In the above paper [H. Kang et al., 2007], the author would like to make the following corrections. Due to a lack of knowledge of the common practice of professional publications, the author has included Rongyu Li, Xin Yang, and Tian Xiao as coauthors without their consent or knowledge. Hao Kang should be the sole author of the paper [H. Kang et al., 2007] and is responsible for all the contents. He apologizes to the other coauthors whose names should not be associated with the paper. Furthermore, the author wishes to apologize to the authors of [T.N. Ruckmongathan et al., 2006] for simply copying some portions of their paper into his own paper [H. Kang et al., 2007]. Although this was the author's first ever attempt to publish a technical paper and he did cite [T.N. Ruckmongathan et al., 2006] at the reference section of his own paper [H. Kang et al., 2007], he now realizes that copying a part of other authors' publications is not acceptable even though the intention was to give credit to the earlier work by other people. Therefore, the author sincerely apologizes for his mistake although it was not malicious by any means.