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Publicações

Publicações por Luis Lino Ferreira

2016

Improved Holistic Analysis for Fork-Join Distributed Real-Time Tasks supported by the FTT-SE Protocol

Autores
Garibay Martínez, R; Nelissen, G; Ferreira, LL; Pedreiras, P; Pinho, LM;

Publicação
IEEE Transactions on Industrial Informatics

Abstract
Modern distributed real-time embedded applications have high processing requirements associated with strict deadlines. For some applications, such constraints cannot be fulfilled by existing single-core embedded platforms. A solution is to parallelise the execution of the applications, by allowing networked nodes to distribute their workload to remote nodes with spare capacity. In that context, this paper presents a holistic timing analysis for fixedpriority fork-join Parallel/Distributed tasks (P/D tasks). Furthermore, we extend the holistic approach to consider the interaction between parallel threads and messages interchanged through a Flexible Time Triggered - Switched Ethernet (FTT-SE) network, and we show how the pessimism on the Worst-Case Response Time computation of such tasks can be reduced by considering the pipeline effect that occurs in such distributed systems. To evaluate the performance and correctness of the holistic model, this paper includes a numerical evaluation based on a real automotive application. The obtained results show that the proposed method is effective in distributing the load by different nodes, allowing a significant reduction of the worst-case response time of the tasks. Moreover, the paper also reports an implementation of the model on a Linux library, called Parallel/Distributed Real-Time, as well as the corresponding results obtained on a real testbed. The obtained results are in accordance with the predictions of the holistic timing analysis. © 2016 IEEE.

2016

Extending publish/subscribe mechanisms to SOA applications

Autores
Albano, M; Ferreira, LL; Sousa, J;

Publicação
2016 IEEE WORLD CONFERENCE ON FACTORY COMMUNICATION SYSTEMS (WFCS)

Abstract
The Arrowhead Framework is a European effort that aims to apply Service Oriented Architecture to the embedded systems' world. The Event Handler system is a component that supports the handling of events, and in that sense it enriches service-oriented applications with the capabilities of interacting via the publish/subscribe paradigm. In fact, the Event Handler system is in charge of the notification of events that occur in a given Arrowhead compliant installation, manages producers and consumers of events, allows filtering of messages, and manages historical data regarding events. This latter capability is performed either on local files, on a database, or through another component of the Arrowhead Framework - the Historian system. The net result of the integration of the Event Handler in an Arrowhead Framework simplifies and empowers the communication of its components, as it is demonstrated in the paper with two examples: the management of application faults, and the support to quality of service of orchestrated services.

2016

Lessons learned in building a middleware for smart grids

Autores
Macarulla, M; Albano, M; Ferreira, LL; Teixeira, C;

Publicação
Journal of Green Engineering

Abstract
Smart grids play an important role in the modernization and optimization of the existing electrical grid, to accomplish the current European Union Energy and Climate targets. Smart grids require distributed applications to manage the grid more efficiently. The performance of the distributed applications impacts on the communications delay time and on the timely interaction with the devices located in the users' Home Area Networks. This paper presents the results of the ENCOURAGE project related to the development of a software platform to support smart grids. The work presented in this paper assesses four different middleware configurations and analyses the results on the delay performance tests. The results show that the mean end-to-end delay is between 310 ms and 453 ms in proper conditions. In terms of operational costs, the optimal configuration enables managing houses with less than 0.25 Euros per month per house. This paper justifies the maturity of the technology to support smart grids, and the possibility to transfer the ENCOURAGE project results to the industry.

2016

Optimising maintenance: What are the expectations for Cyber Physical Systems

Autores
Jantunen, E; Zurutuza, U; Ferreira, LL; Varga, P;

Publicação
2016 3rd International Workshop on Emerging Ideas and Trends in Engineering of Cyber-Physical Systems, EITEC 2016

Abstract
The need for maintenance is based on the wear of components of machinery. If this need can be defined reliably beforehand so that no unpredicted failures take place then the maintenance actions can be carried out economically with minimum disturbance to production. There are two basic challenges in solving the above. First understanding the development of wear and failures, and second managing the measurement and diagnosis of such parameters that can reveal the development of wear. In principle the development of wear and failures can be predicted through monitoring time, load or wear as such. Monitoring time is not very efficient, as there are only limited numbers of components that suffer from aging which as such is result of chemical wear i.e. changes in the material. In most cases the loading of components influences their wear. In principle the loading can be stable or varying in nature. Of these two cases the varying load case is much more challenging than the stable one. The monitoring of wear can be done either directly e.g. optical methods or indirectly e.g. vibration. Monitoring actual wear is naturally the most reliable approach, but it often means that additional investments are needed. The paper discusses the above issues and what are the requirements that follow from these for optimising maintenance based of the use of Cyber Physical Systems. © 2016 IEEE.

2017

Application system design - Energy optimisation

Autores
Albano, M; Skou, A; Ferreira, LL; Le Guilly, T; Pedersen, PD; Pedersen, TB; Olsen, P; Šikšnys, L; Smid, R; Stluka, P; Le Pape, C; Desdouits, C; Castiñeira, R; Socorro, R; Isasa, I; Jokinen, J; Manero, L; Milo, A; Monge, J; Zabasta, A; Kondratjevs, K; Kunicina, N;

Publicação
IoT Automation: Arrowhead Framework

Abstract
Introduction In this chapter, we present a number of applications of the Arrowhead Framework with special attention to services related to awareness and optimisation of energy consumption. First, we present the notion of FlexOffers as a general mechanism for describing energy flexibility. FlexOffers can be aggregated into larger flexibility units to be used as an Arrowhead service in the virtual market of energy [1]. This is followed by two examples on how to exploit such a flexibility service in the energy management of heat pumps and a campus building. Then we present two examples on how to exploit renewable energy to provide elevator services. Next, two examples of context aware services are described - smart lighting and smart car heating, and finally it is described how the Arrowhead Framework can play a role in the optimisation of municipal service systems. In the final section, we indicate future work. © 2017 by Taylor & Francis Group, LLC.

2017

Application system and services: Design and implementation - A cookbook

Autores
Delsing, J; Albano, M; Ferreira, L; Blomstedt, F; Olofsson, P; Varga, P; Montori, F; Viola, F;

Publicação
IoT Automation: Arrowhead Framework

Abstract
Introduction In previous chapters local automation clouds and a SOA based architecture supporting the design and implementation of IoT based automation systems were discussed. This chapter is devoted to design and implementation of application services: •Design of an Arrowhead Framework system •Implementation of such a system and its services •Interoperability test 5.2 Application service design This section will discuss the design of an automation application system and associated services. For this purpose, we will make use of the simple control loop example addressing the level in a flotation tank. © 2017 by Taylor & Francis Group, LLC.

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