13,984 research outputs found
Medical Image Segmentation Based on Multi-Modal Convolutional Neural Network: Study on Image Fusion Schemes
Image analysis using more than one modality (i.e. multi-modal) has been
increasingly applied in the field of biomedical imaging. One of the challenges
in performing the multimodal analysis is that there exist multiple schemes for
fusing the information from different modalities, where such schemes are
application-dependent and lack a unified framework to guide their designs. In
this work we firstly propose a conceptual architecture for the image fusion
schemes in supervised biomedical image analysis: fusing at the feature level,
fusing at the classifier level, and fusing at the decision-making level.
Further, motivated by the recent success in applying deep learning for natural
image analysis, we implement the three image fusion schemes above based on the
Convolutional Neural Network (CNN) with varied structures, and combined into a
single framework. The proposed image segmentation framework is capable of
analyzing the multi-modality images using different fusing schemes
simultaneously. The framework is applied to detect the presence of soft tissue
sarcoma from the combination of Magnetic Resonance Imaging (MRI), Computed
Tomography (CT) and Positron Emission Tomography (PET) images. It is found from
the results that while all the fusion schemes outperform the single-modality
schemes, fusing at the feature level can generally achieve the best performance
in terms of both accuracy and computational cost, but also suffers from the
decreased robustness in the presence of large errors in any image modalities.Comment: Zhe Guo and Xiang Li contribute equally to this wor
O-operators on associative algebras and associative Yang–Baxter equations
An O-operator on an associative algebra is a generalization of a Rota–Baxter operator that plays an important role in the Hopf algebra approach of Connes and Kreimer to the renormalization of quantum field theory. It is also the associative analog of an O-operator on a Lie algebra in the study of the classical Yang–Baxter equation. We introduce the concept of an extended O-operator on an associative algebra whose Lie algebra analog has been applied to generalized Lax pairs and PostLie algebras. We study algebraic structures coming from extended O-operators. Continuing the work of Aguiar deriving Rota–Baxter operators from the associative Yang–Baxter equation, we show that its solutions correspond to extended O-operators through a duality. We also establish a relationship of extended O-operators with the generalized associative Yang–Baxter equation
Teleporting a rotation on remote photons
Quamtum remote rotation allows implement local quantum operation on remote
systems with shared entanglement. Here we report an experimental demonstration
of remote rotation on single photons using linear optical element. And the
local dephase is also teleported during the process. The scheme can be
generalized to any controlled rotation commutes with .Comment: 5 pages, 4 figure
Annihilation Rates of Heavy S-wave Quarkonia in Salpeter Method
The annihilation rates of vector charmonium and bottomonium
states and , and are estimated in the relativistic Salpeter method.
We obtained keV,
keV,
keV,
keV,
keV,
keV and
keV. In our
calculations, special attention is paid to the relativistic correction, which
is important and can not be ignored for excited , and higher excited
states.Comment: 10 pages,2 figures, 5 table
Achieving quantum precision limit in adaptive qubit state tomography
The precision limit in quantum state tomography is of great interest not only
to practical applications but also to foundational studies. However, little is
known about this subject in the multiparameter setting even theoretically due
to the subtle information tradeoff among incompatible observables. In the case
of a qubit, the theoretic precision limit was determined by Hayashi as well as
Gill and Massar, but attaining the precision limit in experiments has remained
a challenging task. Here we report the first experiment which achieves this
precision limit in adaptive quantum state tomography on optical polarization
qubits. The two-step adaptive strategy employed in our experiment is very easy
to implement in practice. Yet it is surprisingly powerful in optimizing most
figures of merit of practical interest. Our study may have significant
implications for multiparameter quantum estimation problems, such as quantum
metrology. Meanwhile, it may promote our understanding about the
complementarity principle and uncertainty relations from the information
theoretic perspective.Comment: 9 pages, 4 figures; titles changed and structure reorganise
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