This paper analyzes dynamic channel assignment in cellular systems where the base stations are placed at random. Using a simple dynamic channel assignment algorithm, random systems are compared to an ideal hexagonal systems. Under log-normal shadow fading the random system has capacity within 1dB of the hexagonal system. This paper looks at both the uplink and downlink and finds that performanc...

The Padmakar-Ivan (PI) index is a Wiener-Szeged-like topological index which reflects certain structural features of organic molecules. The PI index of a graph G is the sum of all edges uv of G of the number of edges which are not equidistant from the vertices u and v. In this paper we obtain the second and third extremals of catacondensed hexagonal systems with respect to the PI index.

It is shown experimentally that GeSi nanocrystals in SiC created after high-dose Ge ion implantation and high-temperature annealing are hexagonal in a hexagonal 4H-SiC matrix and are of cubic structure in a cubic 3C-SiC matrix. This interesting fact could be explained by molecular dynamics as the force of the system nanocrystal-matrix to minimize its interface energy.

conclusions hexagonal water has no significant effect(s) on total cholesterol, hdl, and ldl; however, more experiments are needed to clarify all aspects of hexagonal water consumption on diabetes. background diabetes is one of the most prevalent abnormalities in all over the world. nowadays, there are lots of attempts to reduce its disturbances and defects by changing life style to access some ...

A simple way to calculate the number of k-matchings, k ~< 5, in hexagonal systems is presented. Some relations between the coefficients of the characteristic polynomial of the adjacency matrix of a hexagonal system and the number of matchings are obtained. (~) 1998 Elsevier Science B.V. All rights reserved

The Hofstadter problem is studied on the hexagonal lattice. We first establish a relation between the spectra for the hexagonal lattice and for its dual lattice, the triangular lattice. Following the idea of Faddeev and Kashaev, we then obtain the Bethe-Ansatz equations for this system.

Hexagonal dot packing seems to offer benefits for halftone printing compared to conventional square dot packing, but little practical experience has been reported. Taking advantage of recent refinements in digital electrophotographic (EP) printer technology, the authors conducted experiments on a commercially deployable system to assess whether the potential advantages of hexagonal dot packing ...

We predict the number of hexagonal systems consisting of 24 and 25 hexagons to be H 24 = 122237774262384 and H 25 = 606259305418149, with 6 and 5 signiicant digits, respectively. Further estimates for H n up to n = 31 are also given. Informally speaking, a hexagonal system can be viewed as a connected arrangement of hexagonal cells packed in the same way as the typical honeycomb arrangement in ...

Concave gold nanoplates are obtained in hexagonal liquid crystal (LLC) made of SDS (sodium dodecyl sulfate)/glycine/HAuCl(4) aqueous solution system where glycine plays the key role. All plates are single-crystals, characterized by {111} facets, with concave centers of regular hexagonal or triangular shapes, and with better electrocatalytic activity than gold nanoplates.