Garcia and Stichtenoth discovered two towers of function fields that meet the Drinfeld-Vlăduţ bound on the ratio of the number of points to the genus. For one of these towers, Garcia, Pellikaan and Torres derived a recursive description of theWeierstrass semigroups associated to a tower of points on the associated curves. In this article, a non-recursive description of the semigroups is given a...

For a σ-finite measure preserving dynamical system (X,μ, T ), we formulate necessary and sufficient conditions for a Young tower (∆, ν, F ) to be a (measure theoretic) extension of the original system. Because F is pointwise dual ergodic by construction, one immediate consequence of these conditions is that the Darling Kac theorem carries over from F to T . One advantage of the Darling Kac theo...

The problem of structural stability of two medieval masonry towers is addressed. The geometrical and structural aspects of the towers were analysed and non-destructive tests were performed to assess the evolution of damage phenomena. The damage processes underway in some portions of the masonry were monitored using the Acoustic Emission (AE) technique. This method makes it possible to estimate ...

The creation of geometrically complex fluidic devices is a subject of broad fundamental and technological interest. Here, we demonstrate the fabrication of three-dimensional (3D) microvascular networks through direct-write assembly of a fugitive organic ink. This approach yields a pervasive network of smooth cylindrical channels (approximately 10-300 microm) with defined connectivity. Square-sp...

A dense granular suspension dripping on an imbibing surface is observed to give rise to slender mechanically stable structures that we call granular towers. Successive drops of grain-liquid mixtures are shown to solidify rapidly upon contact with a liquid absorbing substrate. A balance of excess liquid flux and drainage rate is found to capture the typical growth and height of the towers. The t...

Carabid inventories gained via pitfall trapping were compared to manual samples from light towers. A comparison of the two methods indicated that pitfall traps recorded a significantly higher diversity of carabids and were efficient in indicating changes of habitat conditions. Nevertheless, this method failed to give near-complete inventories of all carabid species present. Manual sampling at l...

A geometric characterization of the Arf invariant of a knot in the 3–sphere is given in terms of two kinds of 4–dimensional bordisms, half-gropes and Whitney towers. These types of bordisms have associated complexities class and order which filter the condition of bordism by an embedded annulus, i.e. knot concordance, and it is shown constructively that the Arf invariant is exactly the obstruct...

Code division multiple access (CDMA) networks allow subscribers to share frequencies, so optimizing revenue involves reserving channel equivalents to each market subject to signal-tointerference constraints at the radio towers. We present a yield management model inspired by those from the airline industry to optimize revenue under uncertainty. We describe the optimality conditions and develop ...

A polynomial time isomorphism test for graphs called k-contractible graphs for fixed k is included. The class of k-contractible graphs includes the graphs of bounded valence and the graphs of bounded genus. The algorithm several new ideas including: (1) It removes portions of the graph and replaces them with groups which are used to keep track of the symmetries of these portions. (2) It maintai...

We describe a comparative approach to micrometeorological measurements of surface energy, water vapor, and trace gas fluxes, in which mobile eddy correlation towers are moved among sites every 9–14 days, allowing both direct and indirect comparison of fluxes among ecosystem types. Structurally distinct ecosystems in Alaskan arctic tundra differed in the relationships between net radiation and s...