552 research outputs found
Extraction of information about periodic orbits from scattering functions
As a contribution to the inverse scattering problem for classical chaotic
systems, we show that one can select sequences of intervals of continuity, each
of which yields the information about period, eigenvalue and symmetry of one
unstable periodic orbit.Comment: LaTeX, 13 pages (includes 5 eps-figures
A Diffusion Model for Classical Chaotic Compound Scattering
We consider the classical map proposed previously to be the exact classical
analogue of Rydberg Molecules calculated with the approximations relevant to
the multi-channel quantum defect theory. The resulting classical map is
analyzed at energies above the threshold for the Rydberg electron. At energies
very near to this threshold we find the possibility of bounded motion for
positive energy due to conserved tori as well as the possibility of forming a
compound system, i.e. a system where the particle is trapped for long times
before emerging again to the continuum. The compound scattering displays
unusual features for short time behavior. A diffusion model explains these
features.Comment: 29 pages, 16 eps figures, LaTeX (elsart), introduction and background
info improve
Engaging visitors of science festivals using augmented reality: asymmetrical modelling
Purpose
This paper aims to explore a complex combination of four realms of the experience economy in formulating memories and satisfaction among festival visitors by using augmented reality (AR), thus engaging visitors in the physical science experience. This study also identifies necessary conditions to achieve desired responses from visitors.
Design/methodology/approach
Asymmetrical modelling with fuzzy set qualitative comparative analysis (fsQCA) was used to investigate causal recipes of two configurations of the experience economy and evaluation of experience leading to both high and low scores from visitor engagement. Necessary condition analysis was applied to examine necessary predictors in visitor engagement. The proposed configuration model was tested by using data obtained from visitors to science festivals in the UK.
Findings
Five causal recipes explained the complex conditions in which visitors were more likely engaged in AR. Aesthetics, education, entertainment and satisfaction were necessary for high engagement among festival visitors.
Research limitations/implications
The results from fsQCA and analyses of necessary conditions help festival organizers improve visitor satisfaction and engagement in a memorable AR experience.
Originality/value
This empirical study deepens current festival understanding of how visitors experience AR by exploring combinations of complex configurations of the experience economy and evaluations of visitor experience based on memories and satisfaction. Unlike symmetrical approaches, asymmetrical modelling by using fsQCA can explore recipes for both high and low scores of visitor satisfaction and engagement. This is the first empirical study investigating necessary predictors of festival visitor behaviour
Inclined bottom boundary condition for the mild-slope equation
A finite element method is one of the most effective methods to analyze hydrodynamic behaviors in the coastal zone because it can be applied to irregular and complex geometry. However, it is not easy to treat the boundary condition properly under the condition of vertically inclined boundary. In this study, a numerical method for treatment of inclined bottom boundary in the finite element method is introduced. The mild-slope equation is used as a governing equation. Comparison with an analytical solution shows the validity of the present method
Compliance With Guideline-Directed Medical Therapy in Contemporary Coronary Revascularization Trials
Background: Despite the well-established benefits of secondary cardiovascular prevention, the importance of concurrent medical therapy in clinical trials of coronary revascularization is often overlooked. Objectives: The goal of this study was to assess compliance with guideline-directed medical therapy (GDMT) in clinical trials and its potential impact on the comparison between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). Methods: The Cochrane Central Register of Controlled Trials and MEDLINE were searched from 2005 to August 2017. Clinical trial registries and reference lists of relevant studies were also searched. Randomized controlled trials comparing PCI with drug-eluting stents versus CABG and reporting medical therapy after revascularization were included. The study outcome was compliance with GDMT, defined as the following: 1) any antiplatelet agent plus beta-blocker plus statin (GDMT1); and 2) any antiplatelet agent plus beta-blocker plus statin plus angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (GDMT2). Data collection and analysis were performed according to the methodological recommendations of The Cochrane Collaboration. Results: From a total of 439 references, 5 trials were included based on our inclusion and exclusion criteria. Overall, compliance with GDMT1 was low and decreased over time from 67% at 1 year to 53% at 5 years. Compliance with GDMT2 was even lower and decreased from 40% at 1 year to 38% at 5 years. Compliance with both GDMT1 and GDMT2 was higher in PCI than in CABG at all time points. Meta-regression suggested an association between lower use of GDMT1 and adverse clinical outcomes in PCI versus CABG at 5 years. Conclusions: Compliance with GDMT in contemporary clinical trials remains suboptimal and is significantly lower after CABG than after PCI, which may influence the comparison of clinical trial endpoints between those study groups
