Infraware: um middleware de suporte a aplicações sensíveis ao contexto

New mobile computing technologies and the increasing use of portable devices make computers more present on human life activities with each passing day. This favors the rising of a new computing paradigm: the Ubiquitous Computing. In this scenario, context-aware mobile applications stand out among others, improving user interaction by supporting new adaptive behavior according to context changes. Recent research points out the need for developing specialized middleware infrastructure for the management of dynamic contextual information. These new infrastructures provide the adequate facilities for the development of a large range of contextaware mobile applications, in several domains. This work proposes the design of a middleware to support the development and execution of context-aware applications. The architecture is defined by using relevant functional requirements of this new class of applications. Related aspects of the middleware s main components are presented. This work also presents the design and implementation of an essential component of the proposed middleware, responsable for the inference of new context information and context perception.O desenvolvimento de novas tecnologias de computação móvel e o crescente emprego de dispositivos portáteis têm tornado a computação cada vez mais presente na realização de diversas atividades humanas, favorecendo o surgimento de um novo paradigma computacional: a Computação Ubíqua. Nesse novo cenário, destacam-se as aplicações móveis sensíveis ao contexto, que aprimoram a interação com os seus usuários ao se beneficiarem do uso de informações contextuais. Pesquisas recentes destacam a necessidade do desenvolvimento de infra-estruturas especializadas de middleware para o gerenciamento de informações contextuais dinâmicas. Essas novas infra-estruturas fornecem facilidades adequadas ao desenvolvimento de uma ampla variedade de aplicações móveis, sensíveis ao contexto, em domínios diversos. Este trabalho propõe uma arquitetura de middleware para suporte ao desenvolvimento e execução de aplicações móveis sensíveis ao contexto. A arquitetura é definida a partir do levantamento de requisitos funcionais representativos para essa nova classe de aplicações. Aspectos relacionados aos principais componentes da arquitetura são apresentados. O trabalho também apresenta o projeto e implementação de um dos componentes essenciais da arquitetura proposta, responsável pela inferência de novas informações contextuais e pela percepção de contexto

Towards requirements elicitation in service-oriented business networks using value and goal modelling

Due to the contemporary trends towards increased focus on core competences and outsourcing of non-core activities, enterprises are forming strategic alliances and building business networks. This often requires cross enterprise interoperability and integration of their information systems, leading to widespread adoption of Service Oriented Architectures (SOA). In this paper we present an approach to guide the development and evolution of service-oriented business networks. Our approach combines value models and goal models, where the former are used to represent and analyse the economic sustainability of a business network and the latter are used to represent and analyse the goals of the participants within the business network. Systematic guidelines are proposed to derive a goal model from a value model. In addition, a preliminary discussion is presented on how to refine goals and operationalize goals as services rooted in a SOA. The approach is illustrated using an example of a business network in the electricity sector

Model-Driven Development of a Mediation Service

Although service-oriented architectures offer real benefits when pursuing application integration and business flexibility, there are still no satisfactory solutions for dealing with existing systems that need to cooperate while their services have no perfect match. In the case of incompatible services, a 'mediator' may be introduced which resolves (semantic) interoperability problems by intervening in the cooperation between systems. Building mediators is currently often a manual process, resulting in dedicated IT-driven solutions. This paper presents a framework to guide the development of mediators, with the following objectives: (i) uncover and capture the actual interoperability problem that needs to be solved; (ii) allow the involvement of non-IT (i.e., business) experts in the development of the solution; (iii) support evolution of the solution and re-use of results in case of changing interoperability requirements; (iv) facilitate automation of parts of the process. The framework is based on service-oriented, model-driven and semantic web techniques. Available tool support for the different steps in the framework is indicated

3-Fluoropyridine

Service-Oriented Architecture (SOA) claims to facilitate the construction of flexible and loosely coupled business applications, and therefore is seen as an enabling factor for enterprise interoperability. The concept of service, which is central to SOA, is very convenient to address the matching of needs and capabilities in enterprise collaborations. In order to satisfy more demanding needs or to rapidly adapt to changing needs it is possible to perform service composition in order to combine the capabilities provided through several available services. This paper presents a survey on recent approaches for service composition. To perform this study a conceptual framework for service composition is proposed. This framework allows studying how different approaches deal with the service composition life-cycle and provides basic guidelines for their analysis, evaluation and comparison. The proposed framework is used to analyse five representative service composition approaches

Model-driven Development of Mediation for Business Services Using COSMO

Although service-oriented architectures offer real benefits when pursuing business integration and flexibility, there are still no satisfactory solutions to accomplish cooperation between services of existing systems that have no perfect match. In the case of incompatible services, a 'mediator' may be introduced which resolves semantic and syntactic interoperability problems by intervening in the cooperation between systems. Building mediators is currently often a manual process, resulting in dedicated IT-driven solutions, with no concern for re-use of process, models or code. This paper presents a framework to guide the development of mediators, with the following objectives: (i) uncover and capture the actual interoperability problem that needs to be solved; (ii) allow the involvement of non-IT (i.e., business) experts in the development of the solution; (iii) support evolution of the solution and re-use of results in case of changing interoperability requirements; (iv) facilitate automation of parts of the process. The framework is based on service-oriented and model-driven techniques. Available tool support for the different elements in the framework is indicated

Model-driven service integration using the COSMO framework

The goal of the SWS Challenge is to explore the trade-offs of various existing technologies that aim at automation of mediation, choreography and discovery of Web Services. For that reason, the SWS Challenge defines a number of scenarios providing a standard set of problems, based on industrial specifications and requirements. In this paper, we present a model-driven approach for solving the integration problem described in the Purchase Order Mediation scenario of the SWS Challenge. The key feature of our approach is that service models are employed at different abstraction levels to develop end-to-end integration solutions from business requirements to software implementation. Model-driven techniques are used to abstract the integration problem and solution to a higher (platform-independent) level. This way, the problem and solution can be captured in a technology independent manner enabling more active participation of business domain experts

A MOF Metamodel for the Development of Context-Aware Mobile Applications

Context-aware mobile applications are increasingly attracting interest of the research community. To facilitate the development of this class of applications, it is necessary that both applications and support platforms share a common context metamodel. This paper presents a metamodel defined using the OMG Meta Object Facility (MOF). This metamodel has been used as basis for the development of context-aware applications and an associated service platform