...Xinyu Zhang; Jun Zhang; Siqi Dong; Ruiqin Feng Purpose Accurate forecasting of Europe’s battery electric vehicle (BEV) market is crucial for trend analysis and policy formulation. This study aims to propose an innovative discrete grey model specifically designed for predicting BEV sales in Europe...

... (Gou et al., 2022). For example, to consider the nonlinear effect, Ding and Xu et al. designed a novel discrete grey model by introducing grey power indexes into the model structure (Ding et al., 2020). Given the seasonal characteristics of the seasonal wind power generation...

... of the conventional discrete grey model (DGM), we advance a novel DGRM, and the model's prediction effect is evaluated by two numerical examples and an application case and compared with that of other conventional grey models. Findings The average relative simulation error of DGRM(1,1) does not change...

... of quality level (often depicted by qualification rate) can be obtained. This paper also aims to introduce a new prediction model, namely discrete grey model (DGM), to forecast the changing trend of quality cost. Design/methodology/approach This paper comes to the conclusion by means of mathematical...

... ) . Grey systems modelling and prediction Grey forecasting Original form Even form Even grey model (EGM), Origin Shadow equation Model GM(1, 1) Original difference (ODGM) Even difference (EDGM) Discrete grey model Grey disaster forecasting The time response formula of original difference...

... – The definitions of four basic models of GM(1, 1), such as Even Grey Model (EGM), Original Difference Grey Model (ODGM), Even Difference Grey Model (EDGM) and Discrete Grey Model (DGM), are put forward. The properties and characteristics of different models are studied and their equivalence are proved...

.... Design/methodology/approach After proving that the three principles of smooth sequence are not a sufficient condition for the judgement of sequence smoothness, judgement rules for sequence smoothness based on smoothness efficiency is introduced. Based on the non‐homogenous discrete grey model (NDGM...