7,054 research outputs found
Testing M2T/T2M Transformations
Presentado en: 16th International Conference on Model Driven Engineering Languages and Systems (MODELS 2013). Del 29 de septiembre al 4 de octubre. Miami, EEUU.Testing model-to-model (M2M) transformations is becoming a prominent topic in the current Model-driven Engineering landscape. Current approaches for transformation testing, however, assume having explicit model representations for the input domain and for the output domain of the transformation. This excludes other important transformation kinds, such as model-to-text (M2T) and text-to-model (T2M) transformations, from being properly tested since adequate model representations are missing either for the input domain or for the output domain. The contribution of this paper to overcome this gap is extending Tracts, a M2M transformation testing approach, for M2T/T2M transformation testing. The main mechanism we employ for reusing Tracts is to represent text within a generic metamodel. By this, we transform the M2T/T2M transformation specification problems into equivalent M2M transformation specification problems. We demonstrate the applicability of the approach by two examples and present how the approach is implemented for the Eclipse Modeling Framework (EMF). Finally, we apply the approach to evaluate code generation capabilities of several existing UML tools.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech. Proyecto TIN2011-2379
Nuclear shape dependence of Gamow-Teller distributions in neutron-deficient Pb isotopes
We study Gamow-Teller strength distributions in the neutron-deficient even
isotopes (184-194)Pb in a search for signatures of deformation. The microscopic
formalism used is based on a deformed quasiparticle random phase approximation
(QRPA) approach, which involves a self-consistent quasiparticle deformed Skyrme
Hartree-Fock (HF) basis and residual spin-isospin forces in both the
particle-hole and particle-particle channels. By analyzing the sensitivity of
the Gamow-Teller strength distributions to the various ingredients in the
formalism, we conclude that the beta-decay of these isotopes could be a useful
tool to look for fingerprints of nuclear deformation.Comment: 20 pages, 11 figures. To be published in Physical Review
Griffiths Inequalities for Ising Spin Glasses on the Nishimori Line
The Griffiths inequalities for Ising spin glasses are proved on the Nishimori
line with various bond randomness which includes Gaussian and bond
randomness. The proof for Ising systems with Gaussian bond randomness has
already been carried out by Morita et al, which uses not only the gauge theory
but also the properties of the Gaussian distribution, so that it cannot be
directly applied to the systems with other bond randomness. The present proof
essentially uses only the gauge theory, so that it does not depend on the
detail properties of the probability distribution of random interactions. Thus,
the results obtained from the inequalities for Ising systems with Gaussian bond
randomness do also hold for those with various bond randomness, especially with
bond randomness.Comment: 13pages. Submitted to J. Phys. Soc. Jp
Global Cosmological Parameters Determined Using Classical Double Radio Galaxies
A sample of 20 powerful extended radio galaxies with redshifts between zero
and two were used to determine constraints on global cosmological parameters.
Data for six radio sources were obtained from the VLA archive, analyzed, and
combined with the sample of 14 radio galaxies used previously by Guerra & Daly
to determine cosmological parameters. The results are consistent with our
previous results, and indicate that the current value of the mean mass density
of the universe is significantly less than the critical value. A universe with
of unity is ruled out at 99.0% confidence, and the best fitting
values of in matter are and
assuming zero space curvature and zero cosmological
constant, respectively. Note that identical results obtain when the low
redshift bin, which includes Cygnus A, is excluded; these results are
independent of whether the radio source Cygnus A is included. The method does
not rely on a zero-redshift normalization.
