Abstract:In this paper, we proposed the PDFEMAP (PDF electronic map) that is a kind of new electronic map products aiming at the current situation and demand of the use of electronic map products. Firstly gives the definition and characteristics of PDFEMAP, followed by a detailed description of the data model and method for generating PDFEMAP, and finally expounds application modes of the PDFEMAP which feasibility and effectiveness are verified.

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Studies the regularity for changes of spatial relations based on the gradual changes of spatial location between two regional objects. Generates the conceptual neighborhood model of spatial relations like concentric circles, and provides the formal representation for them using graph theory. Based on the idea of "topylogy matters, metric refines" [1] , the model uses topological relations as basic classification and different direction and distance as the refinement of classification for spatial relations to reflect the levels of spatial relations. In addition, the changes of spatial relations between the conceptual neighborhoods are divided into six types. These changes are graded and evaluated according to the constraints degree of a variety of relations for spatial objects that in favor of formalization and computation. Finally, experiment is provided to illustrate that the conceptual neighborhood model and its formal description can describe the gradual changes of spatial relations between regional objects and compute the difference degree between spatial relations.

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