4,076 research outputs found
An Empirical Study of Real-World SPARQL Queries
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
Revealed Comparative Advantage and Competitiveness in Pear
This article focuses on the study of the comparative advantages and competitiveness in the global pear market. First, it will outline a clear distinction between these two concepts, followed by analysis. This paper provides a new index of competitiveness developed by our research based on the insights offered by a wide range of studies on this subject. The aim is to achieve a new line of analysis to improve and expand the possibilities of present day studies
Análisis de los ciclos de congelación y descongelación en la capa activa en el entorno de la BAE JCI. Periodo 2000-2011
Close to the Spanish Antarctic Station our research team drilled, at the 1999-2000 Antarctic campaign, a 2,30 m shallow
borehole in quartzite bedrock. This borehole was instrumented with temperature data loggers (Tinytag model) that have
allowed us to register the gradient thermal in a continuous regime evolution during the 2000-2011 period. The analysis of
the temperature data allows to describe the temporal evolution of the freezing and thawing cycles in the active layer, as
well as the N-Factor variability, related with the soil surface thermal behavior and its energy balance. In this work we
discuss the different freezing and thawing mechanisms in monthly and annual periods. The study shows a important
freezing and thawing inter annual variability,, the annual cumulative index showed values in the following intervals:
freezing index (-700, -300 ºC day) and thawing index (400, 700 ºC day)
An Occupational Therapy Approach to Sexuality in People with Acquired Brain Injury in a Subacute Setting
This is a post-peer-review, pre-copyedit version of an article published in Sexuality and Disability. The final authenticated version is available online at Srpinger Link[Abstract] To analyze if people with acquired brain injury in sub-acute situation, as well as their relatives and/or partners, consider relevant the approach to sexuality during their Occupational Therapy intervention. This study presents a qualitative design with a phenomenological approach. Twelve participants were interviewed: eight people with acquired brain injury, two relatives and two partners who agreed to participate. The information has been collected through interviews. According to the interviews, the following categories have emerged: changes and everyday life, the taboo of sex and its relation to gender and the relevance of counselling. Participants consider sexuality as another activity of daily living, which has been modified due to acquired brain injury. Not only does the taboo of sex condition the subject, but it is also influenced by the individual’s gender. In addition, the counselling by the professionals involved in the rehabilitation process is the main intervention claimed by the participants of this study. The participants consider sexuality as an activity of daily living. Therefore, the occupational therapist who follows the holistic conception of the people must consider sexuality in the intervention process
Perceived match between own and observed models' bodies: influence of face, viewpoints, and body size
People are generally unable to accurately determine their own body measurements and to translate this knowledge to identifying a model/avatar that best represents their own body. This inability has not only been related to health problems (e.g. anorexia nervosa), but has important practical implications as well (e.g. online retail). Here we aimed to investigate the influence of three basic visual features—face presence, amount of viewpoints, and observed model size—on the perceived match between own and observed models' bodies and on attitudes towards these models. Models were real-life models (Experiment 1) or avatar models based on participants' own bodies (Experiment 2). Results in both experiments showed a strong effect of model size, irrespective of participants' own body measurements. When models were randomly presented one by one, participants gave significantly higher ratings to smaller- compared to bigger-sized models. The reverse was true, however, when participants observed and compared models freely, suggesting that the mode of presentation affected participants' judgments. Limited evidence was found for an effect of facial presence or amount of viewpoints. These results add evidence to research on visual features affecting the ability to match observed bodies with own body image, which has biological, clinical, and practical implications.ATJ and LDC were supported by Ministerio de Economía, Industria y Competitividad of Spain Ramón y Cajal Grant RYC-2014-15421. LDC was also supported by Ministerio de Ciencia, Innovación y Universidades Juan de la Cierva-Incorporación Grant IJC2018-038347-I
Improving reliability estimation in cognitive diagnosis modeling
