603 research outputs found
Cross-Domain Local Characteristic Enhanced Deepfake Video Detection
As ultra-realistic face forgery techniques emerge, deepfake detection has
attracted increasing attention due to security concerns. Many detectors cannot
achieve accurate results when detecting unseen manipulations despite excellent
performance on known forgeries. In this paper, we are motivated by the
observation that the discrepancies between real and fake videos are extremely
subtle and localized, and inconsistencies or irregularities can exist in some
critical facial regions across various information domains. To this end, we
propose a novel pipeline, Cross-Domain Local Forensics (XDLF), for more general
deepfake video detection. In the proposed pipeline, a specialized framework is
presented to simultaneously exploit local forgery patterns from space,
frequency, and time domains, thus learning cross-domain features to detect
forgeries. Moreover, the framework leverages four high-level forgery-sensitive
local regions of a human face to guide the model to enhance subtle artifacts
and localize potential anomalies. Extensive experiments on several benchmark
datasets demonstrate the impressive performance of our method, and we achieve
superiority over several state-of-the-art methods on cross-dataset
generalization. We also examined the factors that contribute to its performance
through ablations, which suggests that exploiting cross-domain local
characteristics is a noteworthy direction for developing more general deepfake
detectors
Throughput Maximization Leveraging Just-Enough SNR Margin and Channel Spacing Optimization
Flexible optical network is a promising technology to accommodate
high-capacity demands in next-generation networks. To ensure uninterrupted
communication, existing lightpath provisioning schemes are mainly done with the
assumption of worst-case resource under-provisioning and fixed channel spacing,
which preserves an excessive signal-to-noise ratio (SNR) margin. However, under
a resource over-provisioning scenario, the excessive SNR margin restricts the
transmission bit-rate or transmission reach, leading to physical layer resource
waste and stranded transmission capacity. To tackle this challenging problem,
we leverage an iterative feedback tuning algorithm to provide a just-enough SNR
margin, so as to maximize the network throughput. Specifically, the proposed
algorithm is implemented in three steps. First, starting from the high SNR
margin setup, we establish an integer linear programming model as well as a
heuristic algorithm to maximize the network throughput by solving the problem
of routing, modulation format, forward error correction, baud-rate selection,
and spectrum assignment. Second, we optimize the channel spacing of the
lightpaths obtained from the previous step, thereby increasing the available
physical layer resources. Finally, we iteratively reduce the SNR margin of each
lightpath until the network throughput cannot be increased. Through numerical
simulations, we confirm the throughput improvement in different networks and
with different baud-rates. In particular, we find that our algorithm enables
over 20\% relative gain when network resource is over-provisioned, compared to
the traditional method preserving an excessive SNR margin.Comment: submitted to IEEE JLT, Jul. 17th, 2021. 14 pages, 8 figure
TF-ICON: Diffusion-Based Training-Free Cross-Domain Image Composition
Text-driven diffusion models have exhibited impressive generative
capabilities, enabling various image editing tasks. In this paper, we propose
TF-ICON, a novel Training-Free Image COmpositioN framework that harnesses the
power of text-driven diffusion models for cross-domain image-guided
composition. This task aims to seamlessly integrate user-provided objects into
a specific visual context. Current diffusion-based methods often involve costly
instance-based optimization or finetuning of pretrained models on customized
datasets, which can potentially undermine their rich prior. In contrast,
TF-ICON can leverage off-the-shelf diffusion models to perform cross-domain
image-guided composition without requiring additional training, finetuning, or
optimization. Moreover, we introduce the exceptional prompt, which contains no
information, to facilitate text-driven diffusion models in accurately inverting
real images into latent representations, forming the basis for compositing. Our
experiments show that equipping Stable Diffusion with the exceptional prompt
outperforms state-of-the-art inversion methods on various datasets (CelebA-HQ,
COCO, and ImageNet), and that TF-ICON surpasses prior baselines in versatile
visual domains. Code is available at https://github.com/Shilin-LU/TF-ICONComment: Accepted by ICCV202
Integrated metagenomics and metabolomics analysis reveals changes in the microbiome and metabolites in the rhizosphere soil of Fritillaria unibracteata
Fritillaria unibracteata (FU) is a renowned herb in China that requires strict growth conditions in its cultivation process. During this process, the soil microorganisms and their metabolites may directly affect the growth and development of FU, for example, the pathogen infection and sipeimine production. However, few systematic studies have reported the changes in the microbiome and metabolites during FU cultivation thus far. In this work, we simultaneously used metagenomics and metabolomics technology to monitor the changes in microbial communities and metabolites in the rhizosphere of FU during its cultivation for one, two, and three years. Moreover, the interaction between microorganisms and metabolites was investigated by co-occurrence network analysis. The results showed that the microbial composition between the three cultivation-year groups was significantly different (2020-2022). The dominant genera changed from Pseudomonas and Botrytis in CC1 to Mycolicibacterium and Pseudogymnoascus in CC3. The relative abundances of beneficial microorganisms decreased, while the relative abundances of harmful microorganisms showed an increasing trend. The metabolomics results showed that significant changes of the of metabolite composition were observed in the rhizosphere soil, and the relative abundances of some beneficial metabolites showed a decreasing trend. In this study, we discussed the changes in the microbiome and metabolites during the three-year cultivation of FU and revealed the relationship between microorganisms and metabolites. This work provides a reference for the efficient and sustainable cultivation of FU
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