  Based on the definition of generalized partially bent functions, using the
theory of linear transformation, the relationship among generalized partially
bent functions over ring Z N, generalized bent functions over ring Z N and
affine functions is discussed. When N is a prime number, it is proved that a
generalized partially bent function can be decomposed as the addition of a
generalized bent function and an affine function. The result obtained here
generalizes the main works concerning partially bent functions by Claud Carlet
in [1].
