Graphene: A Context-Preserving Open Information Extraction System

We introduce Graphene, an Open IE system whose goal is to generate accurate, meaningful and complete propositions that may facilitate a variety of downstream semantic applications. For this purpose, we transform syntactically complex input sentences into clean, compact structures in the form of core facts and accompanying contexts, while identifying the rhetorical relations that hold between them in order to maintain their semantic relationship. In that way, we preserve the context of the relational tuples extracted from a source sentence, generating a novel lightweight semantic representation for Open IE that enhances the expressiveness of the extracted propositions.Comment: 27th International Conference on Computational Linguistics (COLING 2018

Graphene: Semantically-Linked Propositions in Open Information Extraction

We present an Open Information Extraction (IE) approach that uses a two-layered transformation stage consisting of a clausal disembedding layer and a phrasal disembedding layer, together with rhetorical relation identification. In that way, we convert sentences that present a complex linguistic structure into simplified, syntactically sound sentences, from which we can extract propositions that are represented in a two-layered hierarchy in the form of core relational tuples and accompanying contextual information which are semantically linked via rhetorical relations. In a comparative evaluation, we demonstrate that our reference implementation Graphene outperforms state-of-the-art Open IE systems in the construction of correct n-ary predicate-argument structures. Moreover, we show that existing Open IE approaches can benefit from the transformation process of our framework.Comment: 27th International Conference on Computational Linguistics (COLING 2018

Influence of Ar gas pressure on ion energy and charge state distributions in pulsed cathodic arc plasmas from Nb-Al cathodes studied with high time resolution

For cathodic arcs, the cathode material is one of the most important determinants of plasma properties. Consequently, the cathode material - plasma relationship is of special interest in related fundamental research as well as in applications like the synthesis of thin films and coatings. In the latter, the use of multi-element cathodes in inert as well as reactive gas atmospheres is common practice. To further improve the physical understanding of cathodic arcs in such settings, we analyze ions in pulsed cathodic arc plasmas from Nb, Al and two composite Nb-Al cathodes with high time-resolution using a mass-energy-analyzer. The experiments were conducted in Ar atmosphere at total pressures of 0.04, 0.20 and 0.40 Pa, and are compared to earlier results in high vacuum at 10-4. In addition to examining the influence of Ar on ion properties and their cathode material dependence, the results are used to discuss physical concepts in cathodic arcs, like the gas-dynamic expansion of the cathode spot plasma, or the influence of charge exchange collisions of ions with neutrals. While such inelastic collisions e.g. with Ar atoms cause a reduction of charge states to mainly Al+ and Nb2+ at the highest pressure, Ar atoms also seem to take part in near-cathode processes. Ar ions in different time and energy regimes up to 150 eV were observed and compared to Nb and Al ions, showing overlapping velocity distributions for Nb, Al and Ar+ ions, but also Ar2+ ions faster than other ion species. © 2018 IOP Publishing Ltd

A Survey on Open Information Extraction

We provide a detailed overview of the various approaches that were proposed to date to solve the task of Open Information Extraction. We present the major challenges that such systems face, show the evolution of the suggested approaches over time and depict the specific issues they address. In addition, we provide a critique of the commonly applied evaluation procedures for assessing the performance of Open IE systems and highlight some directions for future work.Comment: 27th International Conference on Computational Linguistics (COLING 2018

Gerhard Lang (21.10.1924–19.6.2016)

Gerhard Lang, one of the great German botanists and palaeoecologists of the 20th century, died on the 19th June 2016 in Biberach, southern Germany. He will be greatly missed by his friends and colleagues, not only for his vast expertise in botany, ecology, biogeography, and vegetation history, but also for his integrity, kindness, and humour. For many of his students and post-doctoral fellows he was not only an excellent teacher and mentor, but also an important role model

Syn-kinematic magma ascent and batholith inflation (Sierra de San Luis/Argentina)

