Online Active Learning with Drifted Data Streams Using Paired Ensemble Framework Ji-Cheng Shan, Wei-Ke Liu, Chen-Xi Chu, Chao-Fan Dai and Qing-Bao Liu ITM Web Conf., 12 (2017) 05016 Published online: 05 September 2017 DOI: 10.1051/itmconf/20171205016