1. Crossover phenomenon in vehicle emissions with DFA Wei Pan College of Physical Science and Technology, Guangxi University, China. August 13, 2013

2. Introduction Data collection of vehicle emission Detrended Fluctuation Analysis (DFA) Crossover Phenomenon in vehicle emission Notes

3. Introduction http://auto.people.com.cn/GB/25959/98358/8362/11367000.html Why so stuck! The problem in the traffic flow:

4. The problem behind the traffic flow: gasoline oxygen http://sichuan.sina.com/news/sc-all/2011-06-04/259-43291.html Vehicle emissions

5. Data collection Place ： Nathan Road, Mong Kok, Hong Kong Time : Rush hours ( 6:59:25~9:01:56 in the morning 16:52:31~18:16:12 in the afternoon ) Instrument : TSI model 982 Target : CO and CO 2 Cooperate with the City University of Hong Kong

6. Sequence of concentration for carbon emission

7. Normalized distributions of concentrations

8. DFA Detrended fluctuation analysis (DFA), first proposed by Peng et al. in 1994 [Phys. Rev. E 49, 1685–1689] And now it becomes a scaling analysis method for detection of long-range correlations embedded in data sequence.

9. whereis the length of the signal. Then divide the integrated signal into boxes of equal lengthand fit them by using a polynomial function. For a given box size, Integrate the time series

10. For different scales (box sizes ), we get is long-rang anticorrelation is long-rang correlation is no correlation

11. DFA fluctuation functionversus the scalein log-log plots Crossover phenomenon

12. Statistical analysis suggests that the major concentration distributions of carbon emission have little change. A crossover phenomenon has been found, which verifies the long-term dependence of carbon emission from vehicles. Notes

13. Ritz, B., Yu F. 1999. “The Effect of Ambient Carbon Monoxide on Low Birth Weight among Children Born in Southern California between 1989 and 1993,” Environmental Health Perspectives, 107(1):17-25. Peng, C. K., Buldyrev, S. V., Havlin, S., Simons, M., Stanley, H. E. and Goldberger, A.L. 1994. “Mosaic Organization of DNA Nucleotides,” Phys. Rev. E, 49(2):1685-1689. K. Hu, P. Ch. Ivanov, Z. Chen, P. Carpena and H. E. Stanley. 2001. “Effect of Trends on Detrended Fluctuation Analysis.” Phys. Rev. E, 64(1):011114(19). Sprott, J. C. 2004. “Chaos and Time-Series Analysis,” Oxford University Press, pp. 218-219. N. K. Das, R. K. Bhandari, P. Sen and B. Sinha. 2009. “Scaling and Crossover Phenomena in Anomalous Helium Sequence,”arXiv:0906.0832.arXiv:0906.0832References