National Air Traffic Services

National Air Traffic Services (NATS) are concerned with ensuring low probabilities of errors in determining aircraft positions. In general, error probabilities depend on the tails of some probability distributions for which there has been no theoretical model. Analysis of radar performance is regularly undertaken by NATS to ensure radar performance is within safety limits, with the maximum range being dependent on the declared separation between aircraft. NATS brought two questions to the Study Group, involving the horizontal (azimuthal) errors in radar data and the vertical errors in altimetry system data. In both cases, NATS asked the Study Group to analyse the data and assess whether the probability distributions that are currently used are good models for the errors

Metamaterials and the mathematical Science of invisibility

In this chapter, we review some recent developments in the field of photonics: cloaking, whereby an object becomes invisible to an observer, and mirages, whereby an object looks like another one (say, of a different shape). Such optical illusions are made possible thanks to the advent of metamaterials, which are new kinds of composites designed using the concept of transformational optics. Theoretical concepts introduced here are illustrated by finite element computations.Comment: This is a book chapter. 22 pages, 7 figure

Wing-Dimorphism in Cymindis Cribricollis Dejean and C. Neglecta Haldeman (Coleoptera: Carabidae)

(excerpt) One hundred and forty-nine specimens of Cymindis cribricollis Dejean and fifteen specimens of C. neglecta Haldeman from Quebec were examined for wingdimorphism

Tau lepton Michel parameters and new physics

A complete discussion of the constraints on the Michel parameters and the ambiguities of their interpretation is presented. Estimators of new physics, optimized for a very wide class of hypotheses and models, are proposed.Comment: 12 pages, Latex, 2 PostScript figure