Let G be a graph with vertex set V and no isolated vertices. A subset \(S \subseteq V\) is a semipaired dominating set of G if every vertex in \(V {\setminus } S\) is adjacent to a vertex in S and S can be partitioned into two element subsets such that the vertices in each subset are at most distance two apart. The semipaired domination number \(\gamma _\mathrm{pr2}(G)\) is the minimum cardinality of a semipaired dominating set of G. We show that if G is a connected graph of order n with minimum degree at least 2, then \(\gamma _\mathrm{pr2}(G) \le \frac{1}{2}(n+1)\). Further, we show that if \(n \not \equiv 3 \, (\mathrm{mod}\, 4)\), then \(\gamma _\mathrm{pr2}(G) \le \frac{1}{2}n\), and we show that for every value of \(n \equiv 3 \, (\mathrm{mod}\, 4)\), there exists a connected graph G of order n with minimum degree at least 2 satisfying \(\gamma _\mathrm{pr2}(G) = \frac{1}{2}(n+1)\). As a consequence of this result, we prove that every graph G of order n with minimum degree at least 3 satisfies \(\gamma _\mathrm{pr2}(G) \le \frac{1}{2}n\).

令G为顶点集为V且没有孤立顶点的图。一个子集\（S \ subseteq V \）是一个semipaired支配集ģ如果在每个顶点\（V {\ setminus}Š\）相邻于一个顶点小号和小号可以划分为两个元件的子集，使得所述每个子集中的顶点最多相距两个距离。所述semipaired控制数\（\伽马_ \ mathrm {PR2}（G）\）是一个semipaired支配集的最小基数ģ。我们证明，如果G是阶数为n且最小度至少为2的连通图 ，则\（\ gamma _ \ mathrm {pr2}（G）\ le \ frac {1} {2}（n + 1）\）。此外，我们证明如果\（n \ not \ equiv 3 \，（\ mathrm {mod} \ ,, 4）\），则\（\ gamma _ \ mathrm {pr2}（G）\ le \ frac {1} {2} n \），我们证明对于\（n \ equiv 3 \，（\ mathrm {mod} \，4）\）的每个值，存在一个阶数为n的连通图G，其最小度至少为2满足\（\ gamma _ \ mathrm {pr2}（G）= \ frac {1} {2}（n + 1）\）。作为该结果的结果，我们证明最小阶数为n的每个n阶 图G至少满足\（\ gamma _ \ mathrm {pr2}（G）\ le \ frac {1} {2} n \）。