الفهرس | Only 14 pages are availabe for public view |
Abstract In this thesis we are concerned with a very important topic in graph theory, which is graph labeling. We study seven labelings of graphs, combination labeling, divisor labeling, divisor cordial labeling, -divisor labeling, square sum labeling, perfect square sum labeling, and strongly square sum labeling. This thesis consists of four chapters. In Chapter one, we introduce some basic definitions and notations in graph theory which we will need afterwards. Also, we deal with preliminary definitions and results about the related work in this thesis which have been done before. In Chapter two, we study combination graphs. We introduce some theorems for a graph to be a non-combination graph, and some theorems on chains of two and three complete graphs, considering when they are combination or non-combination graphs. Also we present some families of combination graphs. Finally we give a survey for trees of order ≤ 10, which are all combination graphs. In Chapter three, we discuss three kinds of divisor graphs, namely the usual divisor graph, the divisor cordial graph and a new divisor graph called - divisor graph. In Chapter four, we introduce a type of labeling of graphs which is closely related to the Diophantine Equation + . We introduce some families to be square sum graphs. We determine the number of strongly square sum graphs corresponding to the number of edges. We ii present a program finding the maximum number of edges of square sum and perfect square sum graphs. List of publications arising from this thesis [1] M. A. Seoud , M.N. Al-Harere, Some Notes on Combination Graphs, accepted for publication in Ars Combinatoria. [2] M.A.Seoud, M.N. Al-Harere ,On Combination Graphs, Int.Math.Forum ,7(2012)1767-1776. [3] M. A. Seoud , M.N. Al-Harere, Some Non-Combination Graphs, Applied Mathematical Sciences, 6( 2012), 6515 - 6520 . [4] M. A. Seoud , M.N. Al-Harere, Three Kinds of Divisor Graphs, preprint. [5] M. A. Seoud , M.N. Al-Harere, Further Results on Square Sum Graphs, accepted for National Academy Science Letters, Springer. |