2,253 research outputs found

    An Empirical Study of Real-World SPARQL Queries

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    Understanding how users tailor their SPARQL queries is crucial when designing query evaluation engines or fine-tuning RDF stores with performance in mind. In this paper we analyze 3 million real-world SPARQL queries extracted from logs of the DBPedia and SWDF public endpoints. We aim at finding which are the most used language elements both from syntactical and structural perspectives, paying special attention to triple patterns and joins, since they are indeed some of the most expensive SPARQL operations at evaluation phase. We have determined that most of the queries are simple and include few triple patterns and joins, being Subject-Subject, Subject-Object and Object-Object the most common join types. The graph patterns are usually star-shaped and despite triple pattern chains exist, they are generally short.Comment: 1st International Workshop on Usage Analysis and the Web of Data (USEWOD2011) in the 20th International World Wide Web Conference (WWW2011), Hyderabad, India, March 28th, 201

    Performance analysis of persistence technologies for cloud repositories of models

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    The growing adoption of Model Driven Development (MDD) in companies during last decade arises some model interchange problems. Companies need support to interchange models and reuse parts of them for developing new projects. Traditional tools for model edition and model interchange have different performance issues related to the models storage. There are mainly two styles to organize the persistence of models into repositories: a complex and large model or a large amount of small models. This last approach is common in companies that generate software from models. In this paper, we analyse performance properties of different persistence technologies to store small/medium-scale models, the analysis results should be considered in the design of model repositories in the cloud. With this aim, we have designed and developed a generic architecture to evaluate each persistence technology under similar situations

    Impact of Dynamic Capabilities on Customer Satisfaction through Digital Transformation in the Automotive Sector

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    Technology has impacted businesses in different areas, and, consequently, many companies have found it necessary to make changes in their structures and business models to improve customer satisfaction. The objective was to quantify the effect of dynamic capabilities on customer satisfaction, through digital transformation within the automotive sector. A random sample of 42 questionnaires on 127 surveyed industries was collected during the period 2019–2020 in a pre-COVID-19 context. A structural equation model (SEM) in two stages was applied. In the first stage, two reflective models were built. In a second stage, a structural equation model was evaluated. The results obtained in this study showed that the capabilities of sensing, seizing and innovation were suitably grouped in a construct called “Dynamic Capabilities”. A positive influence of Dynamic Capabilities on customer satisfaction was found. Therefore, the companies in this industry should focus on developing dynamic capabilities to improve customer satisfaction. Once the opportunities have been identified, managers take advantage of their potential (seizing) to transform and exploit knowledge in the creation, innovation, process improvement, and definition of strategies to combine new knowledge with that already existing. The digital transformation has contributed to identify the real needs for customers, to contact them and solve their problems, as well as offering products and services by anticipating their needs

    LOS DESAFÍOS DE LA ÉTICA AMBIENTAL

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    En 1968 Raquel Carson comenzaba una revolución en el pensamiento, quizá una de las de mayor peso en la actualidad. En su libro "La primavera silenciosa" acusaba del deterioro ambiental al poder ilimitado del ser humano. La creencia surgida en la modernidad de que todo lo que el hombre decidía era en sí mismo lo mejor por haber sido fruto de una voluntad libérrima, daba primacía y legitimidad absoluta a su acción sobre la naturaleza. Surgieron con gran fuerza numerosos grupos ecologistas que adoptaron un pensamiento que responde al nombre de "ecología profunda" o "Deep Ecology" descrito por primera vez por Arme Naess en un artículo publicado por la revista Inquiry y titulado "The Shallow and the Deep, Long Range Ecology Movement". Los principios que proponía este movimiento (Naess 1984) pueden ser resumidos en ocho grandes puntos: 1) la vida de los seres no humanos es un valor en sí: 2) la riqueza y la diversidad de estas formas de vida son también valores en sí; 3) los seres humanos no pueden intervenir de manera destructiva en la vida; 4) a este respecto, la intervención humana actual es eminentemente excesiva; 5) por consiguiente, las reglas de juego deben ser radicalmente modificadas; 6) esta modificación radical debe hacerse tanto a nivel de las estructuras económicas como de las estructuras ideológicas y culturales; 7) a nivel ideológico, el cambio principal consiste en apreciar más la calidad de la vida que el goce de los bienes materiales; 8) las personas que acepten estos principios tienen la obligación de contribuir, directa o indirectamente a la realización de los cambios fundamentales que aquellos implican

    miraQA: Initial experiments in Question Answering

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    We present the miraQA system that constitutes MIRACLE first experience in Question Answering for monolingual Spanish and has been developed for QA@CLEF 2004. The architecture of the system is described and details of our approach to Statistical Answer Extraction based on Hidden Markov Models are presented. One run that uses last year question set for training purposes has been submitted. The results are presented together with ideas for improvement

    A new pterosaur tarcksite from the Upper Cretaceous Candeleros Formation, Neuquén Province, Patagonia, Argentina

