On the Models Derived from Resource Efficacy Model.

Grey resource efficacy model is effective for describing the developing stage (rapid varying phase) of resource efficacy S curve. In order to further complement the model system, this paper deduces five derived models based on the original resource efficacy model proposed by Professor Deng. The properties of these derived models are then studied respectively. The results show that different models have different structures, contents, solutions and properties, implying the principal of non-uniqueness in grey system theory. [ABSTRACT FROM AUTHOR]