63,462 research outputs found
Simultaneous acquisition of tracking data from two stations
A method and apparatus is described for obtaining simultaneous tracking data from two ground stations relative to a spacecraft, and in particular for obtaining two-way range and Doppler measurements with respect to the spacecraft using only one transponder on the spacecraft. The technique employs simultaneous transmission from two stations to produce a return signal with upper and lower sidebands resulting from the interference of the two transmissions. A transponder transmits the upper and lower sidebands centered about a carrier received by both stations. One station tracks the carrier and the other tracks a sideband aided by the carrier
The Crisis of 2007-09: Nature, Causes, and Reactions
This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Journal of Interntional Economic Law following peer review. The definitive publisher-authenticated version [Journal of International Economic Law 13(3):531-550 2010] is available online at: http://jiel.oxfordjournals.org/content/13/3/531.ful
Is there another major constituent in the atmosphere of Mars?
In view of the possible finding of several tens percent of inert gas in the atmosphere of Mars by an instrument on the descent module of the USSR's Mars 6 spacecraft, the likelihood of the correctness of this result was examined. The basis for the well-known fact that the most likely candidate is radiogenic argon is described. It is shown that, for the two important methods of investigating the atmosphere, earth-based CO2 is infrared absorption spectroscopy and S-band occultation, within the estimated 1 standard deviation uncertainties of these methods about 20% argon can be accommodated. Within the estimated 3 standard deviation uncertainties, more than 35% is possible. It is also stated that even with 35% argon the maximum value of heat transfer rate on the Viking 75 entry vehicle does not exceed the design value
ERTS B imagery to monitor large scale clearing and development programmes in the Daly Basin, northern territory
There are no author-identified significant results in this report
Quantum symmetries and the Weyl-Wigner product of group representations
In the usual formulation of quantum mechanics, groups of automorphisms of
quantum states have ray representations by unitary and antiunitary operators on
complex Hilbert space, in accordance with Wigner's Theorem. In the phase-space
formulation, they have real, true unitary representations in the space of
square-integrable functions on phase-space. Each such phase-space
representation is a Weyl-Wigner product of the corresponding Hilbert space
representation with its contragredient, and these can be recovered by
`factorising' the Weyl-Wigner product. However, not every real, unitary
representation on phase-space corresponds to a group of automorphisms, so not
every such representation is in the form of a Weyl-Wigner product and can be
factorised. The conditions under which this is possible are examined. Examples
are presented.Comment: Latex2e file, 37 page
Land development in the Daly Basin
There are no author-identified significant results in this report
Magnetic Accretion and Photopolarimetric Variability in Classical T Tauri Stars
We employ a Monte Carlo radiation transfer code to investigate the multi-
wavelength photopolarimetric variability arising from a spotted T Tauri star
surrounded by a dusty circumstellar disk. Our aim is to assess the ability of
the magnetic accretion model to explain the observed photopolarimetric
variability of classical T Tauri stars, and to identify potentially useful
observational diagnostics of T Tauri star/disk/spot parameters. We model a
range of spot sizes, spot latitudes, inner disk truncation radii, and system
inclination angles, as well as multiple disk and spot geometries. We find that
the amplitude, morphology, and wavelength dependence of the photopolarimetric
variability predicted by our models are generally consistent with existing
observations; a flared disk geometry is required to reproduce the largest
observed polarization levels and variations. Our models can further explain
stochastic polarimetric variability if unsteady accretion is invoked, in which
case irregular -- but correlated -- photometric variability is predicted, in
agreement with observations.
Potentially useful observational diagnostics of system parameters of interest
are discussed. We also investigate the reliability of modeling spot parameters
via analytic fits to multi-band photometric variations.Comment: 25 pages, 8 figures To be published in ApJ, 1999, 51
The effect of cultural background on metaphor interpretation
This article describes a study that investigated the ways in which Bangladeshi students interpreted metaphors used by their lecturers during a short course at a British university. The students were asked to interpret a number of metaphors presented in context. They were also asked to identify the value judgements that were being expressed through these metaphors in these particular contexts. Culture-specific assumptions about the target domains appeared to affect the students’ recognition of the lecturers’ attitudes to the issues they were discussing. In order to identify areas of disparity between the (working) cultures of the Bangladeshi students and their British lecturers, Hofstede’s (1980) cultural values questionnaire was administered. The students were found to be more likely than their lecturers to favour uncertainty avoidance, and to favour high power distance at work. The kinds of (mis)interpretations that the students made of (the evaluative content of) the metaphors appeared in accordance with these cultural differences. Implications of these findings are discussed
- …