the $k$-th semi total point graph $r^k(g)$ of a graph $g$, is a graph obtained from $g$ by adding $k$ vertices corresponding to each edge and connecting them to endpoint of edge considered. in this paper, we obtain formulae for the resistance distance and kirchhoff index of $r^k(g)$.

A connected graph $\G$ is called {\em nicely distance--balanced}, whenever there exists a positive integer $\gamma=\gamma(\G)$, such that for any two adjacent vertices $u,v$ of are exactly $\gamma$ which closer to $u$ than $v$, and $v$ $u$. Let $d$ denote the diameter $\G$. It known $d \le \gamma$, distance-balanced graphs with $\gamma = d$ precisely complete cycles length $2d$ or $2d+1$. In th...

Let Γ = (X, R) denote a distance-regular graph with distance function ∂ and diameter d ≥ 3. For 2 ≤ i ≤ d, by a parallelogram of length i, we mean a 4-tuple xyzu of vertices in X such that ∂(x, y) = ∂(z, u) = 1, ∂(x, u) = i, and ∂(x, z) = ∂(y, z) = ∂(y, u) = i − 1. Suppose the intersection number a1 = 0, a2 6= 0 in Γ. We prove the following (i)-(ii) are equivalent. (i) Γ is Q-polynomial and con...

The eccentricity e(v) of a vertex v in a strongly connected digraph G is the maximum distance from v. The eccentricity sequence of a digraph is the list of eccentricities of its vertices given in nondecreasing order. A sequence of positive integers is a digraphical eccentric sequence if it is the eccentricity sequence of some digraph. A set of positive integers S is a digraphical eccentric set ...

Let G be a connected graph of order n. The resistance matrix of G is defined as RG = (rij(G))n×n, where rij(G) is the resistance distance between two vertices i and j in G. Eigenvalues of RG are called R-eigenvalues of G. If all row sums of RG are equal, then G is called resistance-regular. For any connected graph G, we show that RG determines the structure of G up to isomorphism. Moreover, the...

We propose novel distributed exponentially-converging control frameworks for flocking and centroid trajectory tracking of multiple thrust-propelled vehicles (TPVs), which consist of the under-actuated translation dynamics on E(3) with one-dimensional thrust-force input and the fully-actuated attitude kinematics on SO(3) with angular-rates inputs; and evolves on a strongly-connected, yet, balanc...