Entities as topic labels: Improving topic interpretability and evaluability combining Entity Linking and Labeled LDA

In order to create a corpus exploration method providing topics that are easier to interpret than standard LDA topic models, here we propose combining two techniques called Entity linking and Labeled LDA. Our method identifies in an ontology a series of descriptive labels for each document in a corpus. Then it generates a specific topic for each label. Having a direct relation between topics and labels makes interpretation easier; using an ontology as background knowledge limits label ambiguity. As our topics are described with a limited number of clear-cut labels, they promote interpretability, and this may help quantitative evaluation. We illustrate the potential of the approach by applying it in order to define the most relevant topics addressed by each party in the European Parliament's fifth mandate (1999-2004).Comment: in Proceedings of Digital Humanities 2016, Krako

Understanding Fomalhaut as a Cooper pair

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Fomalhaut is a nearby stellar system and has been found to be a triple based on astrometric observations. With new radial velocity and astrometric data, we study the association between Fomalhaut A, B, and C in a Bayesian framework, finding that the system is gravitationally bound or at least associated. Based on simulations of the system, we find that Fomalhaut C can be easily destabilized through combined perturbations from the Galactic tide and stellar encounters. Considering that observing the disruption of a triple is probably rare in the solar neighbourhood, we conclude that Fomalhaut C is a so-called 'gravitational pair' of Fomalhaut A and B. Like the Cooper pair mechanism in superconductors, this phenomenon only appears once the orbital energy of a component becomes comparable with the energy fluctuations caused by the environment. Based on our simulations, we find (1) an upper limit of 8 kms -1 velocity difference is appropriate when selecting binary candidates, and (2) an empirical formula for the escape radius, which is more appropriate than tidal radius when measuring the stability of wide binaries.Peer reviewe

Activity and telluric contamination in HARPS observations of Alpha Centauri B

© 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society.The Alpha Centauri system is the primary target for planet search as it is the closest star system composed of a solar twin α CenA, a K-dwarf α Cen B, and an M-dwarf Proxima Centauri, which has a confirmed planet in the temperate zone. α CenA and B weremonitored intensively with the HARPS spectrograph for over 10 yr, providing high-precision radial velocity (RV) measurements. In this work, we study the available data to better understand the stellar activity and other contaminating signals.We highlight the importance of telluric contamination and its impact on the RV measurements. Our suggested procedures lead to discarding about 5 per cent of HARPS data, providing a data set with an rms improved by a factor of 2. We compile and quantify the behaviour of 345 spectral lines with a wide range of line shapes and sensitivity to activity.Peer reviewedFinal Published versio

Ordenación del territorio

La ponencia aporta una explicación al concepto de ordenación del territorio, su metodología y sistemas de aplicación y los enfoques y doctrinas más generalizados en este campo. Pone las pautas para cualquier planificación territorial y concede importancia a la información relativa al medio físico, a la relación uso-territorio y a las infraestructuras (naturales y artificiales

Towards an understanding of job matching using web data

The thesis explores the feasibility of using web data in labour research in general and of applying these data sources to the study of job matching in particular. Utilizing large-scale data sources, including web surveys and online job vacancies, the thesis aims to identify where the state of the art is and lay methodological, conceptual and analytical foundations for further exploration and research in the area. Formally, the thesis consists of five essays, which either have been or are on the way to be published in scientific journals

Digital workers by design? An example from the on-demand economy. CEPS Working Document No. 414/October 2015 Monday, 19 October 2015

Recent organisational and technological changes à la Uber have generated a new labour market fringe: a digital class of workers and contractors. In this paper we study the case of CoContest, a crowdsourcing platform for interior design. Our objective is to investigate how profitable this type of work can be, also from a cross-country perspective, and why professionals choose to supply work on such a platform. Given the low returns, one might expect to see a pattern of northern employer/southern contractor. Yet analysis reveals a more nuanced pattern, in which designers supply their work even if they live in Italy, which is a high-income country. For these designers work on CoContest can make sense if they are new to the labour market and face high entry barriers, although crowdsourcing does not offer them profitable employment full time. The case of Serbia, the second-largest supplier of designers, is different, however. As a result of differences in purchasing power, if the market grows experienced Serbian designers can expect to make a living from crowdsourced contracts

Are student workers a threat or a solution? CEPS Commentary, 14 July 2015

The massification of tertiary education means that a significant percentage of young people participate in tertiary education while also working. They can be seen as a threat – as cheap and highly qualified competition for low-skilled workers in casual jobs who are setting aside their studies for the time being in favour of immediate income. Or they might present an opportunity – a natural way for a large percentage of young people to gain experience and contact with the labour market without the need for massive government programmes. The authors argue in this CEPS commentary that student work is more of an opportunity than a threat