Modified grey model for estimating traffic tunnel air quality |
| |
Authors: | Lee Cheng-Chung Wan Terng-Jou Kuo Chao-Yin Chung Chung-Yi |
| |
Institution: | (1) Graduate School of Engineering Science and Technology, National Yunlin University of Science and Technology, Douliou, Yunlin, Taiwan;(2) Institute of Safety Health and Environmental Engineering, National Yunlin University of Science and Technology, No. 123, Section 3, University Road, Douliou, Yunlin, 640, Taiwan;(3) Department of Environmental Engineering and Science, Tajen University, 20, Weishin Road, Yanpu Shiang, Pingtung, 907, Taiwan |
| |
Abstract: | This study compared three forecasting models based on the mean absolute percentage errors (MAPE) of their accuracy in forecasting
air pollution in a traffic tunnel: the Grey model (GM), the combination model used four sample point and five sample point
prediction with GM (1,1)(GM(1,1)4 + 5), and the modified grey model (MGM). An MGM was combined using the four points of the original sequence using the original
grey prediction GM (1,1) for short-term forecasting. The proposed method cannot only enhance the prediction accuracy of the
original grey model, but can also solve the jump data forecasting problem something for which the original grey model is inappropriate.
The MAPE was applied to the models, and the MGM found the proposed method to be simple and efficient. The MAPE of MGM, calculated
over 3 h of forecasts, were as follows: 10.12 (Upwind), 10.07 (Middle) and 7.68 (Downwind) for CO; 10.79 (Upwind), 6.05 (Middle)
and 5.98 (Downwind) for NO
x
, and 11.67 (Upwind), 7.32 (Middle) and 4.56 (Downwind) for NMHC. The MGM model results reveal that the combined forecasts
can significantly decrease the overall forecasting error. Results of this demonstrate that MGM can accurately forecast air
pollution in the Kaohsiung Chung–Cheng Tunnel. |
| |
Keywords: | Air quality Ordinary Least Squares (OLS) Modified Grey Model (MGM) Grey Model (GM(1 1)4 + 5) Traffic tunnel |
本文献已被 PubMed SpringerLink 等数据库收录! |
|