3,420 research outputs found

    A deep-learning approach to mining conditions

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    A condition is a constraint that determines when a consequent holds. Mining them in text is paramount to understand many sentences properly. In the literature, there are a few pattern-based proposals that fall short regarding recall because it is not easy to characterise unusual ways to express conditions with hand-crafted patterns; there is one machine-learning proposal that is bound to the Japanese language, requires specific-purpose dictionaries, taxonomies, and heuristics, works on opinion sentences only, and was evaluated very shallowly. In this article, we present a deep-learning proposal to mine conditions that does not have any of the previous drawbacks; furthermore, we have performed a comprehensive experimental study on a large multi-lingual dataset on many common topics; our conclusion is that our proposals are similar to the state of the art in terms of precision, but improve recall enough to beat them in terms of F1 score.Ministerio de Economía y Competitividad TIN2013-40848-RMinisterio de Economía y Competitividad TIN2016-75394-

    Deformation of canonical morphisms and the moduli of surfaces of general type

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    In this article we study the deformation of finite maps and show how to use this deformation theory to construct varieties with given invariants in a projective space. Among other things, we prove a criterion that determines when a finite map can be deformed to a one--to--one map. We use this criterion to construct new simple canonical surfaces with different c12c_1^2 and χ\chi. Our general results enable us to describe some new components of the moduli of surfaces of general type. We also find infinitely many moduli spaces M(x,0,y)\mathcal M_{(x',0,y)} having one component whose general point corresponds to a canonically embedded surface and another component whose general point corresponds to a surface whose canonical map is a degree 2 morphism.Comment: 32 pages. Final version with some simplifications and clarifications in the exposition. To appear in Invent. Math. (the final publication is available at springerlink.com

    The Golden Period For Growth In Chile: Explanations And Forecasts

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    Economic growth in Chile since the mid 1980s has been remarkable for its high level and persistence. This paper explores the factors behind the high growth rates of the past 15 years and analyzes the extent to which they can be sustained in the future. The first part of the paper presents some stylized facts about growth in Chile. Taken together, they suggest that the jump in growth was driven by policies and macroeconomic conditions that affected the economy’s overall productivity. The second part of the paper considers the large body of recent empirical growth literature to examine the extent to which a cross-country approach can explain Chile’s growth performance. It formulates a basic regression model that contains the most popular variables in the growth literature and estimates it using techniques suited for dynamic models of panel data. The basic model allows us to explain about 45% of the change in the growth rate between 1970-1985 and 1986-1998, which was 4.74 percentage points. When we expand the basic model to include the quality of the political system and governance, the comprehensiveness and complementarity of policy reforms, and the availability of public services and infrastructure, we can explain 73% of the growth improvement. The last part of the paper starts the assessment of possible new growth sources for Chile by, first, projecting the country’s growth rate for the next 10 years under various assumptions and, second, proposing some areas with potentially large returns.

    New Perspectives on Audience Activity: ‘Prosumption’ and Media Activism as Audience Practices

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    Until relatively recently, the subject of social relationships, constituted in and through audience practices, has been a minor part of audience research studies. This chapter explores how social relationships and forms of audience agency change and / or evolve, through the usage of both traditional and ‘new’ media. In a media environment where traditional and new media worlds collide, the potential of audience practices to rework, not only media-audience relationships, but also wider social relationships, is now an important research theme. Two key examples of mediated relationships between social actors in conditions brought about through transformations in media culture are considered. We look at the evolution of audience ‘prosumption’ or ‘produsage’ (Bruns 2007), as well as at audience ‘activism’ (de Jong, Shaw and Stammers 2005). These examples are identified as illustrating new dynamics of social interaction, which may have the potential to contribute to larger, integrative social networks that transcend the existing boundaries of the traditional concept of audience. Against the background of traditional approaches to social relationships in the context of audience studies, we examine in both case studies the respective roles of the technologies, the social actors and the emergent social relationships concerned

    Substring filtering for low-cost linked data interfaces

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    Recently, Triple Pattern Fragments (TPFS) were introduced as a low-cost server-side interface when high numbers of clients need to evaluate SPARQL queries. Scalability is achieved by moving part of the query execution to the client, at the cost of elevated query times. Since the TPFS interface purposely does not support complex constructs such as SPARQL filters, queries that use them need to be executed mostly on the client, resulting in long execution times. We therefore investigated the impact of adding a literal substring matching feature to the TPFS interface, with the goal of improving query performance while maintaining low server cost. In this paper, we discuss the client/server setup and compare the performance of SPARQL queries on multiple implementations, including Elastic Search and case-insensitive FM-index. Our evaluations indicate that these improvements allow for faster query execution without significantly increasing the load on the server. Offering the substring feature on TPF servers allows users to obtain faster responses for filter-based SPARQL queries. Furthermore, substring matching can be used to support other filters such as complete regular expressions or range queries

    Survey for Emission-Line Galaxies: Universidad Complutense de Madrid List 3

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    A new low-dispersion objective-prism search for low-redshift (z<0.045) emission-line galaxies (ELG) has been carried out by the Universidad Complutense de Madrid with the Schmidt Telescope at the Calar-Alto Observatory. This is a continuation of the UCM Survey, which was performed by visual selection of candidates in photographic plates via the presence of the Halpha+[NII]6584 blend in emission. In this new list we have applied an automatic procedure, fully developed by us, for selecting and analyzing the ELG candidates on the digitized images obtained with the MAMA machine. The analyzed region of the sky covers 189 square degrees in nine fields near R.A.=14h & 17h, Dec=25 deg. The final sample contains 113 candidates. Special effort has been made to obtain a large amount of information directly from our uncalibrated plates by using several external calibrations. The parameters obtained for the ELG candidates allow for the study of the statistical properties for the sample.Comment: 13 pages, 18 PostScript figures, 6 JPEG figures, Table 2 corrected. Accepted for publication in Astrophysical Journal Supplements, also available at http://www.ucm.es/info/Astrof/opera/LIST3_ApJS99

