Memory Property of Grey Accumulation Generation Sequence

Figure 3

The original AQI value and one-order accumulation value of three cities.

(a) The AQI in Beijing

(b) The 1-AGO of Beijing AQI

(c) The AQI in Handan

(d) The 1-AGO of Handan AQI

(e) The AQI in Xingtai

(f) The 1-AGO of Xingtai AQI