Open Access Open Access  Restricted Access Subscription or Fee Access

Combination Grey Model of Sewage Quantity Forecasting

Fang He, Tao Tao, Guosheng Lu

Abstract


Based on the grey forecasting theory, this paper discussed a modeling process used in forecasting sewage quantity. The combination grey model is constructed based on the residual grey forecasting model and new information and equal dimensional grey forecasting model. The sewage quantity of Rongchang County was forecasted with the basic grey model, the residual modification GM?1, 1?model, the improved new information and equal dimensional grey model and combination grey model. As for wastewater quantity of 2012, the improved models attain the lower residual of only 0.4% and -0.7%. As compare to the combination grey model, the lowest residual is only -0.05%. The results showed that forecasting sewage quantity with grey theory is simple and practical. The combination grey model greatly enhanced the forecasting precision and can be the tool of forecasting the long-medium sewage quantity.

Keywords


combination grey model, forecasting, new information and equal dimensional grey model, residual modification grey model.

Full Text:

PDF


Disclaimer/Regarding indexing issue:

We have provided the online access of all issues and papers to the indexing agencies (as given on journal web site). It’s depend on indexing agencies when, how and what manner they can index or not. Hence, we like to inform that on the basis of earlier indexing, we can’t predict the today or future indexing policy of third party (i.e. indexing agencies) as they have right to discontinue any journal at any time without prior information to the journal. So, please neither sends any question nor expects any answer from us on the behalf of third party i.e. indexing agencies.Hence, we will not issue any certificate or letter for indexing issue. Our role is just to provide the online access to them. So we do properly this and one can visit indexing agencies website to get the authentic information.