3,463 research outputs found
A deep-learning approach to mining conditions
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
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 and . 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 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
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
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
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
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
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
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
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
On the synthesis of metadata tags for HTML files
RDFa, JSON-LD, Microdata, and Microformats allow to endow the data in
HTML files with metadata tags that help software agents understand them.
Unluckily, there are many HTML files that do not have any metadata tags,
which has motivated many authors to work on proposals to synthesize them.
But they have some problems: the authors either provide an overall picture of
their designs without too many details on the techniques behind the scenes or
focus on the techniques but do not describe the design of the software systems
that support them; many of them cannot deal with data that are encoded using
semistructured formats like forms, listings, or tables; and the few proposals that
can work on tables can deal with horizontal listings only. In this article, we
describe the design of a system that overcomes the previous limitations using a
novel embedding approach that has proven to outperform four state-of-the-art
techniques on a repository with randomly selected HTML files from 40 differ ent sites. According to our experimental analysis, our proposal can achieve an
F1 score that outperforms the others by 10.14%; this difference was confirmed
to be statistically significant at the standard confidence level.Junta de Andalucía P18-RT-1060Ministerio de Economía y Competitividad TIN2013-40848-RMinisterio de Economía y Competitividad TIN2016-75394-
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