نتایج جستجو برای: eccentricity index

تعداد نتایج: 401509  

Journal: :iranian journal of mathematical chemistry 2012
m. ghorbani kh. malekjani a. khaki

the eccentricity connectivity index of a molecular graph g is defined as (g) = av(g)deg(a)ε(a), where ε(a) is defined as the length of a maximal path connecting a to othervertices of g and deg(a) is degree of vertex a. here, we compute this topological index forsome infinite classes of dendrimer graphs.

Journal: :razavi international journal of medicine 0
afsoon fazlinezhad associate professor of cardiology, razavi hospital, mashhad university of medical sciences, mashhad, ir iran; associate professor of cardiology, razavi hospital, mashhad university of medical sciences, mashhad, ir iran. tel: +98-5116668888, fax: +98-5116668887 fatemeh moodi cardiologist, cardiovascular center, research and education department, razavi hospital, mashhad, ir iran azra izanloo research and education department, razavi hospital, mashhad, ir iran

conclusions we found that ei and qp/qs ratio are significantly and positively associated and qp/qs ratio can be easily estimated by measuring ei in secundum type asd patients. background one of the inclusion criteria for applying atrial septal defect (asd) closing procedure is an increased pulmonary-to-systemic blood flow ratio (qp/qs). eccentricity index (ei) is associated with ventricular dys...

Journal: :iranian journal of mathematical chemistry 2014
f. koorepazan-moftakhar kh. fathalikhani

in this paper, we calculate the eccentric connectivity index and the eccentricity sequence of two infinite classes of fullerenes with 50 + 10k and 60 + 12k (k in n) carbon atoms.

The eccentricity of a vertex $v$ is the maximum distance between $v$ and anyother vertex. A vertex with maximum eccentricity is called a peripheral vertex.The peripheral Wiener index $ PW(G)$ of a graph $G$ is defined as the sum ofthe distances between all pairs of peripheral vertices of $G.$ In this paper, weinitiate the study of the peripheral Wiener index and we investigate its basicproperti...

Journal: :Symmetry 2017
Nazeran Idrees Muhammad Jawwad Saif Asia Rauf Saba Mustafa

The Zagreb eccentricity indices are the eccentricity reformulation of the Zagreb indices. Let H be a simple graph. The first Zagreb eccentricity index (E1(H)) is defined to be the summation of squares of the eccentricity of vertices, i.e., E1(H) = ∑u∈V(H) Symmetry 2016, 9, 7; doi: 10.3390/sym9010007 www.mdpi.com/journal/symmetry Article First and Second Zagreb Eccentricity Indices of Thorny Gra...

Journal: :iranian journal of mathematical chemistry 2013
h. s. ramane a. b. ganagi h. b. walikar

the wiener index w(g) of a connected graph g is defined as the sum of the distances betweenall unordered pairs of vertices of g. the eccentricity of a vertex v in g is the distance to avertex farthest from v. in this paper we obtain the wiener index of a graph in terms ofeccentricities. further we extend these results to the self-centered graphs.

2012
Guihai Yu Lihua Feng

The connective eccentricity index of a graph G is defined as ξce(G) = ∑ v∈V (G) d(v) ε(v) , where ε(v) and d(v) denote the eccentricity and the degree of the vertex v, respectively. In this paper we derive upper or lower bounds for the connective eccentricity index in terms of some graph invariants such as the radius, independence number, vertex connectivity, minimum degree, maximum degree etc....

2017
HANYUAN DENG Y. B. VENKATAKRISHNAN Ivan Gutman Y. B. Venkatakrishnan

The eccentricity of a vertex is the maximum distance from it to another vertex and the average eccentricity ecc (G) of a graph G is the mean value of eccentricities of all vertices of G. The harmonic index H (G) of a graph G is defined as the sum of 2 di+dj over all edges vivj of G, where di denotes the degree of a vertex vi in G. In this paper, we determine the unique tree with minimum average...

Journal: :The Journal of invasive cardiology 2013
Dennis T L Wong Angela G Bertaso Gary Y H Liew Viji S Thomson Michael S Cunnington James D Richardson Robert Gooley Siobhan Lockwood Ian T Meredith Matthew I Worthley Stephen G Worthley

BACKGROUND Significant paravalvular aortic regurgitation (PAR) after transcatheter aortic valve implantation (TAVI) is associated with negative clinical consequences. We hypothesize that increased eccentricity of the aortic annulus is associated with greater PAR. METHODS Patients with severe aortic stenosis underwent multidetector computed tomography (MDCT) before successful TAVI with the Med...

Journal: :iranian journal of mathematical chemistry 2012
m. saheli m. jalali rad

the geometric-arithmetic index is another topological index was defined as2 deg ( )deg ( )( )deg ( ) deg ( )g guv eg gu vga gu v  , in which degree of vertex u denoted by degg (u). wenow define a new version of ga index as 4( )2 ε ( )ε ( )( )ε ( ) ε ( )g ge uv e g g gu vga g  u v , where εg(u) isthe eccentricity of vertex u. in this paper we compute this new topological index for twogr...

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