A formal model for classifying trusted Semantic Web Services

Semantic Web Services (SWS) aim to alleviate Web service limitations, by combining Web service technologies with the potential of Semantic Web. Several open issues have to be tackled yet, in order to enable a safe and efficient Web services selection. One of them is represented by trust. In this paper, we introduce a trust definition and formalize a model for managing trust in SWS. The model approaches the selection of trusted Web services as a classification problem, and it is realized by an ontology, which extends WSMO. A prototype is deployed, in order to give a proof of concept of our approach

QoS based Effective and Efficient Selection of Web Service and Retrieval of Search Information

Web services are integrated software components for the support of interoperable machine to machine interaction over a network. Web services have been widely employed for building service-oriented applications in both industry and academia in recent years. The number of publicly available Web services is steadily increasing on the Internet. However, this proliferation makes it hard for a user to select a proper Web service among a large amount of service candidates. An inappropriate service selection may cause many problems to the resulting applications. In this paper, a novel collaborative filtering-based Web service recommender system is proposed to help the users and select services with optimal QoS performance. Our recommender system employ an effective and efficient selection of web services and relevant retrieval of information and makes personalized service recommendation to users based on the clustering results. Compared with existing service recommendation methods, the proposed approach achieves considerable improvement on the recommendation accuracy and the QoS performance metrics adopted in this paper shows the better accuracy and relevant web services

Selection of Composable Web Services Driven by User Requirements

International audienceBuilding a composite application based on Web services has become a real challenge regarding the large and diverse service space nowadays. Especially when considering the various functional and non-functional capabilities that Web services may afford and users may require. In this paper, we propose an approach for facilitating Web service selection according to user requirements. These requirements specify the needed functionality and expected QoS, as well as the composability between each pair of services. The originality of our approach is embodied in the use of Relational Concept Analysis (RCA), an extension of Formal Concept Analysis (FCA). Using RCA, we classify services by their calculated QoS levels and composability modes. We use a real case study of 901 services to show how to accomplish an efficient selection of services satisfying a specified set of functional and non-functional requirements

Assessing Web Services Interfaces with Lightweight Semantic Basis

In the last years, Web Services have become the technological choice to materialize the Service-Oriented Computing paradigm. However, a broad use of Web Services requires efficient approaches to allow service consumption from within applications. Currently, developers are compelled to search for suitable services mainly by manually exploring Web catalogs, which usually show poorly relevant information, than to provide the adequate "glue-code" for their assembly. This implies a large effort into discovering, selecting and adapting services. To overcome these challenges, this paper presents a novel Web Service Selection Method. We have defined an Interface Compatibility procedure to assess structural-semantic aspects from functional specifications - in the form of WSDL documents - of candidate Web Services. Two different semantic basis have been used to define and implement the approach: WordNet, a widely known lexical dictionary of the English language; and DISCO, a database which indexes co-occurrences of terms in very large text collections. We performed a set of experiments to evaluate the approach regarding the underlying semantic basis and against third-party approaches with a data-set of real-life Web Services. Promising results have been obtained in terms of well-known metrics of the Information Retrieval field

Web services choreography testing using semantic service description

Web services have become popular due to their ability to integrate with and to interoperate heterogeneous applications. Several web services can be combined into a single application to meet the needs of users. In the course of web services selection, a web candidate service needs to conform to the behaviour of its client, and one way of ensuring this conformity is by testing the interaction between the web service and its user. The existing web services test approaches mainly focus on syntax-based web services description, whilst the semantic-based solutions mostly address composite process flow testing. The aim of this research is to provide an automated testing approach to support service selection during automatic web services composition using Web Service Modeling Ontology (WSMO). The research work began with understanding and analysing the existing test generation approaches for web services. Second, the weaknesses of the existing approaches were identified and addressed by utilizing the choreography transition rules of WSMO in an effort to generate a Finite State Machine (FSM). The FSM was then used to generate the working test cases. Third, a technique to generate an FSM from Abstract State Machine (ASM) was adapted to be used with WSMO. This thesis finally proposed a new testing model called the Choreography to Finite State Machine (C2FSM) to support the service selection of an automatic web service composition. It proposed new algorithms to automatically generate the test cases from the semantic description (WSMO choreography description). The proposed approach was then evaluated using the Amazon E-Commerce Web Service WSMO description. The quality of the test cases generated using the proposed approach was measured by assessing their mutation adequacy score. A total of 115 mutants were created based on 7 mutant operators. A mutation adequacy score of 0.713 was obtained. The experimental validation demonstrated a significant result in the sense that C2FSM provided an efficient and feasible solution. The result of this research could assist the service consumer agents in verifying the behaviour of the Web service in selecting appropriate services for web service composition

