2,936 research outputs found
Colouring Lines in Projective Space
Let be a vector space of dimension over a field of order . The
-Kneser graph has the -dimensional subspaces of as its vertices,
where two subspaces and are adjacent if and only if
is the zero subspace. This paper is motivated by the problem
of determining the chromatic numbers of these graphs. This problem is trivial
when (and the graphs are complete) or when (and the graphs are
empty). We establish some basic theory in the general case. Then specializing
to the case , we show that the chromatic number is when and
when . In both cases we characterise the minimal
colourings.Comment: 19 pages; to appear in J. Combinatorial Theory, Series
J/ Production in p+p and d+Au Collisions at = 200 GeV at STAR
We present analysis of J/ production over the range
in p+p and d+Au collisions using di-electron data taken during the 2008 run
with the STAR experiment at Brookhaven National Laboratory. STAR's unique
forward capabilities, especially the Forward Meson Spectrometer electromagnetic
calorimeter, allow us the possibility of investigating the intrinsic charm
components of the proton wave function using high- forward particles
produced in asymmetric partonic collisions. Mid-rapidity measurements in d+Au
collisions extend our understanding of the mechanisms underlying heavy
quarkonium production and its transport through cold nuclear matter.Comment: 4 pages, 3 figures, - to appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Identifying High Potential Police Officers and Role Characteristics.
Project commissioned in 2000 by the Metropolitan Police Service to carry out a psychometric assessment validation study as part of a career Pathways Project
Incorporating spatial variation in housing attribute prices: A comparison of geographically weighted regression and the spatial expansion method
Hedonic house price models typically impose a constant price structure on housing characteristics throughout an entire market area. However, there is increasing evidence that the marginal prices of many important attributes vary over space, especially within large markets. In this paper, we compare two approaches to examine spatial heterogeneity in housing attribute prices within the Tucson, Arizona housing market: the spatial expansion method and geographically weighted regression (GWR). Our results provide strong evidence that the marginal price of key housing characteristics varies over space. GWR outperforms the spatial expansion method in terms of explanatory power and predictive accuracy.
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