GM (1, 1) Cosine Model and Its Application

In this paper GM(1, 1) cosine model was put forward for the periodic sequences existing widely. We solved the model and analyzed its properties. At the same time the paper studies GM(1, 1) cosine model´s parameter space. GM(1, 1) cosine model not only has the properties of exponential curve, but can reflect the periodicity of the sequences. It is the generalization of GM(1, 1) model. An example showed that the precision of GM(1, 1) cosine model is higher than GM(1, 1) model for the periodic sequences. So the model has important theoretic and practical significance.