165 research outputs found
A sharp bound for the resurgence of sums of ideals
We prove a sharp upper bound for the resurgence of sums of ideals involving
disjoint sets of variables, strengthening work of
Bisui--H\`a--Jayanthan--Thomas. Complete solutions are delivered for two
conjectures proposed by these authors. For given real numbers and , we
consider the set Res of possible values of the resurgence of where
and are ideals in disjoint sets of variables having resurgence and
, respectively. Some questions and partial results about Res are
discussed.Comment: 14 pages, 01 figur
Optimization for continuous overflow proteolytic hydrolysis of spent brewer’s yeast by using proteases
A large amount of spent yeast as by-product is annually generated from brewing industry and it contains about 50-55% protein with good balance of amino acids. The hydrolysate produced from spent brewer’s yeast may be used in food application. The yield of proteolylic hydrolysis for spent brewer’s yeast and amino acid contents of hydrolysates depend on factors such as temperature, pH value, type of used enzyme and ratio enzyme/substrate, time. Besides, applied hydrolysing methods (batch-, or continuous method) has effected on degree of hydrolysis. With the purpose of how proteolytic hydrolysis having effects on the spent brewer’s yeast for food application in industrial scale, continuous overflow method was used in this study. Bitterness of hydrolysate and the yield of continuous overflow proteolytic hydrolysis process are the two interested factors for protein hydrolysis. In this report, it is dealt with determination for optimal conditions to obtain the highest yield of hydrolysis process and the lowest bitterness of hydrolysate. Response surface methodology (RSM) was used to determine optimal condition for continuous overflow proteolytic hydrolysis of spent brewer’s yeast. The optimal conditions for obtaining high degree of hydrolysis and low bitterness are determined as followings: ratio of enzyme mixture (alcalase 7.5 U/g and flavourzyme 10 U/g), pH at 7.5, hydrolysis temperature at 51oC and hydrolysis time of 9 hours. Under the optimal conditions, the yield of hydrolysis was 59.62% ± 0.027 and the bitterness equivalently with concentration of quinine was 7.86 ± 0.033 μmol /ml
One-pot microwave-assisted green synthesis of amine-functionalized graphene quantum dots for high visible light photocatalytic application
Nowadays, graphene quantum dots (GQDs) have gained a huge interest in the field of visible-range photocatalysts because of their tunable band gap and stable photochemical properties. In this work, amine-functionalized GQDs (AGQDs) were successfully prepared by one-step microwave-assisted conversion of glucose, H2O2, and NH3 solution. The obtained quantum dots possess the high quality of graphene structure with the average size of 3.78 nm as well as exhibit a strong green fluorescence with a high quantum yield. Interestingly, the amine-functionalized dots perform outstanding visible-light absorption. To further investigate photocatalytic properties, a composite of AGQDs and TiO2 was then prepared by a simple mixing route. The hybrid material showed high catalytic activity of dye degradation under visible light irradiation, which indicates the key role of AGQDs in enhancing light absorption and induced electron–hole separation. The current study may open a new way for construction of effective visible light photocatalytic systems with a cost-effective, simple approach.Scopu
XGV-BERT: Leveraging Contextualized Language Model and Graph Neural Network for Efficient Software Vulnerability Detection
With the advancement of deep learning (DL) in various fields, there are many
attempts to reveal software vulnerabilities by data-driven approach.
Nonetheless, such existing works lack the effective representation that can
retain the non-sequential semantic characteristics and contextual relationship
of source code attributes. Hence, in this work, we propose XGV-BERT, a
framework that combines the pre-trained CodeBERT model and Graph Neural Network
(GCN) to detect software vulnerabilities. By jointly training the CodeBERT and
GCN modules within XGV-BERT, the proposed model leverages the advantages of
large-scale pre-training, harnessing vast raw data, and transfer learning by
learning representations for training data through graph convolution. The
research results demonstrate that the XGV-BERT method significantly improves
vulnerability detection accuracy compared to two existing methods such as
VulDeePecker and SySeVR. For the VulDeePecker dataset, XGV-BERT achieves an
impressive F1-score of 97.5%, significantly outperforming VulDeePecker, which
achieved an F1-score of 78.3%. Again, with the SySeVR dataset, XGV-BERT
achieves an F1-score of 95.5%, surpassing the results of SySeVR with an
F1-score of 83.5%
Anti-DreamBooth: Protecting users from personalized text-to-image synthesis
Text-to-image diffusion models are nothing but a revolution, allowing anyone,
even without design skills, to create realistic images from simple text inputs.
With powerful personalization tools like DreamBooth, they can generate images
of a specific person just by learning from his/her few reference images.
However, when misused, such a powerful and convenient tool can produce fake
news or disturbing content targeting any individual victim, posing a severe
negative social impact. In this paper, we explore a defense system called
Anti-DreamBooth against such malicious use of DreamBooth. The system aims to
add subtle noise perturbation to each user's image before publishing in order
to disrupt the generation quality of any DreamBooth model trained on these
perturbed images. We investigate a wide range of algorithms for perturbation
optimization and extensively evaluate them on two facial datasets over various
text-to-image model versions. Despite the complicated formulation of DreamBooth
and Diffusion-based text-to-image models, our methods effectively defend users
from the malicious use of those models. Their effectiveness withstands even
adverse conditions, such as model or prompt/term mismatching between training
and testing. Our code will be available at
\href{https://github.com/VinAIResearch/Anti-DreamBooth.git}{https://github.com/VinAIResearch/Anti-DreamBooth.git}.Comment: Project page: https://anti-dreambooth.github.io
The Spitzer View of Low-Metallicity Star Formation: III. Fine Structure Lines, Aromatic Features, and Molecules
We present low- and high-resolution Spitzer/IRS spectra, supplemented by IRAC
and MIPS measurements, of 22 blue compact dwarf (BCD) galaxies. The BCD sample
spans a wide range in oxygen abundance [12+Log(O/H) between 7.4 and 8.3], and
hardness of the interstellar radiation field (ISRF). The IRS spectra provide us
with a rich set of diagnostics to probe the physics of star and dust formation
in very low-metallicity environments. We find that metal-poor BCDs have harder
ionizing radiation than metal-rich galaxies: [OIV] emission is roughly 4 times
as common as [FeII] emission. They also have a more intense ISRF, as indicated
by the 71 to 160micron luminosity ratio. Two-thirds of the sample (15 BCDs)
show PAH features, although the fraction of PAH emission normalized to the
total infrared (IR) luminosity is considerably smaller in metal-poor BCDs
(~0.5%) than in metal-rich star-forming galaxies (~10%). We find several lines
of evidence for a deficit of small PAH carriers at low metallicity, and
attribute this to destruction by a hard, intense ISRF, only indirectly linked
to metal abundance. Our IRS spectra reveal a variety of H2 rotational lines,
and more than a third of the objects in our sample (8 BCDs) have >=3sigma
detections in one or more of the four lowest-order transitions. The warm gas
masses in the BCDs range from 10^3 to 10^8 Msun, and can be comparable to the
neutral hydrogen gas mass; relative to their total IR luminosities, some BCDs
contain more H2 than SINGS galaxies.Comment: Accepted by ApJ: 70 pages in draft form, 6 tables, 22 figure
Exploiting Secrecy Performance of Uplink NOMA in Cellular Networks
Funding Information: This work was supported in part by the Air Force Office of Scientific Research under Award FA9550-20-1-0090, and in part by the National Science Foundation under Grant CNS-2034218.Peer reviewedPublisher PD
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