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Digital watermark technology of GIS vector data consists of designing the digital watermark algorithm and evaluating the digital watermark algorithm performance, also, robustness is a most important evaluation indicator of the digital watermark algorithm performance, therefore, this article focuses on evaluating the robustness of digital watermark algorithm of GIS vector data.
Topological relations are research focus in 3D GIS. Constructing nodes and arcs from curves, building the topological relations of these primitives with their parent geometry and other geometries, and forming the topological graph, are the basis of the calculation of topological relationship. The formal description and smallest set of topological relationships of 3D curves are given. The line segments...
A hybrid 3D spatial data structure for the integration of aboveground, ground and underground objects based on spatial cognition theory is proposed, which considers the space subdivision and topology completeness. Object-oriented method is used to abstract objects in real world which is defined into three levels. Geometry primitives and topology primitives are defined in this data structure. Topology...
Featured in bad robustness, the single watermarking algorithm of GIS vector data can't meet people's need in some aspects. Yet, the multiple watermarking can embed several watermarks in the host in one way or several ways, making up the disadvantages of the traditional watermarking to some degree. However, many multiple watermarking studies are focused on the multimedia, and fewer on GIS vector data...
To address the issues of family tree information sharing, mining and spatial-temporal analyzing, this paper introduces database, network and GIS technologies into the research of family tree. It studies the mode of family tree standardization, digitization, spatialization and networking, and discusses the theory foundation, implementing techniques, cooperation platform of family tree information sharing...
Functional structure and framework of a universal GML schema-based parser, along with design and implementation of the integrative grammatical and semantic database (abbreviated to IGSD) that is the core component of GML parser, have been discussed in this paper. IGSD lays the foundation for GML grammar validation and universal parsing of GML data. Whereas universal GML parser based on IGSD would...
Numerous geographical models distributed in different geographical locations or cyberspaces lead to difficulties for sophisticated geographical problems solving due to the heterogeneity and decentralization. Grid computer technology provides a new way to solve problems in geographical sharing and service based on geospatial information technology. The method for understanding, describing and representing...
Currently OGC GML (Geography Markup Language) specification has been the in fact standard of GIS data sharing and exchanging, and spatial interoperation. Adopting nested association expression approach of XML data, GML data documents store both spatial information and semantic relationship information of geographical elements. In order to improve the efficient of path query on GML two type information,...
At present, GML data compression is a hotspot in the fields of geographic information sharing, interoperability. Based on the analysis of characteristics of traditional GML data compression methods, the paper proposed a GML compressor with holistic isomorphic characteristics, which achieves semantic isomorphic compression by constructing index encodings of feature elementspsila tags and achieves spatial...
Based on its characteristics of quickness, portability and friendly interaction interface, mobile GIS for spatial data collection has become an important developing direction of GIS as well as a major method for GIS data collection. However, the current mobile GIS data collection studies mainly focus on the implementation of mobile calculation but overlook the integrative mechanism for mobile data...
As the deeply and broadly applying GIS, GIS has turned into the main technology of management of spatial information as well as integrated platform carried with spatial information, and gradually melted into mainstream of IT. However, due to the content and source diversity of spatial data and the platform difference of GIS software, GIS application is still a "black box" which leads to...
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