functional => function

has been researched => 



The survey shown in Introduction is poor. For example, the author wrote like, the works in 1987 and 1995 are continued in 2006 and 2007. But the duration between these two periods seems too long, if not any important research had not been done.

In addition to a poor expression in English, poor organization of the paper prevent readers of this paper from understanding the content. For example, the author should explain cleary at the very begining of the paper, what is "clipping" which plays the most important role in this paper. 

It might be an interestiong research work but author completely failed to show that.