11037 research outputs found
Sort by
On properties of the set of awards vectors for a claims problem
No full textWe study the geometric structure of a particular type of nonempty convex polytopes that are the intersection of an n-rectangle with a hyperplane x1 +⋯+ xn = E , E > 0 . This type of polytopes arise naturally when studying, for instance, the set of awards vectors for a claims problem, the core of the game associated with a bankruptcy problem, the core-cover set of a game, or the class of two-bound core games. We explore in detail the geometry of such a polytope and provide explicit expressions to compute its volume and its centroid. In particular, we describe a procedure to compute the average-of-awards rule for a claims problem directly from the
parameters of the problem. We show that computing the average-of-awards rule is #P-complete.Xunta de Galicia | Ref. ED481A 2021/325Agencia Estatal de Investigación | Ref. PID2021-124030NB-C3
Ontologías y representación del conocimiento
No full textMinisterio de Ciencia e Innovación | Ref. FFI2009-0882
Olympism in action to achieve sustainable development goals (SDGs)
No full textEste proyecto de Innovación Educativa tuvo por objetivo formar al alumnado universitario en el diseño y evaluación de proyectos curriculares innovadores que permitan la introducción de valores sociales ligados al deporte olímpico y a los objetivos de desarrollo sostenible mediante una metodología interdisciplinar.
Además, se pretendía que los estudiantes elaboraran diferentes recursos educativos con la finalidad de divulgarlos a la comunidad como medio de concienciación social. La introducción de valores olímpicos en el diseño curricular es de vital importancia para el desarrollo armónico de la personalidad del alumnado. Estos valores facilitarán la creación de actitudes de no discriminación, perseverancia, tolerancia, entre otras, lo que repercutirá en un ambiente social más solidario y sostenible.The objective of this Educational Innovation project was to train university students in the design and evaluation of innovative curricular projects that allow the introduction of social values linked to Olympic sport and sustainable development objectives through an interdisciplinary methodology. In addition, students were expected to develop different educational resources with the aim of disseminating
them to the community as a means of raising social awareness. The introduction of Olympic values in the curriculum design is of vital importance for the harmonious development of students' personalities. These values will facilitate the creation of attitudes of non-discrimination, perseverance, tolerance, among others, which will have an impact on a more supportive and sustainable social environment
Text and image: methodological reflections on the use of the bestiary in the cathedral of Santiago de Compostela
Get PDFEl bestiario es uno de los temas más fascinantes de la escultura románica. Su eclosión entre los siglos XI y XII va ligado a la vocación comunicativa del arte medieval y a la facilidad con la que estas imágenes podían asumir un contenido simbólico y moralizante. A través del ejemplo de la Catedral de Santiago de Compostela y el bestiario esculpido en sus capiteles se analizan las diferentes miradas metodológicas para su estudio ilustrándolas con diversos ejemplos realizados por los sucesivos talleres de escultores que se encargaron de la decoración de la basílica románica. La variedad de fuentes que se encuentran en ocasiones tras estas representaciones hace que las relaciones entre texto e imagen sean, a su vez, también variadas y no se limiten tan sólo a los textos o miniaturas de los bestiarios. De hecho, los sermones del Códice Calixtino, producidos en la sede contemporáneamente a estas imágenes esculpidas, son buenos referentes para ellas. Esto quiere decir que los comitentes de estas obras están trasmitiendo las mismas ideas a través de dos medios: el texto de los sermones que se leían en la catedral durante las celebraciones litúrgicas y las imágenes esculpidas en el interior de esta. Esto hace que, para el caso compostelano, se pueda hablar de un verdadero bestiario homilético.The bestiary is one of the most fascinating themes of Romanesque sculpture. Its emergence between the eleventh and twelfth centuries is linked to the communicative vocation of medieval art and the ease with which these images could assume a symbolic and moralizing content. Through the example of the Cathedral of Santiago de Compostela and the bestiary sculpted in its capitals, the different methodological approaches to their study are analyzed, illustrating them with various examples made by the successive sculptors’ workshops that were in charge of the decoration of the Romanesque Basilica. The variety of sources that are sometimes found behind these representations means that the relationships between text and image are, in turn, also varied and are not limited only to the texts or miniatures of the bestiaries. In fact, the sermons of the Codex Calixtinus, produced at the site at the same time as these sculpted images, are good references for them. This means that the commissioners of these works are transmitting the same ideas through two media: the text of the sermons that were read in the cathedral during the liturgical celebrations and the sculpted images inside the cathedral. This means that, for the case of Compostela, we can refer to a true homiletic bestiar
A Smooth Particle Hydrodynamics discretization for the modelling of free surface flows and rigid body dynamics
