This paper studies the construction of highly symmetric compactly supported wavelets for hexagonal data/image and triangle surface multiresolution processing. Recently hexagonal image processing has attracted attention. Compared with the conventional square lattice, the hexagonal lattice has several advantages, including that it has higher symmetry. It is desirable that the filter banks for hex...

A first-principles pseudopotential study of neutral self-interstitial defects in silicon is reported, together with calculations for Pandey’s concerted exchange mechanism for selfdiffusion. The energies and structures of the fully relaxed hexagonal, tetrahedral, split-〈110〉, ‘caged’ (Clark S J and Ackland G J 1997 Phys. Rev. B 56 47), split-〈100〉, and bond-centred interstitials are calculated u...

Convex hexagonal systems (CHS) i. e., hexagonal systems with no bay regions are studied. Among CHS with a fixed number of hexagons, the species with minimal/maximal number of inlets have minimal/maximal or maximal/minimal values for a variety of vertex–degree-based topological indices. These extremal CHS are characterized. 1 Convex hexagonal systems In this paper we study a special class of hex...

Silicon crystallizes in the diamond-cubic phase and shows only a weak emission at 1.1 eV. Diamond-hexagonal silicon however has an indirect bandgap at 1.5 eV and has therefore potential for application in opto-electronic devices. Here we discuss a method based on advanced silicon device processing to form diamond-hexagonal silicon nano-ribbons. With an appropriate temperature anneal applied to ...

Two-dimensional stacks of dissimilar hexagonal monolayers exhibit unusual electronic, photonic and photovoltaic responses that arise from substantial interlayer excitations. Interband excitation phenomena in individual hexagonal monolayer occur in states at band edges (valleys) in the hexagonal momentum space; therefore, low-energy interlayer excitation in the hexagonal monolayer stacks can be ...

Hexagonal hierarchical microtubular structures are produced by diphenylalanine self-assembly and the ratio of the relative humidity in the growth chamber to the diphenylalanine concentration (defined as the RH-FF ratio) determines the microtubular morphology. The hexagonal arrangement of the diphenylalanine molecules first induces the hexagonal nanotubes with opposite charges on the two ends, a...

In this paper, circular and hexagonal array geometries for smart antenna applications are compared. Uniform circular (UCA) and hexagonal arrays (UHA) with 18 half-wave dipole elements are examined; also planar (2 concentric rings of radiators) uniform circular (PUCA) and hexagonal arrays (PUHA) are considered. The effect of rotating the outer ring of the PUCA is studied. In our analysis, the me...

In this paper, an artificial neural network model is proposed to find out the resonant frequency of a metamaterial based Hexagonal Split Ring Resonator (SRR). The main advantage of Hexagonal SRR is small electrical size at resonance (electrically small) in the microwave regime. The method can be used for a wide range of different depending parameters (effective radius of the Hexagonal ring, spl...

In this paper we investigate the advantages of using hexagonal grids in raster and volume graphics. In 2D, we present a hexagonal graphical model based on a hexagonal grid. In 3D, we introduce two honeycomb graphical models in which the voxels are hexagonal prisms, and we show that these are the only possible models under certain reasonable conditions. In the framework of the proposed models, w...