System Division, Zhejiang Province Electric Power Test and Research Institute, Hangzhou, Zhejiang 310014, China
Copyright © 2010 Zhen-Hang Yang. 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 necessary and sufficient conditions for Schur geometrical convexity of the four-parameter means are given. This gives a unified treatment for Schur geometrical convexity of Stolarsky and Gini means.