Variable Neighborhood Search for Extremal Graphs, 24. Results about the clique number
نویسندگان
چکیده
A set of vertices S in a graph G is a clique if any two of its vertices are adjacent. The clique number ω is the maximum cardinality of a clique in G. A series of best possible lower and upper bounds on the difference, sum, ratio or product of ω and some other common invariants of G were obtained by the system AGX 2, and most of them proved either automatically or by hand. In the present paper, we report on such lower and upper bounds considering, as second invariant, minimum, average and maximum degree, algebraic, node and edge connectivities, index, average distance, remoteness, radius and diameter. MOTS-CLÉS : Cardinalité maximum d’une clique, Invariant, Graphe extrême, AGX
منابع مشابه
Variable Neighborhood Search for Extremal Graphs . 15 . On Bags and Bugs 1
Usual graph classes, such as complete graphs, paths, cycles and stars, frequently appear as extremal graphs in graph theory problems. Here we want to turn the reader’s attention to two novel, simply defined, graph classes that appear as extremal graphs in several graph theory problems. We call them bags and bugs. As examples of problems where bags and bugs appear, we show that balanced bugs max...
متن کاملCommon Neighborhood Graph
Let G be a simple graph with vertex set {v1, v2, … , vn}. The common neighborhood graph of G, denoted by con(G), is a graph with vertex set {v1, v2, … , vn}, in which two vertices are adjacent if and only if they have at least one common neighbor in the graph G. In this paper, we compute the common neighborhood of some composite graphs. In continue, we investigate the relation between hamiltoni...
متن کاملA Learning Optimization Algorithm in Graph Theory - Versatile Search for Extremal Graphs Using a Learning Algorithm
Using a heuristic optimization module based upon Variable Neighborhood Search (VNS), the system AutoGraphiX’s main feature is to find extremal or near extremal graphs, i.e., graphs that minimize or maximize an invariant. From the so obtained graphs, conjectures are found either automatically or interactively. Most of the features of the system relies on the optimization that must be efficient b...
متن کاملVariable neighborhood search for the maximum clique
Maximum clique is one of the most studied NP-hard optimization problem on graphs because of its simplicity and its numerous applications. A basic variable neighborhood search heuristic for maximum clique that combines greedy with the simplicial vertex test in its descent step is proposed and tested on standard test problems from the literature. Despite its simplicity, the proposed heuristic out...
متن کاملVariable Neighborhood Search for Extremal Graphs. 10. Comparison of Irregularity Indices for Chemical Trees
Chemical graphs, as other ones, are regular if all their vertices have the same degree. Otherwise, they are irregular, and it is of interest to measure their irregularity both for descriptive purposes and for QSAR/QSPR studies. Three indices have been proposed in the literature for that purpose: those of Collatz-Sinogowitz, of Albertson, and of Bell's variance of degrees. We study their propert...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Stud. Inform. Univ.
دوره 8 شماره
صفحات -
تاریخ انتشار 2010