Name:             Jinsongdi Yu
Institute:         Jacobs University
Department:   Computer Science
Phone:            +49-(0)421-2003050
Email:             j.yu@jacobs-university.de

Geo raster web services provides access to a detailed and rich sets of geospatial information being used in a wide variety of earth system applications, such as in solar, atmosphere, oceans, cryosphere, solid earth, and biosphere research. However, the heterogeneity of services deployed in these disciplines tends to weaken interoperability of earth system science applications. To improve on this, the Open Geospatial Consortium (OGC) develops and maintains a family of open and interoperable geo service standards. To ensure interoperability of implementations which claim is to adhere to those standards, OGC has set up a conformance testing program with test suites for each OGC standard. Currently, this constitutes the most comprehensive conformance testing in the field of geo raster web services.
Currently, conformance testing for geo raster web services follows a specification-based black box approach. This approach organizes specification requirements as assertions and groups them by data retrieval and processing request and response functionality modules. However, there is no methodology to coherently classify these assertions; and tests based on this approach are neither comprehensive, nor can their completeness be proven. For example, correct geo coordinates and raster data values returned are not tested.
The goal of this thesis is to establish a methodology to formally derive tests and verification of geo raster web services from some pre-existing formal semantics definition of the service model. As our study example, we use the OGC WCPS standard which offers a suitably formalized language for imaging, signal processing, and statistics on multi-dimensional raster data. This provides a basis for a semantic-based conformance testing of geo raster web services. A formal geo scenarios testing approach will be developed and evaluated in real-life application scenarios. On the syntactic level, investigations will be carried out on validation approaches based on software engineering principles, such as testing, formal proof, and semi-formal approaches, and the recently published UML-B integrated methodology. Different approaches will be evaluated with respect to testing efficiency and coverage.
The expected outcome of this thesis is the improvement of geo raster web service interoperability using suitable syntax and semantic methodologies. Results will be fed into OGC for improving the existing test suites.
 
Start of doctoral thesis: 1.10.2008 | Defence: 11.01.2012

Supervisor: Prof. Dr. Peter Baumann (Jacobs University)
Co-supervisor: Prof. Dr. Peijun Du (China University of Mining and Technology)
                       Dr. Heinrich Stamerhohanns (Jacobs University)

Jinsongdi Yu, Peter Baumann: A Specification-Oriented Geospatial Coverage Ontology Study. Proc. ONTOSE, Hammamet, Tunisia, June 7 - 8, 2010

Jinsongdi Yu: Toward a Specification-based Quality Guarantee for Geo Raster Web Services: 70th OGC Technical Committee Meeting, Darmstadt, Germany. October 1st, 2009.

Jinsongdi Yu, Peter Baumann: A Specification-Oriented Geospatial Coverage Ontology Study. Proc. ONTOSE, Hammamet, Tunisia, June 7 - 8, 2010

CSC stipends from September 26th, 2008 until September 26th, 2011 for research stay at Jacobs University Bremen, Germany.