# Search results for: Ivan Gutman

Journal of Applied Mathematics and Computing > 2019 > 61 > 1-2 > 405-415

*m*edges, with vertex degree sequence $$d_1\ge d_2\ge \cdots \ge d_n$$ d 1 ≥ d 2 ≥ ⋯ ≥ d n , $$d_i=d(i)$$ d i = d ( i ) . The augmented Zagreb index is defined as $$AZI=\sum _{i\sim j}\left( \frac{d_i d_j}{d_i+d_j-2}\right)...

Applied Mathematics and Computation > 2018 > 337 > C > 461-468

_{G}(v

_{i}) denoting the degree and eccentricity of the vertex v

_{i}, the non-self-centrality number and the total irregularity of G are defined as N(G)=∑|ɛG(vj)−ɛG(vi)| and irrt(G)=∑|degG(vj)−degG(vi)|, with summations embracing all pairs of vertices. In this paper, we focus on relations between these two structural invariants. It is proved that irr

_{t}(G) > N(G)...

Journal of Mathematical Chemistry > 2019 > 57 > 2 > 609-615

Linear Algebra and its Applications > 2018 > 554 > C > 185-204

Linear Algebra and its Applications > 2018 > 554 > C > 170-184

International Journal of Quantum Chemistry > 118 > 17 > n/a - n/a

*symmetric division deg index*(

*SDD*). This article is devoted to a thorough...

Journal of Mathematical Chemistry > 2018 > 56 > 5 > 1493-1510

Journal of Mathematical Chemistry > 2018 > 56 > 5 > 1481-1492

Discussiones Mathematicae Graph Theory > 2017 > 38 > 1 > 83-95

Applied Mathematics and Computation > 2017 > 315 > C > 298-312

Discrete Applied Mathematics > 2017 > 232 > C > 189-200

Applied Mathematics and Computation > 2017 > 313 > C > 235-244

Journal of Biomedical Informatics > 2017 > 75 > C > 63-69

Linear Algebra and its Applications > 2017 > 529 > C > 30-50

Applied Mathematics and Computation > 2017 > 305 > C > 161-165

Journal of Mathematical Chemistry > 2017 > 55 > 10 > 1934-1940

*n*carbon atoms and

*m*carbon–carbon bonds. Its weak point is that it predicts equal $$E_\pi $$ E π -values for all isomers. We now show how...

Discrete Applied Mathematics > 2017 > 221 > C > 82-88

Discrete Applied Mathematics > 2017 > 219 > C > 167-175

Applied Mathematics and Computation > 2017 > 296 > C > 116-123

_{i}be the degree of the vertex v

_{i}of G. The extended adjacency matrix A

_{ex}of G is defined so that its (i, j)-entry is equal to 12(didj+djdi) if the vertices v

_{i}and v

_{j}are adjacent, and 0 otherwise,Yang et al. (1994). The spectral radius η

_{1}and the energy Eex of the A

_{ex}-matrix are examined. Lower and upper bounds on η

_{1}and Eex are obtained, and the respective...

Linear Algebra and its Applications > 2017 > 515 > C > 24-37