Towards runtime discovery, selection and composition of semantic services

Service-orientation is gaining momentum in distributed software applications, mainly because it facilitates interoperability and allows application designers to abstract from underlying implementation technologies. Service composition has been acknowledged as a promising approach to create composite services that are capable of supporting service user needs, possibly by personalising the service delivery through the use of context information or user preferences. In this paper we discuss the challenges of automatic service composition, and present DynamiCoS, which is a novel framework that aims at supporting service composition on demand and at runtime for the benefit of service end-users. We define the DynamiCoS framework based on a service composition life-cycle. Framework mechanisms are introduced to tackle each of the phases and requirements of this life-cycle. Semantic services are used in our framework to enable reasoning on the service requests issued by end users, making it possible to automate service discovery, selection and composition. We validate our framework with a prototype that we have built in order to experiment with the mechanisms we have designed. The prototype was evaluated in a testing environment using some use case scenarios. The results of our evaluation give evidences of the feasibility of our approach to support runtime service composition. We also show the benefits of semantic-based frameworks for service composition, particularly for end-users who will be able to have more control on the service composition process

GSO: Designing a Well-Founded Service Ontology to Support Dynamic Service Discovery and Composition

A pragmatic and straightforward approach to semantic service discovery is to match inputs and outputs of user requests with the input and output requirements of registered service descriptions. This approach can be extended by using pre-conditions, effects and semantic annotations (meta-data) in an attempt to increase discovery accuracy. While on one hand these additions help improve discovery accuracy, on the other hand complexity is added as service users need to add more information elements to their service requests. In this paper we present an approach that aims at facilitating the representation of service requests by service users, without loss of accuracy. We introduce a Goal-Based Service Framework (GSF) that uses the concept of goal as an abstraction to represent service requests. This paper presents the core concepts and relations of the Goal-Based Service Ontology (GSO), which is a fundamental component of the GSF, and discusses how the framework supports semantic service discovery and composition. GSO provides a set of primitives and relations between goals, tasks and services. These primitives allow a user to represent its goals, and a supporting platform to discover or compose services that fulfil them

Defining and Prototyping a Life-cycle for Dynamic Service Composition

Since the Internet has become a commodity in both wired and wireless environments, new applications and paradigms have emerged to explore this highly distributed and widespread system. One such paradigm is service-orientation, which enables the provision of software functionality as services, \ud allowing in this way the construction of distributed systems with loosely coupled parts. The Service-Oriented Architecture (SOA) provides a set of principles to create service-oriented systems, by defining how services can be \ud created, composed, published, discovered and invoked. In accordance with these principles, in this paper we address the challenge of performing dynamic service composition. The composition process and its associated tasks have to be precisely defined so that the different problems of dynamic service composition can be identified and tackled. To achieve this, this paper defines a life-cycle for dynamic service composition, which defines the required phases and stakeholders. Furthermore, we present our prototype in which the different phases of the dynamic service composition life-cycle are being implemented. This prototype is being used to experiment with and validate our initial ideas on dynamic service composition

Ecoeficiência agropecuária dos municípios brasileiros seguindo o censo agropecuário de 2017

Trabalho de Conclusão de Curso (graduação)—Universidade de Brasília, Faculdade de Economia, Administração, Contabilidade e Gestão de Políticas Públicas, Departamento de Administração, 2021.Este trabalho busca, a partir da aplicação dos modelos clássicos de Data Envelopment Analysis (DEA), CCR e BCC, encontrar as eficiências técnicas e de escala de todos os municípios brasileiros, seguindo os dados do Censo Agropecuário do IBGE de 2017. Serão delimitados outliers, utilizando resultados de supereficiência, seguindo o procedimento BG. O cálculo da eficiência terá variáveis ambientais, portanto se tratará de uma ecoeficiência. Com os resultados encontrados, se busca obter um mapa do Brasil, em que serão representados os municípios de acordo com seus escores de eficiência. Foi encontrado uma baixa eficiência global e alta eficiência de escala, o que define que a causa da ineficiência é a baixa eficiência técnica. Por conta do caráter de ecoeficiência, os municípios mais eficientes estão encontrados na região Norte, onde há legislações para o controle da preservação mais rigorosas.This work intends to calculate, based on the application os the classic Data Envelopment Analysis (DEA) models, CCR and BCC, the thecnical efficiency and scale efficiency from all the brazilian municipalities, based on the data collected from the Censo Agropecuário of IBGE 2017. There will be determined outliers, utilizing superefficiency results, following the BG procedure. To calculate the efficiencies, there are going to be used ambiental variables, so the results represents an eco-efficiency. After finding the results, the efficiency will be represented in a map, so that it’s possible to see the efficiency scores throughout the regions. The reults foud where a low global efficiency, but high scale efficiency, hence the inefficiency cause is a low technical efficiency. Due to the eco-efficiency character, the efficient municipalities are concentrated in the North region, where there is more strict legislation to control the preservation