Riina Maigre

Compositional Logical Semantics for Business Process Languages

In this paper we propose a compositional logical semantics for business process languages to be used in automatic Web service composition. We introduce a concept of higher order work flow (HOWF) and use it for expressing control of business process. A precise semantics of HOWF enables us both to dynamically generate HOWF for automatic composition of services and to reason about the reachability of goals in process models when HOWF are described manually. Our semantics is general enough to cover different process languages; however, we mainly show its applicability in the context of OWLS and BPEL.

Handling Large Web Services Models in a Federated Governmental Information System

Experiments with large service models of a federated governmental information system are described. Large syntactic Web service models are being used for automatic composition of services in an e-government information system. A visual tool developed in software environment CoCoViLa has been used for handling syntactic service models and synthesis of compound services. For a given specification and a goal, the tool synthesizes a program that generates a service description in OWLS and BPEL.

Domain Ontology for Expressing Knowledge of Variants of Thermally Modified Wood Products

The thermally modified wood producer Thermory AS manufactures about 400 different products, which are ordered in large number of variants that makes the expression of the product variant knowledge and its validation very important. In this paper, we express knowledge of product variants as domain ontology in order to capture the product knowledge in the way that is consistent and shareable between humans and machines. Using Ontology Web Language (OWL) as Description Logics (DL) based ontology representation language enables to detect inconsistency in the product knowledge and customer order requirements. Constraints on valid product variants are expressed as OWL class expressions and as rules in Semantic Web Rule Language (SWRL). The provided knowledge representation method makes it possible to reduce combinatorial complexity of description of product variants and to place correct manufacturing orders saving time and money for the company.

Stratified Composition of Web Services

We propose an automatic service composition methodology where, three levels of composition knowledge are distinguished: user level, logical level and implementation level knowledge. We use a knowledge-based software development environment CoCoViLa that enables composition throughout these three levels. A motivation for this approach is a need to overcome the complexity of service composition on very large sets of atomic services we are dealing with in our application domain. The domain concerns federated governmental information systems.