“…The GC method based on CTWF can be described as follows [5], [7], [26]: first, assume that there are a set of m objects, a set of n criteria, and a set of s grey classes; according to the sample value x ij (i=1, 2 ,…, m; j=1, 2, …, n). Then, the steps of the GC method based on CTWF can be developed as follows:…”