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Presentation. A geo-ontology to support the semantic integration of geoinformation from the National Spatial Data Infrastructure Authors : Paulo J. A. Gimenez, Mastering Asterio Kiyoshi Tanaka, DSc Fernanda Baião, DSc. Contextualization.
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Presentation A geo-ontology to support the semantic integration of geoinformation from the National Spatial Data Infrastructure Authors: Paulo J. A. Gimenez, Mastering Asterio Kiyoshi Tanaka, DSc Fernanda Baião, DSc
Contextualization • Increasingly demand for the availability of integrated geoinformation: • The profusion of geoinformation. • The diversity of providers. • Over 30 years of evolution and growth of the geospatial content. • The National Spatial Data Infrastructure (INDE) : • To provide an effective and efficient access and availability of spatial data. • Governments and public entities engaged. • Web 2.0 technologies: • Mature and available. • The necessity for formalization, representation and integration of the geoinformation at the semantic level: still open !!! [Diaz ET AL 2012]
The Challenge of Geo-Semantic • Interoperability (by SDI dimension) andIntegration (by Data dimension). • Main Levels of Interoperability • Syntactic: how geographic objects will move amonginstitutions and these to society? • Approaches from ISO, OGC and OASIS patterns and directives. • Semantic: the choice of an ontology or use of semantic resources to describe geographic objects and their interrelationships. • Main Geospatial heterogeneity issues • Geospatiality: features and geometries of features; geographic and non-geographic relationships; systems and coordinate; scales conflicts; • Geo-semantics: discernment of a feature; spatial reasoning and representation dissonance.
Goal of this proposal • Present an approach to the creation of a geo-ontology for representinggeographic objects within the context of NSDI (INDE) from the associated standards enabling the discoveryand integration of geoinformation.
The Brazilian Context: “INDE” • The NSDI (INDE) • Arrange of SDI in different levels and providers. • Cartographic and basic geoinformation structured by ET-EDGV standard. • Follows e-PING architecture, references the OGC standards and adds owned standards: • MGB Profile (Brazilian Geographic Metadata Profile), based on ISO 19115:2003. • ET-EDGV (Technical Specification for Geographic Vector Data Structure). [CONCAR 2010]
Geo-ontology basic concepts • Geo-ontology = {C, R, A, X, I}, where: • C (concepts) represents concept set of geographic object; • R (relations) is a relation set and it mainly describes relation set among concepts; • A (attribute) shows attribute’s set of geographic objects; • X (axioms) is a lot of axioms and it is a constraint rules among the concepts, relation and attribute; • I (instances) is a set of definition about instances. [Wang, Li and Song 2008]
Methodological approach used • Combining existing methodologies from the literature: • The Simple Knowledge-Engineering Methodology [Noy and McGuinness 2001]. • Simplicity and efficiency. • Uses a set of competency questions (CQ) to determine the scope of the ontology. • The approach of Wang ET AL [Wang, Li and Song 2008] • Uses the "Concept lattice“: • Sets of objects and attributes from geographic concepts that represent the main aspects of the geospatial domain: is-a, kind-of, part-whole, dependency, instantiation and member relationships, as well as the relationship between attributes and concepts. • The work from Bishr [Bishr 2008] • Specifically addresses the geographical domain. • Establishes the elements that must be observed during the construction of the geo-ontology concepts.
Methodological approach used • Following the steps and directives:
The geo-ontology of INDE • Reuse and reference to known models of the geographical
Ontology for Geographical Names • The Geographic name or toponym standard allows the identification of a Geographic Feature or Accident. • The toponymic phrase consists of two parts: • Generic term: the element on the geographical entity that receives the name. • Specific term: the element that distinguishes the identity of the geographic element. • [IBGE 2010, Lima 2011 apud Dick 1990] • The proposed ontology brings: • Correlation between term and toponyms. • Lists of generic terms (as proposed in [IBGE 2010]). • Support for names denoting variation in gender (male x female) and number (plural x singular). • Alternative toponymic phrases for a particular geographical area. • Support for geographical names composed of multiple toponymic phrases.
