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

Accretion of galaxy groups into galaxy clusters

We study the role of group infall in the assembly and dynamics of galaxy clusters in ΛCDM. We select 10 clusters with virial mass M200 ∼1014 M from the cosmological hydrodynamical simulation Illustris and follow their galaxies with stellar mass M⊙ ≥ 1.5 × 108 M. A median of ∼38% of surviving galaxies at z = 0 is accreted as part of groups and did not infall directly from the field, albeit with significant cluster-to-cluster scatter. The evolution of these galaxy associations is quick, with observational signatures of their common origin eroding rapidly in 1-3 Gyr after infall. Substructure plays a dominant role in fostering the conditions for galaxy mergers to happen, even within the cluster environment. Integrated over time, we identify (per cluster) an average of 17 ± 9 mergers that occur in infalling galaxy associations, of which 7 ± 3 occur well within the virial radius of their cluster hosts. The number of mergers shows large dispersion from cluster to cluster, with our most massive system having 42 mergers above our mass cut-off. These mergers, which are typically gas rich for dwarfs and a combination of gas rich and gas poor for M⊙ ∼1011 $m M_odot$, may contribute significantly within ΛCDM to the formation of specific morphologies, such as lenticulars (S0) and blue compact dwarfs in groups and clusters.Fil: Benavides, José A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Sales, Laura Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentina. University of California; Estados UnidosFil: Abadi, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; Argentin

FaMa-OVM: a Tool for the Automated Analysis of Ovms

Orthogonal Variability Model (OVM) is a modelling language for representing variability in Software Product Line Engineering. The automated analysis of OVMs is defined as the computer-aided extraction of information from such models. in this paper, we present FaMa-OVM, which is a pioneer tool for the automated analysis of OVMs. FaMa-OVM is easy to extend or integrate in other tools. It has been developed as part of the FaMa ecosystem enabling the benefits coming from other tools of that ecosystem as FaMaFW and BeTTy

UCO.MIPSIM: pipelined computer simulator for teaching purposes

Since pipelining is a very important implementation technique for processors, students in Computer Science need to achieve a good understanding of it. UCO.MIPSIM simulator has been developed to support teaching such concepts. This paper introduces the basics of pipelining and describes UCO.MIPSIM, its main components and its functions. The learning effectiveness of the simulator has been tested by means of the comparison with two learning tools, the traditional paper and pencil and another pipelined computer simulator. In this way, a tool evaluation methodology is also introduce

Physical Wigner functions

In spite of their potential usefulness, the characterizations of Wigner functions for Bose and Fermi statistics given by O'Connell and Wigner himself almost thirty years ago has drawn little attention. With an eye towards applications in quantum chemistry, we revisit and reformulate them in a more convenient way.Comment: Latex, 10 page

A Variability-Based Testing Approach for Synthesizing Video Sequences

A key problem when developing video processing software is the di culty to test di erent input combinations. In this paper, we present VANE, a variability-based testing approach to derive video sequence variants. The ideas of VANE are i) to encode in a variability model what can vary within a video sequence; ii) to exploit the variability model to generate testable con gurations; iii) to synthesize variants of video sequences corresponding to con gurations. VANE computes T-wise covering sets while optimizing a function over attributes. Also, we present a preliminary validation of the scalability and practicality of VANE in the context of an industrial project involving the test of video processing algorithms.Ministerio de Economía y Competitividad TIN2012-32273Junta de Andalucía TIC-5906Junta de Andalucía P12-TIC-186

Scoping Review About Working Conditions and Health of Immigrant Workers in Spain

Fundamentos: La relación entre inmigración, trabajo y salud constituye uno de los retos más importantes en salud laboral y más concretamente en España por el importante incremento de proporción inmigrante acontecido en el mercado laboral. El objetivo de esta investigación es conocer la relación entre las condiciones de trabajo y sus efectos en la salud de trabajadores inmigrantes en España. Métodos: Revisión bibliográfica de artículos científicos originales en español e inglés Medline y Medes (1998-2012). Se revisaron los textos completos de los artículos incluidos. Resultados: Se incluyeron 20 estudios, 13 con metodología de investigación cuantitativa y 7 cualitativa. Los temas tratados abordaban problemas específicos de salud relacionados con el trabajo (principalmente lesiones por accidente de trabajo), incapacidad laboral y diferencias en condiciones de trabajo y empleo. Los hallazgos de los estudios mostraron mayor incidencia de lesiones por accidentes de trabajo, menores tasas de incapacidad laboral, mayor prevalencia de presentismo laboral, exposición a factores psicosociales y precariedad laboral en la población inmigrante. Conclusiones: A pesar de la singularidad del proceso demográfico migratorio, los problemas de salud y determinantes identificados no difieren de los referenciados en otros países, en otros contextos y en otros momentos.Background:The relationship between immigration, work, and health is one of the most important challenges in occupational health at current, particularly in Spain, by the significant increase in the migrant workers in the labor market occurred. This investigation aims to know the relationship betwen working conditions and their effects on migrant workers. Methods: Scoping review of scientific papers on this topic at the Medline and Medes databases in Spanish and English (1998-2012). The articles included were full text reviewed. Results: 20 studies were included, 13 with quantitative methodology and 7 qualitative. The topics address specific health problems related to work (primarily occupational accidents), disability, and differences in working conditions and employment. The findings of the studies show a higher incidence of injury accidents, lower rates of disability, higher prevalence of work presenteeism, exposure to psychosocial factors, and precariousness. Conclusion: Despite the uniqueness of the demographic process migration happened in Spain, health problems and determinants identified no different from those referenced in other countries, in other contexts and in other times

