Keywords: Web service, data quality, data interpretation, semantics, context The Internet era has evolved from a Web of documents to a Web of services. Web services are intended to be application components that can be reused and integrated to create more advanced, innovative Web applications without needing to develop them from scratch. Unfortunately, Web services distributed on the Internet are usually independently developed by different organizations and/or individuals and have diverse assumptions about the interpretation of the exchanged data, such as inconsistent data representation and conceptualization. Such data misinterpretation can result in Data Quality (DQ) problems and hamper the potential of Web services. We identify important DQ challenges in Web services composition and present a classification of the resulting DQ problems. We suggest a novel reconciliation framework for addressing these problems and evaluate the framework in terms of scalability, adaptability, and extensibility. Finally, we identify important future directions in data quality and Web services. 1.

Abstract. This chapter tackles the relation between declarative languages and multi-agent systems by following the dictates of the five Ws (and one H) that characterize investigations. The aim is to present this research field, which has a long-term tradition, and discuss about its future. The first question to answer is “What? What are declarative agents and multi-agent systems?”. Therefore, we will introduce the history of declarative agent systems up to the state of the art by answering the question “When? When did research on them begin?”. We will, then, move to the question “Where? Where can it take place?”: in which kind of real applications and for which kind of problems declarative agents and MAS have already proven useful? Connected to where is “Why? Why should it happen?”. We will discuss the benefits of adopting the abstractions offered by declarative approaches for developing communication, interaction, cooperation mechanisms. We will compare with other technologies, mainly service-based and object-oriented ones. “Who? Who can be involved?”: in order to exploit this kind of technology what sort of background does a specialist have to acquire?

Abstract—Data-Providing (DP) services allow query-like access to organizations ’ data via web services. The invocation of a DP service results in the execution of a query over data sources. In most cases, users ’ queries require the composition of several services. In this paper, we propose a novel approach for querying and automatically composing DP services. The proposed approach largely draws from the experiences and lessons learned in the areas of service composition, ontology, and answering queries over views. First, we introduce a model for the description of DP services and specification of service-oriented queries. We model DP services as RDF views over a mediated (domain) ontology. Each RDF view contains concepts and relations from the mediated ontology to capture the semantic relationships between input and output parameters. Second, we propose query rewriting algorithms for processing queries over DP services. The query mediator automatically transforms a user’s query (during the query rewriting stage) into a composition of DP services. Finally, we describe an implementation and provide a performance evaluation of the proposed approach. Index Terms—Services integration framework, advanced services invocation framework, services delivery platform, composite web services. Ç 1

Abstract. Service-oriented computing (SOC) increases flexibility of IT systems and helps enterprises to meet their changing needs. Different methods address changing requirements in service-oriented environment. Many solutions exist to address variability, however, each solution is tailored to a specific problem, e.g. at one specific layer in SOC. We survey variability mechanisms from literature and summarize solutions, consequences, and possible combinations in a pattern catalogue. Based on the pattern catalogue, we compare different variability patterns and their combinations. Our catalogue helps to choose an appropriate technique for the variability problem at hand and illustrates its consequences in SOC. 1

Abstract. “Internet of things ” is a seminal vision of future technological ubiquity. It endows everyday objects with the ability to identify themselves, communicate with other objects, and possibly compute. While Radio-Frequency Identification (RFID) technologies have laid the foundation, the development of Service-Oriented Computing poses new opportunities for fully realizing the vision. The research proposal introduced in this paper proposes a methodology to realize the Internet of things in the service-centric environments. Major research challenges targeted by this methodology and possible solutions have been discussed.

Service-oriented Computing has recently received a lot of attention from both academia and industry. However, current service-oriented solutions are often not as dynamic and adaptable as intended because the publishfind-bind-execute cycle of the SOA triangle is not entirely realized. In this paper, we highlight some issues of current Web service technologies, with a special emphasis on service metadata, querying, invocation and mediation. We present the Vienna Runtime Environment for Service-oriented Computing (VRESCo) that aims at solving a number of these issues. Among others, VRESCO provides support for service metadata and querying, monitoring of Quality of Service, dynamic binding and invocation including service mediation, service notifications, and service compositions. Additionally, we give an evaluation that proves the performance and usefulness of our system.

algorithm for automatic Web service composition

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Service Oriented Computing (SOC) is a popular computing paradigm for the development of distributed Web applications. Service composition, a key element of SOC, is severely hampered by various types of semantic heterogeneity among the services. In this paper, we address the various semantic differences from the context perspective and use a lightweight ontology to describe the concepts and their specializations. Atomic conversions between the contexts are implemented using XPath functions and external services. The correspondences between the syntactic service descriptions and the semantic concepts are established using a flexible, standard-compliant mechanism. Given the naive BPEL composition ignoring semantic differences, our reconciliation approach can automatically determine and reconcile the semantic differences. The mediated BPEL composition incorporates necessary conversions to convert the data exchanged between different services. Our solution has the desirable properties (e.g., adaptability, extensibility and scalability) and can significantly alleviate the reconciliation efforts for Web services composition.

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