9,068 research outputs found
Objective multiscale analysis of random heterogeneous materials
The multiscale framework presented in [1, 2] is assessed in this contribution for a study of random heterogeneous materials. Results are compared to direct numerical simulations (DNS) and the sensitivity to user-defined parameters such as the domain decomposition type and initial coarse scale resolution is reported. The parallel performance of the implementation is studied for different domain decompositions
Towards Semantic Integration of Heterogeneous Sensor Data with Indigenous Knowledge for Drought Forecasting
In the Internet of Things (IoT) domain, various heterogeneous ubiquitous
devices would be able to connect and communicate with each other seamlessly,
irrespective of the domain. Semantic representation of data through detailed
standardized annotation has shown to improve the integration of the
interconnected heterogeneous devices. However, the semantic representation of
these heterogeneous data sources for environmental monitoring systems is not
yet well supported. To achieve the maximum benefits of IoT for drought
forecasting, a dedicated semantic middleware solution is required. This
research proposes a middleware that semantically represents and integrates
heterogeneous data sources with indigenous knowledge based on a unified
ontology for an accurate IoT-based drought early warning system (DEWS).Comment: 5 pages, 3 figures, In Proceedings of the Doctoral Symposium of the
16th International Middleware Conference (Middleware Doct Symposium 2015),
Ivan Beschastnikh and Wouter Joosen (Eds.). ACM, New York, NY, US
Tunneling conductance in Superconductor/Ferromagnet junctions: a self consistent approach
We evaluate the tunneling conductance of clean Ferromomagnet/Superconductor
junctions via a fully self-consistent numerical solution of the microscopic
Bogoliubov-DeGennes equations. We present results for a relevant range of
values of the Fermi wavevector mismatch (FWM), the spin polarization, and the
interfacial scattering strength. For nonzero spin polarization, the conductance
curves vary nonmonotonically with FWM. The FWM dependence of the
self-consistent results is stronger than that previously found in
non-self-consistent calculations, since, in the self-consistent case, the
effective scattering potential near the interface depends on the FWM. The
dependence on interfacial scattering is monotonic. These results confirm that
it is impossible to characterize both the the FWM and the interfacial
scattering by a single effective parameter and that analysis of experimental
data via the use of such one-parameter models is unreliable.Comment: 12 pages, including 8 figure
Theory of pixel lensing towards M31 I: the density contribution and mass of MACHOs
POINT-AGAPE is an Anglo-French collaboration which is employing the Isaac
Newton Telescope (INT) to conduct a pixel-lensing survey towards M31. In this
paper we investigate what we can learn from pixel-lensing observables about the
MACHO mass and fractional contribution in M31 and the Galaxy for the case of
spherically-symmetric near-isothermal haloes. We employ detailed pixel-lensing
simulations which include many of the factors which affect the observables. For
a maximum MACHO halo we predict an event rate in V of up to 100 per season for
M31 and 40 per season for the Galaxy. However, the Einstein radius crossing
time is generally not measurable and the observed full-width half-maximum
duration provides only a weak tracer of lens mass. Nonetheless, we find that
the near-far asymmetry in the spatial distribution of M31 MACHOs provides
significant information on their mass and density contribution. We present a
likelihood estimator for measuring the fractional contribution and mass of both
M31 and Galaxy MACHOs which permits an unbiased determination to be made of
MACHO parameters, even from data-sets strongly contaminated by variable stars.
If M31 does not have a significant population of MACHOs in the mass range
0.001-1 Solar masses strong limits will result from the first season of INT
observations. Simulations based on currently favoured density and mass values
indicate that, after three seasons, the M31 MACHO parameters should be
constrained to within a factor four uncertainty in halo fraction and an order
of magnitude uncertainty in mass (90% confidence). Interesting constraints on
Galaxy MACHOs may also be possible. For a campaign lasting ten years,
comparable to the lifetime of current LMC surveys, reliable estimates of MACHO
parameters in both galaxies should be possible. (Abridged)Comment: 21 pages, 14 figures. Submitted to MNRA
Flowering dynamics and seed production of Arachis pintoi and Arachis repens in the brazilian cerrados.
Adaptive phenotypic plasticity of the native forage grass Paspalum fasciculatum: a trait relevant to climatic changes in wetlands.
