  In the first part of the present work, the correction to photon emission rate
of an oscillating two-level atom in the presence of electromagnetic quantum
vacuum field has been investigated for two different configurations: (i) Atom
is trapped in the vicinity of a perfect conductor (ii) Atom is trapped between
two perfect conductors. In the second part, the correction to the decay rate of
an initially excited oscillating two-level atom due to the presence of a
perfect conducting surface is found.
