13,705 research outputs found
Measuring Accuracy of Triples in Knowledge Graphs
An increasing amount of large-scale knowledge graphs have been constructed in recent years. Those graphs are often created from text-based extraction, which could be very noisy. So far, cleaning knowledge graphs are often carried out by human experts and thus very inefficient. It is necessary to explore automatic methods for identifying and eliminating erroneous information. In order to achieve this, previous approaches primarily rely on internal information i.e. the knowledge graph itself. In this paper, we introduce an automatic approach, Triples Accuracy Assessment (TAA), for validating RDF triples (source triples) in a knowledge graph by finding consensus of matched triples (among target triples) from other knowledge graphs. TAA uses knowledge graph interlinks to find identical resources and apply different matching methods between the predicates of source triples and target triples. Then based on the matched triples, TAA calculates a confidence score to indicate the correctness of a source triple. In addition, we present an evaluation of our approach using the FactBench dataset for fact validation. Our findings show promising results for distinguishing between correct and wrong triples
Pregnancy-associated breast cancer - Special features in diagnosis and treatment
For obvious psychological reasons it is difficult to associate pregnancy - a life-giving period of our existence with life-threatening malignancies. Symptoms pointing to malignancy are often ignored by both patients and physicians, and this, together with the greater difficulty of diagnostic imaging, probably results in the proven delay in the detection of breast cancers during pregnancy. The diagnosis and treatment of breast cancer are becoming more and more important, as the fulfillment of the desire to have children is increasingly postponed until a later age associated with a higher risk of carcinoma, and improved cure rates of solid tumors no longer exclude subsequent pregnancies. The following article summarizes the special features of the diagnosis and primary therapy of pregnancy-associated breast cancer with particular consideration of cytostatic therapy
Chiral Symmetry Restoration at Finite Temperature in the Linear Sigma--Model
The temperature behaviour of meson condensates
is calculated in the -linear sigma model. The couplings of
the Lagrangian are fitted to the physical masses, the pion
decay constant and a scalar mass of GeV. The quartic
terms of the mesonic interaction are converted to a quadratic term with the
help of a Hubbard-Stratonovich transformation. Effective mass terms are
generated this way, which are treated self-consistently to leading order of a
-expansion. We calculate the light and strange -quark condensates using PCAC relations between the meson masses and
condensates. For a cut-off value of 1.5 GeV we find a first-order chiral
transition at a critical temperature MeV. At this temperature the
spontaneously broken subgroup is restored. Entropy density,
energy density and pressure are calculated for temperatures up to and slightly
above the critical temperature. To our surprise we find some indications for a
reduced contribution from strange mesons for .Comment: 17 pages, HD--TVP--93--15. (3 figures - available on request
Microscopic Model versus Systematic Low-Energy Effective Field Theory for a Doped Quantum Ferromagnet
We consider a microscopic model for a doped quantum ferromagnet as a test
case for the systematic low-energy effective field theory for magnons and
holes, which is constructed in complete analogy to the case of quantum
antiferromagnets. In contrast to antiferromagnets, for which the effective
field theory approach can be tested only numerically, in the ferromagnetic case
both the microscopic and the effective theory can be solved analytically. In
this way the low-energy parameters of the effective theory are determined
exactly by matching to the underlying microscopic model. The low-energy
behavior at half-filling as well as in the single- and two-hole sectors is
described exactly by the systematic low-energy effective field theory. In
particular, for weakly bound two-hole states the effective field theory even
works beyond perturbation theory. This lends strong support to the quantitative
success of the systematic low-energy effective field theory method not only in
the ferromagnetic but also in the physically most interesting antiferromagnetic
case.Comment: 34 pages, 1 figur
Dominant g(9/2)^2 neutron configuration in the 4+1 state of 68Zn based on new g factor measurements
The factor of the state in Zn has been remeasured with
improved energy resolution of the detectors used. The value obtained is
consistent with the previous result of a negative factor thus confirming
the dominant neutron nature of the state. In addition, the
accuracy of the factors of the , and states has been
improved an d their lifetimes were well reproduced. New large-scale shell model
calculations based on a Ni core and an model space
yield a theoretical value, . Although the calculated value
is small, it cannot fully explain the experimental value, . The magnitude of the deduced B(E2) of the and
