Web Services Composition Methods and Techniques: A Review <s> 2.G: Description Languages of Web Services <s> Business applications are more and more often developed on the basis of Web services. The aim is to provide platform independence and loose coupling between business applications to facilitate distributed and grid computing scenarios. However, most efforts to deploy and publish Web services are manual. Manual discovery, invocation and composition of Web services in a distributed computing environment significantly hamper the automatic process of enterprise application integration. Semantic enhancements in Web services aim at making the process of Web services discovery, invocation and composition dynamic by exposing the machine understandable description of Web service capabilities and Web service requests. In this paper we compare recent dynamic Web service composition approaches. We highlight some dynamic composition issues and compare existing approaches with respect to these issues. Based on these findings we present a new and generic semantic Web services integration and composition lifecycle to facilitate the semantic based integration and composition of grid services. The proposed semantic Web services integration and composition life cycle explains the necessary integration phases beginning with the modeling and developing of processes as Web service composition and ending with their execution. With this lifecycle, integration hurdles among different service composition approaches will be diminished. <s> BIB001 </s> Web Services Composition Methods and Techniques: A Review <s> 2.G: Description Languages of Web Services <s> Web services are important for creating distributed applications on the Web. In fact, they're a key enabler for service-oriented architectures that focus on service reuse and interoperability. The World Wide Web Consortium (W3C) has recently finished work on two important standards for describing Web services the Web Services Description Language (WSDL) 2.0 and Semantic Annotations for WSDL and XML Schema (SAWSDL). Here, the authors discuss the latter, which is the first standard for adding semantics to Web service descriptions. <s> BIB002 </s> Web Services Composition Methods and Techniques: A Review <s> 2.G: Description Languages of Web Services <s> With the development of Internet and information sharing, semantic web attracts many re-searchers' attention in computer field. Web service composition is an important technology in domain of Web service. As integrated solution for realizing the vision of the next generation of the web, semantic web services combine the semantic web technology with web service technology, and thus enable automated discovery, selection, composition and execution of web services. Ontology is the theoretical foundation of semantic web services. Qos ontology of web services description is introduced. In this paper, a new composition algorithm of semantic Web service based on QoS ontology is proposed. Experiments are carried out to compare the new algorithm with some other web service composition algorithms. <s> BIB003 </s> Web Services Composition Methods and Techniques: A Review <s> 2.G: Description Languages of Web Services <s> This paper presents a semi-automatic Web service composition approach. This approach ranks all available candidate Web service operations based on semantic annotations and suggests service operations to a human designer during the process of Web service composition. The ranking scores are based on data mediation, functionality and formal service specifications. A formal graph model, an IODAG, is defined to formalize an input/output schema of a Web service operation. Three data mediation algorithms are developed to handle the data heterogeneities arising during Web service composition. The data mediation algorithms analyze the schemas of the inputs and outputs of service operations and consider the structures of the schemas. A typed representation for our data mediation approach, which formalizes the data mediation problem as a subtype-checking problem, is presented. An evaluation is performed to study the effectiveness of different data mediation and service suggestion algorithms used to assist designers composing Web services. <s> BIB004 </s> Web Services Composition Methods and Techniques: A Review <s> 2.G: Description Languages of Web Services <s> This paper proposes a semantic Web service discovery framework for finding semantic Web services by making use of natural language processing techniques. The framework allows searching through a set of semantic Web services in order to find a match with a user query consisting of keywords. By specifying the search goal using keywords, end-users do not need to have knowledge about semantic languages, which makes it easy to express the desired semantic Web services. For matching keywords with semantic Web service descriptions given in WSMO, techniques like part-of-speech tagging, lemmatization, and word sense disambiguation are used. After determining the senses of relevant words gathered from Web service descriptions and the user query, a matching process takes place. The performance evaluation shows that the three proposed matching algorithms are able to effectively perform matching and approximate matching. <s> BIB005
A web service usually has one or more operations. The input, output, precondition and effects (IOPE) are generally used to describe web service operation. Moreover, the syntactic name and the semantic annotation of Web service operation indicate its functionality BIB004 .Thus, languages such as UDDI, WSDL, SOAP, WSDL-S, OWL-S and so on are define standard ways for service discovery, description and invocation (message passing). The description of web services is divided into two groups: The main goal of syntactic descriptions of web services such as the Web Service Description Language is to describe interfaces of web services. The web services at the syntactical level are insufficient for creating meaningful descriptions of web services BIB001 .WSDL does not support from the specifications of various constraints, management statements, classes of service, Service Level Agreement (SLAs) and other contracts and protocols between web services. Thus, the concept of Semantic Web Service (SWS) has been established BIB005 [21]. • Semantic Description Service descriptions are provided in a semantic framework that is the combination of ontologies, and also they are used to describing software artefacts. One example of a language that facilitates capability-driven description of services is OWL-S and other semantic description languages there are such as WSDL-S, WSMO, SAWSDL and etc. OWL-S is made based on Web Ontology Language and consists of different Ontologies for describing Web service. Because OWL-S uses from ontologies to describe web services, web services and their behavior are become machine interpretable and thus tasks such as discovery and composition can be automated. OWL-S provide using of three different Ontologies: a Service Profile that states what the web service does, a Service Model that describe how the Web service performs the tasks and a Service Grounding that describes how to access the web service BIB005 . WSMO is another initiative to develop specifications for SWSs and is a framework for describing Web services. It consists of four top-entities: Ontology, Web Service, Goal and Mediator; Ontology provides the terminology that is used by other WSMO elements. Web Service describes the capabilities, interfaces and internal working of web services. Goal represents user desires and Mediator provides bridges between different Ontologies. WSMO uses from a specific designed language that is called Web Service Modeling Language (WSML) and. Also it contains a grounding feature to link concepts with WSDL data types that can be achieved automatic invocation BIB005 . As well as, SAWSDL is a set of extensions for WSDL that provides a standard description format for Web services. Indeed, SAWS-DL extends WSDL with pointers to semantics that are crucial for achieving automation. The major technologies for Web services are SOAP and WSDL BIB002 .Semantic web services combine the semantic web technology with web service technology, thus it enable automated discovery, selection, composition and execution of web services BIB003 . As a result, WSDL solves the need of interoperability in a technical manner, but is lacks adding semantic information.