The terminal Wiener index TW = TW (G) of a graph G is equal to the sum of distances between all pairs of pendent vertices of G . This distance–based molecular structure descriptor was put forward quite recently [I. Gutman, B. Furtula, M. Petrović, J. Math. Chem. 46 (2009) 522–531]. In this paper we report results on TW of thorn graphs. Also a method for calculation of TW of dendrimers is descri...

A common problem encountered in recognizing signs in realscene images is the perspective deformation. In this paper, we employ a descriptor named Cross Ratio Spectrum for recognizing real scene signs. Particularly, this method will be applied in two different ways: recognizing a multi-component sign as an whole entity or recognizing individual components separately. For the second strategy, a g...

In the crystal structure of the title compound, C(14)H(23)NOSi, cyclic dimeric units are established by two very weak hydrogen bonds of the type C-H⋯N with an H⋯N distance which is only slightly shorter than the sum of the van der Waals radii of 2.75 Å. The graph-set descriptor on the unitary level is R(2) (2)(14) for the cyclic dimer.

In the title compound, C(8)H(12)N(2)O(2), mol-ecules are inter-connected by weak C-H⋯O contacts with H⋯O distances of 2.30 Å, resulting in the formation of chains along [100]. According to graph-set analysis, the unitary descriptor of these chains is C(5). In addition, there are π-π stacking inter-actions between pyrazole rings (centroid distance = 3.878 Å and ring plane distance = 3.26 Å).

The title compound, C14H16N2, is a pyrrole-2-carbaldimine ligand that shows an E conformation at the imine double bond. The dihedral angle between the rings is 78.3 (1)°. In the crystal, pairs of mol-ecules form centrosymmetric dimers [graph-set descriptor is presumably R(2)2(10)] via N-H⋯N hydrogen bonds between the pyrrole N-H group and the imine N atom of a neighbouring mol-ecule.

Molecular Field Topology Analysis (MFTA) [1] is a QSAR approach based on the local (atomic) descriptors. First, a so-called molecular supergraph is constructed which is a simple graph such that the molecular graphs of all training set structures can be represented as its subgraphs. A uniform descriptor set for the statistical analysis is obtained by superimposing each training set structure ont...

Medical content based retrieval systems are continuously researched and improved. Image segmentation techniques offer a possibility for improvements in the retrieval process. According to this, the aim of the paper is to examine a graph based segmentation technique when it is applied to content based retrieval systems for magnetic resonance images. For this purpose, an evaluation of seven descr...

Introduction: to identify the pattern-reversal visual evoked potential (PRVEP) waveform descriptor by evaluating discrete wavelet transform (DWT) in order to optimize stimulus in the diagnosis of anisometropia amblyopia. Materials and Methods: The PRVEP testing was performedfor 31 normal individuals and 35 patients with amblyopia. The stimuli were consisted of spatial frequencies of 1, 2, and 4...

Given a topological space T and a finite subset T0 of T , we associate two graphs with T and T0 that, under rather mild conditions, turn out to be a block graph and a tree, respectively. This construction is of interest, e.g., in the context of phylogenetic analysis where T may model a full ‘‘orbit’’ of a dynamical branching process, and T0 the set of its branching points. © 2008 Elsevier Ltd. ...