An ontology modeling method in semantic composition of Web services

Managing Service Level Agreement (SLA) for composite semantic web services is a very complex process, as it involves many complex tasks such as components discovery, provisioning, monitoring, recovery, and coordination. Indeed, managing all these tasks manually is a very cumbersome operation, nevertheless it is time consuming and prone to errors. To overcome such problems, automated SLA management for composite semantic web services is needed. This requires the SLA of the composite service to be described in a machine-understandable format such that it can be understood and processed by the automated SLA management tool. Currently, there is no SLA description language for composite semantic web services, but there exists an SLA description language for atomic web services, known as the Web Service Level Agreement (WSLA). Hence, in this paper, we aim to extend the WSLA language to describe composite semantic web services' SLAs, then we show how we can automatically generate the components' SLAs from the composite semantic web services' SLAs; adopting the CRECENT framework that we previously proposed for managing composite web services.

Background/Objectives: This article proposes a novel methodology based on rubrics and feature-based schemes for the appraisal and comparison of approaches to semantic Web services composition and discovery. Methods/Statistical analysis: In order to evaluate the Semantic Web services composition and discovery approaches we created a new framework called RFSWS. This framework is the combination of traditional feature-based evaluation schemes and newly developed analytic rubrics tables. Five recently introduced prominent Semantic Web services composition approaches were identified, explained, and then evaluated/compared using RFSWS. Findings: In this work we determined aspects of Semantic Web services composition and discovery processes that can be evaluated as performance criteria in rubric tables. This is a novel application of rubrics, which have traditionally been used for grading student performance by teachers. We created a novel framework called RFSWS consisting of rubric tables and a feature-based evaluation scheme for the evaluation and comparison of Semantic Web service discovery and composition approaches, and applied it in the evaluation of five recently introduced prominent Semantic Web services composition approaches. Considering the shortcomings of existing Semantic Web services composition approaches that were discovered through this evaluation, we proposed an idealized dynamic Semantic Web service discovery and composition method, a yardstick by which all future Semantic Web services composition approaches can be evaluated. Application/ Improvements: Our novel RFSWS framework can be applied in the comprehensive and systematic evaluation/comparison of Semantic Web services discovery and composition approaches.

The automatic composition of Web Services has been explored in the literature from different standpoints. It aims to create an execution plan for the flow of Web Services based on requests made and sent by the client, by following the stages necessary for the generation of composite services and then carrying out the execution of the workflow that has been designed. However, no research studies have been found that undertake the whole process of an automatic composition and execution, from the user's request to the execution of the services chosen as a solution. Therefore, the goal of this paper is to evaluate the performance of an automatic Web Service composition, since the request made by the client, to the delivery of the results of the executed composition. This article examines the integration between two tools, the automatic web service composition system and the extensible platform to evaluate semantic web services with the aim of conducting a performance evaluation of an entire process of automatic composition of Web services.

The potential benefits of Web services composition heavily rely on semantic interoperability, i.e., the ability to exchange data meaningfully amongst Web services. Context heterogeneity, which refers to different implicit assumptions about interpreting the exchanged data, hampers the automatic composition of Web services. However, existing initiatives of Semantic Web Services (SWSs) often ignore context heterogeneity. In this paper, we introduce an approach to address this issue. The contexts of the involved Web services are defined in a lightweight ontology and their WSDL descriptions are annotated by an extension of a W3C standard, i.e., Semantic Annotation for WSDL and XML Schema (SAWSDL). The composition of Web services is described using BPEL specification. Given a BPEL file that ignores context heterogeneity, the approach automatically detects all context differences among the involved services, and reconciles them by producing a mediated BPEL file that incorporates necessary conversions using XPath functions and/or Web services.

The automatic composition of semantic Web services is one of challenging areas of semantic Web services research. Mathematical semantic Web services are very useful in practice, however only a small number of related research results are reported. In this paper, we will show a dynamic, automated composition method for mathematical semantic Web services, using intelligent agents. The paper is focused on solving a kind of mathematical puzzle, called the countdown problem. In addition, we will show a static, manual composition method for Web services.

Web services play an important role in the development of distributed systems. Particularly, the possibility of composing already implemented web services in order to provide new functionalities is an interesting approach for building distributed applications and business processes. In this paper we focus on mismatches occurring during dynamic composition of web services. We propose an algorithm for dynamic and automatic composition and adaptation of web services. Our approach only uses the information that is already available in service interface descriptions. The algorithm allows programmers to define dynamic web service compositions without changing the source code.

An important research challenge consists in composing web services in an automatic and distributed manner on a large scale. Indeed, most queries can not be satisfiable by one service and must be processed by composing several services. Each web service is often written by different designers and is described using the terms of their own ontology. Therefore, the composition process needs to deal with a variety of heterogeneous ontologies. In order to tackle this challenge, we propose an approach using Distributed Description Logics (DDL) to achieve the semantic composition of web services. DDL allows one to make semantic connections between ontologies and thus web services, as well as to reason to get a semantic composition of web services.

