Let be a graph with vertex set and edge set . A labeling of a graph is said to be edge-friendly if , where . An edge-friendly labeling induces a partial vertex labeling defined by if the edges incident to are labeled more than . Similarly, if the edges incident to are labeled more than . is not defined if the edges incident to are labeled and equally. The edge-balance index set of the graph , , is defined as , where .
An -wheel is a graph consisting of cycles, with each vertex of the cycles connected to one central hub vertex. The edge-balance index sets of -wheels are presented.