RT Journal T1 A semi-supervised method based on tree kernel for relationship extraction A1 LIU Xiaoyong PB Journal of Shandong University(Engineering Science) FD 2015-04-20 YR 2015 JF Journal of Shandong University(Engineering Science) JO Journal of Shandong University(Engineering Science) VO 45 IS 2 SP 22 DO 10.6040/j.issn.1672-3961.1.2014.259 K1 relationship extraction;tree kernel;support vector machine;semi-supervised method;semantic variation LK {http://gxbwk.njournal.sdu.edu.cn/EN/article/article_1538.shtml}