The measurement of the anisotropy of the magnetic susceptibility (AMS) is now routinely used since more than four decades in the analyses of rock fabrics in granitic rocks (e.g. Stacy 1960, Henry 1975, Gleizes et al. 1993). Even though the intensity of fabrics in granitoids is often weakly developed the significance of orientation and shape of crystals is the same like in other deformed rock types. By revealing the distribution of fabrics in plutonic rocks one of the still ongoing discussions in granite tectonics may be addressed: How did those sometimes voluminous batholiths were inflated in the middle crust? We are presenting magnetic fabric data on a series of Devonian batholiths that intruded the polyphase deformed metaclastites of the Sierra de San Luis (32°100– 33°200 S / 65°150 – 66°200 W) in central Argentina. Regional considerations on the tectonic regime during the emplacement of the batholiths are inferred from combined field, microstructural and AMS observations...conferenc

The Neoproterozoic-early Paleozoic metamorphic and magmatic evolution of the Eastern Sierras Pampeanas: an overview

The Eastern Sierras Pampeanas were structured by three main events: the Ediacaran to early Cambrian (580–510 Ma) Pampean, the late Cambrian–Ordovician (500–440 Ma) Famatinian and the Devonian-Carboniferous (400–350 Ma) Achalian orogenies. Geochronological and Sm–Nd isotopic evidence combined with petrological and structural features allow to speculate for a major rift event (Ediacaran) dividing into two Mesoproterozoic major crustal blocks (source of the Grenvillian age peaks in the metaclastic rocks).This event would be coeval with the development of arc magmatism along the eastern margin of the eastern block. Closure of this eastern margin led to a Cambrian active margin (Sierra Norte arc) along the western margin of the eastern block in which magmatism reworked the same crustal block. Consumption of a ridge segment (input of OIB signature mafic magmas) which controlled granulite-facies metamorphism led to a final collision (Pampean orogeny) with the western Mesoprotrozoic block. Sm–Nd results for the metamorphic basement suggest that the TDM age interval of 1.8–1.7 Ga, which is associated with the less radiogenic values of εNd(540) (−6 to −8), can be considered as the mean average crustal composition for the Eastern Sierras Pampeanas. Increasing metamorphic grade in rocks with similar detrital sources and metamorphic ages like in the Sierras de Córdoba is associated with a younger TDM age and a more positive εNd(540) value. Pampean pre-540 Ma granitoids form two clusters, one with TDM ages between 2.0 and 1.75 Ga and another between 1.6 and 1.5 Ga. Pampean post-540 Ma granitoids exhibit more homogenous TDM ages ranging from 2.0 to 1.75 Ga. Ordovician re-activation of active margin along the western part of the block that collided in the Cambrian led to arc magmatism (Famatinian orogeny) and related ensialic back-arc basin in which high-grade metamorphism is related to mid-crustal felsic plutonism and mafic magmatism with significant contamination of continental crust. TDM values for the Ordovician Famatinian granitoids define a main interval of 1.8–1.6, except for the Ordovician TTG suites of the Sierras de Córdoba, which show younger TDM ages ranging from 1.3 to 1.0 Ga. In Devonian times (Achalian orogeny), a new subduction regime installed west of the Eastern Sierras Pampeanas. Devonian magmatism in the Sierras exhibit process of mixing/assimilation of depleted mantle signature melts and continental crust. Achalian magmatism exhibits more radiogenic εNd(540) values that range between 0.5 and −4 and TDM ages younger than 1.3 Ga. In pre-Devonian times, crustal reworking is dominant, whereas processes during Devonian times involved different geochemical and isotopic signatures that reflect a major input of juvenile magmatism.Fil: Steenken, André. Universität Greifswald; AlemaniaFil: Lopez, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Martínez Dopico, Carmen Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Drobe, Malte. Universität Göttingen; AlemaniaFil: Wemmer, Klaus. Universität Göttingen; AlemaniaFil: Siegesmund, Siegfried. Universität Göttingen; Alemani