In a biconnected graph, a detour is the best alternative path from a detour-starting vertex to the destination vertex. A detour-starting vertex is the vertex from which the original shortest path is changed. The longest detour (LD) problem is to find a detour-critical edge in a shortest path such that the removal of the edge results in the maximum distance increment. In this paper, we deal with...

The Detour matrix (DD) of a graph has for its ( i , j) entry the length of the longest path between vertices i and j. The DD-eigenvalues of a connected graph G are the eigenvalues for its detour matrix, and they form the DD-spectrum of G. The DD-energy EDD of the graph G is the sum of the absolute values of its DDeigenvalues. Two connected graphs are said to be DDequienergetic if they have equa...

Let P be a simple polygon in 2 with n vertices. The detour of P between two points, p, q ∈ P , is the length of a shortest path contained in P and connecting p to q, divided by the distance of these points. The detour of the whole polygon is the maximum detour between any two points in P . We first analyze properties of pairs of points with maximum detour. Next, we use these properties to achie...

For a connected graph G = (V,E) of order at least two, a chord of a path P is an edge joining two non-adjacent vertices of P . A path P is called a monophonic path if it is a chordless path. A longest x− y monophonic path is called an x− y detour monophonic path. A set S of vertices of G is a detour monophonic set of G if each vertex v of G lies on an x − y detour monophonic path, for some x an...

Introduction Many patients suffer from unilateral or bilateral hydronephroses caused by pelvic tumors, retroperitoneal fibrosis, occlusion due to radiation therapy or iatrogenic damage to the ureter. Currently, percutaneous nephrostomy or double J stents are primarily used. Nephrostomy deteriorates a patient's quality of life and leads to frequent infections, blockage of tubes, or bleeding, whi...

For a connected graph G = (V,E) of order at least three, the monophonic distance dm(u, v) is the length of a longest u− v monophonic path in G. For subsets A and B of V , the monophonic distance dm(A,B) is defined as dm(A,B) = min{dm(x, y) : x ∈ A, y ∈ B}. A u− v path of length dm(A,B) is called an A−B detour monophonic path joining the sets A,B ⊆ V, where u ∈ A and v ∈ B. A set S ⊆ E is called...

To be useful in psychology "artificial organisms" have to perform tasks comparable to those performed by animals. One way to achieve this is to replicate actual animal experiments. Here we reproduce an experiment showing "detour behavior" in chicks a behavior usually explained in terms of "cognitive maps" or other forms of internal representation. We artificially evolve software-simulated robot...

motivated by the terminal wiener index‎, ‎we define the ashwini index $mathcal{a}$ of trees as‎ begin{eqnarray*}‎ % ‎nonumber to remove numbering (before each equation)‎ ‎mathcal{a}(t) &=& sumlimits_{1leq i‎&+& deg_{_{t}}(n(v_{j}))],‎ ‎end{eqnarray*}‎ ‎where $d_{t}(v_{i}‎, ‎v_{j})$ is the distance between the vertices $v_{i}‎, ‎v_{j} in v(t)$‎, ‎is equal to the length of the shortest path start...