Suspended load estimation using L1-fuzzy regression,L2-fuzzy regression and MARS-fuzzy regression models |
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| Authors: | Jalal Chachi Seyed Mahmoud Taheri Hojat Rezaee Pazhand |
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| Institution: | 1. Department of Mathematics, Statistics and Computer Sciences, Semnan University, Semnan, Iranjchachi@profs.semnan.ac.ir;3. Faculty of Engineering Sciences, College of Engineering, University of Tehran, Tehran 11365-4563, Iran;4. Maharab Geotechnical, Water Resources and Dam Consulting Engineers, Mashhad, Iran |
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| Abstract: | ABSTRACTThe problem of estimation of suspended load carried by a river is an important topic for many water resources projects. Conventional estimation methods are based on the assumption of exact observations. In practice, however, a major source of natural uncertainty is due to imprecise measurements and/or imprecise relationships between variables. In this paper, using the Multivariate Adaptive Regression Splines (MARS) technique, a novel fuzzy regression model for imprecise response and crisp explanatory variables is presented. The investigated fuzzy regression model is applied to forecast suspended load by discharge based on two real-world datasets. The accuracy of the proposed method is compared with two well-known parametric fuzzy regression models, namely, the fuzzy least-absolutes model and the fuzzy least-squares model. The comparison results reveal that the MARS-fuzzy regression model performs better than the other models in suspended load estimation for the particular datasets. This comparison is done based on four goodness-of-fit criteria: the criterion based on similarity measure, the criterion based on absolute errors and the two objective functions of the fuzzy least-absolutes model and the fuzzy least-squares model. The proposed model is general and can be used for modelling natural phenomena whose available observations are reported as imprecise rather than crisp. Editor D. Koutsoyiannis; Associate editor H. Aksoy |
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| Keywords: | discharge goodness-of-fit least-absolutes fuzzy regression least-squares fuzzy regression multivariate adaptive regression splines (MARS) suspended load |
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