Document Type : Research Paper

Abstract

The objective of this research was the prediction of head rice yield (HRY) in fixed bed dryer by using artificial neural network approach. Several parameters affect on operation of fixed bed dryers that were considered as input variables for artificial neural network. These variables were: air relative humidity, air temperature, inlet air velocity, bed depth, initial moisture content, final moisture content and inlet air temperature. In total, 375 drying experiments were accomplished for creating of training and testing patterns by a laboratory dryer. Samples were separated from various depths of dryer and then dehulling and polishing operations were done by laboratory apparatues. HRY was measured for all the depths and average of them was considered as HRY for each experiment. Feed forward neural network and cascade forward neural network with Levenberg-Marquardt and Bayesians regulation back propagation algorithm were used for training of presented patterns. Results showed that the feed forward back propagation algorithm with topology of 7-7-7-1 and Levenberg-Marquardt training algorithm and similar activation functions for all of the layers (Sigmoid Tangent) predicted the HRY with coefficient of determination 0.9655 and mean absolute error 0.019 at different conditions of fixed bed paddy drying method. Results showed that the input air temperature and final moisture content had the strongest effect on HRY.

Keywords

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