...Xinhai Kong; Peng Zhang; Xin Ma Purpose The purpose of this paper is to improve the GM(1, 1) model based on concave sequences. Design/methodology/approach First, the restored sequence of the GM(1, 1) model is proved to be convex, and the residual characters of the GM(1, 1) model for concave...

... Publishing Limited Licensed re-use rights only Forecast GM(1 1) model Cotton spider mites Grey-BP neural network model Grey-Markov model Xinjiang is an important high-quality cotton production area in China and produces about 60 per cent of the country’s total cotton yield. However...

... (5) is non‐continuous and it is difficult to use traditional nonlinear optimization methods to solve it. In this paper, an improved AFSA is proposed to solve equation (5). © Emerald Group Publishing Limited 2012 Grey systems Forecasting Optimization techniques GM(1 1) model...