title: An expert system with radial basis function neural network based on decision trees for predicting sediment transport in sewers.
abstract: In this study, an expert system with a radial basis function neural network (RBF-NN) based on decision trees (DT) is designed to predict sediment transport in sewer pipes at the limit of deposition. First, sensitivity analysis is carried out to investigate the effect of each parameter on predicting the densimetric Froude number (Fr). The results indicate that utilizing the ratio of the median particle diameter to pipe diameter (d/D), ratio of median particle diameter to hydraulic radius (d/R) and volumetric sediment concentration (C(V)) as the input combination leads to the best Fr prediction. Subsequently, the new hybrid DT-RBF method is presented. The results of DT-RBF are compared with RBF and RBF-particle swarm optimization (PSO), which uses PSO for RBF training. It appears that DT-RBF is more accurate (R(2) = 0.934, MARE = 0.103, RMSE = 0.527, SI = 0.13, BIAS = -0.071) than the two other RBF methods. Moreover, the proposed DT-RBF model offers explicit expressions for use by practicing engineers.
authors.affiliation: Department of Civil Engineering, Razi University, Kermanshah, Iran and Water and Wastewater Research Center, Razi University, Kermanshah, Iran E-mail: bonakdari@yahoo.com.
authors.forename: Isa
authors.initials: I
authors.lastname: Ebtehaj
authors.affiliation: Department of Civil Engineering, Razi University, Kermanshah, Iran and Water and Wastewater Research Center, Razi University, Kermanshah, Iran E-mail: bonakdari@yahoo.com.
authors.forename: Hossein
authors.initials: H
authors.lastname: Bonakdari
authors.affiliation: Department of Civil Engineering, Razi University, Kermanshah, Iran and Water and Wastewater Research Center, Razi University, Kermanshah, Iran E-mail: bonakdari@yahoo.com.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Zaji
mesh_terms: D003663:Decision Trees; D005103:Expert Systems; D007700:Kinetics; D008962:Models, Theoretical; D016571:Neural Networks, Computer; D012722:Sewage / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical