Pilot interaction with automated airborne decision making systems

The use of advanced software engineering methods (e.g., from artificial intelligence) to aid aircraft crews in procedure selection and execution is investigated. Human problem solving in dynamic environments as effected by the human's level of knowledge of system operations is examined. Progress on the development of full scale simulation facilities is also discussed

Giant Flexoelectric Effect in Ferroelectric Epitaxial Thin Films

We report on nanoscale strain gradients in ferroelectric HoMnO3 epitaxial thin films, resulting in a giant flexoelectric effect. Using grazing-incidence in-plane X-ray diffraction, we measured strain gradients in the films, which were 6 or 7 orders of magnitude larger than typical values reported for bulk oxides. The combination of transmission electron microscopy, electrical measurements, and electrostatic calculations showed that flexoelectricity provides a means of tuning the physical properties of ferroelectric epitaxial thin films, such as domain configurations and hysteresis curves.Comment: Accepted by Phys. Rev. Let

Impact of reionization on CMB polarization tests of slow-roll inflation

Estimates of inflationary parameters from the CMB B-mode polarization spectrum on the largest scales depend on knowledge of the reionization history, especially at low tensor-to-scalar ratio. Assuming an incorrect reionization history in the analysis of such polarization data can strongly bias the inflationary parameters. One consequence is that the single-field slow-roll consistency relation between the tensor-to-scalar ratio and tensor tilt might be excluded with high significance even if this relation holds in reality. We explain the origin of the bias and present case studies with various tensor amplitudes and noise characteristics. A more model-independent approach can account for uncertainties about reionization, and we show that parametrizing the reionization history by a set of its principal components with respect to E-mode polarization removes the bias in inflationary parameter measurement with little degradation in precision.Comment: 9 pages, 6 figures; submitted to Phys. Rev.

Simple Scheme for Efficient Linear Optics Quantum Gates

We describe the construction of a conditional quantum control-not (CNOT) gate from linear optical elements following the program of Knill, Laflamme and Milburn [Nature {\bf 409}, 46 (2001)]. We show that the basic operation of this gate can be tested using current technology. We then simplify the scheme significantly.Comment: Problems with PDF figures correcte

Better age estimations using UV-optical colours: breaking the age-metallicity degeneracy

We demonstrate that the combination of GALEX UV photometry in the FUV (~1530 angstroms) and NUV (~2310 angstroms) passbands with optical photometry in the standard U,B,V,R,I filters can efficiently break the age-metallicity degeneracy. We estimate well-constrained ages, metallicities and their associated errors for 42 GCs in M31, and show that the full set of FUV,NUV,U,B,V,R,I photometry produces age estimates that are ~90 percent more constrained and metallicity estimates that are ~60 percent more constrained than those produced by using optical filters alone. The quality of the age constraints is comparable or marginally better than those achieved using a large number of spectrscopic indices.Comment: Published in MNRAS (2007), 381, L74 (doi: 10.1111/j.1745-3933.2007.00370.x

Exactly Soluble Quantum Wormhole in Two Dimensions

We are presenting a quantum traversable wormhole in an exactly soluble two-dimensional model. This is different from previous works since the exotic negative energy that supports the wormhole is generated from the quantization of classical energy-momentum tensors. This explicit illustration shows the quantum-mechanical energy can be used as a candidate for the exotic source. As for the traversability, after a particle travels through the wormhole, the static initial wormhole geometry gets a back reaction which spoils the wormhole structure. However, it may still maintain the initial structure along with the appropriate boundary condition.Comment: v1. 13 pages, 1 figure, REVTeX3; v2. 1 Ref. added, REVTeX4, to appear in Phys. Rev.

Rotating Black Hole Entropy from Two Different Viewpoints

Using the brick-wall method, we study the entropy of Kerr-Newman black hole from two different viewpoints, a rest observer at infinity and zero angular momentum observer near horizon. We investigate this with scalar field in the canonical quantization approach. An observer at infinity can take one of the two possible frequency ranges; one is with positive frequencies only and the other is with the whole range including negative frequencies. On the other hand, a zero angular momentum observer near horizon can take positive frequencies only. For the observer at infinity the superradiant modes appear in either choice of the frequency ranges and the two results coincide. For the zero angular momentum observer superradiant modes do not appear due to absence of ergoregion. The resulting entropies from the two viewpoints turn out to be the same.Comment: LaTeX 18 pages, 2 figures, Minor modifications in section 3(ZAMO