919 research outputs found
Overview of the CLEF 2023 SimpleText Lab:Automatic Simplification of Scientific Texts
There is universal consensus on the importance of objective scientific information, yet the general public tends to avoid scientific literature due to access restrictions, its complex language or their lack of prior background knowledge. Academic text simplification promises to remove some of these barriers, by improving the accessibility of scientific text and promoting science literacy. This paper presents an overview of the CLEF 2023 SimpleText track addressing the challenges of text simplification approaches in the context of promoting scientific information access, by providing appropriate data and benchmarks, and creating a community of IR and NLP researchers working together to resolve one of the greatest challenges of today. The track provides a corpus of scientific literature abstracts and popular science requests. It features three tasks. First, content selection (what is in, or out?) challenges systems to select passages to include in a simplified summary in response to a query. Second, complexity spotting (what is unclear?) given a passage and a query, aims to rank terms/concepts that are required to be explained for understanding this passage (definitions, context, applications). Third, text simplification (rewrite this!) given a query, asks to simplify passages from scientific abstracts while preserving the main content.</p
The natural science of cosmology
The network of cosmological tests is tight enough now to show that the
relativistic Big Bang cosmology is a good approximation to what happened as the
universe expanded and cooled through light element production and evolved to
the present. I explain why I reach this conclusion, comment on the varieties of
philosophies informing searches for a still better cosmology, and offer an
example for further study, the curious tendency of some classes of galaxies to
behave as island universes.Comment: Keynote lecture at the seventh International Conference on
Gravitation and Cosmology, Goa India, December 201
Overview of SimpleText 2021 - CLEF Workshop on Text Simplification for Scientific Information Access
MASSIV: Mass Assembly Survey with SINFONI in VVDS. VI. Metallicity-related fundamental relations in star-forming galaxies at
The MASSIV (Mass Assembly Survey with SINFONI in VVDS) project aims at
finding constraints on the different processes involved in galaxy evolution.
This study proposes to improve the understanding of the galaxy mass assembly
through chemical evolution using the metallicity as a tracer of the star
formation and interaction history. Methods. We analyse the full sample of
MASSIV galaxies for which a metallicity estimate has been possible, that is 48
star-forming galaxies at , and compute the integrated values of
some fundamental parameters, such as the stellar mass, the metallicity and the
star formation rate (SFR). The sample of star-forming galaxies at similar
redshift from zCOSMOS (P\'erez-Montero et al. 2013) is also combined with the
MASSIV sample. We study the cosmic evolution of the mass-metallicty relation
(MZR) together with the effect of close environment and galaxy kinematics on
this relation. We then focus on the so-called fundamental metallicity relation
(FMR) proposed by Mannucci et al. (2010) and other relations between stellar
mass, SFR and metallicity as studied by Lara-L\'opez et al. (2010). We
investigate if these relations are really fundamental, i.e. if they do not
evolve with redshift. Results. The MASSIV galaxies follow the expected
mass-metallicity relation for their median redshift. We find however a
significant difference between isolated and interacting galaxies as found for
local galaxies: interacting galaxies tend to have a lower metallicity. The
study of the relation between stellar mass, SFR and metallicity gives such
large scattering for our sample, even combined with zCOSMOS, that it is
diffcult to confirm or deny the existence of a fundamental relation
The ALHAMBRA survey: An empirical estimation of the cosmic variance for merger fraction studies based on close pairs
Aims. Our goal is to estimate empirically the cosmic variance that affects merger fraction studies based on close pairs for the first time.
Methods. We compute the merger fraction from photometric redshift close pairs with 10 h-1 kpc ≤ rp ≤ 50 h-1 kpc and Δv ≤ 500 km s-1 and measure it in the 48 sub-fields of the ALHAMBRA survey. We study the distribution of the measured merger fractions that follow a log-normal function and estimate the cosmic variance σv as the intrinsic dispersion of the observed distribution. We develop a maximum likelihood estimator to measure a reliable σv and avoid the dispersion due to the observational errors (including the Poisson shot noise term).
Results. The cosmic variance σv of the merger fraction depends mainly on (i) the number density of the populations under study for both the principal (n1) and the companion (n2) galaxy in the close pair and (ii) the probed cosmic volume Vc. We do not find a significant dependence on either the search radius used to define close companions, the redshift, or the physical selection (luminosity or stellar mass) of the samples.
Conclusions. We have estimated the cosmic variance that affects the measurement of the merger fraction by close pairs from observations. We provide a parametrisation of the cosmic variance with n1, n2, and Vc, σv ∝ n1-0.54Vc-0.48 (n_2/n_1)-0.37 . Thanks to this prescription, future merger fraction studies based on close pairs could properly account for the cosmic variance on their results
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