TY - JOUR ID - Zwierzchowski2004 LB - Zwierzchowski2004 AU - Zwierzchowski, Maciej TI - Domination parameters of a graph with added vertex ST - Domination parameters of a graph with added vertex JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2004 VL - 24 IS - 2 SP - 231 EP - 234 DO - http://dx.doi.org/10.7494/OpMath.2004.24.2.231 UR - http://dx.doi.org/10.7494/OpMath.2004.24.2.231 AB - Let \(G=(V,E)\) be a graph. A subset \(D\subseteq V\) is a total dominating set of \(G\) if for every vertex \(y\in V\) there is a vertex \(x\in D\) with \(xy\in E\). A subset \(D\subseteq V\) is a strong dominating set of \(G\) if for every vertex \(y\in V-D\) there is a vertex \(x\in D\) with \(xy\in E\) and \(\deg _{G}(x)\geq\deg _{G}(y)\). The total domination number \(\gamma _{t}(G)\) (the strong domination number \(\gamma_{S}(G)\)) is defined as the minimum cardinality of a total dominating set (a strong dominating set) of \(G\). The concept of total domination was first defined by Cockayne, Dawes and Hedetniemi in 1980 [Cockayne E. J., Dawes R. M., Hedetniemi S. T.: Total domination in graphs. Networks 10 (1980), 211–219], while the strong domination was introduced by Sampathkumar and Pushpa Latha in 1996 [Pushpa Latha L., Sampathkumar E.: Strong weak domination and domination balance in a graph. Discrete Mathematics 161 (1996), 235–242]. By a subdivision of an edge \(uv\in E\) we mean removing edge \(uv\), adding a new vertex \(x\), and adding edges \(ux\) and \(vx\). A graph obtained from \(G\) by subdivision an edge \(uv\in E\) is denoted by \(G\oplus u_{x}v_{x}\). The behaviour of the total domination number and the strong domination number of a graph \(G\oplus u_{x}v_{x}\) is developed. KW - the total domination number KW - the strong domination number KW - subdivision SN - 1232-9274 ER -