Ourania Hatzi

An Integrated Approach to Automated Semantic Web Service Composition through Planning

The paper presents an integrated approach for automated semantic web service composition using AI planning techniques. An important advantage of this approach is that the composition process, as well as the discovery of the atomic services that take part in the composition, are significantly facilitated by the incorporation of semantic information. OWL-S web service descriptions are transformed into a planning problem described in a standardized fashion using PDDL, while semantic information is used for the enhancement of the composition process as well as for approximating the optimal composite service when exact solutions are not found. Solving, visualization, manipulation, and evaluation of the produced composite services are accomplished, while, unlike other systems, independence from specific planners is maintained. Implementation was performed through the development and integration of two software systems, namely PORSCE II and VLEPPO. PORSCE II is responsible for the transformation process, semantic enhancement, and management of the results. VLEPPO is a general-purpose planning system used to automatically acquire solutions for the problem by invoking external planners. A case study is also presented to demonstrate the functionality, performance, and potential of the approach.

The PORSCE II Framework: Using AI Planning for Automated Semantic Web Service Composition

This paper presents PORSCE II, an integrated system that performs automatic semantic web service composition exploiting AI techniques, specifically planni ng. Essential steps in achieving web service composition include the translation of the web service composition problem into a solver-ready planning domain and problem, followed by the acquisition of solutions, and the translation of the solutions back to web service terms. The solutions to the problem, that is, the descriptions of the desired composite service, are obtained by means of external domain-independent planning systems, they are visualized and finally evaluated. Throughout the entire process, the system exploits semantic information extracted from the semantic descriptions of the available web services and the corresponding ontologies, in order to perform composition under semantic awareness and relaxation.

A Specialized Search Engine for Web Service Discovery

Web service discovery on the web is not a trivial task as the number of available web service descriptions continuously increases, and global UDDI registries are no longer available. As discovery through conventional, general-purpose search engines does not yield satisfactory results, a more promising alternative should be explored through specialized search engines. This paper explores the design and implementation of such a framework, resulting in WESS, a search engine targeted to discovering and retrieving web service descriptions. The presented system features an adaptive web service description collection process, through specialized and directed crawling, as well as an enhanced indexing and retrieval mechanism, which handles description documents as semi-structured text, separating actual information from tags and annotations. The paper also presents experiments and use cases regarding different search scenarios, in addition to performance results.

Semantic awareness in automated web service composition through planning

PORSCE II is a framework that performs automatic web service composition by transforming the composition problem into AI planning terms and utilizing external planners to obtain solutions A distinctive feature of the system is that throughout the entire process, it achieves semantic awareness by exploiting semantic information extracted from the OWL-S descriptions of the available atomic web services and the corresponding ontologies This information is then used in order to enhance the planning domain and problem Semantic awareness facilitates approximations when searching for suitable atomic services, as well as modification of the produced composite service The alternatives for modification include the replacement of a certain atomic service that takes part in the composite service by an equivalent or a semantically relevant service, the replacement of an atomic service through planning, or the replanning from a certain point in the composite service The system also provides semantic representation of the produced composite service.

Semantic Web Service Composition Using Planning and Ontology Concept Relevance

This paper presents PORSCE II, a system that combines planning and ontology concept relevance for automatically composing semantic web services. The presented approach includes transformation of the web service composition problem into a planning problem, enhancement with semantic awareness and relaxation and solution through external planners. The produced plans are visualized and their accuracy is assessed.

A visual programming system for automated problem solving

Although new AI planning algorithms and techniques are being developed and improved rapidly, there is a lack of efficient and easy to use systems able to incorporate and utilize them. Furthermore, while visual representation facilitates design, maintenance and comprehension of planning domains and problems, very few systems incorporate it. This paper presents VLEPPO, an integrated system aiming at visually modeling planning domains and problems through a convenient graphical interface, while maintaining compatibility with the Planning Domain Definition Language (PDDL), with import and export features. Solutions to planning problems can be obtained by invoking different planners employing the web services technology. The demonstration of the system is performed through a case study involving web service composition viewed as a planning problem.

A Synergy of Planning and Ontology Concept Ranking for Semantic Web Service Composition

This paper presents a prototype system that exploits planning and an ontology concept ranking algorithm for composing semantic Web services (PORSCE). The system exploits the inferencing capabilities of a Description Logics Reasoner in order to compute the subsumption hierarchy of the ontologies whose concepts are used in the OWL-S Profile descriptions as input and output concepts. The concept ranking algorithm is applied over this hierarchy in order to determine similar concepts based on different degrees of semantic matching relaxation, such as subclass or sibling hierarchical relationships. The domain independent planning systems role is to semantically search the space of possible compositions of Web services, generating plans according to the desirable level of relaxation.

Extending the Social Network Interaction Model to Facilitate Collaboration through Service Provision

Social network technology has been established as a prominent way of communication between members of an organization or enterprise. This paper presents an approach extending the typical social network interaction model to promote participant collaboration through service provision within an organization, towards the Enterprise 2.0 vision. The proposed interaction model between enterprise network participants incorporates their actual roles in the organization and enables the definition of custom relation types implementing custom policies and rules. It supports a complex mechanism for refined content propagation according to participant relations and/or roles. Moreover, the collaboration of participants to provide services and complete specific business tasks through Social Business Process Management is facilitated by enabling the execution of specific activities in each participant profile according to his/her actual role. To explore the potential of the proposed interaction model towards Enterprise 2.0, two prototype social networks, developed to serve different communities and needs, are discussed as case studies.

Using social network technology to provide e-administration services as collaborative tasks

This paper presents an approach employing social network technology to facilitate e-administration within collaborative communities. E-administration services are provided through task coordination between specific participants. Task activities are performed by gadgets acting on behalf of participants. Task assignment is based on participant roles and relations in the community, explicitly defined within the social network. Interaction between gadgets is governed by rules based on participant roles, dictating the obligations and responsibilities of each party. Whenever the execution of a certain gadget depends on the previous execution of a series of other gadgets, a recommendation mechanism employing AI planning is used to provide a plan according to which gadgets should be combined. The implementation of a social network platform supporting e-administration based on extending the OpenSocial API is also presented. The proposed platform has been utilized to develop a social network for the academic community, featuring pilot implementation of specific e-administration services.

Collaborative management of applications in enterprise social networks

Enterprise social networks are gaining momentum as a platform for collaboration between members of an enterprise, leading to the notion of Enterprise 2.0. Participant collaboration includes communication, information and data dissemination and also application execution, leading to task completion. This paper presents an approach extending social network data model to promote participant collaboration through collaborative application execution and management. The proposed extensions support not only process monitoring but actual execution, management and composition of applications within the context of the social network, in a uniform way. In order to achieve this effectively, external services must be wrapped and integrated in the social network environment as applications, and consequently they must be mapped to business tasks executed in each participant profile, according to their actual role and responsibilities in the enterprise. The social network framework must take into account the actual roles, relationships and responsibilities of the members of an enterprise, which, combined, dictate enterprise workflow schemes and policies. To explore the potential of the proposed approach, a prototype social network platform is discussed as a case study.