Abstract
Semantic Web Services (SWS) has been an active research topic in the recent years. It aims to
achieve automatic Web service discovery, and invocation and composition of services, by adding
semantics to the services, which is very significant for accelerating the achievement of Serviceoriented
architectures by solving a lot of interoperability issues. Geospatial data on the Web
contains more and more important information. Capturing, analyzing and managing such data can
help people to achieve various kinds of tasks. Discovery of Semantic Web Services in Geospatial
domain is therefore significant. Nowadays the existing semantic Web service discovery frameworks
in geospatial domain have either complex interface or require extra knowledge (for instance, the
Web Service Modeling Language (WSML) to be able to provide correct queries.
This thesis suggests an Ontology Based Natural Language Discovery of Semantic Web Services
(ONALDIS). ONALDIS works generally in the geospatial domain, and offers a command line
interface which takes natural language questions as input, and gives a WSML query as output. This
WSML query can be further processed by an existing SWS discovery framework to discover
semantic Web services. ONALDIS achieves the mapping between natural language query and
WSML query by analyzing domain ontologies with some rules and generates word sets and WSML
queries from the ontologies.
In this thesis, semantic Web services and geospatial domain are first introduced. The SWING
system and the need for a natural language interface are then discussed. Some existing approaches
for natural language interfaces, mainly Question Answering (QA) systems are presented. Further,
ONALDIS is introduced as a solution of a natural language interface for semantic Web service
discovery in the geospatial domain, with an implementation for the SWING system. Finally, the
conclusions are presented and further work is suggested.