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Modeling the fake news challenge as a cross-level stance detection task
The 2017 Fake News Challenge Stage 1, a shared task for stance detection of news articles and claims pairs, has received a lot of attention in recent years [3]. The provided dataset is highly unbalanced, with a skewed distribution towards unrelated samples - that is, randomly generated pairs of news and claims belonging to different topics. This imbalance favored systems which performed particularly well in classifying those noisy samples, something which does not require a deep semantic understanding.
In this paper, we propose a simple architecture based on conditional encoding, carefully designed to model the internal structure of a news article and its relations with a claim. We demonstrate that our model, which only leverages information from word embeddings, can outperform a system based on a large number of hand-engineered features, which replicates one of the winning systems at the Fake News Challenge [6], in the stance detection of the related samples
A parallel multigrid solver for multi-patch Isogeometric Analysis
Isogeometric Analysis (IgA) is a framework for setting up spline-based
discretizations of partial differential equations, which has been introduced
around a decade ago and has gained much attention since then. If large spline
degrees are considered, one obtains the approximation power of a high-order
method, but the number of degrees of freedom behaves like for a low-order
method. One important ingredient to use a discretization with large spline
degree, is a robust and preferably parallelizable solver. While numerical
evidence shows that multigrid solvers with standard smoothers (like Gauss
Seidel) does not perform well if the spline degree is increased, the multigrid
solvers proposed by the authors and their co-workers proved to behave optimal
both in the grid size and the spline degree. In the present paper, the authors
want to show that those solvers are parallelizable and that they scale well in
a parallel environment.Comment: The first author would like to thank the Austrian Science Fund (FWF)
for the financial support through the DK W1214-04, while the second author
was supported by the FWF grant NFN S117-0
The first magnetic maps of a pre-main sequence binary star system - HD 155555
We present the first maps of the surface magnetic fields of a pre-main
sequence binary system. Spectropolarimetric observations of the young, 18 Myr,
HD 155555 (V824 Ara, G5IV + K0IV) system were obtained at the Anglo-Australian
Telescope in 2004 and 2007. Both datasets are analysed using a new binary
Zeeman Doppler imaging (ZDI) code. This allows us to simultaneously model the
contribution of each component to the observed circularly polarised spectra.
Stellar brightness maps are also produced for HD 155555 and compared to
previous Doppler images. Our radial magnetic maps reveal a complex surface
magnetic topology with mixed polarities at all latitudes. We find rings of
azimuthal field on both stars, most of which are found to be non-axisymmetric
with the stellar rotational axis. We also examine the field strength and the
relative fraction of magnetic energy stored in the radial and azimuthal field
components at both epochs. A marked weakening of the field strength of the
secondary star is observed between the 2004 and 2007 epochs. This is
accompanied by an apparent shift in the location of magnetic energy from the
azimuthal to radial field. We suggest that this could be indicative of a
magnetic activity cycle. We use the radial magnetic maps to extrapolate the
coronal field (by assuming a potential field) for each star individually - at
present ignoring any possible interaction. The secondary star is found to
exhibit an extreme tilt (~75 deg) of its large scale magnetic field to that of
its rotation axis for both epochs. The field complexity that is apparent in the
surface maps persists out to a significant fraction of the binary separation.
Any interaction between the fields of the two stars is therefore likely to be
complex also. Modelling this would require a full binary field extrapolation.Comment: 17 pages, 12 figures, accepted for publication in MNRA
Will-they-won't-they: A very large dataset for stance detection on twitter
We present a new challenging stance detection dataset, called Will-They-Wonât-They (WT--WT), which contains 51,284 tweets in English, making it by far the largest available dataset of the type. All the annotations are carried out by experts; therefore, the dataset constitutes a high-quality and reliable benchmark for future research in stance detection. Our experiments with a wide range of recent state-of-the-art stance detection systems show that the dataset poses a strong challenge to existing models in this domain.Keynes Fund, Cambridg
On the accuracy of retrieved wind information from Doppler lidar observations
A single pulsed Doppler lidar was successfully deployed to measure air flow and turbulence over the Malvern hills, Worcester, UK. The DERA Malvern lidar used was a CO2 ”m pulsed Doppler lidar. The lidar pulse repetition rate was 120 Hz and had a pulse duration of 0.6 ”s The system was set up to have 41 range gates with range resolution of 112 m. This gave a theoretical maximum range of approximately 4.6 km. The lidar site was 2 km east of the Malvern hill ridge which runs in a north-south direction and is approximately 6 km long. The maximum height of the ridge is 430 m. Two elevation scans (Range-Height Indicators) were carried out parallel and perpendicular to the mean surface flow. Since the surface wind was primarily westerly the scans were carried out perpendicular and parallel to the ridge of the Malvern hills.
The data were analysed and horizontal winds, vertical winds and turbulent fluxes were calculated for profiles throughout the boundary layer. As an aid to evaluating the errors associated with the derivation of velocity and turbulence profiles, data from a simple idealized profile was also analysed using the same method. The error analysis shows that wind velocity profiles can be derived to an accuracy of 0.24 m s-1 in the horizontal and 0.3 m s-1 in the vertical up to a height of 2500 m. The potential for lidars to make turbulence measurements, over a wide area, through the whole depth of the planetary boundary layer and over durations from seconds to hours is discussed
The first WASP public data release
The WASP (wide angle search for planets) project is an exoplanet transit survey that has been automatically taking wide field images since 2004. Two instruments, one in La Palma and the other in South Africa, continually monitor the night sky, building up light curves of millions of unique objects. These light curves are used to search for the characteristics of exoplanetary transits. This first public data release (DR1) of the WASP archive makes available all the light curve data and images from 2004 up to 2008 in both the Northern and Southern hemispheres. A web interface () to the data allows easy access over the Internet. The data set contains 3â631â972 raw images and 17â970â937 light curves. In total the light curves have 119â930â299â362 data points available between them
Analysis of the potential of cancer cell lines to release tissue factor-containing microvesicles: correlation with tissue factor and PAR2 expression
BackgroundDespite the association of cancer-derived circulating tissue factor (TF)-containing microvesicles and hypercoagulable state, correlations with the incidence of thrombosis remain unclear.MethodsIn this study the upregulation of TF release upon activation of various cancer cell lines, and the correlation with TF and PAR2 expression and/or activity was examined. Microvesicle release was induced by PAR2 activation in seventeen cell lines and released microvesicle density, microvesicle-associated TF activity, and phoshpatidylserine-mediated activity were measured. The time-course for TF release was monitored over 90 min in each cell line. In addition, TF mRNA expression, cellular TF protein and cell-surface TF activities were quantified. Moreover, the relative expression of PAR2 mRNA and cellular protein were analysed. Any correlations between the above parameters were examined by determining the Pearsonâs correlation coefficients.ResultsTF release as microvesicles peaked between 30â60 min post-activation in the majority of cell lines tested. The magnitude of the maximal TF release positively correlated with TF mRNA (câ=â0.717; p
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