9,003 research outputs found
Extending, trimming and fusing WordNet for technical documents
This paper describes a tool for the automatic
extension and trimming of a multilingual
WordNet database for cross-lingual retrieval
and multilingual ontology building in
intranets and domain-specific document
collections. Hierarchies, built from
automatically extracted terms and combined
with the WordNet relations, are trimmed
with a disambiguation method based on the
document salience of the words in the
glosses. The disambiguation is tested in a
cross-lingual retrieval task, showing
considerable improvement (7%-11%). The
condensed hierarchies can be used as
browse-interfaces to the documents
complementary to retrieval
Measurement of Transverse Spin Effects at COMPASS
By measuring transverse single spin asymmetries one has access to the
transversity distribution function and the transverse momentum
dependent Sivers function . New measurements from
identified hadrons and hadron pairs, produced in deep inelastic scattering of a
transversely polarized target are presented. The data were taken in
2003 and 2004 by the COMPASS collaboration using the muon beam of the CERN SPS
at 160 GeV/c, resulting in small asymmetries.Comment: 4 pages, 7 figures, in proceedings for 'Rencontres de Moriond 2007,
QCD and Hadronic interactions
Support Vector Machines in High Energy Physics
This lecture will introduce the Support Vector algorithms for classification
and regression. They are an application of the so called kernel trick, which
allows the extension of a certain class of linear algorithms to the non linear
case. The kernel trick will be introduced and in the context of structural risk
minimization, large margin algorithms for classification and regression will be
presented. Current applications in high energy physics will be discussed.Comment: 11 pages, 12 figures. Part of the proceedings of the Track
'Computational Intelligence for HEP Data Analysis' at iCSC 200
Identity and Granularity of Events in Text
In this paper we describe a method to detect event descrip- tions in
different news articles and to model the semantics of events and their
components using RDF representations. We compare these descriptions to solve a
cross-document event coreference task. Our com- ponent approach to event
semantics defines identity and granularity of events at different levels. It
performs close to state-of-the-art approaches on the cross-document event
coreference task, while outperforming other works when assuming similar quality
of event detection. We demonstrate how granularity and identity are
interconnected and we discuss how se- mantic anomaly could be used to define
differences between coreference, subevent and topical relations.Comment: Invited keynote speech by Piek Vossen at Cicling 201
Strategic and tactical decisions, sunk costs and firm size effects in R&D
This paper investigates asymmetric effects of monetary policy over the business cycle. A two-state Markov Switching Model is employed to model both recessions and expansions. For the United States and Germany, strong evidence is found that monetary policy is more effective in a recession than during a boom. Also some evidence is found for asymmetry in the United Kingdom and Belgium. In the Netherlands, monetary policy is not very effective in either regime.
Basics of Feature Selection and Statistical Learning for High Energy Physics
This document introduces basics in data preparation, feature selection and
learning basics for high energy physics tasks. The emphasis is on feature
selection by principal component analysis, information gain and significance
measures for features. As examples for basic statistical learning algorithms,
the maximum a posteriori and maximum likelihood classifiers are shown.
Furthermore, a simple rule based classification as a means for automated cut
finding is introduced. Finally two toolboxes for the application of statistical
learning techniques are introduced.Comment: 12 pages, 8 figures. Part of the proceedings of the Track
'Computational Intelligence for HEP Data Analysis' at iCSC 200
Subsonic near-surface P-velocity and low S-velocity observations using propagator inversion
Detailed knowledge of near-surface P- and S-wave velocities is important for processing and interpreting multicomponent land seismic data because (1) the entire wavefield passes through and is influenced by the near-surface soil conditions, (2) both source repeatability and receiver coupling also depend on these conditions, and (3) near-surface P- and S-wave velocities are required for wavefield decomposition and demultiple methods. However, it is often difficult to measure these velocities with conventional techniques because sensitivity to shallow-wave velocities is low and because of the presence of sharp velocity contrasts or gradients close to the earth's free surface. We demonstrate that these near-surface P- and S-wave velocities can be obtained using a propagator inversion. This approach requires data recorded by at least one multicomponent geophone at the surface and an additional multicomponent geophone at depth. The propagator between them then contains all information on the medium parameters governing wave propagation between the geophones at the surface and at depth. Hence, inverting the propagator gives local estimates for these parameters. This technique has been applied to data acquired in Zeist, the Netherlands. The near-surface sediments at this site are unconsolidated sands with a thin vegetation soil on top, and the sediments considered are located above the groundwater table. A buried geophone was positioned 1.05 m beneath receivers on the surface. Propagator inversion yielded low near-surface velocities, namely, 270 ± 15 m/s for the compressional-wave velocity, which is well below the sound velocity in air, and 150 ± 9 m/s for the shear velocity. Existing methods designed for imaging deeper structures cannot resolve these shallow material properties. Furthermore, velocities usually increase rapidly with depth close to the earth's surface because of increasing confining pressure. We suspect that for this reason, subsonic near-surface P-wave velocities are not commonly observed
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