The radio properties of each source are also used to determine the density of
the gas in the vicinity of the source, and the beam power of the source. The
six new radio sources have physical characteristics similar to those found for
the original 14 sources. The density of the gas around these radio sources is
typical of gas in present day clusters of galaxies. The beam powers are
typically about .Comment: 39 pages includes 21 figures, accepted to Ap
Localized pulsed nanosecond discharges in a counterflow nonpremixed flame environment
A flame is a very unusual environment for the development of a gas discharge, since it presents strong gradients in temperature, composition, and pre-ionization. In this paper we examine how such an environment impacts the development of the plasma when using repetitive pulsed nanosecond discharges, one of the main strategies used in the field of plasma assisted combustion. Experiments were performed in a counterflow nonpremixed burner with parallel electrodes at the nozzle exits and nanosecond-resolved photography of the plasma emission is presented. It was shown that the discharge development in stratified media may take place in the form of a dielectric barrier discharge with a localized energy deposition. In the experiments presented the discharge energy was coupled to the flame front because of the high rate of chemi-ionization and the gas density decrease in the flame
Multiple Score Comparison: a network meta-analysis approach to comparison and external validation of prognostic scores
BACKGROUND Prediction models and prognostic scores have been increasingly popular in both clinical practice and clinical research settings, for example to aid in risk-based decision making or control for confounding. In many medical fields, a large number of prognostic scores are available, but practitioners may find it difficult to choose between them due to lack of external validation as well as lack of comparisons between them. METHODS Borrowing methodology from network meta-analysis, we describe an approach to Multiple Score Comparison meta-analysis (MSC) which permits concurrent external validation and comparisons of prognostic scores using individual patient data (IPD) arising from a large-scale international collaboration. We describe the challenges in adapting network meta-analysis to the MSC setting, for instance the need to explicitly include correlations between the scores on a cohort level, and how to deal with many multi-score studies. We propose first using IPD to make cohort-level aggregate discrimination or calibration scores, comparing all to a common comparator. Then, standard network meta-analysis techniques can be applied, taking care to consider correlation structures in cohorts with multiple scores. Transitivity, consistency and heterogeneity are also examined. RESULTS We provide a clinical application, comparing prognostic scores for 3-year mortality in patients with chronic obstructive pulmonary disease using data from a large-scale collaborative initiative. We focus on the discriminative properties of the prognostic scores. Our results show clear differences in performance, with ADO and eBODE showing higher discrimination with respect to mortality than other considered scores. The assumptions of transitivity and local and global consistency were not violated. Heterogeneity was small. CONCLUSIONS We applied a network meta-analytic methodology to externally validate and concurrently compare the prognostic properties of clinical scores. Our large-scale external validation indicates that the scores with the best discriminative properties to predict 3 year mortality in patients with COPD are ADO and eBODE
Acid digestion for cadmium determination in mineral salt mixing for animal nutrition by thermospra y flame furnace Atomic absorption spectrometry.
Cadmium was determined in a sample of mineral salt mixing to milk cattle that has been preparing to be a reference material. A volume of 3 mL of HNO3 3.0 mol L-1 plus 2.0 of H202 30% (W w-1) was added to 250 mg of sample in a cavity microwave oven. After digestion performance the volume was adjusted to 10 mL with water, centrifuged and the supernatant determined by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). The system consist of a peristaltic pump, a lab-made commutator injector, and the thermospray flame furnace unit, which includes the ceramic capillary (0.5 mm 10,2.0 mm ED and 100 mm of length) and the Ni tube (10 cm) which is located on the AAS burner. For reaching a higher temperature inside the tube, six holes of 2 mm diameter were drilled in the bottom of the tube. Another orifice was drilled at 90' to the bottom holes for inserting the thermospray capillary. The capillary tip is about 1 mm inside the tube furnace. The manifold was assembled with 0.5 mm i.d. PTFE tubing, sample volume of 1 00 uL, 0.5 mL min-1 of flow rate, and 0.5 % (w v-1) EDTA plus 0.1 % (v v-1) Triton X 100 as carrier stream. Limits of detection (LOD) and quantification (LOQ) 'obtained were 0.31~g L-1 and 1.02~gL-1, respectively. The obtained results were 402 +- 35ug L-1. The accuracy was checked by performing GFAAS (465 +-95ug L-1) and the results proved to be similar by using t test. The high rsd in the GFAAS was probably due the high chloride sample amount
- âŠ