In the title compound, C(19)H(15)NO(4), the acridine system is essentially planar (r.m.s. deviation = 0.015 Å). The crystal packing exhibits π-π inter-actions between pairs of centrosymmetric mol-ecules, one of them between the central heterocyclic rings and others between the outer benzene rings of the acridine systems, with centroid-centroid distances of 3.692 (1) and 3.754 (1) Å, respectivel...

In the title compound, C11H9NO2Se, the pyridine and phenyl rings are almost perpendicular, with the dihedral angle between their mean planes being 79.16 (7)°. In the crystal, the mol-ecules pack so as to form ruffled sheets in the (110) plane connected by weak C-H⋯O inter-actions. In addition, there are weak π-π inter-actions between the mean planes of both the phenyl [centroid-centroid perpend...

In the title salt, C(18)H(19)N(4)O(+)·PF(6) (-), the dihedral angle between the benzimidazolium and benzimidazole ring systems is 16.24 (2)°. In the cation, a π-π inter-action is observed between the imidazolium ring and the benzene ring of the benzimidazole ring system [centroid-centroid distance = 3.5713 (11) Å]. The PF(6) (-) ion is disordered over two sites, with occupancies of 0.895 (2) an...

In 1998, Pandu Rangan et al. proved that locating the g-centroid for an arbitrary graph is -hard by reducing the problem of finding the maximum clique size of a graph to the g-centroid location problem. They have also given an efficient polynomial time algorithm for locating the g-centroid for maximal outerplanar graphs, Ptolemaic graphs, and split graphs. In this paper, we present an O(nm) tim...

In vision domain, large-scale natural datasets typically exhibit long-tailed distribution which has large class imbalance between head and tail classes. This poses difficulty in learning good representations for Recent developments have shown model can be learnt by decoupling the training into representation classifier balancing. However, these works pay insufficient consideration on effect lea...

Mutation is the main operator of differential evolution (DE), as it responsible for combining information distinct solutions to generate a donor vector. Aiming at improving search effectivity DE, previous research incorporated calculation centroids into DE mutations. In some existing methods, are simply calculated center selected (or, entire population); in other cases, one-step clustering used...

Clustering techniques are used to group up the transactions based on the relevancy. Cluster analysis is one of the primary data analysis method. The clustering process can be done in two ways such that Hierarchical clusters and partition clustering. Hierarchical clustering technique uses the structure and data values. The partition clustering technique uses the data similarity factors. Transact...

In the title compound, [Co(C7H4ClO2)2(C5H5N)2(H2O)], the Co(II) atom is six-coordinated by three O atoms from a bidentate and a monodentate 4-chloro-benzoate ligand, two N atoms from two pyridine ligands and a water O atom, giving a distorted octa-hedral geometry. In the crystal, the complex mol-ecules are connected by O-H⋯O hydrogen bonds and π-π interactions between the benzene rings [centroi...