886 research outputs found
Enriching Knowledge Bases with Counting Quantifiers
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
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
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
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 possĂveis implicações climáticas.
Resumo: As tecnologias usadas na produção somada Ă variabilidade climática podem explicar grande parte das flutuações nos rendimentos de grĂŁos de soja em diferentes safras agrĂcolas. Assim, o objetivo deste trabalho foi analisar o rendimento de grĂŁos de soja, em diferentes condições de disponibilidade hĂdrica 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 mĂ©dias das duas safras foi de 7,2 %. Na safra 2006/2007 as chuvas foram bem distribuĂdas, 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
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 eV 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 e/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.
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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