Browsing by Subject "Time series analysis"

Now showing 1 - 4 of 4
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    Transient dynamic analysis of dam-reservoir interaction by coupling DRBEM and FEM
    (2004) Küçükarslan S.; Coşkun S.B.
    In this paper, time domain dynamic analysis of dam-reservoir interaction is presented by coupling the dual reciprocity boundary element method in the infinite fluid domain and the finite element method in the solid domain. An efficient coupling procedure is formulated by using sub-structuring method. Sammerfeld's boundary condition for far end of the infinite domain is implemented. To verify the proposed scheme, numerical examples are carried out to compare with the available exact solutions and results of the finite-finite element coupling.
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    Comparative analysis of fuzzy inference systems for water consumption time series prediction
    (2009) Firat M.; Turan M.E.; Yurdusev M.A.
    Two types of fuzzy inference systems (FIS) are used for predicting municipal water consumption time series. The FISs used include an adaptive neuro-fuzzy inference system (ANFIS) and a Mamdani fuzzy inference systems (MFIS). The prediction models are constructed based on the combination of the antecedent values of water consumptions. The performance of ANFIS and MFIS models in training and testing phases are compared with the observations and the best fit model is identified according to the selected performance criteria. The results demonstrated that the ANFIS model is superior to MFIS models and can be successfully applied for prediction of water consumption time series. © 2009 Elsevier B.V. All rights reserved.
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    Comparative analysis of neural network techniques for predicting water consumption time series
    (2010) Firat M.; Turan M.E.; Yurdusev M.A.
    Monthly water consumption time series have been predicted using a series of Artificial Neural Network (ANN) techniques including Generalized Regression Neural Networks (GRNN), Cascade Correlation Neural Network (CCNN) and Feed Forward Neural Networks (FFNN). One hundred and eight data sets for the city of Izmir, Turkey are used for a number of ANN modeling exercises. Several ANN models depending on the combination of antecedent values of water consumption records are constructed and the best fit input structure is investigated. The performance of ANN models in training and testing stages are compared with the observed water consumption values to identify the best fit forecasting model based upon a number of selected performance criteria. © 2010 Elsevier B.V. All rights reserved.
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    Effects of phase shift on the heat transfer characteristics in pulsating mixed convection flow in a multiple vented cavity
    (Elsevier Inc., 2015) Selimefendigil F.; Öztop H.F.
    In the current study, numerical investigation of pulsating mixed convection in a multiple vented cavity with phase shift is carried out for the range of parameters; Richardson number (0.25. ≤. Ri. ≤. 4), phase shift (0. ≤. ϕ. ≤. π) and Strouhal number is fixed at 1. The governing equations are solved with a general purpose finite volume based solver. The effects of Ri number and phase shift parameters on the fluid flow and heat transfer characteristics are numerically studied. It is observed that the flow field and heat transfer enhancement are influenced by the variation of these parameters. Furthermore, recurrence plot analysis is applied for the analysis of the time series (spatial averaged Nusselt number along the vertical wall of the cavity) and for a combination of different parameters, the systems are identified using recurrence quantification analysis parameters including recurrence rate, laminarity, determinism, trapping time and entropy. © 2014 Elsevier Inc..