Annotated Services

A semantic annotation is a reference from some arbitrary structured (encoded in XML or XML-Schema) content, to a knowledge model which re-models the content’s model in another dialect and extends it with contextual information. More information about  semantic annotations in common and strategies developed and applied in ENVISION are available in D4.2 and at https://trac.assembla.com/sapience/wiki.

The following figure illustrates the, in ENVISION applied, annotation strategy schematically. Further details and a fine-grained description of the illustration are given in [1].

The Semantic Annotation Pattern. Meta-data describing external properties of a dataset are enriched with links pointing to service and data model vocabularies. A rule-based annotation approach aligns these vocabularies to domain ontologies.

To enhance Web services with semantics, two modeling approaches exist: top-down and bottom-up. The former has been adopted by OWL-S  and WSMO. It is assumed that service developers first model the semantics before grounding them into service descriptions such as WSDL. A wide range of legacy services using SOA technologies like WSDL and REST are already available. Annotating existing service descriptions in a bottom-up fashion is supported by SAWSDL. SAWSDL provides an extension attribute “modelReference”, which can be applied to various elements in a WSDL document and in XML Schema. This attribute points to a concept in an arbitrary ontology having the best semantic description of the underlying element. A recent notion for enabling semantic descriptions of existing Web services is WSMO-Lite. The Procedure-Oriented Service Model (POSM) is adopted from WSMO-Lite and will be used in this project. Developed by the Linked Open Services initiative, it fills the SAWSDL annotations with
semantic service descriptions. POSM builds on Web service descriptions in RDF, which in addition is suitable for the growing Linked Open Data (LOD) community. The service model contains generic statements of Web services, e.g. a service has an operation, which has input and output messages. POSM, similar to the WSDL description of a Web service, includes elements describing the operations, which are provided by the service. In WSDL descriptions an interface element is responsible for defining possible service operations exchanging messages defined in XML Schemas. In order to describe the semantics of the various parts, a “modelReference” attribute has to be added to the element which points to the counterpart in the service model.

In the following, we point to semantically annotated POSM descriptions corresponding to relevant Web services involved in the ENVISION use cases.

Landslide use case

The landslide use case description can be found at the following location:

The following services participate in the landslide use case scenario:

Oil spill use case

The oil spill use case description can be found at the following location:

The following services participate in the oil spill use case scenario:

Flood monitoring use case

The following services participate in the flood monitoring use case scenario:

Other available annotated services

The following additional semantically annotated services are currently available:

[1] Patrick Maué, Roth Marcell (2012) Lost in Translation – Mediating between distributed environmental resources. accepted at 6th International Congress on Environmental Modelling and Software (iEMSs) 1 – 5 July 2012, Leipzig, Germany

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