5,523 research outputs found
Chiral Logarithms in Kaon Decay Amplitudes in General Effective Flavor Theories
We study the chiral logarithms in kaon decay amplitudes from new
flavor physics in beyond-standard-model theories. We systematically classify
the chiral structures of dimension-5, 6 and 7 effective QCD operators
constructed out of light-quark (up, down and strange) and gluon fields. Using
the standard chiral perturbation theory, we calculate the leading
chiral-logarithms associated with these operators. The result is useful for
lattice calculations of the QCD matrix elements in decay
necessary, for example, to understand the physical origin of the direct CP
violation parameter . As a concrete example, we consider the new
operators present in minimal left-right symmetric models
Signatures of Bose-Einstein condensation in an optical lattice
We discuss typical experimental signatures for the Bose-Einstein condensation
(BEC) of an ultracold Bose gas in an inhomogeneous optical lattice at finite
temperature. Applying the Hartree-Fock-Bogoliubov-Popov formalism, we calculate
quantities such as the momentum-space density distribution, visibility and peak
width as the system is tuned through the superfluid to normal phase transition.
Different from previous studies, we consider systems with fixed total particle
number, which is of direct experimental relevance. We show that the onset of
BEC is accompanied by sharp features in all these signatures, which can be
probed via typical time-of-flight imaging techniques. In particular, we find a
two-platform structure in the peak width across the phase transition. We show
that the onset of condensation is related to the emergence of the higher
platform, which can be used as an effective experimental signature.Comment: 5 pages, 3 figure
CamoDiffusion: Camouflaged Object Detection via Conditional Diffusion Models
Camouflaged Object Detection (COD) is a challenging task in computer vision
due to the high similarity between camouflaged objects and their surroundings.
Existing COD methods primarily employ semantic segmentation, which suffers from
overconfident incorrect predictions. In this paper, we propose a new paradigm
that treats COD as a conditional mask-generation task leveraging diffusion
models. Our method, dubbed CamoDiffusion, employs the denoising process of
diffusion models to iteratively reduce the noise of the mask. Due to the
stochastic sampling process of diffusion, our model is capable of sampling
multiple possible predictions from the mask distribution, avoiding the problem
of overconfident point estimation. Moreover, we develop specialized learning
strategies that include an innovative ensemble approach for generating robust
predictions and tailored forward diffusion methods for efficient training,
specifically for the COD task. Extensive experiments on three COD datasets
attest the superior performance of our model compared to existing
state-of-the-art methods, particularly on the most challenging COD10K dataset,
where our approach achieves 0.019 in terms of MAE
Balancing Augmentation with Edge-Utility Filter for Signed GNNs
Signed graph neural networks (SGNNs) has recently drawn more attention as
many real-world networks are signed networks containing two types of edges:
positive and negative. The existence of negative edges affects the SGNN
robustness on two aspects. One is the semantic imbalance as the negative edges
are usually hard to obtain though they can provide potentially useful
information. The other is the structural unbalance, e.g. unbalanced triangles,
an indication of incompatible relationship among nodes. In this paper, we
propose a balancing augmentation method to address the above two aspects for
SGNNs. Firstly, the utility of each negative edge is measured by calculating
its occurrence in unbalanced structures. Secondly, the original signed graph is
selectively augmented with the use of (1) an edge perturbation regulator to
balance the number of positive and negative edges and to determine the ratio of
perturbed edges to original edges and (2) an edge utility filter to remove the
negative edges with low utility to make the graph structure more balanced.
Finally, a SGNN is trained on the augmented graph which effectively explores
the credible relationships. A detailed theoretical analysis is also conducted
to prove the effectiveness of each module. Experiments on five real-world
datasets in link prediction demonstrate that our method has the advantages of
effectiveness and generalization and can significantly improve the performance
of SGNN backbones.Comment: 16 page
Design And Fabrication of Condenser Microphone Using Wafer Transfer And Micro-electroplating Technique
A novel fabrication process, which uses wafer transfer and
micro-electroplating technique, has been proposed and tested. In this paper,
the effects of the diaphragm thickness and stress, the air-gap thickness, and
the area ratio of acoustic holes to backplate on the sensitivity of the
condenser microphone have been demonstrated since the performance of the
microphone depends on these parameters. The microphone diaphragm has been
designed with a diameter and thickness of 1.9 mm and 0.6 m, respectively,
an air-gap thickness of 10 m, and a 24% area ratio of acoustic holes to
backplate. To obtain a lower initial stress, the material used for the
diaphragm is polyimide. The measured sensitivities of the microphone at the
bias voltages of 24 V and 12 V are -45.3 and -50.2 dB/Pa (at 1 kHz),
respectively. The fabricated microphone shows a flat frequency response
extending to 20 kHz.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Chinese Herb and Formulas for Promoting Blood Circulation and Removing Blood Stasis and Antiplatelet Therapies
Atherothrombosis, which directly threatens people's health and lives, is the main cause of morbidity and mortality all over the world. Platelets play a key role in the development of acute coronary syndromes (ACSs) and contribute to cardiovascular events. Oral antiplatelet drugs are a milestone in the therapy of cardiovascular atherothrombotic diseases. In recent years, many reports have shown the possibility that “resistance” to oral anti-platelet drugs and many adverse reactions, such as serious bleeding risk, which provides an impetus for developing new anti-platelet drugs possesses highly efficiency and fewer adverse effects. Study on the blood stasis syndrome and promoting blood circulation and removing blood stasis is the most active field of research of integration of traditional and western medicine in China. Blood-stasis syndrome and platelet activation have close relationship, many Chinese herb and formulas for promoting blood circulation and removing blood stasis possess definite anti-platelet effect. This paper covers the progress of anti-platelet mechanism of Chinese herb and formulas for promoting blood circulation and removing blood stasis and is to be deeply discussed in further research
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