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Publications

2017

Ensemble learning for data stream analysis: A survey

Authors
Krawczyk, B; Minku, LL; Gama, J; Stefanowski, J; Wozniak, M;

Publication
INFORMATION FUSION

Abstract
In many applications of information systems learning algorithms have to act in dynamic environments where data are collected in the form of transient data streams. Compared to static data mining, processing streams imposes new computational requirements for algorithms to incrementally process incoming examples while using limited memory and time. Furthermore, due to the non-stationary characteristics of streaming data, prediction models are often also required to adapt to concept drifts. Out of several new proposed stream algorithms, ensembles play an important role, in particular for 'non-stationary environments. This paper surveys research on ensembles for data stream classification as well as regression tasks. Besides presenting a comprehensive spectrum of ensemble approaches for data streams, we also discuss advanced learning concepts such as imbalanced data streams, novelty detection, active and semi supervised learning, complex data representations and structured outputs. The paper concludes with a discussion of open research problems and lines of future research. Published by Elsevier B.V.

2017

Simulation of the Iberian Electricity Market Using an Agent Based Model and Considering Hydro Stations

Authors
Sousa, JC; Saraiva, JT;

Publication
2017 14TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET (EEM 17)

Abstract
In the last decades power systems witnessed the implementation of an organizational and operational restructuring that lead to the introduction of competitive mechanisms in some activities of the value chain. This is the case of generation and retailing with the development of wholesale and retail markets. These developments together with a renewed emphasis on the adoption of more sustainable solutions while maintaining adequate security of supply levels contributed to increase the interest of generation companies for models enabling the optimization of the use of generation assets or for models and tools to help them to prepare and test bidding strategies to the day-ahead markets. Having in mind the increased complexity of the operation of power systems, Agent-Based Models, ABM, are been used to complement the traditional optimization and equilibrium models, taking advantage of the interaction between agents acting in a simulation environment. In this scope, this paper describes an ABM model that uses Q-learning to provide knowledge for the agents to behave in an optimal way. This model is designed to mimic the main features of the common electricity market between Portugal and Spain, the MIBEL. Apart from describing the developed model, this paper also includes preliminary results from its application to the MIBEL case.

2017

Entrepreneurial tourism: The creation of business opportunities in the ADRIMAG region, Portugal

Authors
Moreira, AC;

Publication
Entrepreneurship: Concepts, Methodologies, Tools, and Applications

Abstract
The chapter presents an entrepreneurial perspective to rural tourism. It is based on the utilization of endogenous resources that exist within a rural region, and leads to a group of business opportunities related to tourism, craftwork, and agriculture, which are taken into account to define the strategic objectives for the ADRIMAG region. The chapter follows a qualitative approach to business opportunities. Through our analysis, it was possible to create, in a simple manner, a group of business opportunities based on the endogenous resources of the region. With this study, we expect to bring forth an entrepreneurial perspective that will sustainably foster tourism development within rural regions, but with high potential for tourism attraction.

2017

Toward Industry 4.0: Efficient and Sustainable Manufacturing Leveraging MAESTRI Total Efficiency Framework

Authors
Ferrera, E; Rossini, R; Baptista, AJ; Evans, S; Hovest, GG; Holgado, M; Lezak, E; Lourenco, EJ; Masluszczak, Z; Schneider, A; Silva, EJ; Werner Kytola, O; Estrela, MA;

Publication
SUSTAINABLE DESIGN AND MANUFACTURING 2017

Abstract
This paper presents an overview of the work under development within MAESTRI EU-funded collaborative project. The MAESTRI Total Efficiency Framework (MTEF) aims to advance the sustainability of manufacturing and process industries by providing a management system in the form of a flexible and scalable platform and methodology. The MTEF is based on four pillars: (a) an effective management system targeted at process continuous improvement; (b) Efficiency assessment tools to support improvements, optimisation strategies and decision support; (c) Industrial Symbiosis paradigm to gain value from waste and energy exchange; (d) an Internet-of-Things infrastructure to support easy integration and data exchange among shop-floor, business systems and tools.

2017

User-Centered Design

Authors
Doroftei, D; Cubber, GD; Wagemans, R; Matos, A; Silva, E; Lobo, V; Cardoso, G; Chintamani, K; Govindaraj, S; Gancet, J; Serrano, D;

Publication
Search and Rescue Robotics - From Theory to Practice

Abstract

2017

Performance improvement of a buck converter using Kalman filtering

Authors
Gora, W; Duarte, C; Costa, P; Pereira, A;

Publication
International Journal of Power Electronics

Abstract

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