In this paper, we propose a new approach to the problem of subgraph isomorphism detection. The new method is designed for systems which di erentiate between graphs that are a priori known, so-called model graphs, and unknown graphs, so-called input graphs. The problem to be solved is to nd a subgraph isomorphism from an input graph, which is given on-line, to any of the model graphs. The new me...

The graph isomorphism problem is a main problem which has numerous applications in different fields. Thus, finding an efficient and easy to implement method to discriminate non-isomorphic graphs is valuable. In this paper, a new method is introduced which is very simple and easy to implement, but very efficient in discriminating non-isomorphic graphs, in practice. This method does not need any ...

Abstract: The present paper is focusing on the order, size and degree of the nodes of the interval-valued fuzzy graphs, which are isomorphic. Isomorphism between Interval-valued fuzzy graphs is proved to be an equivalence relation, whereas the Weak isomorphism is proved to be a partial order. Few properties of interval valued fuzzy graphs, which are self complementary, are discussed.

For every infinite sequence ω = x1x2 . . ., with xi ∈ {0, 1}, we construct an infinite 4-regular graph Xω. These graphs are precisely the Schreier graphs of the action of a certain self-similar group on the space {0, 1}∞. We solve the isomorphism and local isomorphism problems for these graphs, and determine their automorphism groups. Finally, we prove that all graphs Xω have intermediate growth.

We observe that for planar graphs, the geometric duality relation generates both 2-isomorphism and abstract duality. This observation has surprising consequence links, equivalence defined by isomorphisms of checkerboard graphs is same as 2-isomorphisms graphs.

The isomorphism problem is known to be efficiently solvable for interval graphs, while for the larger class of circular-arc graphs its complexity status stays open. We consider the intermediate class of intersection graphs for families of circular arcs that satisfy the Helly property. We solve the isomorphism problem for this class in logarithmic space. If an input graph has a Helly circular-ar...

The Induced Subtree Isomorphism problem takes as input a graph G and a tree T , and the task is to decide whether G has an induced subgraph that is isomorphic to T . This problem is known to be NP-complete on bipartite graphs, but it can be solved in polynomial time when G is a forest. We show that Induced Subtree Isomorphism can be solved in polynomial time when G is an interval graph. In cont...

ÐThis paper investigates the influence of the cost function on the optimal match between two graphs. It is shown that, for a given cost function, there are an infinite number of other cost functions that lead, for any given pair of graphs, to the same optimal error correcting matching. Furthermore, it is shown that well-known concepts from graph theory, such as graph isomorphism, subgraph isomo...

Graphs with high symmetry or regularity are the main source for experimentally hard instances of the notoriously difficult graph isomorphism problem. In this paper, we study the computational complexity of isomorphism testing for line graphs of t-(v, k, λ) designs. For this class of highly regular graphs, we obtain a worst-case running time of O(v ) for bounded parameters t, k, λ. In a first st...