo-spatial Information Science, 2002

The property of NP-completeness of topologic spatial reasoning problem has been proved. According... more The property of NP-completeness of topologic spatial reasoning problem has been proved. According to the similarity of uncertainty with topologic spatial reasoning, the problem of directional spatial reasoning should be also an NP-complete problem. The proof for the property of NP-completeness in directional spatial reasoning problem is based on two important transformations. After these transformations, a spatial configuration has been constructed based on directional constraints, and the property of NP-completeness in directional spatial reasoning has been proved with the help of the consistency of the constraints in the configuration.

Research paper thumbnail of Progressive graphic simplification of contours based on spatial reasoning

Geo-spatial Information Science, 2000

This paper discusses the rules representing relief with contour lines and methods for automatical... more This paper discusses the rules representing relief with contour lines and methods for automatically constructing relation of contour lines. Mean-while, the improvement of existent methods for extracting the topographic characteristic points and lines is described. On the basis of this analysis, we propose a series of practicable progressive graphic simplification ideas of contour lines and concrete algorithms for the exception’s handling. In this way, graphic generalizations of contour lines at different scales are integrated into one model that is convenient to implement, and in which contour lines’ intersection in generalization can be controlled.

Research paper thumbnail of The method of graphic simplification of area feature boundary with right angles

Geo-spatial Information Science, 2000

Some rules of simplification of area feature boundary and the method of acquiring spatial knowled... more Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of graphic simplification of area feature boundary with right angles based on its characteristics.

Research paper thumbnail of The spatial characteristics of a line and their application to line simplification

Geo-spatial Information Science, 2002

This paper discusses the spatial knowledge related to a line, and the characteristic points of li... more This paper discusses the spatial knowledge related to a line, and the characteristic points of lines is detected. According to the requirements of line generalization, new algorithms for identifying characteristic line points are presented. These characteristic points are used to improve the algorithms of line generalization. An algorithm for identifying bends is shown. In this paper, improved algorithms based on those by Douglas-Peucker, Visvalingam and Whyatt are shown. In this test, the progressive process of line generalization is emphasized.

Research paper thumbnail of A progressive line simplification algorithm

Geo-spatial Information Science, 2002

An application of line simplification considering spatial knowledge is described. A method for id... more An application of line simplification considering spatial knowledge is described. A method for identifying potential conflict regions, in order to avoid the self-intersection of generalized, lines, is also discussed. Further-more, a new progressive line simplification algorithm is presented. From the view point of spatial cognition, a spatial hierarchical structure is proposed, and its application to construction of spatial knowledge related to a line is explained.

Research paper thumbnail of VISUALIZING SCHEMATIC MAPS THROUGH GENERALIZATION BASED ON ADAPTIVE REGULAR SQUARE GRID MODEL

ABSTRACT Schematization is a quick visualization way to convey graphics information. In cartograp... more ABSTRACT Schematization is a quick visualization way to convey graphics information. In cartography, graphic schematization is one aspect of map generalization. This paper analyzes and summarizes the multiple criteria for schematic maps and quantifies these constraints functionally. Based on this, schematic map cartographic generalization framework based on the regular square grid is proposed. Furthermore, we research topological checking methods for schematic maps. Based on these constrains, an effective schematic map is schematized and visualized automatically in a test, while keeping the topological consistency of the network map between original and schematic map.

Research paper thumbnail of Construction of E-Government GIS Based on Net Platform and Web Service

ABSTRACT Based on the characters of the E-government GIS, the advantages of the E-government GIS ... more ABSTRACT Based on the characters of the E-government GIS, the advantages of the E-government GIS construction based on .Net and Web Service are analyzed. Based on this, the general framework of this system is designed, and a new model of publication prototype of spatial information is put forward , and the technical scheme about client, server and database are implemented. Finally, the application of the system is introduced.

Research paper thumbnail of On Geographic Spatial Relations and Reasoning in Automatic Map Design and Generalisation

Spatial relations have been investigated by cartographers, geographers, psychologists and compute... more Spatial relations have been investigated by cartographers, geographers, psychologists and computer scientists etc. The results coming out of this research build the base for the approach presented in this paper: The spatial relations are classified in local and global relations, which are important for spatial data handling in automatic map design and digitial generalisation. In this paper, cartographic label displacement and geometric cartographic line simplification which are based on spatial relations and spatial reasoning are analysed. In cartographic label displacement, the relations between cartographic features and their labels are mostly very complex; therefore a progressive method of spatial relation handling is used. For the purpose of an effective communication of geographic spatial information, the spatial knowledge in the graphic simplification process is also analysed.

