886 research outputs found

    Enriching Knowledge Bases with Counting Quantifiers

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    Information extraction traditionally focuses on extracting relations between identifiable entities, such as . Yet, texts often also contain Counting information, stating that a subject is in a specific relation with a number of objects, without mentioning the objects themselves, for example, "California is divided into 58 counties". Such counting quantifiers can help in a variety of tasks such as query answering or knowledge base curation, but are neglected by prior work. This paper develops the first full-fledged system for extracting counting information from text, called CINEX. We employ distant supervision using fact counts from a knowledge base as training seeds, and develop novel techniques for dealing with several challenges: (i) non-maximal training seeds due to the incompleteness of knowledge bases, (ii) sparse and skewed observations in text sources, and (iii) high diversity of linguistic patterns. Experiments with five human-evaluated relations show that CINEX can achieve 60% average precision for extracting counting information. In a large-scale experiment, we demonstrate the potential for knowledge base enrichment by applying CINEX to 2,474 frequent relations in Wikidata. CINEX can assert the existence of 2.5M facts for 110 distinct relations, which is 28% more than the existing Wikidata facts for these relations.Comment: 16 pages, The 17th International Semantic Web Conference (ISWC 2018

    Weak localization in ferromagnetic (Ga,Mn)As nanostructures

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    We report on the observation of weak localization in arrays of (Ga,Mn)As nanowires at millikelvin temperatures. The corresponding phase coherence length is typically between 100 nm and 200 nm at 20 mK. Strong spin-orbit interaction in the material is manifested by a weak anti-localization correction around zero magnetic field.Comment: 5 pages, 3 figure

    Analysis of ultrasonic transducers with fractal architecture

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    Ultrasonic transducers composed of a periodic piezoelectric composite are generally accepted as the design of choice in many applications. Their architecture is normally very regular and this is due to manufacturing constraints rather than performance optimisation. Many of these manufacturing restrictions no longer hold due to new production methods such as computer controlled, laser cutting, and so there is now freedom to investigate new types of geometry. In this paper, the plane wave expansion model is utilised to investigate the behaviour of a transducer with a self-similar architecture. The Cantor set is utilised to design a 2-2 conguration, and a 1-3 conguration is investigated with a Sierpinski Carpet geometry

    Phase coherent transport in (Ga,Mn)As

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    Quantum interference effects and resulting quantum corrections of the conductivity have been intensively studied in disordered conductors over the last decades. The knowledge of phase coherence lengths and underlying dephasing mechanisms are crucial to understand quantum corrections to the resistivity in the different material systems. Due to the internal magnetic field and the associated breaking of time-reversal symmetry quantum interference effects in ferromagnetic materials have been scarcely explored. Below we describe the investigation of phase coherent transport phenomena in the newly discovered ferromagnetic semiconductor (Ga,Mn)As. We explore universal conductance fluctuations in mesoscopic (Ga,Mn)As wires and rings, the Aharonov-Bohm effect in nanoscale rings and weak localization in arrays of wires, made of the ferromagnetic semiconductor material. The experiments allow to probe the phase coherence length L_phi and the spin flip length L_SO as well as the temperature dependence of dephasing.Comment: 22 pages, 10 figure

    Análise do rendimento de soja e possíveis implicações climáticas.

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    Resumo: As tecnologias usadas na produção somada à variabilidade climática podem explicar grande parte das flutuações nos rendimentos de grãos de soja em diferentes safras agrícolas. Assim, o objetivo deste trabalho foi analisar o rendimento de grãos de soja, em diferentes condições de disponibilidade hídrica no solo. Para tanto, os experimentos foram conduzidos no campo experimental da Embrapa Soja ? Londrina (PR), durante as safras 2005/2006 e 2006/2007. A diferença entre as médias das duas safras foi de 7,2 %. Na safra 2006/2007 as chuvas foram bem distribuídas, resultando em melhor desenvolvimento das plantas e, consequentemente, favorecendo rendimentos ligeiramente maiores do que na safra anterior. Analysis of soybean yiel and possible climate implications. The technologies used in the production coupled with the climate variability can explain most of the fluctuations in the yield of soybean in different years. So, the objective of this research was to analyze the yield of soybean under different soil water availability. For this, experiments were conducted at Embrapa Soja - Londrina (PR) during the 2005/2006 and 2006/2007 seasons. The difference between the means of two seasons was 7.2%. In 2006/2007 season the rains were well distributed, resulting in better plant growth, thus slightly favoring higher yields than the in the previous season

    Observation of the spin-orbit gap in bilayer graphene by one-dimensional ballistic transport

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    We report on measurements of quantized conductance in gate-defined quantum point contacts in bilayer graphene that allow the observation of subband splittings due to spin-orbit coupling. The size of this splitting can be tuned from 40 to 80 ÎĽ\mueV by the displacement field. We assign this gate-tunable subband-splitting to a gap induced by spin-orbit coupling of Kane-Mele type, enhanced by proximity effects due to the substrate. We show that this spin-orbit coupling gives rise to a complex pattern in low perpendicular magnetic fields, increasing the Zeeman splitting in one valley and suppressing it in the other one. In addition, we observe the existence of a spin-polarized channel of 6 e2^2/h at high in-plane magnetic field and of signatures of interaction effects at the crossings of spin-split subbands of opposite spins at finite magnetic field.Comment: 5 pages, 4 figures, Supplement 6 figure

    Sintomas e diagnose de fitotoxicidade de herbicidas na cultura da soja.

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    Fitotoxicidade; Diagnose de fitotoxicidade; Sintomas de fitotoxicidade; Danos causados por outros fatores; Relacao de herbicidas por grupo quimico.bitstream/item/23231/1/Doc13.pd
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