Get PDFThis work describes a unified discretization of rigid solids and fluids, allowing for spatially detailed and time-resolved simulations of fluid–solid interaction. The model is based on a Smoothed Particle Hydrodynamics (SPH) discretization of the Navier–Stokes equations and Newton's equations for rigid body dynamics. A δ-SPH term is added to the continuity equation, allowing for an effective interface description. The benchmark case of the buoyancy-driven motion of an unrestricted rigid body allows for experimenting new computational approaches for the more general case of fluid–solid interactions, in the case of solid objects larger than the smallest flow scales. Numerical experiments and analytical solutions are recovered from the literature and compared with the numerical results from the proposed model. Experimental measurements were performed and numerical results are compared, resulting in a wide range study of the fundamental properties of fluid–solid systems. After an investigation on the influence of the stabilizing δ-SPH terms, the model is shown to respect free stream consistency, the correct dynamics of a buoyant body, for a range of positive and negative relative densities and the correct recovery of equilibrium states. This work addresses these topics in an attempt to characterise the presented model with regard to the quality of its solutions and possible limitations.Ministerio de Economía y Competitividad | Ref. BIA2012-38676-C03-03Fundação para a Ciência e a Tecnologia | Ref. SFRH/BD/75478/2010Fundação para a Ciência e a Tecnologia | Ref. PTDC/ECM/117660/2010Xunta de Galici
Tailoring the extraction process and properties of polysaccharides from the lichen Evernia prunastri using natural eutectic solvents following a biorefinery approach
Get PDFNatural eutectic solvents (NaESs) for the valorization of biomass have been gaining interest in recent years. However, almost no study is available on their impact on the physicochemical and mechanical properties of polysaccharides and their plasticizing power during extraction. In this work, microwave-assisted extraction was combined with hydrophilic NaESs to intensify the extraction process of polysaccharides from the lichen
Evernia prunastri
, modifying their mechanical properties to obtain viscoelastic materials. With this integrated extraction/formulation process, the energy consumption and production time were reduced by 35% and 23%, respectively. Four solvent systems, namely, sorbitol : betaine, lactic acid : betaine, glycerol : betaine and oxalic acid : proline, were tested. The maximum polysaccharide extraction yield of 44.31% was obtained with oxalic acid : proline at 100 °C for 5 min. For lactic acid : betaine and glycerol : betaine, the highest yields were reached at 120 °C for 15 min (35.93% and 32.93%, respectively). The type of eutectic solvent chosen had a significant impact on the physicochemical and mechanical properties of the extracted polysaccharides. With glycerol : betaine, polysaccharides with higher molecular weights were obtained. Directly drying after the extraction, a flexible material was obtained, exhibiting elastic behavior under deformation, with a Young's modulus of 20.6 MPa and a maximum deformation of 94%. With lactic acid : betaine, a material exhibiting a plastic deformation of up to 245% and less resistance (Young's modulus of 12.1 MPa) was obtained. With oxalic acid : proline, the material exhibited elastic deformation of up to 24% and a Young's modulus of only 9.9 MPa. A particular interest was also given to the valorization of the residual solid obtained from the extraction into high-value-added artificial humic substances.Universidade de VigoDeutscher Akademischer AustauschdienstAlexander von Humboldt-StiftungMax-Planck-Gesellschaf
Unraveling the profile of domestic cultural travelers in Spain: An analysis based on bootstrap p values
No full textThis study aims to determine whether domestic cultural and non-cultural travelers show significantly different socioeconomic and trip-related characteristics. We use microdata from the Resident Travel Survey 2019, conducted by the Spanish Statistical Office. The hypothesis testing of equal travelers’ characteristics is based on the calculation of bootstrap p values. Our findings reveal that domestic cultural travelers have a particular profile that is markedly different from other kinds of travelers: They have a higher level of education, but do not show significantly higher levels of income compared to non-cultural travelers. This finding has an important implication because it partly breaks with the deep-seated belief that cultural travelers are “up-scale” individuals. Additionally, cultural travelers spend significantly more money and travel significantly longer distances
Airborne Alternaria spores: 70 Annual records in Northwestern Spain
Get PDFThis study presents data on the concentration of Alternaria spores in the atmosphere of the northwestern Iberian Peninsula. A non-viable volumetric method was used to collect the samples, resulting in a database of 70 annual. When the annual averages for each locality are calculated, Ourense stands out with 2152 spores/m3, followed by Vigo and Lugo, while Santiago de Compostela recorded the lowest concentrations. Focusing on the total data for each locality, the main sporulation period started in May and ended in October in all localities, centered on a single phase, with an earlier onset and longer duration in Ourense and Vigo. The number of days with concentrations in excess of 100 spores/m3 was very low in Santiago de Compostela, Ourense, and Vigo and null in Lugo. Temperature was the meteorological parameter for which the highest statistical correlation was obtained in all locations, being favorable to the concentration of spores in the air. Temperature ranges favorable to the presence of airborne spores in the study area ranged from 25.5 to 31.2 °C. Based on the analysis of the data collected, it is concluded that Alternaria spore concentrations are low throughout most of the year.Universidade de Vigo | Ref. PREUVIGO-23Xunta de Galicia | Ref. ED431C 2023/19Xunta de Galicia | Ref. ED431C 2017/6
