2,774 research outputs found
RoboCup 2D Soccer Simulation League: Evaluation Challenges
We summarise the results of RoboCup 2D Soccer Simulation League in 2016
(Leipzig), including the main competition and the evaluation round. The
evaluation round held in Leipzig confirmed the strength of RoboCup-2015
champion (WrightEagle, i.e. WE2015) in the League, with only eventual finalists
of 2016 competition capable of defeating WE2015. An extended, post-Leipzig,
round-robin tournament which included the top 8 teams of 2016, as well as
WE2015, with over 1000 games played for each pair, placed WE2015 third behind
the champion team (Gliders2016) and the runner-up (HELIOS2016). This
establishes WE2015 as a stable benchmark for the 2D Simulation League. We then
contrast two ranking methods and suggest two options for future evaluation
challenges. The first one, "The Champions Simulation League", is proposed to
include 6 previous champions, directly competing against each other in a
round-robin tournament, with the view to systematically trace the advancements
in the League. The second proposal, "The Global Challenge", is aimed to
increase the realism of the environmental conditions during the simulated
games, by simulating specific features of different participating countries.Comment: 12 pages, RoboCup-2017, Nagoya, Japan, July 201
Host--parasite models on graphs
The behavior of two interacting populations, ``hosts''and ``parasites'', is
investigated on Cayley trees and scale-free networks. In the former case
analytical and numerical arguments elucidate a phase diagram, whose most
interesting feature is the absence of a tri-critical point as a function of the
two independent spreading parameters. For scale-free graphs, the parasite
population can be described effectively by
Susceptible-Infected-Susceptible-type dynamics in a host background. This is
shown both by considering the appropriate dynamical equations and by numerical
simulations on Barab\'asi-Albert networks with the major implication that in
the termodynamic limit the critical parasite spreading parameter vanishes.Comment: 10 pages, 6 figures, submitted to PRE; analytics redone, new
calculations added, references added, appendix remove
On the geometry of C^3/D_27 and del Pezzo surfaces
We clarify some aspects of the geometry of a resolution of the orbifold X =
C3/D_27, the noncompact complex manifold underlying the brane quiver standard
model recently proposed by Verlinde and Wijnholt. We explicitly realize a map
between X and the total space of the canonical bundle over a degree 1 quasi del
Pezzo surface, thus defining a desingularization of X. Our analysis relys
essentially on the relationship existing between the normalizer group of D_27
and the Hessian group and on the study of the behaviour of the Hesse pencil of
plane cubic curves under the quotient.Comment: 23 pages, 5 figures, 2 tables. JHEP style. Added references.
Corrected typos. Revised introduction, results unchanged
Servelle-Martorell syndrome with extensive upper limb involvement: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Effect of alloying on the microstructure, phase stability, hardness and partitioning behavior of a new dual-superlattice nickel-based superalloy
A novel y-y'-y" dual-superlattice superalloy, with promising mechanical
properties up to elevated temperatures was recently reported. The present work
employs state of the art chemical and spatial characterization techniques to
study the effect systematic additions of Mo, W and Fe and variations in Nb and
Al contents have on the phase fraction, thermal stability, elemental
partitioning and mechanical properties. Alloys were produced through arc
melting followed by heat treatment. Multi-scale characterization techniques and
hardness testing were employed to characterize their microstructure, thermal
stability and mechanical properties. Alterations in such properties or in
elemental partitioning behaviour were then explained through thermodynamic
modelling.
A modest addition of 1.8 at.% Mo had a strong effect on the microstructure
and thermal stability: it minimized microstructural coarsening during heat
treatments while not significantly decreasing the y' solvus temperature. A
reduction of Nb by 0.6 at.%, strongly reduced the y" volume fraction, without
affecting the y' volume fraction. The reduced precipitate fraction led to a
significant reduction in alloy hardness. Fe, added to achieve better
processability and reduced material cost, decreased the y' solvus temperature
and caused rapid microstructural coarsening during heat treatments, without
affecting alloy hardness. A reduction of Al by 0.4 at.%, reduced the y' volume
fraction and the y' solvus temperature, also without affecting alloy hardness.
