%0 Journal Article %T Graphs with <i>k</i>-Role Assignments %A Yana Liu %A Yongqiang Zhao %J Open Journal of Discrete Mathematics %P 177-184 %@ 2161-7643 %D 2017 %I Scientific Research Publishing %R 10.4236/ojdm.2017.73016 %X For a given graph G, a k-role assignment of G is a surjective function \"\" such that \"\", where N(x) and N(y) are the neighborhoods of x and y, respectively. Furthermore, as we limit the number of different roles in the neighborhood of an individual, we call r a restricted size k-role assignment. When the hausdorff distance between the sets of roles assigned to their neighbors is at most 1, we call r a k-threshold close role assignment. In this paper we study the graphs that have k-role assignments, restricted size k-role assignments and k-threshold close role assignments, respectively. By the end we discuss the maximal and minimal graphs which have k-role assignments. %K Neighborhood %K < %K i> %K k< %K /i> %K -Role Assignment %K Restricted Size k-Role Assignment %K < %K i> %K k< %K /i> %K -Threshold Close Role Assignment %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=77772