Comprehension of metaphorical utterances at an early age: A study with Spanish-speaking children of 3 and 4 years
Get PDFLa metáfora es un fenómeno de altísima frecuencia en la comunicación humana, aunque su comprensión requiere de unos procesos interpretativos complejos. Hasta hace poco, la mayoría de los trabajos apuntaban a un desarrollo tardío, sobre los 7-10 años, de la comprensión de los enunciados no literales (Winner et al. 1976; Johnson 1982; Dryll 2009), aunque estudios más recientes han reflejado la posibilidad de un desarrollo más temprano, a los 3 o 4 años (Siqueira y Gibbs 2007; Pouscoulous y Tomasello 2019). Así, los principales objetivos del trabajo son (i) estudiar la comprensión temprana de enunciados no literales del ámbito metafórico desde una perspectiva pragmática en un grupo hispanohablante atendiendo a las variables edad y sexo, y (ii) analizar la relación entre comprensión metafórica y conocimiento semántico específico. Para ello, contamos con una muestra de 115 niños de 3 y 4 años hablantes nativos de español a los que pasamos, en primer lugar, una prueba de comprensión de metáforas perceptivas basada en estímulos visuales —selección de imágenes— para no añadir complejidad metodológica a la tarea. En segundo lugar, se realizó una prueba de comprobación semántica que nos permitiese evaluar el conocimiento de las palabras necesarias para realizar correctamente la interpretación pragmática de la primera prueba. Los datos recogidos se analizaron con el programa estadístico SPSS. Los resultados de la investigación aportan evidencia científica a favor de un desarrollo más temprano de las habilidades pragmáticas pues los niños de las edades estudiadas demostraron ser capaces de interpretar correctamente los enunciados metafóricos seleccionados para el estudio, siendo la edad además una variable significativa y predictora constante. La otra variable estudiada no demostró ser estadísticamente significativa en la interpretación de los resultados. En cuanto al segundo objetivo, se establece una correlación positiva y significativa entre nivel de comprensión metafórica y conocimiento semántico específico. Este trabajo ha permitido aportar evidencia científica a un campo de estudio incipiente en el que solo la investigación futura podrá resolver las preguntas que todavía no tienen respuesta.The metaphor is a phenomenon of very high frequency in human communication, although its comprehension requires complex interpretative processes. Until recent years, most of the work showed a late development of the comprehension of non-literal utterances, at about 7-10-year-old (Winner et al. 1976; Johnson 1982; Dryll 2009), while recent studies have noted the possibility of earlier development, at 3 or 4 years old (Siqueira & Gibbs 2007; Pouscoulous & Tomasello 2019). Thus, the main aims of this study are (i) to examine the early comprehension of non-literal utterances of the metaphoric field from a pragmatic perspective in a Spanish-speaking group considering age and gender variables, and (ii) to analyse the relationship between metaphoric comprehension and specific semantic knowledge. For that purpose, we took a sample of 115 children aged 3 and 4, all Spanish
native speakers, and a visual comprehension test —image selection— of perceptive metaphors was performed at a first moment, trying with this type of test to avoid including methodological complexity to the task. Secondly, a semantic verification test was performed to evaluate the knowledge of the words which are necessary for a correct pragmatic interpretation of the first test. Collected data was
analysed with SPSS Statistical programme. The results of the research provide scientific evidence for an earlier development of pragmatic abilities as children of the analysed ages proved to be able to correctly interpret the metaphoric utterances of this study, being age a significative and constant predictor variable. The other analysed variable did not prove to be statistically significative when interpreting the results. As for the second aim, a positive and significative correlation is established between metaphoric comprehension level and specific semantic knowledge. This work has provided
scientific evidence to an emerging field of study in which only future research will solve those questions still with an answer
Fluorinated biphenyl phosphine ligands for accelerated [Au(I)]-Catalysis
No full textFluorinated JohnPhos-type ligands are proposed as accelerating tools in homogeneous gold(I) catalysis, with PedroPhosAuCl (Cat1) as the most efficient one. The ligands as well as the corresponding gold complexes were synthesized in high yields and fully characterized also via single-crystal X-ray diffraction. A secondary interaction between the distal phenyl ring of the phosphane ligand and the metal center is identified as key for the fine-tuning of the overall catalytic performance of the complexes. In particular, kinetic as well as computational analysis revealed that by accommodating F atoms on the biphenyl pendant of the ligand, more reactive organo-gold intermediates are realized toward subsequent nucleophilic condensations. The gold-catalyzed indole-hydroarylation of 1,6-enynes and the intramolecular hydroindolynation of alkynes have been adopted as benchmark reactions to exemplify these accelerating effects.Xunta de Galicia | Ref. ED481B-2023-044Agencia Estatal de Investigación | Ref. PID2020-115789GB-C2