Search for Higgs bosons decaying to tautau pairs in ppbar collisions at sqrt(s) = 1.96 TeV
We present a search for the production of neutral Higgs bosons decaying into
tautau pairs in ppbar collisions at a center-of-mass energy of 1.96 TeV. The
data, corresponding to an integrated luminosity of 5.4 fb-1, were collected by
the D0 experiment at the Fermilab Tevatron Collider. We set upper limits at the
95% C.L. on the product of production cross section and branching ratio for a
scalar resonance decaying into tautau pairs, and we then interpret these limits
as limits on the production of Higgs bosons in the minimal supersymmetric
standard model (MSSM) and as constraints in the MSSM parameter space.Comment: 7 pages, 5 figures, submitted to PL
Measurement of three-jet differential cross sections d sigma-3jet / d M-3jet in p anti-p collisions at sqrt(s)=1.96 TeV
We present the first measurement of the inclusive three-jet differential
cross section as a function of the invariant mass of the three jets with the
largest transverse momenta in an event in p anti-p collisions at sqrt(s) = 1.96
TeV. The measurement is made in different rapidity regions and for different
jet transverse momentum requirements and is based on a data set corresponding
to an integrated luminosity of 0.7 fb^{-1} collected with the D0 detector at
the Fermilab Tevatron Collider. The results are used to test the three-jet
matrix elements in perturbative QCD calculations at next-to-leading order in
the strong coupling constant. The data allow discrimination between
parametrizations of the parton distribution functions of the proton.Comment: 10 pages, 4 figures, 2 tables, submitted to Phys. Lett. B, corrected
chi2 values for NNPD
Search for pair production of the scalar top quark in muon+tau final states
We present a search for the pair production of scalar top quarks
(), the lightest supersymmetric partners of the top quarks, in
collisions at a center-of-mass energy of 1.96 TeV, using data
corresponding to an integrated luminosity of {7.3 } collected with the
\dzero experiment at the Fermilab Tevatron Collider. Each scalar top quark is
assumed to decay into a quark, a charged lepton, and a scalar neutrino
(). We investigate final states arising from and
. With no significant excess of events observed above the
background expected from the standard model, we set exclusion limits on this
production process in the (,) plane.Comment: Submitted to Phys. Lett.
Measurements of inclusive W+jets production rates as a function of jet transverse momentum in ppbar collisions at sqrt{s}=1.96 TeV
This Letter describes measurements of inclusive W (--> e nu) + n jet cross
sections (n = 1-4), presented as total inclusive cross sections and
differentially in the nth jet transverse momentum. The measurements are made
using data corresponding to an integrated luminosity of 4.2 fb-1 collected by
the D0 detector at the Fermilab Tevatron Collider, and achieve considerably
smaller uncertainties on W +jets production cross sections than previous
measurements. The measurements are compared to next-to-leading order
perturbative QCD (pQCD) calculations in the n =1-3 jet multiplicity bins and to
leading order pQCD calculations in the 4-jet bin. The measurements are
generally in agreement with pQCD predictions, although certain regions of phase
space are identified where the calculations could be improved
Measurement of the ttbar production cross section using dilepton events in ppbar collisions
We present a measurement of the ttbar production cross section sigma(ttbar)
in ppbar collisions at sqrt{s} = 1.96 TeV using 5.4 fb-1 of integrated
luminosity collected with the D0 detector. We consider final states with at
least two jets and two leptons (ee, emu, mumu), and events with one jet for the
the emu final state as well. The measured cross section is sigma(ttbar)= 7.36
+0.90-0.79 (stat + syst) pb. This result combined with the cross section
measurement in the lepton + jets final state yields sigma(ttbar)=7.56
+0.63-0.56 (stat + syst) pb, which agrees with the standard model expectation.
The relative precision of 8% of this measurement is comparable to the latest
theoretical calculations.Comment: 9 pages, published in Phys. Lett.
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