Research paper thumbnail of Research on Equivalnce of Spatial Relations in Automatic Progressive Cartographic Generalization

Citeseer

In automatic cartographic generalization, the most important problem which must be resolved is to... more In automatic cartographic generalization, the most important problem which must be resolved is to keep the equivalence of spatial relations between spatial objects, these spatial relations are distance relation, directional relation, topological relations and so on. Among all these spatial relations, topological relation is considered as the relation that can reflect the best spatial information, so it should be the dominant relation. Because of this, it is important to keep the equivalence of topological relations in the progress of automatic progressive cartographic generalization. In this paper, the combinational reasoning method is used to represent topological relations, and the equivalence of topological relations in the process of cartographic generalization is discussed. Besides these, a method for topological relation abstraction is presented. Combining with some rules to deal with spatial relations in cartographic generalization, equivalence evaluation model of topological relations in spatial scene is established.

Research paper thumbnail of Computational complexity of spatial reasoning with directional relationship

Geo-spatial Information Science, 2002

The property of NP-completeness of topologic spatial reasoning problem has been proved. According... more The property of NP-completeness of topologic spatial reasoning problem has been proved. According to the similarity of uncertainty with topologic spatial reasoning, the problem of directional spatial reasoning should be also an NP-complete problem. The proof for the property of NP-completeness in directional spatial reasoning problem is based on two important transformations. After these transformations, a spatial configuration has been constructed based on directional constraints, and the property of NP-completeness in directional spatial reasoning has been proved with the help of the consistency of the constraints in the configuration.

Research paper thumbnail of Progressive graphic simplification of contours based on spatial reasoning

Geo-spatial Information Science, 2000

This paper discusses the rules representing relief with contour lines and methods for automatical... more This paper discusses the rules representing relief with contour lines and methods for automatically constructing relation of contour lines. Mean-while, the improvement of existent methods for extracting the topographic characteristic points and lines is described. On the basis of this analysis, we propose a series of practicable progressive graphic simplification ideas of contour lines and concrete algorithms for the exception’s handling. In this way, graphic generalizations of contour lines at different scales are integrated into one model that is convenient to implement, and in which contour lines’ intersection in generalization can be controlled.

Research paper thumbnail of The method of graphic simplification of area feature boundary with right angles

Geo-spatial Information Science, 2000

Some rules of simplification of area feature boundary and the method of acquiring spatial knowled... more Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of graphic simplification of area feature boundary with right angles based on its characteristics.

Research paper thumbnail of The spatial characteristics of a line and their application to line simplification

Geo-spatial Information Science, 2002

This paper discusses the spatial knowledge related to a line, and the characteristic points of li... more This paper discusses the spatial knowledge related to a line, and the characteristic points of lines is detected. According to the requirements of line generalization, new algorithms for identifying characteristic line points are presented. These characteristic points are used to improve the algorithms of line generalization. An algorithm for identifying bends is shown. In this paper, improved algorithms based on those by Douglas-Peucker, Visvalingam and Whyatt are shown. In this test, the progressive process of line generalization is emphasized.

Research paper thumbnail of A progressive line simplification algorithm

Geo-spatial Information Science, 2002

An application of line simplification considering spatial knowledge is described. A method for id... more An application of line simplification considering spatial knowledge is described. A method for identifying potential conflict regions, in order to avoid the self-intersection of generalized, lines, is also discussed. Further-more, a new progressive line simplification algorithm is presented. From the view point of spatial cognition, a spatial hierarchical structure is proposed, and its application to construction of spatial knowledge related to a line is explained.

Research paper thumbnail of VISUALIZING SCHEMATIC MAPS THROUGH GENERALIZATION BASED ON ADAPTIVE REGULAR SQUARE GRID MODEL

ABSTRACT Schematization is a quick visualization way to convey graphics information. In cartograp... more ABSTRACT Schematization is a quick visualization way to convey graphics information. In cartography, graphic schematization is one aspect of map generalization. This paper analyzes and summarizes the multiple criteria for schematic maps and quantifies these constraints functionally. Based on this, schematic map cartographic generalization framework based on the regular square grid is proposed. Furthermore, we research topological checking methods for schematic maps. Based on these constrains, an effective schematic map is schematized and visualized automatically in a test, while keeping the topological consistency of the network map between original and schematic map.

Research paper thumbnail of Construction of E-Government GIS Based on Net Platform and Web Service

ABSTRACT Based on the characters of the E-government GIS, the advantages of the E-government GIS ... more ABSTRACT Based on the characters of the E-government GIS, the advantages of the E-government GIS construction based on .Net and Web Service are analyzed. Based on this, the general framework of this system is designed, and a new model of publication prototype of spatial information is put forward , and the technical scheme about client, server and database are implemented. Finally, the application of the system is introduced.