The addition of 0.9 at.% W decreased the y' solvus temperature but increased
both precipitate volume fractions. These data will be invaluable to optimize
current alloy design and to inform future alloy design efforts
Qualities of Learning activities and Illustrations Provisions in the Recommended Chemistry Textbooks for Nigerian Secondary School Students
This study aimed at assessing the qualities of learning activities and illustrations in Nigerian Chemistry textbooks used at the penultimate grades. Five Chemistry textbooks were purposively selected from twenty-two approved and recommended Chemistry textbooks in which evaluation research design was used involving two research questions. The 5 selected Chemistry Textbooks were the instrument for data collection. Data collected were analyzed using QACEST proforma. Results of the study revealed a number of inadequacies in the learning activities and illustrations in these textbooks. It was also observed that none of the Chemistry textbooks emphasized learner centered approach of teaching and the constructivist approach writing
Faculty members engaging in transformative PETE: a feminist perspective
The purpose of this study was to describe sport pedagogy faculty members’ (FMs) efforts at engaging in transformative physical education teacher education (T-PETE). T-PETE stresses the importance of FMs creating social change through their pedagogical approach and begins by asking preservice teachers (PTs) to reflect on their perspectives and practices (Tinning, 2017 Tinning, R. (2017). Transformative pedagogies and physical education. In C. Ennis (Ed.), The Routledge handbook of physical education pedagogies (pp. 295–306). New York: Taylor & Francis. [Google Scholar]. Transformative pedagogies and physical education. In C. Ennis (Ed.), The Routledge handbook of physical education pedagogies (pp. 295–306). New York: Taylor & Francis; Ukpokodu, 2009. The practice of transformative pedagogy. Journal on Excellence in College Teaching, 20(2), 43–67.). Participants were three white, female, able-bodied, lesbian/gay sport pedagogy FMs. The study was conducted in the United States. Feminist theory and feminist pedagogy drove data collection and analysis. Data were collected by employing a series of qualitative methods. An inductive and deductive analysis revealed that FMs had specific T-PETE goals, content, and pedagogies. Furthermore, several factors served to facilitate and limit the FMs’ effectiveness when engaging in T-PETE. The findings suggest that program-wide PETE reform is necessary in the United States for creating social change, and influencing PTs perspectives and practices. In addition, they suggest that American PETE programs might benefit from greater diversity among the FMs who staff them
Uplifting and Inflation with D3 Branes
Back-reaction effects can modify the dynamics of mobile D3 branes moving
within type IIB vacua, in a way which has recently become calculable. We
identify some of the ways these effects can alter inflationary scenarios, with
the following three results: (1) By examining how the forces on the brane due
to moduli-stabilizing interactions modify the angular motion of D3 branes
moving in Klebanov-Strassler type throats, we show how previous slow-roll
analyses can remain unchanged for some brane trajectories, while being modified
for other trajectories. These forces cause the D3 brane to sink to the bottom
of the throat except in a narrow region close to the D7 brane, and do not
ameliorate the \eta-problem of slow roll inflation in these throats; (2) We
argue that a recently-proposed back-reaction on the dilaton field can be used
to provide an alternative way of uplifting these compactifications to Minkowski
or De Sitter vacua, without the need for a supersymmetry-breaking anti-D3
brane; and (3) by including also the D-term forces which arise when
supersymmetry-breaking fluxes are included on D7 branes we identify the 4D
supergravity interactions which capture the dynamics of D3 motion in D3/D7
inflationary scenarios. The form of these potentials sheds some light on recent
discussions of how symmetries constrain D term interactions in the low-energy
theory.Comment: JHEP.cls, 35 pages, 3 .eps figure
Observation of two new baryon resonances
Two structures are observed close to the kinematic threshold in the mass spectrum in a sample of proton-proton collision data, corresponding
to an integrated luminosity of 3.0 fb recorded by the LHCb experiment.
In the quark model, two baryonic resonances with quark content are
expected in this mass region: the spin-parity and
states, denoted and .
Interpreting the structures as these resonances, we measure the mass
differences and the width of the heavier state to be
MeV,
MeV,
MeV, where the first and second
uncertainties are statistical and systematic, respectively. The width of the
lighter state is consistent with zero, and we place an upper limit of
MeV at 95% confidence level. Relative
production rates of these states are also reported.Comment: 17 pages, 2 figure
Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−
The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
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