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A tale of one city: intra-institutional variations in migrating VLE platform
City University London committed in 2009 to make Moodle the Virtual Learning Environment (VLE) at the core of a new Strategic Learning Environment (SLE) comprised of VLE, externally facing website and related systems such as video streaming and virtual classrooms. Previously, the WebCT VLE had been separate from most of the other systems at the institution with very limited connections to other tools. Each of the schools within the institution was able to pursue their own strategy and timeframe for the migration and embedding of Moodle within their subject areas, within an absolute limit of 2 years. This paper outlines the approaches taken by the various schools, highlighting similarities and differences, and draws out common aspects from the project to make recommendations for institutions seeking to undertake similar migrations
Enhancing Parallel Cooperative Trajectory Based Metaheuristics with Path Relinking
This paper proposes a novel algorithm combining path relinking with a set of cooperating trajectory based parallel algorithms to yield a new metaheuristic of enhanced search features. Algorithms based on the exploration of the neighborhood of a single solution, like simulated annealing (SA), have offered accurate results for a large number of real-world problems in the past. Because of their trajectory based nature, some advanced models such as the cooperative one are competitive in academic problems, but still show many limitations in addressing large scale instances. In addition, the field of parallel models for trajectory methods has not deeply been studied yet (at least in comparison with parallel population based models). In this work, we propose a new hybrid algorithm which improves cooperative single solution techniques by using path relinking, allowing both to reduce the global execution time and to improve the efficacy of the method. We test here this new model using a large benchmark of instances of two well-known NP-hard problems: MAXSAT and QAP, with competitive results.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
Predicting the locations of possible long-lived low-mass first stars: Importance of satellite dwarf galaxies
The search for metal-free stars has so far been unsuccessful, proving that if
there are surviving stars from the first generation, they are rare, they have
been polluted, or we have been looking in the wrong place. To predict the
likely location of Population~III (Pop~III) survivors, we semi-analytically
model early star formation in progenitors of Milky Way-like galaxies and their
environments. We base our model on merger trees from the high-resolution dark
matter only simulation suite \textit{Caterpillar}. Radiative and chemical
feedback are taken into account self-consistently, based on the spatial
distribution of the haloes. Our results are consistent with the non-detection
of Pop III survivors in the Milky Way today. We find that possible surviving
Population III stars are more common in Milky Way satellites than in the main
Galaxy. In particular, low mass Milky Way satellites contain a much larger
fraction of Pop~III stars than the Milky Way. Such nearby, low mass Milky Way
satellites are promising targets for future attempts to find Pop~III survivors,
especially for high-resolution, high signal-to-noise spectroscopic
observations. We provide the probabilities for finding a Pop~III survivor in
the red giant branch phase for all known Milky Way satellites to guide future
observations.Comment: 17 pages, 12 figures, 1 table, submitted to MNRA
Direct observation of substitutional Ga after ion implantation in Ge by means of extended x-ray absorption fine structure
We present an experimental lattice location study of Ga atoms in Ge after ion implantation at elevated temperature (250°C). Using extended x-rayabsorption fine structure (EXAFS) experiments and a dedicated sample preparation method, we have studied the lattice location of Ga atoms in Ge with a concentration ranging from 0.5 at. % down to 0.005 at. %. At Ga concentrations ≤0.05 at.%, all Ga dopants are substitutional directly after ion implantation, without the need for post-implantation thermal annealing. At higher Ga concentrations, a reduction in the EXAFS amplitude is observed, indicating that a fraction of the Ga atoms is located in a defective environment. The local strain induced by the Ga atoms in the Ge matrix is independent of the Ga concentration and extends only to the first nearest neighbor Ge shell, where a 1% contraction in bond length has been measured, in agreement with density functional theory calculations.We acknowledge the support from the Research Foundation
Flanders, the epi-team from imec, the KU Leuven
GOA 09/06 project, the IUAP program P6/42 and the Australian
Research Council. S.C. acknowledges support from
OCAS NV by an OCAS-endowed chair at Ghent University
The Status of Utah\u27s Agriculture and its Contribution to the State Economy
Growth in agricultural productivity and the migration of labor from agriculture to other employment has been a source of growth for the whole economy. From the times of pioneer settlement in Utah, more than 130 years ago, agricultural production has declined as a proportion of total economic activity. Employment, personal income, gross sales, and other measures can be shown to have declined as a proportion of the totals of these measures for the state. Yet, it is this very decline in dependence on workers producing food that has helped the economy to grow in size and variety both in Utah and throughout the nation
The Evolution of Anodic Hydrogen on High Purity Magnesium in Acidic Buffer Solution
Hydrogen evolution (HE) on anodically polarized Mg, commonly referred to as Negative Difference Effect, was studied by galvanodynamic measurements coupled with real-time gravimetric H2 volume collection, the Scanning Vibrating Electrode Technique and potentiodynamic polarization experiments. High purity Mg (99.96% Mg) electrodes were studied in chloride-free 0.1 M citric acid solution buffered at pH with the aim of determining the source of anodic HE and the role of the corrosion film on the process. In such conditions of pH, the typical dark corrosion product exhibited in neutral and alkaline solutions was not found but the HE rate still increased with increasing potential. Evidence that HE on dissolving high purity Mg is associated with the regions dominated by the anodic dissolution reaction is provided. The role of noble impurity enrichment on the electrode surface during anodic polarization and the effect of Fe re-deposition are also discussed
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