Research Of Model And Methods Based On Ontology For Geo-information Semantic Transformation

The paper leads the ontology thoughts, the methodology and language semantics viewpoint into the geographic information science domain, elucidates the exact character and meaning of geographic ontology and the function and the sense of ontology in the geographic information science domain, analyses the mechanism that language expresses semantics and the relation between the language and the ontology. The paper deeply discusses the geographic information semantic conversion theory problem based on the ontology, combines language analysis with ontology building to realize the semantic conversion in different language forms, and designs the semantic conversion model. The paper analysis geographic domain ontology, suggests the principle and method for building domain ontology, thoroughly analysis domain ontology manipulation which contains ontology cutting and semantic similarity degree computing, and establishes the foundation for the semantic conversion. The paper does an experiment on GIS data transformation between GIS data ontology metamodeling and metamodeling based on MDA metamodeling framework and mechanism, explores geographic information semantic conversion under structural linguistics. The paper distills geographic knowledge with the ontology annotation and natural language management technology in natural language, realizes the experiment on the conversion from non-structural spatial information description to structural geographic ontology.The main works of the paper is as follow:1. This paper thoroughly discusses the mechanism semantic expression of language, compares the relations between language and ontology, indicates the relation between language semantic and ontology theory method, analysis the connection in different description language, this offer theory base for using ontology technology to realize the conversion of geographic information.2. This paper puts forward geographic information semantic conversion model based on ontology. It analysis the characteristics of geographic information, compares typical languages of describing geographic information, explores the methods of geographic information based on ontology, indicates the principles and steps for establishing geographic information domain ontology. This paper uses some sources such as thesauri, topographic map, geographic information classify vocabulary, some methods such as ontology cutting, to establish geographic information domain ontology. This paper launches on languages of describing geographic information, breaks up forms and semantics of language, establishes geographic information semantic conversion model based on ontology by high-low order model theory. The paper discusses conversion flow and pattern based on this model.3. This paper does an experiment on GIS data transformation based on ontology metamodeling. The paper compares modeling in software engineering with metamodeling technology and ontology, abstract ontology level and element model are corresponding, puts forward GIS data transformation methods based on ontology metamodeling. The paper analysis and establishes GIS data element model by MDA and UML extended mechanism, modeling GIS data with element model. The paper constitutes GIS data conversion flow by using geographic information semantic conversion model based on ontology, does related experiment on GIS data conversion.4. This paper establishes experimental platform for ontology similarity calculation. Through analyzing existing semantic similarity algorithm and ontology mapping prototype system, indicates that it should use different algorithm or algorithm combinatorial according as different tasks. The paper designs and realizes the experiment based on geographic information semantic similarity algorithm, makes it as the platform for algorithm analysis and evaluation. The paper realizes some semantic similarity algorithm such as MDSM algorithm, semantic distance algorithm based on HowNet dictionary and altered SF algorithm. In experiment platform, the paper tests capability of these algorithm with related cases, evaluates the influence to similarity algorithm of ontology cutting.5. This paper researches the problem for dealing with non-structural spatial information. Getting geographic cognition from non-structural spatial description, transforming formal geography knowledge into customary natural language form, all of this is important pattern for conversion geographic information. The paper analysis existing methods of natural language processing and knowledge extraction, discusses its application situation in geographic information domain. The paper puts forward the technology approach combining ontology annotation and natural language processing, extracts geography knowledge from geographic information description of natural language form, then accomplishes the conversion from non-structural geographic information to structural geographic ontology. The paper designs a system which supports multi-ontology semantic annotation, describes the formal geographic ontology which is extracted from HowNet. The paper analysis some key technologies such as improving the word segmentation results with domain ontology, creating phrase structure by compounding conception, describing rules with domain syntactical patter. The paper tests related algorithms and rules in experimental system.