2,156 research outputs found
LFS-GAN: Lifelong Few-Shot Image Generation
We address a challenging lifelong few-shot image generation task for the
first time. In this situation, a generative model learns a sequence of tasks
using only a few samples per task. Consequently, the learned model encounters
both catastrophic forgetting and overfitting problems at a time. Existing
studies on lifelong GANs have proposed modulation-based methods to prevent
catastrophic forgetting. However, they require considerable additional
parameters and cannot generate high-fidelity and diverse images from limited
data. On the other hand, the existing few-shot GANs suffer from severe
catastrophic forgetting when learning multiple tasks. To alleviate these
issues, we propose a framework called Lifelong Few-Shot GAN (LFS-GAN) that can
generate high-quality and diverse images in lifelong few-shot image generation
task. Our proposed framework learns each task using an efficient task-specific
modulator - Learnable Factorized Tensor (LeFT). LeFT is rank-constrained and
has a rich representation ability due to its unique reconstruction technique.
Furthermore, we propose a novel mode seeking loss to improve the diversity of
our model in low-data circumstances. Extensive experiments demonstrate that the
proposed LFS-GAN can generate high-fidelity and diverse images without any
forgetting and mode collapse in various domains, achieving state-of-the-art in
lifelong few-shot image generation task. Surprisingly, we find that our LFS-GAN
even outperforms the existing few-shot GANs in the few-shot image generation
task. The code is available at Github.Comment: 20 pages, 19 figures, 14 tables, ICCV 2023 Poste
Perception-Oriented Single Image Super-Resolution using Optimal Objective Estimation
Single-image super-resolution (SISR) networks trained with perceptual and
adversarial losses provide high-contrast outputs compared to those of networks
trained with distortion-oriented losses, such as L1 or L2. However, it has been
shown that using a single perceptual loss is insufficient for accurately
restoring locally varying diverse shapes in images, often generating
undesirable artifacts or unnatural details. For this reason, combinations of
various losses, such as perceptual, adversarial, and distortion losses, have
been attempted, yet it remains challenging to find optimal combinations. Hence,
in this paper, we propose a new SISR framework that applies optimal objectives
for each region to generate plausible results in overall areas of
high-resolution outputs. Specifically, the framework comprises two models: a
predictive model that infers an optimal objective map for a given
low-resolution (LR) input and a generative model that applies a target
objective map to produce the corresponding SR output. The generative model is
trained over our proposed objective trajectory representing a set of essential
objectives, which enables the single network to learn various SR results
corresponding to combined losses on the trajectory. The predictive model is
trained using pairs of LR images and corresponding optimal objective maps
searched from the objective trajectory. Experimental results on five benchmarks
show that the proposed method outperforms state-of-the-art perception-driven SR
methods in LPIPS, DISTS, PSNR, and SSIM metrics. The visual results also
demonstrate the superiority of our method in perception-oriented
reconstruction. The code and models are available at
https://github.com/seungho-snu/SROOE.Comment: Code and trained models will be available at
https://github.com/seungho-snu/SROO
Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.
Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH
The Occurrence and Speed of CMEs Related to Two Characteristic Evolution Patterns of Helicity Injection in Their Solar Source Regions
Long-term (a few days) variation of magnetic helicity injection was
calculated for 28 solar active regions which produced 47 CMEs to find its
relationships with the CME occurrence and speed using SOHO/MDI line-of-sight
magnetograms. As a result, we found that the 47 CMEs can be categorized into
two different groups by two characteristic evolution patterns of helicity
injection in their source active regions which appeared for about 0.5-4.5 days
before their occurrence: (1) a monotonically increasing pattern with one sign
of helicity (Group A; 30 CMEs in 23 active regions) and (2) a pattern of
significant helicity injection followed by its sign reversal (Group B; 17 CMEs
in 5 active regions). We also found that CME speed has a correlation with
average helicity injection rate with linear correlation coefficients of 0.85
and 0.63 for Group A and Group B, respectively. In addition, these two CME
groups show different characteristics as follows: (1) the average CME speed of
Group B (1330km/s) is much faster than that of Group A (870km/s), (2) the CMEs
in Group A tend to be single events, whereas those in Group B mainly consist of
successive events, and (3) flares related to the CMEs in Group B are relatively
more energetic and impulsive than those in Group A. Our findings therefore
suggest that the two CME groups have different pre-CME conditions in their
source active regions and different CME characteristics.Comment: 25 pages, 7 figures, accepted for publication in Ap
Anti-malarial activity of 6-(8'Z-pentadecenyl)-salicylic acid from Viola websteri in mice
<p>Abstract</p> <p>Background</p> <p>Petroleum ether extracts of <it>Viola websteri </it>Hemsl (Violaceae) were reported to have anti-plasmodial activity against <it>Plasmodium falciparum in vitro</it>, with this activity being largely attributable to 6-(8'Z-pentadecenyl)-salicylic acid (6-SA).</p> <p>Methods</p> <p>The schizontocidal activity of 6-SA on early <it>Plasmodium berghei </it>infections was evaluated in a four-day test. The possible 'repository' activity of 6-SA was assessed using the method described by Peters. The median lethal dose (LD<sub>50</sub>) of 6-SA, when given intraperitoneally, was also determined using uninfected ICR mice and the method of Lorke.</p> <p>Results</p> <p>In the present study, 6-SA was found to have anti-malarial activity <it>in vivo</it>, when tested against <it>P. berghei </it>in mice. 6-SA at 5, 10 and 25 mg/kg·day exhibited a significant blood schizontocidal activity in four-day early infections, repository evaluations and established infections with a significant mean survival time comparable to that of the standard drug, chloroquine (5 mg/kg·day).</p> <p>Conclusion</p> <p>6-SA possesses a moderate anti-malarial activity that could be exploited for malaria therapy.</p
CdSe quantum dot (QD) and molecular dye hybrid sensitizers for TiO2 mesoporous solar cells: working together with a common hole carrier of cobalt complexes
Redox couples based on cobalt complexes were found to be effective in regenerating both inorganic CdSe quantum dot-and organic dye-sensitizers. The hybrid sensitizer composed of CdSe QD and ruthenium sensitizer (Z907Na) dye showed a maximum power conversion efficiency of 4.76% on using cobalt(o-phen)(3)(2+/3+) as a common redox mediator.close202
Tempcore Process Simulator to Analyze Microstructural Evolution of Quenched and Tempered Rebar
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Proposed process simulator can be widely applied to parameter design of industrial Tempcore process with reduced cost and time.
Abstract Tempcore process simulator (TPS) has been developed in this study to analyze the microstructural evolution of quenched and tempered rebar. There has been an increasing need to relate the complex microstructures to the resulting properties of quenched and tempered rebar. However, information on such relationships typically requires precise thermal histories imposed on the workpiece. Therefore, TPS, capable of simulating the Tempcore process, has been developed to produce high-fidelity data. TPS mainly consists of a vacuum induction furnace, pilot rolling mill, box furnace, and cooling unit to simulate shop floor operations. A series of experimental tests were successfully carried out with various parameters, such as reheating temperature, water flow, water pressure, and cooling time. The effects of chemical compositions and cooling time on the microstructural evolution and mechanical properties of quenched and tempered rebar have been analyzed to validate the performance of TPS. The results show that TPS can simulate the Tempcore process with a high degree of fidelity and reliability.11Ysciescopu
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