C. Badea, K-FUNCTIONALS AND MODULI OF SMOOTHNESS OF FUNCTIONS DEFINED ON COMPACT METRIC-SPACES, Computers & mathematics with applications, 30(3-6), 1995, pp. 23-31
One proves that Peetre's K-functional for the couple (C(X),Lip(X)) and
the first order modulus of continuity are equivalent for every Peano
continuum. Some inequalities for the first order modulus of continuity
and the mixed modulus of smoothness of functions defined on some comp
act metric spaces are proved and some possible applications are indica
ted.