Research On The Improvement Of Grey Forecast Model GM(1.1)&GM(2.1)

Gray system theory is a new method to research on the non-determinism with little data and information. Studying on the non-determinism system that has characteristics of some information having known while others remain unknown, gray system theory extracts valuable information to describe and monitor the operation behaviors and evolution tendency of system correctly and effectively through the production and development of some information having known. And gray forecast finds and grasps system tendency to make scientific quantitative forecast of system's future condition by processing initial data and establishing gray model.The thesis researches on grey forecast model and its improvement.Firstly it introduces basic concepts & characteristics of forecast theory and sequence operator & the production of grey sequence, then makes systematic elaboration on basic modeling theory of grey forecast model, including smoothness condition of grey forecast modeling, grey index rule of AGO and cushion operator etc. Secondly from reasoning hermeticness of differtial perspectives, the thesis adjusts initial value model of GM(1.1)&GM(2.1).At last based on the study of whiting equation shadow equation and time response sequence of formerly grey forecast model GM(1.1)&GM(2.1), the paper deeply researches and discusses its modeling mechanism and methods, analyses its flaws, and develops the forecast model in the selection of initial value then enhances the forecast precision.In addition the paper proofs the validity of new model through examples.