7,489 research outputs found
Bell's Inequality and Entanglement in Qubits
We propose an alternative evaluation of quantum entanglement by measuring the
maximum violation of the Bell's inequality without performing a partial trace
operation. This proposal is demonstrated by bridging the maximum violation of
the Bell's inequality and the concurrence of a pure state in an -qubit
system, in which one subsystem only contains one qubit and the state is a
linear combination of two product states. We apply this relation to the ground
states of four qubits in the Wen-Plaquette model and show that they are
maximally entangled. A topological entanglement entropy of the Wen-Plaquette
model could be obtained by relating the upper bound of the maximum violation of
the Bell's inequality to the concurrences of a pure state with respect to
different bipartitions.Comment: 10 page
mmeta: An R Package for Multivariate Meta-Analysis
This paper describes the core features of the R package mmeta, which implements the exact posterior inference of odds ratio, relative risk, and risk difference given either a single 2 x 2 table or multiple 2 x 2 tables when the risks within the same study are independent or correlated
No-reference Point Cloud Geometry Quality Assessment Based on Pairwise Rank Learning
Objective geometry quality assessment of point clouds is essential to
evaluate the performance of a wide range of point cloud-based solutions, such
as denoising, simplification, reconstruction, and watermarking. Existing point
cloud quality assessment (PCQA) methods dedicate to assigning absolute quality
scores to distorted point clouds. Their performance is strongly reliant on the
quality and quantity of subjective ground-truth scores for training, which are
challenging to gather and have been shown to be imprecise, biased, and
inconsistent. Furthermore, the majority of existing objective geometry quality
assessment approaches are carried out by full-reference traditional metrics. So
far, point-based no-reference geometry-only quality assessment techniques have
not yet been investigated. This paper presents PRL-GQA, the first pairwise
learning framework for no-reference geometry-only quality assessment of point
clouds, to the best of our knowledge. The proposed PRL-GQA framework employs a
siamese deep architecture, which takes as input a pair of point clouds and
outputs their rank order. Each siamese architecture branch is a geometry
quality assessment network (GQANet), which is designed to extract multi-scale
quality-aware geometric features and output a quality index for the input point
cloud. Then, based on the predicted quality indexes, a pairwise rank learning
module is introduced to rank the relative quality of a pair of degraded point
clouds.Extensive experiments demonstrate the effectiveness of the proposed
PRL-GQA framework. Furthermore, the results also show that the fine-tuned
no-reference GQANet performs competitively when compared to existing
full-reference geometry quality assessment metrics
Structural study in Highly Compressed BiFeO3 Epitaxial Thin Films on YAlO3
We report a study on the thermodynamic stability and structure analysis of
the epitaxial BiFeO3 (BFO) thin films grown on YAlO3 (YAO) substrate. First we
observe a phase transition of MC-MA-T occurs in thin sample (<60 nm) with an
utter tetragonal-like phase (denoted as MII here) with a large c/a ratio
(~1.23). Specifically, MII phase transition process refers to the structural
evolution from a monoclinic MC structure at room temperature to a monoclinic MA
at higher temperature (150oC) and eventually to a presence of nearly tetragonal
structure above 275oC. This phase transition is further confirmed by the
piezoforce microscopy measurement, which shows the rotation of polarization
axis during the phase transition. A systematic study on structural evolution
with thickness to elucidate the impact of strain state is performed. We note
that the YAO substrate can serve as a felicitous base for growing T-like BFO
because this phase stably exists in very thick film. Thick BFO films grown on
YAO substrate exhibit a typical "morphotropic-phase-boundary"-like feature with
coexisting multiple phases (MII, MI, and R) and a periodic stripe-like
topography. A discrepancy of arrayed stripe morphology in different direction
on YAO substrate due to the anisotropic strain suggests a possibility to tune
the MPB-like region. Our study provides more insights to understand the strain
mediated phase co-existence in multiferroic BFO system.Comment: 18 pages, 6 figures, submitted to Journal of Applied Physic
Fluoroquinolone Resistance in Salmonella enterica Serotype Choleraesuis, Taiwan, 2000–2003
Salmonella enterica serotype Choleraesuis is a highly invasive pathogen that infects humans and causes systemic infections that require antimicrobial therapy. Surveillance in Taiwan showed that fluoroquinolone resistance in S. Choleraesuis markedly increased from 2000 to 2003, reaching approximately 70% in 2003
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