9,830 research outputs found
JetWeb: A WWW Interface and Database for Monte Carlo Tuning and Validation
A World Wide Web interface to a Monte Carlo validation and tuning facility is
described. The aim of the package is to allow rapid and reproducible
comparisons to be made between detailed measurements at high-energy physics
colliders and general physics simulation packages. The package includes a
relational database, a Java servlet query and display facility, and clean
interfaces to simulation packages and their parameters.Comment: See http://jetweb.hep.ucl.ac.uk for further informatio
Satellite communications experiment for the Ontario air ambulance service
A satellite communications experiment was conducted to develop a reliable voice communications system between paramedics and doctors at certain larger medical centers. The experiment used INMARSAT's Atlantic Ocean Region satellite which provides coverage to the western border of Ontario. Forward downlink power from the satellite is in great demand, so two highly power-efficient modulation schemes were chosen for evaluation during the experiment. These were amplitude-companded single-sideband (ACSSB) and linear predictive coding in conjunction with DMSK modulation. Good performance with a signal to noise ratio of about 10 dB was demonstrated from many parts of the province with the evevation angle to the satellite ranging from five to twenty degrees and with the aircraft both in-flight and on the runway
The CEDAR Project
We describe the plans and objectives of the CEDAR project (Combined e-Science
Data Analysis Resource for High Energy Physics) newly funded by the PPARC
e-Science programme in the UK. CEDAR will combine the strengths of the well
established and widely used HEPDATA database of HEP data and the innovative
JetWeb data/Monte Carlo comparison facility, built on the HZTOOL package, and
will exploit developing grid technology. The current status and future plans of
both of these individual sub-projects within the CEDAR framework are described,
showing how they will cohesively provide (a) an extensive archive of Reaction
Data, (b) validation and tuning of Monte Carlo programs against these reaction
data sets, and (c) a validated code repository for a wide range of HEP code
such as parton distribution functions and other calculation codes used by
particle physicists. Once established it is envisaged CEDAR will become an
important Grid tool used by LHC experimentalists in their analyses and may well
serve as a model in other branches of science where there is a need to compare
data and complex simulations.Comment: 4 pages, 4 postscript figures, uses CHEP2004.cls. Presented at
Computing in High-Energy Physics (CHEP'04), Interlaken, Switzerland, 27th
September - 1st October 200
A new jet algorithm based on the k-means clustering for the reconstruction of heavy states from jets
A jet algorithm based on the k-means clustering procedure is proposed which
can be used for the invariant-mass reconstruction of heavy states decaying to
hadronic jets. The proposed algorithm was tested by reconstructing E+ E- to
ttbar to 6 jets and E+ E- to W+W- to 4 jets processes at \sqrt{s}=500 GeV using
a Monte Carlo simulation. It was shown that the algorithm has a reconstruction
efficiency similar to traditional jet-finding algorithms, and leads to 25% and
40% reduction of reconstruction width for top quarks and W bosons,
respectively, compared to the kT (Durham) algorithm. In addition, it is
expected that the peak positions measured with the new algorithm have smaller
systematical uncertainty.Comment: 11 pages, 3 eps figures (Eur. Phys. J. C, in press
Terrorist Attacks On Public Bus Transportation: A Preliminary Empirical Analysis, MTI Report WP 09-01
This report provides data on terrorist attacks against public bus transportation targets and serious crimes committed against such targets throughout the world. The data are drawn from the MTI database of attacks on public surface transportation, which is expanded and updated as information becomes available. This analysis is based on the database as of December 17, 2009. Data include the frequency and lethality with which buses, bus stations, and bus stops are attacked; the relationship between fatalities and attacks against bus targets and the relationship between injuries and attacks against those targets; how often, relative to other surface transportation targets, buses are attacked, first with all weapons and then with only explosive and incendiary devices; the relative lethality of attacks; and the distribution of attacks. It then presents some preliminary observations drawn from those data that can help stakeholders governments, transit managers, and employees to focus on the ways the most frequent and/or most lethal attacks are carried out as they consider measures to prevent or mitigate attacks that may be considered likely to happen in the United States
RunMC - an object-oriented analysis framework for Monte Carlo simulation of high-energy particle collisions
RunMC is an object-oriented framework aimed to generate and to analyse
high-energy collisions of elementary particles using Monte Carlo simulations.
This package, being based on C++ adopted by CERN as the main programming
language for the LHC experiments, provides a common interface to different
Monte Carlo models using modern physics libraries. Physics calculations
(projects) can easily be loaded and saved as external modules. This simplifies
the development of complicated calculations for high energy physics in large
collaborations.This desktop program is open-source licensed and is available on
the LINUX and Windows/Cygwin platforms.Comment: 15 pages, 1 eps figure, accepted by Comp. Phys. Commu
Five key issues with implications for draft WCRL FCPs
The following are amongst the major issues raised the draft FCPs and associated deadlines put forward by WWF/SASSI.
There are various inter-relationships amongst these issues. The intent of this document is to summarise these so that the current draft FCP deadlines can be re-assessed in this context
Infertility problems and mental health symptoms in a community-based sample: depressive symptoms among infertile men, but not women
Most researchers agree that men’s and women’s experiences of infertility are
fundamentally different, and impacts upon the nature of psychological distress
encountered. However, design flaws, including non-random samples
unrepresentative of the general population, compromise many existing studies. Data
derived from a random general community sample provides prevalence of current
infertility, and permits examination of longitudinal associations between mental
health symptoms and infertility among 1,978 participants aged 28-32 years. In the
previous 12-months, infertility was experienced by 2.1% and 5.4% partnered men
and women. Infertility independently predicted depressive symptomatology in men,
and anxiety symptoms among women. Gender differences were sustained, even
controlling for prior depression and anxiety. Health professionals are encouraged
to proactively enquire about affective symptoms experienced by both women and
men with infertility problems
Clarification regarding population growth rate parameters used for Southern Hemisphere humpback whales analyses
Papers on the dynamics of Southern Hemisphere humpback whales have described their growth rates in different ways. To attempt a simple summary, the following have been used (sometimes with different symbols to denote them or different forms of words to describe them): d : instantaneous growth rate (units yr–1) (sometimes indicated as r) l : annual growth rate (units yr–1) r : intrinsic growth rate (units yr–1) (sometimes indicated as rmax
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