A permutation graph G of a graph G (or generalized prism) is obtained by taking two disjoint copies of G and adding an arbitrary matching between the copies. For the parameters diameter, radius, average distance, connectivity and edge-connectivity, we compare the values of the parameter for G and G. In particular we show that if G has no isolates and is not 2Kk for k odd, then there exists a pe...

In this note we solve the edge-connectivity augmentation problem over symmetric parity families. It provides a solution for the minimum T-cut augmentation problem. We also extend a recent result of C. Q. Zhang [8].

The Harary index of a graph is defined as the sum of reciprocals of distances between all pairs of vertices of the graph. In this paperweprovide anupper boundof theHarary index in terms of the vertex or edge connectivity of a graph. We characterize the unique graph with themaximumHarary index among all graphs with a given number of cut vertices or vertex connectivity or edge connectivity. In ad...

This paper introduces a method which provides robust tracking results and accurately segmented object boundaries in short computation time. The first step of the algorithm is to apply a novel edge detector on efficiently calculated color probability maps in an object-specific Fisher color space. The proposed edge detector exploits context information by finding the maximally stable boundaries o...

In this paper, we study both concepts of geodetic dominatingand edge geodetic dominating sets and derive some tight upper bounds onthe edge geodetic and the edge geodetic domination numbers. We also obtainattainable upper bounds on the maximum number of elements in a partitionof a vertex set of a connected graph into geodetic sets, edge geodetic sets,geodetic domin...

Keywords: mathematical morphology segmentation connected component attribute profile elongation area stability multiphoton microscopy In this paper, a method to segment elongated objects is proposed. It is based on attribute profiles and area stability. Images are represented as component trees using a threshold decomposition. Then, some attributes are computed on each node of the tree. Finally...

The vertex version of detour index was defined during the works on connected graph in chemistry. The edge versions of detour index have been introduced ecently. In this paper, the explicit relations among edge versions of detour index have been declared and due to these relations, we compute the edge detour indices for some well-known graphs.

the vertex-edge wiener index of a simple connected graph g is defined as the sum of distances between vertices and edges of g. two possible distances d_1(u,e|g) and d_2(u,e|g) between a vertex u and an edge e of g were considered in the literature and according to them, the corresponding vertex-edge wiener indices w_{ve_1}(g) and w_{ve_2}(g) were introduced. in this paper, we present exact form...

In this note we show that the edge-connectivity λ(G × H) of the direct product of graphs G and H is bounded below by min{λ(G)|E(H)|, λ(H)|E(G)|, δ(G × H)} and above by min{2λ(G)|E(H)|, 2λ(H)|E(G)|, δ(G×H)} except in some special cases when G is a relatively small bipartite graph, or both graphs are bipartite. Several upper bounds on the vertex-connectivity of the direct product of graphs are al...

Let H be a graph with a designated vertex s, where edges are weighted by nonnegative reals. Splitting edges e = {u, s} and e′ = {s, v} at s is an operation that reduces the weight of each of e and e′ by a real δ > 0 while increasing the weight of edge {u, v} by δ. It is known that all edges incident to s can be split off while preserving the edge-connectivity of H and that such a complete split...