Stanislav Pokraev

Context-Aware Recommendations in the Mobile Tourist Application COMPASS

This paper describes the context-aware mobile tourist application COMPASS that adapts its services to the user’s needs based on both the user’s interests and his current context. In order to provide context-aware recommendations, a recommender system has been integrated with a context-aware application platform. We describe how this integration has been accomplished and how users feel about such an adaptive tourist application.

COSMO: A conceptual framework for service modelling and refinement

This paper presents a conceptual framework for service modelling and refinement, called the COSMO (COnceptual Service MOdelling) framework. This framework provides concepts to model and reason about services, and to support operations, such as composition and discovery, which are performed on them at design and run-time. In particular, the framework should facilitate the use of different service description languages tailored to different service aspects, such as the behaviour of a service and the information it manipulates, or design tasks, such as modelling, analysis and implementation. The idea is that models produced by these languages can be mapped onto the concepts of the framework, thereby facilitating one to relate these models, e.g., to verify consistency. Therefore, a requirement on the framework is to provide concepts that capture all elementary and generic service properties that are relevant during the service development process. We capture these properties by analysing existing service definitions and from earlier experience. Furthermore, we want the same concepts to be applicable throughout the service development process when modelling and refining services at successive abstraction levels. The framework distinguishes three generic abstraction levels, and describes an approach to assess the conformance between the service models produced at these abstraction levels.

Finding the story: broader applicability of semantics and discourse for hypermedia generation

Generating hypermedia presentations requires processing constituent material into coherent, unified presentations. One large challenge is creating a generic process for producing hypermedia presentations from the semantics of potentially unfamiliar domains. The resulting presentations must both respect the underlying semantics and appear as coherent, plausible and, if possible, pleasant to the user. Among the related unsolved problems is the inclusion of discourse knowledge in the generation process. One potential approach is generating a discourse structure derived from generic processing of the underlying domain semantics, transforming this to a structured progression and then using this to steer the choice of hypermedia communicative devices used to convey the actual information in the resulting presentation.This paper presents the results of the first phase of the Topia project, which explored this approach. These results include an architecture for this more domain-independent processing of semantics and discourse into hypermedia presentations. We demonstrate this architecture with an implementation using Web standards and freely available technologies.

Preparing SCORM for the semantic Web

In this paper we argue that the effort within the context of Semantic Web research, such as RDF and DAML-S. will allow for better knowledge representation and engineering of educational systems and easier integration of e-learning with other business processes. We also argue that existing educational standards, such as SCORM and LOM could be mapped to those technologies, providing for more efficient automation of processes like educational resource annotation, and intelligent accessibility management. In this way we can use a successful combination of the technical advances outside of educational context and the existing educational standards, and allow for easier interoperability. To illustrate these issues and a solution approach we present the OntoAIMS educational environment.

Construction of negotiation protocols for e-commerce applications

A company doing e-business needs capabilities to negotiate electronically the parameters of its deals in order to fully utilize the potential of the Information and Communication technology (ICT). This paper focuses on construction of negotiation protocols for e-commerce with the following properties: (a) formal semantics, (b) compositionally constructed, and (c) dynamically reconfigurable. We apply the Reo coordination language to demonstrate that one can specify and implement negotiation protocols possessing the desired properties.

Semantic Service Modeling - Enabling System Interoperability

Interoperability is the capability of different systems to use each other’s services effectively. It is about sharing functionality and information between systems at different levels, e.g., between physical devices, software applications, business units within one organization, or between different organizations. Interoperability implies that systems are able to interact (i.e., exchange messages), read and understand each other’s messages, and share the same expectations about the effect of the message exchange. In this paper we analyze and define in detail what it means for software systems to be interoperable. We identify three different levels of interoperability – the syntactic, semantic and pragmatic level – and define the requirements for assessing interoperability at each of these levels. We propose a method for formally verifying the semantic and pragmatic interoperability of a number of systems, given a target for integration.

A Method for Formal Verification of Service Interoperability

Service interoperability is a major obstacle in realizing the SOA vision. Interoperability is the capability of multiple, autonomous and heterogeneous systems to use each others services effectively. It is about the meaningful sharing of functionality and information that leads to the achievement of a common goal. In this paper we identify requirements for semantic and pragmatic interoperability. We further propose a method for assessing whether a composite system meets these requirements

Model-driven development of mediation for business services using COSMO

Although service-oriented architectures offer real benefits when pursuing business integration and flexibility, there are still no satisfactory solutions to accomplish co-operation between services of existing systems that have no perfect match. In the case of incompatible services, a Mediator may be introduced which resolves semantic and syntactic interoperability problems by intervening in the co-operation between systems. Building Mediators is currently often a manual process, resulting in dedicated IT-driven solutions, with no concern for re-use of process, models or code. This paper presents a framework to guide the development of Mediators, with the following objectives: (i) uncover and capture the actual interoperability problem that needs to be solved; (ii) allow the involvement of non-IT (i.e. business) experts in the development of the solution; (iii) support evolution of the solution and re-use of results in case of changing interoperability requirements; (iv) facilitate automation of parts of the process. The framework is based on service-oriented and model-driven techniques. Available tool support for the different elements in the framework is indicated.

Business Level Service-Oriented Enterprise Application Integration

In this paper we propose a new approach for service-oriented enterprise application integration (EAI). Unlike current EAI solutions, which mainly focus on technological aspects, our approach allows business domain experts to get more involved in the integration process. First, we provide a technique for modeling application services at a sufficiently high level of abstraction for business experts to work with. Next, these business experts can model the orchestration as well as the information mappings that are required to achieve their integration goals. Our mediation framework then takes over and realizes the integration solution by transforming these models to existing service orchestration technology.

Requirements for secure logging of decentralized cross-organizational workflow executions

The control of actions performed by parties involved in a decentralized cross-organizational workflow is done by several independent workflow engines. Due to the lack of a centralized coordination control, an auditing is required which supports a reliable and secure detection of malicious actions performed by these parties. In this paper we identify several issues which have to be resolved for such a secure logging system. Further, security requirements for a decentralized data store are investigated and evaluated with regard to decentralized data stores.