12,706 research outputs found
An Investigation of Three Dimensional Displays for Real-Time, Safety-Critical Command/Control Applications: with application to Air Traffic Control
Submitted to the University of London for the degree of Doctor of Philosophy in Computer Scienc
Positioning system of the ANTARES Neutrino Telescope
Completed in May 2008, the ANTARES neutrino telescope is located 40 km off
the coast of Toulon, at a depth of about 2500 m. The telescope consists of 12
detect or lines housing a total of 884 optical modules. Each line is anchored
to the seabed and pulled taught by the buoyancy of the individual optical
modules and a top buoy. Due to the fluid nature of the sea-water detecting
medium and the flexible nature of the detector lines, the optical modules of
the ANTARES telescope can suffer from deviations of up to several meters from
the vertical and as such, real time positioning is needed. Real time
positioning of the ANTARES telescope is achieved by a combination of an
acoustic positioning system and a lattice of tiltmeters and compasses. These
independent and complementary systems are used to compute a global fit to each
individual detector line, allowing us to construct a 3 dimensional picture of
the ANTARES neutrino telescope with an accuracy of less than 10 cm. In this
paper we describe the positioning system of the ANTARES neutrino telescope and
discuss its performance during the first year of 12 line data taking.Comment: Proceedings of 31st ICRC conference, Lodz 2009, 4 pages, 3 picture
ELSA and the frontiers of astrometry
ELSA stands for the ambitious goal of `European Leadership in Space
Astrometry'. In this closing contribution I will examine how the ELSA network
has advanced this goal. I also look ahead to the time when the Gaia data will
be published and consider what needs to be done to maintain European
leadership.Comment: Closing remarks at the ELSA conference "Gaia: at the frontiers of
astrometry". Proceedings editors: C. Turon, F. Arenou & F. Meynadie
The mass of the young planet Pictoris b through the astrometric motion of its host star
The young massive Jupiters discovered with high-contrast imaging provide a
unique opportunity to study the formation and early evolution of gas giant
planets. A key question is to what extent gravitational energy from accreted
gas contributes to the internal energy of a newly formed planet. This has led
to a range of formation scenarios from 'cold' to 'hot' start models. For a
planet of a given mass, these initial conditions govern its subsequent
evolution in luminosity and radius. Except for upper limits from radial
velocity studies, disk modelling, and dynamical instability arguments, no mass
measurements of young planets are yet available to distinguish between these
different models. Here we report on the detection of the astrometric motion of
Beta Pictoris, the 21 Myr-old host star of an archetypical directly-imaged gas
giant planet, around the system's centre of mass. Subtracting the highly
accurate Hipparcos-Gaia proper motion from the internal 3-yr Hipparcos
astrometric data reveals the reflex motion of the star, giving a
model-independent planet mass of M=11+-2 MJup. This is consistent with
scenarios in which the planet is formed in a high-entropy state as assumed by
hot start models. The ongoing data collection by Gaia will in the near future
lead to mass measurements of other young gas giants and form a great asset to
further constrain early evolution scenarios.Comment: Nature Astronomy, Aug 20, 2018; 16 pages, 4 Figs, 2 Table
The Spatial Dictionary
This thesis and the corresponding portfolio ‘The Spatial Dictionary’ is an investigation into the use of written language as a generative and descriptive approach for the design of Interior spaces. The potential utility of the dictionary as an object is explored as a conceptual ‘tool-box’ for the use of Interior designers. The dictionary is to be viewed here as a mechanism to translate both concrete and abstract visual ‘concepts’ into a written commentary, using a defined list of terms, whilst inadvertently exploring the notion that the exploration of this spatial vocabulary gives us an insight into what constitutes interior space and design. This thesis investigates the position that spatial language is not simply one of identification of phenomena pertaining to space but it can also be used as a tool for the intention and creation of interior spaces and desig
Mg II flux and profile variability of hybrid-chromosphere stars
Results from an IUE investigation of the variability seen in the Mg II emission line fluxes and wind absorption components of hybrid-chromosphere stars are presented. Real Mg II flux variability is shown with most of the variation being long-term. This variability appears to be due to global changes in the Mg II surface activity. Major changes in the wind absorption component are not seen
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