A Nonlinear Grey Bernoulli Model with Conformable Fractional-Order Accumulation and Its Application to the Gross Regional Product in the Cheng-Yu Area

This study considers a nonlinear grey Bernoulli forecasting model with conformable fractionalorder accumulation, abbreviated as CFNGBM(1, 1, λ), to study the gross regional product in the ChengYu area. The new model contains three nonlinear parameters, the power exponent γ, the conformable fractional-order α and the background value λ, which increase the adjustability and flexibility of the CFNGBM(1, 1, λ) model. Nonlinear parameters are determined by the moth flame optimization algorithm, which minimizes the mean absolute prediction percentage error. The CFNGBM(1, 1, λ) model is applied to the gross regional product of 16 cities in the Cheng-Yu area, which are Chongqing, Chengdu,Mianyang, Leshan, Zigong, Deyang, Meishan, Luzhou, Suining, Neijiang, Nanchong, Guang’an, Yibin,Ya’an, Dazhou and Ziyang. With data from 2013 to 2021, several grey models are established and results show that the new model has higher accuracy in most cases.