Miao Zhang Jianping Wu Chuang Lin Ke Xu Rethink the tradeoff between proportional controller and PI controller. 57-62 http://csdl.computer.org/comp/proceedings/iscc/2002/1671/00/16710057abs.htm 2002 conf/iscc/2002 ISCC db/conf/iscc/iscc2002.html#ZhangWLX02