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    New pterosaur tracks from the Aguada de Tuco tracksite of the Cenomanian Candeleros Formation (Neuquén Basin, Argentina) are reported here. They are preserved in medium grain-sized sandstones from fluvial deposits and are associated with Arenicolites isp. The pterosaur tracks are preserved as concave and convex epirelief, as true tracks and natural casts, respectively. The manus impressions, which are the most abundant, are usually isolated, although manus-pes sets and sequences of manus-manus imprints, some of them probably representing trackways, have been also documented. The best-preserved manus tracks (average 10.8 cm long, 5.4 cm wide) are tridactyl and strongly asymmetrical. The pes tracks (average 11.5 cm long, 4.8 cm wide) are very elongated, trapezoidal to subtriangular, and generally preserve three-digit impressions. Some morphological track variabilities, such as elongated impressions of manus digit III, has been interpreted as the result of variations in substrate properties, mainly moisture content, and behavior. The main features of the studied tracks, manus and pes track morphologies and length/width ratios, are similar to those of the Pteraichnus ichnogenus. Nevertheless, due to their preservation, not optimal, we classify them as cf. Pteraichnus isp. Only other site with pterosaur tracks has been found in the early Late Cretaceous of South America. These tracks are also in the Candeleros Formation but differ from the Aguada de Tuco ones in having differences in divarication of manus digit impressions, among other features. The present study contributes to the knowledge of the poorly pterosaur track record from Gondwana and its ichnotaxonomic and paleoecological implications.Fil: Heredia, Arturo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Díaz Martínez, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaFil: Pazos, Pablo Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: de Valais, Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación en Paleobiología y Geología; ArgentinaXII Congreso de la Asociación Paleontológica ArgentinaBuenos AiresArgentinaAsociación Paleontológica Argentin

    MIRACLE’s hybrid approach to bilingual and monolingual Information Retrieval

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    The main goal of the bilingual and monolingual participation of the MIRACLE team at CLEF 2004 was testing the effect of combination approaches to information retrieval. The starting point is a set of basic components: stemming, transformation, filtering, generation of n-grams, weighting and relevance feedback. Some of these basic components are used in different combinations and order of application for document indexing and for query processing. Besides this, a second order combination is done, mainly by averaging or by selective combination of the documents retrieved by different approaches for a particular query

    Polymer [Pd(CH2SO2C6H4Me)2]n, a precursor to remarkably stable Pd organometallics

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    Producción CientíficaA polymer [Pd(CH2SO2C6H4Me)2]n is obtained by thermolysis of cis-[Pd(CH2SO2C6H4Me)2(NCMe)2] to release the MeCN ligands. The corresponding coordination sites are then occupied by weak Pd–O bonds, easier to break than the previous Pd–N bonds. This allows us to produce from the polymer cis complexes containing ligands weaker than NCMe, such as acetone or water. The complexes cis-[Pd(CH2SO2C6H4Me)2{OC(CD3)2}2], cis-[Pd(CH2SO2C6H4Me)2(OH2)2], and cis-[Pd(CH2SO2C6H4Me)2(OH2){OC(CD3)2}], and cyclic dimers [Pd(CH2SO2C6H4Me)2(OH2)]2 with bridging methylsulphone groups are formed. The Pd : PPh3 : OH2 1 : 1 : 1 reaction of the polymer produces cis-[Pd(CH2SO2C6H4Me)2(OH2)(PPh3)], which isomerizes to trans-[Pd(CH2SO2C6H4Me)2(OH2)(PPh3)], with water O-coordinated to Pd and making hydrogen bonds to the two SO2 groups as seen in its X-ray structure. A similar role is played by RNH2 groups in the structures of trans-[Pd(CH2SO2C6H4Me)2(NH3)(PPh3)] and the dimer μ-(N2H4)(trans-[Pd(CH2SO2C6H4Me)2(PPh3)])2. In addition to these interesting intramolecular hydrogen bonding properties provided by the SO2 groups, the structural and 1H NMR data available suggest that the CH2SO2C6H4Me group is an interesting kind of strong alkyl σ donor, with high trans influence, and forms very stable Pd complexes extraordinarily resistant to reductive elimination and to hydrolysis by water at room temperature.2018-08-08Ministerio de Economía, Industria y Competitividad (Projects CTQ2014-52796-P and CTQ2016-80913-P)Junta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. VA256U13; UIC 176

    GeoBotánica: Aplicación Web para la visualización, análisis y estudio de taxones vegetales. Caso de estudio Cuenca Media del Tajo.

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    La geobotánica (fitogeografía), rama de la biogeografía, estudia cómo la tectónica de placas y las orogénesis determinan una distribución de tierras, mares y accidentes geográficos, el aislamiento o la conexión de poblaciones, la distribución espacial de las especies y los fenómenos de especialización. La corología, por su parte, se ocupa de la distribución geográfica de cada especie, siendo el clima y el suelo los principales factores que influyen en la misma. Como resumen podemos decir que para la geobotánica es de interés poder obtener y analizar: mapas corológicos, los factores limitantes climáticos y químicos, y la relación con el medio y otras especies. El objetivo de la aplicación Web desarrollada, basada en estándares OGC para el acceso y visualización de información geográfica, es dotar a los geobotánicos de una herramienta sencilla y accesible en Web, que ayude en los procesos de estudio y análisis de la distribución de especies vegetales en el territorio y sus condicionantes. La aplicación, desarrollada a partir de los datos del inventario botánico del profesor Martínez Labarga de la cuenca media del Tajo, permite realizar estudios y análisis geobotánicos, apoyándose en la confección de mapas corológicos y la correlación de la distribución de cada especie con las magnitudes climáticas de temperatura o precipitación y las características de los suelos sobre los que aparece. Esta aplicación dispone de una arquitectura de 3 capas (almacenes de datos, servicios y clientes) y ha sido desarrollada con tecnologías OpenSource (PostGIS, Geoserver, Apache httpd, OpenLayers, GeoExt, php) y consume datos propios publicados mediante estándares OGC (WMS y WFS) y capas de la IDE tanto de suelos (litológico, geológico, topográfico, ortoimágenes) como climáticos (precipitaciones y temperaturas ?CREAF). El desarrollo de la aplicación y la prueba de concepto han permitido identificar algunos problemas de rendimiento a la hora de realizar consultas al Atlas Climático de la Península Ibérica y se ha propuesto una solución basada en el cacheado de datos consultados en tiempo de ejecució
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