  In this paper, we extend the reduced-basis methods developed earlier for wave
equations to goal-oriented wave equations with affine parameter dependence. The
essential new ingredient is the dual (or adjoint) problem and the use of its
solution in a sampling procedure to pick up "goal-orientedly" parameter
samples. First, we introduce the reduced-basis recipe --- Galerkin projection
onto a space $Y_N$ spanned by the reduced basis functions which are constructed
from the solutions of the governing partial differential equation at several
selected points in parameter space. Second, we propose a new "goal-oriented"
Proper Orthogonal Decomposition (POD)--Greedy sampling procedure to construct
these associated basis functions. Third, based on the assumption of affine
parameter dependence, we use the offline-online computational procedures
developed earlier to split the computational procedure into offline and online
stages. We verify the proposed computational procedure by applying it to a
three-dimensional simulation dental implant problem. The good numerical results
show that our proposed procedure performs better than the standard POD--Greedy
procedure in terms of the accuracy of output functionals.