Social networks : service selection and recommendation

University of Technology, Sydney. Faculty of Engineering and Information Technology.The Service-Oriented Computing paradigm is widely acknowledged for its potential to revolutionize the world of computing through the utilization of Web services. It is expected that Web services will fully leverage the Semantic Web to outsource some of their functionalities to other Web services that provide value-added services, and by integrating the business logic of Web services in the form of business to business and business to consumer e-commerce applications. In the Service Web, Web services and Web-Based Social Networks are emerging in which a wide range of similar functionalities are expected to be offered by a vast number of Web services, and applications can search and compose services according to users’ needs in a seamless and an automatic fashion. Web services are expected to outsource some of their functionalities to other Web services. In such situations, some services may be new to the service market, and some may act maliciously in order to be selected. A key requirement is to provide mechanisms for quality selection and recommendation of relevant Web services with perceived risk considerations. Although the future of Web service selection and recommendation looks promising, there are challenging issues related to user knowledge and behavior, as well as issues related to recommendation approaches. This dissertation addresses the demanding issues in Web service selection and recommendation from theory and practice perspectives. These challenges include cold-start users, who represent more than 50% of the social network population, the capture of users’ preferences, risk mitigation in service selection, customers’ privacy and application scalability. This dissertation proposes a novel approach to automate social-based Web service selection and recommendation in a dynamic environment. It utilizes Web-Based Social Networks and the “Follow the Leader” strategy, for a Credibility-based framework that includes two credibility models: the user Credibility model which is used to qualify consumers as either leaders or followers based on their credibility, and the service Credibility model which is used to identify the best services that act as market leaders. Experimental evaluation results demonstrate that the social network service selection and recommendation approach utilizing the credibility-based framework and “Follow the Leader” strategy provides an efficient, effective and scalable provision of credible services, especially for cold-start users. The research results take a further step towards developing a social-based automated and dynamically adaptive Web service selection and recommendation system in the future

Dynamic random testing of web services: a methodology and evaluation

In recent years, Service Oriented Architecture (SOA) has been increasingly adopted to develop distributed applications in the context of the Internet. To develop reliable SOA-based applications, an important issue is how to ensure the quality of web services. In this paper, we propose a dynamic random testing (DRT) technique for web services, which is an improvement over the widely-practiced random testing (RT) and partition testing (PT). We examine key issues when adapting DRT to the context of SOA, including a framework, guidelines for parameter settings, and a prototype for such an adaptation. Empirical studies are reported where DRT is used to test three real-life web services, and mutation analysis is employed to measure the effectiveness. Our experimental results show that, compared with the three baseline techniques, RT, Adaptive Testing (AT) and Random Partition Testing (RPT), DRT demonstrates higher fault-detection effectiveness with a lower test case selection overhead. Furthermore, the theoretical guidelines of parameter setting for DRT are confirmed to be effective. The proposed DRT and the prototype provide an effective and efficient approach for testing web services. IEE

Middleware Architecture for Evaluation and Selection of 3rd Party Web Services for Service Providers

Abstract — This paper presents an architecture to facilitate efficient evaluation and selection of 3rd party web services for service providers. Most service provider architectures have primarily focused on providing web service front ends to legacy systems, aggregating and delivering services via workflows. These architectures primarily considered static business contracts between the service provider and its (webservice enabled) business partners. This approach makes these architectures inflexible to variations in business requirement, partners ’ performance and customer requirements. Our architecture provides a flexible means for service providers to optimize business performance. Based on the historical performance, extant context, and optimising business rules, the appropriate service is selected and invoked to serve a customer request. We have developed a prototype of our system, dubbed ODSS-in-ENDS that integrates business partners and displays the dynamic evaluation and selection of services. I