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We use absolute trigonometric parallaxes from the Hipparcos Catalogue to determine individual distances to members of the Hyades cluster, from which the 3-dimensional structure of the cluster can be derived. Inertially-referenced proper motions are used to rediscuss distance determinations based on convergent-point analyses. A combination of parallaxes and(More)
A comprehensive census of the stellar content of the OB associations within 1 kpc from the Sun is presented, based on Hipparcos positions, proper motions, and parallaxes. It is a key part of a long-term project to study the formation, structure, and evolution of nearby young stellar groups and related star-forming regions. OB associations are unbound(More)
Current developments in grid and service oriented technologies involve fluid and dynamic, ad hoc based interactions between delegates, which in turn, serves to challenge conventional centralised structured trust and security assurance approaches. Delegates ranging from individuals to large-scale VO (Virtual Organisations) require the establishment of trust(More)
Keywords: Grid Grid scheduling Critical friend model (CFM) Self-led critical friend Inter-cooperative grid a b s t r a c t For decades, much work has been done to increase the effectiveness and efficiency of job sharing amongst available computational resources. Resources can be organized into a variety of topologies, and recent work has shown that a(More)
This paper presents data from the English Channel area of Britain and Northern France on the spatial distribution of Lower to early Middle Palaeolithic pre-MIS5 interglacial sites which are used to test the contention that the pattern of the richest sites is a real archaeological distribution and not of taphonomic origin. These sites show a marked(More)
1. Floodplain environments are increasingly subject to enhancement and restoration, with the purpose of increasing their biodiversity and returning them to a more 'natural' state. Defining such a state based solely upon neoecological data is problematic and has led several authors to suggest the use of a palaeoecological approach. 2. Fossil Coleopteran(More)
In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: Abstract Despite being the most important source of pollen and spore input into most(More)
Gaia is ESA's ambitious space astrometry mission with a main objective to astrometrically and spectro-photometrically map not Gaia Data Processing Architecture 3 less than 1000 million celestial objects in our galaxy with unprecedented accuracy. The announcement of opportunity (AO) for the data processing will be issued by ESA late in 2006. The Gaia Data(More)