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  1. 1

    Short-term electricity prices forecasting in a competitive market by a hybrid PSO-ANFIS approach

    Publicação
    por Pousinho, Hugo Miguel Inácio
    Outros Autores: Mendes, Victor; Catalão, João Paulo da Silva
    In this paper, a novel hybrid approach is proposed for electricity prices forecasting in a competitive market, considering a time horizon of 1 week. The proposed approach is based on the combination of particle swarm optimization and adaptive-network based fuzzy inference system. Results from a case study based on the electricity market of mainland Spain are presented. A thorough comparison is carried out, taking into account the results of previous publications, to demonstrate its effectiveness regarding forecasting accuracy and computation time. Finally, conclusions are duly drawn. (C) 2012 Elsevier Ltd. All rights reserved.
    2012 artigo Portugal acesso aberto
  2. 2

    Scheduling of a hydro producer considering head-dependency, price scenarios and risk-aversion

    Publicação
    por Pousinho, Hugo Miguel Inácio
    Outros Autores: Mendes, Victor; Catalão, João Paulo da Silva
    In this paper, a mixed-integer quadratic programming approach is proposed for the short-term hydro scheduling problem, considering head-dependency, discontinuous operating regions and discharge ramping constraints. As new contributions to earlier studies, market uncertainty is introduced in the model via price scenarios, and risk aversion is also incorporated by limiting the volatility of the expected profit through the conditional value-at-risk. Our approach has been applied successfully to solve a case Study based on one of the main Portuguese cascaded hydro systems, requiring a negligible computational time.
    2012 artigo Portugal acesso restrito
  3. 3

    Hydro energy systems management in Portugal: Profit-based evaluation of a mixed-integer nonlinear approach

    Publicação
    por Catalão, João Paulo da Silva
    Outros Autores: Pousinho, Hugo Miguel Inácio; Mendes, Victor
    In this paper, a novel mixed-integer nonlinear approach is proposed to solve the short-term hydro scheduling problem in the day-ahead electricity market, considering not only head-dependency, but also start/stop of units, discontinuous operating regions and discharge ramping constraints. Results from a case study based on one of the main Portuguese cascaded hydro energy systems are presented, showing that the proposedmixed-integer nonlinear approach is proficient. Conclusions are duly drawn. (C) 2010 Elsevier Ltd. All rights reserved.
    2011 artigo Portugal acesso aberto
  4. 4

    QSAR modeling of antitubercular activity of diverse organic compounds

    Publicação
    por Kovalishyn, Vasyl
    Outros Autores: Aires-de-Sousa, Joao; Ventura, Cristina; Elvas Leitao, Ruben; Martins, Filomena
    Tuberculosis (TB) is a worldwide infectious disease that has shown over time extremely high mortality levels. The urgent need to develop new antitubercular drugs is due to the increasing rate of appearance of multi-drug resistant strains to the commonly used drugs, and the longer durations of therapy and recovery, particularly in immuno-compromised patients. The major goal of the present study is the exploration of data from different families of compounds through the use of a variety of machine learning techniques so that robust QSAR-based models can be developed to further guide in the quest for new potent anti-TB compounds. Eight QSAR models were built using various types of descriptors (from ADRIANA.Code and Dragon software) with two publicly available structurally diverse data sets, including recent data deposited in PubChem. QSAR methodologies used Random Forests and Associative Neural Networks. Predictions for the external evaluation sets obtained accuracies in the range of 0.76-0.88 (for active/inactive classifications) and Q(2)=0.66-0.89 for regressions. Models developed in this study can be used to estimate the anti-TB activity of drug candidates at early stages of drug development (C) 2011 Elsevier B.V. All rights reserved.
    2011 artigo Portugal acesso aberto
  5. 5

    Nonlinear optimization method for short-term hydro scheduling considering head-dependency

    Publicação
    por Catalão, João Paulo da Silva
    Outros Autores: Mariano, S. J. P. S.; Mendes, Victor; Ferreira, L. A. F. M.
    This paper is on the problem of short-term hydro scheduling, particularly concerning head-dependent reservoirs under competitive environment. We propose a new nonlinear optimization method to consider hydroelectric power generation as a function of water discharge and also of the head. Head-dependency is considered on short-term hydro scheduling in order to obtain more realistic and feasible results. The proposed method has been applied successfully to solve a case study based on one of the main Portuguese cascaded hydro systems, providing a higher profit at a negligible additional computation time in comparison with a linear optimization method that ignores head-dependency.
    2010 artigo Portugal acesso aberto