    Automatic selection of new Hα emission-line galaxies using MAMA

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    A full set of algorithms for the automatic analysis of low-resolution objective-prism spectra has been developed with the aim of finding new emission-line galaxies (ELGs) candidates from the Universidad Complutense de Madrid (UCM) survey prism plates. An objective-prism plate and a direct plate, used for pairing objects and to perform star-galaxy separation, have been scanned with the MAMA machine. The plates were taken in the red region of the spectrum, using the Hα+[NII] blend in emission as selection criterion. The procedure, applied to digitized spectra, is able to automatically select ELGs candidates. Density to intensity transformation has not been used in our method; the detection of the emission is performed applying three independent criteria over the one-dimensional spectra in raw data. The automatically selected sample is compared with that obtained after a careful visual scan. Spectroscopic observations at moderate spectral resolution are presented for the whole sample of candidates in order to study the drawbacks and the biases of both methods

    Perceptive training of youth volleyball blockers

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    Este estudio analiza la eficacia de un programa de entrenamiento perceptivo basado en la orientación de la atención para la mejora de la toma de decisiones y el rendimiento en la acción de bloqueo de voleibol. 16 jugadoras juveniles fueron distribuidas en tres grupos: vídeo (n=6), que recibió ocho sesiones de entrenamiento en vídeo; mixto (n=5), que recibió 4 sesiones en vídeo y 4 sesiones de práctica en campo; y control (n=5), que completó las pruebas de evaluación. Los resultados muestran cómo el programa de entrenamiento mejoró la toma de decisiones de las jugadoras, ya que redujeron su tiempo de reacción (F(1,13)=9,237, p=0,009, ηp 2=0,415) manteniendo el mismo porcentaje de aciertos. Sin embargo, es necesaria la práctica en campo para lograr transferir dichos aprendizajes al juego real, ya que sólo el grupo mixto mejora el porcentaje de aciertos en el test de rendimiento en campo (F(2,13)=8,608, p=0,004, ηp2=0,570; t(4) =-6,216, p=0,003)This study examines the effectiveness of a training program based on perceptual orientation of attention for improving decision-making and performance in the blocking action of volleyball. 16 youth players were divided into three groups: video (n=6), which received eight perceptual training sessions by video; mixed (n=5), which received only half of the sessions by video, combined with practical training in the field; and control (n=5), which just completed pre-test and post-test tests. Results show how orientation of attention to relevant areas of information improved decision-making of the youth volleyball players because they reduced their reaction time (F(1,13)=9,237, p=0,009, ηp2=0,415) maintaining the same percentage of success. However, the practice on the field is necessary to achieve transfer those learning to the real game, because only mixed group improves the percentage of success in the field performance test (F(2,13)=8,608, p=0,004, ηp2=0,570; t(4)=-6,216, p=0,003

    Matrix approach to noncommutative stably free modules and Hermite rings

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    In this paper we present a matrix-constructive proof of an Stafford’s Theorem about stably free modules over noncommutative rings. Matrix characterizations of noncommutative Hermite and projective-free rings are exhibit. Quotients, products and localizations of Hermite and some other classes of rings close related to Hermite rings are also considered

    The interception of a corner kick from the contraints-led perspective

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    El comportamiento motor surge de la continua interacción entre tres limitadores (organismo, entorno y tarea), que nunca actúan de forma aislada. Este artículo estudia su efecto en el rendimiento, comportamiento motor y comportamiento visual de porteros de fútbol durante el lanzamiento de córner. 31 participantes, divididos en tres grupos en función del nivel de juego, intentaron atrapar el balón procedente del lanzamiento de córner en dos situaciones (estática y dinámica), mientras que se registraron sus movimientos oculares. Entre los resultados se observa que los expertos tienen un rendimiento más estable, mientras que los otros grupos rinden peor en la situación más difícil; que los expertos realizan un inicio más tardío de la carrera hacia el balón y un patrón motor más rápido para atraparlo; y que la información contenida en los jugadores implicados no es relevante, ya que los porteros dedican valores cercanos al 0% del tiempo total a su fijaciónMotor behavior arises from the continuous interaction between three constraints (organism, environment and task), which never act in isolation. This paper studies the effect of the constraints on the performance, motor behavior and visual search behavior of soccer goalkeepers during the corner kick. 31 participants, divided into three groups depending on the level of play, tried to catch the ball out of a corner kick in two situations (static and dynamic), while their eye movements were recorded. Among the results it is observed that the experts have a more stable performance, while the other groups perform worse in the most difficult situation; that the experts make a later start of their run up towards the ball and a faster motor pattern to catch it; and that the that the information of the players involved is not relevant, goalkeepers dedicate values close to 0% of their visual total time to themLa presente investigación se llevó a cabo mientras el primer autor y la segunda autora disfrutaban de una beca FPU (Formación del Profesorado Universitario) otorgada por el Ministerio de Educación, Cultura y Deporte del Gobierno de España
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