Generalized accumulated GM(1,1) cosine model and its application

Based on the generalized accumulated generating operation, in this paper GAGM(1,1) cosine model is proposed to improve the classical GM(1,1) cosine model. The GAGM(1,1) cosine model can fit in many kind of periodic sequences, such as non-equidistant periodic sequences and non-equidistant periodic sequences with jump point or with multi-stage. Also GAGM(1,1) cosine model's parameter space and solving process are discussed in details. At last the proposed model is used to predict oil production. The results showed that the precision of GAGM(1,1) cosine model is higher than GM(1,1) model and confirmed that the GAGM(1,1) cosine model has important theoretic and practical significance.