5,958 research outputs found
Enriching Existing Test Collections with OXPath
Extending TREC-style test collections by incorporating external resources is
a time consuming and challenging task. Making use of freely available web data
requires technical skills to work with APIs or to create a web scraping program
specifically tailored to the task at hand. We present a light-weight
alternative that employs the web data extraction language OXPath to harvest
data to be added to an existing test collection from web resources. We
demonstrate this by creating an extended version of GIRT4 called GIRT4-XT with
additional metadata fields harvested via OXPath from the social sciences portal
Sowiport. This allows the re-use of this collection for other evaluation
purposes like bibliometrics-enhanced retrieval. The demonstrated method can be
applied to a variety of similar scenarios and is not limited to extending
existing collections but can also be used to create completely new ones with
little effort.Comment: Experimental IR Meets Multilinguality, Multimodality, and Interaction
- 8th International Conference of the CLEF Association, CLEF 2017, Dublin,
Ireland, September 11-14, 201
Cooperative dynamics in doped manganite films: phonon anomalies in the ferromagnetic state
We present optical measurements of phononic excitations in
LaCaMnO (LCMO) and LaSrMnO (LSMO)
thin films covering the full temperature range from the metallic ferromagnetic
to the insulating paramagnetic phase. All eight phonons expected for the
Rc symmetry in LSMO and 17 out of the expected 25 phonons for the Pnma
symmetry in LCMO have been determined. Close to the
ferromagnetic-to-paramagnetic transition both compounds reveal an anomalous
behavior but with different characteristics. Anomalies in the phononic spectra
are a manifestation of the coupling of lattice degrees of freedom (DOF) to
electronic DOF. Specifically, the low-frequency external group proves to be an
indicator for lattice modifications induced by electronic correlations. The
enhanced electron-phonon coupling in LCMO is responsible for Fano-like
interference effects of distinct phonon modes with electronic continuum
excitations: we observe asymmetric phonon line shapes, mode splitting and
spectral weight transfer between modes.Comment: 10 pages, 10 figure
The Menstrual Cycle and Performance Feedback Alter Gender Differences in Competitive Choices
Economic experiments have shown that in mixed gender groups women are more reluctant than men to choose tournaments when given the choice between piece rate and winner-take-all tournament style compensation. These gender difference experiments have all relied on a framework where subjects were not informed of their abilities relative to potential competitors. We replicate these findings with math and word tasks, and then show that feedback about relative performance moves high ability females towards more competitive compensation schemes, moves low ability men towards less competitive schemes such as piece rate and group pay, and removes the average gender difference in compensation choices. We also examine between and within-subjects differences in choices for females across the menstrual cycle. We find women's relative reluctance to choose tournaments comes mostly from women in the low hormone phase of their menstrual cycle. Women in the high hormone phase are substantially more willing to compete than women in the low phase, though still somewhat less willing to compete than men. There are no significant differences between the choices of any of these groups after they receive relative performance feedback.competition, tournaments, gender, hormones, menstruation, feedback
eingesetzt wird. A. nutzt dazu die Boolesche Logik (Algebra) mit den Operatoren AND, OR und NOT. Die logischen Operatoren ergeben folgende Mengen: A AND B
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Large and Small Polaron Excitations in La2/3(Sr/Ca)1/3MnO3 Films
We present detailed optical measurements of the mid-infrared (MIR)
excitations in thin films of La2/3Sr1/3MnO3 (LSMO) and La2/3Ca1/3MnO3 (LCMO)
across the magnetic transition. The shape of the excitation at about 0.2 eV in
both samples is analyzed in terms of polaron models. We propose to identify the
MIR resonance in LSMO as the excitation of large polarons and that in LCMO as a
small polaron excitation. A scaling behavior for the low-energy side of the
polaronic MIR resonance in LSMO is established
Spin-phonon coupling in antiferromagnetic chromium spinels
The temperature dependence of eigenfrequencies and intensities of the IR
active modes has been investigated for the antiferromagnetic chromium spinel
compounds CdCr2O4, ZnCr2O4, ZnCr2S4, ZnCr2Se4, and HgCr2S4 by IR spectroscopy
for temperatures from 5 K to 300 K. At the transition into the magnetically
ordered phases, and driven by spin-phonon coupling, most compounds reveal
significant splittings of the phonon modes. This is true for geometrically
frustrated CdCr2O4, and ZnCr2O4, for bond frustrated ZnCr2S4 and for ZnCr2Se4,
which also is bond frustrated, but dominated by ferromagnetic exchange. The
pattern of splitting is different for the different compounds and crucially
depends on the nature of frustration and of the resulting spin order. HgCr2S4,
which is almost ferromagnetic, exhibits no splitting of the eigenfrequencies,
but shows significant shifts due to ferromagnetic spin fluctuations.Comment: 15 pages, 6 figure
Amorphous thin film growth: theory compared with experiment
Experimental results on amorphous ZrAlCu thin film growth and the dynamics of
the surface morphology as predicted from a minimal nonlinear stochastic
deposition equation are analysed and compared. Key points of this study are (i)
an estimation procedure for coefficients entering into the growth equation and
(ii) a detailed analysis and interpretation of the time evolution of the
correlation length and the surface roughness. The results corroborate the
usefulness of the deposition equation as a tool for studying amorphous growth
processes.Comment: 7 pages including 5 figure
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