Longfei Shangguan Zheng Yang 0002 Zimu Zhou Xiaolong Zheng 0002 Chenshu Wu Yunhao Liu 0001 CrossNavi: enabling real-time crossroad navigation for the blind with commodity phones. 787-798 2014 UbiComp https://doi.org/10.1145/2632048.2632083 conf/huc/2014 db/conf/huc/ubicomp2014.html#ShangguanYZZWL14