We discuss in this paper a method of finding skyline or non-dominated points
in a set $P$ of $n_P$ points with respect to a set $S$ of $n_S$ sites. A point
$p_i \in P$ is non-dominated if and only if for each $p_j \in P$, $j \not= i$,
there exists at least one point $s \in S$ that is closer to $p_i$ than $p_j$.
We reduce this problem of determining non-dominated points to the problem of
finding sites that have non-empty cells in an additive Voronoi diagram with a
convex distance function. The weights of the additive Voronoi diagram are
derived from the co-ordinates of the points of $P$ and the convex distance
function is derived from $S$. In the 2-dimensional plane, this reduction gives
a $O((n_S + n_P)\log n_S + n_P \log n_P)$-time randomized incremental algorithm
to find the non-dominated points.