Test of several approaches for the composition of web services in meteorology.

International audienceComposition of web services is a powerful means to answer user needs in many domains. This communication focuses on applications in meteorology. This domain presents several particularities which are discussed. We present an overview of three main types of approaches in composition of web services: static plan, IA-plan and theorem proof. We confront these types of approaches to the specific case of meteorology which is not well studied by the research community in web services. We design a test bed that is capable of handling the key issues in meteorology. We have selected three approaches. We adapt them to our case and build three prototypes which are used in the test bed to point out weakness and strength of each approach. We find that current approaches do not fulfill needs in meteorology. We recommend an hybrid approach that combines the three in order to obtain an automatic and adaptative composition

A proposal for a thesaurus for web services in solar radiation

International audienceMetadata are necessary to discover, describe and exchange any type of information, resource and service at a large scale. A significant amount of effort has been made in the field of geography and environment to establish standards. Efforts still remain to address more specific domains such as renewable energies. This communication focuses on solar energy and more specifically on aspects in solar radiation that relate to geography and meteorology. A thesaurus in solar radiation is proposed for the keys elements in solar radiation namely time, space and radiation types. The importance of time-series in solar radiation is outlined and attributes of the key elements are discussed. An XML schema for encoding metadata is proposed. The exploitation of such a schema in web services is discussed. This proposal is a first attempt at establishing a thesaurus for describing data and applications in solar radiation

Modeling the dynamics of web-based service and resource-oriented digital ecosystems

The notion of digital species is broadened to include services and resources, special issues arise in modeling the dynamics and workflows with representations associated with these services and resources. To address these issues, this paper explores two different yet related approaches: the traditional BPEL-based workflow modeling approach and the Mashupbased Web approach. In this paper, we first demonstrate two examples of service-oriented and resource-oriented digital ecosystems on the Web. We then identify key issues pertinent to both types of DES. We discuss formal definition, specifications and issues of BPEL-based approach and Mashup-based modeling techniques with computational formalisms. Finally, we propose a hybrid approach to deal with modeling the dynamicsin processes associated with such Digital Ecosystems

DecSerFlow: Towards a Truly Declarative Service Flow Language

The need for process support in the context of web services has triggered the development of many languages, systems, and standards. Industry has been developing software solutions and proposing standards such as BPEL, while researchers have been advocating the use of formal methods such as Petri nets and pi-calculus. The languages developed for service flows, i.e., process specification languages for web services, have adopted many concepts from classical workflow management systems. As a result, these languages are rather procedural and this does not fit well with the autonomous nature of services. Therefore, we propose DecSerFlow as a Declarative Service Flow Language. DecSerFlow can be used to specify, enact, and monitor service flows. The language is extendible (i.e., constructs can be added without changing the engine or semantical basis) and can be used to enforce or to check the conformance of service flows. Although the language has an appealing graphical representation, it is grounded in temporal logic

0011/2011 - BPEL: Principais Conceitos e Uso Prático

Este trabalho apresenta o padrão para orquestração de serviços BPEL (Business Proccess Execution Language) focando na descrição dos construtos essenciais ao seu uso. O objetivo deste trabalho é ser um tutorial que facilite o uso do padrão por desenvolvedores com pouca experiência em desenvolvimento de serviços. Além disso, é realizada uma revisão bibliográfica de trabalhos recentes relacionados ao tema orquestração

Grid Data Management: Open Problems and New Issues

International audienceInitially developed for the scientific community, Grid computing is now gaining much interest in important areas such as enterprise information systems. This makes data management critical since the techniques must scale up while addressing the autonomy, dynamicity and heterogeneity of the data sources. In this paper, we discuss the main open problems and new issues related to Grid data management. We first recall the main principles behind data management in distributed systems and the basic techniques. Then we make precise the requirements for Grid data management. Finally, we introduce the main techniques needed to address these requirements. This implies revisiting distributed database techniques in major ways, in particular, using P2P techniques

Coordination Of Hierarchical Command And Control Services

The purpose of this program is to show emerging information technologies can significantly improve key areas of tactical operations, resulting in the conversion of software developed under the ATO to existing battlefield systems. One such key area is Information Dissemination and Management (ID&M). The key software that will be developed under the ID&M portion requires a collection of agent-based software services that will collaborate during tactical mission planning and execution

Automatic dynamic generation of likely invariants for WS-BPEL compositions

The wide adoption of Web Services has led to the development of languages to compose them, like the WS-BPEL standard. In order to check whether the composition works as expected, one common approach is to analyze it and infer functional properties describing its behavior. Traditional approaches for inferring properties in WS-BPEL have been static: compositions are transformed into specialized analysis models based on some formalization. However, this formalization could be inexact due to theoretical limitations or differing interpretations of the standard by implementers. Dynamic invariant generation solves these problems by extracting the properties from actual executions and has been successfully used in popular languages, but not to WS-BPEL yet. In this work, we apply dynamic invariant generation to WS-BPEL, providing innovative solutions for several features that require special consideration, like highly multidimensional values in variables, an advanced type system or unstructured code. We have implemented these solutions in Takuan and evaluated its performance with several compositions of varying complexity. We present the results obtained and a comparative analysis of the efficiency and effectiveness of our solutions. Results show that the solutions are successful in reducing the cost of applying dynamic invariant generation and the number of uninteresting invariants generated

Intelligent business processes composition based on mas, semantic and cloud integration (IPCASCI)

[EN]Component reuse is one of the techniques that most clearly contributes to the evolution of the software industry by providing efficient mechanisms to create quality software. Reuse increases both software reliability, due to the fact that it uses previously tested software components, and development productivity, and leads to a clear reduction in cost. Web services have become are an standard for application development on cloud computing environments and are essential in business process development. These services facilitate a software construction that is relatively fast and efficient, two aspects which can be improved by defining suitable models of reuse. This research work is intended to define a model which contains the construction requirements of new services from service composition. To this end, the composition is based on tested Web services and artificial intelligent tools at our disposal. It is believed that a multi-agent architecture based on virtual organizations is a suitable tool to facilitate the construction of cloud computing environments for business processes from other existing environments, and with help from ontological models as well as tools providing the standard BPEL (Business Process Execution Language). In the context of this proposal, we must generate a new business process from the available services in the platform, starting with the requirement specifications that the process should meet. These specifications will be composed of a semi-free description of requirements to describe the new service. The virtual organizations based on a multi-agent system will manage the tasks requiring intelligent behaviour. This system will analyse the input (textual description of the proposal) in order to deconstruct it into computable functionalities, which will be subsequently treated. Web services (or business processes) stored to be reused have been created from the perspective of SOA architectures and associated with an ontological component, which allows the multi-agent system (based on virtual organizations) to identify the services to complete the reuse process. The proposed model develops a service composition by applying a standard BPEL once the services that will compose the solution business process have been identified. This standard allows us to compose Web services in an easy way and provides the advantage of a direct mapping from Business Process Management Notation diagrams