transition is, however, rather well described. These results demonstrate again
the importance of factor measurements for nuclear structure determination s
due to their specific sensitivity to detailed proton and neutron components in
the nuclear wave functions.Comment: 7 pages, 3 figs, submitted to PL
Transverse laser cooling of a thermal atomic beam of dysprosium
A thermal atomic beam of dysprosium (Dy) atoms is cooled using the
transition at 421 nm. The cooling is
done via a standing light wave orthogonal to the atomic beam. Efficient
transverse cooling to the Doppler limit is demonstrated for all observable
isotopes of dysprosium. Branching ratios to metastable states are demonstrated
to be . A scheme for enhancement of the
nonzero-nuclear-spin-isotope cooling, as well as a method for direct
identification of possible trap states, is proposed.Comment: 5 pages, 4 figures v2: 7 pages, 7 figure
On the Deconfinement Phase Transition in the Resonance Gas
We obtain the constraints on the ruling parameters of the dense hadronic gas
model at the critical temperature and propose the quasiuniversal ratios of the
thermodynamic quantities. The possible appearence of thermodynamical
instability in such a model is discussed.Comment: 7 pages, plain LaTeX, BI-TP 94/4
Entrainment rates and microphysics in POST stratocumulus
The article of record as published may be located at http://dx.doi.org/10.1002/jgrd.50878An aircraft field study (POST; Physics of Stratocumulus Top) was conducted off the
central California coast in July and August 2008 to deal with the known difficulty of
measuring entrainment rates in the radiatively important stratocumulus (Sc) prevalent in that
area. The Center for Interdisciplinary Remotely-Piloted Aircraft Studies Twin Otter
research aircraft flew 15 quasi-Lagrangian flights in unbroken Sc and carried a full
complement of probes including three high-data-rate probes: ultrafast temperature probe,
particulate volume monitor probe, and gust probe. The probes’ colocation near the nose of
the Twin Otter permitted estimation of entrainment fluxes and rates with an in-cloud
resolution of 1m. Results include the following: Application of the conditional sampling
variation of classical mixed layer theory for calculating the entrainment rate into cloud top
for POST flights is shown to be inadequate for most of the Sc. Estimated rates resemble
previous results after theory is modified to take into account both entrainment and
evaporation at cloud top given the strong wind shear and mixing at cloud top. Entrainment
rates show a tendency to decrease for large shear values, and the largest rates are for the
smallest temperature jumps across the inversion. Measurements indirectly suggest that
entrained parcels are primarily cooled by infrared flux divergence rather than cooling from
droplet evaporation, while detrainment at cloud top causes droplet evaporation and cooling
in the entrainment interface layer above cloud top.NSF supported H. Gerber, G. Frick, and S. Malinowski (ATM-0735121, AGS-1020445), D. Khelif (ATM-0734323), and S. Krueger (ATM-0735118). The Office of Naval Research and the Naval Postgraduate School supported in part the deployment of the Twin Otter aircraft
Anisotropic thermal expansion and magnetostriction of YNiBC single crystals
We present results of anisotropic thermal expansion and low temperature
magnetostriction measurements on YNiBC single crystals grown by high
temperature flux and floating zone techniques. Quantum oscillations of
magnetostriction were observed at low temperatures for starting at
fields significantly below (). Large irreversible,
longitudinal magnetostriction was seen in both, in-plane and along the c-axis,
directions of the applied magnetic field in the intermediate superconducting
state. Anisotropic uniaxial pressure dependencies of were evaluated using
results of zero field, thermal expansion measurements
Pressure-Induced Rotational Symmetry Breaking in URuSi
Phase transitions and symmetry are intimately linked. Melting of ice, for
example, restores translation invariance. The mysterious hidden order (HO)
phase of URuSi has, despite relentless research efforts, kept its
symmetry breaking element intangible. Here we present a high-resolution x-ray
diffraction study of the URuSi crystal structure as a function of
hydrostatic pressure. Below a critical pressure threshold kbar,
no tetragonal lattice symmetry breaking is observed even below the HO
transition K. For , however, a pressure-induced rotational
symmetry breaking is identified with an onset temperatures K.
The emergence of an orthorhombic phase is found and discussed in terms of an
electronic nematic order that appears unrelated to the HO, but with possible
relevance for the pressure-induced antiferromagnetic (AF) phase. Existing
theories describe the HO and AF phases through an adiabatic continuity of a
complex order parameter. Since none of these theories predicts a
pressure-induced nematic order, our finding adds an additional symmetry
breaking element to this long-standing problem.Comment: 6 pages, 4 figures and supplemental material
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