5,101 research outputs found
Mass Storage Management and the Grid
The University of Edinburgh has a significant interest in mass storage
systems as it is one of the core groups tasked with the roll out of storage
software for the UK's particle physics grid, GridPP. We present the results of
a development project to provide software interfaces between the SDSC Storage
Resource Broker, the EU DataGrid and the Storage Resource Manager. This project
was undertaken in association with the eDikt group at the National eScience
Centre, the Universities of Bristol and Glasgow, Rutherford Appleton Laboratory
and the San Diego Supercomputing Center.Comment: 4 pages, 3 figures, Presented at Computing for High Energy and
Nuclear Physics 2004 (CHEP '04), Interlaken, Switzerland, September 200
ScotGrid: A Prototype Tier 2 Centre
ScotGrid is a prototype regional computing centre formed as a collaboration
between the universities of Durham, Edinburgh and Glasgow as part of the UK's
national particle physics grid, GridPP. We outline the resources available at
the three core sites and our optimisation efforts for our user communities. We
discuss the work which has been conducted in extending the centre to embrace
new projects both from particle physics and new user communities and explain
our methodology for doing this.Comment: 4 pages, 4 diagrams. Presented at Computing for High Energy and
Nuclear Physics 2004 (CHEP '04). Interlaken, Switzerland, September 200
Model-independent measurement of internal stellar structure in 16 Cygni A and B
We present a method for measuring internal stellar structure based on
asteroseismology that we call "inversions for agreement." The method accounts
for imprecise estimates of stellar mass and radius as well as the relatively
limited oscillation mode sets that are available for distant stars. By
construction, the results of the method are independent of stellar models. We
apply this method to measure the isothermal sound speeds in the cores of the
solar-type stars 16 Cyg A and B using asteroseismic data obtained from Kepler
observations. We compare the asteroseismic structure that we deduce against
best-fitting evolutionary models and find that the sound speeds in the cores of
these stars exceed those of the models.Comment: Accepted for publication in The Astrophysical Journa
The New Commandment John 13:34
The story is told of a visit that Bishop Ussher made to a certain Nobleman’s home. During the course of the evening meal the subject of religion was thoroughly discussed. One of the questions that, his host put to the Bishop was this: How many commandments are there? Without hesitation the bishop replied, Eleven, and quoted, as an addition to the Decalogue, the passage in St. John’s Gospel that is to serve as the basis for this thesis: A new commandment give I unto you, that ye love one another, as I have loved you, that ye also love one another
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Risk across design domains
Design processes involve risk: to life and limb if the product is unsafe, to the financial health of the company if the product is late, unsuccessful or simply the wrong product, as well as to the emotions and careers of the designers. Many of the risks are shared universally by all designers, but each different industry and each different project faces its own spectrum of serious and minor risks. Different industries have put their methodological effort into finding ways to mitigate the risks they recognise as important. As part of the Across Design project exploring similarities and differences between design processes in different industries, this paper examines how risks are perceived and handled in different types of design process, and proposes that designers and managers can usefully look to other industries for ways to handle risks that are more central for those other industries
Asteroseismology of KIC 8263801:Is it a member of NGC 6866 and a red clump star?
We present an asteroseismic analysis of the Kepler light curve of KIC
8263801, a red-giant star in the open cluster NGC 6866 that has previously been
reported to be a helium-burning red-clump star. We extracted the frequencies of
the radial and quadrupole modes from its frequency power spectrum and
determined its properties using a grid of evolutionary models constructed with
MESA. The oscillation frequencies were calculated using the GYRE code and the
surface term was corrected using the Ball & Gizon(2014) prescription. We find
that the star has a mass of , age Gyr and radius . By analyzing the internal
structure of the best-fitting model, we infer the evolutionary status of the
star KIC 8263801 as being on the ascending part of the red giant branch, and
not on the red clump. This result is verified using a purely asteroseismic
diagnostic, the diagram which can distinguish red
giant branch stars from red clump stars. Finally, by comparing its age with NGC
6866 ( Gyr) we conclude that KIC 8263801 is not a member of
this open cluster
Mitigating the mass dependence in the scaling relation of red-giant stars
The masses and radii of solar-like oscillators can be estimated through the
asteroseismic scaling relations. These relations provide a direct link between
observables, i.e. effective temperature and characteristics of the oscillation
spectra, and stellar properties, i.e. mean density and surface gravity (thus
mass and radius). These scaling relations are commonly used to characterize
large samples of stars. Usually, the Sun is used as a reference from which the
structure is scaled. However, for stars that do not have a similar structure as
the Sun, using the Sun as a reference introduces systematic errors as large as
10\% in mass and 5\% in radius. Several alternatives for the reference of the
scaling relation involving the large frequency separation (typical frequency
difference between modes of the same degree and consecutive radial order) have
been suggested in the literature. In a previous paper, we presented a reference
function with a dependence on both effective temperature and metallicity. The
accuracy of predicted masses and radii improved considerably when using
reference values calculated from our reference function. However, the residuals
indicated that stars on the red-giant branch possess a mass dependence that was
not accounted for. Here, we present a reference function for the scaling
relation involving the large frequency separation that includes the mass
dependence. This new reference function improves the derived masses and radii
significantly by removing the systematic differences and mitigates the trend
with (frequency of maximum oscillation power) that exists when
using the solar value as a reference.Comment: 12 pages, 7 figures, accepted for publication in MNRA
Response of corn yields to nitrogen fertilization and plant population in Missouri, 1961
Cover title."Progress report no. 1"."This report is a joint contribution of the Department of Soils and the Department of Agricultural Economics of the Missouri Agricultural Experiment Station. It is a progress report of Research Project 455, "The Economics of Fertilizer Use on Corn in Missouri."--Page 2
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