32 research outputs found

    Electric load forecasting using a fuzzy ART&ARTMAP neural network

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    This work presents a neural network based on the ART architecture ( adaptive resonance theory), named fuzzy ART& ARTMAP neural network, applied to the electric load-forecasting problem. The neural networks based on the ARTarchitecture have two fundamental characteristics that are extremely important for the network performance ( stability and plasticity), which allow the implementation of continuous training. The fuzzy ART& ARTMAP neural network aims to reduce the imprecision of the forecasting results by a mechanism that separate the analog and binary data, processing them separately. Therefore, this represents a reduction on the processing time and improved quality of the results, when compared to the Back-Propagation neural network, and better to the classical forecasting techniques (ARIMA of Box and Jenkins methods). Finished the training, the fuzzy ART& ARTMAP neural network is capable to forecast electrical loads 24 h in advance. To validate the methodology, data from a Brazilian electric company is used. (C) 2004 Elsevier B.V. All rights reserved

    Electrical load forecasting formulation by a fast neural network

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    The objective of this work is to develop a methodology for electric load forecasting based on a neural network. Here, backpropagation algorithm is used with an adaptive process that based on fuzzy logic and using a decaying exponential function to avoid instability in the convergence process. This methodology results in fast training, when compared to the conventional formulation of backpropagation algorithm. The results are presented using data from a Brazilian Electric Company, and shows a very good performance for the proposal objective

    High rate of non-albicans candidemia in Brazilian tertiary care hospitals

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    In order to evaluate the epidemiology of candidemia in Brazil, we performed a prospective multicenter study conducted in six general hospitals from Sao Paulo and Rio de Janeiro. We enrolled a total of 145 candidemic patients (85 males) with a median age of 32 years. Non-albicans species accounted for 63% of all episodes and the species most frequently causing candidemia were C. albicans (37%), C. parapsilosis (25%), C. tropicalis (24%), C. rugosa (5%), and C. glabrata (4%). Systemic azoles were used before the onset of candidemia in only six patients. There were no differences in the coexisting exposures or underlying diseases associated with the species most frequently causing candidemia. The overall crude mortality rate was 50%. Nosocomial candidemias in our tertiary hospitals are caused predominantly by non-albicans species, which are rarely fluconazole resistant. This predominance of non-albicans species could not be related to the previous use of azoles. (C) 1999 Elsevier Science Inc.Univ Fed Sao Paulo, Escola Paulista Med, Dept Med,Div Infect Dis, Special Mycol Lab, BR-04023062 Sao Paulo, BrazilUniv Fed Rio de Janeiro, Univ Hosp, Dept Internal Med, Div Hematol, Rio De Janeiro, BrazilHosp & Maternidade Santa Marcelina, Sao Paulo, BrazilUniv Estadual Campinas, Dept Med, Div Infect Dis, BR-13081970 Campinas, SP, BrazilHosp Servidor Publ Estadual, Sao Paulo, BrazilUniv Estado Rio de Janeiro, Univ Hosp, Rio De Janeiro, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Dept Med,Div Infect Dis, Special Mycol Lab, BR-04023062 Sao Paulo, BrazilWeb of Scienc

    In situ bipolar Electroporation for localized cell loading with reporter dyes and investigating gap junctional coupling

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    Background: Therapy strategies for myelodysplastic syndromes (MDS) and juvenile myelomonocytic leukemia (JMML) vary considerably. Objective: To review the treatment of Brazilian children who were diagnosed with MDS or JMML in the past decade and reported to the Brazilian Cooperative Group on Pediatric Myelodysplastic syndromes (BCG-MDS-PED). Results: of 173 children reported to the BCG-MDS-PED from January 1997 to January 2003 with a suspected diagnosis of MDS or JMML, 91 had the diagnosis confirmed after central review of the bone marrow aspirate and biopsy. Information on previous treatments was available for 78 MDS/JMML patients. Treatment varied from different schedules of low-dose (14%) and standard-dose chemotherapy (50%), granulocyte-colony-stimulating factor (G-CSF 7%), interferon (5%), steroids (2%) and erythropoietin (2%) to allogeneic stem-cell transplantation (SCT) (14%). No survival advantage could be demonstrated based on Hasle's classification or based on treatment. Conclusion: This report reflects the current practice in treating Brazilian children with MDS/JMML without specific Cooperative Group guidelines. Treatment modalities were very heterogeneous. The strategies for implementing a national protocol should consider international guidelines and focus on local experience and available resources. (C) 2004 Elsevier Ltd. All rights reserved
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