  We give a microscopic explanation for the recently observed equivalence among
thermodynamics of supergravity solutions for Dp-branes with or without NS
B-field and for D(p-2)-branes with vanishing B-field and two delocalized
transverse directions by showing that these D-brane configurations are related
to one another through T-duality transformations. This result also gives an
evidence for the equivalence among the noncommutative and the ordinary
Yang-Mills theories corresponding to the decoupling limits of the worldvolume
theories of such D-brane configurations.
