3,635 research outputs found
IMPLEMENTACIÓN EN SIMUL8 DE UN MODELO SOBRE LOS DEPARTAMENTO DE ACCIDENTES Y EMERGENCIAS
Los departamentos de accidentes y emergencias son de gran interés en el área de la simulación de eventos discretos ya que por la importancia de los servicios que prestan se hace apremiante encontrar alternativas que hagan que su rendimiento en cuanto a tiempos de atención sea lo más óptimo posibles. En este trabajo se implementa en el software Simul8 un modelo genérico desarrollado por Günal y Pidd (2006) sobre estos departamentos con el fin de comprender el funcionamiento de estos sistemas y obtener respuestas de investigación sobre la implementación de modelos genéricos y la pertinencia de la simulación de eventos discretos para este tipo de sistemas.The departments of accidents and emergencies are very interesting in simulation and discrete events areas because the importance of the services that they give became important to find alternatives to make their performance in time attention the most optimal. In this work it’s carried out in the software Simul8 a generic model developed by Günal y Pidd (2006) about these departments in order to understand the performance of these systems and to get research answers about the carrying out of generic models and the relevance of simulation of discrete events for this kind of systems
Efeito da dinâmica de restos de culturas no sistema de plantio direto no cerrado sobre a ocorrência de artrópodes na rizosfera do milho.
Normalizing the Temperature Function of Clusters of Galaxies
We re-examine the constraints which can be robustly obtained from the
observed temperature function of X-ray cluster of galaxies. The cluster mass
function has been thoroughly studied in simulations and analytically, but a
direct simulation of the temperature function is presented here for the first
time. Adaptive hydrodynamic simulations using the cosmological Moving Mesh
Hydro code of Pen (1997a) are used to calibrate the temperature function for
different popular cosmologies. Applying the new normalizations to the
present-day cluster abundances, we find for a hyperbolic universe, and for a spatially flat universe with a cosmological constant.
The simulations followed the gravitational shock heating of the gas and dark
matter, and used a crude model for potential energy injection by supernova
heating. The error bars are dominated by uncertainties in the heating/cooling
models. We present fitting formulae for the mass-temperature conversions and
cluster abundances based on these simulations.Comment: 20 pages incl 5 figures, final version for ApJ, corrected open
universe \gamma relation, results unchange
Avaliação de antibiose em dialelos de milho selecionados para resistência a lagarta-do-cartucho, Spodoptera frugiperda.
Capacidade combinatória para desenvolvimento larval e ciclo biológico de Spodoptera frugiperda em seis linhagens da população de milho CMS 23.
Constraints on Cosmological Parameters from Future Galaxy Cluster Surveys
We study the expected redshift evolution of galaxy cluster abundance between
0 < z < 3 in different cosmologies, including the effects of the cosmic
equation of state parameter w=p/rho. Using the halo mass function obtained in
recent large scale numerical simulations, we model the expected cluster yields
in a 12 deg^2 Sunyaev-Zeldovich Effect (SZE) survey and a deep 10^4 deg^2 X-ray
survey over a wide range of cosmological parameters. We quantify the
statistical differences among cosmologies using both the total number and
redshift distribution of clusters. Provided that the local cluster abundance is
known to a few percent accuracy, we find only mild degeneracies between w and
either Omega_m or h. As a result, both surveys will provide improved
constraints on Omega_m and w. The Omega_m-w degeneracy from both surveys is
complementary to those found either in studies of CMB anisotropies or of
high-redshift Supernovae (SNe). As a result, combining these surveys together
with either CMB or SNe studies can reduce the statistical uncertainty on both w
and Omega_m to levels below what could be obtained by combining only the latter
two data sets. Our results indicate a formal statistical uncertainty of about
3% (68% confidence) on both Omega_m and w when the SZE survey is combined with
either the CMB or SN data; the large number of clusters in the X-ray survey
further suppresses the degeneracy between w and both Omega_m and h. Systematics
and internal evolution of cluster structure at the present pose uncertainties
above these levels. We briefly discuss and quantify the relevant systematic
errors. By focusing on clusters with measured temperatures in the X-ray survey,
we reduce our sensitivity to systematics such as non-standard evolution of
internal cluster structure.Comment: ApJ, revised version. Expanded discussion of systematics;
Press-Schechter mass function replaced by fit from simulation
Non-extensive processes associated with heating of the Galactic disc
We analyse the mechanisms ruling galactic disc heating through the dynamics
of space velocities , and , extracted from the Geneva-Copenhagen
catalogue. To do this, we use a model based on non-extensive statistical
mechanics, where we derive the probability distribution functions that quantify
the non-Gaussian effects. Furthermore, we find that the deviation at a
given stellar age follows non-random behaviour. As a result, the -index
behaviour indicates that the vertical component , perpendicular to the
Galactic plane, does not ``heat up'' at random, which is in disagreement with
previous works that attributed the evolution of to randomness. Finally, our
results bring a new perspective to this matter and open the way for studying
Galactic kinematic components through the eyes of more robust statistical
models that consider non-Gaussian effects.Comment: 7 pages, 3 figures, 2 tables. Accepted to EP
The Angular Power Spectrum of EDSGC Galaxies
We determine the angular power spectrum, C_l, of the Edinburgh/Durham
Southern Galaxy Catalog (EDSGC) and use this statistic to constrain
cosmological parameters. Our methods for determining C_l, and the parameters
that affect it are based on those developed for the analysis of cosmic
microwave background maps. We expect them to be useful for future surveys.
Assuming flat cold dark matter models with a cosmological constant (constrained
by COBE/DMR and local cluster abundances), and a scale--independent bias, b, we
find good fits to the EDSGC angular power spectrum with 1.11 < b < 2.35 and 0.2
< Omega_m < 0.55 at 95% confidence. These results are not significantly
affected by the ``integral constraint'' or extinction by interstellar dust, but
may be by our assumption of Gaussianity.Comment: 11 pages, 9 figures, version to appear in Ap
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