extremal skew energy of digraphs with no even cycles

let $d$ be a digraph with skew-adjacency matrix $s(d)$. then the skew energyof $d$ is defined to be the sum of the norms of all eigenvalues of $s(d)$. denote by$mathcal{o}_n$ the class of digraphs on order $n$ with no even cycles, and by$mathcal{o}_{n,m}$ the class of digraphs in $mathcal{o}_n$ with $m$ arcs.in this paper, we first give the minimal skew energy digraphs in$mathcal{o}_n$ and $mathcal{o}_{n,m}$ with $n-1leq mleqfrac{3}{2}(n-1)$. then we determine the maximal skew energy digraphs in$mathcal{o}_{n,n}$ and $mathcal{o}_{n,n+1}$, in the latter case assumingthat $n$ is even.