A METHOD FOR SEMANTIC WEB SERVICE COMPOSITION BASED ON PATTERN MATCHING

The composition of semantic web services is a very important and actual problem in the semantic web services research area. There are several semi-automatic approaches for this problem, but most of the results are related to automatic approaches. In this paper we present an automatic approach for the composition of semantic web services based on pattern matching. We consider a special type of semantic description, represented as a list of semantic descriptions corresponding to several semantic web services. The semantic description related to the semantic web service that we want to obtain is decomposed until all the parts of the semantic description correspond to semantic web services from a library. In the end, all the necessary semantic web services found in the library are composed in order to obtain the semantic web service that we wanted to construct.semantic web service composition, semantic description decomposition, pattern matching

Constraint integration and violation handling for BPEL processes

Autonomic, i.e. dynamic and fault-tolerant Web service composition is a requirement resulting from recent developments such as on-demand services. In the context of planning-based service composition, multi-agent planning and dynamic error handling are still unresolved problems. Recently, business rule and constraint management has been looked at for enterprise SOA to add business flexibility. This paper proposes a constraint integration and violation handling technique for dynamic service composition. Higher degrees of reliability and fault-tolerance, but also performance for autonomously composed WS-BPEL processes are the objectives

A Constrained Object Model for Configuration Based Workflow Composition

Automatic or assisted workflow composition is a field of intense research for applications to the world wide web or to business process modeling. Workflow composition is traditionally addressed in various ways, generally via theorem proving techniques. Recent research observed that building a composite workflow bears strong relationships with finite model search, and that some workflow languages can be defined as constrained object metamodels . This lead to consider the viability of applying configuration techniques to this problem, which was proven feasible. Constrained based configuration expects a constrained object model as input. The purpose of this document is to formally specify the constrained object model involved in ongoing experiments and research using the Z specification language.Comment: This is an extended version of the article published at BPM'05, Third International Conference on Business Process Management, Nancy Franc

Service composition in stochastic settings

With the growth of the Internet-of-Things and online Web services, more services with more capabilities are available to us. The ability to generate new, more useful services from existing ones has been the focus of much research for over a decade. The goal is, given a specification of the behavior of the target service, to build a controller, known as an orchestrator, that uses existing services to satisfy the requirements of the target service. The model of services and requirements used in most work is that of a finite state machine. This implies that the specification can either be satisfied or not, with no middle ground. This is a major drawback, since often an exact solution cannot be obtained. In this paper we study a simple stochastic model for service composition: we annotate the tar- get service with probabilities describing the likelihood of requesting each action in a state, and rewards for being able to execute actions. We show how to solve the resulting problem by solving a certain Markov Decision Process (MDP) derived from the service and requirement specifications. The solution to this MDP induces an orchestrator that coincides with the exact solution if a composition exists. Otherwise it provides an approximate solution that maximizes the expected sum of values of user requests that can be serviced. The model studied although simple shades light on composition in stochastic settings and indeed we discuss several possible extensions

Learning Services Based on Formal Concept Reasoning

A formal foundation of automated service discovering for Semantic Web is proposed. The approach is based on the formalization of the problem using an agent oriented programming language (ConGolog), as well as on the use of the Formal Concept Analysis as a tool for knowledge extraction.Ministerio de Educación y Ciencia TIN 2004- 0388

Planning and monitoring the execution of web service requests

Interaction with web services enabled marketplaces would be greatly facilitated if users were given a high level service request language to express their goals in complex business domains. This could be achieved by using a planning framework which monitors the execution of planned goals against predefined standard business processes and interacts with the user to achieve goal satisfaction. We present a planning architecture that accepts high level requests, expressed in XSRL (Xml Service Request Language). The planning framework is based on the principle of interleaving planning and execution. This is accomplished on the basis of refinement and revision as new service-related information is gathered from UDDI and web services instances, and as execution circumstances necessitate change. The system interacts with the user whenever confirmation or verification is needed

An Effective Strategy for the Flexible Provisioning of Service Workflows

Recent advances in service-oriented frameworks and semantic Web technologies have enabled software agents to discover and invoke resources over large distributed systems, in order to meet their high-level objectives. However, most work has failed to acknowledge that such systems are complex and dynamic multi-agent systems, where service providers act autonomously and follow their own decision-making procedures. Hence, the behaviour of these providers is inherently uncertain - services may fail or take uncertain amounts of time to complete. In this work, we address this uncertainty and take an agent-oriented approach to the problem of provisioning service providers for the constituent tasks of abstract workflows. Specifically, we describe an algorithm that uses redundancy to deal with unreliable providers, and we demonstrate that it achieves an 8-14% improvement in average utility over previous work, while performing up to 6 times as well as approaches that do not consider service uncertainty. We also show that our algorithm performs well in the presence of inaccurate service performance information

Dynamic orchestration of distributed services on interactive community displays: the ALIVE approach

Interconnected service providers constitute a highly dynamic, complex, distributed environment. Multi-agent system design-methodologies have been try-ing to address this kind of environments for a long time. The European project ALIVE presents a framework of three interconnected levels that tackles this issue relying on organisation and coordination techniques, as well as on developments in the Web-services world. This paper presents initial results focused on a high-tech, real use case: interactive community displays with touristic information and services, dynamically personalized according to user preferences and local laws.Peer ReviewedPreprin

Building a Context World for Dynamic Service Composition

Dynamic service composition requires responding and adapting to changes in the computing environment when orchestrating existing services into one or more new services that fit better to a composite application. This paper abstracts the changes of the environment as a context world to store the physical contexts of the computing environment, user profiles and computed results of services as well. We use ontology techniques to model the domain concepts of application contexts. Context Condition/Effect Description Language is designed to describe the dynamic semantics of the requirements and capabilities of goals and services in a concise and editable manner. Goal-driven and planning techniques are used to dynamically implement the service composition according to the domain knowledge and facts in the context world. ?2010 IEEE.EI

Design of a framework for automated service mashup creation and execution based on semantic reasoning

Instead of building self-contained silos, applications are being broken down in independent structures able to offer a scoped service using open communication standards and encoding. Nowadays there is no automatic environment for the construction of new mashups from these reusable services. At the same time the designer of the mashup needs to establish the actual locations for deployment of the different components. This paper introduces the development of a framework focusing on the dynamic creation and execution of service mashups. By enriching the available building blocks with semantic descriptions, new service mashups are automatically composed through the use of planning algorithms. The composed mashups are automatically deployed on the available resources making optimal use of bandwidth, storage and computing power of the network and server elements. The system is extended with dynamic recovery from resource and network failures. This enrichment of business components and services with semantics, reasoning, and distributed deployment is demonstrated by means of an e-shop use case