Acta mathematica scientia,Series B ›› 2011, Vol. 31 ›› Issue (3): 1103-1112.doi: 10.1016/S0252-9602(11)60301-9

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THE SCHUR CONVEXITY OF GINI MEAN VALUES IN THE SENSE OF HARMONIC MEAN

 XIA Wei-Feng, CHU Yu-Ming   

  1. School of Teacher Education, Huzhou Teachers College, Huzhou 313000, China; Department of Mathematics, Huzhou Teachers College, Huzhou 313000, China
  • Received:2008-11-10 Revised:2009-11-25 Online:2011-05-20 Published:2011-05-20
  • Supported by:

    Supported by the  NSFC (11071069), the NSF of Zhejiang Province (D7080080 and Y7080185), and the Innovation Team Foundation of the Department of Education of Zhejiang Province (T200924).

Abstract:

We prove that the Gini mean values S(a, b; x, y) are Schur harmonic convex with respect to (x, y)∈ (0, ∞)×(0,∞) if and only if (a, b)∈{(a,b):a≥0, ab,a+b+1≥0}∪{(a, b):b≥0, ba, a+b+1≥0} and Schur harmonic concave with respect to (x, y)∈(0, ∞)×(0, ∞) if and only if (a, b)∈{(a, b):a≤0, b≤0, a+b+1≤0}.

Key words: Gini mean values, Schur convex, Schur harmonic convex

CLC Number: 

  • 26B25
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