The growth of Web service formats over the Internet is increasing. These services should often be composed to achieve a user request. We propose in this paper a framework to cope with web service composition, from discovery to optimization. This framework, called SPOC, is composed of four successive phases: discovery, planning, quote execution and optimization. Only RFQ (Request for Quote) web services are treated in this first version of SPOC. The Discovery phase aims to search for web services in a repository. The Planning phase determines which services satisfy the user request. The Quote Execution phase involves processing a Request For Quote (RFQ) by calling web services. The last phase optimizes these results giving tradeoff compositions. As a proof-of-concept example, we applied SPOC to public competition processes in Public Markets.

Composition of Web services is a cornerstone step in the development of interoperable systems. However, Web services still face data-heterogeneity challenges, although several attempts of using semantics. In addition, the context in which Web services evolve is still somehow ”ignored”, hampering their adaptability to changes in composition situations. In this paper, we argue how context permits to determine the semantics of interfaces that Web services expose to third parties. We show the need for a context- and semantic-based approach for Web services composition.

A difficulty of sharing messages transferred among Web services is absence of common vocabulary, and the semantic organization and description of Web services is an important requirement for enabling the automatic discovery, selection, composition, execution and monitoring of Web services. This paper proposes a model for semantic-based interaction between Web services. The method defined some ontology-based vocabularies to describe different Web services and some mapping rules among those vocabularies. Compared with existing methods, the method considers the Web services together with the semantic interpretation, satisfiability and reasoning of distributed ontologies. So the method can ensure the share and reusage of term be used for describing parameters of Web services.

In a domain SOA environment, multiple services exist to help in executing the users requests but manually handling each request is time wasting and very tiring thus the idea of automatic composition of web services emerged. This paper describes the ACUAI framework which is an AI automatic composer for web services with learning capabilities, since games have the most developed dynamic system adaptation to user action this framework uses two AI techniques which are used in games development they are decision trees and the finite state machines, the user request will be handled in the same way games react to user input then a decision is taken based on current state of the orchestration and then the algorithm changes the state of the orchestration according to the last decision taken to be able to guide the orchestration towards the goal and get a successful composition then each successful composition and its template request are saved to be used later on in enhancing the execution time.

The automated composition of Web services is one of the most promising ideas and at the same time one of the most challenging research area for the taking off of service-oriented applications. It is widely recognised that one of the key elements for the automated composition of Web services is semantics, i.e. unambiguous descriptions of Web services capabilities and processes. However Web services described at capability level need a formal context to perform the automated composition of Web services. In this paper a TLB architecture (three levels based architecture) is presented to perform Web service composition. Moreover we introduce the composition process as a matchmaking of domains and solve the latter problem according to a formal model, i.e. the xCLM (eXtended causal link matrix) and a knowledge base of the domain

Through providing an execution environment for semantic web services, SWSF (Semantic Web Service Framework) can facilitate automatic web service delivery, discovery, selection, invoking, composition and interoperation. However, each of those ongoing approaches does not satisfy all basic requirements of SWSF, e.g. OWL-S (Ontology Language of Web Service) does not offer the mechanism for automatic web service tasks' execution and WSMO can not describe the composition of web services in a structural way yet. So, in order to provide a fully- fledged SWSF, we present the ISCF (Integrated Service Composition Framework) which is based on the OAA (Open Agent Architecture ). We describe the technical characters and design objectives of ISCF from global and detailed view. Comparing with other SWSFs, ISCF has more extensible and autonomous distributed architecture, and has more complete and effective web service automatization. In addition, ISCF provide some useful tools to help users design semantic web services and manage ISCF system.

With the growth of web service in quantity, it has become an urgent issue how to compose web service with effective method so as to capacitate web service providers to work cooperatively and exert greater function. The paper introduces web service composition method based on rules and meta-services. Meta services are the abstraction of web services with similar functions, while rules are used to describe logic relation and data dependence relation among meta-services. An algorithm that generates the abstract service composition process based on the rules and meta-services is designed. The abstract service composition process is converted into executable process by employing web service discovery. The method proposed in this paper is proved to be feasible by the application in travel platform.

Automated composition of Web services has received much interest in the last decade, as it supports B2B applications. It aims at selecting and inter-connecting services provided by different partners in response to client requests. Planning techniques are used widely in the literature to describe Web services composition problem. However, since Web services proliferate day after day, classical planners are no longer well suited to compose Web services in a reasonable time. This weakness is due to the explosion of the search space caused by the large number of services and the broad range of data exchanged among services. In this paper, we propose a decentralised multi-agent approach to solve the Web services composition problem at runtime. Our model consists of a set of Web service agents where each agent has a set of services organised in a graph. Responding to a request, agents propose partial plans which are partial paths in the graph, then they coordinate their partial plans to provide the best global plan for the submitted request. The analysis of the complexity and results of the implementation show the ability of our approach to scale up when compared to the of state-of-the-art techniques for automated web service composition.