Cognitive diagnosis models (CDMs) are used in educational, clinical, or personnel selection settings to classify respondents with respect to discrete attributes, identifying strengths and needs, and thus allowing to provide tailored training/treatment. As in any assessment, an accurate reliability estimation is crucial for valid score interpretations. In this sense, most CDM reliability indices are based on the posterior probabilities of the estimated attribute profiles. These posteriors are traditionally computed using point estimates for the model parameters as approximations to their populational values. If the uncertainty around these parameters is unaccounted for, the posteriors may be overly peaked, deriving into overestimated reliabilities. This article presents a multiple imputation (MI) procedure to integrate out the model parameters in the estimation of the posterior distributions, thus correcting the reliability estimation. A simulation study was conducted to compare the MI procedure with the traditional reliability estimation. Five factors were manipulated: the attribute structure, the CDM model (DINA and G-DINA), test length, sample size, and item quality. Additionally, an illustration using the Examination for the Certificate of Proficiency in English data was analyzed. The effect of sample size was studied by sampling subsets of subjects from the complete data. In both studies, the traditional reliability estimation systematically provided overestimated reliabilities, whereas the MI procedure offered more accurate results. Accordingly, practitioners in small educational or clinical settings should be aware that the reliability estimation using model parameter point estimates may be positively biased. R codes for the MI procedure are made availableOpen Access funding provided thanks to the CRUE-CSIC
agreement with Springer Nature. This work has been funded by the
Community of Madrid through the Pluriannual Agreement with the
Universidad de Universidad Autónoma de Madrid in its Programa
de Estímulo a la Investigación de Jóvenes Doctores (Reference SI3/
PJI/2021-00258), and by the Spanish Ministry of Science and Innovation (FPI BES-2016-077814
Effect of Sn content on Pt/ CNT electrocatalysts for direct ethanol fuel cell application
Several bimetallic PtSn catalysts supported on multiwalled carbon nanotubes for ethanol electro-oxidation were prepared by conventional impregnation-reduction method. The Pt loading was kept at 20 wt.% and Pt:Sn atomic ratios of 5:1, 3:1, and 1:1 were selected. The catalysts were structurally characterized by temperature programmed reduction, X-ray diffraction, X-ray photoelectron spectroscopy, H2 chemisorption, cyclohexane dehydrogenation reaction, and transmission electron microscopy. The electrochemical characterization of the electrocatalytic materials was carried out in acid medium by cyclic voltammetry, linear sweep voltammetry, chronoamperometry, and CO stripping techniques. Among the different stoichiometries tested, the Pt(20)Sn(12.17)/CNT catalyst exhibited the highest electrocatalytic activity for ethanol oxidation reaction, with mass current density of 189.5 mA mgPt−1 at 796 mV (vs. Ag/AgCl).Fil: Azcoaga Chort, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Nagel, Pablo A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Veizaga, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Rodriguez, Virginia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin
The effect of bending on laser-cut electro-textile inductors and capacitors attached on denim as wearable structures
In this paper we present the design, fabrication and characterization of electro-textile inductor and capacitor patterns on denim fabric as a basis for the development of wearable e-textiles. Planar coil inductors have been harnessed as antenna structures for the development of Near Field Communication (NFC) tags with temperature sensing capability, while interdigitated electrode (IDE) capacitors have been used as humidity sensors for wearable applications. The effect of bending in the electrical performance of such structures was evaluated, showing variations below 5% in both inductance and capacitance values for bending angles in the range of interest, i.e. those fitting to human limbs. In the case of the fabricated NFC tags, a shift in the resonance frequency below 1.7% was found, meaning that the e-textile tag would still be readable by an NFC- enabled smartphone. In respect of the capacitive humidity sensor, we obtained a minimum capacitance variation of 40% for a relative humidity range from 10% to 90%. Measured thermal shift was below 5% in the range from 10 to 40oC. When compared to the 4% variation due to bending, it can be concluded that this capacitive structure can be harnessed as humidity sensor even under bending strain conditions and moderate temperature variations. The development and characterization of such structures on denim fabrics, which is one of the most popular fabrics for everyday clothing, combined with the additional advantage of affordable and easy fabrication methodologies, means a further step towards the next generation of smart e-textile products
IAA : Información y actualidad astronómica (46)
Sumario: UPWARDS: ciencia nueva para un planeta viejo.--
La teoría del estado estacionario.--
Sorpresas en la nebulosa del Huevo Podrido.--
DECONSTRUCCIÓN Y otros ENSAYOS. Binarias de rayos X.--
Homenaje a Javier Gorosabel.--
EL “MOBY DICK” DE... Christina Thöne (IAA).--
CIENCIA EN HISTORIAS...Maria Mitchell.--
ACTUALIDAD.--
SALA LIMPIA.--
CIENCIA: PILARES E INCERTIDUMBRES. Mercurio.N
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