Department of Applied Mathematics, Pukyong National University, Busan 608-737, South Korea
Copyright © 2009 Nak Eun Cho and In Hwa Kim. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The purpose of the present paper is to derive some sufficient conditions for Carathéodory functions in the open unit disk. Our results include several interesting corollaries as special cases.