605 research outputs found
A Formal Model of Semantic Web Service Ontology (WSMO) Execution
Semantic Web Services have been one of the most significant research areas within the Semantic Web vision, and have been recognized as a promising technology that exhibits huge commercial potential. Current Semantic Web Service research focuses on defining models and languages for the semantic markup of all relevant aspects of services, which are accessible through a Web service interface. The Web Service Modelling Ontology (WSMO) is one of the most significant Semantic Web Service framework proposed to date. To support the standardization and tool support of WSMO, a formal semantics of the language is highly desirable. As there are a few variants of WSMO and it is still under development, the semantics of WSMO needs to be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z semantics of WSMO. Different aspects of the language have been precisely defined within one unified framework. This model provides a formal unambiguous specification, which can be used to develop tools and facilitate future development
Discovery and composition of web services using artificial intelligence planning and web service modeling ontology
In today’s Web environment, Web services are the preferred standards-based way to realize Service Oriented Architecture (SOA) computing. A problem that has become one of the recent critical issues is automated discovery and composition of Semantic Web services. A number of approaches have been presented to solve the problem. However, most of these approaches only consider discovery or composition of Web services but not both. In this study, an effective approach called AIMO, based on Artificial Intelligence (AI) planning, Web Service Modeling Ontology (WSMO), and Semantic Web has been proposed to tackle the problem. The main purpose of this study is to investigate and develop a novel approach for automated Web service discovery and composition. In this case, a comparative evaluation of state-of-the-art approaches for Web service composition approaches has been done and the strengths and weaknesses of those approaches have been discussed. Moreover a translator for interaction between WSMO and AI-planning based on Description Logics has been proposed. In addition, some parts of AIMO architecture have been tested on a practical case study, and the results based on the experimental validation demonstrate that AIMO provides an effective and applicable solution. AIMO continues to support loose coupling paradigm of SOA by separating the discovery from the composition of Web services
Formalizing Web Service Choreographies
Current Web service choreography proposals, such as BPEL4WS, BPSS, WSFL, WSCDL or WSCI, provide notations for describing the message flows in Web service collaborations. However, such proposals remain at the descriptive level, without providing any kind of reasoning mechanisms or tool support for checking the compatibility of Web services based on the proposed notations. In this paper we present the formalization of one of these Web service choreography proposals (WSCI), and discuss the benefits that can be obtained by such formalization. In particular, we show how to check whether two or more Web services are compatible to interoperate or not, and, if not, whether the specification of adaptors that mediate between them can be automatically generated ---hence enabling the communication of (a priori) incompatible Web services
Reasoning About a Service-oriented Programming Paradigm
This paper is about a new way for programming distributed applications: the
service-oriented one. It is a concept paper based upon our experience in
developing a theory and a language for programming services. Both the
theoretical formalization and the language interpreter showed us the evidence
that a new programming paradigm exists. In this paper we illustrate the basic
features it is characterized by
INFRAWEBS BPEL-Based Editor for Creating the Semantic Web Services Description
INFRAWEBS project [INFRAWEBS] considers usage of semantics for the complete lifecycle of
Semantic Web processes, which represent complex interactions between Semantic Web Services. One of the
main initiatives in the Semantic Web is WSMO framework, aiming at describing the various aspects related to
Semantic Web Services in order to enable the automation of Web Service discovery, composition, interoperation
and invocation. In the paper the conceptual architecture for BPEL-based INFRAWEBS editor is proposed that is
intended to construct a part of WSMO descriptions of the Semantic Web Services. The semantic description of
Web Services has to cover Data, Functional, Execution and QoS semantics. The representation of Functional
semantics can be achieved by adding the service functionality to the process description. The architecture relies
on a functional (operational) semantics of the Business Process Execution Language for Web Services
(BPEL4WS) and uses abstract state machine (ASM) paradigm. This allows describing the dynamic properties of
the process descriptions in terms of partially ordered transition rules and transforming them to WSMO framework
Detecting Ontological Conflicts in Protocols between Semantic Web Services
The task of verifying the compatibility between interacting web services has
traditionally been limited to checking the compatibility of the interaction
protocol in terms of message sequences and the type of data being exchanged.
Since web services are developed largely in an uncoordinated way, different
services often use independently developed ontologies for the same domain
instead of adhering to a single ontology as standard. In this work we
investigate the approaches that can be taken by the server to verify the
possibility to reach a state with semantically inconsistent results during the
execution of a protocol with a client, if the client ontology is published.
Often database is used to store the actual data along with the ontologies
instead of storing the actual data as a part of the ontology description. It is
important to observe that at the current state of the database the semantic
conflict state may not be reached even if the verification done by the server
indicates the possibility of reaching a conflict state. A relational algebra
based decision procedure is also developed to incorporate the current state of
the client and the server databases in the overall verification procedure
Formalization of SOA concepts with mathematical foundation
With the development of the IT industry, agility and dynamicity are the two expected characteristics from any business enterprise. Service oriented architecture (SOA) is emerging as a promising approach aiming to address the current trends/needs of enterprise business applications. The current work aims at giving an overview of the conceptual model of SOA based on set theory approach. Also, it posits mathematical definitions for service, logical service, environment service and application definition with the help of general systems theory and mathematical foundation. With the help of mathematical model, the definition and functionality of services enhances SOA principles which can be used efficiently in integrating heterogeneous components
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