The Overview of GeoSemantic Web Service 榮峻德 台大地理所博士班學生

TOCs 1.1 Motivations 1. INTRODUCTION 1.2 Objectives 2.1 The semantic web 2. BACKGROUND AND RELATED WORKS 2.2 Ontology Nowadays / Data Warehouse 3. THE FRAMEWORK OF GEOSEMANTIC WEB SERVICE SDI / Web Services 2.3 Discover GIServices in SDI Semantic Web Services

1. INTRODUCTION

Motivation NCGIAUCGISInteroperability Cognitive Models of Geographic Space Computational Implementations of Geographic Concepts Geographies of the Information Society OGC 10 Challenges Cognition of Geo_ graphic Information Interoperability of Geographic Information The Future of the Spatial Information Infrastructure Three problems: Syntactic Structure Semantic GIServices: WFS WMS WCS WPS CS Cognition 、 Interoperability 、 GIServices

Motivation

Introduction 整合 GIS 資訊的年代 Interoperability Problem –Syntactic Data type, data format…etc. –Structure Projection, datum –Semantic Naming differences: same name but different concept. Concept differences: same concept but different names.

Introduction Applied Ontology into the architecture of SDI Build a GeoSemantic Web (service) Apply a Domain knowledge to prove the concept!

2. RELATED WORKS

Related Works Semantic Web –Semantic problems –What is semantic web? –Components of semantic web –Geospatial semantic web Ontologies –Ontology –The architecture of ontologies –Ontology languages –Geospatial ontologies Discover GIService on SDI –SDI (Spatial Data Infrastructure) –Web services –GIServices –Discover GIServices on SDI Domain Knowledge Reviews Semantic Web OntologySDI GIServices Domain Knowledge

Semantic Web

譬如：「台大裡的醉月湖」 Semantic Problems

Semantic Problems

Concept 2 “mont” “montaña” “mountain” “berg” Concept 1 “ ” Concept 3 Concept 4 Concept 5 Words in different languages Real world Mark, David （ 2005 ） Semantic Problems

Semantic Problems Brodeur et al., 2003

Semantic Problems Naming Heterogeneity: –Two data with the same data type and refer to the same domain concept, but have different names. Data Type Heterogeneity: –Two data with the same name and refer to the same domain concept, but represented with different data types. Conceptual Heterogeneity: –Two data with the same name and data type, but refer to different domain concepts.

Semantic Web What is Semantic Web ? –an extended web of machine-readable information and automated services that amplify the Web far beyond current capabilities

Semantic Web Components of Semantic Web

GeoSemantic Web UCGIS considered that the geospatial semantic web would be one of critical research priorities for geographic information science (Fonseca, 2002). The Geospatial Semantic Web is to capture, analyze and tailor geospatial information, much beyond the purely lexical and syntactic level which needs (Egenhofer, 2002): –Geospatial Ontology –Representation –match OGC (Open Geospatial Consortium): –GML (Geography Markup Language): xml-based –WFS (Web Feature Services), WMS (Web Map Services)…

Ontologies

Ontologies Ontology –Philosophy: the nature and the organization of reality. –Information Science: an explicit specification of a conceptualization. –Classes –relations

Ontologies

Ontologies Ontology languages –Ontology languages allow users to write explicit, formal conceptualizations of domain models which include following main requirements ： well-defined syntax formal semantics Convenience of expression and sufficient expressive power Efficient reasoning support –Class membership ： if x is an instance of a class C, and C is a subclass of D, then we can infer that x is an instance of D. –Equivalence of classes ： if A → B and B → C, then A → C. –Consistency ： if x is an instance of class A, and A is a subclass of B ∩ C, A is a subclass of D, and B and D are disjoint. –Classification ： if we have declared that certain property-value pairs are a sufficient condition for membership in a class A, then if an individual x satisfies such conditions, we can conclude that x must be an instance of A.

Ontologies Ontology languages –OWL (Web Ontology Language) specified by W3C = DARPA + OIL well-defined syntax formal semantics Convenience of expression and sufficient expressive power Efficient reasoning support OWL Software –Protégé ( –RACER (

Ontologies Geospatial Ontologies –Different spatial Cognition → Different spatial concept. Fonseca et al. （ 2002 ）

Ontologies Geospatial Ontologies – 認知空間中什麼樣的知識、 classes 、 relations

Ontologies The architecture of Ontologies

Discover GIService on SDI

Discover GIServices on SDI SDI –a multi-levelled, scalable, and adaptable collection of technical and human services, which are interconnected across system, organizational, and administrative boundaries via standardized interfaces. GIS for the Nation (2006)

Discover GIServices on SDI Web services –a networked application that is able to interact using standard application-to-application.

Discover GIServices on SDI GIService –network-based geographic information services that utilize both wired and wireless Internet to access geographic information, spatial analytical tools and other GIS resources. –GIS Data Access services & Geo-processing services OGC –WFS (Web Feature Service) –WMS (Web Map Service) –WPS (Web Processing Service) –CS (Catalogue Service)

Discover GIServices on SDI WMS example xd_Taipei

Discover GIServices on SDI –In previous literatures, there are two main parts used ontology applied into SDI: Discovering GIServices (Bernald et al., 2003; Bernard, Einspanier, Haubrock et al., 2003; Probst and Lutz, 2004; Klien, Lutz, and Kuhn, 2006; Lemmens, 2006; Lutz, 2006) Using ontology for semantic interoperability composes (Bernard, Einspanier, Lutz et al., 2003; Einspanier et al., 2003; Probst and Lutz, 2004; Lutz, 2006)

Discover GIServices on SDI Lutz, 2006

Domain Knowledge

Domain Knowledge Not decided yet. Scenario: Geomorphology – 溶洞（石灰岩洞、鐘乳石洞）：雨水或地下水溶解侵蝕石灰岩所形成的洞穴。 –Classes ：雨水、地下水、石灰岩、洞穴 –Relationships ：溶解侵蝕 地下水 石灰岩 溶解 侵蝕 GML Data GIS Data Index WFS Data WFS Data WFS shp GML Functions Analysis A Analysis B Analysis C

3. The framework of GeoSemantic Web Services

Conclusion The GeoSemantic web focuses on geospatial domain to extract explicitly geospatial knowledge that is used multi-level ontologies to manage. GeoSemantic interoperability will be the major research for users to discover GIS data or GIServices more accurate in SDI. In the future, a Geo-domain knowledge would be applied into the architecture of GeoSemantic web to evaluate the efficiency and accuracy.

Contact me : Calvin C. JUNG 榮峻德 Thank You ~ ! Questions ?