We use the subgraph replacement method to prove a simple product formula for the tilings of an octagonal counterpart of Propp’s quasi-hexagons (Problem 16 in New Perspectives in Geometric Combinatorics, Cambridge University Press, 1999), called quasi-octagon.

We derived explicit formulae for the eccentric connectivity index and Wiener index of 2-dimensional square-octagonal TUC4C8(R) lattices with open and closed ends. New compression factors for both indices are also computed in the limit N-->∞.

We study statistical properties of energy spectra of a tight-binding model on the two-dimensional quasiperiodic Ammann-Beenker tiling. Taking into account the symmetries of nite approximants, we nd that the underlying universal level-spacing distribution is given by the Gaussian orthogonal random matrix ensemble, and thus diiers from the critical level-spacing distribution observed at the metal...

Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is requ...

Title of Document: SEPARATING THE EFFECTS OF GROUP SIZE, DENSITY, AND ENCLOSURE SIZE ON MOVEMENT AND USE OF SPACE IN DOMESTIC FOWL (Gallus gallus domesticus) Erin Hoerl Leone, Ph.D., 2008 Directed By: Professor Inmaculada Estevez, Department of Animal and Avian Science This project was designed to separate the confounded effects of group size, density, and enclosure size, and to examine the rol...

A novel phased array antenna with wide bandwidth and wide scan angle is presented. The radiating aperture of the phased array consists of periodically and closely spaced octagonal ring elements. Tight capacitive coupling between adjacent elements is realized by interdigitating the end portions of the ring elements. To improve the impedance matching of the individual antenna elements over wide f...

Normal and almost normal surfaces are essential tools for algorithmic 3-manifold topology, but to use them requires exponentially slow enumeration algorithms in a high-dimensional vector space. The quadrilateral coordinates of Tollefson alleviate this problem considerably for normal surfaces, by reducing the dimension of this vector space from 7n to 3n (where n is the complexity of the underlyi...

A numerical investigation was carried out in order to predict the effects of symmetric heating on irregular acoustic streaming in air-filled shallow enclosures. The fluid motion is driven by periodic vibration of the enclosure left wall. The vertical walls of the enclosure are adiabatic while the horizontal walls are heated symmetrically. A control-volume method based, explicit time-marching Fl...

A convenient mathematical formulation is given for the absolute lowfrequency response of an electrodynamic direct radiator loudspeaker mounted in a vented or unvented enclosure. The combined effects of speaker Q (ratio of reactance to resistance), enclosure size, and enclosure tuning are shown to control the convergence of the response curve towards ts asymptotic value. Mathematical criteria ar...

In this paper, a numerical model of rectangular enclosure with apertures and a real receiving dipole antenna is considered for the purpose of accurate electric shielding effectiveness calculation. Dipole antenna is often used in practice to measure the level of electromagnetic field at some points inside the enclosure in order to estimate its shielding efficiency. Transmission-line matrix (TLM)...