This class of subgraphs, known as segs, was introduced by Reed in 1961. 这类子图称为广义割集,它是由里德在1961年提出的。
Solar Energy Generating Systems ( SEGS) has been the world record holder for largest solar thermal project since its completion in1990. 自从1990年建成之后,加州南部的太阳能发电系统就一直是最大的太阳能热电工程。