This study has been conducted to detect natural forage species having adaptive phenotypic plasticity in wetlands to withstand extreme conditions in drought/flooding cycles.(Embrapa Gado de Corte. Documentos, 216). Coordenador Roberto Giolo de Almeida. II SIGEE. Disponível em: . Acesso em: 01 dez. 2016
Oferta de implantes de prótesis total de cadera en Cataluña
El crecimiento exponencial de la oferta de implantes de prótesis total de cadera
hace difícil para el cirujano ortopédico establecer criterios de elección, por este motivo hemos realizado
un análisis de la oferta actual de los mismos. Se han identificado 67 modelos de implantes
de prótesis total de cadera primaria y 19 modelos de revisión comercializados en la comunidad
catalana por 24 empresas. El número de variables, de material o diseño de los distintos modelos,
sin tener en cuenta las diversas medidas de vástagos, cuellos y cótilos, ha sido de 55. Hemos encontrado
referencias bibliográficas de resultados clínicos de un 25% de las prótesis. El rango de
coste de los implantes ha sido de 70.000 a 300.570 pesetas para las prótesis cementadas, con un
precio medio de 172.805 pesetas; de 375.654 a 648.606 pesetas para las no cementadas, con un
precio medio de 480.301 pesetas, y de 412.552 a 713.000 pesetas de las prótesis de revisión, con
una media de 568.138 pesetas. Esta dispersión de modelos y precios es mayor que la de otros países
de nuestro entorno, y el porcentaje de publicaciones de resultados clínicos encontrado es algo
menor que el reportado por algunos autores. Frente a esta situación creemos que serían necesarios
estudios clínicos a largo término y sistemas de evaluación estandarizados para poder decidir
con criterios rigurosos si los nuevos implantes que aparecen en el mercado con costes más elevados
tienen ventajas suficientes para cambiar indicaciones de implantes largamente probados.The exponential growth of the different models of THA actually in offer makes
difficult to the orthopaedic surgeon to find sound criteria for the selection of the proper implant.
This paper is an attempt to analyse the models actually in offer. We have identified 67 primary
THAs types and 19 revision models, commercialised by 24 companies at the catalonian community.
The number of variables, materials or designs between different patterns, independently of the size
of femoral and acetabular components, has been of 55. Only 25% of implants are supported by
reports in the orthopaedic literature. The cost range of implants varied from 70,000 to 300,570 pts.
for cemented prosthesis (average: 172,895); from 375,654 to 648,606 pts. for cementless models
(average: 480,391); the cost range for revision models varied from 412,552 to 713,000 pts., with an
average of 568,138 pts. Such a variety of designs and prices is greater than in other countries
of our environment, and the percentage of reports about clinical results that we have found is
smaller than the noticed by some authors. We believe that it would be necessary some long term
prospective studies and standarized evaluation systems in order to decide if the newer implants,
with more expensive price, have enough advantages to substitute the classic implants widely used
Time Scales for transitions between free energy minima of a hard sphere system
Time scales associated with activated transitions between glassy metastable
states of a free energy functional appropriate for a dense hard sphere system
are calculated by using a new Monte Carlo method for the local density
variables. We calculate the time the system,initially placed in a shallow
glassy minimum of the free energy, spends in the neighborhood of this minimum
before making a transition to the basin of attarction of another free energy
minimum. This time scale is found to increase with the average density. We find
a crossover density near which this time scale increases very sharply and
becomes longer than the longest times accessible in our simulation. This scale
shows no evidence of dependence on sample size.Comment: 25 pages, Revtex, 6 postscript figures. Will appear in Phys Rev E,
March 1996 or s
Free Energy Landscape Of Simple Liquids Near The Glass Transition
Properties of the free energy landscape in phase space of a dense hard sphere
system characterized by a discretized free energy functional of the
Ramakrishnan-Yussouff form are investigated numerically. A considerable number
of glassy local minima of the free energy are located and the distribution of
an appropriately defined ``overlap'' between minima is calculated. The process
of transition from the basin of attraction of a minimum to that of another one
is studied using a new ``microcanonical'' Monte Carlo procedure, leading to a
determination of the effective height of free energy barriers that separate
different glassy minima. The general appearance of the free energy landscape
resembles that of a putting green: deep minima separated by a fairly flat
structure. The growth of the effective free-energy barriers with increasing
density is consistent with the Vogel-Fulcher law, and this growth is primarily
driven by an entropic mechanism.Comment: 10 pages, 6 postscript figures, uses iopart.cls and iopart10.clo
(included). Invited talk at the ICTP Trieste Conference on "Unifying Concepts
in Glass Physics", September 1999. To be published in J. Phys. Cond. Ma
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