emission of vehicles throughout a city[C]// The 20th ACM SIGKDD International Conference> [4] WU H H, CHENG J, HUANG S L, et al. Path problems in temporal graphs[C]// The VLDB Endowment, September 1-5, Hangzhou, China. New York: ACM Press, 2014: 721-732.
[5] HU X Y, YUAN M X, YAO J G, et al. Differential privacy in telco big data platform[C]//The 41st International Conference on Very Large Data Bases, August 31-September 4, Hawaii, USA. [S.l.:s.n.], 2015: 1692-1703.