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Automated generation of computationally hard feature models using evolutionary algorithms
This is the post-print version of the final paper published in Expert Systems with Applications. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2014 Elsevier B.V.A feature model is a compact representation of the products of a software product line. The automated extraction of information from feature models is a thriving topic involving numerous analysis operations, techniques and tools. Performance evaluations in this domain mainly rely on the use of random feature models. However, these only provide a rough idea of the behaviour of the tools with average problems and are not sufficient to reveal their real strengths and weaknesses. In this article, we propose to model the problem of finding computationally hard feature models as an optimization problem and we solve it using a novel evolutionary algorithm for optimized feature models (ETHOM). Given a tool and an analysis operation, ETHOM generates input models of a predefined size maximizing aspects such as the execution time or the memory consumption of the tool when performing the operation over the model. This allows users and developers to know the performance of tools in pessimistic cases providing a better idea of their real power and revealing performance bugs. Experiments using ETHOM on a number of analyses and tools have successfully identified models producing much longer executions times and higher memory consumption than those obtained with random models of identical or even larger size.European Commission (FEDER), the Spanish Government and
the Andalusian Government
A glossary for the social epidemiology of work organization. Part 3: terms from labour markets
This is part 3 of a three-part glossary on the
social epidemiology of work organisation. The
first two parts deal with the social psychology
of work and with organisations. This concluding
part presents concepts related to labour markets.
These concepts are drawn from economics, business
and sociology. They relate both to traditional
interests in these disciplines and to contemporary
ideas on post-industrialisation and globalisation,
particularly the growth of employment in service
industries, the development of a 24-h economy,
increased participation of the female labour force
and the perceived needs of employers in emerging
high-tech economies.These changes are of
particular interest because they are linked to
increasing inequality in earnings and changes in
social relationships in employment. These concepts
have the potential to elucidate the pathways
through which health is affected by conditions of
work as an underlying cause
Psychosocial factors and work related sickness absence among permanent and non-permanent employees
Study objective: To examine the association between psychosocial work factors and work related sickness absence among permanent and non-permanent employees by sex.Design: A cross sectional survey conducted in 2000 of a representative sample of the European Union total active population, aged 15 years and older. The independent variables were psychological job demands and job control as measures of psychosocial work environment, and work related sickness absence as the main outcome. Poisson regression models were used to compute sickness absence days' rate ratios.Setting: 15 countries of the European Union.Participants: A sample of permanent (n=12875) and non-permanent (n=1203) workers from the Third European Survey on Working Conditions.Results: High psychological job demands, low job control, and high strain and passive work were associated with higher work related sickness absence. The risks were more pronounced in non-permanent compared with permanent employees and men compared with women.Conclusions: This work extends previous research on employment contracts and sickness absence, suggesting different effects depending on psychosocial working conditions and sex
How to Complete an Interactive Configuration Process?
When configuring customizable software, it is useful to provide interactive
tool-support that ensures that the configuration does not breach given
constraints.
But, when is a configuration complete and how can the tool help the user to
complete it?
We formalize this problem and relate it to concepts from non-monotonic
reasoning well researched in Artificial Intelligence. The results are
interesting for both practitioners and theoreticians. Practitioners will find a
technique facilitating an interactive configuration process and experiments
supporting feasibility of the approach. Theoreticians will find links between
well-known formal concepts and a concrete practical application.Comment: to appear in SOFSEM 201
The Economic Value of Basin Protection to Improve the Quality and Reliability of Potable Water Supply: Some Evidence from Ecuador
This study estimates the willingness to pay (WTP) of Loja’s households to protect two micro-basins that supply over 40 percent of potable water to the city. Results indicate that households have an average WTP of $5.80 per month, which corresponds to a 25 percent increase in the self-reported monthly water bill, to preserve the basins.Basin protection, contingent valuation, Loja, Ecuador, Environmental Economics and Policy, Land Economics/Use,
Pattern formation in a predator-prey system characterized by a spatial scale of interaction
We describe pattern formation in ecological systems using a version of the
classical Lotka-Volterra model characterized by a spatial scale which controls
the predator-prey interaction range. Analytical and simulational results show
that patterns can emerge in some regions of the parameters space where the
instability is driven by the range of the interaction. The individual-based
implementation captures realistic ecological features. In fact, spatial
structures emerge in an erratic oscillatory regime which can contemplate
predators' extinction.Comment: 5 pages, 4 figure
Extended-spectrum beta-lactamases-producing <i>Escherichia coli</i> in common vampire bats <i>Desmodus rotundus</i> and livestock in Peru
Antibiotic resistance mediated by bacterial production of extended‐spectrum beta‐lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital‐acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL‐producing bacteria. Only limited data are available on the circulation of ESBL‐producing bacteria in animals. Here, we report ESBL‐producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of blaCTX‐M‐15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resistance that were not always host species‐specific, suggesting sharing of strains between species or infection from a common source. This study shows widespread ESBL resistance in wild and domestic animals, supporting animal communities as a potential source of resistance. Future work is needed to elucidate the role of bats in the dissemination of antibiotic‐resistant strains of public health importance and to understand the origin of the observed resistance
Evaluación del Bioinsumo de Fique Pulverizado (Furcraea spp) para el Control in vitro de Phytophthora infestans en papa (Solanum tuberosum L)
The objective of this research was evaluating the antifungal activity of spray-dried Fique (Furcraea spp) for in vitro control of Phytophthora infestans in potatoes (Solanum tuberosum L). The optimal drying process variables studied were the entry temperature and air velocity of 140 °C and 60 m/s. The product obtained was amended in an agar medium tomato which was placed in petri containers, inoculated with 1.2 cm in diameter of pathogens discs. The optimum treatment inhibited 100% growth of the pathogen. Also, a reduction of water activity of 37.4% was achieved. This allowed increasing its preservation. The results showed that the technique is highly favorable for the conservation of bio-products of fungal properties
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