4,292 research outputs found
Testing the anisotropy of the universe using the simulated gravitational wave events from advanced LIGO and Virgo
The detection of gravitational waves (GWs) provides a powerful tool to
constrain the cosmological parameters. In this paper, we investigate the
possibility of using GWs as standard sirens in testing the anisotropy of the
universe. We consider the GW signals produced by the coalescence of binary
black hole systems and simulate hundreds of GW events from the advanced Laser
Interferometer Gravitational-Wave Observatory (LIGO) and Virgo. It is found
that the anisotropy of the universe can be tightly constrained if the redshift
of the GW source is precisely known. The anisotropic amplitude can be
constrained with an accuracy comparable to the Union2.1 complication of type-Ia
supernovae if GW events are observed. As for the preferred
direction, GW events are needed in order to achieve the accuracy
of Union2.1. With 800 GW events, the probability of pseudo anisotropic signals
with an amplitude comparable to Union2.1 is negligible. These results show that
GWs can provide a complementary tool to supernovae in testing the anisotropy of
the universe.Comment: 17 pages, 6 figure
Unsupervised Single Image Deraining with Self-supervised Constraints
Most existing single image deraining methods require learning supervised
models from a large set of paired synthetic training data, which limits their
generality, scalability and practicality in real-world multimedia applications.
Besides, due to lack of labeled-supervised constraints, directly applying
existing unsupervised frameworks to the image deraining task will suffer from
low-quality recovery. Therefore, we propose an Unsupervised Deraining
Generative Adversarial Network (UD-GAN) to tackle above problems by introducing
self-supervised constraints from the intrinsic statistics of unpaired rainy and
clean images. Specifically, we firstly design two collaboratively optimized
modules, namely Rain Guidance Module (RGM) and Background Guidance Module
(BGM), to take full advantage of rainy image characteristics: The RGM is
designed to discriminate real rainy images from fake rainy images which are
created based on outputs of the generator with BGM. Simultaneously, the BGM
exploits a hierarchical Gaussian-Blur gradient error to ensure background
consistency between rainy input and de-rained output. Secondly, a novel
luminance-adjusting adversarial loss is integrated into the clean image
discriminator considering the built-in luminance difference between real clean
images and derained images. Comprehensive experiment results on various
benchmarking datasets and different training settings show that UD-GAN
outperforms existing image deraining methods in both quantitative and
qualitative comparisons.Comment: 10 pages, 8 figure
Recent progress in migraine and cognitive disorder
Migraine is a chronic neurovascular disease characterized by recurrent unilateral headache, which induces incapacity. At present, there are many methods to evaluate cognitive function, and the cognitive function scale is commonly used. Recently, event-related potentials, resting state functional magnetic resonance imaging and other new technologies have been widely used to assess the cognitive function of migraine patients because of their high temporal resolution and high spatial resolution. In this paper, we can overview that the research progress of the relationship between migraine and methods of evaluate cognitive function
Learning Disentangled Feature Representation for Hybrid-distorted Image Restoration
Hybrid-distorted image restoration (HD-IR) is dedicated to restore real
distorted image that is degraded by multiple distortions. Existing HD-IR
approaches usually ignore the inherent interference among hybrid distortions
which compromises the restoration performance. To decompose such interference,
we introduce the concept of Disentangled Feature Learning to achieve the
feature-level divide-and-conquer of hybrid distortions. Specifically, we
propose the feature disentanglement module (FDM) to distribute feature
representations of different distortions into different channels by revising
gain-control-based normalization. We also propose a feature aggregation module
(FAM) with channel-wise attention to adaptively filter out the distortion
representations and aggregate useful content information from different
channels for the construction of raw image. The effectiveness of the proposed
scheme is verified by visualizing the correlation matrix of features and
channel responses of different distortions. Extensive experimental results also
prove superior performance of our approach compared with the latest HD-IR
schemes.Comment: Accepted by ECCV202
Synthesis and evaluation of a novel fluorescent sensor based on hexahomotrioxacalix[3]arene for ZnĀ²+ and CdĀ²+
A novel type of selective and sensitive fluorescent sensor having triazole rings as the binding sites on the lower rim of a hexahomotrioxacalix[3]arene scaffold in a cone conformation is reported. This sensor has desirable properties for practical applications, including selectivity for detecting ZnĀ²āŗ and CdĀ²āŗ in the presence of excess competing metal ions at low ion concentration or as a fluorescence enhancement type chemosensor due to the cavity of calixarene changing from a āflattened-coneā to a more-upright form and inhibition of PET. In contrast, the results suggested that receptor 1 is highly sensitive and selective for CuĀ²āŗ and FeĀ³āŗ as a fluorescence quenching type chemosensor due to the photoinduced electron transfer (PET) or heavy atom effect
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