ARREGLOS DE SIEMBRA Y FERTILIZACIÓN ORGÁNICA SOBRE EL CRECIMIENTO DEL CEDRO ROSADO DE LA INDIA (Acrocarpus fraxinifolius) EN UNA PLANTACIÓN DE DOS AÑOS EN LA COMARCA LAS MERCEDES, BOACO

La situación actual de algunos productores del país es crítica debido al avance de la frontera agrícola y a los bajos rendimientos de sus cultivos, que trae como consecuencia una deforestación indiscriminada de los recursos forestales. Como alternativa ante esta problemática surge el Cedro Rosado de la India (Acrocarpus fraxinifolius), una especie forestal que puede contribuir a la reforestación y al aprovechamiento sostenible de la explotación maderera. Por tanto, el presente estudio procura aportar información sobre esta especie al evaluar dos densidades de siembra (400 y 625 plantas por hectárea) y cuatro niveles de lombrihumus (0.5, 1.0, 1.5 y 2.0 kilogramos por planta) sobre el crecimiento de A. fraxinifolius de dos años de desarrollo. El estudio se desarrolló a partir de febrero del 2005 en la finca La Cañada, comarca Las Mercedes, departamento de Boaco. Las unidades experimentales muestreadas en los lotes con densidades de siembra establecidas fueron agrupadas en tres bloques y la fertilización fue aplicada en parcelas dentro de cada densidad de siembra, lo que correspondió a un arreglo de parcelas divididas, en las que se evaluaron las variables de crecimiento. Se realizó análisis de varianza (ANDEVA) tuvieron significación estadística en las densidades de siembra; pero sí en la fertilización. Se obtuvieron 7.224 m en altura de planta, 4.584 m en altura del fuste comercial, 0.11 m en el diámetro a la altura del pecho, 0.33 m en el perímetro a la altura del pecho, 35.09 unidades de ramas, 0.0085 m2 de área basal y 0.0422 m3 de volumen. Los factores estudiados resultaron ser independiente. Los mayores valores en variables se alcanzaron con las dosis de lombrihumus y densidad poblacional más alta. La densidad de 625 plantas por hectáreas y 1.5 y 2.0 kilogramos por planta superaron los 30 m3 de madera. Así mismo, el mayor beneficio costo se obtuvo con la densidad de 625 y 0.5 kilogramos de lombrihumus por planta, con una ganancia de 50.27 por cada dólar invertido

Imposters among us: globular cluster kinematics and the halo mass of ultra-diffuse galaxies in clusters

The velocity dispersion of globular clusters (GCs) around ultra-diffuse galaxies (UDGs) in the Virgo cluster spans a wide range, including cases where GC kinematics suggest haloes as massive as (or even more massive than) that of the Milky Way around these faint dwarfs. We analyse the catalogues of GCs derived in post-processing from the TNG50 cosmological simulation to study the GC system kinematics and abundance of simulated UDGs in galaxy groups and clusters. UDGs in this simulation reside exclusively in dwarf-mass haloes with M200 ≲ 1011.2 M⊙. When considering only GCs gravitationally bound to simulated UDGs, we find GCs properties that overlap well with several observational measurements for UDGs. In particular, no bias towards overly massive haloes is inferred from the study of bound GCs, confirming that GCs are good tracers of UDG halo mass. However, we find that contamination by intracluster GCs may, in some cases, substantially increase velocity dispersion estimates when performing projected mock observations of our sample. We caution that targets with less than 10 GC tracers are particularly prone to severe uncertainties. Measuring the stellar kinematics of the host galaxy should help confirm the unusually massive haloes suggested by GC kinematics around some UDGs

Benchwood: Una experiencia de benchmarking para la mejora continua

[ESP] Esta ponencia presenta el trabajo realizado en el proyecto de investigación denominado Benchwood desarrollado por el Grupo de Ingeniería de Organización (GIO) de la Universidad de Vigo, al cual pertenecen los autores, en colaboración con el Clúster de la Madera de Galicia (CMA) y que se enmarca en el Plan Estratégico Operativo de la Madera 2008-2011 de éste. El Clúster de la Madera de Galicia (CMA) nació en 2001 con la finalidad de lograr la unión, cooperación e integración del conjunto de empresas y agentes de la cadena de la madera de la Comunidad Autónoma de Galicia (España), buscando alcanzar una mayor nivel de competitividad en todo el sector, establecer las bases de futuras actuaciones conjuntas, constituir un foro de debate y acción, en el fomento de la cultura maderera gallega y, en general, para la defensa de todos sus intereses. El Clúster reúne actualmente a 60 empresas de la comunidad autónoma gallega, pertenecientes a distintos subsectores de la cadena de la madera: forestal, aserradero, chapa y tablero, pasta y papel, carpintería y mobiliario, adhesivos y barnices y servicios. El volumen de negocio que generan las empresas asociadas al Clúster supone más de 1.500 millones de euros, lo que representa cerca del 70% del total del sector, y dan empleo directo a más de 11.500 trabajadores