“…The first is the problem of activity recognition itself (Blanke and Schiele, 2010; Calatroni, Roggen and Tröster, 2011; Chieu, Lee and Kaelbling, 2006; Hachiya, Sugiyama and Ueda, 2012; Krishnan, Lade and Panchanathan, 2010; Kurz, Hölzl, Ferscha, Calatroni, Roggen and Tröster, 2011; Roggen, Frster, Calatroni and Trster, 2011; Venkatesan, Krishnan and Panchanathan, 2010; Zhao, Chen, Liu and Liu, 2010; Zhao, Chen, Liu, Shen and Liu, 2011), and the second is the problem of user localization, which can then be used to increase the accuracy of the activity recognition algorithm (Pan, Tsang, Kwok and Yang, 2011; Pan, Kwok, Yang and Pan, 2007; Pan, Shen, Yang and Kwok, 2008; Pan, Zheng, Yang and Hu, 2008; Zheng, Pan, Yang and Pan, 2008). Both problems present interesting challenges for transfer learning.…”