Semantic Web: An Integrated Approach for Web Service Discovery, Selection and Composition

Web services are remote methods can be invoked through open standards such as Simple Object Access Protocols. The increasing web services in the repositories makes the selection process very complex. The same can be extended in forming the composition of web services. This research focuses on the semantic web service selection and composition through design and implementation of a framework. The proposed framework is an ontology based service selection approach and the selected services are participating in the composition process. This approach deals with semantic search, which uses Quality of services for service selection and composition. The entire framework is implemented with semantic web technology and the performance of the system is observed with domain specific ontologies

Computational Complexity of Web Service Composition Based on Behavioral Descriptions

The Web Service Composition (WSC) problem on behav-ioral descriptions deals with the automatic construction of a coordinator web service to control a set of web services to reach the goal states. As such, WSC is one of the fundamen-tal techniques to enable the Service Oriented Architecture on the Web. Despite its importance and implications, how-ever, very few studies exist on the computational complexi-ties of the WSC problem. In this paper, we present two novel theoretical findings on WSC problems: (1) Solving the WSC problem with “complete ” information is EXP-hard, and (2) Solving the WSC problem with “incomplete ” information is 2-EXP-hard. These findings imply that more efforts to de-vise efficient approximate solutions to the WSC problem be needed. 1

SMT-based Abstract Temporal Planning

These are the proceedings of the International Workshop on Petri Nets and Software Engineering (PNSE’14) in Tunis, Tunisia, June 23–24, 2014. It is a co-located event of Petri Nets 2014, the 35th international conference on Applications and Theory of Petri Nets and Concurrency and ACSD 2014, the 14th International Conference on Application of Concurrency to System Design.An abstract planning is the first phase of the web service composition in the PlanICS framework. A user query specifies the initial and the expected state of a plan in request. The paper extends PlanICS with a module for temporal planning, by extending the user query with an LTL_k-X formula specifying temporal aspects of world transformations in a plan. Our solution comes together with an example, an implementation, and experimental results

WEB SERVICES COMPOSITION METHODS AND TECHNIQUES: A REVIEW

ABSTRAC

Type-Aware Web Service Composition Using Boolean Satisfiability Solver

The goal of the Web Service Composition (WSC) problem is to find an optimal “composition ” of web services to satisfy a given request using their syntactic and/or semantic features, when no single service satisfies it. In this paper, in particular, we study the WSC problem from semantic aspects, exploiting the supertype-subtype relationship among parameters, and propose a novel solution based on the boolean satisfiability problem (SAT). Given a set of web service descriptions and a requirement web service, we reduce the WSC problem into a reachability problem on a state-transition system, and show that the shortest path found is amount to the optimal composition. A preliminary experiment using 7 examples reveals that our proposal can find optimal compositions of web services efficiently. 1

Reasoning with qualitative preferences for optimization of component-based system development

A component-based system is a set of entities that work together in well-defined ways to satisfy a given requirement specified by the stakeholders for the system. This requirement can be modeled as a set of combinations of traits, which represent acceptable alternatives for providing the required functionality. A system satisfies its requirement if and only if it provides one of the required sets of traits in its entirety. Beyond the requirement, system stakeholders may also have preferences with respect to optional functionality that could be provided by a system, tradeoffs between non-functional properties, or other system design options. This work focuses on integrating support for both qualitative preference reasoning and formal verification into the component-based system design process in order to choose a set of components for the system that, when composed, will (1) satisfy the stakeholders\u27 requirement for the system and (2) provide a set of traits that is optimal with respect to the given preferences. Our primary research objective is to develop a generic, modular, end-to-end framework for developing component-based systems of any type which are correct according to the system requirement and most preferred with respect to the stakeholders\u27 preferences. Applications of the framework to problems in Web service composition, goal-oriented requirements engineering, and other areas will be discussed, along with future work toward integrating multi-stakeholder preference reasoning and partial satisfaction of traits into the framework

Semantic search and composition in unstructured peer-to-peer networks

This dissertation focuses on several research questions in the area of semantic search and composition in unstructured peer-to-peer (P2P) networks. Going beyond the state of the art, the proposed semantic-based search strategy S2P2P offers a novel path-suggestion based query routing mechanism, providing a reasonable tradeoff between search performance and network traffic overhead. In addition, the first semantic-based data replication scheme DSDR is proposed. It enables peers to use semantic information to select replica numbers and target peers to address predicted future demands. With DSDR, k-random search can achieve better precision and recall than it can with a near-optimal non-semantic replication strategy. Further, this thesis introduces a functional automatic semantic service composition method, SPSC. Distinctively, it enables peers to jointly compose complex workflows with high cumulative recall but low network traffic overhead, using heuristic-based bidirectional haining and service memorization mechanisms. Its query branching method helps to handle dead-ends in a pruned search space. SPSC is proved to be sound and a lower bound of is completeness is given. Finally, this thesis presents iRep3D for semantic-index based 3D scene selection in P2P search. Its efficient retrieval scales to answer hybrid queries involving conceptual, functional and geometric aspects. iRep3D outperforms previous representative efforts in terms of search precision and efficiency.Diese Dissertation bearbeitet Forschungsfragen zur semantischen Suche und Komposition in unstrukturierten Peer-to-Peer Netzen(P2P). Die semantische Suchstrategie S2P2P verwendet eine neuartige Methode zur Anfrageweiterleitung basierend auf Pfadvorschlägen, welche den Stand der Wissenschaft übertrifft. Sie bietet angemessene Balance zwischen Suchleistung und Kommunikationsbelastung im Netzwerk. Außerdem wird das erste semantische System zur Datenreplikation genannt DSDR vorgestellt, welche semantische Informationen berücksichtigt vorhergesagten zukünftigen Bedarf optimal im P2P zu decken. Hierdurch erzielt k-random-Suche bessere Präzision und Ausbeute als mit nahezu optimaler nicht-semantischer Replikation. SPSC, ein automatisches Verfahren zur funktional korrekten Komposition semantischer Dienste, ermöglicht es Peers, gemeinsam komplexe Ablaufpläne zu komponieren. Mechanismen zur heuristischen bidirektionalen Verkettung und Rückstellung von Diensten ermöglichen hohe Ausbeute bei geringer Belastung des Netzes. Eine Methode zur Anfrageverzweigung vermeidet das Feststecken in Sackgassen im beschnittenen Suchraum. Beweise zur Korrektheit und unteren Schranke der Vollständigkeit von SPSC sind gegeben. iRep3D ist ein neuer semantischer Selektionsmechanismus für 3D-Modelle in P2P. iRep3D beantwortet effizient hybride Anfragen unter Berücksichtigung konzeptioneller, funktionaler und geometrischer Aspekte. Der Ansatz übertrifft vorherige Arbeiten bezüglich Präzision und Effizienz