Ontology for Brazilian Geographic Metadata Profile • Ontologies for geographic metadata add semantic meaning and relationship to describe the underlying data.[Di and Zhao 2008] • The proposed ontology describes: • The basic characteristics for the representation of concepts defined in the MGB Profile and related to the “ISO 19115” ontology. • Sections and entities: as ontology classes. • Information and elements: as properties of classes or enumerated lists. • Same information elements shared among several sections with distinct terminology: as synonym relationships. • Cardinality restrictions mapped according to:
Ontology for Brazilian Geographic Domain • Based on the characteristics of geographic objects, spatial relationships and spatial primitives described in ET-EDGV. • The guidelines for the construction of each element and concept defined in ET-ADGV. • The proposal ontology describes: • Classes and Relationship evaluated at the semantic level: as concepts based on class definitions and subtypes described. • Hierarchical classification of concepts: as the categories of ET-EDGV and classifications of geo-concepts proposed by Wang[Wang, Li and Song 2008]. • The conceptual connection with the MGB Profile ontology. • Cardinality restrictions and Conditionality relations mapped according to:
Ontology for Brazilian Geographic Domain *Partial sub-ontology 16
The Competency Questions validation • CQ1: Which conditions or characteristics are required by a Geographic name so that it addresses (identifies) a Geographic Feature? • CQ2: Which conditions or characteristics are required by a Geographic Metadata so that it can be associated to a Geographic Name when identifying Geographic Feature? • CQ3: How are the needs for cartographic generalization of geographic features be identified? • CQ4: How can we identify the same object being represented as distinct cartographic features using different scales?
Application of geo-ontology proposed • The proposed geo-ontology must be considered to: • Integration of the associated metadata. • Correlation with the geographical names. • The alignment with the ontology that describes the INDE geo-services. • The example scenario considers: • Integrated geoinformation is obtained from the basic geoinformation available in INDE. • Implementation of geo-processing to compose the integrated geo-information with its resulting metadata.
Related Works • Some studies have been made to define and specify the possible structuring of geo-ontologies sets to represent geographic space: [Bishr 2008],[Kun, Wang and Shuang-Yun 2005]and especially • Di and Zhao [Di and Zhao 2008] defines several levels of abstraction for geo-ontologies • Wang's approach [Wang, Li and Song 2008] uses the "Concept lattice" 19
Final Considerations • The main contribution of this proposal: • The proposed geo-ontology • The combination of concepts from the geographic names, metadata and geographic entities, providing support for analysis, applications and multifaceted uses. • Secondary effects: • Intention to (re)open the discussion and the application prospect to maximize the use of basic geoinformation available in INDE. • This work is essential part of study about semantic integration of several heterogeneous sources in the Brazilian context. • Much has to be done yet, to achieve a geo-ontology that can be accepted as the basis for this main study. 20
Final Considerations • Some future work in order to mature the geo-ontology proposed: • Extension to • cover the needs of Systematic Cadastral Mapping as soon as the ET-EDGV specifies them; • represent metadata of geo-services that are not yet covered by the MGB Profile and adaptation of coded values lists to reflect the national context; • geo-field in alignment to ET-PCDG under elaboration; • Creation of geographic quality control ontology for validation and verification of geospatial data quality for alignment with the future ET-CQPCDG specification; • Expansion of • Brazilian Geographic Domain Ontology to match ET-EDGV specification in a complete way, considering all rules and orientations in there; • Brazilian Geographic Names Ontology to treat the concepts associated with historical, ethnological and linguistic characteristics of toponyms. • Implementation of a framework for semantic integration of spatial data from INDE using this proposed geo-ontology: under development. 21
Congratulations ? A geo-ontology to support the semantic integration of geoinformation from the National Spatial Data Infrastructure paulo.gimenez@uniriotec.br tanaka@uniriotec.br fernanda.baiao@uniriotec.br